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DESIGN OF HYDRUALIC RAIL CAR MOVER
Submitted in partial fulfilment of the requirements
For the degree of
Bachelor of Engineering
In
Mechanical Engineering
By
Chakravarti Atole
Avinash Bagul
Deepak Khabale
Shalom Varghese
Guide
Prof. Ashok Patole
Department of Mechanical Engineering
MES‟s Pillai‟s Institute of Information Technology, Engineering,
Media Studies and Research,
New Panvel, Navi Mumbai 410 206
2011-12
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Department of Mechanical Engineering
MES’s Pillai’s Institute of Information Technology,
Engineering, Media Studies & Research
New Panvel – 410 206
Certificate
This is to certify that the requirement for the project entitled „Design of Hydraulic Rail Car
Mover‟ has been carried out by
Name Roll No.
Chakravarti Ramesh Atole 802
Avinash Devidas Bagul 804
Deepak Tanaji Khabale 824
Shalom Sunny Varghese 867
In the partial fulfillment for the award of degree in Mechanical Engineering for Mumbai
University in the academic year 2011-2012.
Prof. Ashok Patole Mr. S. K. Sayyad
(Internal guide) (External Guide)
Prof. Sandeep Joshi Dr. R. I. K. Moorthy
(Head of Department) (Principal)
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REPORT APPROVAL SHEET FOR B.E. PROJECT
The Project report entitled “Design of Hydraulic Rail Car Mover” (Chakravarti Atole (802),
Avinash Bagul (804), Deepak Khabale (824), and Shalom Varghese (867)) is approved for the
partial fulfillment of the award of the degree of Bachelor of Mechanical Engineering.
(Prof. Sandeep Joshi) (Prof. Ashok Patole)
HEAD GUIDE
Department of Mechanical Engineering Department of Mechanical Engineering
M E S’s Pillai’s Institute of Information Technology, Engineering, Media Studies and
Research, New Panvel, Navi Mumbai 410 206
EXAMINERS
1) ---------------------------------------------
2) ----------------------------------------------
Principal
M E S’s Pillai’s Institute of Information Technology,
Engineering, Media Studies and Research,
New Panvel, Navi Mumbai 410 206
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ABSTRACT
Indian Railways is one of the largest railway networks in the world. It operates both
long distance and suburban rail systems. Indian railway workshop at Matunga carries out
Periodical Overhaul (POH) and heavy corrosion repairs of main line as well as EMU coaches.
The Yard engine, Traverser, overhead cranes are used to move the coaches from one place to
another. These means have their own advantages and disadvantages.
Overall these systems are bulky requires proper maintenance, electricity consumptions
is high, operations are noisy and requires more than one person to do task, workers attention
is needed for safety. The time required for shunting operation is more.
Hydraulic rail car mover can be use for better, efficient and safe work at workshop,
requires no major alterations in the workshop for installation. The rail car mover can provide
higher productivity because the person controlling the movements stands next to where work
is being done, making it easy to position cars right where they need to be.
The design of Hydraulic rail car mover includes design of hydraulic cylinder, dog arm,
bearing and the modeling of parts using CAD Software and analysis of Hydraulic rail car
mover components.
