BRENCO_ CTRBM

BRENCO-NBCNBCNBCNBCNBC

ROLLER BEARING MANUAL

CARTRIDGE TAPERED ROLLER BEARINGS

NATIONAL ENGINEERING INDUSTRIES LTD. JAIPUR (INDIA)

BRENCO-NBCNBCNBCNBCNBC INDEX 1. Introduction 3 2. General Information 4 Basic Bearing Assembly 5 Nomenclature and Description of Bearing Parts 6 Application Parts 9 Packing 9 3. Bearing Installation and Removal 10 General Precautions 11 Axle Preparation 12 Mounting Lubricants 13 Equipment for Bearing Installation and Removal 18 Bearing Installation 19 Checking Bearing Installation 21 Lubrication 22 Bearing Removal 23 4. Maintenance and Repair of Cartridge Tapered Roller Bearings 25 Mandatory Instructions and Recommended Practices as Per A.A.R. Manual of Standards 26 Specifications for BRENCO Roller Bearing Maintenance 31 Inspecting Bearing in the Field 32 Inspection of Adapters 34 Reconditioning of CTRBs 36 Bearing Disassembly 37 Inspection of Bearing Components 38 Bearing Damages 42 Service and Maintenance Facility, Offered by N.E.I. 48 Handling of Mounted Wheelsets, During Transit 48

5. General Arrangement Drawings of Cartridge Bearing Assembly 6 x 11 Class ‘E’ 49

2


INTRODUCTION

The first ball and roller bearing manufacturing industry of SouthAsia was established in India in 1947 at Jaipur under the name ofNational Bearing C ompany Ltd., and manufactured thefirst bearing in 1950 under the trademark ‘NBC’. With ever-increasing activities and the working of the factory being diversi-fied to other vital industrial products, the company changedits name toNational Engineering Industries Ltd., in 1958, but the producttrade-mark ‘NBC’ remained unchanged.

National Engineering Industries Ltd. has been pioneer in India forthe manufacture of ball and roller bearings, steel balls and rollerbearing axle boxes to international standards. The first roller1952. NBC bearing are exported to Europe, Egypt and Iran.

The Cartridge Tapered Roller Bearings are manufactured underTechnical collaboration and Licence of BRENCO INC., Petersburg,Virginia, USA who are considered as the world leader for thisproduct. The company has been manufacturing Cartridge TaperedRoller Bearing for the Indian Railway since 1980.

Any specific problem on bearing mounting and maintenance canbe referred to the manufacturer. An expert cell of engineers in thisfield is always at the disposal of our customers.

3


GENERAL INFORMATION

♦ BASIC BEARING ASSEMBLY

♦ NOMENCLATURE AND DESCRIPTION OF BEARING PARTS

♦ APPLICATION PARTS

♦ PACKING

4

BRENCO-NBCNBCNBCNBCNBC GENERAL INFORMATION

BASIC BEARING ASSEMBLY

The BRENCO-NBC Cartridge Tapered Roller Bearing is a self-con-tained, pre-assembled, pre-adjusted, pre-lubricated,completely sealed unit, and is applied to or removed from theaxle without exposing the bearing elements, seals or lubricantsto contamination or damage. The Cartridge Tapered RollerBearings are manufactured in different sizes to fit on axles forall types of new and existing wagons.

Fig. 1a : Bearing Assembly with Narrow Jaw Adapter

Fig. 1b : Exploded View of Cartridge Tapered Roller Bearing

5

BRENCO-NBCNBCNBCNBCNBCNOMENCLATURE AND DESCRIPTION OF BEARING PARTS1. Cone AssemblyThe cone, rollers and cage assembly is perfectly matched to ensureeven wear and long service life. Assembly configuration is similarto standard single row tapered roller bearings. Both cone androllers are manufactured from bearing quality case hardened steel.2. CupThe forged and rolled double cup is machined from bearing qualitycase hardened steel. It has seal grooves located at each end,precision machined to effect a leak- proof fit to provide positivelocking for the grease seals.3. SpacerThe spacer width is precision ground and selected at the factory toachieve proper axial clearance in an assembled bearing. Subsequentadjustment or interchange at the time of installation should not bedone.4. Wear RingThe wear ring is a steel ring, precision ground on the OD to providea smooth, concentric mating surface for the grease seal. The borediameter of the wear ring has an interference fit with the axle.5. Grease SealThe seal is made of special synthetic rubber of superior oilresistance quality, vulcanised with metal casing in a special hotprocess. The primary function of the roller bearing seal is to keepvital lubricating grease inside the bearing and avoid ingress ofwater and foreign particles. This sounds relatively simple. But thebasic fact is that the seal is crucial for the performance of thebearing, which has to operate throughout the span of Bearingperiodic inspection without relubrication in the field.

6

BRENCO-NBCNBCNBCNBCNBCPrimarily the seal is required to perform three functions. Firstly, itshould be held firmly by itself to the counter bore of the bearing(a press-fit). Secondly, rubber lip of the seal must retain itsinterference fit with the rotating wear ring over a life of severalhundred thousand kilometers of operation, despite heat, frictionand dirt, And, thirdly, the seal has to do all this with the leastexpenditure of energy which directly affects the fuel consumption.As the seal rubs on the wear ring, friction or drag is developed,which the locomotive must overcome. In an era of rising fuel costsit is essential to reduce this loss. It is, therefore, necessary to applya light film of grease by finger on the half moon grooves formed onthe inside of the rubber seals, a speciality of Brenco seal design,before mounting the bearing.The BRENCO-NBC Cartridge Roller Bearing are fixed with the bestseal available in the world for reducing fuel consumption andincreasing bearing performance.

6. End CapThe end cap is affixed to the axle by three cap screws and isdesigned for sufficient rigidity to maintain proper cap screwtension, even after years of service. The wear ring should seatproperly inside the recess of end cap to prevent ingress of water.

7. Axle Cap ScrewsThe Axle Cap Screws affix the axle end cap with axle to providesufficient clamping of the bearing on the journal .

