1.PROJECT PLANING Before starting every project its planning is to be done. Planning is very important task and should be taken with great care, as the efficiency of the whole project largely depends upon its planning while planning a project each and every details should be worked out in anticipation and should carefully is considered with all the relating provisions in advance. Project planning consists of the following steps. PROJECT CAPACITY The capacity of the project must be decided considering the amount of money which can be invested and availability of material and machines. DRAWINGS Drawing been decided for the project to be manufacture. Its detailed drawing specification for raw material and finished products should be decided carefully along with the specification of the machines required for their manufacture.
Final Report
Nov 03, 2014
multi speed gear box
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Transcript
1PROJECT PLANING
Before starting every project its planning is to be done Planning is very
important task and should be taken with great care as the efficiency of the whole
project largely depends upon its planning while planning a project each and every
details should be worked out in anticipation and should carefully is considered
with all the relating provisions in advance Project planning consists of the
following steps
PROJECT CAPACITYThe capacity of the project must be decided considering the amount of
money which can be invested and availability of material and machines
DRAWINGSDrawing been decided for the project to be manufacture Its detailed drawing
specification for raw material and finished products should be decided carefully
along with the specification of the machines required for their manufacture
MATERIAL EQUIPMENTThe list of materials required for manufacture is prepared from the drawings
The list of is known as ldquoBILL OF MATERIALSrdquo This passes to the store keeper
and the required materials taken from the store under permission of store keeper
operation the necessity of operation the person to do the job machine to be used
to do the job are considered while planning the operation After considering tea
above questions a best method is developed and the best method is applied to the
operation
MACHINE LODINGWhile planning proper care should be taken to find the machining time for
each operation as correct as possible So that the arrangement for full utilization of
machine can be made machine loading programmed is also known
PURCHASE CONSIDERATION It is different to manufacture all the component needed for the equipment in
the workshop itself The decision about a particular item whether to purchase or to
manufacture is taken by planning after making through study of relative merits
demerits
EQUIPMENT CONSIDERATIONResult obtained from ldquoPROCESS PLANNINGrdquo and ldquoMACHINE LODINGrdquo
helps in calculating the equipment requirement specification of the equipment
should be laid down by considering the drawing Drawing will also help in
deciding and necessary requirement of tools accessories
COST CALCULATIONThe cost of the project can be calculated by adding following
1 Material Cost
2 Machining Cost
3 Overhead Expenses
COMPARIONThe various items in the finished project are compared to the standards for
the further correction
REPORT At the end of the project work report is prepared for future references The
report consists of all the items done the project work
2 INTRODUCTION OF GEAR BOX
Gears are a means of power transmission and changing the rate of rotation of a
machinery shaft They can also change the direction of the axis of rotation and can
change rotary motion to linear motion Unfortunately mechanical engineers
sometimes shy away from the use of gears and rely on the advent of electronic
controls and the availability of toothed belts since robust gears for high-speed
andor high-power machinery are often very complex to design However for
dedicated high-speed machinery such as an automobile transmission gears are the
optimal medium for low energy loss high accuracy and low play
The intricacies of a gearrsquos terrain offer challenges to even the most experienced
quality control engineer As gear specifications tighten tolerances often drop to the
submicron realm Hobbing shaving and grinding machines that offer already high
accuracies can lag behind the quality demands of their finished product Culprits
include uneven or incorrectly mounted cutting tools the results of which manifest
themselves in profile errors flankline deviation variation in tooth thickness pitch
error and deviations in flank shape A gear that deviates from the ideal will make
itself heard and seen Substandard gears are noisy during operation wear down
quickly and fail prematurely
Here we present a broad and comprehensive report on Gear Metrology explaining
Gear classification and terminology Metrological aspects of Gears (Cylindrical
parallel axis involute gears) Standards of Gear measurements Measurement
techniques and Measuring equipment This report is intended to formalize the
procedures used for measuring lead profile and pitch errors in involute gears using
dedicated gear measuring machines and CMMrsquos with gear measurement software
It should be used when gear tolerances are specified in accordance with existing
gear standards (eg ISO 1328 AGMA 3902 BS 436) and assumes that basic
background knowledge of involute geometry and the measurement techniques are
familiar to the reader ISO Technical Report TR 10064-1 1992 1 background
information is recommended for more detailed study
3GEAR CLASSIFICATION
Gears are of several categories and can be combined in a multitude of ways some
of which are illustrated in the following figures
SPUR GEAR Spur gears are the most common type of gear having radial teeth
parallel to the axle They have straight teeth and are mounted on parallel shafts
Sometimes many spur gears are used at once to create very large gear reductions
Each time a gear tooth engages a tooth on the other gear the teeth collide and this
impact makes a noise It also increases the stress on the gear teeth
HELICAL GEAR A gear wheel meshed with another so that their shafts are at an
angle less than 180 degrees The teeth on helical gears are cut at an angle to the
face of the gear When two teeth on a helical gear system engage the contact starts
at one end of the tooth and gradually spreads as the gears rotate until the two teeth
are in full engagement This gradual engagement makes helical gears operate much
more smoothly and quietly than spur gears For this reason helical gears are used
in almost all car transmissions Because of the angle of the teeth on helical gears
they create a thrust load on the gear when they mesh Devices that use helical gears
have bearings that can support this thrust load One interesting thing about helical
gears is that if the angles of the gear teeth are correct they can be mounted on
perpendicular shafts adjusting the rotation angle by 90 degrees
WORM GEAR A short rotating screw that meshes with the teeth of another gear
As a worm gear is an inclined plane it will be the driving gear in most cases
Worm gears are used when large gear reductions are needed It is common for
worm gears to have reductions of 201 and even up to 3001 or greater Many
worm gears have an interesting property that no other gear set has the worm can
easily turn the gear but the gear cannot turn the worm This is because the angle
on the worm is so shallow that when the gear tries to spin it the friction between
the gear and the worm holds the worm in place This feature is useful for machines
such as conveyor systems in which the locking feature can act as a brake for the
conveyor when the motor is not turning One other very interesting usage of worm
gears is in the Torsen differential which is used on some high performance cars
and trucks
BEVEL GEAR Bevel gears are used to connect shafts which intersect usually but
not necessarily at 90 degrees The teeth on a bevel gear are subjected to much the
same action as spur gear teeth Bevel gears are not interchangeable and in
consequence are designed in pairs (except in the case of mitre bevel gears)
DIFFERENTIAL GEAR A certain arrangement of gears connecting two axles in
the same line and dividing the driving force between them but allowing one axle
to turn faster than the other It is used in the rear axles of automobiles to permit a
difference in axle speeds while turning
RACK GEAR A toothed bar into which a ldquopinionrdquo (worm gear spur etc) meshes
Rack and pinion gears are used to convert rotation into linear motion A perfect
example of this is the steering system on many cars The steering wheel rotates a
gear which engages the rack As the gear turns it slides the rack either to the right
or left depending on which way you turn the wheel
PINION A small cogwheel the teeth of which fit into those of a larger gearwheel
or those of a rack
COGWHEEL A wheel with a rim notched into teeth which meshes with those of
another wheel or a rack to transmit or receive motion
4 GEAR TERMINOLOGY
Fig 1 Gear Specification
DEFINITIONS
1 Addendum The distance a tooth projects above or outside of the pitch line or
circle
2 Base circle The base circle is a circle from which involute tooth profiles are
derived
3 Base cylinder The base cylinder corresponds to the base circle and is the
cylinder from which involute tooth surfaces either straight or helical are derived
4 Backlash The amount by which the width of a tooth space exceeds the thickness
of the engaging tooth on the operating pitch circles Backlash is the gap between
gear teeth where they mesh This leads to lsquoplayrsquo in the gears
5 Bottom Land The root diameter
6 Chordal Addendum The distance from the outer diameter to the pitch line
7 Chordal Thickness The tooth thickness at the pitch line
8 Circular Pitch The distance from the center of one tooth to the center of the next
tooth measured round the circumference of the pitch circle
9 Clearance The amount by which the Dedendum of a gear tooth exceeds the
addendum of a mating gear
10 Center distance The distance from the center of the gear shaft to the center of
the pinion shaft
11 Circular tooth thickness The length of arc between the two sides of the same
gear tooth on a specified circle (Refer figure 1)
12 Datum circle The datum circle is a circle on which measurements are made
13 Composite action test A method of gear inspection in which the work gear is
rolled in tight double-flank contact with a master gear or a specified gear to
determine composite variations
14 Composite tolerance tooth-to-tooth (double-flank) The permissible amount of
tooth-to-tooth composite variation
15 Composite tolerance total (double-flank) The permissible amount of total
composite variation
16 Composite variation Variation in center distance when a gear is inspected by a
composite-action test
17 Composite variation tooth to tooth (double-flank) The greatest change in
center distance while the gear being tested is rotated through any angle of 360degN
during a double flank composite test
18 Total Composite variation (double-flank) The total change in center distance
while the gear being tested is rotated one complete revolution during double-flank
composite-action test
19 Datum of axis rotation The axis of the gear used as the basis for
measurements
20 Datum tooth The designated tooth used as the starting point for measuring
other teeth
21 Diameter profile control The specified diameter of the circle beyond which
the tooth profile must conform to the specified involute curve
22 Dedendum The depth of a tooth space below or inside of the pitch circle
23 Eccentricity The distance between the center of a datum circle and a datum
axis of rotation
24 Face width The length of the gear teeth in an axial plane
25 Functional face width The portion of the face width less the edge round at
each end
26 Index variation The displacement of any tooth from its theoretical position
relative to a datum tooth Measurements are usually linear near the middle of the
functional tooth profile If the measurements are made normal to the tooth surface
they should be corrected to the transverse plane
27 Total Index variation The maximum algebric difference between the extreme
values of index variation for a given gear Total index variation is also equivalent
to total accumulated pitch variation measured by a two probe spacing system
28 Lead The axial advance of a helix for one revolution (see Fig2)
Fig 2 Tooth Thickeness
29 Master gear A gear of known quality that is used to perform a composite-
action test
30 Outside diameter The diameter of the addendum circle (outside) of a
cylindrical gear
31 Pitch The distance between similar equally spaced tooth surfaces along a
given line or arc (See Fig 3)
Fig 3 Lead (top) and various pitches (bottom)
32 Axial pitch The pitch of a gear parallel to the axis of rotation
33 Base pitch On an involute gear the base pitch is the pitch on the base circle or
along the line of action It is equal to the circumference of the base circle divided
by the number of teeth
34 Circular Pitch The distance along a specified pitch circle or pitch line between
corresponding profiles of adjacent teeth (See Fig 3)
35 Diametral pitch The diameter of the pitch circle The ratio of the number of
teeth to the pitch diameter in the transverse It is equal to pi divided by the circular
pitch
36 Normal diametral pitch The ration of the number of teeth to the pitch diameter
in the normal plane of a helical gear The normal plane and transverse of a spur
gear are coincident
37 Pitch variation The plus or minus difference in the transverse plane between
the average measured pitch and the actual pitch measurement (See Fig 4)
Fig 4 Pitch Variation
38 Pressure Angle The angle between a tooth profile and a radial line at its pitch
point It is usually equal to 20 degrees
39 Normal pressure angle The angle at a point on the pitch cylinder between the
line of pressure that is normal to the tooth surface and the plane tangent to the pitch
cylinder
40 Profile One side of a tooth in a cross section between the out side circle and
the rootcircle
Fig 5 Profile
41 Functional profile The portion of the tooth flank between the profile control
diameter and the addendum circle or the start of tip round
Fig 6 Functional profile
42 Profile variation The difference between the measured and the specified
functional profile If measured in a normal plane a correction using the appropriate
helix angle must be applied to the measured value
Fig 7 Profile Variation
43 Profile tolerance The permissible amount of profile variation in the functional
profile designated by a specified lsquoKrsquo chart envelope as shown in figure 8 Plus
material at the tip which increases the amount of variation outside the functional
profile is not acceptable Minus material beyond the start of tip can be
disregarded
MEASUREMENT OF GEAR ACCURACY
The methods of testing and measuring gears depend largely on the class of gear
the method of manufacture and the equipment available Because even the
smallest out-of- spec gear can halt operations gear manufacturers have many
inspection options for both functional and analytical evaluation Functional gaging
or ldquoattribute inspectionrdquo offers a quick go or no-go method to check whether a
gear is ldquogoodrdquo or ldquobadrdquo and whether it will function as intended To determine
whether a part meets dimensional specifications gear manufacturers rely on
analytical testing Such analysis is reserved for trouble shooting situations when a
manufacturer is looking for the source of a problem in the gear machining process
The numbers of instrumentation options for both types of dimensional test make
deciding on the correct measurement solution dicey The correct system depends
on the type of gear being measured and the application for which it is intended
Gears with parallel axes are much simpler to gage than those with cross axes and
require a standard rather than customized solution Similarly if a manufacturer is
held to strict tight tolerances on a gear for use in a medical device then accuracy
will determine the choice In terms of application do you want to control your
manufacturing process or inspect a gear to specifications Depending on the
answer yoursquoll need a functional or analytical measurement system
FUNCTIONAL GEAR CHECKING
Functional testing is a qualitative form of inspection to determine whether a gear
will work as intended The most basic form of functional gear test equipment
involves a single-flank or double-flank meshing arrangement between a master
gear and a production gear Another checking methods related to functional
checking is tooth contact or bearing pattern checking Functional or composite gear
checking involves rolling two gears together and measuring the resultant motion
The gears rolled together can be either work and master gears or two work gears
Single-flank configurations display transmission errors of only one flank at a time
Double-flank models display center distance variation and the performance of both
flanks simultaneously Double-flank gear testers expose radial eccentricity or out-
of-round errors but they donrsquot detect angular tooth position defects which can be a
source of transmission errors These testers can find nonsystematic errors
including burrs nicks or hard spots and they enable an inspector to determine
functional tooth thickness
To use a basic functional gear tester the operator mounts a gear on a spindle
brings it to zero backlash mesh and rotates it for one revolution of the production
gear He can then determine center distance variation between the gears Manually
operated systems enable in-process auditing and provide quick visual verification
that the gear falls within specifications
For a test thatrsquos free of operator influence and is faster in analysis throughput
computerized models are a better option Computerized systems can separate
measurements into their finer elements If we want to know just the runout
characteristic of a gear and separate the tooth-to-tooth rolling action we need a
computerized model to do that The computer can separate and give value for
runout tooth-to-tooth and maximum and minimum defects If we try to read those
elements with a dial indicator [a manually operated gear checker] they would flash
so fast that our eyes could never see them
5COMPONENTS OF N-SEREIES GEAR BOX
In our project the following components are involved to achieve the
indefinite speed
1 Structure
2 Flat belt
3 Plummer block
4 Roller
5 Screw rod
6 Ball bearing
7 Handle
51 STRUCTURE
Structural steel is steel construction material a profile formed with a specific
shape or cross section and certain standards of chemical composition and strength
Structural steel shape size composition strength storage etc is regulated in most
industrialized countries
Structural steel members such as I-beams have high second moments of area
which allow them to be very stiff in respect to their cross-sectional area
A steel I-beam in this case used to support wood beams in a house
Structural steel in construction A primed steel beam is holding up the floor above
which consists of a metal deck (Q-Deck) upon which a concrete slab has been
poured
Steel beam through-penetration with incomplete fireproofing
Metal deck and OWSJ (Open Web Steel Joist) receiving first coat of spray
fireproofing plaster made of polystyrene leavened gypsum Contents
1 Common structural shapes
2 Standards
21 Standard structural steels
22 Standard structural steels
221 Carbon steels
222 High strength low alloy steels
223 Corrosion resistant high strength low alloy steels
224 Quenched and tempered alloy steels
3 Steel vs concrete
4 Thermal properties
5 Fireproofing of structural steel
COMMON STRUCTURAL SHAPES
In most developed countries the shapes available are set out in published
standards although a number of specialist and proprietary cross sections are also
available
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB)
and Universal Columns (UC) in Europe it includes the IPE HE HL HD and other
sections in the US it includes Wide Flange (WF) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow
section) and including square rectangular circular (pipe) and elliptical cross
sections)
Angle (L-shaped cross-section)
Channel ( [-shaped cross-section)
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar a piece of metal rectangular cross sectioned (flat) and long but not so wide so
as to be called a sheet
Rod a round or square and long piece of metal or wood see also rebar and dowel
Plate sheet metal thicker than 6 mm or 14 in
Open web steel joist
While many sections are made by hot or cold rolling others are made by welding
together flat or bent plates (for example the largest circular hollow sections are
made from flat plate bent into a circle and seam-welded)
Standard structural steels
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
MACHINE LODINGWhile planning proper care should be taken to find the machining time for
each operation as correct as possible So that the arrangement for full utilization of
machine can be made machine loading programmed is also known
PURCHASE CONSIDERATION It is different to manufacture all the component needed for the equipment in
the workshop itself The decision about a particular item whether to purchase or to
manufacture is taken by planning after making through study of relative merits
demerits
EQUIPMENT CONSIDERATIONResult obtained from ldquoPROCESS PLANNINGrdquo and ldquoMACHINE LODINGrdquo
helps in calculating the equipment requirement specification of the equipment
should be laid down by considering the drawing Drawing will also help in
deciding and necessary requirement of tools accessories
COST CALCULATIONThe cost of the project can be calculated by adding following
1 Material Cost
2 Machining Cost
3 Overhead Expenses
COMPARIONThe various items in the finished project are compared to the standards for
the further correction
REPORT At the end of the project work report is prepared for future references The
report consists of all the items done the project work
2 INTRODUCTION OF GEAR BOX
Gears are a means of power transmission and changing the rate of rotation of a
machinery shaft They can also change the direction of the axis of rotation and can
change rotary motion to linear motion Unfortunately mechanical engineers
sometimes shy away from the use of gears and rely on the advent of electronic
controls and the availability of toothed belts since robust gears for high-speed
andor high-power machinery are often very complex to design However for
dedicated high-speed machinery such as an automobile transmission gears are the
optimal medium for low energy loss high accuracy and low play
The intricacies of a gearrsquos terrain offer challenges to even the most experienced
quality control engineer As gear specifications tighten tolerances often drop to the
submicron realm Hobbing shaving and grinding machines that offer already high
accuracies can lag behind the quality demands of their finished product Culprits
include uneven or incorrectly mounted cutting tools the results of which manifest
themselves in profile errors flankline deviation variation in tooth thickness pitch
error and deviations in flank shape A gear that deviates from the ideal will make
itself heard and seen Substandard gears are noisy during operation wear down
quickly and fail prematurely
Here we present a broad and comprehensive report on Gear Metrology explaining
Gear classification and terminology Metrological aspects of Gears (Cylindrical
parallel axis involute gears) Standards of Gear measurements Measurement
techniques and Measuring equipment This report is intended to formalize the
procedures used for measuring lead profile and pitch errors in involute gears using
dedicated gear measuring machines and CMMrsquos with gear measurement software
It should be used when gear tolerances are specified in accordance with existing
gear standards (eg ISO 1328 AGMA 3902 BS 436) and assumes that basic
background knowledge of involute geometry and the measurement techniques are
familiar to the reader ISO Technical Report TR 10064-1 1992 1 background
information is recommended for more detailed study
3GEAR CLASSIFICATION
Gears are of several categories and can be combined in a multitude of ways some
of which are illustrated in the following figures
SPUR GEAR Spur gears are the most common type of gear having radial teeth
parallel to the axle They have straight teeth and are mounted on parallel shafts
Sometimes many spur gears are used at once to create very large gear reductions
Each time a gear tooth engages a tooth on the other gear the teeth collide and this
impact makes a noise It also increases the stress on the gear teeth
HELICAL GEAR A gear wheel meshed with another so that their shafts are at an
angle less than 180 degrees The teeth on helical gears are cut at an angle to the
face of the gear When two teeth on a helical gear system engage the contact starts
at one end of the tooth and gradually spreads as the gears rotate until the two teeth
are in full engagement This gradual engagement makes helical gears operate much
more smoothly and quietly than spur gears For this reason helical gears are used
in almost all car transmissions Because of the angle of the teeth on helical gears
they create a thrust load on the gear when they mesh Devices that use helical gears
have bearings that can support this thrust load One interesting thing about helical
gears is that if the angles of the gear teeth are correct they can be mounted on
perpendicular shafts adjusting the rotation angle by 90 degrees
WORM GEAR A short rotating screw that meshes with the teeth of another gear
As a worm gear is an inclined plane it will be the driving gear in most cases
Worm gears are used when large gear reductions are needed It is common for
worm gears to have reductions of 201 and even up to 3001 or greater Many
worm gears have an interesting property that no other gear set has the worm can
easily turn the gear but the gear cannot turn the worm This is because the angle
on the worm is so shallow that when the gear tries to spin it the friction between
the gear and the worm holds the worm in place This feature is useful for machines
such as conveyor systems in which the locking feature can act as a brake for the
conveyor when the motor is not turning One other very interesting usage of worm
gears is in the Torsen differential which is used on some high performance cars
and trucks
BEVEL GEAR Bevel gears are used to connect shafts which intersect usually but
not necessarily at 90 degrees The teeth on a bevel gear are subjected to much the
same action as spur gear teeth Bevel gears are not interchangeable and in
consequence are designed in pairs (except in the case of mitre bevel gears)
DIFFERENTIAL GEAR A certain arrangement of gears connecting two axles in
the same line and dividing the driving force between them but allowing one axle
to turn faster than the other It is used in the rear axles of automobiles to permit a
difference in axle speeds while turning
RACK GEAR A toothed bar into which a ldquopinionrdquo (worm gear spur etc) meshes
Rack and pinion gears are used to convert rotation into linear motion A perfect
example of this is the steering system on many cars The steering wheel rotates a
gear which engages the rack As the gear turns it slides the rack either to the right
or left depending on which way you turn the wheel