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CONTENTS
Chapter Title Page
ABSTRACT i LIST OF FIGURES iv LIST OF TABLES vi NOMENCLATURE
ACKNOWLEDGEMENT
v
vii
1 INTRODUCTION 1 1.1 Background 1
1.2 Aim and Objectives 5
1.3 Report Layout 6
2 LITERATURE REVIEW 7 2.1 Introduction to Hydraulics 8
2.2 Rephasing Cylinder System 9
2.3 Trends in Hydraulics 10
2.4 Computer Application in Hydraulics 11
3 DESIGN AND CALCULATIONS 13 3.1 Introduction 13
3.2 Operation of The System 14
3.3 Operation of Direction control Check Valve 16
3.4 Calculations of Hydraulic Rail Car Mover 28
3.5 Design of Roller Bearing 21
3.6 Justification of Assumptions 23
4 MODELLING USING PRO ENGINEER 24 4.1 Introduction 24
4.2 Hydraulic cylinder Model 25
4.3 Models of parts of Hydraulic Cylinder 25
4.4 Cross section of Hydraulic Cylinder 27
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Chapter Title Page
5 ANALYSIS OF ARM USIGN PATRAN/NASTRAN 28
5.1 Introduction 28
5.2 Design of Arm 29
5.3 Results 31
6 CONCLUSION AND FUTURE SCOPE 32
7 REFERENCES 33
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LIST OF FIGURES
Figure Title Page
1.1 Layout of carriage workshop Matunga 1
1.2 Value Stream Mapping of workshop activities 2
1.3 Cause Effect Diagram 4
2.1 Hydraulic power equipment trends 7
2.2 Hydraulic System Design and Analysis Process 10
2.3 Graph of Modeling and simulation trends 11
3.1 Axle dog model 13
3.2 Operational Sequence Schematic Representation 14
3.3 Schematic of Cylinder 15
3.4 Check valve diagram 16
4.1 Hydraulic cylinder Assembly model 25
4.2 Model of Front end and Back end 25
4.3 Model of Piston and piston rod 26
4.4 Model of Piston rod end 26
4.5 Cross section of Front part of cylinder 27
4.6 Cross section of Rear part of cylinder 27
5.1 Steps in Analysis 28
5.2 Model of Axle dog arm 30
5.3 Meshing and Load applied using Patran 30
5.4 Result constraint forces 31
5.5 Result stress and Displacement 31
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LIST OF TABLES
Table Title Page
1.1 Symbols of Value stream map 2
3.1 Cost of Hydraulic rail car mover 23
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NOMENCLATURE
D Cylinder bore diameter, m
L Length of cylinder, m
dpr Piston rod diameter, m
d Piston inner tube diameter, m
l Length of piston rod, m
dp Pass tube diameter, m
lp Length of pass tube, m
da Axle dog cylinder bore diameter, m
la Length of Axle dog cylinder, m
F Force, kN
P Power, kW
Q Flow rate, m3/sec
H Pressure head, m
g Acceleration due to gravity, m/s2
C Dynamic capacity, kgf
Peq Equivalent load, N
Greek
η Efficiency, %
ρoil Density of oil, kg/m3
Subscripts
pr Piston rod
p Pass tube
a Axle dog
r Radial load
a Axial load
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ACKNOWLEDGEMENT
We would like to use this medium to express our sincere feelings of gratitude to all
those people who have selflessly taken pains to make this project training part successful at
Carriage workshop, Central railway, Matunga. It is very worthwhile and value added
experience take this opportunity to express our gratitude to all the individual whose
contribution have helped us in undergoing training.
First of all I would like to thank Mr. A. R. TUPE (C.W.M.), Mr. M. K. KAREKAR
(A.P.L.E. training officer) and Mr. C. SHETTY (C.I, B.T.C.) for giving me an opportunity
to take training in this historic workshop.
I express my heartily gratitude to Mr. S. K. SAYYED ( Jr. Inst, B.T.C.), Mr. RANE
(Sr. Inst, B.T.C. ) and Mr. P. PATIL (D.V.) for their unstinting support and suggestions
which gave me direction to work.
Special thanks to Prof. ASHOK PATOLE (Internal guide), Dr. R. I. K.
MOORTHY (Principal, PIIT) and Prof. SANDEEP JOSHI (HOD, Mechanical Dept.),
Prof. M. D. NADAR (Project In-charge) for all their support and suggestions and
invaluable guidance.
We would also like to thank all Railway workshop officials, shop superintendents and
PIIT Professors, Staff members and faculty members of Mechanical Department for
invaluable help at all the time.
Last but not the least we would like to thank all my colleagues and workers of railway
workshop for all the co-operation and for their direct and indirect help during the phase of
project training.
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CHAPTER 1
INTRODUCTION
Indian Central Railway is the leading passenger carrying system. It carries more than 4
lacs passengers every day to each nook and corner of the country through Mail/Express
/Passenger trains. Mumbai Suburban Train System is the life line of the Metropolitan
City. More than 3 million passenger travel every day in 1573 suburban trains, moving across
77 stations.
The Carriage Workshop, Matunga covers a triangular piece of land/area of 35
hectares, including a covered area of about 11 hectares. There are 23 mechanical sections and
7 electrical sections. The electrical consumption is 6 lacs units/month.