8. Locking PlateThe locking plate provides tabs which are bent against the flats ofthe tightened cap screws, thus preventing their undesired turningand subsequent loss of bearing lateral clamp. Two tabs provided foreach cap screw must be bent against the flats of the screw headsfor proper locking of the cap screws.

7


NOMENCLATURE

1. CONE ASSY (CONE 5.GREASE SEAL CAGE & ROLLERS) 6. END CAP2. CUP 7. AXLE CAP SCREW3. SPACER 8. LOCKING PLATE4.WEAR RING 9.BACKING RING

Fig. 2 : NBC Cartridge Bearing Shown in Section

8


9. Backing RingThe Backing Ring positions the bearing, provides a firm base andhelps prevent intrusion of dirt, water and other foreign substances.The backing ring collar must have an interference fit on the axleshoulder and should not rotate by hand-pressure after bearinginstallation.

APPLICATION PARTS

All the parts to be applied to the axle assembly are shown in Fig.2. The Bearing Assembly is pressed on the axle as a completelysealed unit. The axle end cap, cap screws and locking plate areapplied as an assembled unit on the axle journal already fitted withcomplete bearing assembly.

PACKINGSpecial attention has been given to protective packing. Bearingassembly is wrapped in polythene sheet and grease-proof brownpaper. A cardboard packing tube (triangular) is also inserted insidethe bearing to keep the spacer aligned with the cone assemblies.Each bearing assembly is packed in a corrugated box and eachwooden box contains two cartons of bearing assemblies.The Axle end cap & Locking plate, axle cap screws, side frame key,bolt & nut with spring washer & adapter are packed in separatecorrugated boxes, each wooden box contains parts for four bearingassemblies.Bearing should not be removed from this packing until required foractual installation. Packed bearings should be stored in a dry placewhich is well protected from heat, dust & moisture.

A periodic inspection of stored bearings should be made andcorrective measures should be taken if any undersirable conditionis observed.

9


BEARING INSTALLATION ANDREMOVAL

GENERAL PRECAUTIONSAXLE PREPARATIONMOUNTING LUBRICANTSEQUIPMENTS FOR BEARING INSTALLATIONAND REMOVAL

BEARING INSTALLATION CHECKING BEARING INSTALLATION LUBRICATION BEARING REMOVAL

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BEARING INSTALLATION AND REMOVAL GENERAL PRECAUTIONS

Cartridge Tapered Roller Bearings and all other componentsare manufactured with high degree of accuracies and requireutmost care in handling. Without careful handling, the bearingmay fail to fulfill its designed performance even if it is of highestpossible precision grade. The following are some importantcautions that must be borne in mind in installation work toprevent damage before and during mounting: 1 Installation of bearings on the wheel sets should be done inside a separate dust proof shed.2. The installation shop must be clean.3. The bearing assemblies should be stored in a clean and dry

place and should be protected from heat, dust and moistureuntil they are installed on the axle.

4. Bearing assemblies should not be removed from the packageand the protective wrapping should also not be removed untilthe time of application.

5. Use older stock first.6. Pick up/take out the cartons of assembled bearings, wear

rings, backing ring, axle end cap, cap screws and locking plate.7. Remove the bearing assemblies from the carton and place

them on a clean bench adjacent to the wheel and axle assembly.8. Do not remove the cardboard triangular packing from the

bore of the bearing assembly. This cardboard tube is required to hold the conespacer in alignment with the bearing cones

till installation of the bearing assembly on the axle.Removal of this tube can cause the conespacer to slide downand allow the precisely measured quantity of grease to leak out.

11

BRENCO-NBCNBCNBCNBCNBC 9. Bearings and all spare parts must be handled with utmost care and by all means prevented from being hit or dropped.10. Check threads for damage and wear, reject for burrs extending beyond the washer face on the underside of the cap screw head as these will damage the locking plate.11. All the tools required must be ready and conveniently located.

AXLE PREPARATIONIt is of paramount importance that the axles offered for mountingBRENCO-NBC Bearings are thoroughly inspected before mounting thebearings. The following procedure should be employed to ensure optimummounting conditions:

1. Ensure that the axle journal is free from sharp edges,burrs,scratches or high spots and rust spots. Axle and tapped holes shouldbe cleaned. The thread size of the tapped holes must also be checkedwith a master plug gauge to ensure proper locking.

2. Measure the journal at three points along the length and diameter toensure that it is within the allowable tolerance range (Refer SheetNo. 1). Three readings should be noted to arrive at the mean reading.

3. Check axles on shoulders and radii with proper gauge to determinethat finished axle dimensions are within prescribed tolerance toobtain proper fit on axle assembly (Refer Sheet No. 2)

.4. To ensure proper seating of the backing ring, the fillet should be

checked with a fillet gauge (Refer Sheet No.3). In caseof exces-sive fretting of the fillet the axle will have to be machined orscrapped as specified by the dimensional allowances.

5. It may be noted that the bearing cones, wear rings andbacking ring have got an interference fit with the axle journal.

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BRENCO-NBCNBCNBCNBCNBC6. Although the wear ring is

rotated with the axle, yetover a period, the in-boardwear ring seating wears off agroove on the axle due toflexing of the axle. If thedepth of this groove is up to0.002”, then the groove can bepolished with the fine emerypaper to ensure that all sharpcorners or edges areremoved (Refer Sheet No. 1).

MOUNTING LUBRICANTSBefore mounting the bearing, axlemust be coated as below:(a) Journal fillet and portion of axle

between wheel hubs and filletshould be coated with quickdrying anti-rust compound(lead-free).

(b) The bearing seat of the axle should be coated with castor oil, heavy mineral oil (SAE 40 or SAE

50) or a molybdenum disulphide mixture before mounting. White leadis not to be used as it may be detrimental to lubrication grease byacting as an oxidation catalyst. Mounting lubricants must be keptfree from contaminants.

The treatment not only prevent the axle from rusting but alsoallows the bearing assembly an easy push on or pull off duringmounting and dismounting operation without scratching the axlesurface.