PINION A small cogwheel the teeth of which fit into those of a larger gearwheel
or those of a rack
COGWHEEL A wheel with a rim notched into teeth which meshes with those of
another wheel or a rack to transmit or receive motion
4 GEAR TERMINOLOGY
Fig 1 Gear Specification
DEFINITIONS
1 Addendum The distance a tooth projects above or outside of the pitch line or
circle
2 Base circle The base circle is a circle from which involute tooth profiles are
derived
3 Base cylinder The base cylinder corresponds to the base circle and is the
cylinder from which involute tooth surfaces either straight or helical are derived
4 Backlash The amount by which the width of a tooth space exceeds the thickness
of the engaging tooth on the operating pitch circles Backlash is the gap between
gear teeth where they mesh This leads to lsquoplayrsquo in the gears
5 Bottom Land The root diameter
6 Chordal Addendum The distance from the outer diameter to the pitch line
7 Chordal Thickness The tooth thickness at the pitch line
8 Circular Pitch The distance from the center of one tooth to the center of the next
tooth measured round the circumference of the pitch circle
9 Clearance The amount by which the Dedendum of a gear tooth exceeds the
addendum of a mating gear
10 Center distance The distance from the center of the gear shaft to the center of
the pinion shaft
11 Circular tooth thickness The length of arc between the two sides of the same
gear tooth on a specified circle (Refer figure 1)
12 Datum circle The datum circle is a circle on which measurements are made
13 Composite action test A method of gear inspection in which the work gear is
rolled in tight double-flank contact with a master gear or a specified gear to
determine composite variations
14 Composite tolerance tooth-to-tooth (double-flank) The permissible amount of
tooth-to-tooth composite variation
15 Composite tolerance total (double-flank) The permissible amount of total
composite variation
16 Composite variation Variation in center distance when a gear is inspected by a
composite-action test
17 Composite variation tooth to tooth (double-flank) The greatest change in
center distance while the gear being tested is rotated through any angle of 360degN
during a double flank composite test
18 Total Composite variation (double-flank) The total change in center distance
while the gear being tested is rotated one complete revolution during double-flank
composite-action test
19 Datum of axis rotation The axis of the gear used as the basis for
measurements
20 Datum tooth The designated tooth used as the starting point for measuring
other teeth
21 Diameter profile control The specified diameter of the circle beyond which
the tooth profile must conform to the specified involute curve
22 Dedendum The depth of a tooth space below or inside of the pitch circle
23 Eccentricity The distance between the center of a datum circle and a datum
axis of rotation
24 Face width The length of the gear teeth in an axial plane
25 Functional face width The portion of the face width less the edge round at
each end
26 Index variation The displacement of any tooth from its theoretical position
relative to a datum tooth Measurements are usually linear near the middle of the
functional tooth profile If the measurements are made normal to the tooth surface
they should be corrected to the transverse plane
27 Total Index variation The maximum algebric difference between the extreme
values of index variation for a given gear Total index variation is also equivalent
to total accumulated pitch variation measured by a two probe spacing system
28 Lead The axial advance of a helix for one revolution (see Fig2)
Fig 2 Tooth Thickeness
29 Master gear A gear of known quality that is used to perform a composite-
action test
30 Outside diameter The diameter of the addendum circle (outside) of a
cylindrical gear
31 Pitch The distance between similar equally spaced tooth surfaces along a
given line or arc (See Fig 3)
Fig 3 Lead (top) and various pitches (bottom)
32 Axial pitch The pitch of a gear parallel to the axis of rotation
33 Base pitch On an involute gear the base pitch is the pitch on the base circle or
along the line of action It is equal to the circumference of the base circle divided
by the number of teeth
34 Circular Pitch The distance along a specified pitch circle or pitch line between
corresponding profiles of adjacent teeth (See Fig 3)
35 Diametral pitch The diameter of the pitch circle The ratio of the number of
teeth to the pitch diameter in the transverse It is equal to pi divided by the circular
pitch
36 Normal diametral pitch The ration of the number of teeth to the pitch diameter
in the normal plane of a helical gear The normal plane and transverse of a spur
gear are coincident
37 Pitch variation The plus or minus difference in the transverse plane between
the average measured pitch and the actual pitch measurement (See Fig 4)
Fig 4 Pitch Variation
38 Pressure Angle The angle between a tooth profile and a radial line at its pitch
point It is usually equal to 20 degrees
39 Normal pressure angle The angle at a point on the pitch cylinder between the
line of pressure that is normal to the tooth surface and the plane tangent to the pitch
cylinder
40 Profile One side of a tooth in a cross section between the out side circle and
the rootcircle
Fig 5 Profile
41 Functional profile The portion of the tooth flank between the profile control
diameter and the addendum circle or the start of tip round
Fig 6 Functional profile
42 Profile variation The difference between the measured and the specified
functional profile If measured in a normal plane a correction using the appropriate
helix angle must be applied to the measured value
Fig 7 Profile Variation
43 Profile tolerance The permissible amount of profile variation in the functional
profile designated by a specified lsquoKrsquo chart envelope as shown in figure 8 Plus
material at the tip which increases the amount of variation outside the functional
profile is not acceptable Minus material beyond the start of tip can be
disregarded
MEASUREMENT OF GEAR ACCURACY
The methods of testing and measuring gears depend largely on the class of gear
the method of manufacture and the equipment available Because even the
smallest out-of- spec gear can halt operations gear manufacturers have many
inspection options for both functional and analytical evaluation Functional gaging
or ldquoattribute inspectionrdquo offers a quick go or no-go method to check whether a
gear is ldquogoodrdquo or ldquobadrdquo and whether it will function as intended To determine
whether a part meets dimensional specifications gear manufacturers rely on
analytical testing Such analysis is reserved for trouble shooting situations when a
manufacturer is looking for the source of a problem in the gear machining process
The numbers of instrumentation options for both types of dimensional test make
deciding on the correct measurement solution dicey The correct system depends
on the type of gear being measured and the application for which it is intended
Gears with parallel axes are much simpler to gage than those with cross axes and
require a standard rather than customized solution Similarly if a manufacturer is
held to strict tight tolerances on a gear for use in a medical device then accuracy
will determine the choice In terms of application do you want to control your
manufacturing process or inspect a gear to specifications Depending on the
answer yoursquoll need a functional or analytical measurement system
FUNCTIONAL GEAR CHECKING
Functional testing is a qualitative form of inspection to determine whether a gear
will work as intended The most basic form of functional gear test equipment
involves a single-flank or double-flank meshing arrangement between a master
gear and a production gear Another checking methods related to functional
checking is tooth contact or bearing pattern checking Functional or composite gear
checking involves rolling two gears together and measuring the resultant motion
The gears rolled together can be either work and master gears or two work gears
Single-flank configurations display transmission errors of only one flank at a time
Double-flank models display center distance variation and the performance of both
flanks simultaneously Double-flank gear testers expose radial eccentricity or out-
of-round errors but they donrsquot detect angular tooth position defects which can be a
source of transmission errors These testers can find nonsystematic errors
including burrs nicks or hard spots and they enable an inspector to determine
functional tooth thickness
To use a basic functional gear tester the operator mounts a gear on a spindle
brings it to zero backlash mesh and rotates it for one revolution of the production
gear He can then determine center distance variation between the gears Manually
operated systems enable in-process auditing and provide quick visual verification
that the gear falls within specifications
For a test thatrsquos free of operator influence and is faster in analysis throughput
computerized models are a better option Computerized systems can separate
measurements into their finer elements If we want to know just the runout
characteristic of a gear and separate the tooth-to-tooth rolling action we need a
computerized model to do that The computer can separate and give value for
runout tooth-to-tooth and maximum and minimum defects If we try to read those
elements with a dial indicator [a manually operated gear checker] they would flash
so fast that our eyes could never see them
5COMPONENTS OF N-SEREIES GEAR BOX
In our project the following components are involved to achieve the
indefinite speed
1 Structure
2 Flat belt
3 Plummer block
4 Roller
5 Screw rod
6 Ball bearing
7 Handle
51 STRUCTURE
Structural steel is steel construction material a profile formed with a specific
shape or cross section and certain standards of chemical composition and strength
Structural steel shape size composition strength storage etc is regulated in most
industrialized countries
Structural steel members such as I-beams have high second moments of area
which allow them to be very stiff in respect to their cross-sectional area
A steel I-beam in this case used to support wood beams in a house
Structural steel in construction A primed steel beam is holding up the floor above
which consists of a metal deck (Q-Deck) upon which a concrete slab has been
poured
Steel beam through-penetration with incomplete fireproofing
Metal deck and OWSJ (Open Web Steel Joist) receiving first coat of spray
fireproofing plaster made of polystyrene leavened gypsum Contents
1 Common structural shapes
2 Standards
21 Standard structural steels
22 Standard structural steels
221 Carbon steels
222 High strength low alloy steels
223 Corrosion resistant high strength low alloy steels
224 Quenched and tempered alloy steels
3 Steel vs concrete
4 Thermal properties
5 Fireproofing of structural steel
COMMON STRUCTURAL SHAPES
In most developed countries the shapes available are set out in published
standards although a number of specialist and proprietary cross sections are also
available
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB)
and Universal Columns (UC) in Europe it includes the IPE HE HL HD and other
sections in the US it includes Wide Flange (WF) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow
section) and including square rectangular circular (pipe) and elliptical cross
sections)
Angle (L-shaped cross-section)
Channel ( [-shaped cross-section)
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar a piece of metal rectangular cross sectioned (flat) and long but not so wide so
as to be called a sheet
Rod a round or square and long piece of metal or wood see also rebar and dowel
Plate sheet metal thicker than 6 mm or 14 in
Open web steel joist
While many sections are made by hot or cold rolling others are made by welding
together flat or bent plates (for example the largest circular hollow sections are
made from flat plate bent into a circle and seam-welded)
Standard structural steels
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
REPORT At the end of the project work report is prepared for future references The
report consists of all the items done the project work
2 INTRODUCTION OF GEAR BOX
Gears are a means of power transmission and changing the rate of rotation of a
machinery shaft They can also change the direction of the axis of rotation and can
change rotary motion to linear motion Unfortunately mechanical engineers
sometimes shy away from the use of gears and rely on the advent of electronic
controls and the availability of toothed belts since robust gears for high-speed
andor high-power machinery are often very complex to design However for
dedicated high-speed machinery such as an automobile transmission gears are the
optimal medium for low energy loss high accuracy and low play
The intricacies of a gearrsquos terrain offer challenges to even the most experienced
quality control engineer As gear specifications tighten tolerances often drop to the
submicron realm Hobbing shaving and grinding machines that offer already high
accuracies can lag behind the quality demands of their finished product Culprits
include uneven or incorrectly mounted cutting tools the results of which manifest
themselves in profile errors flankline deviation variation in tooth thickness pitch
error and deviations in flank shape A gear that deviates from the ideal will make
itself heard and seen Substandard gears are noisy during operation wear down
quickly and fail prematurely
Here we present a broad and comprehensive report on Gear Metrology explaining
Gear classification and terminology Metrological aspects of Gears (Cylindrical
parallel axis involute gears) Standards of Gear measurements Measurement
techniques and Measuring equipment This report is intended to formalize the
procedures used for measuring lead profile and pitch errors in involute gears using
dedicated gear measuring machines and CMMrsquos with gear measurement software
It should be used when gear tolerances are specified in accordance with existing
gear standards (eg ISO 1328 AGMA 3902 BS 436) and assumes that basic
background knowledge of involute geometry and the measurement techniques are
familiar to the reader ISO Technical Report TR 10064-1 1992 1 background
information is recommended for more detailed study
3GEAR CLASSIFICATION
Gears are of several categories and can be combined in a multitude of ways some
of which are illustrated in the following figures
SPUR GEAR Spur gears are the most common type of gear having radial teeth
parallel to the axle They have straight teeth and are mounted on parallel shafts
Sometimes many spur gears are used at once to create very large gear reductions
Each time a gear tooth engages a tooth on the other gear the teeth collide and this
impact makes a noise It also increases the stress on the gear teeth
HELICAL GEAR A gear wheel meshed with another so that their shafts are at an
angle less than 180 degrees The teeth on helical gears are cut at an angle to the
face of the gear When two teeth on a helical gear system engage the contact starts
at one end of the tooth and gradually spreads as the gears rotate until the two teeth
are in full engagement This gradual engagement makes helical gears operate much
more smoothly and quietly than spur gears For this reason helical gears are used
in almost all car transmissions Because of the angle of the teeth on helical gears
they create a thrust load on the gear when they mesh Devices that use helical gears
have bearings that can support this thrust load One interesting thing about helical
gears is that if the angles of the gear teeth are correct they can be mounted on
perpendicular shafts adjusting the rotation angle by 90 degrees
WORM GEAR A short rotating screw that meshes with the teeth of another gear
As a worm gear is an inclined plane it will be the driving gear in most cases
Worm gears are used when large gear reductions are needed It is common for
worm gears to have reductions of 201 and even up to 3001 or greater Many
worm gears have an interesting property that no other gear set has the worm can
easily turn the gear but the gear cannot turn the worm This is because the angle
on the worm is so shallow that when the gear tries to spin it the friction between
the gear and the worm holds the worm in place This feature is useful for machines
such as conveyor systems in which the locking feature can act as a brake for the
conveyor when the motor is not turning One other very interesting usage of worm
gears is in the Torsen differential which is used on some high performance cars
and trucks
BEVEL GEAR Bevel gears are used to connect shafts which intersect usually but
not necessarily at 90 degrees The teeth on a bevel gear are subjected to much the
same action as spur gear teeth Bevel gears are not interchangeable and in
consequence are designed in pairs (except in the case of mitre bevel gears)
DIFFERENTIAL GEAR A certain arrangement of gears connecting two axles in
the same line and dividing the driving force between them but allowing one axle
to turn faster than the other It is used in the rear axles of automobiles to permit a
difference in axle speeds while turning
RACK GEAR A toothed bar into which a ldquopinionrdquo (worm gear spur etc) meshes
Rack and pinion gears are used to convert rotation into linear motion A perfect
example of this is the steering system on many cars The steering wheel rotates a
gear which engages the rack As the gear turns it slides the rack either to the right
or left depending on which way you turn the wheel
PINION A small cogwheel the teeth of which fit into those of a larger gearwheel
or those of a rack
COGWHEEL A wheel with a rim notched into teeth which meshes with those of
another wheel or a rack to transmit or receive motion
4 GEAR TERMINOLOGY
Fig 1 Gear Specification
DEFINITIONS
1 Addendum The distance a tooth projects above or outside of the pitch line or
circle
2 Base circle The base circle is a circle from which involute tooth profiles are
derived
3 Base cylinder The base cylinder corresponds to the base circle and is the
cylinder from which involute tooth surfaces either straight or helical are derived
4 Backlash The amount by which the width of a tooth space exceeds the thickness
of the engaging tooth on the operating pitch circles Backlash is the gap between
gear teeth where they mesh This leads to lsquoplayrsquo in the gears
5 Bottom Land The root diameter
6 Chordal Addendum The distance from the outer diameter to the pitch line
7 Chordal Thickness The tooth thickness at the pitch line
8 Circular Pitch The distance from the center of one tooth to the center of the next
tooth measured round the circumference of the pitch circle
9 Clearance The amount by which the Dedendum of a gear tooth exceeds the
addendum of a mating gear
10 Center distance The distance from the center of the gear shaft to the center of
the pinion shaft
11 Circular tooth thickness The length of arc between the two sides of the same
gear tooth on a specified circle (Refer figure 1)
12 Datum circle The datum circle is a circle on which measurements are made
13 Composite action test A method of gear inspection in which the work gear is
rolled in tight double-flank contact with a master gear or a specified gear to
determine composite variations
14 Composite tolerance tooth-to-tooth (double-flank) The permissible amount of
tooth-to-tooth composite variation
15 Composite tolerance total (double-flank) The permissible amount of total
composite variation
16 Composite variation Variation in center distance when a gear is inspected by a
composite-action test
17 Composite variation tooth to tooth (double-flank) The greatest change in
center distance while the gear being tested is rotated through any angle of 360degN
during a double flank composite test
18 Total Composite variation (double-flank) The total change in center distance
while the gear being tested is rotated one complete revolution during double-flank
composite-action test
19 Datum of axis rotation The axis of the gear used as the basis for
measurements
20 Datum tooth The designated tooth used as the starting point for measuring
other teeth
21 Diameter profile control The specified diameter of the circle beyond which
the tooth profile must conform to the specified involute curve
22 Dedendum The depth of a tooth space below or inside of the pitch circle
23 Eccentricity The distance between the center of a datum circle and a datum
axis of rotation
24 Face width The length of the gear teeth in an axial plane
25 Functional face width The portion of the face width less the edge round at
each end
26 Index variation The displacement of any tooth from its theoretical position
relative to a datum tooth Measurements are usually linear near the middle of the
functional tooth profile If the measurements are made normal to the tooth surface
they should be corrected to the transverse plane
27 Total Index variation The maximum algebric difference between the extreme
values of index variation for a given gear Total index variation is also equivalent
to total accumulated pitch variation measured by a two probe spacing system
28 Lead The axial advance of a helix for one revolution (see Fig2)
Fig 2 Tooth Thickeness
29 Master gear A gear of known quality that is used to perform a composite-
action test
30 Outside diameter The diameter of the addendum circle (outside) of a
cylindrical gear
31 Pitch The distance between similar equally spaced tooth surfaces along a
given line or arc (See Fig 3)
Fig 3 Lead (top) and various pitches (bottom)
32 Axial pitch The pitch of a gear parallel to the axis of rotation
33 Base pitch On an involute gear the base pitch is the pitch on the base circle or
along the line of action It is equal to the circumference of the base circle divided
by the number of teeth
34 Circular Pitch The distance along a specified pitch circle or pitch line between
corresponding profiles of adjacent teeth (See Fig 3)
35 Diametral pitch The diameter of the pitch circle The ratio of the number of
teeth to the pitch diameter in the transverse It is equal to pi divided by the circular
pitch
36 Normal diametral pitch The ration of the number of teeth to the pitch diameter
in the normal plane of a helical gear The normal plane and transverse of a spur
gear are coincident
37 Pitch variation The plus or minus difference in the transverse plane between
the average measured pitch and the actual pitch measurement (See Fig 4)
Fig 4 Pitch Variation
38 Pressure Angle The angle between a tooth profile and a radial line at its pitch
point It is usually equal to 20 degrees
39 Normal pressure angle The angle at a point on the pitch cylinder between the
line of pressure that is normal to the tooth surface and the plane tangent to the pitch
cylinder
40 Profile One side of a tooth in a cross section between the out side circle and
the rootcircle
Fig 5 Profile
41 Functional profile The portion of the tooth flank between the profile control
diameter and the addendum circle or the start of tip round
Fig 6 Functional profile
42 Profile variation The difference between the measured and the specified
functional profile If measured in a normal plane a correction using the appropriate
helix angle must be applied to the measured value
Fig 7 Profile Variation
43 Profile tolerance The permissible amount of profile variation in the functional
profile designated by a specified lsquoKrsquo chart envelope as shown in figure 8 Plus
material at the tip which increases the amount of variation outside the functional
profile is not acceptable Minus material beyond the start of tip can be
disregarded
MEASUREMENT OF GEAR ACCURACY
The methods of testing and measuring gears depend largely on the class of gear
the method of manufacture and the equipment available Because even the
smallest out-of- spec gear can halt operations gear manufacturers have many
inspection options for both functional and analytical evaluation Functional gaging
or ldquoattribute inspectionrdquo offers a quick go or no-go method to check whether a
gear is ldquogoodrdquo or ldquobadrdquo and whether it will function as intended To determine
whether a part meets dimensional specifications gear manufacturers rely on
analytical testing Such analysis is reserved for trouble shooting situations when a
manufacturer is looking for the source of a problem in the gear machining process
The numbers of instrumentation options for both types of dimensional test make
deciding on the correct measurement solution dicey The correct system depends
on the type of gear being measured and the application for which it is intended
Gears with parallel axes are much simpler to gage than those with cross axes and
require a standard rather than customized solution Similarly if a manufacturer is
held to strict tight tolerances on a gear for use in a medical device then accuracy
will determine the choice In terms of application do you want to control your
manufacturing process or inspect a gear to specifications Depending on the
answer yoursquoll need a functional or analytical measurement system
FUNCTIONAL GEAR CHECKING
Functional testing is a qualitative form of inspection to determine whether a gear
will work as intended The most basic form of functional gear test equipment
involves a single-flank or double-flank meshing arrangement between a master
gear and a production gear Another checking methods related to functional
checking is tooth contact or bearing pattern checking Functional or composite gear
checking involves rolling two gears together and measuring the resultant motion
The gears rolled together can be either work and master gears or two work gears
Single-flank configurations display transmission errors of only one flank at a time
Double-flank models display center distance variation and the performance of both
flanks simultaneously Double-flank gear testers expose radial eccentricity or out-
of-round errors but they donrsquot detect angular tooth position defects which can be a
source of transmission errors These testers can find nonsystematic errors
including burrs nicks or hard spots and they enable an inspector to determine
functional tooth thickness
To use a basic functional gear tester the operator mounts a gear on a spindle
brings it to zero backlash mesh and rotates it for one revolution of the production
gear He can then determine center distance variation between the gears Manually
operated systems enable in-process auditing and provide quick visual verification
that the gear falls within specifications
For a test thatrsquos free of operator influence and is faster in analysis throughput
computerized models are a better option Computerized systems can separate
measurements into their finer elements If we want to know just the runout
characteristic of a gear and separate the tooth-to-tooth rolling action we need a
computerized model to do that The computer can separate and give value for
runout tooth-to-tooth and maximum and minimum defects If we try to read those
elements with a dial indicator [a manually operated gear checker] they would flash
so fast that our eyes could never see them
5COMPONENTS OF N-SEREIES GEAR BOX
In our project the following components are involved to achieve the
indefinite speed
1 Structure
2 Flat belt
3 Plummer block
4 Roller
5 Screw rod
6 Ball bearing
7 Handle
51 STRUCTURE
Structural steel is steel construction material a profile formed with a specific
shape or cross section and certain standards of chemical composition and strength
