Yadbir Singh

SuYa3r

B  

S

Axle 

ubmitted by  adbir Singh    rd year studenhabha Institu

SUM

Box Cyl

                                              nt of Mechanute of Techno

MMERE

lindrical

       (14 JU

                                              ical Engineerlogy Kanpur D

ER TEPOl Roller Bogie

UNE 2010 t 

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TRAORTBearinges) to 12 JULY 

ININT g for Loc

2010 ) 

                     S                                      Vehi   RDSO Mana

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comotiv

Submitted to S.k Sachanicle, Motive Pak Nagar,Luck

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Power know 

Page 2 of 50 

Page 3 of 50  

ACKNOWLEDGEMENT

I would like to extend my heartfelt thanks and deep sense of gratitude to all those who helped me to writing this Report. First, I would like to express my sincere thanks to my sir Mr. S.K Sachan of RDSO, Manak Nagar, Lucknow. I would also like to express my thanks to Er. Bhupendra Singh, NTPC Singarulii, special thanks to Surjeet Kumar in RDSO. Motive Power.

This most sincere and important acknowledgement and gratitude is due to my parents, who have given their moral boosting support and encouragements at some stage of this endeavor.

Yadbir Singh Students of Mechanical Engineering

Bhabha Institute of Technology, Kanpur, India.

Email Id. [email protected] [email protected]

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INDEX Sr.No Contains Page NO. 1. Introductions about RDSO 5 2. Quality objectives for the

year 2008- 09 6-7.

3. Infrastructure and RDSO Lab.

7-11

4. Nomenclature adopted by the Indian railways for the locomotives operating on the Indian railways.

11-15

5. Bearings (General Description) 

16-20

6. Terminology for servicing tools 20-21. 7. Disassembly of roller

bearing axle boxes 21-22

8. Cleaning of bearings, axle boxes and components

23-24

9. Checking of axle journals, axle boxes, roller bearings and components

25-26

10. Assembly 26-29 11. Lubrication 29-31 12. Periodic attention and

service inspections 31-37

13. Running instructions and inspection of bearings of locos involved in fire, floods and accidents

38-39

14. General instructions regarding cleanliness, storage and handling of bearing

39-40

15. Replacement of bearings parts and interchangeability of axle boxes

40-41

16. Terminology of bearing defects

42-45

17. Bearing used in Indian railways

46-48

18. Bearing life Calculation 48-49.

1Rdsestsyw(CspdtophacnCcoro

CRn(RThbyEh

1 INTR

Railways weevelopment everal comptandardizatioystems, the

was set up inCSO) in 19pecificationsesigns and mo foreign cohenomenal ctivity, whicew organiz

Centre (RTRConducting aolling stock,

Central StandResearch Cen

amed ReseRDSO) in 1

The status oeaded by a Dy Additiona

Executive Dias various d

RODUCTIO

ere introducprogressed

pany managon and co-oIndian Railw

n 1903, follo930, for pres. Howevermanufacture onsultants. Wincrease in

ch increased zation calledC) was setupapplied resepermanent w

dards Office ntre (RTRCearch Desi1957, under f RDSO ha

Director Genal Director Girectors, heairectorates fo

ON

ced in Indiathrough to

ged systemsordination away Conferewed by the

eparation of r, till indepof railway e

With Indepencountry’s ithe demand

d Railway p in 1952 at earch for dway etc.

(CSO) and C) were integ

gns and Ministry of

as been channeral The DiGeneral, Sr. ading differ

for smooth fu

a in 1853 o the twents grew up. amongst varence AssociaCentral Stan

f designs, stpendence, mequipments wndence and industrial an

d of rail tranTesting an

Lucknow fodevelopment

the Railwaygrated into Standards f Railways nged from rector GenerExecutive D

rent directorunctioning.

and as theiieth century

To enforcrious railwaation (IRCAndards Offictandards anmost of thwas entrustethe resultan

nd economisportation -nd Researcor testing ant of railwa

y Testing ana single uniOrganizatioat Lucknowan RDSO iral is assisteDirectors anrates. RDSO

ir y, ce ay A) ce nd he d

nt ic a h

nd ay

nd it n

w. is d

nd O

Page 5 of 50 

Page 6 of 50  

2.QUALITY ASSURANCE Hitherto, the quality assurance function in respect of

vendor approval and purchase inspection of these items including publication of vendor directories was being looked after by individual technical directorates of RDSO along with their normal functions of research, development and standardization. To impart greater thrust to quality assurance, Railway Board has approved the creation of a separate Quality Assurance Organization at RDSO in Sept.2002 for Technical disciplines i.e. Mechanical Engineering. Including M&C, Civil Engineering. S&T & Electrical Engineering. Each headed by Executive Director under the overall charge of an HAG officer. With the creation of this Quality Assurance Organization, focused attention and close monitoring of vendor approval and purchase inspection activities.

FUNCTIONS

RDSO is the sole R&D organization of Indian Railways and functions as the technical advisor to Railway Board Zonal Railways and Production Units and performs the following important functions :

Development of new and improved designs.

Development, adoption, absorption of new technology for use on Indian Railways.

Development of standards for materials and products specially needed by Indian Railways.

Technical investigation, statutory clearances, testing and providing consultancy services.

Inspection of critical and safety items of rolling stock, locomotives, signaling & telecommunication equipment and track components.

GOVERNING COUNCIL Governing Council comprises of Chairman, Railway Board as Chairman; and Financial Commissioner, Member Engineering, Member Mechanical, Member Staff, Member Electrical, Member Traffic, Addl. Member (Plg)/ Railway Board and Director General, RDSO as its members. The functions of Governing Council are:

To identify and approve the R&D projects for technology development on Indian Railways.

To review the progress of projects.

Page 7 of 50  

To determine the quantum of direct investment in technology development within the overall allocation of funds under the plan head 'Railway Research'.

To give direction for improving the working of RDSO.

CENTRAL BOARD OF RAILWAY RESEARCH Central Board of Railway Research (CBRR) consist of DG/RDSO as Chairman, Addl. Member (Civil Engineering.), Addl. Member (Mechanical Engineering), Addl. Member (Elect.), Addl. Member (Sig), Addl. Member (traffic), Advisor (Finance), Executive Director (E&R), Executive Director (Plg.)/Railway Board as members and Addl. Director General/RDSO as member secretary. Non- Railways members of CBRR consist of eminent scientists, technologists, engineers and senior executives of other research organisations, academic institutions and industrial units related to railway technology and materials. Functions of CBRR are:

To consider and recommend the programmers of research on Indian Railways.

To review the research programmers from time to time.

To ensure coordination and assistance from other research laboratories.

To review the ongoing projects from the technical angle.

3 INFRASTRUCTURE

RDSO has a number of laboratories which are well equipped with research and testing facilities for development, testing and design evaluation of various railway related equipments and materials. Some of these are:

1) Air Brake Laboratory is equipped with facilities for simulating operation of air brakes on freight trains up to 192 wagons and 3 locomotives as also for simulation of passenger trains up to 30 coaches. Brake Dynamometer Laboratory has facilities to develop and test brake friction materials for locomotives, coaches and wagons. A unique facility in India, this laboratory has also been used by R&D organizations of Ministry of Defense like DMRL, DRDL and HAL for indigenization of brake pads for defense aircraft.

Page 8 of 50  

B&S Laboratory has a 6mx14m heavy/testing floor on which full scale models of beam (spans up to 10 m, slabs, columns, towers, shells and other components made of concrete, steel, brick etc can be tested under static, dynamic or pulsating loads. A high frequency ranging 250-700 cycles/min pulsate for the application of a pulsating loads varying from 2 to 20 tones and a maximum static load of 40 tonnnes on heavy duty testing floor. The Laboratory is equipped with analogue strain indicator, multi channel dynamic strain recording system, switching & balancing units, acoustic emission equipment, data acquisition system etc. for recording various parameters. Diesel Engine Development Laboratory has four test beds capable of testing diesel engines from 100 to 6000 HP with fully computerized systems for recording of over 128 test parameters at a time. This facility has already enabled RDSO to develop technologies for improving fuel efficiency, reliability and availability of diesel engines as well as to extract higher output from existing diesel engines. Fatigue Testing Laboratory for testing prototype locomotive and rolling stock bogies, springs and other railway equipments subjected to stress and fatigue so as to ascertain their expected life in service. Geo-technical Engineering Laboratory is equipped with facilities for determining strength parameters of soil in lab and field condition. The State-of-art Sub-surface Interface Radar (SIR) system, Laser based soil particle analyzer, and computerized consolidation test apparatus have been installed in the lab. The lab also has computerized Static Triaxial Shear apparatus for determining the strength of soil as well as the design of embankment. Metallurgical & Chemical Laboratory is capable of destructive and non-destructive testing of metals, polymers, composites, petroleum products and paints for providing information to be used in design and also for monitoring performance of materials in service. The M&C laboratory include Scanning Electron Microscope, Direct reading spectrometer, Ultrasonic Flaw Detector and other non destructive examination equipment, polymer and composite evaluation facilities, thermal analyser, corrosion engineering evaluation facilities including weather meter, static 760 hour AR test rig for grease testing. V2F dynamic test rig for grease testing, lube oil filter evaluation rig Cetane rating machine & 50t machine for rubber deflection characteristics. Psycho-Technical

2) Laboratory for assessment of critical psycho-physical attributes of operational staff such as drivers, switchmen and station masters for efficient operation. The ergonomic laboratory of psycho-technical Dte is also equipped with bio-feedback

Page 9 of 50  

system for assessment of EMG, GSR (Galvanic Skin Resistance) temperature, pulse and respiration rate & is used for stress management exercises. Signal Testing Laboratory for testing of all types of signaling equipments such as safety signaling relays, block instruments, power supply equipments, point machines, signaling cables, electro-mechanical signaling equipments/ components etc. There is an exclusive environmental testing section equipped with environmental testing facilities as per ISO 9000. These is including, programmable heat, humidity & cold chambers, mould growth, dust, rain chambers. Signaling Equipment Development Centre has been set up in the Signaling Lab. In this Centre, working signaling equipment & systems have been set up. The working systems include SSI, universal axle counter, VLSI axle counter, AFTCs, block instruments etc. In addition, equipment developed by RDSO, such as signaling relays, poly-carbonate lenses, LED signal lamps, triple pole double filament lamps, power supply equipment etc., have also been displayed. This centre will be used for testing minor improvements in designs of SSI, axle counters etc., as well as for imparting training to newly inducted Inspectors.