Fig. 4

Fig. 3

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METHOD OF MEASURING ROLLER BEARING JOURNALSBearing Seat AreasDial or Digital snap gaugemust be used for checkingjournal diameter accurately.R o t a t e t h e s n a p g a u g earound the journal diameterby 180 degrees within thebear ing seat locat ions toobta in the maximum andminimum journal diameters.The average diameter of eachbear ing seat must be withintolerances. Care must bet a k e n w h e n u s i n gtemperature compensatingspan gauge tha t ro ta t ions p e e d d o e s n o t c r e a t esufficient heat, due to frictionto effect the readings.Thereshall be no abrupt changesor steps over the length of the journals, including tapered end,except journal grooving from inboard seal wear ring ispermissible when repaired as specified below.

BEARING SEATS

Fig. 5

Fig. 5a

Sheet - 1

JOURNALCLASS( Size)

ACCEPTABLE TOLERANCESFOR JOURNAL DIAMETER BEARING SEAT LOCATIONS

MAXIMUM MINIMUM A B C D

E(6x11) 5.6915”

(144.564 mm)

5.6905”

(144.539 mm)

2.88”

(73.0 mm)

5.20”

(132.2mm)

6.56”(

166.7mm)

9.37”

(236.5mm)


Journal Grooving from Inboard Seal Wear RingAs described earlier in this manual, the inboard wear ringcause a groove on the journaldue to axle flexure. Referadjacent sketch (Fig.5b) andtable showing location of thegroove. If the groove in theaxle is not deeper than 0.002”(0.05 mm), it can be repairedby polishing with an abrasivecloth (80 grit or finer). Noabrupt changes or sharpedges are permissible.

Measuring for Upset Journal EndsThe adjustment sketch (Fig. 5c) shows area where upsetting of thejournal occurs. Dial or digitalsnap gauge must be rotatedby 180 degrees around thearea where upsets occur. Inorder for a journal to beacceptable, the diameter inthe area where upsets occurmust never exceed 0.003”(0.080 mm) above maximumtolerance in the adjoiningtable, but may be below theminimum tolerance. Upsetends over 0.003”(0.080 mm)may be corrected.

GROOVE CAUSED BYSEAL WEAR RING

AREA WHERE UPSETS OCCUR

Fig. 5b

Fig. 5c

Sheet - 1

15

BRENCO-NBCNBCNBCNBCNBCROLLER BESRING SEAT LOCATION GAUGE

Note : When reclaiming Journals by plating, plating must not extend into 2” marked area.

Sheet - 2

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FRIEGHT CAR AXLES

JOURNAL CLASS(Size) E (6x11)

A B CDIMENSIONS

D

2.88”

(73.0 mm)

5.20”

(132.2 mm)

6.56”

(166.7 mm)

9.31”

(236.5 mm)


Note: The journal fillet area of a roller bearing axle is critical. To insureproper fit and proper seating of the backing ring on the axle fillet,thejournal fillet gauge must be used to check the fillet radius. If a 0.005” feelergauge can be inserted more than 3/8”down from the dust guard seat,atall points around the axle periphery, the axle fillet must be corrected.

GAUGE FOR CHECKING AXLE FILLET OF ROLLER BEARING AXLESSheet - 3

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Guide TubeCap ScrewsInstalling AdapterConnecting Pin Toolings used for installationPiston Rod Coupling the bearing on axleInstalling Tube- Adapter Ring journal.Installing TubeInstalling Tube Cradles

Pulling ShoeGuide Tube- Same as aboveCap Screws Toolings used for installingInstalling-Adapter as above the bearing from axleConnecting Pin as above journal .Piston Rod Coupling as above

EQUIPMENTS FOR BEARING INSTALLATION AND REMOVAL

Bearing MountingThe bearings are mounted onthe axle journal with aid of aP u l l e r / Inst a l l e r S e r v i c eE q u i p ment, as shown:

The Puller/installer is a self-conta ined por table f ix tureequ ipped w i th a pump fo rinstalling or removing rollerbearings.

The Puller/ Installer Service Equipment have the following toolings:

Fig. 6

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BRENCO-NBCNBCNBCNBCNBC BEARING INSTALLATION

Af ter coat ing the ax le asmentioned, the bearing is slippedo v e r t h e g u i d e t u b e ,automatical ly ejecting thecardboard inser t . As thecardboard insert is e.jectedthe wear ring should be held inplace by hand so that it willnot be pushed from the seal.

If the wear ring slips out of theassembly it must be insertedinto the enclosure seal correctlyand carefully pushing chamferedend first.

Do not insert any tool or otherinstrument between the sealelement lips and wear ring. Thismay damage the seal elementlips or scratch the wear ringresulting in bearing lubricantleakage.

PRESSING BEARING ASSEMBLIES ON AXLEWhen the bearing is ready formounting, care should be takento align the bearing, axle and themounting press on the samecenterline. Fai lure to do thiscould result in damage to the

Fig. 7

Fig. 8

Fig. 9

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bearing or axle. The entirebearing (except end cap, lockingplate &cap screws) should bemounted all at one time. Duringinstallation of the bearing, pressforce is applied on the out boardwear ring face only.The bearing will requireapproximately 10 to 16 tons tobe pressed in t o the place due tointerference fits betweenj o u r n a l a n d b e a r i n gcompone nts. The press forceshould be allowed to climb to“Seating Pressure” of 50 +

5 tons and held for 5 seconds to fully seat the bearing. Thisseatin g pressure e n sure thatthe bearing is fully seatedagainst the axle fillet.

After the mounting procedure is complete, bearing assemblymust be rotated by hand to ensure freedom for movement. Thebearing wil l turn freely feeling the grip of the rubber seals. Ifthe bearing fails to rotate by hand it is to be removed from theaxle for re-inspection to determine the cause.Apply the end cap, locking plate and cap screws. The capscrews should rotate freely into the threads until they are snugaga ins t lock ing p la te . Tigh ten the cap screws to therecommended torque. Repeat the torque wrench passes untilno further screw movement is detected. A minimum of 2 passesis recommended. Bend the tabs of the locking plate against

Fig. 10

Fig. 11

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BRENCO-NBCNBCNBCNBCNBCsides of the bolt head using adjustable rib joint pliers as shown(Refer Fig.9, 10 & 11).New recommended values of various mounting parameters forCartridge Tapered Roller Brg 6 x 11Class “E” are as below:

.