Fig 1.1 Layout of carriage workshop Matunga
The workshop carries out Periodical Overhaul (POH) and heavy corrosion repairs of
main line as well as EMU coaches. The target is to attend 269 coaches per month but actual
average attended is 243 coaches per month.
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Fig 1.2 Value Stream Mapping of workshop activities
Table 1.1 Symbols of value stream map
SR
No
CATEGORY
SYMBOL
SUB CATEGORY
1
DELAY 1
Unavailability of equipment
operator
2
DELAY 2
Unavailability of Tools, parts
and workspace
3
DELAY 3
Unavailability of appropriate
maintenance personnel
4
TIME LINE
NVA -Non value added time
VA -Value added time
If the non-value added time is reduced then the efficiency of the workshop will
increase and target can be accomplish on time. So railway will able to provide good service to
its passengers.
Overhead Cranes are used for moving the coach from one place to another in the
workshop. The disadvantages of overhead care are as follows.
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Disadvantages of Overhead Crane
Instability – Crane is unstable under unsecured load and if load capacity exceeded
from crane load carrying capacity
Communication - The point of operation is a distance from the crane operator or not
in full view of the operator
Training – Skilled and experienced crane operators only required
Maintenance or inspection – Daily proper inspection is needed and regular
maintenance is must
Major causes of accidents - Contact with power lines, Overturns, Falls, Mechanical
failures
Risk - Operators and persons at crane site are under risk
Cost – High installation and maintenance cost
Rope puller is the small machine used for short distance movement of the coaches in the
workshop.
Fig 1.3 Photo of Rope puller
Disadvantages of Rope puller
Small Capacity
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Used for short distance movement only
Uncontrolled motion
Difficulty in moving from one place to another
Noisy operation
Need of Modification
Fig 1.4 Cause Effect Diagram
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1.2 Aim and Objective of the Project
Aim
To Design the Hydraulic Rail Car Mover for better, efficient and safe work at
railway workshop
Objective
By utilizing leading edge technology to effectively provide rail car moving solution at
railway yard.
Using modern technology minimizing the potentials of risk and increasing the
efficiency of railway workshop.
To learn and practice new things.
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1.3 Report Layout
Chapter 2 includes literature review on hydraulics in general, rephasing hydraulic
system. The design and analysis process of hydraulic system and recent trends and computer
application in the field of hydraulics.
Chapter 3 provides the details of the operation of Hydraulic rail car mover and
Calculations of Hydraulic rail car mover force, speed, pressure and power pack, calculations
of the roller bearings. Also it includes the justification of assumptions.
Chapter 4 presents introduction to the pro engineer software and the model created
using pro engineer and details of hydraulic rail car mover cylinder parts.
Chapter 5 presents the introduction to the CAE software Patran and Nastran. And the
analysis of the axle dog arm using Patran and Nastran.
Chapter 6 draws general and specific conclusion from the research work documented
in this thesis.
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CHAPTER 2
LITERATURE REVIEW
2.1 Introduction to Hydraulics
The machines which are used to move the rail car in workshop are diesel engine,
overhead crane, Traverser, and rope puller. Even though these are not the most efficient or
productive methods, this equipment has been the traditional solution. The procedure also
requires using more than one person, regular maintenance, and is not as safe as more modern
methods.
Hydraulics was chosen for this application because it is the only form of power
transmission that can fit into the narrow confines of the application and still generate more
than 40 tons of thrust. Hydraulics totally dominated certain types of equipment in their
development.
Fig 2.1 Hydraulic power equipment trends
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Hydraulic systems are widely used in the industry. The system components like
pumps, valve, and cylinders are always became investigation topic in the history. Hydraulic
cylinders are one of the most common component of the hydraulic system used in many
engineering applications like; automatic manufacturing, heavy construction, control systems,
sensitive measurements and test systems. They are used in producing linear motion in
hydraulic systems and they convert hydraulic energy into mechanical energy.