3) Track Laboratory for testing full scale track panel under dynamic load patterns similar to those encountered in service. Stresses at the various locations of track components under simulated load conditions are measured and recorded for analysis. This has helped in rationalising and optimising design of track structures for Indian conditions. The facility of fatigue testing of welded rail joints is also available. n connection with joint research project of UIC on rail defect management, RDSO has been entrusted with lab testing of rail samples from various world railways under simulated loading conditions.Special rail tensioning system for application of longitudinal forces on rail samples to simulate the thermal forces of the field has indigenously been developed, installed and commissioned in track lab. This system, with capacity of up to 150 tonne in static condition, is being used to conduct testing of different rail samples. Mobile Test Facilities

4) for recording of track parameters, locomotive power and conducting oscillograph trials for evaluating vehicle-track interaction as also for monitoring track conditions. For condition monitoring of OHE under live line and to facilitate directed maintenance of electrification, a Network of testing and recording apparatus (NETRA) car, first of its kind, developed by RDSO is actively in service for scanning OHE in Railway. Vehicle Characterization Laboratory for conducting

Page 10 of 50  

vehicle characterisation tests on railway vehicles to study the behaviour of suspension systems and to determine natural frequencies

5) Centre for Advanced Maintenance Technology at Gwalior for upgrading maintenance technologies, and methodologies. Also to achieve improvements in productivity and performance of all railway assets and manpower. This covers reliability, availability, utilization and efficiency.

6) LIBRARY Considerable efforts and resources were devoted on the development of an outstanding Library collection to meet the expanding needs of Research and Development. The Library has more than 1.70 lakhs volumes which includes books, reports, specifications, and translations on Science, Engineering, Technology, Management and Railways. About 100 technical journals and magazines both Indian and foreign origin are received in the Library regularly.

Page 11 of 50  

4 Nomenclature adopted by the Indian railways for the locomotives

operating on the Indian railways.

The numbering system of locomotives comprises two parts. First, the code prefix such as 'WDM-2' or 'WAM-4' which denotes the type/class of the loco; and second, a serial number such as '17604'. Each letter in the code-prefix has a specific significance, and the understanding of this would help us in the overall understanding of the nomenclature adopted on IR, as well as the varied types of locomotives running on the IR.

The first (left-most) letter denotes the gauge. Thus, 'W' stands for Broad Gauge, 'Y' is Metre Gauge and 'Z' is Narrow Gauge. We will normally see one of these letters as the first letter in the number of the loco.

The Steam Saga

In the bygone era, life was simple, because there was only one category of loco, based on the fuel is used. Those were days of the elegant, huffing and puffing steam locos, also colloquially called 'coal engines'. In those days, on the broad gauge, we had:

'WP' class locos, with a hemispherical front, which gave the loco a very majestic and powerful look.

'WG' class locos, which had a flat front.

The letters 'P' and 'G' indicated Passenger service and Goods service, respectively. Its means that 'WP' was a broad gauge passenger service loco, while 'WG' was a broad gauge goods service locomotive. Due to the shift to diesel and electric traction, both these types of locos are no longer in service on IR, and can be seen only in museums.

On the meter gauge, we had the omnipresent 'YP' class locos, which, unlike their broad-gauge counterparts (WP), had a flat front. The goods trains on the meter gauge were pulled by 'YG' class locos, which had a look similar to the 'YP' locos.

Thus, in the days of steam traction, the second letter indicated the 'service class' of the loco, and mainly the 'WP'. 'WG', 'YP' & 'YG' class of steam locos dominated the IR scene.

The Change from Solid to Liquid Fuel

Then, in the sixties, came diesel traction, and life became a little more difficult. Most of the diesel locos operating on broad gauge are 'WDM-2' series, where 'W' is Broad Gauge, 'D' is Diesel, and 'M' is 'Mixed' (service). These versatile locos, made in India at DLW,

Page 12 of 50  

Varanasi under license from ALCO, USA, have put in an exceedingly meritorious and long service in hauling passenger as well as goods trains, both singly and in pairs.

The number '2' indicates that it is a second generation loco, from design technology point of view. Its predecessor 'WDM-1' was used in much smaller numbers and were last seen on the Durg-Nagpur section of South Eastern Railway, hauling goods trains. The peculiarity of the WDM-1 was that it had the driver's cab only on one end, while the other end was flat -- like the ends of passenger coaches. So, while it appeared flush with the load behind it, the WDM- 1 had to be reversed for the journey in the opposite direction. On the other hand, 'WDM-2', though unsymmetrical, can be used in any direction without the need of reversing, thanks to the design of its driver's cab.

WDM-2's cousin on the meter gauge is an equally versatile 'YDM-4', while that on the narrow gauge is ZDM-1. You will also find 'WDS-4' bringing passenger trains into platform at the starting stations. ('S' indicates 'shunting class'). There are other variants such as 'WDP-1' ('P' for 'passenger service', and higher-powered (3100hp), 'WDP-2' and 'WDG-2' locos for passenger and goods service respectively.

While 'WDM-2' and its related variants are based on ALCO designs, IR has recently gone in for a new technology, powerful (4000hp) locos based on the designs of General Motors, USA. These locos are christened 'WDG-4' ('G' for Goods), and these are manufactured at DLW. These locos can be seen operating on the Hubli Division of the South Central Railway, hauling goods trains carrying bulk ore.

On the narrow gauge, locos such as 'ZDM' operate on Kangra Valley Railway and Kalka-Shimla Railway, while other narrow gauge variants pull tourist trains on the Neral-Matheran Railway near Mumbai.

The Electric Locomotives

The advent and the progress of Electric Traction has further complicated the numbering system. From a simple 'WP' or 'WG', we now move on to more complex nomenclatures such as 'WCAM-3', an addition of as many as 3 characters. But this addition is not without adequate meaning, as we will realise after the following discussion.

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while all othere fed by AC25,000V AC

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Page 13

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Page 14

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Page 15 of 50  

another technology transfer agreement (with General Motors, USA). This 4000hp, 160km/h loco will be found in increasing numbers as the production gradually increases.

While on one side this technology transfer was under progress, IR, through Chittaranjan Locomotive Works and RDSO, have in parallell developed an indigenous, powerful 5000hp loco for freight traffic, called the 'WAG-7'. This loco is already under manufacture at CLW, and can operate at speeds upto 100km/h.

A Technological Challenge for the Railway Engineer

Since Mumbai Division is the only division on IR to have DC overhead supply, there is a need to change from DC to AC (or vice-versa) for trains going out of (or coming into) Mumbai. This changeover takes place at three locations. On the Central Railway route towards north and east, this change takes place at Igatpuri -- on the platform -- in the form of change of the locomotive. On the south-bound route, the changeover is to a diesel loco, at Pune station. But the most interesting is the changeover on the Western Railway route, towards Vadodara/Delhi. This change happens while the train is in full motion -- without any stopping or jerks whatsoever. To achieve this, the trains on Mumbai Central - Vadodara / Ahmadabad route are operated by 'dual-traction' locos of WCAM series. (BG, DC and AC traction, Mixed service). The changeover takes place just north of Virar, over a neutral section, while the passengers inside the train normally remain oblivious of such a major (technical) happening!

The Numerals

After having discussed and understood the alphabetic nomenclature prevalent in naming the locos operating on IR, let us take a brief look at the numerals too. Today, most locos have a 5-digit number after the type-code. The first two digits (from left) also signify the type of the loco, and the remaining three digits denote the serial number in that category. Thus WAP-4 class locos always have numbers beginning 22, while WCG class locos start with 20. The new generation WAP-5 and WAG-9 locos have numbers in the 30 and 31 series.

Page 16 of 50  

Axle Box Cylindrical Roller Bearing for Locomotive Bogies) 

5 BEARINGS

(GENERAL DESCRIPTION)

The cross-sections of cylindrical axle roller bearings with the location of all the

parts of the assembly on the journal.

The assemblies are a combination of two separate bearings capable of taking radial as well as axial thrust loads.