Structural steel shape size composition strength storage etc is regulated in most
industrialized countries
Structural steel members such as I-beams have high second moments of area
which allow them to be very stiff in respect to their cross-sectional area
A steel I-beam in this case used to support wood beams in a house
Structural steel in construction A primed steel beam is holding up the floor above
which consists of a metal deck (Q-Deck) upon which a concrete slab has been
poured
Steel beam through-penetration with incomplete fireproofing
Metal deck and OWSJ (Open Web Steel Joist) receiving first coat of spray
fireproofing plaster made of polystyrene leavened gypsum Contents
1 Common structural shapes
2 Standards
21 Standard structural steels
22 Standard structural steels
221 Carbon steels
222 High strength low alloy steels
223 Corrosion resistant high strength low alloy steels
224 Quenched and tempered alloy steels
3 Steel vs concrete
4 Thermal properties
5 Fireproofing of structural steel
COMMON STRUCTURAL SHAPES
In most developed countries the shapes available are set out in published
standards although a number of specialist and proprietary cross sections are also
available
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB)
and Universal Columns (UC) in Europe it includes the IPE HE HL HD and other
sections in the US it includes Wide Flange (WF) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow
section) and including square rectangular circular (pipe) and elliptical cross
sections)
Angle (L-shaped cross-section)
Channel ( [-shaped cross-section)
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar a piece of metal rectangular cross sectioned (flat) and long but not so wide so
as to be called a sheet
Rod a round or square and long piece of metal or wood see also rebar and dowel
Plate sheet metal thicker than 6 mm or 14 in
Open web steel joist
While many sections are made by hot or cold rolling others are made by welding
together flat or bent plates (for example the largest circular hollow sections are
made from flat plate bent into a circle and seam-welded)
Standard structural steels
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
2 INTRODUCTION OF GEAR BOX
Gears are a means of power transmission and changing the rate of rotation of a
machinery shaft They can also change the direction of the axis of rotation and can
change rotary motion to linear motion Unfortunately mechanical engineers
sometimes shy away from the use of gears and rely on the advent of electronic
controls and the availability of toothed belts since robust gears for high-speed
andor high-power machinery are often very complex to design However for
dedicated high-speed machinery such as an automobile transmission gears are the
optimal medium for low energy loss high accuracy and low play
The intricacies of a gearrsquos terrain offer challenges to even the most experienced
quality control engineer As gear specifications tighten tolerances often drop to the
submicron realm Hobbing shaving and grinding machines that offer already high
accuracies can lag behind the quality demands of their finished product Culprits
include uneven or incorrectly mounted cutting tools the results of which manifest
themselves in profile errors flankline deviation variation in tooth thickness pitch
error and deviations in flank shape A gear that deviates from the ideal will make
itself heard and seen Substandard gears are noisy during operation wear down
quickly and fail prematurely
Here we present a broad and comprehensive report on Gear Metrology explaining
Gear classification and terminology Metrological aspects of Gears (Cylindrical
parallel axis involute gears) Standards of Gear measurements Measurement
techniques and Measuring equipment This report is intended to formalize the
procedures used for measuring lead profile and pitch errors in involute gears using
dedicated gear measuring machines and CMMrsquos with gear measurement software
It should be used when gear tolerances are specified in accordance with existing
gear standards (eg ISO 1328 AGMA 3902 BS 436) and assumes that basic
background knowledge of involute geometry and the measurement techniques are
familiar to the reader ISO Technical Report TR 10064-1 1992 1 background
information is recommended for more detailed study
3GEAR CLASSIFICATION
Gears are of several categories and can be combined in a multitude of ways some
of which are illustrated in the following figures
SPUR GEAR Spur gears are the most common type of gear having radial teeth
parallel to the axle They have straight teeth and are mounted on parallel shafts
Sometimes many spur gears are used at once to create very large gear reductions
Each time a gear tooth engages a tooth on the other gear the teeth collide and this
impact makes a noise It also increases the stress on the gear teeth
HELICAL GEAR A gear wheel meshed with another so that their shafts are at an
angle less than 180 degrees The teeth on helical gears are cut at an angle to the
face of the gear When two teeth on a helical gear system engage the contact starts
at one end of the tooth and gradually spreads as the gears rotate until the two teeth
are in full engagement This gradual engagement makes helical gears operate much
more smoothly and quietly than spur gears For this reason helical gears are used
in almost all car transmissions Because of the angle of the teeth on helical gears
they create a thrust load on the gear when they mesh Devices that use helical gears
have bearings that can support this thrust load One interesting thing about helical
gears is that if the angles of the gear teeth are correct they can be mounted on
perpendicular shafts adjusting the rotation angle by 90 degrees
WORM GEAR A short rotating screw that meshes with the teeth of another gear
As a worm gear is an inclined plane it will be the driving gear in most cases
Worm gears are used when large gear reductions are needed It is common for
worm gears to have reductions of 201 and even up to 3001 or greater Many
worm gears have an interesting property that no other gear set has the worm can
easily turn the gear but the gear cannot turn the worm This is because the angle
on the worm is so shallow that when the gear tries to spin it the friction between
the gear and the worm holds the worm in place This feature is useful for machines
such as conveyor systems in which the locking feature can act as a brake for the
conveyor when the motor is not turning One other very interesting usage of worm
gears is in the Torsen differential which is used on some high performance cars
and trucks
BEVEL GEAR Bevel gears are used to connect shafts which intersect usually but
not necessarily at 90 degrees The teeth on a bevel gear are subjected to much the
same action as spur gear teeth Bevel gears are not interchangeable and in
consequence are designed in pairs (except in the case of mitre bevel gears)
DIFFERENTIAL GEAR A certain arrangement of gears connecting two axles in
the same line and dividing the driving force between them but allowing one axle
to turn faster than the other It is used in the rear axles of automobiles to permit a
difference in axle speeds while turning
RACK GEAR A toothed bar into which a ldquopinionrdquo (worm gear spur etc) meshes
Rack and pinion gears are used to convert rotation into linear motion A perfect
example of this is the steering system on many cars The steering wheel rotates a
gear which engages the rack As the gear turns it slides the rack either to the right
or left depending on which way you turn the wheel
PINION A small cogwheel the teeth of which fit into those of a larger gearwheel
or those of a rack
COGWHEEL A wheel with a rim notched into teeth which meshes with those of
another wheel or a rack to transmit or receive motion
4 GEAR TERMINOLOGY
Fig 1 Gear Specification
DEFINITIONS
1 Addendum The distance a tooth projects above or outside of the pitch line or
circle
2 Base circle The base circle is a circle from which involute tooth profiles are
derived
3 Base cylinder The base cylinder corresponds to the base circle and is the
cylinder from which involute tooth surfaces either straight or helical are derived
4 Backlash The amount by which the width of a tooth space exceeds the thickness
of the engaging tooth on the operating pitch circles Backlash is the gap between
gear teeth where they mesh This leads to lsquoplayrsquo in the gears
5 Bottom Land The root diameter
6 Chordal Addendum The distance from the outer diameter to the pitch line
7 Chordal Thickness The tooth thickness at the pitch line
8 Circular Pitch The distance from the center of one tooth to the center of the next
tooth measured round the circumference of the pitch circle
9 Clearance The amount by which the Dedendum of a gear tooth exceeds the
addendum of a mating gear
10 Center distance The distance from the center of the gear shaft to the center of
the pinion shaft
11 Circular tooth thickness The length of arc between the two sides of the same
gear tooth on a specified circle (Refer figure 1)
12 Datum circle The datum circle is a circle on which measurements are made
13 Composite action test A method of gear inspection in which the work gear is
rolled in tight double-flank contact with a master gear or a specified gear to
determine composite variations
14 Composite tolerance tooth-to-tooth (double-flank) The permissible amount of
tooth-to-tooth composite variation
15 Composite tolerance total (double-flank) The permissible amount of total
composite variation
16 Composite variation Variation in center distance when a gear is inspected by a
composite-action test
17 Composite variation tooth to tooth (double-flank) The greatest change in
center distance while the gear being tested is rotated through any angle of 360degN
during a double flank composite test
18 Total Composite variation (double-flank) The total change in center distance
while the gear being tested is rotated one complete revolution during double-flank
composite-action test
19 Datum of axis rotation The axis of the gear used as the basis for
measurements
20 Datum tooth The designated tooth used as the starting point for measuring
other teeth
21 Diameter profile control The specified diameter of the circle beyond which
the tooth profile must conform to the specified involute curve
22 Dedendum The depth of a tooth space below or inside of the pitch circle
23 Eccentricity The distance between the center of a datum circle and a datum
axis of rotation
24 Face width The length of the gear teeth in an axial plane
25 Functional face width The portion of the face width less the edge round at
each end
26 Index variation The displacement of any tooth from its theoretical position
relative to a datum tooth Measurements are usually linear near the middle of the
functional tooth profile If the measurements are made normal to the tooth surface
they should be corrected to the transverse plane
27 Total Index variation The maximum algebric difference between the extreme
values of index variation for a given gear Total index variation is also equivalent
to total accumulated pitch variation measured by a two probe spacing system
28 Lead The axial advance of a helix for one revolution (see Fig2)
Fig 2 Tooth Thickeness
29 Master gear A gear of known quality that is used to perform a composite-
action test
30 Outside diameter The diameter of the addendum circle (outside) of a
cylindrical gear
31 Pitch The distance between similar equally spaced tooth surfaces along a
given line or arc (See Fig 3)
Fig 3 Lead (top) and various pitches (bottom)
32 Axial pitch The pitch of a gear parallel to the axis of rotation
33 Base pitch On an involute gear the base pitch is the pitch on the base circle or
along the line of action It is equal to the circumference of the base circle divided
by the number of teeth
34 Circular Pitch The distance along a specified pitch circle or pitch line between
corresponding profiles of adjacent teeth (See Fig 3)
35 Diametral pitch The diameter of the pitch circle The ratio of the number of
teeth to the pitch diameter in the transverse It is equal to pi divided by the circular
pitch
36 Normal diametral pitch The ration of the number of teeth to the pitch diameter
in the normal plane of a helical gear The normal plane and transverse of a spur
gear are coincident
37 Pitch variation The plus or minus difference in the transverse plane between
the average measured pitch and the actual pitch measurement (See Fig 4)
Fig 4 Pitch Variation
38 Pressure Angle The angle between a tooth profile and a radial line at its pitch
point It is usually equal to 20 degrees
39 Normal pressure angle The angle at a point on the pitch cylinder between the
line of pressure that is normal to the tooth surface and the plane tangent to the pitch
cylinder
40 Profile One side of a tooth in a cross section between the out side circle and
the rootcircle
Fig 5 Profile
41 Functional profile The portion of the tooth flank between the profile control
diameter and the addendum circle or the start of tip round
Fig 6 Functional profile
42 Profile variation The difference between the measured and the specified
functional profile If measured in a normal plane a correction using the appropriate
helix angle must be applied to the measured value
Fig 7 Profile Variation
43 Profile tolerance The permissible amount of profile variation in the functional
profile designated by a specified lsquoKrsquo chart envelope as shown in figure 8 Plus
material at the tip which increases the amount of variation outside the functional
profile is not acceptable Minus material beyond the start of tip can be
disregarded
MEASUREMENT OF GEAR ACCURACY
The methods of testing and measuring gears depend largely on the class of gear
the method of manufacture and the equipment available Because even the
smallest out-of- spec gear can halt operations gear manufacturers have many
inspection options for both functional and analytical evaluation Functional gaging
or ldquoattribute inspectionrdquo offers a quick go or no-go method to check whether a
gear is ldquogoodrdquo or ldquobadrdquo and whether it will function as intended To determine
whether a part meets dimensional specifications gear manufacturers rely on
analytical testing Such analysis is reserved for trouble shooting situations when a
manufacturer is looking for the source of a problem in the gear machining process
The numbers of instrumentation options for both types of dimensional test make
deciding on the correct measurement solution dicey The correct system depends
on the type of gear being measured and the application for which it is intended
Gears with parallel axes are much simpler to gage than those with cross axes and
require a standard rather than customized solution Similarly if a manufacturer is
held to strict tight tolerances on a gear for use in a medical device then accuracy
will determine the choice In terms of application do you want to control your
manufacturing process or inspect a gear to specifications Depending on the
answer yoursquoll need a functional or analytical measurement system
FUNCTIONAL GEAR CHECKING
Functional testing is a qualitative form of inspection to determine whether a gear
will work as intended The most basic form of functional gear test equipment
involves a single-flank or double-flank meshing arrangement between a master
gear and a production gear Another checking methods related to functional
checking is tooth contact or bearing pattern checking Functional or composite gear
checking involves rolling two gears together and measuring the resultant motion
The gears rolled together can be either work and master gears or two work gears
Single-flank configurations display transmission errors of only one flank at a time
Double-flank models display center distance variation and the performance of both
flanks simultaneously Double-flank gear testers expose radial eccentricity or out-
of-round errors but they donrsquot detect angular tooth position defects which can be a
source of transmission errors These testers can find nonsystematic errors
including burrs nicks or hard spots and they enable an inspector to determine
functional tooth thickness
To use a basic functional gear tester the operator mounts a gear on a spindle
brings it to zero backlash mesh and rotates it for one revolution of the production
gear He can then determine center distance variation between the gears Manually
operated systems enable in-process auditing and provide quick visual verification
that the gear falls within specifications
For a test thatrsquos free of operator influence and is faster in analysis throughput
computerized models are a better option Computerized systems can separate
measurements into their finer elements If we want to know just the runout
characteristic of a gear and separate the tooth-to-tooth rolling action we need a
computerized model to do that The computer can separate and give value for
runout tooth-to-tooth and maximum and minimum defects If we try to read those
elements with a dial indicator [a manually operated gear checker] they would flash
so fast that our eyes could never see them
5COMPONENTS OF N-SEREIES GEAR BOX
In our project the following components are involved to achieve the
indefinite speed
1 Structure
2 Flat belt
3 Plummer block
4 Roller
5 Screw rod
6 Ball bearing
7 Handle
51 STRUCTURE
Structural steel is steel construction material a profile formed with a specific
shape or cross section and certain standards of chemical composition and strength
Structural steel shape size composition strength storage etc is regulated in most
industrialized countries
Structural steel members such as I-beams have high second moments of area
which allow them to be very stiff in respect to their cross-sectional area
A steel I-beam in this case used to support wood beams in a house
Structural steel in construction A primed steel beam is holding up the floor above
which consists of a metal deck (Q-Deck) upon which a concrete slab has been
poured
Steel beam through-penetration with incomplete fireproofing
Metal deck and OWSJ (Open Web Steel Joist) receiving first coat of spray
fireproofing plaster made of polystyrene leavened gypsum Contents
1 Common structural shapes
2 Standards
21 Standard structural steels
22 Standard structural steels
221 Carbon steels
222 High strength low alloy steels
223 Corrosion resistant high strength low alloy steels
224 Quenched and tempered alloy steels
3 Steel vs concrete
4 Thermal properties
5 Fireproofing of structural steel
COMMON STRUCTURAL SHAPES
In most developed countries the shapes available are set out in published
standards although a number of specialist and proprietary cross sections are also
available
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB)
and Universal Columns (UC) in Europe it includes the IPE HE HL HD and other
sections in the US it includes Wide Flange (WF) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow
section) and including square rectangular circular (pipe) and elliptical cross
sections)
Angle (L-shaped cross-section)
Channel ( [-shaped cross-section)
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar a piece of metal rectangular cross sectioned (flat) and long but not so wide so
as to be called a sheet
Rod a round or square and long piece of metal or wood see also rebar and dowel
Plate sheet metal thicker than 6 mm or 14 in
Open web steel joist
While many sections are made by hot or cold rolling others are made by welding
together flat or bent plates (for example the largest circular hollow sections are
made from flat plate bent into a circle and seam-welded)
Standard structural steels
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
gear standards (eg ISO 1328 AGMA 3902 BS 436) and assumes that basic
background knowledge of involute geometry and the measurement techniques are
familiar to the reader ISO Technical Report TR 10064-1 1992 1 background
information is recommended for more detailed study
3GEAR CLASSIFICATION
Gears are of several categories and can be combined in a multitude of ways some
of which are illustrated in the following figures
SPUR GEAR Spur gears are the most common type of gear having radial teeth
parallel to the axle They have straight teeth and are mounted on parallel shafts
Sometimes many spur gears are used at once to create very large gear reductions
Each time a gear tooth engages a tooth on the other gear the teeth collide and this
impact makes a noise It also increases the stress on the gear teeth
HELICAL GEAR A gear wheel meshed with another so that their shafts are at an
angle less than 180 degrees The teeth on helical gears are cut at an angle to the
face of the gear When two teeth on a helical gear system engage the contact starts
at one end of the tooth and gradually spreads as the gears rotate until the two teeth
are in full engagement This gradual engagement makes helical gears operate much
more smoothly and quietly than spur gears For this reason helical gears are used
in almost all car transmissions Because of the angle of the teeth on helical gears
they create a thrust load on the gear when they mesh Devices that use helical gears
have bearings that can support this thrust load One interesting thing about helical
gears is that if the angles of the gear teeth are correct they can be mounted on
perpendicular shafts adjusting the rotation angle by 90 degrees
WORM GEAR A short rotating screw that meshes with the teeth of another gear
As a worm gear is an inclined plane it will be the driving gear in most cases
Worm gears are used when large gear reductions are needed It is common for
worm gears to have reductions of 201 and even up to 3001 or greater Many
worm gears have an interesting property that no other gear set has the worm can
easily turn the gear but the gear cannot turn the worm This is because the angle
on the worm is so shallow that when the gear tries to spin it the friction between
the gear and the worm holds the worm in place This feature is useful for machines
such as conveyor systems in which the locking feature can act as a brake for the
conveyor when the motor is not turning One other very interesting usage of worm
gears is in the Torsen differential which is used on some high performance cars
and trucks
BEVEL GEAR Bevel gears are used to connect shafts which intersect usually but
not necessarily at 90 degrees The teeth on a bevel gear are subjected to much the
same action as spur gear teeth Bevel gears are not interchangeable and in
consequence are designed in pairs (except in the case of mitre bevel gears)
DIFFERENTIAL GEAR A certain arrangement of gears connecting two axles in
the same line and dividing the driving force between them but allowing one axle
to turn faster than the other It is used in the rear axles of automobiles to permit a
difference in axle speeds while turning
RACK GEAR A toothed bar into which a ldquopinionrdquo (worm gear spur etc) meshes
Rack and pinion gears are used to convert rotation into linear motion A perfect
example of this is the steering system on many cars The steering wheel rotates a
gear which engages the rack As the gear turns it slides the rack either to the right
or left depending on which way you turn the wheel
PINION A small cogwheel the teeth of which fit into those of a larger gearwheel
or those of a rack
COGWHEEL A wheel with a rim notched into teeth which meshes with those of
another wheel or a rack to transmit or receive motion
4 GEAR TERMINOLOGY
Fig 1 Gear Specification
DEFINITIONS
1 Addendum The distance a tooth projects above or outside of the pitch line or
circle
2 Base circle The base circle is a circle from which involute tooth profiles are
derived
3 Base cylinder The base cylinder corresponds to the base circle and is the
cylinder from which involute tooth surfaces either straight or helical are derived
4 Backlash The amount by which the width of a tooth space exceeds the thickness
of the engaging tooth on the operating pitch circles Backlash is the gap between
gear teeth where they mesh This leads to lsquoplayrsquo in the gears
5 Bottom Land The root diameter
6 Chordal Addendum The distance from the outer diameter to the pitch line
7 Chordal Thickness The tooth thickness at the pitch line
8 Circular Pitch The distance from the center of one tooth to the center of the next
tooth measured round the circumference of the pitch circle
9 Clearance The amount by which the Dedendum of a gear tooth exceeds the
addendum of a mating gear
10 Center distance The distance from the center of the gear shaft to the center of
the pinion shaft
11 Circular tooth thickness The length of arc between the two sides of the same
gear tooth on a specified circle (Refer figure 1)
12 Datum circle The datum circle is a circle on which measurements are made
13 Composite action test A method of gear inspection in which the work gear is
rolled in tight double-flank contact with a master gear or a specified gear to
determine composite variations
14 Composite tolerance tooth-to-tooth (double-flank) The permissible amount of
tooth-to-tooth composite variation
15 Composite tolerance total (double-flank) The permissible amount of total
composite variation
16 Composite variation Variation in center distance when a gear is inspected by a
composite-action test
17 Composite variation tooth to tooth (double-flank) The greatest change in
center distance while the gear being tested is rotated through any angle of 360degN
during a double flank composite test
18 Total Composite variation (double-flank) The total change in center distance
while the gear being tested is rotated one complete revolution during double-flank
composite-action test
19 Datum of axis rotation The axis of the gear used as the basis for
measurements
20 Datum tooth The designated tooth used as the starting point for measuring
other teeth
21 Diameter profile control The specified diameter of the circle beyond which
the tooth profile must conform to the specified involute curve
22 Dedendum The depth of a tooth space below or inside of the pitch circle
23 Eccentricity The distance between the center of a datum circle and a datum
axis of rotation
24 Face width The length of the gear teeth in an axial plane
25 Functional face width The portion of the face width less the edge round at
each end
26 Index variation The displacement of any tooth from its theoretical position
relative to a datum tooth Measurements are usually linear near the middle of the
functional tooth profile If the measurements are made normal to the tooth surface
they should be corrected to the transverse plane
27 Total Index variation The maximum algebric difference between the extreme
values of index variation for a given gear Total index variation is also equivalent
to total accumulated pitch variation measured by a two probe spacing system
28 Lead The axial advance of a helix for one revolution (see Fig2)
Fig 2 Tooth Thickeness
29 Master gear A gear of known quality that is used to perform a composite-
action test
30 Outside diameter The diameter of the addendum circle (outside) of a
cylindrical gear
31 Pitch The distance between similar equally spaced tooth surfaces along a
given line or arc (See Fig 3)
Fig 3 Lead (top) and various pitches (bottom)
32 Axial pitch The pitch of a gear parallel to the axis of rotation
33 Base pitch On an involute gear the base pitch is the pitch on the base circle or
along the line of action It is equal to the circumference of the base circle divided
by the number of teeth
34 Circular Pitch The distance along a specified pitch circle or pitch line between