2.2 Rephasing Cylinder System
Synchronized operation of two or more hydraulic cylinders can be attained by
plumbing volumetrically matched cylinders adjacent to each other where the displaced fluid
produces, equal, simultaneous, actuation of each cylinder in the system. As the volumes of
each cylinder cannot economically, be identically matched, a bypass port is provided that
upon full extension (or retraction) a metered amount of fluid bypasses the piston seal to the
next adjacent cylinder in the system. This indexes all cylinders of the system to the same
position, then upon retraction (extension) positive sealing is engaged and synchronized
operation continues.
Rephasing cylinders combine the functions of flow dividing/combining components
with that of actuators, saving space and weight. In addition, accuracy reportedly equals or
exceeds that of more-costly methods. Other advantages include lower parasitic power losses,
pressure intensification, and the ability to transfer power between actuators. The same
principle of Rephasing cylinder is used in Collinear Cylinder assembly. But instead of
external bypass tube inner pass tube through the piston is used to avoid external fluid lines.
The Collinear cylinders are used in indexer type rail car mover by Calbrandt Inc., Delano.
2.3 Recent Trends in hydraulics
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The technological trends are confirmation of the general consensus of industry. The goals
of fluid power which are successfully attainted to suit industrial trends are categorized as
Energy conservation
Leakage control
Fluid stability control
Proactive maintenance
Contamination control
Computer aided engineering
Microcomputer control
The maintenance strategies of hydraulic systems preventive maintenance and
predictive maintenance are well developed. New strategies such as proactive maintenance
techniques where the root causes of failure are continuously evaluated to provide an alert
before the system is damaged by some failure mode are being developed. It provides the basis
for self-compensation that is self-adjusting, self-lubricating, and self-limiting type of an
operation.
Contaminant monitoring is a large part of every maintenance. The techniques like
portable contaminant monitors which can do analysis and measurement of particulate
contamination have been brought out of clean room. The assessment of the degree of antiwear
protection provided by hydraulic fluid has made good progress in the last years. Through the
gamma rating for hydraulic fluids, it is now possible to not only select a fluid which will
adequately protect system components, but also ascertain the degradation of that fluid and pin
point fluid change periods.
The use of microcomputers for data acquisition has been overwhelming in most power
fluid laboratories. The major function of the microcomputer tends to be nothing but a monitor
for multiple sensors and data logger. The trend is in extending its use to do diagnosis and
troubleshooting which are parts of real time condition control.
2.4 Design and Analysis Process
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Fig 2.2 Hydraulic system design and analysis process
The generalized hydraulic Design and analysis process is illustrated in the above
figure. From the design goals, the design concept to be integrated into the hydraulic system
must be established and system schematic must be developed along with the operational
specifications for the system. Once these tasks are completed the component sizing and
selection process will enter. A hydraulic system is composed of interacting elements and
components. Therefore once the element component models are developed, the system model
becomes mathematical description of the way these elements and components interact.
Components model analysis is done using computer Software.
The actual performance characteristics are evaluated through laboratory and field tests
using the system prototype. Optimization is a function of process which is normally called as
cut and try.
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2.5 Computer Application in Hydraulics
In early days of computer modeling and simulation, the design engineer had not to
only be intimately familiar with fluid power components and systems, but he needed to be a
mathematical whiz and proficient computer programmer. But recent trend is to provide
designers with powerful PC based software to aid in their design mission. They only need to
know what software does and are not required to know how it does it.
Fig 2.3 Graph of modeling and simulation trends
Computational fluid dynamics, usually abbreviated as CFD, is a branch of fluid
mechanics that uses numerical methods and algorithms to solve and analyze problems that
involve fluid flows. Computers are used to perform the calculations required to simulate the
interaction of liquids with surfaces defined by boundary conditions. The commercial used
CFD solvers are Ansys fluent and CFX, CD-Adapco, Aerosoft Inc., etc.
ANSYS is engineering simulation software. Companies in a wide variety of industries
use ANSYS software. ANSYS offers a comprehensive range of engineering simulation
solution sets providing access to virtually any field of engineering simulation that a design
process requires. ANSYS ICEM CFD used as Pre/Post processor for solving fluid system. It
has tools for repair and to fix CAD complex geometries. It is first and foremost meshing tool,
significant mesh editing add power to meshing options. It is oriented towards experienced
users.
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A sophisticated Knowledge base Electronic Catalogue software which is available
allows the distributor to design a system, analyze the performance, select components,
provide circuit and element drawings, issue quotations etc. all on a PC.