CHECKING BEARING INSTALLATIONRotate the bearing assembly by hand to make sure that it willturn freely feeling the grip of the rubber seals.New bearing assemblies are preadjusted at the factory. No adjust-ment is necessary at installation to check lateral end play.In case of brgs.a and /or old journals it is essential tocheck lateral play in all assemblies.

Apply a dial indicator gauge having a V-shaped magnetic baseto the outside diameter of the bearing and position the feeleragainst the wheel hub face. Push the bearing in the directionof wheel hub and pull it in the opposite direction to measurethe bearing lateral play which should be between 0.001” and0.015”(0.03 mm & 0.38 mm ).Note: If a brg. rotates freely by hand but indicates less than 0.001Lateral on Dial indicator, the application is satisfactory for service

Final Seating Pressure(Hold for 5 seconds)

Cap Screw size

50±5 tons

1”-8 UNC Cap Screw Torque (Minimum 2 passes are recommended )

40 Kg-m(290 foot-pound)

Torque Wrench Accuracy 4% Mounted bearing lateral play (Apply hand pressure only)

0.001” to 0.015” (0.03 mm to 0.38 mm)

+_

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BRENCO-NBCNBCNBCNBCNBC LUBRICATIONAll BRENCO-NBC Cartridge Tapered Roller Bearings are pre-lubricated at the factory. No additional lubricant is to be addedafter the bearing is applied to the axle. Only approved grease andthe correct calibrated quantity must be used when greasingbearing assemblies.

Excessive quantity of grease in a bearing assembly will increase thechurning action and cause a rise in temperature. This will resultin thinning of the grease and consequent leakage and may be

It is essential that the seal element lips are lubricated before theseal wear rings are placed in position, but care should be exercisednot to apply more than a film of grease to the element lips.

Type of grease recommended :ARAPAN RB-320(imported), servoGrease RBI (IOC) & Balmerol Multigrease RB (Balmer Lawrie)Quantity of grease per bearing Assembly as below.

(Size 6 x 11 Class “E”)

Distribution of grease inside the bearing assembly is as below :

Grease Quantity applied 4 oz. to Single Cone Assembly (115 Grams Approx.)

Grease Quantity between 8 oz. Cone Assemblies (around spacer) (225 Grams Approx.)

confused with symptoms of a worn-out element.

Total Grease Quantity 16 oz. 1 oz. per Bearing (453.6 Grams )

The measured quantity of grease is filled by a special greasingfixture. In the workshop the same can be checked by weighing thegrease-filled bearing on an accurate dial type weighing machine.

+_

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BRENCO-NBCNBCNBCNBCNBC BEARING REMOVALThe procedure is reverse of bearing mounting.

Bearing are normally withdrawn from the axle only when wheelsare removed or during POH of wagons.

In order to remove BRENCO-NBC Tapered Roller Bearing, firstremove the side frame key from the pedestal opening and lift theadapter assembly off the axles. The bearing assemly emovedby the portable Rail-Road Axle Journal Roller Bearing Puller-Fig.6. Bearings should never be dropped on the floor. Slide off on asupporting stand of suitable height.

After the bogie frame and adapter have been removed, thoroughlyclean the outside of bearing assembly. Bend the tabs the lockingplate away from the flat of the cap screw heads. Unscrew the axlecap screws, remove the axle end cap, axle cap screws and lockingplate. It may be necessary to tap end cap lightly for removal.

When the bearing assembly is removed from the guide tube, a tubesimilar to the cardboard packing tube should be insertedn boreof bearing assembly to hold the internal bearing parts in place.Particular attention should be given to keep the wear rings inposition inside the grease seals.BEARING REMOVAL USING PORTABLE ROLLERBEARING PULLERWhen bearing Assembly is to be removed, the gu ide tube is tobe fastened to the end of the axle (Fig.12).Insert the guide tube adapter in the threaded hole in the guidetube (Fig. 13). This adapter is retained by a spring-loaded balland is not threaded.Selected the pulling shoe adapter insert for the size of thebearing (6x11 Class “E”) to be removed and fasten it to thepulling shoe (Fig. 14).

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Place the forcing plug adapterin the ram head as shown inFig.15.

Position the bearing removalf i x t u r e o n t h e b e a r i n gassembly to be removed b ytilting the pulling frame asshown in Fig.16.Make sure that the fixture is in

alignment with the axle and hold the pulling shoe down in positionbehind the backing ring until initial pressure has been applied,extend the ram to remove the bearing from the axle.

Fig. 12 Fig. 15

Fig. 13 Fig. 16

Fig. 14

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MAINTENANCE AND REPAIR OFCARTRIDGE TAPERED ROLLERBEARINGS

§ MANDATORY INSTRUCTIONS AND RECOMMENDED PER A.A.R.

MANUAL OF STANDARDS

§ SPECIFICATIONS FOR BRENCO ROLLER BEARING MAINTENANCE

§ INSPECTING BEARING IN THE FIELD

§ INSPECTION OF ADAPTERS

§ RECONDITIONING OF CTRB

§ BEARING DISASSEMBLY

§ INSPECTION OF BEARING COMPONENTS

§ BEARING DAMAGES

§ SERVICE AND MAINTENANCE FACILITIES OFFERED BY N.E.I.

MANDATORY INSTRUCTIONS ANDR E C O M M E N D E D P R A C T I C E P E R A . A . R .MANUAL OF STANDARDS

SPECIFICATIONS FOR BRENCO ROLLERBEARING MAINTENANCE

INSPECTING BEARING IN THE FIELD

INSPECTION OF ADAPTERS

RECONDITIONING OF CTRB

BEARING DISASSEMBLY

INSPECTION OF BEARING COMPONENTS

BEARING DAMAGES

SERVICE AND MAINTENANCE FACILITIESOFFERED BY N.E.I.