The roller bearing is composed of a cylindrical inner and an outer race/ring along with rollers and cages. The cages while carrying no load keep the rolling elements axially apart and also prevent the later from falling out while handling. The outer ring is a slide fit on the axle box housing while the inner ring is an interference fit on the axle journal forming part of the axle when in place. The rollers have a special cylindrical profile, which enables uniform and effective load distribution.

The bearing parts are made of nickel-chromium / carbon chromium alloy steels except cage, which is of solid brass / brass riveted.

The full analysis of heavily loaded plain bearings is extremely complex. For so called ‘lightly-loaded bearings’ the calculation of power loss is simple for both journal and thrust bearings. Important factors are, load capacity, length ton diameter ratio, and allowable pressure on bearing material. Information is also given on rolling bearings. The terms rolling-contact bearing, antifriction bearing, and rolling bearing are all used to describe that class of bearing in which the main load is transferred through features in rolling contact rather than in sliding contact. In a rolling bearing the starting friction is nearly twice the running friction, but still it is negligible in comparison with the starting friction of a sleeve bearing. Load, speed, and the operating viscosity of the lubricant do affect the frictional characteristics of a rolling bearing. It is probably a mistake to describe a rolling bearing as “antifriction,” but the term is used generally throughout the industry, the study of antifriction bearings differs in several respects when compared with the study of other topics because the bearings they specify have already been designed. The specialist in antifriction-bearing design is confronted with the problem of designing a group of features that compose a rolling bearing: these features must be designed to fit into a space whose dimensions are specified; they must be designed to receive a load having certain characteristics; and finally, these features must be designed to have a satisfactory life when operated under the specified conditions. Bearing specialists must therefore consider such matters as fatigue loading, friction, heat, corrosion resistance, kinematic problems, material properties, lubrication, machining tolerances, assembly,

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Page 17

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g, and rings . The st the

n one ection sides. ugh a on is shaft used.

Page 18 of 50  

Double-row bearings are made in a variety of types and sizes to carry heavier radial and thrust loads. Sometimes two single-row bearings are used together for the same reason, although a double-row bearing will generally require fewer parts and occupy less space. The one way ball thrust bearings are made in many types and sizes. Some of the large variety of standard roller bearings is available, straight roller bearings carry a greater radial load than ball bearings of the same size because of the greater contact area. However, they have the disadvantage of requiring almost perfect geometry of the raceways and rollers. A slight misalignment will cause the rollers to skew and get out of line. For this reason, the retainer must be heavy. Straight roller bearings will not, of course, take thrust loads. Helical rollers are made by winding rectangular material into rollers, after which they are hardened and ground. Because of the inherent flexibility, they will take considerable misalignment. If necessary, the shaft and housing can be used for raceways instead of separate inner and outer races. This is especially important if radial space is limited. Bearing Life When the ball or roller of rolling-contact bearings rolls, contact stresses occur on the inner ring, the rolling element, and on the outer ring. Because the curvature of the contacting features in the axial direction is different from that in the radial direction, the equations for these stresses are more involved than in the Hertz equations presented in If a bearing is clean and properly lubricated, is mounted and sealed against the entrance of dust and dirt, is maintained in this condition, and is operated at reasonable temperatures, then metal fatigue will be the only cause of failure. Inasmuch as metal fatigue implies many millions of stress applications successfully endured, we need a quantitative life measure. Common life measures are • Number of revolutions of the inner ring (outer ring stationary) until the first tangible evidence of fatigue

Page 19 of 50  

Bearing Load Life at Rated Reliability When nominally identical groups are tested to the life-failure criterion at different loads, To establish a single point, load F1 and the rating life of group one (L10)1 are the coordinates that are logarithmically transformed. The reliability associated with this point, and all other points, is 0.90. Thus we gain a glimpse of the load-life function at 0.90 reliability. Using a regression equation of the form FL1/a = constant the result of many tests for various kinds of bearings result in • a = 3 for ball bearings • a = 10/3 for roller bearings (cylindrical and tapered roller) A bearing manufacturer may choose a rated cycle value of 106 revolutions (or in the case of the Timken Company, 90(106) revolutions) or otherwise, as declared in the manufacturer’s catalog to correspond to a basic load rating in the catalog for each bearing manufactured, as their rating life. We shall call this the catalog load rating and display it algebraically as C10, to denote it as the 10th percentile rating life for a particular bearing in the catalog. Selection of Tapered Roller Bearings Tapered roller bearings have a number of features that make them complicated. As we Address the differences between tapered roller and ball and cylindrical roller bearings, Note that the underlying fundamentals are the same, but that there are differences in detail. Moreover, bearing and cup combinations are not necessarily priced in proportion to capacity. Any catalog displays a mix of high-production, low-production, and successful special-order designs. Bearing suppliers have computer programs that will take your problem descriptions, give intermediate design assessment information, and list a number of satisfactory cup-and-cone combinations in order of decreasing cost. Company sales offices provide access to comprehensive engineering services to help designers select and apply their bearings . Form The four components of a tapered roller bearing assembly are the • Cone (inner ring) • Cup (outer ring) • Tapered rollers • Cage (spacer-retainer) The assembled bearing consists of two separable parts: (1) the cone assembly: the cone, the rollers, and the cage; and (2) the cup. Bearings can be made as single-row, two-row, four-row, and thrust-bearing assemblies. Additionally, auxiliary components such as spacers and closures can be used. A tapered roller bearing can carry both radial and thrust (axial) loads, or any combination of the two. However, even when an external thrust load is not present, the radial load will induce a thrust reaction within the bearing because of the taper. To avoid the separation of the races and the rollers, this thrust must be resisted by an equal and opposite force.

Page 20 of 50  

One way of generating this force is to always use at least two tapered roller bearings on a shaft. Two bearings can be mounted with the cone backs facing each other, in a configuration called direct mounting, or with the cone fronts facing each other, in what is called indirect mounting. shows the nomenclature of a tapered roller bearing, and the point G through which radial and axial components of load act.

6 TERMINOLOGY FOR SERVICING TOOLS.

The following is the terminology of the commonly used tools for servicing

and maintenance of axle roller bearings: -

TOOLS USES

a) Lead or copper hammer (sledge) For tapping races/rings etc. while assembling and disassembling

b) Micrometer (inside and out side) For measuring axle box bore and journal diameter etc.

c) Feeler gauge For measuring diametrical and axial clearances of the bearings, etc.

d) L – Gauge (as shown in fig-6) For measuring the respective distance of inner races/rings and thrower/labyrinth ring from journal end.

e) Induction heater or oil bath heater with tank, scissor- tongs, asbestos hand gloves, stirrer, thermometer etc.

For mounting inner races/rings on axle journals.

f) Puller tool or induction heater. For extracting inner races/rings from axle journals.

g) General fitter tools like spanners, pliers etc.

--------

h) Torque wrenches of different capacity (from 5.0 to 100.0 Mkg.)

For tightening bolts and nuts.

i) Scrappers For general cleaning

j) Dial-indicators To check deflection on axle etc.

k) Magnifying glasses To examine spalls, etc. on races/rings.

Page 21 of 50  

l) Deep and shallow washing trays For washing bearing parts etc.

m) Thin hard wooden scoop For removing old grease from bearings and housings.

n) Wooden blocks For positioning under the housing lug liner to prevent the bearing housing from turning while disassembling etc.

o) Brushes (stiff and bristle type) For cleaning purpose, etc.

p) Lint-free towels To wipe bearing and components, etc.

q) Wire mesh basket For placing the bearing components, etc.

r) Ultrasonic machine To check the internal cracks on the axle journal

s) Metal top table For placing the axle box housing during assembly.

General Instructions & Precautions

Work only with clean tools. 

Proper tools should be used for different operations. 

Avoid damage, injury or distortion to any part of the bearing while 

working with tools. 

Do not use any kind of mallet. 

Do not use gas torch to heat inner races and thrower / labyrinth ring. 

7 DISASSEMBLY OF ROLLER BEARING AXLE BOXES

For disassembly of axle box bearings after service for inspection, repair and re-lubrication, the following procedure is recommended:-

Clean thoroughly axle box cover and outside portions of axle boxes with wire brush before attempting any work on bearing to prevent ingress of dirt into the bearing.

Take off the front covers after removing the bolts / nuts.

Unfold the locking plate and take off the end clamping screws.

Remove end clamping plate.

Remove loose lip from the journal end.

Page 22 of 50  

Withdraw the axle box assembly from the axle journal leaving the inner races/rings, inner distance piece/journal distance ring and thrower/labyrinth ring in position on the axle journals. Use extractor/hand-sling, if necessary.

Place the axle box assembly in a horizontal position on a suitable table.

Remove thrower end cover/labyrinth cover in case of separate, thrower end cover / labyrinth cover axle box.

Push out the outer races/rings with bearing assembly and distance pieces/rings from the axle box housing without applying direct force on the bearings or cages.

General instructions and precautions: Ensure that the bearing with its other components, are not damaged during

disassembly.

Keep some quantity of used grease in a dry container for subsequent investigation, if necessary.

Before disassembling the outer races/rings, divide the full circle of the outer races into four parts of 90º each and number 1, 2, 3 and 4 consecutively; mark the date when any load bearing part is brought into service, with an electric etching pencil. The load bearing zone should be changed to improve the fatigue life of outer race whenever the bearing is disassembled.

Do not interchange bearing parts. Keep them as matched sets and exercise care to see that the complete roller bearing set is returned to the outer race/ring from which it was removed.