The Tie rod collinear cylinders connected end to end are selected for hydraulic rail car
mover to cover the required long distance. A telescoping cylinder could have performed
functionally similar to the collinear cylinders. However, the multiple stages of motion and the
large piston area needed to generate the high thrust would have required a telescoping
cylinder too large to fit between the rails.
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CHAPTER 3
HYDRUALIC RAIL CAR MOVER:
DESIGN AND CALCULATIONS
3.1 Introduction
Hydraulic car mover can move 5 cars of 60 ton each at time at speed of 15 meter per
minute. The car mover provides higher productivity than overhead crane because only one
person can handle the system, the person controlling the movement right next to where the
work is being done, making it easy to position cars right where they need to be. The rail car
mover also requires less maintenance compared to using overhead cranes for positioning the
rail car.
An indexer type pushes the axle of a rail car using a single length assembly of
hydraulic cylinders mounted end-to-end and positioned parallel to the rail. The stroke raises
an axle dog from the floor to engage the axle of the rail car, and then the collinear cylinders
extend to move the car. The axle dog then drops back below floor level, and the cylinders
retract back to their home position.
Fig 3.1 Axle dog model
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3.2 Operation of the System
Hydraulic rail car mover consists of five cylinders mounted end-to-end in a collinear
arrangement. The first cylinder is stationary, from second cylinder, cylinders are mounted on
rollers and when its rod extends, it pushes on the cap end of the second cylinder. Likewise,
the rod of the second cylinder pushes on the cap end of the third cylinder, and so on. This
means that, theoretically, the rod end of the second cylinder moves at twice the relative
ground velocity as the first one. This is because the body of the second cylinder (which is
mounted on rollers, as are the third, fourth, and fifth cylinders) moves at the speed of the first
cylinder’s rod, and the rod of second cylinder extends at that same speed. Therefore, the rod
end of the fifth cylinder moves at five times the ground velocity as the first one.
In actuality, the stroke speed of any given cylinder varies. The piston acting against
the least resistance will move. However, the net result is uniform motion from the cylinders
sharing fluid routed in parallel.
Fig 3.2 Operational sequence schematic representation
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Fig 3.4 Schematic of Cylinder
When the control valve handle is moved toward the extend cylinder position,
hydraulic fluid under pressure is allowed to flow from the hydraulic pump to the piston side
of the cylinder 1. The check valve gets actuated at predefined pressure and part of the fluid
passes to the end cap of next cylinder through the inner tube. The extend fluid is restricted to
pass through outer pass tube using directional control check valve. While the oil under the
piston by the rod side of the cylinder 1 is allowed to flow from the cylinder and back to the
reservoir.
If the handle is pushed to the retract position, the pressurized oil is sent to the rod side
of the cylinder 1 from the hydraulic pump and the part of the fluid pass thorough the hole on
the piston rod to the end cap of next cylinder. Then at retract fluid pressure the check valve at
entry of the pass tube in each moving cylinder gets actuated and fluid the passed to the rod
side piston of the cylinders mounted on the rollers. Hence retracting all the cylinders and
pushing the oil on top of the cylinder 1 back to the reservoir.
3.3 Operation of Direction Control Check Valve
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Spring loaded direction control check valves are used to guide the fluid inside the
Hydraulic cylinder. The check valve senses the pressure and gets actuates and allows fluid to
pass in one direction only. The Schematic diagram of check valve is given below.
Fig 3.5 Check valve diagram
In Hydraulic rail car mover at two position direction control check valves are used.
One is inside piston inner tube entrance and another is at each pass tube entry. The valve
inside piston rod gets actuate at the pressure 2167.688kN/ m2
and allows fluid to pass in
forward direction. The valve at pass tube gets actuated at pressure 3545.91kN/m2
allows fluid
to pass in retraction motion.