H A N D L I N G O F M O U N T E D W H E E L S E T SDURING TRANSIT

25

BRENCO-NBCNBCNBCNBCNBCMANDATORY INSTRUCTIONS AND RECOMMENDEDPRACTICES AS PER A.A.R. MANUAL OF STANDARDS RULES

1.1 To insure trouble free operation, interchange railways cars equippedwith roller bearings must be maintained in accordance withA.A.R. Manual of Standards Sec. H-Part II except where otherwiseauthorised by the A.A.R. Inspection and servicing at terminalsand all repair tracks as well as in the roller bearing shops arenecessary and must be performed by qualified personnal.

1.2 All shops performing repairs to roller bearings for interchangeoperations must meet the requirements totally as per A.A.R.

1.3 Roller bearing adapters are designed to properly distribute theload on the bearing. They must be maintained to ensure rollerbearing operating life and eliminate possibil i ty of failures.Inspection procedures and wear limits for roller bearing adaptersare covered in Field Manual Rule 37.

1.4 New roller bearing must conform to the latest revised A.A.R.specification M-934.

1.5 New roller bearing adapters must conform to the latest revisedA.A.R. Specification M-924.

1.6 Due to the numerous design of Housing Type Roller Bearings,maintenance requirements should be made in accordance withinstructions from roller bearing manufacturers.

1.7 Where ques t ions arise in connection with failures or otherconditions, manufacturer’s representative should be consultedwith respect to his product.

1.8 When cars equipped with roller bearing units are involved in fire,high water and other similar incidents that could possibly damageroller bearings, the following applies:

The wheel assemblies must be removed from the car or cars,assemblies inspected in accordance with the Wheel and Axle

26

BRENCO-NBCNBCNBCNBCNBCManual, and the roller bearings dismantled and examined for defects inaccordance with the Roller Baring Manual.

1.8.1 When cars equipped with roller bearing units are involved in a fire,the heat may be sufficient to temper the bearing ring and / ordestroy the lubricant and / or seals. Special examination is requiredin such instances. Similar damage may also occur in car thawingoperations, particularly where open flames are employed. Wheelassemblies a re to be inspected in accordance with Wheel and AxleManual and roller bearings dismantled and examined for defectsin accordance with Roller Bearing Manual with special attentionbeing given to determine if excessive heat has affected any of thebearing parts.

1.8.2 Roller bearings used in interchange service are vulnerable towater in that it affects the efficiency of the lubricant, and alsoresults in water etching of the bearing parts. Therefore, whenroller bearing are operated in high water condition that resultsin water churning up around the seal, or are standing in highwaters where the bearing are partially or completely submerged,moisture will enter the interior of the bearing. When this occurs,wheels are to be removed as soon as possible. Wheel assembliesare to be inspected in accordance with Wheel and Axle Manualand roller bearings dismantled and examined for defects inaccordance with Roller Bearing Manual.

1.8.3 When cleaning cars or trucks equipped with roller bearings careshould be exercised not to direct steam jet or water jet spraytoward seal or vents of roller bearings.

1.8.4 Electrical current must never be passed through roller bearingsas it may cause arcing within the bearing causing damage. Allwelding shall be done with ground cable attached so that thecircuit formed shall not allow electrical current to flow throughroller bearings.

1.8.5 Heating or cutting torch when used around roller bearingsmust never have heat directed on any portion of the rollerbearing assembly. Care should be taken that cutting fragments are notdirected towards the roller bearing assembly. Heating torch mustnever be used to heat lubricant fitting or plug for removal.

27

BRENCO-NBCNBCNBCNBCNBC1.8.6 When bearing failure occurs due to overheating, the outers cup

must be painted with a two-inch stripe of white paint. Thecomplete roller wheel assembly, with adapter at over-heatedbearing, must be properly identified giving car number and initial,date and location failed, lubrication date, detector millimeterreading if available, and shipped to the point designated by therespective railroad to determine cause of failure. Adapter shouldbe marked to indicate which end was inboard. Manufacturermust be requested to send a service representative to make a jointinspection with railroad representative to determine cause offailure. A roller bearing failure report ( as required by the A.A.R.)must be used to record this joint inspection.

1.8.7 Plating, metal spray, welding or any other methods of building upbearing parts is prohibited, except plating is permissible bybearing manufacturers on all surface except raceway and rollersurfaces and the seal wear ring outer diameter.

1.8.8 Abrasive cleaning materials (sandblasting, grit blasting etc.) mustnever be used to clean outer rings, rollers, inner rings, thrustcarrying end caps and backing rings and seals. However, externalsurfaces of outer rings and other parts subject to corrosion andpaint accumulation may be cleaned by use of abrasive materialsto expose possible damage. All parts treated in this manner mustbe cleaned before reuse.

1.8.9 Bearing parts of different roller bearing manufacturers mustnever be mixed nor interchanged in the same assembly, except asdesignated by the A.A.R. in Section 7 of A.A.R. Manual ofStandards sec. H-Part II. This restriction also applies to bearingmade by the same bearing manufacturer which have differentA.A.R. approval numbers (see manufacturer’s specification sheet).

1.8.10 Waste must not be used to clean roller bearings. Clean towels free fromlint must be used.

1.9 If a wheelset is derailed, refer to Field Manual Rule 36, Section A,for handling instructions.

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The following are the recommended practices for long life andtrouble-free operation of Cartidge Tapered Roller bearings:

1. It is of utmost importance that the repairs or rebuilding of cone assembly be performed only by the manufacturers themselves on their own bearings.

.

RECOMMENDED PRACTICES

This is because of the fact that the basic design of Tape red Roller Bearing warrants the conicities of all tapered components

geometric accuracy is not achieved, the bearing will fail prematurely. This is all the more important in a compound bearing like Cartridge Assembly with a double track cup. Further the rollers, cones and cups always have matched angles keeping the Apex Point in consideration. There can be No interchangeability of parts or races or assembly possible with different makes of bearings.

3 Heating or cutting torch when used for repair of wagons aroundthe roller bearings must never have heat directed on any portion ofthe roller bearing assembly. Care should be taken that cuttingfragment are not directed towards the roller bearing assembly.