Disassembly of inner races/rings, thrower/labyrinth ring etc. from journal :

If it becomes necessary to remove inner races/rings and thrower/labyrinth ring from the axle journal, the following shall be the procedure: -

Apply the extractor tool for removal of inner races/rings, inner distance piece/journal distance ring and thrower/labyrinth ring.

Use three-jaw or two-jaw puller (whichever is required) positioning behind the removable part, in the manner as shown in fig. 4.

Apply pressure to the end of the axle by rotating the long bolt.

o Precaution: Do not apply puller tool bolt directly to the lathe centre tapped holes of the axle end.

Follow instructions furnished with the heater.

Heat the inner races/rings and thrower/labyrinth ring by induction heater to a temperature not exceeding 1200C (250ºF) and not longer than the period specified in the operating instructions of induction heater.

Page 23 of 50  

Then use the puller indicated above.

o Precautions:

Do not use oxy-acetylene torch for the removal of races/rings and thrower/labyrinth ring.

Use asbestos gloves while handling hot components.

Ensure that the journal does not get any heat.

8 CLEANING OF BEARINGS, AXLE BOXES AND COMPONENTS

Bearing and components cleaning:

Whenever bearings are removed from bogie for overhauls, inspection, repairs and replacement or re-lubrication, the following shall be the cleaning procedure if manual cleaning is done. :-

Remove the bulk of grease with a thick hard wood scoop from all bearing parts.

Place roller bearing parts such as bearing assemblies, distance pieces/rings, loose lip etc. except axle box and it accessories in a wire mesh basket.

Suspend the basket suitably in a container of pure, clean oil, preferably kerosene or MTO.

Allow bearing and bearing parts to soak, preferably, overnight or until the grease has been sufficiently softened.

Agitate the basket slowly through the oil from time to time to remove as much as possible of dirt, grease, etc.

Lift the basket and drain the oil. If for any reason, it is necessary to ascertain the nature of foreign matter removed, strain the oil through a filter paper and collect the residue.

Transfer all parts to a second container of clean oil.

Clean each part individually with a brush, partially submerging in oil.

Do repeated soaking and cleaning if necessary until all traces of grit is removed.

Sponge out all parts with a non-fluffy rag or with a wiping towel for inspections.

Clean finally in petrol or white spirit before re-assembly.

Page 24 of 50  

General instruction and precautions :

Do not use any alkaline degreasing agents. Water based cleaning methods may lead to corrosion of the bearings.

Take care that hairs from brush do not stick in cage pockets. etc.

After final cleaning, the re-assembly should be done as early as possible, to avoid any possibility of corrosion, etc.

If bearing units are not to be re-assembled immediately, shake off the liquid, dry and provide a protective coating of antirust compound, and wrap the parts in a water proof paper or polythene sheet and store in a dry room.

Use only clean and dry compressed air, if desired, for drying bearing parts.

Do not spin uncleaned bearings.

Do not use same container for initial cleaning and final rinsing of bearings.

Cleaning Mediums: Use only water-free cleaning medium, the following are some of the cleaning mediums generally used :-

Petrol 

White spirit (low Flash point) 

Kerosene 

MTO (Mineral Turpentine Oil)  

Axle-box and accessories cleaning :

Scrap accumulation of dirt off outside of the box.

Wash axle box, covers, screws, nuts, spring washers, etc. after extracting bearings in a boiling soda solution.

Rinse thoroughly in clean, hot water.

Wash inside and outside of box, cover etc. with clean kerosene.

Ensure that the threaded holes on the box are clean.

Blow out with compressed air and after drying, coat with light machine oil or with the same grease as used for lubrication on the housing bore, and all machined or ground surfaces, after proper inspection and final repair.

Protect the box and its accessories from dirt and dust until re-assembly.

Precaution: Sand-blast cleaning of roller bearing equipped axle assemblies is prohibited.

Page 25 of 50  

9 CHECKING OF AXLE JOURNALS, AXLE BOXES, ROLLER

BEARINGS AND COMPONENTS

Checking of Axle journal :

After thorough cleaning, check axle journal for any bending by measuring it with the help of dial gauge at four places 90º apart. Bent axle may cause premature bearing failure.

Ensure that the axle journal diameter is within the permissible limits, laid down in relevant drawing.

Taper and opacity of axle journal should be within permissible limit.

Axle journal should be examined for internal or superficial cracks by ultrasonic testing machine.

Checking of Axle box housing:

After thorough cleaning, check the damage, score mark and cracks on axle box body and covers for their soundness of material.

Examine traces of corrosion, if any, on working surfaces of the axle box body, remove it with fine emery paper.

Ensure that all the dimensions of the axle box housing and covers are within the permissible limits, laid down in relevant drawings.

Check particularly the bore dia., depth, ovality and taper of the bore and other internal dimensions of axle box housing. If they are not within the limits as prescribed in relevant drawing, the housing should be set aside for rectification / rejections.

Inspect axle box lugs, liners, etc.

Checking of roller bearings:

a) Any damage to the rollers and raceway should be brought to notice of the concerned section engineer.

b) In case, rotation is not free, this may be due to some dirt inside. The bearing may be washed with white spirit or petrol and re-dipped in rust preventive oil.

c) Dimensional details are shown in manufacturer's drawings and may be checked for better fitment.

d) Check and ensure radial internal clearances of the bearings to the value specified in the table below:

For NEI bearing For FAG bearing

Page 26 of 50  

Radial clearance

(Under free condition)

0.100 to 0.165 mm. 0.165 to 0.215 mm.

Checking of components:

Thrower/labyrinth ring: If the thrower/labyrinth ring is found damaged or dismounted for any reason, the same should not be reused.

Felt/Sealing ring: The felt rings should be changed compulsorily during the overhauling of the axle box. Felt/Sealing ring must never be reused.

Clamping plate and Distance pieces/rings: These components should be examined for dimensional correctness, flatness and cracks before they are used.

Locking bolts/studs and nuts: If the nuts and bolts/studs do not fit properly to each other, they must be replaced.

Locking plates: The locking plates should be changed compulsorily when the axle box is dismantled.

6 ASSEMBLY

Outer race/ring assemblies in housing

Thoroughly clean the inside surface of “axle box housing” and “thrower end cover/labyrinth cover” with kerosene oil and subsequently, after drying, with petrol.

Apply a thin coating of light machine oil or grease over the cleaned dry housing bore.

Place the axle box housing over a clean metal.

Take out the outer race/ring assemblies from their original wrappings and place squarely. Place one of the outer races (with its stamped face facing outwards) into the housing and slide it until it buts squarely against the housing mating surface

Next slide the outer distance piece/housing distance ring, keeping one of the grease hole of the outer distance piece/housing distance ring (if greasing is done through the axle box crown) concentric with the housing crown grease nipple hole.

Page 27 of 50  

Slide the second outer race/ring assembly in the same manner as previous one.

For separate thrower end / labyrinth cover:-

I. Fix the studs for separate thrower end cover/labyrinth cover on the box rear end.

II. Place thrower end cover/labyrinth cover with rubber sealing ring in position. Ensure its proper bedding against the outer race/ring. Contact area should not be less than 60-70 % of total surface. Use feeler gauge for this purpose.

III. Place the tab-washer in position and tighten the four nuts evenly and lock them.

1) Follow on with the sliding of the end distance piece/ring

i) j) Keep the axle box in a dry and clean place, after fixing a card-board on the box openings for protection from dirt and moisture, until it is required for remounting.

k) Remove card-board just before the mounting on the axle journal.

l) Apply lithium base grease of recommended brand into the axle box fitted with outer races/rings before mounting.

m) Smear well the annular grooves on the thrower/labyrinth ring end of the box with specified grease to form an effective grease seal.

To mount thrower/labyrinth ring, inner races/rings and inner distance piece/journal distance ring on the axle journal, the following shall be the procedure

a) Inspect the axle journal for its correct size, surface finish, permissible taper and ovality, as per the relevant drawing.

b) Clean thoroughly the axle journals and holes at the axle ends.

c) Check for any bulging of the axle ends, which may occur at the time of wheel pressing.

d) Clean thoroughly the thrower/labyrinth ring, inner races/rings, and inner distance piece/journal distance ring with kerosene oil and subsequently with petrol when dried up.

e) There are two methods for heating thrower/ labyrinth ring and inner races/rings to shrink fit on axle journal as given bellow:

1. By oil bath heater:

1.1 Immerse inner races/rings and thrower/labyrinth ring in oil bath heater tank. These should not come in contact with hot plates.

1.2 Heat the inner races/rings and thrower/labyrinth ring to a temperature not exceeding 120ºC and not longer than 30 minutes. Ensure strict temperature control so that oil bath temperature does not exceed the above temperature.

2. By induction heater:

Page 28 of 50  

2.1 Put the thrower/labyrinth ring and inner races/rings on the induction heater. Follow instructions furnished with the heater.

2.2 Heat the inner races/rings and thrower/labyrinth ring by induction heater to a temperature not exceeding 120ºC (250F) and not longer than the period specified in the operating instructions of induction heater.