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3.4 Calculations of Hydraulic Rail Car Mover
Cylinder bore diameter (D) = 165 mm = 0.165m
Length of cylinder (L) = 4400mm = 4.4m
Piston rod diameter (dpr) = 110mm = 0.11m
Piston inner tube diameter (d) = 50mm = 0.05m
Length of piston rod (l) = 4500mm = 4.5m
Pass tube diameter (dp) = 50mm = 0.05m
Length of pass tube (lp) = 4400mm = 4.5m
Axle dog cylinder bore diameter (da) = 30mm = 0.03m
Length of Axle dog cylinder (la) = 500mm = 0.5m
Cross section area of cylinder = π/4 * D2
= π/4 * 0.1652
= 0.02138 m2
Volume of one Cylinder = area * length
= 0.02138 * 4.4
= 0.09407 m3
-------- A
Volume of Piston inner tube = π/4 * d2
* l
= π/4 * 0.052 * 4.5
= 0.008639 m3 -------- B
Volume of Pass tube = π/4 * dp2
* lp
= π/4 * 0.052* 4.5
= 0.008639 m3 -------- C
Volume of axle dog cylinder = π/4 * 0.032 * 0.5
= 0.000353 m3
-------- D
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Total Volume = A * 5+ B * 5 + C * 4 + D * 2
= 0.5488 m3
Total volume in liters = 548.8 lit
Time required = 3 min
Flow rate = 4.5733 * 10-3
m3/sec
Pump required capacity = 182.93 lit/min
= 72.43 gallons/min
Weight of rail car = 60 ton
Number of rail car = 5
Total weight of rail car = 300 ton
Total distance to be covered = 22 m
Acceleration = 0.122 m/s2
Assume motion is pure rolling motion and 15% extra load for design.
Force required to move the rail car = mass * acceleration
= (300 * 103 + 0.15 * 300 * 10
3)* 0.122
= 42090 N
Pressure required = Force/ Area
= 42090/0.01187
= 3545.91 KN/m2
Pressure head = pressure/ density of water* 9.81
= (3545.91*103)/ (1000*9.81)
= 361.45m
Selecting SAE 30 oil, density of oil is 830 kg/m3
Assume overall efficiency (η) = 82%
Power required = (ρoil * g * H * Q)/ (1000 * η)
= (830*9.81*361.45*4.5733*10-3
)/ (1000*0.82)
= 16.41kw
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Select 18kw motor and 75gpm pump
75gpm = 0.004731m3/ sec
Maximum operating pressure of pump = (P*1000* η)/ (ρoil *g* Q)
= (18*1000*0.82)/ (830*9.81*0.004731)
= 383.16m of water
= 3758.78kN/m2
Pushing area = cross section area of cylinder – area of piston inner tube
= 0.02138 – 0.001963
= 0.019417m2
Pressure required in extension= (42090/0.019417)
= 2167.688kN/ m2
Max Force in extension = Pushing area * operating pressure
= 0.019417 * 3758.78
= 72984.23N > 42090N
= Hence OK
Pulling area = cross section area of cylinder – area of piston rod
= 0.02138 – 0.009503
= 0.01187m2
Pressure required in retraction= (42090/0.01187)
= 3545.91kN/m2
Max force in retraction = Pulling area * operating pressure
= 0.01187 * 3758.78
= 44616.7N > 42090N
Hence Design is ok.
Weight of an axle dog = 100 kg
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Cross section area of dog cylinder = π/4 * da2
= π/4 * 0.03
2
= 7.068 * 10-4
m2
Pressure required to operate axle dog = (100 * 9.81)/ (7.068 * 10-4
)
= 1387.94kN/m2
Velocity in forward direction = flow rate/ pushing area
= 0.004731/ 0.019417
= 0.2436 m/sec
Speed of rail car in forward direction = Velocity in forward direction * 4
= 0.974 m/sec
Theoretical time required to move the coach in forward direction is 21.44 sec
Velocity in retraction = flow rate/ pulling area
= 0.004731/ 0.01187
= 0.3985 m/sec
Speed of rail car in reverse direction = Velocity in retraction * 4
= 1.594 m/sec
Theoretical time required to move the coach in reverse direction is 35.06 sec
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3.5 Design of Roller Bearing
Number of bearing = 24
Total load carried = 42000 N
Radial Load on each bearing (Fr) = (42000/24)
=1750 N
Axial load on each bearing (Fa) = 500 N
Speed (N) = 200 RPM
Life required (Lh) = 16000 hrs.