While repairing the wagons by electric arc welding, the earthingcable must be connected near the portion being welded. Thisis necessary to avoid passing of electric current through theroller bearing and its possible damage (Electric Corrosion).

to meet at one point , known as ‘Apex’ point. In case the

2 The assembly of the cartridge tapered roller bea r ings also requires very careful calculations so that the bench lateral play

in each bearing is controlled within a to le rance of 0.020” to0.026” in unmounted condition. This necessitates the use oflateral play checking fixtures and precision graded spacers.

29


POH or during the time of wheel-changing, the grease sealshave to be replaced. The mounting of grease seals requires thepressing fixture for properly mounting the seals.

It is important that specified amount of grease is filled in thebearings for which special greasing fixture is recommended.Excess amount of grease may result in failure of bearings dueto generation of excessive heat or pressure that can pop out ofthe grease seals.

It is, therefore,. recommended that unless a complete facility forcleaning, re-greasing and reassembly of the cartridge bearingis installed, repairs cannot be undertaken at railway workshops.Therefore, the bearings must be returned to the manufacturerfor inspection and repairs.

4. Whenever bearings are pulled out for inspection at the time of

30


BEARING CLASS (SIZE) B(41\4 x 8) F(61/2 x 12)E(6 x 11)D(51/2 x 10) G(7 x 12)C (5 x 9)

CONE PART NO.MAX BORE OUT-OF-ROUND

‘A’ AVG ID NOT TO EXCEED

HM 120848 HM 124626 HM 129848 HM 133444HM 127446 HM 136948

003” FOR ALL SIZE BUT AVERAGEMUST EXCEED ‘A’ LIMIT

5.1885” 6.1885” 7.0010”5.6885”4.6885”4.0010”

CAGE INSPECTION‘B’ POCKET SIDE CLEARANCE

PLACE CONE ASSEMBLY ON BACK FACE AND USE FILLER GAGES

LESS THEN 060” BETWEEN ROLLER AND CAGE BRIDGE

HM 120817XD

807 907

‘D’ C’BORE NOT TO EXCEED

MAX C’BORE OUT-OF-RND

‘C’ MINIMUM O.D.CUP PART NO.

‘D’ C’BORE MINIMUM

HM 124618XD HM 127415XD HM 129814XD HM 133416XD HM 136916XD6.4900” 7.6775” 8.175” 8.675” 9.925” 10.863”

005” FOR ALL SIZES BUT AVERAGE MUST MEET ‘D’ LIMITS

6.0665” 7.1915” 7.754” 8.254” 9.379” 10.279”

10.2709.370”8.245”7.745”7.1850”6.0600’

GREASE SEAL PART NO.

CONE SPACER PART NO.

1007 1107 1207 1307

REPLACE WITH NEW AAR APPROVED INTERCHANGE SEALS

HM 120848XA HM 124646XA HM 127446XA HM 129848 HM 133444XA HM 136948XA

.018” to .024” Hand Lateralor .021” to .027” Power Lateral

.020 “ to .026” Hand Lateralor .023” to .029” Power Lateral‘E’ WIDTH SELECTION

MUST PROVIDE

WEAR RING PART NO.

BACKING RING PART NO.

906 1006 1106 1206 1306

‘F ‘ WEAR LIMIT SEAL LIP CONTECT PATH LESS THAN 005” DEEP

PROVIDE TIGHT FIGHT ON WEAR RING

AREA NOT GALLED OR PITTED USE RADIUS GAGE AS SPECIFIED IN RBM

IF PRESENT,REPLACE VENT WITH PLUG OR SEALANT

806

815N 915N 1015N 1115 1215 1315F‘G’ COUNTERBORE

‘H’ FILLET CONTACT

‘I’ VENT FITTING

‘J’ I.D.MAX.AVG.(FITTED) N.A. N.A. N.A. 7.030” 7.530” 7.998”

END CAP PART NO. 811 911 1011 1111 1211 1311NO CRACKS,BREAKAGE,WEAR,OR DISTORTION

IF PRESENT,REPLACE WITH NON -REMOVABLE PLUG

NOTE RBM FIG 3.14 FOR FLOW THRU GREASING FROM BOTH SIDES

INSPECTION

‘K’ LUBE FITTING

GREASE WEIGHT OZ EACH CONE ASSEMBLY

SPACER

2 3 4 4. 6 8

16

32

12

24

8

1616

86

128

4

TOTAL +

- 1 OUNCE

ALL PARTS OF BRENCO ROLLER BEARINGS ARE TO BE MAINTAINED INACCORDANCE WITHABOVE SPECIFICATIONS,ASSOCIATION OF AMERICAN RAILROADS (AAR)REQUIREMENTS IN AAR

ROLLER BEARING MANUAL(RBM) AND AAR MANUAL OF STANDARDS AND RECOMMENDED PRACTICES.BASE PART NO SHOWN ONLY. SEE INTERCHANGE LISTING FOR A COMPLETE LIST.

*INTERCHANGEABLE WITH AAR APPROVAL NO 26 BEARING PART DO NOT INTERCHANGE WITH AAR APPROVAL NO 13 BEARING PART

BRANCO, INC. P.O. BOX 389, PETERSBURG, VIRGINIA 23804

ENGINEERING DWG NO. CP- 200 040 REV. M.,7-13-94

Specifications for BRENCO Roller Bearing Maintenance

31

BRENCO-NBCNBCNBCNBCNBC INSPECTING BEARING IN THE FIELD

While inspecting the bearing in service, extreme care must beexercised to avoid serious consequences. Bearing must be checkedfor the followings:

(a) Abnormal NoiseWhen the bearing rotates try to listen for any unusual/ abnormalnoise or grinding.

(b)Running TemperatureCheck operating temperature of the bearing by touching theadapter or underside of the bearing cup with bare hands immediatelyafter the vehicle is halted. If it is found impossible to hold the handfor a few seconds on the adapter or the cup it means that thebearing is running hot. Cross check the bearing temperature with

temperature indicating crayons suitable for 90 degree centigrade. Any alternate method can also be used to find out bearing temperature. If bearing temperature is more than 90 degree centigrades the bearings should be removed from the service.