2.3 Demagnetise the inner races/rings and thrower/labyrinth ring.

f) Shrink thrower/labyrinth ring on the axle and ensure its positive abutment with axle shoulder. Check up its correct fitment in relation to the axle ends by means of suitable ‘L’ gauge.

g) Shrink the lip type inner races/rings, inner distance piece/journal distance ring and plain inner race/ring one after another on the axle journal

General instructions and precautions:

a) Use only clean light transformer oil as heating medium.

b) Prevent bearing parts making contact with the bottom of the tank by providing wire-netting tray.

c) Stir the oil during heating.

d) Remove excess oil from bore of the inner races/rings and thrower/labyrinth ring with clean lint-free cloth before mounting.

e) Do not heat inner distance piece/journal distance ring.

f) Hold firmly all the components (thrower/labyrinth ring, inner races/rings, etc.) against their relevant abutment surfaces on the axle journal until cooled down for gripping. For this purpose use of pusher tool as shown in Fig. 6.4 is recommended.

g) Use asbestos gloves while handling hot component.

h) Ensure that 60-70% of abutting surfaces remain in contact with each other. Use of feeler gauge is recommended for this purpose.

Mounting the axle box assembly :

To mount the axle box assembly, the following procedure is recommended:-

a) Pack axle box assembly with specified grease Smear grease between the interstices of the cage and rolling elements by hand, rotating the bearing to assist penetration.

b) To increase the efficiency of seal, fill the concentric grooves in the shoulder of the box with grease.

c) Lift the box assembly in an upright position in level with the axle journal to bring bearing box horizontal axis in alignment with journal axis.

Page 29 of 50  

d) Keep box end in relations to axle

:Sl. No.

Screws Torque Values (in Mkg.)

1. M10 5.00

2. M16 22.00

3. M20 42.50

4. M 22 58.00

5. M26 98.00

6. 1 1/8" 7UNC 96.00

7. 7/8" BSW 53.25

8. 3/4" 10UNC 32.50

General Instruction and Precaution :

a) Smear the threads of bolts, screws, etc. with oil.

b) Do not resort to hammering action on axle box assembly while sliding the axle box assembly on axle journal.

c) Check for indications of slipping or rotations of thrower/labyrinth ring and inner races/rings before mounting the axle box.

11 LUBRICATION

Whenever lubricated surfaces slide together at low sliding speeds or with a high appliednormal load, the lubricant may not separate the two solid surfaces completely. However, the lubricant can still signiÞcantly reduce the friction coefÞcient by reducing the shear strength of adhesive junctions between the two surfaces. In this so-called boundary lubrication regime, the effectiveness of the lubricant can be improved if the lubricant molecules adhere well to the solid surfaces. This is best accomplished by introducing a lubricant or additive that forms a surface Þlm through adsorption, chemisorption, or chemical reaction with the surface. The ensuing reduced shear strength of the surface Þlm can lower the friction coefÞcient by as much as an order of magnitude from the dry friction value. When a good supply of a viscous lubricant is available, the separation between the surfaces will increase as the sliding speed increases or the normal load decreases. As the separation increases, the amount of solid/solid contact between the surfaces will decrease, as will the friction coefÞcient and wear rate. In this Òmixed frictionÓ regime, friction is determined by the amount of plowing deformation on

the softer surface by the harder surface asperities and by adhesion within the solid/solid contacts. When the surfaces become completely separated by a self-acting or externally pressurized lubricant Þlm, the lubricating regime is hydrodynamic, wear is reduced to

Page 30 of 50  

nearly zero, and friction reaches a low value governed by viscous shear of the lubricant. Friction coefÞcients in such cases can be 0.001 or lower, depending on the surface velocities and the lubricant viscosity. This is the case for most journal or thrust

bearings (see subsection on ßuid Þlm bearings). Bearings for Friction Reduction Most mechanical systems contain moving components, such as shafts, which must be supported and held in position by stationary members. This is best done by appropriate design or selection of bearings to be used wherever the moving member is to be supported. Most bearings may be classiÞed as either bearings, dry or semilubricated bearings, or rolling element bearings. Fluid Þlm bearings (see subsection below) have a conformal geometry, with a thin Þlm of ßuid separating the two surfaces. The ßuid lubricant could be a liquid, such as oil, or a gas, such as air. Fluid Þlm bearings are commonly used to support rotating cylindrical shafts, and the load on such a bearing could be either radial, in which case the bearing is called a journal bearing, or axial, for a thrust bearing.

In most cases the ßuid Þlm is generated by the motion within the bearing itself, so the bearing is called self-acting or hydrodynamic. Whether or not a self-acting bearing can develop a ßuid Þlm sufÞcient to separate and support the two surfaces is determined by magnitude of the quantity mU/W, where m is the (absolute) ßuid viscosity, U is the relative sliding velocity, and W is the normal load. If that quantity is too small, the ßuid Þlm will be too thin and high friction will occur. This can be a problem during startup of equipment when sliding velocities are low. That problem can be overcome by pressurizing the ßuid Þlm from an external pressure source to create a hydrostatic bearing. Whether the ßuid Þlm is externally pressurized (hydrostatic) or self-acting (hydrodynamic), separation of the solid surfaces allows wear to be essentially eliminated and friction to be very low, even when very large loads are carried by the pressurized lubricant. Dry and semilubricated bearings (see subsection below) have conformal surfaces which are in direct contact with each other. This category includes bearings which run dry (without liquid lubrication) or those which have been impregnated with a lubricant. Dry bearings are made of a material such as a polymer or carbon-graphite which has a low friction coefÞcient, and they are generally used in low-load and low-speed applications. Semilubricated bearings are made of a porous material, usually metal, and are impregnated with a lubricant which resides within the pores. The lubricant, which could be oil or grease, cannot provide a complete ßuid Þlm, but usually acts as a boundary lubricant. Semilubricated bearings can carry greater loads at greater speeds than dry bearings, but not as high as either ßuid Þlm or rolling element bearings. The failure mechanism for both dry and semilubricated bearings is wear.

General instructions and precautions : Use only the approved and recommended lithium base greases listed under.

Use calibrated pressure grease gun.

Avoid excess lubrication. Excess lubrication will invariably result in increased running temperatures, reducing the effectiveness of the lubricants.

Page 31 of 50  

Do not heat the grease to facilitate application. Heating separates the oil from the soap in the grease and grease loses the desirable properties.

Keep lubricants in clean and covered container free from dirt and water.

Used lubricant should never be re-used even though it may appear to be in good condition.

Approved and recommended lubricants : Servogem RR3 of Indian Oil Corporation

Multi-grease LL3 of Balmer Lawrie

Note: Grease Servogem RR3 of Indian Oil Corporation and Multi-grease LL3 of Balmer Lawrie are compatible to each other.

o Quantity of lubricants recommended per axle box:

For topping up: About 0.027 to 0.045 kg. of specified grease is recommended for topping up after 6 months interval or covering 80,000 kms., whichever is earlier.

For re- /initial lubrication :

About 2.71. kg. of specified grease is recommended for axle box to NEI drg. no. 92-4271C and X-115 applicable for WDM2, WDS5, WDS6, WDS8, WCG2, WAG5A, WAM4, WAM4A, WAM4B and WCAM1 locos.

About 2.3. kg. of specified grease is recommended for axle box to M/s FAG drg. no. 901-02-101 applicable for WDM2, WDS5, WDS6, WCG2, WAG5A, WAM4, WAM4A and WCAM1 locos.

About 1.75 kg. of specified grease is recommended for axle box to NEI drg. no. 92-4253 applicable for YDM4 and YDM4A locos. .

12 PERIODIC ATTENTION AND SERVICE INSPECTIONS

Trip inspection  

  Recommendations   Remarks 

a)  Visually examine the axle box for any damages from any striking objects or for any unusual condition.

                       ‐‐‐‐‐‐‐ 

b)  Check  for  missing  or  proper 

locking of  cover  studs/bolts  and 

other parts. 

                      ‐‐‐‐‐‐‐ 

c)  Investigate lubrication leakage at    Correct immediately even a slight leakage of grease observed at the

Page 32 of 50  

housing joints, etc. front end of the box. However, a slight leakage of lubricant, if noticed at the rear end, it should be considered as normal.

d)  Observe for any signs of over‐

heating on the outside portions of 

the box.  

  Do not allow running temperature more than 25º C (77º F) above ambient.

e)  Look for loose, cracked or missing 

axle‐box and pedestal liner. 

  Repair or replace missing liners.

f)  Attend booked repairs, if any.    --------

Half - yearly inspection (M-12) (12 months in case of electric locomotives to coincide with AOH Schedule):

a) Repeat items of trip inspection. --------

b) For checking of longitudinal and lateral clearances wear limits of axle box and pedestal liners, see bogie maintenance manual no. MP.MI. – 71/78 (latest revision)

Record figures in respective schedule forms.

c)  Remove  end  cover  of  the  axle 

boxes  and  examine  visually  the 

condition  of  the  grease  and 

locking arrangement of bearings. 

  If  grease  is  found 

discolored/disintegrated,  then 

disassemble  the  axle  box  and 

clean  the  bearing  thoroughly 

according  to  instructions  laid 

down  in  previous  chapter. 

Examine  the  bearings with  their 

elements minutely. Re‐assembly, 

checking,  re‐lubrication  should 

be  done  according  to  the 

instructions  laid  down  in  this 

manual. 

d)  Top  up  as  required  with 

specified grease to each axle box 

with  pressure  gun,  if  the 

condition  of  grease  and  bearing 

parts are satisfactory. 