corresponding profiles of adjacent teeth (See Fig 3)
35 Diametral pitch The diameter of the pitch circle The ratio of the number of
teeth to the pitch diameter in the transverse It is equal to pi divided by the circular
pitch
36 Normal diametral pitch The ration of the number of teeth to the pitch diameter
in the normal plane of a helical gear The normal plane and transverse of a spur
gear are coincident
37 Pitch variation The plus or minus difference in the transverse plane between
the average measured pitch and the actual pitch measurement (See Fig 4)
Fig 4 Pitch Variation
38 Pressure Angle The angle between a tooth profile and a radial line at its pitch
point It is usually equal to 20 degrees
39 Normal pressure angle The angle at a point on the pitch cylinder between the
line of pressure that is normal to the tooth surface and the plane tangent to the pitch
cylinder
40 Profile One side of a tooth in a cross section between the out side circle and
the rootcircle
Fig 5 Profile
41 Functional profile The portion of the tooth flank between the profile control
diameter and the addendum circle or the start of tip round
Fig 6 Functional profile
42 Profile variation The difference between the measured and the specified
functional profile If measured in a normal plane a correction using the appropriate
helix angle must be applied to the measured value
Fig 7 Profile Variation
43 Profile tolerance The permissible amount of profile variation in the functional
profile designated by a specified lsquoKrsquo chart envelope as shown in figure 8 Plus
material at the tip which increases the amount of variation outside the functional
profile is not acceptable Minus material beyond the start of tip can be
disregarded
MEASUREMENT OF GEAR ACCURACY
The methods of testing and measuring gears depend largely on the class of gear
the method of manufacture and the equipment available Because even the
smallest out-of- spec gear can halt operations gear manufacturers have many
inspection options for both functional and analytical evaluation Functional gaging
or ldquoattribute inspectionrdquo offers a quick go or no-go method to check whether a
gear is ldquogoodrdquo or ldquobadrdquo and whether it will function as intended To determine
whether a part meets dimensional specifications gear manufacturers rely on
analytical testing Such analysis is reserved for trouble shooting situations when a
manufacturer is looking for the source of a problem in the gear machining process
The numbers of instrumentation options for both types of dimensional test make
deciding on the correct measurement solution dicey The correct system depends
on the type of gear being measured and the application for which it is intended
Gears with parallel axes are much simpler to gage than those with cross axes and
require a standard rather than customized solution Similarly if a manufacturer is
held to strict tight tolerances on a gear for use in a medical device then accuracy
will determine the choice In terms of application do you want to control your
manufacturing process or inspect a gear to specifications Depending on the
answer yoursquoll need a functional or analytical measurement system
FUNCTIONAL GEAR CHECKING
Functional testing is a qualitative form of inspection to determine whether a gear
will work as intended The most basic form of functional gear test equipment
involves a single-flank or double-flank meshing arrangement between a master
gear and a production gear Another checking methods related to functional
checking is tooth contact or bearing pattern checking Functional or composite gear
checking involves rolling two gears together and measuring the resultant motion
The gears rolled together can be either work and master gears or two work gears
Single-flank configurations display transmission errors of only one flank at a time
Double-flank models display center distance variation and the performance of both
flanks simultaneously Double-flank gear testers expose radial eccentricity or out-
of-round errors but they donrsquot detect angular tooth position defects which can be a
source of transmission errors These testers can find nonsystematic errors
including burrs nicks or hard spots and they enable an inspector to determine
functional tooth thickness
To use a basic functional gear tester the operator mounts a gear on a spindle
brings it to zero backlash mesh and rotates it for one revolution of the production
gear He can then determine center distance variation between the gears Manually
operated systems enable in-process auditing and provide quick visual verification
that the gear falls within specifications
For a test thatrsquos free of operator influence and is faster in analysis throughput
computerized models are a better option Computerized systems can separate
measurements into their finer elements If we want to know just the runout
characteristic of a gear and separate the tooth-to-tooth rolling action we need a
computerized model to do that The computer can separate and give value for
runout tooth-to-tooth and maximum and minimum defects If we try to read those
elements with a dial indicator [a manually operated gear checker] they would flash
so fast that our eyes could never see them
5COMPONENTS OF N-SEREIES GEAR BOX
In our project the following components are involved to achieve the
indefinite speed
1 Structure
2 Flat belt
3 Plummer block
4 Roller
5 Screw rod
6 Ball bearing
7 Handle
51 STRUCTURE
Structural steel is steel construction material a profile formed with a specific
shape or cross section and certain standards of chemical composition and strength
Structural steel shape size composition strength storage etc is regulated in most
industrialized countries
Structural steel members such as I-beams have high second moments of area
which allow them to be very stiff in respect to their cross-sectional area
A steel I-beam in this case used to support wood beams in a house
Structural steel in construction A primed steel beam is holding up the floor above
which consists of a metal deck (Q-Deck) upon which a concrete slab has been
poured
Steel beam through-penetration with incomplete fireproofing
Metal deck and OWSJ (Open Web Steel Joist) receiving first coat of spray
fireproofing plaster made of polystyrene leavened gypsum Contents
1 Common structural shapes
2 Standards
21 Standard structural steels
22 Standard structural steels
221 Carbon steels
222 High strength low alloy steels
223 Corrosion resistant high strength low alloy steels
224 Quenched and tempered alloy steels
3 Steel vs concrete
4 Thermal properties
5 Fireproofing of structural steel
COMMON STRUCTURAL SHAPES
In most developed countries the shapes available are set out in published
standards although a number of specialist and proprietary cross sections are also
available
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB)
and Universal Columns (UC) in Europe it includes the IPE HE HL HD and other
sections in the US it includes Wide Flange (WF) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow
section) and including square rectangular circular (pipe) and elliptical cross
sections)
Angle (L-shaped cross-section)
Channel ( [-shaped cross-section)
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar a piece of metal rectangular cross sectioned (flat) and long but not so wide so
as to be called a sheet
Rod a round or square and long piece of metal or wood see also rebar and dowel
Plate sheet metal thicker than 6 mm or 14 in
Open web steel joist
While many sections are made by hot or cold rolling others are made by welding
together flat or bent plates (for example the largest circular hollow sections are
made from flat plate bent into a circle and seam-welded)
Standard structural steels
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
3GEAR CLASSIFICATION
Gears are of several categories and can be combined in a multitude of ways some
of which are illustrated in the following figures
SPUR GEAR Spur gears are the most common type of gear having radial teeth
parallel to the axle They have straight teeth and are mounted on parallel shafts
Sometimes many spur gears are used at once to create very large gear reductions
Each time a gear tooth engages a tooth on the other gear the teeth collide and this
impact makes a noise It also increases the stress on the gear teeth
HELICAL GEAR A gear wheel meshed with another so that their shafts are at an
angle less than 180 degrees The teeth on helical gears are cut at an angle to the
face of the gear When two teeth on a helical gear system engage the contact starts
at one end of the tooth and gradually spreads as the gears rotate until the two teeth
are in full engagement This gradual engagement makes helical gears operate much
more smoothly and quietly than spur gears For this reason helical gears are used
in almost all car transmissions Because of the angle of the teeth on helical gears
they create a thrust load on the gear when they mesh Devices that use helical gears
have bearings that can support this thrust load One interesting thing about helical
gears is that if the angles of the gear teeth are correct they can be mounted on
perpendicular shafts adjusting the rotation angle by 90 degrees
WORM GEAR A short rotating screw that meshes with the teeth of another gear
As a worm gear is an inclined plane it will be the driving gear in most cases
Worm gears are used when large gear reductions are needed It is common for
worm gears to have reductions of 201 and even up to 3001 or greater Many
worm gears have an interesting property that no other gear set has the worm can
easily turn the gear but the gear cannot turn the worm This is because the angle
on the worm is so shallow that when the gear tries to spin it the friction between
the gear and the worm holds the worm in place This feature is useful for machines
such as conveyor systems in which the locking feature can act as a brake for the
conveyor when the motor is not turning One other very interesting usage of worm
gears is in the Torsen differential which is used on some high performance cars
and trucks
BEVEL GEAR Bevel gears are used to connect shafts which intersect usually but
not necessarily at 90 degrees The teeth on a bevel gear are subjected to much the
same action as spur gear teeth Bevel gears are not interchangeable and in
consequence are designed in pairs (except in the case of mitre bevel gears)
DIFFERENTIAL GEAR A certain arrangement of gears connecting two axles in
the same line and dividing the driving force between them but allowing one axle
to turn faster than the other It is used in the rear axles of automobiles to permit a
difference in axle speeds while turning
RACK GEAR A toothed bar into which a ldquopinionrdquo (worm gear spur etc) meshes
Rack and pinion gears are used to convert rotation into linear motion A perfect
example of this is the steering system on many cars The steering wheel rotates a
gear which engages the rack As the gear turns it slides the rack either to the right
or left depending on which way you turn the wheel
PINION A small cogwheel the teeth of which fit into those of a larger gearwheel
or those of a rack
COGWHEEL A wheel with a rim notched into teeth which meshes with those of
another wheel or a rack to transmit or receive motion
4 GEAR TERMINOLOGY
Fig 1 Gear Specification
DEFINITIONS
1 Addendum The distance a tooth projects above or outside of the pitch line or
circle
2 Base circle The base circle is a circle from which involute tooth profiles are
derived
3 Base cylinder The base cylinder corresponds to the base circle and is the
cylinder from which involute tooth surfaces either straight or helical are derived
4 Backlash The amount by which the width of a tooth space exceeds the thickness
of the engaging tooth on the operating pitch circles Backlash is the gap between
gear teeth where they mesh This leads to lsquoplayrsquo in the gears
5 Bottom Land The root diameter
6 Chordal Addendum The distance from the outer diameter to the pitch line
7 Chordal Thickness The tooth thickness at the pitch line
8 Circular Pitch The distance from the center of one tooth to the center of the next
tooth measured round the circumference of the pitch circle
9 Clearance The amount by which the Dedendum of a gear tooth exceeds the
addendum of a mating gear
10 Center distance The distance from the center of the gear shaft to the center of
the pinion shaft
11 Circular tooth thickness The length of arc between the two sides of the same
gear tooth on a specified circle (Refer figure 1)
12 Datum circle The datum circle is a circle on which measurements are made
13 Composite action test A method of gear inspection in which the work gear is
rolled in tight double-flank contact with a master gear or a specified gear to
determine composite variations
14 Composite tolerance tooth-to-tooth (double-flank) The permissible amount of
tooth-to-tooth composite variation
15 Composite tolerance total (double-flank) The permissible amount of total
composite variation
16 Composite variation Variation in center distance when a gear is inspected by a
composite-action test
17 Composite variation tooth to tooth (double-flank) The greatest change in
center distance while the gear being tested is rotated through any angle of 360degN
during a double flank composite test
18 Total Composite variation (double-flank) The total change in center distance
while the gear being tested is rotated one complete revolution during double-flank
composite-action test
19 Datum of axis rotation The axis of the gear used as the basis for
measurements
20 Datum tooth The designated tooth used as the starting point for measuring
other teeth
21 Diameter profile control The specified diameter of the circle beyond which
the tooth profile must conform to the specified involute curve
22 Dedendum The depth of a tooth space below or inside of the pitch circle
23 Eccentricity The distance between the center of a datum circle and a datum
axis of rotation
24 Face width The length of the gear teeth in an axial plane
25 Functional face width The portion of the face width less the edge round at
each end
26 Index variation The displacement of any tooth from its theoretical position
relative to a datum tooth Measurements are usually linear near the middle of the
functional tooth profile If the measurements are made normal to the tooth surface
they should be corrected to the transverse plane
27 Total Index variation The maximum algebric difference between the extreme
values of index variation for a given gear Total index variation is also equivalent
to total accumulated pitch variation measured by a two probe spacing system
28 Lead The axial advance of a helix for one revolution (see Fig2)
Fig 2 Tooth Thickeness
29 Master gear A gear of known quality that is used to perform a composite-
action test
30 Outside diameter The diameter of the addendum circle (outside) of a
cylindrical gear
31 Pitch The distance between similar equally spaced tooth surfaces along a
given line or arc (See Fig 3)
Fig 3 Lead (top) and various pitches (bottom)
32 Axial pitch The pitch of a gear parallel to the axis of rotation
33 Base pitch On an involute gear the base pitch is the pitch on the base circle or
along the line of action It is equal to the circumference of the base circle divided
by the number of teeth
34 Circular Pitch The distance along a specified pitch circle or pitch line between
corresponding profiles of adjacent teeth (See Fig 3)
35 Diametral pitch The diameter of the pitch circle The ratio of the number of
teeth to the pitch diameter in the transverse It is equal to pi divided by the circular
pitch
36 Normal diametral pitch The ration of the number of teeth to the pitch diameter
in the normal plane of a helical gear The normal plane and transverse of a spur
gear are coincident
37 Pitch variation The plus or minus difference in the transverse plane between
the average measured pitch and the actual pitch measurement (See Fig 4)
Fig 4 Pitch Variation
38 Pressure Angle The angle between a tooth profile and a radial line at its pitch
point It is usually equal to 20 degrees
39 Normal pressure angle The angle at a point on the pitch cylinder between the
line of pressure that is normal to the tooth surface and the plane tangent to the pitch
cylinder
40 Profile One side of a tooth in a cross section between the out side circle and
the rootcircle
Fig 5 Profile
41 Functional profile The portion of the tooth flank between the profile control
diameter and the addendum circle or the start of tip round
Fig 6 Functional profile
42 Profile variation The difference between the measured and the specified
functional profile If measured in a normal plane a correction using the appropriate
helix angle must be applied to the measured value
Fig 7 Profile Variation
43 Profile tolerance The permissible amount of profile variation in the functional
profile designated by a specified lsquoKrsquo chart envelope as shown in figure 8 Plus
material at the tip which increases the amount of variation outside the functional
profile is not acceptable Minus material beyond the start of tip can be
disregarded
MEASUREMENT OF GEAR ACCURACY
The methods of testing and measuring gears depend largely on the class of gear
the method of manufacture and the equipment available Because even the
smallest out-of- spec gear can halt operations gear manufacturers have many
inspection options for both functional and analytical evaluation Functional gaging
or ldquoattribute inspectionrdquo offers a quick go or no-go method to check whether a
gear is ldquogoodrdquo or ldquobadrdquo and whether it will function as intended To determine
whether a part meets dimensional specifications gear manufacturers rely on
analytical testing Such analysis is reserved for trouble shooting situations when a
manufacturer is looking for the source of a problem in the gear machining process
The numbers of instrumentation options for both types of dimensional test make
deciding on the correct measurement solution dicey The correct system depends
on the type of gear being measured and the application for which it is intended
Gears with parallel axes are much simpler to gage than those with cross axes and
require a standard rather than customized solution Similarly if a manufacturer is
held to strict tight tolerances on a gear for use in a medical device then accuracy
will determine the choice In terms of application do you want to control your
manufacturing process or inspect a gear to specifications Depending on the
answer yoursquoll need a functional or analytical measurement system
FUNCTIONAL GEAR CHECKING
Functional testing is a qualitative form of inspection to determine whether a gear
will work as intended The most basic form of functional gear test equipment
involves a single-flank or double-flank meshing arrangement between a master
gear and a production gear Another checking methods related to functional
checking is tooth contact or bearing pattern checking Functional or composite gear
checking involves rolling two gears together and measuring the resultant motion
The gears rolled together can be either work and master gears or two work gears
Single-flank configurations display transmission errors of only one flank at a time
Double-flank models display center distance variation and the performance of both
flanks simultaneously Double-flank gear testers expose radial eccentricity or out-
of-round errors but they donrsquot detect angular tooth position defects which can be a
source of transmission errors These testers can find nonsystematic errors
including burrs nicks or hard spots and they enable an inspector to determine
functional tooth thickness
To use a basic functional gear tester the operator mounts a gear on a spindle
brings it to zero backlash mesh and rotates it for one revolution of the production
gear He can then determine center distance variation between the gears Manually
operated systems enable in-process auditing and provide quick visual verification
that the gear falls within specifications
For a test thatrsquos free of operator influence and is faster in analysis throughput
computerized models are a better option Computerized systems can separate
measurements into their finer elements If we want to know just the runout
characteristic of a gear and separate the tooth-to-tooth rolling action we need a
computerized model to do that The computer can separate and give value for
runout tooth-to-tooth and maximum and minimum defects If we try to read those
elements with a dial indicator [a manually operated gear checker] they would flash
so fast that our eyes could never see them
5COMPONENTS OF N-SEREIES GEAR BOX
In our project the following components are involved to achieve the
indefinite speed
1 Structure
2 Flat belt
3 Plummer block
4 Roller
5 Screw rod
6 Ball bearing
7 Handle
51 STRUCTURE
Structural steel is steel construction material a profile formed with a specific
shape or cross section and certain standards of chemical composition and strength
Structural steel shape size composition strength storage etc is regulated in most
industrialized countries
Structural steel members such as I-beams have high second moments of area
which allow them to be very stiff in respect to their cross-sectional area
A steel I-beam in this case used to support wood beams in a house
Structural steel in construction A primed steel beam is holding up the floor above
which consists of a metal deck (Q-Deck) upon which a concrete slab has been
poured
Steel beam through-penetration with incomplete fireproofing
Metal deck and OWSJ (Open Web Steel Joist) receiving first coat of spray
fireproofing plaster made of polystyrene leavened gypsum Contents
1 Common structural shapes
2 Standards
21 Standard structural steels
22 Standard structural steels
221 Carbon steels
222 High strength low alloy steels
223 Corrosion resistant high strength low alloy steels
224 Quenched and tempered alloy steels
3 Steel vs concrete
4 Thermal properties
5 Fireproofing of structural steel
COMMON STRUCTURAL SHAPES
In most developed countries the shapes available are set out in published
standards although a number of specialist and proprietary cross sections are also
available
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB)
and Universal Columns (UC) in Europe it includes the IPE HE HL HD and other
sections in the US it includes Wide Flange (WF) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow
section) and including square rectangular circular (pipe) and elliptical cross
sections)
Angle (L-shaped cross-section)
Channel ( [-shaped cross-section)
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar a piece of metal rectangular cross sectioned (flat) and long but not so wide so
as to be called a sheet
Rod a round or square and long piece of metal or wood see also rebar and dowel
Plate sheet metal thicker than 6 mm or 14 in
Open web steel joist
While many sections are made by hot or cold rolling others are made by welding
together flat or bent plates (for example the largest circular hollow sections are
made from flat plate bent into a circle and seam-welded)
Standard structural steels
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
on the worm is so shallow that when the gear tries to spin it the friction between
the gear and the worm holds the worm in place This feature is useful for machines
such as conveyor systems in which the locking feature can act as a brake for the
conveyor when the motor is not turning One other very interesting usage of worm
gears is in the Torsen differential which is used on some high performance cars
and trucks
BEVEL GEAR Bevel gears are used to connect shafts which intersect usually but
not necessarily at 90 degrees The teeth on a bevel gear are subjected to much the
same action as spur gear teeth Bevel gears are not interchangeable and in
consequence are designed in pairs (except in the case of mitre bevel gears)
DIFFERENTIAL GEAR A certain arrangement of gears connecting two axles in
the same line and dividing the driving force between them but allowing one axle
to turn faster than the other It is used in the rear axles of automobiles to permit a
difference in axle speeds while turning
RACK GEAR A toothed bar into which a ldquopinionrdquo (worm gear spur etc) meshes
Rack and pinion gears are used to convert rotation into linear motion A perfect
example of this is the steering system on many cars The steering wheel rotates a
gear which engages the rack As the gear turns it slides the rack either to the right
or left depending on which way you turn the wheel
PINION A small cogwheel the teeth of which fit into those of a larger gearwheel
or those of a rack
COGWHEEL A wheel with a rim notched into teeth which meshes with those of
another wheel or a rack to transmit or receive motion
4 GEAR TERMINOLOGY
Fig 1 Gear Specification
DEFINITIONS
1 Addendum The distance a tooth projects above or outside of the pitch line or
circle
2 Base circle The base circle is a circle from which involute tooth profiles are
derived
3 Base cylinder The base cylinder corresponds to the base circle and is the
cylinder from which involute tooth surfaces either straight or helical are derived
4 Backlash The amount by which the width of a tooth space exceeds the thickness
of the engaging tooth on the operating pitch circles Backlash is the gap between
gear teeth where they mesh This leads to lsquoplayrsquo in the gears
5 Bottom Land The root diameter
6 Chordal Addendum The distance from the outer diameter to the pitch line
7 Chordal Thickness The tooth thickness at the pitch line
8 Circular Pitch The distance from the center of one tooth to the center of the next
tooth measured round the circumference of the pitch circle
9 Clearance The amount by which the Dedendum of a gear tooth exceeds the
addendum of a mating gear
10 Center distance The distance from the center of the gear shaft to the center of
the pinion shaft
11 Circular tooth thickness The length of arc between the two sides of the same
gear tooth on a specified circle (Refer figure 1)
12 Datum circle The datum circle is a circle on which measurements are made
13 Composite action test A method of gear inspection in which the work gear is
rolled in tight double-flank contact with a master gear or a specified gear to
determine composite variations
14 Composite tolerance tooth-to-tooth (double-flank) The permissible amount of
tooth-to-tooth composite variation
15 Composite tolerance total (double-flank) The permissible amount of total
composite variation
16 Composite variation Variation in center distance when a gear is inspected by a
composite-action test
17 Composite variation tooth to tooth (double-flank) The greatest change in
center distance while the gear being tested is rotated through any angle of 360degN
during a double flank composite test
18 Total Composite variation (double-flank) The total change in center distance
while the gear being tested is rotated one complete revolution during double-flank
composite-action test
19 Datum of axis rotation The axis of the gear used as the basis for
measurements
20 Datum tooth The designated tooth used as the starting point for measuring
other teeth
21 Diameter profile control The specified diameter of the circle beyond which
the tooth profile must conform to the specified involute curve
22 Dedendum The depth of a tooth space below or inside of the pitch circle
23 Eccentricity The distance between the center of a datum circle and a datum
axis of rotation
24 Face width The length of the gear teeth in an axial plane
25 Functional face width The portion of the face width less the edge round at