Probability of survival = 93%
Life in million revolutions for 93% Probability of survival
Lmr = (Lh*60*N)/ 106
= 192 mr
Life in million revolutions for 93% Probability of survival
L07/L10 = (ln(1/P07)/ ln(1/P10))1/b
Where,
b = constant for ball bearing = 1.34 from PSG data book
P07 = 0.93
P10 = 0.90
L10 = 253.59 mr
Calculation of approximate equivalent load
Using excess radial load factor
Peq = (V*X* Fr *S*Kt)* Kr
Where,
V = 1 for outer race bearing
X = 1 radial load factor
S = 1.1 service factor
Kr = 1.3 excess radial load factor
Kt = 1.06 temperature factor for operating temp 130 degree
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Peq = (1*1*1.1*1.3*1.06*1750)
= 2652.65 N
Calculation of Dynamic capacity
Using load life relationship
C = (L10)1/k
* Peq
Where,
K = 3, constant ref PSG data book
C = (253.59)1/3
* 2652.65
= 16788.93 N
= 1711.41 kgf
Ref PSG design data book
Select SKF 6011 deep groove ball bearing with dynamic capacity 2200 kgf.
Page 34
3.6 Justification of assumptions
Alloy Steel is used as cylinder material because of its high strength and corrosion
resistance properties. Ease of Manufacturing is also criteria for selection of material.
The system is design to fit under rail car within available space. The length of the system in
home position is 27m and fully extended position length is 50m. There are no external fluid
lines in the system except main line from source to the first fixed cylinder.
Operability of the system is very easy. It does not require any special training for
using the machine. It requires only one person and the person operating the rail car mover can
take safe position and monitor the operation. As compare to overhead crane where controls
are at a height, operator have to climb to platform to operate the crane hydraulic rail car
mover controls are simple.
The use of PLC circuits permits remote control operation. Operator can keep eye on
operating pressure indicated on pressure dial. The initial cost of the hydraulic rail car mover is
Table 3.1 Cost of Hydraulic Rail Car Mover
Hydraulic rail car mover Part Cost of the part (INR)
17kw motor 50000
75gpm pump 150000
5 cylinders 300000
Other cost 400000
Total approximate value 900000
The initial cost of hydraulic rail car mover is less than initial cost of overhead crane it
costs almost 25-30 lacs per unit. The power requires for hydraulic rail car mover is 18kw but
power consumption of the overhead crane is 25kw. Hence the operating cost of hydraulic rail
car mover is less than overhead crane for same number of working hours. The numbers of
parts which require maintenance are less hence the maintenance cost is also less than the
overhead cranes.
Page 35
CHAPTER 4
MODELLING USING PRO ENGINEER
4.1 Introduction to Pro/E
Pro/ENGINEER is a feature based, parametric solid modeling program. As such, its
use is significantly different from conventional drafting programs. In conventional drafting
(either manual or computer assisted), various views of a part are created in an attempt to
describe the geometry. Each view incorporates aspects of various features (surfaces, cuts,
radii, holes, protrusions) but the features are not individually defined. In feature based
modeling, each feature is individually described then integrated into the part. The other
significant aspect of conventional drafting is that the part geometry is defined by the drawing.
If it is desired to change the size, shape, or location of a feature, the physical lines on
the drawing must be changed (in each affected view) then associated dimensions are updated.
When using parametric modeling, the features are driven by the dimensions (parameters). To
modify the diameter of a hole, the hole diameter parameter value is changed. This
automatically modifies the feature wherever it occurs - drawing views, assemblies, etc.
Another unique attribute of Pro/ENGINEER is that it is a solid modeling program. The design
procedure is to create a model, view it, assemble parts as required, then generate any drawings
which are required.
The assembly model of Hydraulic Cylinder is created in ProE by using different parts
of cylinder created in ProE. These ProE models can be used for doing analysis using Ansys
software with ICEM CFD solver. The analysis will give the pressure in the cylinders, speed of
the system, operating temperature, and cylinder can be tested for buckling etc.