(c) Visible DamagesVisually inspect the bearing for defects like broken cup, loose ordamaged grease seals, broken adapters, missing cap screws,broken /distorted end cap, broken locking plate. Check for loosebacking rings, missing side frame key. Any of these conditions arereasons for bearing removal.

Inspect bearing for displaced adapters. Displaced adapter causenon-uniform loading of the bearing and result into prematurebearing failure due to pinching/point loading of the cup. Adapterdisplacement can result from severe vehicle abuse, wagon tripling,lack of care at the time of bogie assembly, high speed impactcoupling with side frame key absent. If an adapter is found

(D) Displaced Adapters

32

BRENCO-NBCNBCNBCNBCNBCdisplaced the bearing must be removed from the service immediatelyand inspected thoroughly.(e) Grease LeakageDuring service, some grease leakage is normal and comes from thepurging of seal pre-lube and the relieving of internal bearingpressures. This should NOT be wiped away. This will “set up’ andstop further leakage. The apparent amount of grease may be fairlylarge, but this is usually only a small amount of grease mixed withcontaminants. If the purging continues to the point of coating asignificant amount of the surrounding areas, then bearingmanufacturers should be contact.

33

BRENCO-NBCNBCNBCNBCNBCINSPECTION OF ADAPTERS

Adapter provides a means to properly distribute the load from theSide frame on to the bearing cup exterior. Top of the adapter hasa crown running fore-aft which allows misalignment betweenjournal and side frame. Some of this misalignment may occurwhen axle deflects under load. It also has a groove running inboardto outboard which helps to distribute the load over as much of thecup exterior as possible. One unique feature of the adapter is thatit allows the cup to “creep”. As track imperfections are crossed theload between cup and adapter may briefly disappear due to systemdynamics. This will allow the cup to turn in the adapter a little bitcalled creep. Over the bearing’s life it may make several completerevolutions in the adapters. This allows the fatigue wear to bespread over the entire cup instead of being isolated to oneparticular area.Due to the above important function, it is very essential thatadapters are checked thoroughly using specified gauges at thetime of inspection before they are put back to service.

Refer AAR Specification M-924 for detailed information on gauges, acceptable limits and method of measurements.

• Broken or cracked adapters must be scrapped. Repairing of adapters by welding / brazing is not permitted. • Warped, distorted or twisted adapters must be scrapped. To check distortions, place the adapters on cup and it must seat firmly on the cup without rocking or pinching when hand pressure is applied.• prevent proper seating in side frame on the adapter or proper seating on cup , adapters must be scrapped.• If the crown portion of the adapters has fully worn (up to the

crown relief groove) adapters must be replaced by new adapters.

When adapters are worn to such an external that ridges or grooves

34

BRENCO-NBCNBCNBCNBCNBCThrust shoulders of the adapters may show wear due to contactwith ends of the cup. When such groove exceeds 0.7 mm indepth at any point the adapters must be scrapped.

Adapter machined relief must have 1/32” (0.8 mm) or greaterdepth.

Check full bearing s e a t s of the adapter for wear by gauge.Excessively worn out adapters must be scrapped.

Adapters which are worn on one side between thrust lugs dueto braking reaction, but otherwise satisfactory must be reversedin direction when reapplied into the pedestal frame. When bothsides shows wear more than 1/8” (3 mm) do not reuse theadapters.

Adapters must be checked for proper fit on the cup and in the pedestal before placing in the truck frame.

35

BRENCO-NBCNBCNBCNBCNBCRECONDITIONING OF CARTRIDGE TAPERED ROLLER

BEARINGWhenever Cartridge Tapered Roller Bearing that has been inservice is removed from the axle it must be reconditioned beforereapplication. Reconditioning process includes bearingdisassembly, cleaning, inspection and repair if necessary and re-assembly of roller bearing. Roller bearing reconditioning should beconfined in a separate shop or enclosure within a building. Tools, devices and cleaning facilities must be used which will rehabilitateroller bearings to serviceable standards. Following are themandatory requirements for bearing reconditioning shop-

Roller bearing reconditioning shop should be cleaned at alltimes.All work areas, benches, tools and gauges must be kept clean.Roller bearing parts that are not used immediately must beprotected from corrosion and dirt.It is also important that all tools, gauges, masters and torque

wrenches must be calibrated regularly.

36

BRENCO-NBCNBCNBCNBCNBC BEARING DISASSEMBLYFor disassembly of the Cartridge Tapered Roller Bearing steps to

be followed are listed below-1. Remove backing ring, wear rings and excess grease from the bearing and take the bearing for disassembly bench work.2. Remove the grease seals from the cup using suitable tools(pry

bar or with the help of seal dismounting jig). Care must be takento prevent unnecessary damage to the bearing while removingseals. Used grease seals must be scrapped.

3. Remove both cone-assemblies and spacer from the cup.4. All parts disassembled from he bearing must be pre-cleaned by removing residual grease as much as possible before wash cleaning.5. Wash the bearing with the help of suitable media to remove all lubricants and dirt. Bearing washing may be accomplish through

automatic cleaners, washers, agitators or spray systems. The cleaning media must not be harmful to roller bearing parts. Washing media must be filtered before reuse.6. Backing ring and end cap must be cleaned separately.

7. Take bearing parts for visual and dimensional inspection.8. Do not intermix roller bearing parts of different make.

37

BRENCO-NBCNBCNBCNBCNBC INSPECTION OF BEARING COMPONENTS

After through cleaning take bearing parts to the inspection area.The inspection area must be well lighted and clean. Use bearingmanufacturer’s specification for sizes and wear limits for all

bearing assembly component parts during inspection End Cap

Inspect the end cap for surface damage, cracks, breakage, wearor distortion. Any other condition that would affect properseating of the end cap on wear ring face must be corrected if

possible otherwise defective end cap is to be rejected.