each end
26 Index variation The displacement of any tooth from its theoretical position
relative to a datum tooth Measurements are usually linear near the middle of the
functional tooth profile If the measurements are made normal to the tooth surface
they should be corrected to the transverse plane
27 Total Index variation The maximum algebric difference between the extreme
values of index variation for a given gear Total index variation is also equivalent
to total accumulated pitch variation measured by a two probe spacing system
28 Lead The axial advance of a helix for one revolution (see Fig2)
Fig 2 Tooth Thickeness
29 Master gear A gear of known quality that is used to perform a composite-
action test
30 Outside diameter The diameter of the addendum circle (outside) of a
cylindrical gear
31 Pitch The distance between similar equally spaced tooth surfaces along a
given line or arc (See Fig 3)
Fig 3 Lead (top) and various pitches (bottom)
32 Axial pitch The pitch of a gear parallel to the axis of rotation
33 Base pitch On an involute gear the base pitch is the pitch on the base circle or
along the line of action It is equal to the circumference of the base circle divided
by the number of teeth
34 Circular Pitch The distance along a specified pitch circle or pitch line between
corresponding profiles of adjacent teeth (See Fig 3)
35 Diametral pitch The diameter of the pitch circle The ratio of the number of
teeth to the pitch diameter in the transverse It is equal to pi divided by the circular
pitch
36 Normal diametral pitch The ration of the number of teeth to the pitch diameter
in the normal plane of a helical gear The normal plane and transverse of a spur
gear are coincident
37 Pitch variation The plus or minus difference in the transverse plane between
the average measured pitch and the actual pitch measurement (See Fig 4)
Fig 4 Pitch Variation
38 Pressure Angle The angle between a tooth profile and a radial line at its pitch
point It is usually equal to 20 degrees
39 Normal pressure angle The angle at a point on the pitch cylinder between the
line of pressure that is normal to the tooth surface and the plane tangent to the pitch
cylinder
40 Profile One side of a tooth in a cross section between the out side circle and
the rootcircle
Fig 5 Profile
41 Functional profile The portion of the tooth flank between the profile control
diameter and the addendum circle or the start of tip round
Fig 6 Functional profile
42 Profile variation The difference between the measured and the specified
functional profile If measured in a normal plane a correction using the appropriate
helix angle must be applied to the measured value
Fig 7 Profile Variation
43 Profile tolerance The permissible amount of profile variation in the functional
profile designated by a specified lsquoKrsquo chart envelope as shown in figure 8 Plus
material at the tip which increases the amount of variation outside the functional
profile is not acceptable Minus material beyond the start of tip can be
disregarded
MEASUREMENT OF GEAR ACCURACY
The methods of testing and measuring gears depend largely on the class of gear
the method of manufacture and the equipment available Because even the
smallest out-of- spec gear can halt operations gear manufacturers have many
inspection options for both functional and analytical evaluation Functional gaging
or ldquoattribute inspectionrdquo offers a quick go or no-go method to check whether a
gear is ldquogoodrdquo or ldquobadrdquo and whether it will function as intended To determine
whether a part meets dimensional specifications gear manufacturers rely on
analytical testing Such analysis is reserved for trouble shooting situations when a
manufacturer is looking for the source of a problem in the gear machining process
The numbers of instrumentation options for both types of dimensional test make
deciding on the correct measurement solution dicey The correct system depends
on the type of gear being measured and the application for which it is intended
Gears with parallel axes are much simpler to gage than those with cross axes and
require a standard rather than customized solution Similarly if a manufacturer is
held to strict tight tolerances on a gear for use in a medical device then accuracy
will determine the choice In terms of application do you want to control your
manufacturing process or inspect a gear to specifications Depending on the
answer yoursquoll need a functional or analytical measurement system
FUNCTIONAL GEAR CHECKING
Functional testing is a qualitative form of inspection to determine whether a gear
will work as intended The most basic form of functional gear test equipment
involves a single-flank or double-flank meshing arrangement between a master
gear and a production gear Another checking methods related to functional
checking is tooth contact or bearing pattern checking Functional or composite gear
checking involves rolling two gears together and measuring the resultant motion
The gears rolled together can be either work and master gears or two work gears
Single-flank configurations display transmission errors of only one flank at a time
Double-flank models display center distance variation and the performance of both
flanks simultaneously Double-flank gear testers expose radial eccentricity or out-
of-round errors but they donrsquot detect angular tooth position defects which can be a
source of transmission errors These testers can find nonsystematic errors
including burrs nicks or hard spots and they enable an inspector to determine
functional tooth thickness
To use a basic functional gear tester the operator mounts a gear on a spindle
brings it to zero backlash mesh and rotates it for one revolution of the production
gear He can then determine center distance variation between the gears Manually
operated systems enable in-process auditing and provide quick visual verification
that the gear falls within specifications
For a test thatrsquos free of operator influence and is faster in analysis throughput
computerized models are a better option Computerized systems can separate
measurements into their finer elements If we want to know just the runout
characteristic of a gear and separate the tooth-to-tooth rolling action we need a
computerized model to do that The computer can separate and give value for
runout tooth-to-tooth and maximum and minimum defects If we try to read those
elements with a dial indicator [a manually operated gear checker] they would flash
so fast that our eyes could never see them
5COMPONENTS OF N-SEREIES GEAR BOX
In our project the following components are involved to achieve the
indefinite speed
1 Structure
2 Flat belt
3 Plummer block
4 Roller
5 Screw rod
6 Ball bearing
7 Handle
51 STRUCTURE
Structural steel is steel construction material a profile formed with a specific
shape or cross section and certain standards of chemical composition and strength
Structural steel shape size composition strength storage etc is regulated in most
industrialized countries
Structural steel members such as I-beams have high second moments of area
which allow them to be very stiff in respect to their cross-sectional area
A steel I-beam in this case used to support wood beams in a house
Structural steel in construction A primed steel beam is holding up the floor above
which consists of a metal deck (Q-Deck) upon which a concrete slab has been
poured
Steel beam through-penetration with incomplete fireproofing
Metal deck and OWSJ (Open Web Steel Joist) receiving first coat of spray
fireproofing plaster made of polystyrene leavened gypsum Contents
1 Common structural shapes
2 Standards
21 Standard structural steels
22 Standard structural steels
221 Carbon steels
222 High strength low alloy steels
223 Corrosion resistant high strength low alloy steels
224 Quenched and tempered alloy steels
3 Steel vs concrete
4 Thermal properties
5 Fireproofing of structural steel
COMMON STRUCTURAL SHAPES
In most developed countries the shapes available are set out in published
standards although a number of specialist and proprietary cross sections are also
available
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB)
and Universal Columns (UC) in Europe it includes the IPE HE HL HD and other
sections in the US it includes Wide Flange (WF) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow
section) and including square rectangular circular (pipe) and elliptical cross
sections)
Angle (L-shaped cross-section)
Channel ( [-shaped cross-section)
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar a piece of metal rectangular cross sectioned (flat) and long but not so wide so
as to be called a sheet
Rod a round or square and long piece of metal or wood see also rebar and dowel
Plate sheet metal thicker than 6 mm or 14 in
Open web steel joist
While many sections are made by hot or cold rolling others are made by welding
together flat or bent plates (for example the largest circular hollow sections are
made from flat plate bent into a circle and seam-welded)
Standard structural steels
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
4 GEAR TERMINOLOGY
Fig 1 Gear Specification
DEFINITIONS
1 Addendum The distance a tooth projects above or outside of the pitch line or
circle
2 Base circle The base circle is a circle from which involute tooth profiles are
derived
3 Base cylinder The base cylinder corresponds to the base circle and is the
cylinder from which involute tooth surfaces either straight or helical are derived
4 Backlash The amount by which the width of a tooth space exceeds the thickness
of the engaging tooth on the operating pitch circles Backlash is the gap between
gear teeth where they mesh This leads to lsquoplayrsquo in the gears
5 Bottom Land The root diameter
6 Chordal Addendum The distance from the outer diameter to the pitch line
7 Chordal Thickness The tooth thickness at the pitch line
8 Circular Pitch The distance from the center of one tooth to the center of the next
tooth measured round the circumference of the pitch circle
9 Clearance The amount by which the Dedendum of a gear tooth exceeds the
addendum of a mating gear
10 Center distance The distance from the center of the gear shaft to the center of
the pinion shaft
11 Circular tooth thickness The length of arc between the two sides of the same
gear tooth on a specified circle (Refer figure 1)
12 Datum circle The datum circle is a circle on which measurements are made
13 Composite action test A method of gear inspection in which the work gear is
rolled in tight double-flank contact with a master gear or a specified gear to
determine composite variations
14 Composite tolerance tooth-to-tooth (double-flank) The permissible amount of
tooth-to-tooth composite variation
15 Composite tolerance total (double-flank) The permissible amount of total
composite variation
16 Composite variation Variation in center distance when a gear is inspected by a
composite-action test
17 Composite variation tooth to tooth (double-flank) The greatest change in
center distance while the gear being tested is rotated through any angle of 360degN
during a double flank composite test
18 Total Composite variation (double-flank) The total change in center distance
while the gear being tested is rotated one complete revolution during double-flank
composite-action test
19 Datum of axis rotation The axis of the gear used as the basis for
measurements
20 Datum tooth The designated tooth used as the starting point for measuring
other teeth
21 Diameter profile control The specified diameter of the circle beyond which
the tooth profile must conform to the specified involute curve
22 Dedendum The depth of a tooth space below or inside of the pitch circle
23 Eccentricity The distance between the center of a datum circle and a datum
axis of rotation
24 Face width The length of the gear teeth in an axial plane
25 Functional face width The portion of the face width less the edge round at
each end
26 Index variation The displacement of any tooth from its theoretical position
relative to a datum tooth Measurements are usually linear near the middle of the
functional tooth profile If the measurements are made normal to the tooth surface
they should be corrected to the transverse plane
27 Total Index variation The maximum algebric difference between the extreme
values of index variation for a given gear Total index variation is also equivalent
to total accumulated pitch variation measured by a two probe spacing system
28 Lead The axial advance of a helix for one revolution (see Fig2)
Fig 2 Tooth Thickeness
29 Master gear A gear of known quality that is used to perform a composite-
action test
30 Outside diameter The diameter of the addendum circle (outside) of a
cylindrical gear
31 Pitch The distance between similar equally spaced tooth surfaces along a
given line or arc (See Fig 3)
Fig 3 Lead (top) and various pitches (bottom)
32 Axial pitch The pitch of a gear parallel to the axis of rotation
33 Base pitch On an involute gear the base pitch is the pitch on the base circle or
along the line of action It is equal to the circumference of the base circle divided
by the number of teeth
34 Circular Pitch The distance along a specified pitch circle or pitch line between
corresponding profiles of adjacent teeth (See Fig 3)
35 Diametral pitch The diameter of the pitch circle The ratio of the number of
teeth to the pitch diameter in the transverse It is equal to pi divided by the circular
pitch
36 Normal diametral pitch The ration of the number of teeth to the pitch diameter
in the normal plane of a helical gear The normal plane and transverse of a spur
gear are coincident
37 Pitch variation The plus or minus difference in the transverse plane between
the average measured pitch and the actual pitch measurement (See Fig 4)
Fig 4 Pitch Variation
38 Pressure Angle The angle between a tooth profile and a radial line at its pitch
point It is usually equal to 20 degrees
39 Normal pressure angle The angle at a point on the pitch cylinder between the
line of pressure that is normal to the tooth surface and the plane tangent to the pitch
cylinder
40 Profile One side of a tooth in a cross section between the out side circle and
the rootcircle
Fig 5 Profile
41 Functional profile The portion of the tooth flank between the profile control
diameter and the addendum circle or the start of tip round
Fig 6 Functional profile
42 Profile variation The difference between the measured and the specified
functional profile If measured in a normal plane a correction using the appropriate
helix angle must be applied to the measured value
Fig 7 Profile Variation
43 Profile tolerance The permissible amount of profile variation in the functional
profile designated by a specified lsquoKrsquo chart envelope as shown in figure 8 Plus
material at the tip which increases the amount of variation outside the functional
profile is not acceptable Minus material beyond the start of tip can be
disregarded
MEASUREMENT OF GEAR ACCURACY
The methods of testing and measuring gears depend largely on the class of gear
the method of manufacture and the equipment available Because even the
smallest out-of- spec gear can halt operations gear manufacturers have many
inspection options for both functional and analytical evaluation Functional gaging
or ldquoattribute inspectionrdquo offers a quick go or no-go method to check whether a
gear is ldquogoodrdquo or ldquobadrdquo and whether it will function as intended To determine
whether a part meets dimensional specifications gear manufacturers rely on
analytical testing Such analysis is reserved for trouble shooting situations when a
manufacturer is looking for the source of a problem in the gear machining process
The numbers of instrumentation options for both types of dimensional test make
deciding on the correct measurement solution dicey The correct system depends
on the type of gear being measured and the application for which it is intended
Gears with parallel axes are much simpler to gage than those with cross axes and
require a standard rather than customized solution Similarly if a manufacturer is
held to strict tight tolerances on a gear for use in a medical device then accuracy
will determine the choice In terms of application do you want to control your
manufacturing process or inspect a gear to specifications Depending on the
answer yoursquoll need a functional or analytical measurement system
FUNCTIONAL GEAR CHECKING
Functional testing is a qualitative form of inspection to determine whether a gear
will work as intended The most basic form of functional gear test equipment
involves a single-flank or double-flank meshing arrangement between a master
gear and a production gear Another checking methods related to functional
checking is tooth contact or bearing pattern checking Functional or composite gear
checking involves rolling two gears together and measuring the resultant motion
The gears rolled together can be either work and master gears or two work gears
Single-flank configurations display transmission errors of only one flank at a time
Double-flank models display center distance variation and the performance of both
flanks simultaneously Double-flank gear testers expose radial eccentricity or out-
of-round errors but they donrsquot detect angular tooth position defects which can be a
source of transmission errors These testers can find nonsystematic errors
including burrs nicks or hard spots and they enable an inspector to determine
functional tooth thickness
To use a basic functional gear tester the operator mounts a gear on a spindle
brings it to zero backlash mesh and rotates it for one revolution of the production
gear He can then determine center distance variation between the gears Manually
operated systems enable in-process auditing and provide quick visual verification
that the gear falls within specifications
For a test thatrsquos free of operator influence and is faster in analysis throughput
computerized models are a better option Computerized systems can separate
measurements into their finer elements If we want to know just the runout
characteristic of a gear and separate the tooth-to-tooth rolling action we need a
computerized model to do that The computer can separate and give value for
runout tooth-to-tooth and maximum and minimum defects If we try to read those
elements with a dial indicator [a manually operated gear checker] they would flash
so fast that our eyes could never see them
5COMPONENTS OF N-SEREIES GEAR BOX
In our project the following components are involved to achieve the
indefinite speed
1 Structure
2 Flat belt
3 Plummer block
4 Roller
5 Screw rod
6 Ball bearing
7 Handle
51 STRUCTURE
Structural steel is steel construction material a profile formed with a specific
shape or cross section and certain standards of chemical composition and strength
Structural steel shape size composition strength storage etc is regulated in most
industrialized countries
Structural steel members such as I-beams have high second moments of area
which allow them to be very stiff in respect to their cross-sectional area
A steel I-beam in this case used to support wood beams in a house
Structural steel in construction A primed steel beam is holding up the floor above
which consists of a metal deck (Q-Deck) upon which a concrete slab has been
poured
Steel beam through-penetration with incomplete fireproofing
Metal deck and OWSJ (Open Web Steel Joist) receiving first coat of spray
fireproofing plaster made of polystyrene leavened gypsum Contents
1 Common structural shapes
2 Standards
21 Standard structural steels
22 Standard structural steels
221 Carbon steels
222 High strength low alloy steels
223 Corrosion resistant high strength low alloy steels
224 Quenched and tempered alloy steels
3 Steel vs concrete
4 Thermal properties
5 Fireproofing of structural steel
COMMON STRUCTURAL SHAPES
In most developed countries the shapes available are set out in published
standards although a number of specialist and proprietary cross sections are also
available
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB)
and Universal Columns (UC) in Europe it includes the IPE HE HL HD and other
sections in the US it includes Wide Flange (WF) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow
section) and including square rectangular circular (pipe) and elliptical cross
sections)
Angle (L-shaped cross-section)
Channel ( [-shaped cross-section)
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar a piece of metal rectangular cross sectioned (flat) and long but not so wide so
as to be called a sheet
Rod a round or square and long piece of metal or wood see also rebar and dowel
Plate sheet metal thicker than 6 mm or 14 in
Open web steel joist
While many sections are made by hot or cold rolling others are made by welding
together flat or bent plates (for example the largest circular hollow sections are
made from flat plate bent into a circle and seam-welded)
Standard structural steels
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
7 Chordal Thickness The tooth thickness at the pitch line
8 Circular Pitch The distance from the center of one tooth to the center of the next
tooth measured round the circumference of the pitch circle
9 Clearance The amount by which the Dedendum of a gear tooth exceeds the
addendum of a mating gear
10 Center distance The distance from the center of the gear shaft to the center of
the pinion shaft
11 Circular tooth thickness The length of arc between the two sides of the same
gear tooth on a specified circle (Refer figure 1)
12 Datum circle The datum circle is a circle on which measurements are made
13 Composite action test A method of gear inspection in which the work gear is
rolled in tight double-flank contact with a master gear or a specified gear to
determine composite variations
14 Composite tolerance tooth-to-tooth (double-flank) The permissible amount of
tooth-to-tooth composite variation
15 Composite tolerance total (double-flank) The permissible amount of total
composite variation
16 Composite variation Variation in center distance when a gear is inspected by a
composite-action test
17 Composite variation tooth to tooth (double-flank) The greatest change in
center distance while the gear being tested is rotated through any angle of 360degN
during a double flank composite test
18 Total Composite variation (double-flank) The total change in center distance
while the gear being tested is rotated one complete revolution during double-flank
composite-action test
19 Datum of axis rotation The axis of the gear used as the basis for
measurements
20 Datum tooth The designated tooth used as the starting point for measuring
other teeth
21 Diameter profile control The specified diameter of the circle beyond which
the tooth profile must conform to the specified involute curve
22 Dedendum The depth of a tooth space below or inside of the pitch circle
23 Eccentricity The distance between the center of a datum circle and a datum
axis of rotation
24 Face width The length of the gear teeth in an axial plane
25 Functional face width The portion of the face width less the edge round at
each end
26 Index variation The displacement of any tooth from its theoretical position
relative to a datum tooth Measurements are usually linear near the middle of the
functional tooth profile If the measurements are made normal to the tooth surface
they should be corrected to the transverse plane
27 Total Index variation The maximum algebric difference between the extreme
values of index variation for a given gear Total index variation is also equivalent
to total accumulated pitch variation measured by a two probe spacing system
28 Lead The axial advance of a helix for one revolution (see Fig2)
Fig 2 Tooth Thickeness
29 Master gear A gear of known quality that is used to perform a composite-
action test
30 Outside diameter The diameter of the addendum circle (outside) of a
cylindrical gear
31 Pitch The distance between similar equally spaced tooth surfaces along a
given line or arc (See Fig 3)
Fig 3 Lead (top) and various pitches (bottom)
32 Axial pitch The pitch of a gear parallel to the axis of rotation
33 Base pitch On an involute gear the base pitch is the pitch on the base circle or
along the line of action It is equal to the circumference of the base circle divided
by the number of teeth
34 Circular Pitch The distance along a specified pitch circle or pitch line between
corresponding profiles of adjacent teeth (See Fig 3)
35 Diametral pitch The diameter of the pitch circle The ratio of the number of
teeth to the pitch diameter in the transverse It is equal to pi divided by the circular
pitch
36 Normal diametral pitch The ration of the number of teeth to the pitch diameter
in the normal plane of a helical gear The normal plane and transverse of a spur
gear are coincident
37 Pitch variation The plus or minus difference in the transverse plane between
the average measured pitch and the actual pitch measurement (See Fig 4)
Fig 4 Pitch Variation
38 Pressure Angle The angle between a tooth profile and a radial line at its pitch
point It is usually equal to 20 degrees
39 Normal pressure angle The angle at a point on the pitch cylinder between the
line of pressure that is normal to the tooth surface and the plane tangent to the pitch
cylinder
40 Profile One side of a tooth in a cross section between the out side circle and
the rootcircle
Fig 5 Profile
41 Functional profile The portion of the tooth flank between the profile control
diameter and the addendum circle or the start of tip round
Fig 6 Functional profile
42 Profile variation The difference between the measured and the specified
functional profile If measured in a normal plane a correction using the appropriate
helix angle must be applied to the measured value
Fig 7 Profile Variation
43 Profile tolerance The permissible amount of profile variation in the functional
profile designated by a specified lsquoKrsquo chart envelope as shown in figure 8 Plus
material at the tip which increases the amount of variation outside the functional
profile is not acceptable Minus material beyond the start of tip can be
disregarded
MEASUREMENT OF GEAR ACCURACY
The methods of testing and measuring gears depend largely on the class of gear
the method of manufacture and the equipment available Because even the
smallest out-of- spec gear can halt operations gear manufacturers have many
inspection options for both functional and analytical evaluation Functional gaging
or ldquoattribute inspectionrdquo offers a quick go or no-go method to check whether a
gear is ldquogoodrdquo or ldquobadrdquo and whether it will function as intended To determine
whether a part meets dimensional specifications gear manufacturers rely on
analytical testing Such analysis is reserved for trouble shooting situations when a
manufacturer is looking for the source of a problem in the gear machining process
The numbers of instrumentation options for both types of dimensional test make
deciding on the correct measurement solution dicey The correct system depends
on the type of gear being measured and the application for which it is intended
Gears with parallel axes are much simpler to gage than those with cross axes and
require a standard rather than customized solution Similarly if a manufacturer is
held to strict tight tolerances on a gear for use in a medical device then accuracy
will determine the choice In terms of application do you want to control your
manufacturing process or inspect a gear to specifications Depending on the
answer yoursquoll need a functional or analytical measurement system