  Use the same grease used  in the 

box. Inject 27 to 45 grams. (30 to 

50  cc)  of  recommended  grease 

into  the  box  through  grease 

nipple  without  disturbing  the 

bearing assembly. 

Page 33 of 50  

e)  Ultrasonic examination may be coincided with axle box greasing in M‐12 

schedule  for  convenience  of  the  shed.  The  mandatory  periodicity 

however remains 12 months only. 

Yearly inspection (M-24) (24 months in case of electric locomotives to coincide with second AOH Schedule):

Where axle boxes are removed for wheel turnings or wheel changes, they have to be invariably overhauled.

The overhaul of axle-boxes can be done at the time of bogie/traction motor overhaul etc. Normally overhaul of axle boxes is not required earlier than three years. But at this stage it is recommended to overhaul the axle boxes every yearly schedule (24 months).

a) Remove the axle box assembly from the bogie.

b) Dismantle axle box assembly as indicated in chapter-3.

c) Examine grease. If found discoloured, blackened or rust coloured, it may be taken as evidence of wear or pitting rust. In such a case, the bearing should be examined carefully. If it does not show any discolouration, then clean thoroughly all bearing parts and axle box (complete) as indicated in chapter 4.

d) Look for evidence of possible defects or other imperfections, which might make the bearing unsafe for service. Examine all bearing parts for any of the following defects and scrap if such defects are discovered (use magnifying glasses where necessary).

i) Severe smearing caused by abuse, etc.

ii) Corrosive pitting caused by moisture or other corrosive agents.

iii) Brinelling caused by vibrations, which result in depression or grooves.

i) Breaks or cracks.

ii) Check for any indication of slipping or rotation of thrower/labyrinth ring.

iii) Pitting caused by electric currents.

e) Examine outer-races/rings as follows:-

  Inspections Remarks

i)  Look for evidence of rotation in the housing bore on the outer surfaces of the ring.

Remove the cause. It may be either due to excessive interference of the inner race/ring over the journal or defective bearing. Replace the bearing if rotation is severe.

ii)  Examine roller paths (as far  This will minimise the danger of 

Page 34 of 50  

possible) carefully for any 

surface spalling or cracks or any 

other irregularities which will 

warrant removal from service. 

premature fatigue and / or 

spalling of the race load zone. 

iii)  Rotate the outer race/ring a 

quarter turn to bring into 

operation un‐used part, mark 

the part quadrant number, date 

on which the said quadrant is 

brought into service by electric 

etching pencil on the side 

surface of the outer race/ring. 

This will minimise the danger of 

premature fatigue and / or 

spalling of the race load zone. 

f)  Examine inner races/rings as follows: 

i)  Look for evidence of rubbing or 

turning on the journal. 

The cause may be inadequate 

interference. If suspected, 

replace the bearing with under 

size bore bearing. 

ii)  Inspect roller path (load zone 

track) for spalling or any other 

defects. 

There may be inadequate 

diametrical clearance. If 

suspected, replace the bearing 

iii)  Look for the surface 

imperfection. 

In case of any doubt, inner 

race/ring may be subjected to 

dye‐penetration test. If found 

faulty, replace it. 

g) Axle-box inspection and repairs :

Remove excessively worn out manganese steel liners or which have cracked and replace them with new liners as outlined below :-

i) Grind free at least two sides of the old liner welds, make free with a steel chisel remaining welds.

ii) Grind off remaining weld deposits, if any.

iii) Apply new liners, make sure they fit flat.

iv) Hold liners tight against box with clamps.

v) Keep the box submerged in water except the area where welds are to be done.

vi) Do all welding in down-hand position.

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vii) Use approved low-Hydrogen welding electrode.

viii) Follow the procedure for welding of manganese steel liners as laid down in RDSO MP.MI.NO. 97/81.

ix) No welding of liners should be done with bearing in position.

x) Check the bore of the axle box housing and ensure that it is within the permissible limits. If not, reject the axle box.

h) Manganese steel liners:

For method of repair and precaution regarding Manganese steel liners, see RDSO MP.MI.-97/81.

For re-assembly of axle box for further service, follow procedure indicated in Chapter 6.

i) Precautions:

i) Use of oxy-acetylene torch for removal of old liner plates from axle box is not recommended to avoid possibility of distortion.

ii) In the welding of manganese steel liners care must be taken in order to prevent cracking, that is obtained from unfavorable weld metal dilution as well as heat build up.

iii) Factors within the control of the welder to reduce base metal heat build up are holding a short arc, short welding periods, lowest possible current and the use of the smallest diameter electrode consistent with the thickness of the section to be welded.

iv) The best ductility is retained in welding of the material (manganese), by keeping the work as cool as possible.

v) Where there are number of boxes to be welded on, these shall be arranged in a row so that the same location can be welded on each box progressively. Then return to the first box and repeat in a different location on each box. In this way the boxes get maximum cooling time between welds.

vi) At no time shall the arc to be struck on the face of manganese liners. Arc-strikes on liners are potential crack starters and are known to cause base metal failure when highly stressed.

vii) No welding shall be done on liners to box until the preceding weld area is cooled to the touch of the hand.

viii) All welds shall be visually inspected.

Six-yearly inspection or POH :

(a) Repeat items of yearly inspection.

(b) Remove inner races/rings and thrower/labyrinth ring, (as per instructions given in this manual) for visual inspection of their inner surfaces and for inspection of the axle journal surface, only if any cause for suspicion as to the proper fitment or functioning of the parts or defect is noticed. Proper fitment may be ascertained by individual’s experience on hearing the

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metallic sound of the mating surfaces between inner races/rings, thrower/labyrinth ring and axle journal.

It may be added that unnecessary withdrawal of bearing elements from their seatings causes deterioration of fitting surfaces and may damage the bearing races/rings too. Special care must be taken to ensure that the bearings and its components i.e. cage, rollers and races/rings are not damaged during dismantling operation.

(c) If inner races/rings and thrower/labyrinth ring are withdrawn from the journal, inspect them for fretting corrosion between inner race/ring and axle journal. Fretting reduces the solid contact between the inner race/ring and journal, causing the race/ring to loosen.

(d) Clean and examine the bearing seating on the axle, paying special attention to the shoulder for the thrower/labyrinth ring on the axle and all fillets. Ensure these dimensions are within the limits laid down. Scrap axles with any defect indications on the journal or journal fillets.

(e) Renew all sealing rings.

(f) Check the rollers for any fretting or corrosion by rotating each roller.

(g) Re-assemble axle box for further service if everything is in good condition, as indicated in Chapter-6.

(h) Mount only inner and outer races/rings with roller assemblies and insert feeler gauge between the rolling elements and inner race/ring while lifting the outer race/ring to take its weight off the feeler gauge and see that the diametrical clearance between roller and races/rings(in free state) within the limits given in clause 5.3.d of chapter 5.

General instructions and precautions:

a) Keep a complete inspection record at the shed at all times using journal box and axle serial number and box location on locos, as reference.

b) While replacing new bearing or any new bearing parts from the original packing, do not clean. Clean only when original packing are damaged or have become dirty.

c) Also do not remove any bearing parts from original packing until immediately before mounting.

d) When applying a used inner race/ring on a used axle journal, prefer to use an inner race/ring with little or no signs of fretting.

e) If journal is found under size, use under size bore inner race/ring.

f) If races/rings are not immediately applied on journals that have passed inspection, protect at all times against possible damage from water, dirt or other substances. This is applicable in the case of journal also.

g) If wheel and axle assemblies are not immediately applied to bogie, turn each axle box a few time every few days to prevent the parts from remaining in the same position for any appreciable length of time to

Page 37 of 50  

prevent corrosion on contacting surfaces due to galvanic action and condensation due to atmospheric temperature changes.

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13 RUNNING INSTRUCTIONS AND INSPECTION OF

BEARINGS OF LOCOS INVOLVED IN FIRE, FLOODS AND ACCIDENTS

Running instructions:

When cleaning locomotives with the aid of steam, care should be taken to avoid spraying the axle boxes, which should be protected with covers of canvas or similar material.

In the event of any trouble developing in the axle box roller bearing when in service, in between terminals as indicated by noise, excessive heat at box or any abnormal condition, follow the procedure indicated bellow:

a) Stop the loco, examine the axle box carefully.

b) Move the loco, slowly under close observation to the next stopping, or to the point where the loco can be conveniently set off for attentions, if the examination does not disclose any condition which makes it unsafe to run.

c) Stop the loco and intimate authorities concerned, if during this movement, excessive noise is present indicating any possible broken parts in the bearing or the wheels begin to slide, or the box does not cool down.

d) Consider as abnormal any running temperature 25ºC (77ºF) above ambient for operation.

e) Book any repairs or any abnormal condition observed in the run in the "Drivers booked repair card" giving the following particulars to receive closer attention at the next inspection points:

i) Date of failure.

ii) Details of operating sections, kilometerage where bearing has failed or was found defective.

iii) Train number and loco number.

iv) Capacity and type of service.

v) Loaded or empty.

vi) Location of defective bearing on the loco.

vii) Whether journal was hot.

viii) Axle box serial number, if available.

ix) Description of defects.

Locos involved in an accident:

When locos with axle roller bearings are involved in a derailment or suspected or damaged from any such causes, the following procedure is recommended:

a) Dis-assemble and inspect the bearings for any damages or other defects before putting the loco back in to service.