4.2 Hydraulic Cylinder Model
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Fig 4.1 Hydraulic cylinder Assembly model
4.3 Models of Parts of Hydraulic Cylinder
Fig 4.2 Model of Front end and Back end
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Fig 4.3 Model of Piston and piston rod
Fig 4.4 Model of Piston rod end
4.4 Cross sections of Hydraulic Cylinder model
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Fig 4.5 Cross section of Front part of cylinder
Fig 4.6 Cross section of Rear part of cylinder
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CHAPTER 5
ANALYSIS OF ARM USING PATRAN/NASTRAN
5.1 Introduction
Patran is the world's most widely used pre/post-processing software for Finite Element
Analysis (FEA), providing solid modeling meshing facility which facilitates the placement
of loads and restraints, analysis setup and post-processing for multiple solvers including
MSC Nastran, Marc, Abaqus, LS-DYNA, ANSYS, and Pam-Crash.
Fig 5.1 Steps in analysis
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MSC Nastran is the world's most widely used Finite Element Analysis (FEA) solver.
When it comes to solving for stress/strain behavior, dynamic and vibration response and
thermal gradients in real-world systems, MSC Nastran is recognized as the most trusted
multidiscipline solver in the world.
The model of the axle dog arm is created using the ProE software. Then it is imported
to the Patran for finite element analysis where it is meshed using meshing tools. The load and
constraints are applied. Later processing is done using Nastran solver. The results of Nastran
are access in Patran.
5.2 Design of Axle Dog Arm
The Axle length of the rail car is 1524mm. The straight arm was enough to push the
rail car but there is difficulty in operation of the arm because of the brake linkages restricting
the motion of the arm. So the arm is design in U shape. And the other end of the arm is hinged
to the platform so it can rotate about the pin.
There are two arm positioned opposite to each other in the system. These arms hold
the axle shafts of trolley. While one arm is pushing the rail car the other arm is used for
controlling the motion of the rail car. They are operated by different hydraulic cylinders. The
pressure required to operate the hydraulic arm is 1387.94kN/m2.
The maximum stress in the
arm is 1.42 * 103 N/mm
2 calculated using Nastran.
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Fig 5.2 Model of axle dog
Fig 5.3 Meshing and load applied using Patran
5.3 Results of Nastran
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Fig 5.4 Result constraint forces
Fig 5.5 Result Stress and Displacement
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CHAPTER 6
CONCLUSION AND FUTURE SCOPE
Indian railway workshop is most busy place for 365 days and still workload is
increasing continuously. The demand for frequent and faster railway service is increasing.
Therefore there is need for modern better, safe techniques to replace conventional methods
which are also creating more pollution.
The Hydraulic rail car mover is better option to use for movement of the rail cars
under workshop. Hydraulic rail car mover will save the time required in workshop by
eliminating interference of shunting department in the movement of the rail car. It doesn’t
require skill person to operate the machine. And the cost of installation and maintenance is
also less compared to overhead carne.
It is more safe and convenient for the peoples working in workshop than threat of
overhanging load. Hence Hydraulic rail car mover system is better.
Further this systems performance can be analyze using computer engineering Software
like Ansys ICEM CFD. Check the reliability of the Hydraulic rail car mover using the
computer testing Software. By changing the parameters like pressure, power, dimensions
systems performance can be optimize. And by making prototype of the system more
performance parameters could be understand.
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CHAPTER 7
REFERENCES
JOURNAL
Dr E. C. Fitch, Dr Richard K. Tessmann, Dr Ing T. Hong (1999), “Fluid Power Goals
and Trends”, FES Technology publication
Paul Johnson (2011), “Aggressive hydraulic machinery”, Magazine Hydraulics and
Pneumatics July 2011, page no. 26-30
BOOK
R. S. Khurmi , “Fluid Mechanics and Hydraulic Machines”, S Chand publications
V. B. Bhandari , “Design of Machine Elements”, Fourth edition, McGraw Hill
publications
R. S. Khurmi, J. K. Gupta, “ Machine Design”, S Chand publications
“Design Data Book of Engineers”, PSG college of Technology
WEB
http://www.aggressivehydraulics.com/products/cylinder-component-parts/
http://www.calbrandt.com/products/axle-type-railcar-mover#1
http://www.ehow.com/about_5403188_parts-hydraulic-cylinder.html
http://en.wikipedia.org/wiki/patran_nastran
http://www.bardyne.com/Publications/Literature.htm#11