FUNCTIONAL GEAR CHECKING
Functional testing is a qualitative form of inspection to determine whether a gear
will work as intended The most basic form of functional gear test equipment
involves a single-flank or double-flank meshing arrangement between a master
gear and a production gear Another checking methods related to functional
checking is tooth contact or bearing pattern checking Functional or composite gear
checking involves rolling two gears together and measuring the resultant motion
The gears rolled together can be either work and master gears or two work gears
Single-flank configurations display transmission errors of only one flank at a time
Double-flank models display center distance variation and the performance of both
flanks simultaneously Double-flank gear testers expose radial eccentricity or out-
of-round errors but they donrsquot detect angular tooth position defects which can be a
source of transmission errors These testers can find nonsystematic errors
including burrs nicks or hard spots and they enable an inspector to determine
functional tooth thickness
To use a basic functional gear tester the operator mounts a gear on a spindle
brings it to zero backlash mesh and rotates it for one revolution of the production
gear He can then determine center distance variation between the gears Manually
operated systems enable in-process auditing and provide quick visual verification
that the gear falls within specifications
For a test thatrsquos free of operator influence and is faster in analysis throughput
computerized models are a better option Computerized systems can separate
measurements into their finer elements If we want to know just the runout
characteristic of a gear and separate the tooth-to-tooth rolling action we need a
computerized model to do that The computer can separate and give value for
runout tooth-to-tooth and maximum and minimum defects If we try to read those
elements with a dial indicator [a manually operated gear checker] they would flash
so fast that our eyes could never see them
5COMPONENTS OF N-SEREIES GEAR BOX
In our project the following components are involved to achieve the
indefinite speed
1 Structure
2 Flat belt
3 Plummer block
4 Roller
5 Screw rod
6 Ball bearing
7 Handle
51 STRUCTURE
Structural steel is steel construction material a profile formed with a specific
shape or cross section and certain standards of chemical composition and strength
Structural steel shape size composition strength storage etc is regulated in most
industrialized countries
Structural steel members such as I-beams have high second moments of area
which allow them to be very stiff in respect to their cross-sectional area
A steel I-beam in this case used to support wood beams in a house
Structural steel in construction A primed steel beam is holding up the floor above
which consists of a metal deck (Q-Deck) upon which a concrete slab has been
poured
Steel beam through-penetration with incomplete fireproofing
Metal deck and OWSJ (Open Web Steel Joist) receiving first coat of spray
fireproofing plaster made of polystyrene leavened gypsum Contents
1 Common structural shapes
2 Standards
21 Standard structural steels
22 Standard structural steels
221 Carbon steels
222 High strength low alloy steels
223 Corrosion resistant high strength low alloy steels
224 Quenched and tempered alloy steels
3 Steel vs concrete
4 Thermal properties
5 Fireproofing of structural steel
COMMON STRUCTURAL SHAPES
In most developed countries the shapes available are set out in published
standards although a number of specialist and proprietary cross sections are also
available
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB)
and Universal Columns (UC) in Europe it includes the IPE HE HL HD and other
sections in the US it includes Wide Flange (WF) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow
section) and including square rectangular circular (pipe) and elliptical cross
sections)
Angle (L-shaped cross-section)
Channel ( [-shaped cross-section)
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar a piece of metal rectangular cross sectioned (flat) and long but not so wide so
as to be called a sheet
Rod a round or square and long piece of metal or wood see also rebar and dowel
Plate sheet metal thicker than 6 mm or 14 in
Open web steel joist
While many sections are made by hot or cold rolling others are made by welding
together flat or bent plates (for example the largest circular hollow sections are
made from flat plate bent into a circle and seam-welded)
Standard structural steels
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
18 Total Composite variation (double-flank) The total change in center distance
while the gear being tested is rotated one complete revolution during double-flank
composite-action test
19 Datum of axis rotation The axis of the gear used as the basis for
measurements
20 Datum tooth The designated tooth used as the starting point for measuring
other teeth
21 Diameter profile control The specified diameter of the circle beyond which
the tooth profile must conform to the specified involute curve
22 Dedendum The depth of a tooth space below or inside of the pitch circle
23 Eccentricity The distance between the center of a datum circle and a datum
axis of rotation
24 Face width The length of the gear teeth in an axial plane
25 Functional face width The portion of the face width less the edge round at
each end
26 Index variation The displacement of any tooth from its theoretical position
relative to a datum tooth Measurements are usually linear near the middle of the
functional tooth profile If the measurements are made normal to the tooth surface
they should be corrected to the transverse plane
27 Total Index variation The maximum algebric difference between the extreme
values of index variation for a given gear Total index variation is also equivalent
to total accumulated pitch variation measured by a two probe spacing system
28 Lead The axial advance of a helix for one revolution (see Fig2)
Fig 2 Tooth Thickeness
29 Master gear A gear of known quality that is used to perform a composite-
action test
30 Outside diameter The diameter of the addendum circle (outside) of a
cylindrical gear
31 Pitch The distance between similar equally spaced tooth surfaces along a
given line or arc (See Fig 3)
Fig 3 Lead (top) and various pitches (bottom)
32 Axial pitch The pitch of a gear parallel to the axis of rotation
33 Base pitch On an involute gear the base pitch is the pitch on the base circle or
along the line of action It is equal to the circumference of the base circle divided
by the number of teeth
34 Circular Pitch The distance along a specified pitch circle or pitch line between
corresponding profiles of adjacent teeth (See Fig 3)
35 Diametral pitch The diameter of the pitch circle The ratio of the number of
teeth to the pitch diameter in the transverse It is equal to pi divided by the circular
pitch
36 Normal diametral pitch The ration of the number of teeth to the pitch diameter
in the normal plane of a helical gear The normal plane and transverse of a spur
gear are coincident
37 Pitch variation The plus or minus difference in the transverse plane between
the average measured pitch and the actual pitch measurement (See Fig 4)
Fig 4 Pitch Variation
38 Pressure Angle The angle between a tooth profile and a radial line at its pitch
point It is usually equal to 20 degrees
39 Normal pressure angle The angle at a point on the pitch cylinder between the
line of pressure that is normal to the tooth surface and the plane tangent to the pitch
cylinder
40 Profile One side of a tooth in a cross section between the out side circle and
the rootcircle
Fig 5 Profile
41 Functional profile The portion of the tooth flank between the profile control
diameter and the addendum circle or the start of tip round
Fig 6 Functional profile
42 Profile variation The difference between the measured and the specified
functional profile If measured in a normal plane a correction using the appropriate
helix angle must be applied to the measured value
Fig 7 Profile Variation
43 Profile tolerance The permissible amount of profile variation in the functional
profile designated by a specified lsquoKrsquo chart envelope as shown in figure 8 Plus
material at the tip which increases the amount of variation outside the functional
profile is not acceptable Minus material beyond the start of tip can be
disregarded
MEASUREMENT OF GEAR ACCURACY
The methods of testing and measuring gears depend largely on the class of gear
the method of manufacture and the equipment available Because even the
smallest out-of- spec gear can halt operations gear manufacturers have many
inspection options for both functional and analytical evaluation Functional gaging
or ldquoattribute inspectionrdquo offers a quick go or no-go method to check whether a
gear is ldquogoodrdquo or ldquobadrdquo and whether it will function as intended To determine
whether a part meets dimensional specifications gear manufacturers rely on
analytical testing Such analysis is reserved for trouble shooting situations when a
manufacturer is looking for the source of a problem in the gear machining process
The numbers of instrumentation options for both types of dimensional test make
deciding on the correct measurement solution dicey The correct system depends
on the type of gear being measured and the application for which it is intended
Gears with parallel axes are much simpler to gage than those with cross axes and
require a standard rather than customized solution Similarly if a manufacturer is
held to strict tight tolerances on a gear for use in a medical device then accuracy
will determine the choice In terms of application do you want to control your
manufacturing process or inspect a gear to specifications Depending on the
answer yoursquoll need a functional or analytical measurement system
FUNCTIONAL GEAR CHECKING
Functional testing is a qualitative form of inspection to determine whether a gear
will work as intended The most basic form of functional gear test equipment
involves a single-flank or double-flank meshing arrangement between a master
gear and a production gear Another checking methods related to functional
checking is tooth contact or bearing pattern checking Functional or composite gear
checking involves rolling two gears together and measuring the resultant motion
The gears rolled together can be either work and master gears or two work gears
Single-flank configurations display transmission errors of only one flank at a time
Double-flank models display center distance variation and the performance of both
flanks simultaneously Double-flank gear testers expose radial eccentricity or out-
of-round errors but they donrsquot detect angular tooth position defects which can be a
source of transmission errors These testers can find nonsystematic errors
including burrs nicks or hard spots and they enable an inspector to determine
functional tooth thickness
To use a basic functional gear tester the operator mounts a gear on a spindle
brings it to zero backlash mesh and rotates it for one revolution of the production
gear He can then determine center distance variation between the gears Manually
operated systems enable in-process auditing and provide quick visual verification
that the gear falls within specifications
For a test thatrsquos free of operator influence and is faster in analysis throughput
computerized models are a better option Computerized systems can separate
measurements into their finer elements If we want to know just the runout
characteristic of a gear and separate the tooth-to-tooth rolling action we need a
computerized model to do that The computer can separate and give value for
runout tooth-to-tooth and maximum and minimum defects If we try to read those
elements with a dial indicator [a manually operated gear checker] they would flash
so fast that our eyes could never see them
5COMPONENTS OF N-SEREIES GEAR BOX
In our project the following components are involved to achieve the
indefinite speed
1 Structure
2 Flat belt
3 Plummer block
4 Roller
5 Screw rod
6 Ball bearing
7 Handle
51 STRUCTURE
Structural steel is steel construction material a profile formed with a specific
shape or cross section and certain standards of chemical composition and strength
Structural steel shape size composition strength storage etc is regulated in most
industrialized countries
Structural steel members such as I-beams have high second moments of area
which allow them to be very stiff in respect to their cross-sectional area
A steel I-beam in this case used to support wood beams in a house
Structural steel in construction A primed steel beam is holding up the floor above
which consists of a metal deck (Q-Deck) upon which a concrete slab has been
poured
Steel beam through-penetration with incomplete fireproofing
Metal deck and OWSJ (Open Web Steel Joist) receiving first coat of spray
fireproofing plaster made of polystyrene leavened gypsum Contents
1 Common structural shapes
2 Standards
21 Standard structural steels
22 Standard structural steels
221 Carbon steels
222 High strength low alloy steels
223 Corrosion resistant high strength low alloy steels
224 Quenched and tempered alloy steels
3 Steel vs concrete
4 Thermal properties
5 Fireproofing of structural steel
COMMON STRUCTURAL SHAPES
In most developed countries the shapes available are set out in published
standards although a number of specialist and proprietary cross sections are also
available
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB)
and Universal Columns (UC) in Europe it includes the IPE HE HL HD and other
sections in the US it includes Wide Flange (WF) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow
section) and including square rectangular circular (pipe) and elliptical cross
sections)
Angle (L-shaped cross-section)
Channel ( [-shaped cross-section)
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar a piece of metal rectangular cross sectioned (flat) and long but not so wide so
as to be called a sheet
Rod a round or square and long piece of metal or wood see also rebar and dowel
Plate sheet metal thicker than 6 mm or 14 in
Open web steel joist
While many sections are made by hot or cold rolling others are made by welding
together flat or bent plates (for example the largest circular hollow sections are
made from flat plate bent into a circle and seam-welded)
Standard structural steels
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
Fig 2 Tooth Thickeness
29 Master gear A gear of known quality that is used to perform a composite-
action test
30 Outside diameter The diameter of the addendum circle (outside) of a
cylindrical gear
31 Pitch The distance between similar equally spaced tooth surfaces along a
given line or arc (See Fig 3)
Fig 3 Lead (top) and various pitches (bottom)
32 Axial pitch The pitch of a gear parallel to the axis of rotation
33 Base pitch On an involute gear the base pitch is the pitch on the base circle or
along the line of action It is equal to the circumference of the base circle divided
by the number of teeth
34 Circular Pitch The distance along a specified pitch circle or pitch line between
corresponding profiles of adjacent teeth (See Fig 3)
35 Diametral pitch The diameter of the pitch circle The ratio of the number of
teeth to the pitch diameter in the transverse It is equal to pi divided by the circular
pitch
36 Normal diametral pitch The ration of the number of teeth to the pitch diameter
in the normal plane of a helical gear The normal plane and transverse of a spur
gear are coincident
37 Pitch variation The plus or minus difference in the transverse plane between
the average measured pitch and the actual pitch measurement (See Fig 4)
Fig 4 Pitch Variation
38 Pressure Angle The angle between a tooth profile and a radial line at its pitch
point It is usually equal to 20 degrees
39 Normal pressure angle The angle at a point on the pitch cylinder between the
line of pressure that is normal to the tooth surface and the plane tangent to the pitch
cylinder
40 Profile One side of a tooth in a cross section between the out side circle and
the rootcircle
Fig 5 Profile
41 Functional profile The portion of the tooth flank between the profile control
diameter and the addendum circle or the start of tip round
Fig 6 Functional profile
42 Profile variation The difference between the measured and the specified
functional profile If measured in a normal plane a correction using the appropriate
helix angle must be applied to the measured value
Fig 7 Profile Variation
43 Profile tolerance The permissible amount of profile variation in the functional
profile designated by a specified lsquoKrsquo chart envelope as shown in figure 8 Plus
material at the tip which increases the amount of variation outside the functional
profile is not acceptable Minus material beyond the start of tip can be
disregarded
MEASUREMENT OF GEAR ACCURACY
The methods of testing and measuring gears depend largely on the class of gear
the method of manufacture and the equipment available Because even the
smallest out-of- spec gear can halt operations gear manufacturers have many
inspection options for both functional and analytical evaluation Functional gaging
or ldquoattribute inspectionrdquo offers a quick go or no-go method to check whether a
gear is ldquogoodrdquo or ldquobadrdquo and whether it will function as intended To determine
whether a part meets dimensional specifications gear manufacturers rely on
analytical testing Such analysis is reserved for trouble shooting situations when a
manufacturer is looking for the source of a problem in the gear machining process
The numbers of instrumentation options for both types of dimensional test make
deciding on the correct measurement solution dicey The correct system depends
on the type of gear being measured and the application for which it is intended
Gears with parallel axes are much simpler to gage than those with cross axes and
require a standard rather than customized solution Similarly if a manufacturer is
held to strict tight tolerances on a gear for use in a medical device then accuracy
will determine the choice In terms of application do you want to control your
manufacturing process or inspect a gear to specifications Depending on the
answer yoursquoll need a functional or analytical measurement system
FUNCTIONAL GEAR CHECKING
Functional testing is a qualitative form of inspection to determine whether a gear
will work as intended The most basic form of functional gear test equipment
involves a single-flank or double-flank meshing arrangement between a master
gear and a production gear Another checking methods related to functional
checking is tooth contact or bearing pattern checking Functional or composite gear
checking involves rolling two gears together and measuring the resultant motion
The gears rolled together can be either work and master gears or two work gears
Single-flank configurations display transmission errors of only one flank at a time
Double-flank models display center distance variation and the performance of both
flanks simultaneously Double-flank gear testers expose radial eccentricity or out-
of-round errors but they donrsquot detect angular tooth position defects which can be a
source of transmission errors These testers can find nonsystematic errors
including burrs nicks or hard spots and they enable an inspector to determine
functional tooth thickness
To use a basic functional gear tester the operator mounts a gear on a spindle
brings it to zero backlash mesh and rotates it for one revolution of the production
gear He can then determine center distance variation between the gears Manually
operated systems enable in-process auditing and provide quick visual verification
that the gear falls within specifications
For a test thatrsquos free of operator influence and is faster in analysis throughput
computerized models are a better option Computerized systems can separate
measurements into their finer elements If we want to know just the runout
characteristic of a gear and separate the tooth-to-tooth rolling action we need a
computerized model to do that The computer can separate and give value for
runout tooth-to-tooth and maximum and minimum defects If we try to read those
elements with a dial indicator [a manually operated gear checker] they would flash
so fast that our eyes could never see them
5COMPONENTS OF N-SEREIES GEAR BOX
In our project the following components are involved to achieve the
indefinite speed
1 Structure
2 Flat belt
3 Plummer block
4 Roller
5 Screw rod
6 Ball bearing
7 Handle
51 STRUCTURE
Structural steel is steel construction material a profile formed with a specific
shape or cross section and certain standards of chemical composition and strength
Structural steel shape size composition strength storage etc is regulated in most
industrialized countries
Structural steel members such as I-beams have high second moments of area
which allow them to be very stiff in respect to their cross-sectional area
A steel I-beam in this case used to support wood beams in a house
Structural steel in construction A primed steel beam is holding up the floor above
which consists of a metal deck (Q-Deck) upon which a concrete slab has been
poured
Steel beam through-penetration with incomplete fireproofing
Metal deck and OWSJ (Open Web Steel Joist) receiving first coat of spray
fireproofing plaster made of polystyrene leavened gypsum Contents
1 Common structural shapes
2 Standards
21 Standard structural steels
22 Standard structural steels
221 Carbon steels
222 High strength low alloy steels
223 Corrosion resistant high strength low alloy steels
224 Quenched and tempered alloy steels
3 Steel vs concrete
4 Thermal properties
5 Fireproofing of structural steel
COMMON STRUCTURAL SHAPES
In most developed countries the shapes available are set out in published
standards although a number of specialist and proprietary cross sections are also
available
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB)
and Universal Columns (UC) in Europe it includes the IPE HE HL HD and other
sections in the US it includes Wide Flange (WF) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow
section) and including square rectangular circular (pipe) and elliptical cross
sections)
Angle (L-shaped cross-section)
Channel ( [-shaped cross-section)
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar a piece of metal rectangular cross sectioned (flat) and long but not so wide so
as to be called a sheet
Rod a round or square and long piece of metal or wood see also rebar and dowel
Plate sheet metal thicker than 6 mm or 14 in
Open web steel joist
While many sections are made by hot or cold rolling others are made by welding
together flat or bent plates (for example the largest circular hollow sections are
made from flat plate bent into a circle and seam-welded)
Standard structural steels
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
32 Axial pitch The pitch of a gear parallel to the axis of rotation
33 Base pitch On an involute gear the base pitch is the pitch on the base circle or
along the line of action It is equal to the circumference of the base circle divided
by the number of teeth
34 Circular Pitch The distance along a specified pitch circle or pitch line between
corresponding profiles of adjacent teeth (See Fig 3)
35 Diametral pitch The diameter of the pitch circle The ratio of the number of
teeth to the pitch diameter in the transverse It is equal to pi divided by the circular
pitch
36 Normal diametral pitch The ration of the number of teeth to the pitch diameter
in the normal plane of a helical gear The normal plane and transverse of a spur
gear are coincident
37 Pitch variation The plus or minus difference in the transverse plane between
the average measured pitch and the actual pitch measurement (See Fig 4)
Fig 4 Pitch Variation
38 Pressure Angle The angle between a tooth profile and a radial line at its pitch
point It is usually equal to 20 degrees
39 Normal pressure angle The angle at a point on the pitch cylinder between the
line of pressure that is normal to the tooth surface and the plane tangent to the pitch
cylinder
40 Profile One side of a tooth in a cross section between the out side circle and
the rootcircle
Fig 5 Profile
41 Functional profile The portion of the tooth flank between the profile control
diameter and the addendum circle or the start of tip round
Fig 6 Functional profile
42 Profile variation The difference between the measured and the specified
functional profile If measured in a normal plane a correction using the appropriate
helix angle must be applied to the measured value
Fig 7 Profile Variation
43 Profile tolerance The permissible amount of profile variation in the functional
profile designated by a specified lsquoKrsquo chart envelope as shown in figure 8 Plus
material at the tip which increases the amount of variation outside the functional
profile is not acceptable Minus material beyond the start of tip can be
disregarded
MEASUREMENT OF GEAR ACCURACY
The methods of testing and measuring gears depend largely on the class of gear
the method of manufacture and the equipment available Because even the
smallest out-of- spec gear can halt operations gear manufacturers have many
inspection options for both functional and analytical evaluation Functional gaging
or ldquoattribute inspectionrdquo offers a quick go or no-go method to check whether a
gear is ldquogoodrdquo or ldquobadrdquo and whether it will function as intended To determine
whether a part meets dimensional specifications gear manufacturers rely on
analytical testing Such analysis is reserved for trouble shooting situations when a
manufacturer is looking for the source of a problem in the gear machining process
The numbers of instrumentation options for both types of dimensional test make
deciding on the correct measurement solution dicey The correct system depends
on the type of gear being measured and the application for which it is intended
Gears with parallel axes are much simpler to gage than those with cross axes and
require a standard rather than customized solution Similarly if a manufacturer is
held to strict tight tolerances on a gear for use in a medical device then accuracy
will determine the choice In terms of application do you want to control your
manufacturing process or inspect a gear to specifications Depending on the
answer yoursquoll need a functional or analytical measurement system
FUNCTIONAL GEAR CHECKING
Functional testing is a qualitative form of inspection to determine whether a gear
will work as intended The most basic form of functional gear test equipment
involves a single-flank or double-flank meshing arrangement between a master
gear and a production gear Another checking methods related to functional
checking is tooth contact or bearing pattern checking Functional or composite gear
checking involves rolling two gears together and measuring the resultant motion
The gears rolled together can be either work and master gears or two work gears
Single-flank configurations display transmission errors of only one flank at a time
Double-flank models display center distance variation and the performance of both
flanks simultaneously Double-flank gear testers expose radial eccentricity or out-
of-round errors but they donrsquot detect angular tooth position defects which can be a
source of transmission errors These testers can find nonsystematic errors
including burrs nicks or hard spots and they enable an inspector to determine