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b) Check axle for bending by measuring inside distance on wheel flanges at four places 90º apart. A bent axle may cause premature bearing failure due to oscillation movement and uneven load distribution in the bearing, scrap all bend axles.

c) Inspect side frames also to see that they are not bent or distorted. Side frames, which are also bent or distorted, will cause undesirable loads on the bearing assembly, which can cause premature bearing failures.

d) Check spring sets for any evidence of cracks or breakage. If any crack/breakage found, replace the seat. Do not repair by welding or by any other method.

e) If it is found necessary to do electric welding any where on locos with axle roller bearings, the grounding cable must be clamped to near the part being welded to prevent any return current passing through the bearings.

Locos operating in floods:

Do not operate locos equipped with axle roller bearings through water except in emergency, when properly authorised to do. However, inspect for any accumulations of water in the journal, if suspected, mark the axle box for repacking of grease.

Locos involved in fire - hazards:

a) Do not operate locos, which have been in fire. The heat might have possibly done some injury to the bearing.

b) Disassemble, clean, inspect and re-lubricate the bearings. Fire shows appreciate discoloration of the surface of the parts, which would help to judge the suitability of the bearing for further service.

14 GENERAL INSTRUCTIONS REGARDING

CLEANLINESS, STORAGE AND HANDLING OF BEARING Cleanliness:

a) In all roller bearing work, the first and primary consideration is cleanliness. Therefore, the instructions listed here under should always be scrupulously observed.

b) Set apart a clean and dry area inside the shop for all roller bearing work. Protect the area by partition from wind blow, dirt, grit and moisture from adjacent areas, and allowing at the same time ample light at the workshop.

c) Work only with clean tools.

d) Use clean wiping towels. Do not use waste or rags which will adhere to the metal surfaces.

e) Keep your hands clean while handling bearings.

f) Work on clean benches covered with clean papers.

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g) Avoid contact of cleaning solvents, grease etc. with the skin as far as possible, as a possible precaution against skin trouble, such as dermatitis.

Storage and Handling:

Extreme care must be exercised when storing and handling bearings and spare parts. The following is a list of suggestion, in general, which could be followed:

a) Store all bearings or bearing spares in dry and sheltered places. Dampness may ruin them in a short time.

b) Bearing should not preferably be stored in assembled condition.

c) Except bronze cage, all bearing parts and all machined surfaces of axle box and its parts should be kept greased to prevent rusting while in storage.

d) Do not remove bearing parts from original packing until immediately before assembly.

e) Inspect occasionally parts in storage.

f) Exercise care to prevent "finger-rust", on finished surfaces of bearings and parts, while handling, due to moisture on the fingers.

g) Do not allow bearings to lie around uncovered on bare floors where there are accumulations of water, dust or dirt.

h) Storage tracks for wheel mounted with roller bearing must be so arranged that the wheel flanges of one pair of wheels can not strike the adjacent roller bearing box to avoid any damage.

15 REPLACEMENT OF BEARINGS PARTS AND

INTERCHANGEABILITY OF AXLE BOXES Replacement of bearing parts (individually) :

a) The inner races/rings, outer race/ring assemblies (with cages and roller),thrower/labyrinth ring and distance pieces etc. are inter-changeable within the same make.

b) If the journal is found under size, use the step size inner races/rings as shown in manufacturer’s drawing.

Interchangeability of axle boxes:

Regarding interchangeability of NEI Roller bearing axle box to drg. no. 92-4271C with FAG roller bearing axle box to drg. no. 901-02-101, following guide-line should be followed:-

a) FAG and NEI axle box assemblies are interchangeable in totality, not in component level.

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b) No attempt should be made by the railways to intermix the components of one make with the others, as these components are not mutually interchangeable.

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16 TERMINOLOGY OF BEARING DEFECTS 

Following is the list of bearing damages or defects and corrective actions:‐ 

Sl. 

No. 

Defect and condition Causes Corrective action

1.  Rust  and  corrosion:

Surface  becomes 

partially  or  fully 

rusted.  Sometimes 

rusted  at  spacing 

equal  to  distances 

between           rolling 

elements. 

Improper storage 

Improper packaging 

Insufficient rust preventative  Invasion of moisture, acid etc. 

Handling with bare hands  Bearing  is  stationary  for  long 

period 

Take measures  to  prevent rusting while  in  storage  to eliminate the causes. 

2.  Fretting:  Fretting 

surfaces  wear 

producing  red 

coloured  particles 

that form hollows 

Insufficient interference  Insufficient lubrication  Fluctuating load  Vibration  during  transport  or 

when not operating conditions 

Improve fit 

Check surface roughness of journal and housing 

Check  consistency  of grease 

Do  not  use  worn  out  or damaged housings 

3.  Flaking:  Flakes  form 

on  the  surfaces  of 

the  raceway  and 

roller  elements. 

When  the  flakes  fall 

off,  the  surface 

becomes  rough  and 

uneven. 

Excessive  loads,  fatigue  life, improper handling 

Improper mounting 

Insufficient precision of journal and housing 

Insufficient clearance  Contamination 

Rusting  Passing  of  electric  current through bearing 

Softening  due  to  abnormal temperature rise 

Find  the  cause  of  heavy load 

Check  internal  clearance regularly 

Improve  precision  of journal and housing 

Improve  operating conditions 

Improve  method  of assembly and handling 

Check  grease  and  greasing method 

4.  Seizure:  Bearing 

heats  up,  becomes 

discolored  and 

Insufficient clearance  Insufficient grease  Bad quality of grease  Excessive load  Rollers skewing 

Check  grease  type  and quantity 

Check  internal  clearance regularly 

Improve  method  of 

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eventually seizes up.  Softening  due  to  abnormal temperature rise 

assembly and handling 

5.  Cracking:  splits  and 

cracks  in  bearing 

rings and rollers. 

Rapid heating during mounting

Excessive shock load  Improper handling, use of steel hammer  and  impact  of  large foreign particles 

Surface  deformation  due  to improper lubrication 

Excessive interference  Large flaking  Overheating by creeping 

Avoid  rapid  heating  of bearing during mounting 

Reconsider  operating condition  

Improve  method  of assembly and handling 

Prevention of creep  Do  not  use  excessively worn‐out  or  deformed housing 

6.  Rolling  path 

skewing:  Roller 

contact  path  in 

raceway  surface 

strays of skews. 

Deformation  or  tilt  of  bearing due to  insufficient precision of journal or housing 

Improper mounting 

Insufficient  rigidity  of  journal and housing 

Re‐check  internal clearance 

Re‐check  precision  of journal and housing 

Investigate  rigidity  of system 

7.  Smearing  and 

scuffing:  Surface 

becomes  rough  with 

small deposits. 

Improper lubrication 

Invasion of foreign matter 

Roller  skew  due  to  excessive misalignment 

Excessive surface roughness  Excessive  sliding  of  rolling 

elements 

Check  the  quality/quantity of grease 

Improve  sealing performance 

Check operating conditions Improve  method  of 

assembly and handling 

8.  Indentations: 

Hollows  in  raceway 

surface  produced  by 

solid  foreign  objects 

trapped  or  impacts 

(false brinelling) 

Ingress of solid foreign objects  Trapping of flaked particles  Impacts  due  to  careless 

handling 

Due to impacts loads 

Improve  sealing performance 

Improvement  in  handling and mounting practices 

Check  involved bearing  for flaking  if  dents  produced by metal practices 

Always use clean grease 9.  Electrolytic 

corrosion:  Pits  form 

on  raceway  and 

develop  into  ripples. 

Further  development 

leads  to  corrugated 

surface. 

Electric  current  flowing through raceway 

Create a bypass for electric current 

Insulate the bearing 

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10.  Speckles  and 

Discoloration: 

Surface  luster 

disappears,  and 

surface  becomes 

matted  and  rough. 

Surface  colour  had 

changed.  Surface 

becomes  covered 

with tiny dents. 

Foreign matter 

Improper lubrication 

Temper color by overheating 

Deposition  of  deteriorated grease of surface 

Use  recommended  good quality of grease 

Replacement  of  grease after  recommended interval 

Improper sealing 

11.  Peeling:  Peeling  is  a 

cluster  of  very  small 

spalls.  Peeling  can 

also  include  very 

small  cracks  which 

develop into spalls. 

Ingress of foreign matter 

Improper lubrication 

Foreign matter 

Control  of  surface roughness and dust 

Improve  sealing performance 

Use  only  recommended grease 

12.  Cage  damage:

Breaking  or  wear  of 

cage. 

Excessive moment load 

High‐speed  rotation  or excessive fluctuation of speed 

Trapping of foreign objects  Excessive vibration  Improper mounting 

Investigate  rigidity  of system 

Reconsider  operating conditions 

Improve  method  of assembly and handling 

13.  Spalling:  Score 

accompanying 

seizing.  Mounting 

score  in  axial 

direction.  Scores  on 

roller  and  face  and 

guide  rib‐cyloidal 

scores.  Scratches  in 

spinning direction on 

raceway  surface  and 

rolling  contact 

surfaces. 