functional tooth thickness
To use a basic functional gear tester the operator mounts a gear on a spindle
brings it to zero backlash mesh and rotates it for one revolution of the production
gear He can then determine center distance variation between the gears Manually
operated systems enable in-process auditing and provide quick visual verification
that the gear falls within specifications
For a test thatrsquos free of operator influence and is faster in analysis throughput
computerized models are a better option Computerized systems can separate
measurements into their finer elements If we want to know just the runout
characteristic of a gear and separate the tooth-to-tooth rolling action we need a
computerized model to do that The computer can separate and give value for
runout tooth-to-tooth and maximum and minimum defects If we try to read those
elements with a dial indicator [a manually operated gear checker] they would flash
so fast that our eyes could never see them
5COMPONENTS OF N-SEREIES GEAR BOX
In our project the following components are involved to achieve the
indefinite speed
1 Structure
2 Flat belt
3 Plummer block
4 Roller
5 Screw rod
6 Ball bearing
7 Handle
51 STRUCTURE
Structural steel is steel construction material a profile formed with a specific
shape or cross section and certain standards of chemical composition and strength
Structural steel shape size composition strength storage etc is regulated in most
industrialized countries
Structural steel members such as I-beams have high second moments of area
which allow them to be very stiff in respect to their cross-sectional area
A steel I-beam in this case used to support wood beams in a house
Structural steel in construction A primed steel beam is holding up the floor above
which consists of a metal deck (Q-Deck) upon which a concrete slab has been
poured
Steel beam through-penetration with incomplete fireproofing
Metal deck and OWSJ (Open Web Steel Joist) receiving first coat of spray
fireproofing plaster made of polystyrene leavened gypsum Contents
1 Common structural shapes
2 Standards
21 Standard structural steels
22 Standard structural steels
221 Carbon steels
222 High strength low alloy steels
223 Corrosion resistant high strength low alloy steels
224 Quenched and tempered alloy steels
3 Steel vs concrete
4 Thermal properties
5 Fireproofing of structural steel
COMMON STRUCTURAL SHAPES
In most developed countries the shapes available are set out in published
standards although a number of specialist and proprietary cross sections are also
available
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB)
and Universal Columns (UC) in Europe it includes the IPE HE HL HD and other
sections in the US it includes Wide Flange (WF) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow
section) and including square rectangular circular (pipe) and elliptical cross
sections)
Angle (L-shaped cross-section)
Channel ( [-shaped cross-section)
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar a piece of metal rectangular cross sectioned (flat) and long but not so wide so
as to be called a sheet
Rod a round or square and long piece of metal or wood see also rebar and dowel
Plate sheet metal thicker than 6 mm or 14 in
Open web steel joist
While many sections are made by hot or cold rolling others are made by welding
together flat or bent plates (for example the largest circular hollow sections are
made from flat plate bent into a circle and seam-welded)
Standard structural steels
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
38 Pressure Angle The angle between a tooth profile and a radial line at its pitch
point It is usually equal to 20 degrees
39 Normal pressure angle The angle at a point on the pitch cylinder between the
line of pressure that is normal to the tooth surface and the plane tangent to the pitch
cylinder
40 Profile One side of a tooth in a cross section between the out side circle and
the rootcircle
Fig 5 Profile
41 Functional profile The portion of the tooth flank between the profile control
diameter and the addendum circle or the start of tip round
Fig 6 Functional profile
42 Profile variation The difference between the measured and the specified
functional profile If measured in a normal plane a correction using the appropriate
helix angle must be applied to the measured value
Fig 7 Profile Variation
43 Profile tolerance The permissible amount of profile variation in the functional
profile designated by a specified lsquoKrsquo chart envelope as shown in figure 8 Plus
material at the tip which increases the amount of variation outside the functional
profile is not acceptable Minus material beyond the start of tip can be
disregarded
MEASUREMENT OF GEAR ACCURACY
The methods of testing and measuring gears depend largely on the class of gear
the method of manufacture and the equipment available Because even the
smallest out-of- spec gear can halt operations gear manufacturers have many
inspection options for both functional and analytical evaluation Functional gaging
or ldquoattribute inspectionrdquo offers a quick go or no-go method to check whether a
gear is ldquogoodrdquo or ldquobadrdquo and whether it will function as intended To determine
whether a part meets dimensional specifications gear manufacturers rely on
analytical testing Such analysis is reserved for trouble shooting situations when a
manufacturer is looking for the source of a problem in the gear machining process
The numbers of instrumentation options for both types of dimensional test make
deciding on the correct measurement solution dicey The correct system depends
on the type of gear being measured and the application for which it is intended
Gears with parallel axes are much simpler to gage than those with cross axes and
require a standard rather than customized solution Similarly if a manufacturer is
held to strict tight tolerances on a gear for use in a medical device then accuracy
will determine the choice In terms of application do you want to control your
manufacturing process or inspect a gear to specifications Depending on the
answer yoursquoll need a functional or analytical measurement system
FUNCTIONAL GEAR CHECKING
Functional testing is a qualitative form of inspection to determine whether a gear
will work as intended The most basic form of functional gear test equipment
involves a single-flank or double-flank meshing arrangement between a master
gear and a production gear Another checking methods related to functional
checking is tooth contact or bearing pattern checking Functional or composite gear
checking involves rolling two gears together and measuring the resultant motion
The gears rolled together can be either work and master gears or two work gears
Single-flank configurations display transmission errors of only one flank at a time
Double-flank models display center distance variation and the performance of both
flanks simultaneously Double-flank gear testers expose radial eccentricity or out-
of-round errors but they donrsquot detect angular tooth position defects which can be a
source of transmission errors These testers can find nonsystematic errors
including burrs nicks or hard spots and they enable an inspector to determine
functional tooth thickness
To use a basic functional gear tester the operator mounts a gear on a spindle
brings it to zero backlash mesh and rotates it for one revolution of the production
gear He can then determine center distance variation between the gears Manually
operated systems enable in-process auditing and provide quick visual verification
that the gear falls within specifications
For a test thatrsquos free of operator influence and is faster in analysis throughput
computerized models are a better option Computerized systems can separate
measurements into their finer elements If we want to know just the runout
characteristic of a gear and separate the tooth-to-tooth rolling action we need a
computerized model to do that The computer can separate and give value for
runout tooth-to-tooth and maximum and minimum defects If we try to read those
elements with a dial indicator [a manually operated gear checker] they would flash
so fast that our eyes could never see them
5COMPONENTS OF N-SEREIES GEAR BOX
In our project the following components are involved to achieve the
indefinite speed
1 Structure
2 Flat belt
3 Plummer block
4 Roller
5 Screw rod
6 Ball bearing
7 Handle
51 STRUCTURE
Structural steel is steel construction material a profile formed with a specific
shape or cross section and certain standards of chemical composition and strength
Structural steel shape size composition strength storage etc is regulated in most
industrialized countries
Structural steel members such as I-beams have high second moments of area
which allow them to be very stiff in respect to their cross-sectional area
A steel I-beam in this case used to support wood beams in a house
Structural steel in construction A primed steel beam is holding up the floor above
which consists of a metal deck (Q-Deck) upon which a concrete slab has been
poured
Steel beam through-penetration with incomplete fireproofing
Metal deck and OWSJ (Open Web Steel Joist) receiving first coat of spray
fireproofing plaster made of polystyrene leavened gypsum Contents
1 Common structural shapes
2 Standards
21 Standard structural steels
22 Standard structural steels
221 Carbon steels
222 High strength low alloy steels
223 Corrosion resistant high strength low alloy steels
224 Quenched and tempered alloy steels
3 Steel vs concrete
4 Thermal properties
5 Fireproofing of structural steel
COMMON STRUCTURAL SHAPES
In most developed countries the shapes available are set out in published
standards although a number of specialist and proprietary cross sections are also
available
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB)
and Universal Columns (UC) in Europe it includes the IPE HE HL HD and other
sections in the US it includes Wide Flange (WF) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow
section) and including square rectangular circular (pipe) and elliptical cross
sections)
Angle (L-shaped cross-section)
Channel ( [-shaped cross-section)
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar a piece of metal rectangular cross sectioned (flat) and long but not so wide so
as to be called a sheet
Rod a round or square and long piece of metal or wood see also rebar and dowel
Plate sheet metal thicker than 6 mm or 14 in
Open web steel joist
While many sections are made by hot or cold rolling others are made by welding
together flat or bent plates (for example the largest circular hollow sections are
made from flat plate bent into a circle and seam-welded)
Standard structural steels
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
42 Profile variation The difference between the measured and the specified
functional profile If measured in a normal plane a correction using the appropriate
helix angle must be applied to the measured value
Fig 7 Profile Variation
43 Profile tolerance The permissible amount of profile variation in the functional
profile designated by a specified lsquoKrsquo chart envelope as shown in figure 8 Plus
material at the tip which increases the amount of variation outside the functional
profile is not acceptable Minus material beyond the start of tip can be
disregarded
MEASUREMENT OF GEAR ACCURACY
The methods of testing and measuring gears depend largely on the class of gear
the method of manufacture and the equipment available Because even the
smallest out-of- spec gear can halt operations gear manufacturers have many
inspection options for both functional and analytical evaluation Functional gaging
or ldquoattribute inspectionrdquo offers a quick go or no-go method to check whether a
gear is ldquogoodrdquo or ldquobadrdquo and whether it will function as intended To determine
whether a part meets dimensional specifications gear manufacturers rely on
analytical testing Such analysis is reserved for trouble shooting situations when a
manufacturer is looking for the source of a problem in the gear machining process
The numbers of instrumentation options for both types of dimensional test make
deciding on the correct measurement solution dicey The correct system depends
on the type of gear being measured and the application for which it is intended
Gears with parallel axes are much simpler to gage than those with cross axes and
require a standard rather than customized solution Similarly if a manufacturer is
held to strict tight tolerances on a gear for use in a medical device then accuracy
will determine the choice In terms of application do you want to control your
manufacturing process or inspect a gear to specifications Depending on the
answer yoursquoll need a functional or analytical measurement system
FUNCTIONAL GEAR CHECKING
Functional testing is a qualitative form of inspection to determine whether a gear
will work as intended The most basic form of functional gear test equipment
involves a single-flank or double-flank meshing arrangement between a master
gear and a production gear Another checking methods related to functional
checking is tooth contact or bearing pattern checking Functional or composite gear
checking involves rolling two gears together and measuring the resultant motion
The gears rolled together can be either work and master gears or two work gears
Single-flank configurations display transmission errors of only one flank at a time
Double-flank models display center distance variation and the performance of both
flanks simultaneously Double-flank gear testers expose radial eccentricity or out-
of-round errors but they donrsquot detect angular tooth position defects which can be a
source of transmission errors These testers can find nonsystematic errors
including burrs nicks or hard spots and they enable an inspector to determine
functional tooth thickness
To use a basic functional gear tester the operator mounts a gear on a spindle
brings it to zero backlash mesh and rotates it for one revolution of the production
gear He can then determine center distance variation between the gears Manually
operated systems enable in-process auditing and provide quick visual verification
that the gear falls within specifications
For a test thatrsquos free of operator influence and is faster in analysis throughput
computerized models are a better option Computerized systems can separate
measurements into their finer elements If we want to know just the runout
characteristic of a gear and separate the tooth-to-tooth rolling action we need a
computerized model to do that The computer can separate and give value for
runout tooth-to-tooth and maximum and minimum defects If we try to read those
elements with a dial indicator [a manually operated gear checker] they would flash
so fast that our eyes could never see them
5COMPONENTS OF N-SEREIES GEAR BOX
In our project the following components are involved to achieve the
indefinite speed
1 Structure
2 Flat belt
3 Plummer block
4 Roller
5 Screw rod
6 Ball bearing
7 Handle
51 STRUCTURE
Structural steel is steel construction material a profile formed with a specific
shape or cross section and certain standards of chemical composition and strength
Structural steel shape size composition strength storage etc is regulated in most
industrialized countries
Structural steel members such as I-beams have high second moments of area
which allow them to be very stiff in respect to their cross-sectional area
A steel I-beam in this case used to support wood beams in a house
Structural steel in construction A primed steel beam is holding up the floor above
which consists of a metal deck (Q-Deck) upon which a concrete slab has been
poured
Steel beam through-penetration with incomplete fireproofing
Metal deck and OWSJ (Open Web Steel Joist) receiving first coat of spray
fireproofing plaster made of polystyrene leavened gypsum Contents
1 Common structural shapes
2 Standards
21 Standard structural steels
22 Standard structural steels
221 Carbon steels
222 High strength low alloy steels
223 Corrosion resistant high strength low alloy steels
224 Quenched and tempered alloy steels
3 Steel vs concrete
4 Thermal properties
5 Fireproofing of structural steel
COMMON STRUCTURAL SHAPES
In most developed countries the shapes available are set out in published
standards although a number of specialist and proprietary cross sections are also
available
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB)
and Universal Columns (UC) in Europe it includes the IPE HE HL HD and other
sections in the US it includes Wide Flange (WF) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow
section) and including square rectangular circular (pipe) and elliptical cross
sections)
Angle (L-shaped cross-section)
Channel ( [-shaped cross-section)
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar a piece of metal rectangular cross sectioned (flat) and long but not so wide so
as to be called a sheet
Rod a round or square and long piece of metal or wood see also rebar and dowel
Plate sheet metal thicker than 6 mm or 14 in
Open web steel joist
While many sections are made by hot or cold rolling others are made by welding
together flat or bent plates (for example the largest circular hollow sections are
made from flat plate bent into a circle and seam-welded)
Standard structural steels
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
whether a part meets dimensional specifications gear manufacturers rely on
analytical testing Such analysis is reserved for trouble shooting situations when a
manufacturer is looking for the source of a problem in the gear machining process
The numbers of instrumentation options for both types of dimensional test make
deciding on the correct measurement solution dicey The correct system depends
on the type of gear being measured and the application for which it is intended
Gears with parallel axes are much simpler to gage than those with cross axes and
require a standard rather than customized solution Similarly if a manufacturer is
held to strict tight tolerances on a gear for use in a medical device then accuracy
will determine the choice In terms of application do you want to control your
manufacturing process or inspect a gear to specifications Depending on the
answer yoursquoll need a functional or analytical measurement system
FUNCTIONAL GEAR CHECKING
Functional testing is a qualitative form of inspection to determine whether a gear
will work as intended The most basic form of functional gear test equipment
involves a single-flank or double-flank meshing arrangement between a master
gear and a production gear Another checking methods related to functional
checking is tooth contact or bearing pattern checking Functional or composite gear
checking involves rolling two gears together and measuring the resultant motion
The gears rolled together can be either work and master gears or two work gears
Single-flank configurations display transmission errors of only one flank at a time
Double-flank models display center distance variation and the performance of both
flanks simultaneously Double-flank gear testers expose radial eccentricity or out-
of-round errors but they donrsquot detect angular tooth position defects which can be a
source of transmission errors These testers can find nonsystematic errors
including burrs nicks or hard spots and they enable an inspector to determine
functional tooth thickness
To use a basic functional gear tester the operator mounts a gear on a spindle
brings it to zero backlash mesh and rotates it for one revolution of the production
gear He can then determine center distance variation between the gears Manually
operated systems enable in-process auditing and provide quick visual verification
that the gear falls within specifications
For a test thatrsquos free of operator influence and is faster in analysis throughput
computerized models are a better option Computerized systems can separate
measurements into their finer elements If we want to know just the runout
characteristic of a gear and separate the tooth-to-tooth rolling action we need a
computerized model to do that The computer can separate and give value for
runout tooth-to-tooth and maximum and minimum defects If we try to read those
elements with a dial indicator [a manually operated gear checker] they would flash
so fast that our eyes could never see them
5COMPONENTS OF N-SEREIES GEAR BOX
In our project the following components are involved to achieve the
indefinite speed
1 Structure
2 Flat belt
3 Plummer block
4 Roller
5 Screw rod
6 Ball bearing
7 Handle
51 STRUCTURE
Structural steel is steel construction material a profile formed with a specific
shape or cross section and certain standards of chemical composition and strength
Structural steel shape size composition strength storage etc is regulated in most
industrialized countries
Structural steel members such as I-beams have high second moments of area
which allow them to be very stiff in respect to their cross-sectional area
A steel I-beam in this case used to support wood beams in a house
Structural steel in construction A primed steel beam is holding up the floor above
which consists of a metal deck (Q-Deck) upon which a concrete slab has been
poured
Steel beam through-penetration with incomplete fireproofing
Metal deck and OWSJ (Open Web Steel Joist) receiving first coat of spray
fireproofing plaster made of polystyrene leavened gypsum Contents
1 Common structural shapes
2 Standards
21 Standard structural steels
22 Standard structural steels
221 Carbon steels
222 High strength low alloy steels
223 Corrosion resistant high strength low alloy steels
224 Quenched and tempered alloy steels
3 Steel vs concrete
4 Thermal properties
5 Fireproofing of structural steel
COMMON STRUCTURAL SHAPES
In most developed countries the shapes available are set out in published
standards although a number of specialist and proprietary cross sections are also
available
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB)
and Universal Columns (UC) in Europe it includes the IPE HE HL HD and other
sections in the US it includes Wide Flange (WF) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow
section) and including square rectangular circular (pipe) and elliptical cross
sections)
Angle (L-shaped cross-section)
Channel ( [-shaped cross-section)
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar a piece of metal rectangular cross sectioned (flat) and long but not so wide so
as to be called a sheet
Rod a round or square and long piece of metal or wood see also rebar and dowel
Plate sheet metal thicker than 6 mm or 14 in
Open web steel joist
While many sections are made by hot or cold rolling others are made by welding
together flat or bent plates (for example the largest circular hollow sections are
made from flat plate bent into a circle and seam-welded)
Standard structural steels
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
including burrs nicks or hard spots and they enable an inspector to determine
functional tooth thickness
To use a basic functional gear tester the operator mounts a gear on a spindle
brings it to zero backlash mesh and rotates it for one revolution of the production
gear He can then determine center distance variation between the gears Manually
operated systems enable in-process auditing and provide quick visual verification
that the gear falls within specifications
For a test thatrsquos free of operator influence and is faster in analysis throughput
computerized models are a better option Computerized systems can separate
measurements into their finer elements If we want to know just the runout
characteristic of a gear and separate the tooth-to-tooth rolling action we need a
computerized model to do that The computer can separate and give value for
runout tooth-to-tooth and maximum and minimum defects If we try to read those
elements with a dial indicator [a manually operated gear checker] they would flash
so fast that our eyes could never see them
5COMPONENTS OF N-SEREIES GEAR BOX
In our project the following components are involved to achieve the
indefinite speed
1 Structure
2 Flat belt
3 Plummer block
4 Roller
5 Screw rod
6 Ball bearing
7 Handle
51 STRUCTURE
Structural steel is steel construction material a profile formed with a specific
shape or cross section and certain standards of chemical composition and strength
Structural steel shape size composition strength storage etc is regulated in most
industrialized countries
Structural steel members such as I-beams have high second moments of area
which allow them to be very stiff in respect to their cross-sectional area
A steel I-beam in this case used to support wood beams in a house
Structural steel in construction A primed steel beam is holding up the floor above
which consists of a metal deck (Q-Deck) upon which a concrete slab has been
poured
Steel beam through-penetration with incomplete fireproofing
Metal deck and OWSJ (Open Web Steel Joist) receiving first coat of spray
fireproofing plaster made of polystyrene leavened gypsum Contents
1 Common structural shapes
2 Standards
21 Standard structural steels
22 Standard structural steels
221 Carbon steels
222 High strength low alloy steels
223 Corrosion resistant high strength low alloy steels
224 Quenched and tempered alloy steels
3 Steel vs concrete
4 Thermal properties
5 Fireproofing of structural steel
COMMON STRUCTURAL SHAPES
In most developed countries the shapes available are set out in published
standards although a number of specialist and proprietary cross sections are also
available
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB)
and Universal Columns (UC) in Europe it includes the IPE HE HL HD and other
sections in the US it includes Wide Flange (WF) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow
section) and including square rectangular circular (pipe) and elliptical cross
sections)
Angle (L-shaped cross-section)
Channel ( [-shaped cross-section)
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar a piece of metal rectangular cross sectioned (flat) and long but not so wide so
as to be called a sheet
Rod a round or square and long piece of metal or wood see also rebar and dowel
Plate sheet metal thicker than 6 mm or 14 in
Open web steel joist
While many sections are made by hot or cold rolling others are made by welding
together flat or bent plates (for example the largest circular hollow sections are
made from flat plate bent into a circle and seam-welded)
Standard structural steels
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
5COMPONENTS OF N-SEREIES GEAR BOX
In our project the following components are involved to achieve the
indefinite speed
1 Structure
2 Flat belt
3 Plummer block
4 Roller
5 Screw rod
6 Ball bearing
7 Handle
51 STRUCTURE
Structural steel is steel construction material a profile formed with a specific
shape or cross section and certain standards of chemical composition and strength
Structural steel shape size composition strength storage etc is regulated in most
industrialized countries
Structural steel members such as I-beams have high second moments of area
which allow them to be very stiff in respect to their cross-sectional area
A steel I-beam in this case used to support wood beams in a house
Structural steel in construction A primed steel beam is holding up the floor above
which consists of a metal deck (Q-Deck) upon which a concrete slab has been
poured
Steel beam through-penetration with incomplete fireproofing
Metal deck and OWSJ (Open Web Steel Joist) receiving first coat of spray
fireproofing plaster made of polystyrene leavened gypsum Contents
1 Common structural shapes
2 Standards
21 Standard structural steels
22 Standard structural steels
221 Carbon steels
222 High strength low alloy steels
223 Corrosion resistant high strength low alloy steels
224 Quenched and tempered alloy steels
3 Steel vs concrete
4 Thermal properties
5 Fireproofing of structural steel
COMMON STRUCTURAL SHAPES
In most developed countries the shapes available are set out in published
standards although a number of specialist and proprietary cross sections are also
available
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB)
and Universal Columns (UC) in Europe it includes the IPE HE HL HD and other
sections in the US it includes Wide Flange (WF) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow
section) and including square rectangular circular (pipe) and elliptical cross
sections)
Angle (L-shaped cross-section)
Channel ( [-shaped cross-section)
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar a piece of metal rectangular cross sectioned (flat) and long but not so wide so
as to be called a sheet
Rod a round or square and long piece of metal or wood see also rebar and dowel
Plate sheet metal thicker than 6 mm or 14 in
Open web steel joist
While many sections are made by hot or cold rolling others are made by welding
together flat or bent plates (for example the largest circular hollow sections are
made from flat plate bent into a circle and seam-welded)
Standard structural steels
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
Structural steel in construction A primed steel beam is holding up the floor above
which consists of a metal deck (Q-Deck) upon which a concrete slab has been
poured
Steel beam through-penetration with incomplete fireproofing
Metal deck and OWSJ (Open Web Steel Joist) receiving first coat of spray
fireproofing plaster made of polystyrene leavened gypsum Contents
1 Common structural shapes
2 Standards
21 Standard structural steels
22 Standard structural steels
221 Carbon steels
222 High strength low alloy steels
223 Corrosion resistant high strength low alloy steels
224 Quenched and tempered alloy steels
3 Steel vs concrete
4 Thermal properties
5 Fireproofing of structural steel
COMMON STRUCTURAL SHAPES
In most developed countries the shapes available are set out in published
standards although a number of specialist and proprietary cross sections are also
available
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB)
and Universal Columns (UC) in Europe it includes the IPE HE HL HD and other
sections in the US it includes Wide Flange (WF) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow
section) and including square rectangular circular (pipe) and elliptical cross
sections)
Angle (L-shaped cross-section)
Channel ( [-shaped cross-section)
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar a piece of metal rectangular cross sectioned (flat) and long but not so wide so
as to be called a sheet
Rod a round or square and long piece of metal or wood see also rebar and dowel
Plate sheet metal thicker than 6 mm or 14 in
Open web steel joist
While many sections are made by hot or cold rolling others are made by welding
together flat or bent plates (for example the largest circular hollow sections are
made from flat plate bent into a circle and seam-welded)
Standard structural steels
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
I-beam (I-shaped cross-section - in Britain these include Universal Beams (UB)
and Universal Columns (UC) in Europe it includes the IPE HE HL HD and other
sections in the US it includes Wide Flange (WF) and H sections)
Z-Shape (half a flange in opposite directions)
HSS-Shape (Hollow structural section also known as SHS (structural hollow
section) and including square rectangular circular (pipe) and elliptical cross
sections)
Angle (L-shaped cross-section)
Channel ( [-shaped cross-section)
Tee (T-shaped cross-section)
Rail profile (asymmetrical I-beam)
Railway rail
Vignoles rail
Flanged T rail
Grooved rail
Bar a piece of metal rectangular cross sectioned (flat) and long but not so wide so
as to be called a sheet
Rod a round or square and long piece of metal or wood see also rebar and dowel
Plate sheet metal thicker than 6 mm or 14 in
Open web steel joist
While many sections are made by hot or cold rolling others are made by welding
together flat or bent plates (for example the largest circular hollow sections are
made from flat plate bent into a circle and seam-welded)
Standard structural steels
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
Most steels used throughout Europe are specified to comply with the European
standard EN 10025 However many national standards also remain in force
Typical grades are described as S275J2 or S355K2W In these examples S
denotes structural rather than engineering steel 275 or 355 denotes the yield
strength in newtons per square millimetre or the equivalent megapascals J2 or K2
denotes the materials toughness by reference to Charpy impact test values and the
W denotes weathering steel Further letters can be used to designate normalized
steel (N or NL) quenched and tempered steel (Q or QL) and thermo
mechanically rolled steel (M or ML)
The normal yield strength grades available are 195 235 275 355 420 and 460
although some grades are more commonly used than others eg in the UK almost
all structural steel is grades S275 and S355 Higher grades are available in
quenched and tempered material (500 550 620 690 890 and 960 - although
grades above 690 receive little if any use in construction at present)
]Thermal properties
The properties of steel vary widely depending on its alloying elements
The austenizing temperature the temperature where a steel transforms to an
austenite crystal structure for steel starts at 900degC for pure iron then as more
carbon is added the temperature falls to a minimum 724degC for eutectic steel (steel
with only 83 by weight of carbon in it) As 21 carbon (by mass) is
approached the austenizing temperature climbs back up to 1130degC Similarly the
melting point of steel changes based on the alloy
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
The lowest temperature at which a plain carbon steel can begin to melt its solidus
is 1130 degC Steel never turns into a liquid below this temperature Pure Iron (Steel
with 0 Carbon) starts to melt at 1492 degC (2720 degF) and is completely liquid upon
reaching 1539 degC (2802 degF) Steel with 21 Carbon by weight begins melting at
1130 degC (2066 degF) and is completely molten upon reaching 1315 degC (2400 degF)
Steel with more than 21 Carbon is no longer Steel but is known as Cast iron
httpwwwmsmcamacukphase-transimagesFeCgif
]Fireproofing of structural steel
In order for a fireproofing product to qualify for a certification listing of structural
steel through a fire test the critical temperature is set by the national standard
which governs the test In Japan this is below 400degC In China Europe and North
America it is set at ca 540degC The time it takes for the steel element that is being
tested to reach the temperature set by the national standard determines the duration
of the fire-resistance rating
Care must be taken to ensure that thermal expansion of structural elements does
not damage fire-resistance rated wall and floor assemblies Penetrants in a firewalls
and ferrous cable trays in organic firestops should be installed in accordance with
an appropriate certification listing that complies with the local building code
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
52 INTRODUCTION OF FLAT BELT DRIVE
Definition
The power or energy produced in one machine can be transmitted to another
machine or between two members of a machine by means of some intermediate
mechanisms called drives
Classification of Flat belt drives
Depending upon the use the flat belt drives are classified into the following
categories
1) Open belt drive
In this type the shafts of driving and driven members are kept parallel and the
direction of rotations of both pulleys are same The line joining the centres of
pulleys
may be horizontal vertical or inclined
Open Belt Drive
2) Cross or twist belt drive
Here the shafts are kept parallel but the directions of rotations of pulleys are
opposite to
each other
(3) Quarter-turn drive
In this case the axes of pulleys are arranged at right angles to each other The drive
is
sometimes provided with an idler pulley so as to maintain the required arc of
contact
(4) Belt drive with an idler pulley
Here a small extra pulley is operated in the slack side of the belt drive apart from
the
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
usual pulleys (ie driving and driven pulleys) for increasing the arc of contact and
thus
the power transmission is properly maintained
(5) Belt drives with many pulleys
Here many pulleys are operated by a single belt so that many operations are carried
out at
a time
DESIGN OF FLAT BELTS
The essential parameters of flat belt like width thickness length and the type
of belt are determined based on two methods
1 Using Fundamental formulas
2 Using Manufacturers catalogs
1 Using fundamental formulas
Oslash When the driving pulley rotates the driven pulley by belt the belt pulling side is
known as tight side and the belt releasing side is known as slack side
Oslash If the centre distance and the selected materials of belt and pulleys are kept
proper the belts can have sufficient grip over the pulley without any slip and the
power transmission is properly maintained
Oslash For designing the belt based on fundamental formulae we should know the
tensions (ie loads) on tight side and slack side of the pulleys power-torque
relationship coefficient of friction between the contact surfaces of pulleys and
belt diameters of pulleys and so on
Design of belts by this method is based mainly on two concepts
1 How much power (ie Maximum power (or) Design power) to be transmitted
2 What may be the power transmitting capacity (ie belt rating) of the selected
belt
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
Arc of contact
Consider the driving pulley and the driven pulley are connected by a flat belt as
shown in
fig The angle subtended by the overlaying belt on the pulley is known as angle of
contact
or arc of contact (1049113)
Let d = Diameter of smaller pulley
D = Diameter of bigger pulley
C = Centre distance between pulleys
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
53 PLUMMER BLOCK
Early pillow-block with bearing A pillow block also known as a plumber
block[1] or bearing housing is a mounted plain or roller bearing used to provide
support for a rotating shaft with the mounting surface on a parallel line with the
axis of the shaft Housing material for a pillow block is typically made of cast iron
or pressed steel Pillow blocks are extensively used in conveyor systems such as
tube chain conveyors Pillow blocks are usually referred to the housings which
have a bearing fitted into them amp thus the user need not purchase the bearings
separately Pillow blocks are usually mounted in cleaner environments amp generally
are meant for lesser loads of general industry These differ from plummer blocks
which are bearing housings supplied without any bearings amp are usually meant for
higher load ratings amp corrosive industrial environments
However fundamental application of both types is the same which is to primarily
mount bearings safely enabling their outer ring to be stationary usually and
allowing rotation of the inner ring The housing is bolted to a foundation through
the holes in the base Bearing housings are either split type or unsplit type Split
type housings are usually two piece housings where the cap and base can be
detached While certain series are one single piece housings Various seals are
provided to prevent dust and other contaminants from entering the housing Thus
the housing provides a clean environment for the expensive bearings to freely
rotate hence increasing their performance and duty cycle
Large bearing housings are usually made of grey cast iron However various
different grades of metals can be used to manufacture the same Small and low-
cost housings are die-cast in zinc or aluminium alloys
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
54 BEARINGSINTRODUCTION
Bearing is a stationery machine element which supports a rotating shafts or axles
and
confines its motion Naturally a bearing will be required to offer minimum
frictional
resistance to moving parts so as to result in minimum loss of power In order to
reduce frictional resistance a layer of fluid may be provided
CLASSIFICATION OF BEARING
Bearings are mainly classified as follows
(i) Depending upon the type of load coming upon the shaft
In radial bearings the load acts perpendicular to the direction of
Of moving parts (ie Shaft) It is shown in fig 441
A) Radial bearing
B) Thrust bearings
In thrust bearings the pressure acts along or parallel to the axis of the shaft
(iii) Depending upon the nature of contact
A) Sliding contact
B) Rolling contact bearings or Antifriction bearings
In sliding contact bearings the shaft rotates in a bearing and there are no
interposed
elements between shaft and bearings There is a direct contact between shaft and
bearings
In rolling contact bearings the steel balls or rollers are provided in between shaft
and
bearings to reduce friction
BEARING MATERIALS
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
Bearing material should have the following properties
I) High compressive strength
Ii) Low coefficient of friction
Iii) High thermal conductivity
Iv) High resistance to corrosion
V) Sufficient fatigue strength
Vi) It should be soft with a low modulus of elasticity
Vii) Bearing materials should not get weld easily to the journal material
(i) Lead base contains
It contains Lead-74 Antimony- 15 Tin- 1 Arsenic-O 5 and Cu-O25
It has excellent resistance to seizure and has good corrosion resistance its
compressive strength and hardness decrease rapidly with an increase in
temperature
Therefore it should not be used above 1150
It is used for split bushings made from strip or gravity cast bearings
(U) Tin base habit
It contains Tin-89 Antimony-75 and Copper-325
It is slightly harder than lead habit at room temperature It has excellent anti-series
deformability and acid-resisting properties It is also
Used for split bushings
(iii) Leaded bronze
The compositions and use of leaded bronze are as follows
Cu 80 Tin 10 Lead-l0 it used for split bushings made 4
From strip or gravity cast bears 4
These are having excellent Fatigue life and are capable of Carrying heavy loads at
high Temperatures
Cu-72 Tin-3 Lead-23 Use for split bushings and hailrsquo
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
Beings made from strip or Gravity cast bearings
(iv) Copper lead alloy
The compositions and uses of copper lead alloy are as follows Cu-65 Lead 35
Use for split bushings and half Bearings made from strip or Gravity cast bearings
Cu-71 Lead-28 Silver-l Used for gravity cast bearings these are having
excellent fatigue life and capable of carrying heavy leads at high temperatures But
they are having poor erosion resistance compared to Habit
(v) Gun metal
Its composition is as follows
Copper-88 Tin-l0 Zinc-2
It is used for high-grade bearings subjected to high pressure and high speeds
(vi) Phosphor bronze
Superior fatigue resistance
(x) Plastics
Composition is Copper-80 Tin- 10 Lcad-9 Phosphores- 1 It is used for
bearings subjected to very high pressures and speeds
(vii) Cast Iron
It is used with steel journals It should be provided with adequate lubricant It is
used for low pressure and low speed bearings
(viii) Aluminum alloy
Its composition is Al-92 Cu-l Tin-6 Ni-1
It is used for cast or forged solid construction It has better fatigue resistance but
poor surface behavior
(ix) Silver
The usual form of construction is clectro- plated bearing used with lead-tin or
leadindium overlay It has excellent corrosion resistance and
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
The common commercial plastics used for bearings are Nylon and Teflon These
may be used as zero film bearings These have high fatigue strength hardness and
more resistant to abrasive wear
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
55 SCREW ROD
SCREW THREAD MEASUREMENT
v Screw threads are used to transmit the power and motion and also used to fasten
two components with the help of nuts bolts and studs
v There is a large variety of screw threads varying in their form by included angle
head angle helix angle etc
v The screw threads are mainly classified into 1) External thread 2) Internal thread
External thread
Internal thread
SCREW THREAD TERMINOLOGY
1) Screw thread
It is a continuous helical groove of specified cross-section produced on the external
or internal surface
2) Crest
It is top surface joining the two sides of thread
3) Flank
Surface between crest and root
4) Root
The bottom of the groove between the two flanks of the thread
5 Lead
Lead = number starts x pitch
6) Pitch
The distance measured parallel to the axis from a point on a thread to the
corresponding
next point
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
7) Helix angle
The helix is the angle made by the helix of the thread at the pitch line with the axis
8) Flank angle
Angle made by the flank of a thread with the perpendicular to the thread axis
9) Depth of thread
The distance between the crest and root of the thread
10) Included angle
Angle included between the flanks of a thread measured in an axial plane
11) Major diameter
Diameter of an imaginary co-axial cylinder which would touch the crests of
external or
internal thread
12) Minor diameter (Root diameter or Core diameter)
Diameter of an imaginary co-axial cylinder which would touch the roots of an
external
thread
13)Addendum
Oslash Radial distance between the major and pitch cylinders For external thread
Oslash Radial distance between the minor and pitch cylinder For internal thread
14) Dedendum
v Radial distance between the pitch and minor cylinder = For external thread
v Radial distance between the major and pitch cylinders = For internal thread
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
THREAD DATA
SNO Forms of
thread
Shape of
thread
Angle
between flankes
in deg
Application
1 British
standard
whitworth
BSW
Symmetrical
V
55 Bolt and screw and
fatening parts
subjected to vibration
in aero and auto
parts
2 British
association
thread BA
Symmetrical
V
475 Instruments and
precision works
3 American
national
standard
thread
Symmetrical
V with flat
crest and
root
60 General purpose
Example bolts nuts
screw and tapped
holes
4 Unified
standard
thread
Symmetrical
V with
rounded
crest and
root
60 Used in Brittan Canada and
US
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
5 Square
thread
Square Perpendicular to
axis of thread
Power transmission
used in machine tools
valves spindle and
screw jack
6 Acme thread Modified
form of
Square
thread
29 Screw
cuttinglathesbrass
valves cocks and
bench vices
7 Knuckle
thread
Rounded top
and bottom
- Rail way carriage
couplings hydrants
neck of class bottles
8 Butters
thread
Both square
and V
45 Spindles of bench
vices
9 Metric
thread
Similar to
BSW thread
60 Fastening application
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
6DESIGN ASPECTS AND OPERATION
PROPERTIES OF MILD STEEL
PHYSICAL PROPERTY
Density - 7860 Kgm3
Melting point - 1427c
Thermal conductivity - 63 W m K
CARBON CONTENT
Low Carbon (or) Mild steel - 015 to045 carbon
MECHANICAL PROPERTY
Elasticity
Ductility
Toughness
Weld ability
In our design screw type clamp Body of jig have a main part hence the
calculations are concentrated on it
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
OPERATIONS INVOLVED
Turning (facing plain turning step turning threading etc)
Facing (flat surface)
Drilling
Gas cutting (flat plate cylindrical rods)
Shaping
Welding
Tapping
Thread cutting
TURNING
Turning is the operation of reducing a cylindrical surface by removing
material from the outside diameter of a work piece It is done by rotating the work
piece about the lathe axis and feeding the tool parallel to the lathe axis Due to this
operation screw rod and head are done by the turning operation to get the required
shape
FACING
Machining the end of the work piece to produce flat surface is called facing
Due to this the plate can get flat surface have done by the facing operation
DRILLING
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
Drilling is the operation of producing cylindrical hole in work piece It is
done by rotating the cutting edge of the cutter known as drill bit In this
Project the jig plates require holes for locating indexing plate and screw rod drill
bush assembly These holes are done by conventional vertical drilling machine
THREAD CUTTING
Thread cutting is the operation of forming external thread of required
diameter of rod by using a multipoint tool is called thread This process is used in
screw clamp to done on the rod which is used for the movement of the movable
plate
Fine grinding
It is nothing but the grinding process which is done as smooth
with fine grains This is done as the each plate and base plate for good surface
finish It is done by conventional grinding machine
Gas cutting It is used to break are cut the plates In this project it is used
to cut the raw materials such as plates This done by gas cutting machine
Shaping
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
Shaping operation is used to reduce the dimensions of the
plates In this project the plates are in need of shaping process It is
done by shaping machine
Welding
It is the process which is used to join two is more similar
materials as well as dissimilar materials In this project it is used to
join the jig plate one to another This is done by arc welding
machine
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
7 ADVANTAGES AND APPLICATIONS
ADVANTAGES
It is used for to achieve different speed by simple mechanism
Its operation and maintenance is very simple
It is compact and portable
It is simple and rigid in construction
Manufacturing cost is lesser than other gear boxes
It provides better speed changes method on the driving unit
52 APPLICATIONS
This device find place in almost all types of industries (Large Small medium
scale industries)
This device is mainly used in wherever different speed need
This device is suitable for fine speed changes aswellas to achieve
rapid speed changes
71 PROCESS CHART
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
Part name Operations Machine used Materials used
1Stucture
The MS plate of rough size is
cut drilled amp shaped to finish
size
Gas cutting mc Drilling mc
Mild steel
2Plummerblock
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
3Bearings
The MS square of rough size
is cut drilled amp shaped to
finish size
-
Mild steel
4screw rod
The MS rod is turned faced
threaded amp drilled to require
diameter
Lathe Drillingamp Threading mc
Mild steel
5 Roller
The round log is cut to
require size drilled taper
turnedto required dia amp
shaped to finish size
Drilling mc Turning Rose wood
6Equaliser plate
The MS square is cut to
require size drilled to
required dia amp shaped to
finish size
Gas cutting mcShaping mc Drilling mc
Mild steel
For assembling of parts welding has been done where ever necessary
72 Design process
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
PRIMARY CUTTING PROCESS
The processes used for preliminary cutting of the component are known as
primary cutting process The common operations involved in this process are gas
cutting sawing etc
MACHINING PROCESS
The process used for giving final shape to the component according to the
planned dimension is known as machining process The common processes
involved in this process are turning planning shaping drilling etc
SURFACE FINISHING PROCESS
The process used to provide a good surface finish for the components are
called as surface finishing process The common operations used for this process
are polishing buffing abrasive belt grinding super finishing etc
JOINING PROCESS
The processes used to join the components are known as joining process
The common operations used for this process are welding riveting screw
fastening drilling etc
73 GENERAL PROCEDURE OF DESIGN
REGOGANISATION OF NEED
First make a complete statement of the problem indicating the need aim
or purpose for which is to be designed
SYNTHESIS (MECHANISM)
Select the possible mechanism or group of mechanism which will give the
desired motion
ANALYSIS OF FORCES
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
Find the forces acting on the each member of the machine and energy
transmitted by the each member
MATERIAL SELECTION
Select the material best suited for each member of the machine
DESIGN OF ELEMENTS (SIZE AND STRESSES)
Find the size of each member of the machine by considering the forces acting
on the member and the permissible stress for the material used It should be kept in
the mind that each member should not deflect or deform then the permissible limit
MODIFICATION
Modify the size of the member to agree with the past experience and
judgment to facilitate manufacture The modification may also be necessary by
consideration of manufacturing to reduce overall cost
DETAILED DRAWING
Draw the detailed drawing of each component of each assembly of the
machine with complete specification for the manufacturing process suggested
PRODUCTION
The component as per the drawing is manufactured in the workshop
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
8COST ESTIMATION
SNO Name of the part Weight in kg Cost RS
1Structure 7 680
2roller 2 760
3Plmmer block 2 375
4Screw rod 1 250
5M16 screw rod frac34 100
6 Bearing 2 150
7 Handle 1 175
TOTAL = 249000
LABOUR COST
Lathe drilling shaping welding riveting turning painting surface grinding
and gas cutting
Cost = Rs 180000
102 TOTAL COST
Total cost = material cost + Labour cost
= 2490 + 1800
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
= 429000
Total cost for this project = Rs 429000
9DIAGRAM OF N-SERIES GEAR BOX
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
CONCLUSION
This report details with design of Nseries gear box is attached with the
Part drawings The project carried out by us made an impressing task in the
Manufacturing works It is very useful for the speed controlling areasThis project
has been designed to perform the entire requirement task which has also been
provided
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
BIBLOGRAPHY
1 Jig and fixture design by EDWARDGHOFFMAN
2 Jigs and fixtures by PHJOSHI
3 Work shop technology by RS KHURMI
4 Engineering practice by RK NATARAJAN
5 Machine tools (vol2) by SK HAJRA CHOUDRY
6 Design data by PSG COLLEGE OF TECHNOLOGY
- 1PROJECT PLANING
-
- PROJECT CAPACITY
- DRAWINGS
- MATERIAL EQUIPMENT
- MACHINE LODING
- PURCHASE CONSIDERATION
- EQUIPMENT CONSIDERATION
- COST CALCULATION
- COMPARION
- REPORT
-
- For assembling of parts welding has been done where ever necessary
- 72 Design process
- PRIMARY CUTTING PROCESS
- SURFACE FINISHING PROCESS
- JOINING PROCESS
- REGOGANISATION OF NEED
- SYNTHESIS (MECHANISM)
- ANALYSIS OF FORCES
- MATERIAL SELECTION
- Select the material best suited for each member of the machine
- DESIGN OF ELEMENTS (SIZE AND STRESSES)
- MODIFICATION
- DETAILED DRAWING
- The component as per the drawing is manufactured in the workshop
- 8COST ESTIMATION
- TOTAL = 249000
- LABOUR COST
- Total cost for this project = Rs 429000
- This report details with design of Nseries gear box is attached with the
-
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