Poor  mounting  and  removing practices 

Oil film discontinuation on the contact  surfaces  due  to excessive radial load 

Foreign  object  trapping,  or excessive pre‐load 

Slippage  or  poor  lubrication rolling elements 

Improvement  in mounting and removing procedures 

Improvement  in  operation conditions 

Corrections of pre‐ load  Selection  of  adequate 

lubricant  and  lubrication system  improvement  of sealing efficiency 

14.  Wear:  The  surface 

becomes  worn, 

resulting  in 

Foreign matter in the lubricant 

Insufficient lubrication  Roller skew 

Reconsider  lubricant  and lubrication method 

Improve  sealing 

Page 45 of 50  

dimension  changes. 

Wear  is  often 

accompanied  by 

roughness  and 

damage. 

performance 

Prevent misalignment 

15.  Chipping:  Partial 

chipping  of  inner 

ring,  outer  ring,  or 

rolling elements. 

Trapping of  large  solid  foreign objects 

Impacts or excessive load 

Poor handling   Extreme interference 

Material defective 

Trouble  shooting  and improvements  of  impacts and excessive load 

Improvement in handling 

Improvement  in  sealing characteristics 

16.  Creep:  Surface 

becomes  mirror 

finished  due  to 

slipping  of  the  inner 

and  outer  surfaces. 

Sometimes 

accompanied  by 

discoloration  or 

scuffing. 

Insufficient  interference  of fitting parts 

Insufficient sleeve tightening   Abnormal temperature rise 

Excessive load 

Reconsider interference  Reconsider  operating 

conditions 

Recommended  machining precision  or  shaft  and housing 

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17 BEARING USED IN INDIAN RAILWAYS

(A) CYLINDRICAL ROLLER UNIT (CRU) FOR WDG3A, WDM3A &

WDM3D LOCOMOTIVES

Introduction:

The existing design of cylindrical roller bearings being fitted in high speed diesel and electric locomotives are maintenance intensive requiring:

Frequent periodic attention of maintenance staff

Re-greasing every 6 months

Besides, since the current design does not have the rotating untouched volume sealed off, the whole bearing volume has to be greased at the aforesaid frequency requiring at least 500 gm of grease to be pumped in each axle box during re-greasing as observed in the maintenance sheds. The new design of sealed CRU roller bearings has the rolling volume sealed off through special metallic seals at both the bearing ends with very less radial gap between these seals and loose lip / lipped inner race mounted on the rotating axle. This feature along with a single outer race for two rows of rolling elements per axle box segregates the rotating volume into a completely sealed envelope. Thus, the excess loss of grease is prevented in service requiring a lesser re-greasing quantity (as discussed in the later part of this IB) compared to the conventional ones. Besides, this design feature also helps achieve lesser initial filling quantity of grease in CRUs as compared to the existing conventional bearings.

Also, unlike the conventional cylindrical roller bearings, the internal design of CRUs have lipped inboard inner race. This greatly reduces the possibility of thrower damage while negotiating the sharp curves.

The above merits of CRU bearings shall require lesser human interference in terms of enhancement of period between maintenance schedules and better performance reliability in the field. Thus, the locomotive down time on account of axle box bearing failures can be reduced.

Technical Details:

1. The CRU bearing is basically a double row cylindrical roller bearing and consisting of one Outer Ring, one Lipped Inner Ring, one Plain Inner Ring, 34 approx( nos). (17 Approx.( nos). x 2 Rows) Rollers, two Cages, one loose lip, two seals and 740 grms grease.

2. The CRU Bearing is a completely sealed unit and supplied to Indian Railways in pre-lubricated and ready to mount condition.

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3. Both inner rings and loose lip are held together in the sealed unit by a packing tube. Seals are fitted on both ends to keep the grease inside of this bearing and to prevent ingress of any dust, dirt and contaminants etc. into the bearing.

4. Bearing can withstand a static axle load of 21 tonnes (approximate unsprung axle weight of 1.0 ton) at a maximum speed of 150 Km/hr. It is calculated to reach or exceed under those given conditions the desired L10 life of more then 8.0 million kilometers.

5. CRU bearing are supplied with C4 (0.165 to 0.215 mm) of radial clearances. Loose lip of CRU bearings for end axle and middle axle are designed differently.

(B) CARTRIDGE TAPER ROLLER BARING (CTRB) 6 ½” X 12” CLASS ‘F’ BEARING FOR WDG4 & WDP4 LOCOMOTIVES

Introduction:

GM EMD locomotives fitted with CTRB 6 ½” X 12” Class ‘F’ bearing on the axle journal. This bearing is a self-contained, pre-assembled, pre-adjusted, pre-lubricated completely sealed unit and is applied to or removed from the axle without exposing the bearing elements, seals or lubricants to contamination or damage.

Technical Details:

1. The CTRB consisting of one double cup, two cone assemblies, one spacer, two seal wear rings, two grease seals and 680 gms grease.

2. A spaces with precision ground width is held between the two cone assemblies to achieve the proper axial clearance in an assembled bearing.

3. The CTRB is a completely sealed unit and supplied to Indian Railways in self-contained, pre-assembled, pre-adjusted, pre-lubricated and ready to mount condition.

4. Mounting and dismounting of CTRB to be done by the bearing Puller / Installer on the axle journal with the defined pressing pressure.

5. No need of grease topping up in the bearing in between the schedule maintenance of locomotives.

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18Bearing life Calculation

BEARING LIFE CALCULATION OF M/s BRECO's CTRB 6 1/2" X 12" CLASS 'F' BEARING FOR 5000 H.P. LOCOMOTIVE

Axle load of locomotives W 22.50 tones 220.73 NewtonUnsprung mass of wheel set Wo 1.60 tones 15.70 NewtonDynamic augment factor for CTRB brg. A 1.15 Radial load on one bearing (W-Wo)/2 10.45 tones 102.51 NewtonEquivalent radial load on one bearing Fr = A*(W-W1)/2 12.02 tones 117.89 NewtonEquivalent thrust load on one bearing Fa = 0.20*Fr 2.40 tones 23.58 Newton

Fa/Fr 0.20 e = 1.5 tan a 0.26 0.26Fa/Fr < e X = 1 1.00 Y = 0.45 cot a 2.55 2.55

Equivalent combine load on bearing Pr = XFr + YFa 178.02 Newton

New wheel dia d1 1092.00 mm Condeneming wheel dia d2 1016.00 mm Mean wheel dia D = (d1+d2)/2 1054.00 mm Distance traveled in one revolution pai * D 3311.24 mm 0.00 Km.

Dynamic load rating of bearing Cr 1053.02 Newton 273.00 K N

L10 life without any wheel flange contact L10a = (Cr/Fr)**10/3 1478.57 M Rev. 4.90 M Km

L10 life with wheel flange contact L10b = (Cr/Pr)**10/3 374.33 M Rev. 1.24 M Km

It is assumed that 20% of the time the wheel makes flange contact and 80% of the time when there is no flange contact.

Hence weighted average of L10 life 1/[.8/L10a+.2/L10b] 3.08 M Km

As per RDSO's specification no. MP.0.3600.01 required life is 2.56 M Km

Speed of locomotives V 110.00 Kmph Maximum R.P.M. of bearing for required S 553.67 R.P.M. Speed of locomotives

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R.P.M. of bearing given by the manufacturer 1000.00 R.P.M.

Axle journal diameter d mm Bore dia of bearing 130 / 131.76 mm mm

Axle load of locomotives W 19.500 tones 191.295 NewtonUnsprung mass of wheel set Wo 1.600 tones 15.696 NewtonDynamic augment factor for CTRB brg. A 1.150Radial load on one bearing (W-Wo)/2 8.950 tones 87.800 NewtonEquivalent radial load on one bearing Fr = A*(W-W1)/2 10.293 tones 100.969 NewtonEquivalent thrust load on one bearing Fa = 0.20*Fr 2.059 tones 20.194 Newton

Fa/Fr 0.200e = 1.5 tan a 0.260 0.264Fa/Fr < eX = 1 1.000Y = 0.45 cot a 2.550 2.552

Equivalent combine load on bearing Pr = XFr + YFa 152.464 Newton

New wheel dia d1 1092.000 mmCondeneming wheel dia d2 1016.000 mmMean wheel dia D = (d1+d2)/2 1054.000 mmDistance traveled in one revolution pai * D 3311.239 mm 0.003 Km.

Dynamic load rating of bearing Cr 1047.000 Newton 1.047 K N

L10 life without any wheel flange contact L10a = (Cr/Fr)**10/3 2431.398 M Rev. 8.051 M Km

L10 life with wheel flange contact L10b = (Cr/Pr)**10/3 615.554 M Rev. 2.038 M Km

It is assumed that 20% of the time the wheel makes flange contact and 80% of the timewhen there is no flange contact.

Hence weighted average of L10 life 1/[.8/L10a+.2/L10b] 5.064 M Km

4.500 M Km

Speed of locomotives V 180.000 KmphMaximum R.P.M. of bearing for required S 906.005 R.P.M.Speed of locomotives

R.P.M. of bearing given by the manufacturer 1000.000 R.P.M.

Axle journal diameter D 157.264/ 157.239

mm

Bore dia of bearing d 157.175 (-0.025)

mm

BEARING LIFE CALCULATION OF M/s SKF's TBU 6 1/2" X 12" CLASS 'F' BEARING FOR WDP4 LOCOMOTIVE

As per RDSO's specification no. MP.0.3600.01 required life is

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THANKS