Backing RingCheck the backing ring visually for crack, distortion, excessivecorrosion, wear and heavy pitting and scrap backing ringshaving such defects.Ensure that counter bore of the backing ring must provide apress fit on wear ring.Breakout diameter of the backing ring shall not exceed the limitspecified in “Specifications for Brenco Roller Bearing Maintenance”attached in this manual.Check backing ring fillet radius with 1.5” (38.1 mm) radiusgauge.It must be noted that old design backing ring with vent holemust not be allowed for further service without plugging thevent hole. From Aug.1992 onwards vent hole was eliminatedbecause the vent hole was found as a potential reason foringress of water and corrosion of journal. Vent hole and vent

plug have now been eliminated.Cap ScrewsCheck cap screw thread for damage and wear. Check cap screw

body for elongation. Reject cap screws having burrs extending

38

BRENCO-NBCNBCNBCNBCNBCbeyond washer face on the under side of cap screw head as this willdamage the locking plate. Screw threads must be in clean condition.If any defect is found cap screw must be rejected. Cap screws mustbe lubricated before reapplication.

Grease SealsUsed grease seals must be scrapped and must be replaced withnew grease seals only. Every time bearings are opened for inspectionnew grease seals must be used while re-assembly of the bearing.

SpacerSpacers must be visually examined for cracks, nicks and burrs.Cracked spacer must be scrapped. Nicks and burrs on the endfaces of spacers must be stone smooth. Grade all spacers for widthsize as width selection of the spacer is done to provide bench lateralplay 0.020” (0.51 mm) to 0.026” (0.66 mm)Refer “Specifications for Brenco Roller Bearing Maintenance” attachedin this manual for further information.

Cone AssemblyInspect the raceways visually for staining , acid etching, corrosion,pitting, heat discoloration, false brinelling and spalling (Flaking).Cone assembly should also be checked for indentation, electricburns, crack. Use suitable well lit stand for the inspection of thecone assembly and turn cage and rollers while examination of coneassembly. A feeler gauge probe can also be used to feel surfaceroughness of the rolling surface of cone.

In addition to the above all cone assemblies must be checked forfollowing dimensions as specified in “Specifications for BrencoRoller Bearing Maintenance”-

Cone bore diameter and bore out of roundness on both sides at a distance of 10 to 13 mm from each face and it must be within

39

BRENCO-NBCNBCNBCNBCNBC specified limit. It is recommended that a dial type indicator is used for measuring cone bore diameter.

Measure the gap between small flange of cone and cage inside diameter at two diametrically opposite locations using two feeler gauges. The sum of two readings should not exceed 0.090” (2.3 mm).

Check cage pocket clearance with feeler gauge and it should be within 0.060” (1.5 mm)

Scrap cone assembly that does not conform to the dimension /defects discussed above. Refer Manufacturers specification forfurther information.

CupAll cups should be checked for wear patterns seen on the cup outside diameter not only because of its importance on the life of thebearing but also as it reveals excessive wear of the adapter.

The fig. 17 shows normal wear bands present on cup OD generatedfrom a serviceable adapter.

Wear bands formed due to excessively worn out adapter areillustrated in the Fig 18. In case of fully worn out adapter the cupstarts contacting the adapter at the ends also. Worn out adapters

Normal wear bandsDeep relief

Chamfer

Fig. 1740


must be scrapped. Displaced adapters also form two distinguishedmarks on the cup out side diameters. And such cups must beexamined carefully for spalls being generated on raceways underthe adapter contact areas.Visually examine cup raceways for staining, acid etching, corrosion,pitting, heat discoloration, false brinelling and spalling (Flaking) ,fragment indentation, electric burns, crack etc.Following dimensional checks are applicable for cartridge bearingcup-. Measure cup outside diameter and out of roundness at adapter contact areas. Cups having outside diameter below the specified limits and out of roundness more than the specified limits must be rejected.. Check cup counter bore diameters and out of roundness on both ends using dial indicator.For additional information refer sheet showing “Specifications forRoller Bearing Maintenance” in this manual.NoteIn case bearing components requires regrinding of operating surfaces,it must be done by original bearing manufacture only. Parts mustbe returned to the bearing manufacturer.

Normal wear band width

Abnormalextension of

wear band

Indication ofcontact withshoulder

Contact due toexcessive wearof adapter

Fig. 18

41

BRENCO-NBCNBCNBCNBCNBC BEARING DAMAGESFollowing are some of the most common damages found incartridge tapered roller bearing at the time of reconditioning andinspection in bearing shop. If a bearing has failed it is recommendedthat the reason for bearing failure should be investigated so thatcorrective actions may be taken.

The examples shown in this section are intended as visual guidesfor better explanation only and are NOT to be referred as substituteto the rules specified by the AAR (Associat ion of AmericanRailroad). For further detail please see AAR roller bearing manualSection H Part-II.

FLAKING / SPALLINGMinute surface cracks are the first visible indication that flaking onthe rolling surface has started. It spreads up due to increase instresses at edges of the spall. Metal fragments those separatedfrom the spalled area are carried in lubricant and causing increasein size of the flaked area.

There are so many reasons for flaking e.g. metal fatigue, abnormalloading conditions, displaced adapters, grease contamination,lack of lubricant, impact load on the bearing etc.

Flaked / Spalled Cone AssemblyIf the raceway of cone or a roller surface is spalled, the completecone assembly should be scrapped. However small pinhead sizespalls on the cone raceway 3/32” x 3/32” (2.4 mm x 2.4 mm) areacceptable as exception for further service.

Flaked / Spalled CupAs specified in AAR Roller Bearing Manual, incipient spalls on cupor cone can be repaired using pencil grinder and fine abrasivewheel to grind away loose material and to remove sharp edges of the

42

BRENCO-NBCNBCNBCNBCNBCspall. It is recommended toU s e s p a l l l i m i t g a u g e t ode t e r m i n e m a x i m u mRepairable spall size.

Not more than two spalls ofmax imum s i ze 3 / 8 ” x 3 /8 ”(10 mm x 10 mm) should berepaired in a 2” (50 mm)circumferential section of theraceway and not more thanfour spa l ls 1 /16” x 1 /16”(1.5 mm x 1.5 mm) or less inan equally large section. Abridge of 3/16” (5 mm) mustbe left between two spalls aftergr inding, except where thespal ls can be run togetherwi t h i n t h e m a x i m u mdimension if one spall 3/8” x3/8” (10 mm x 10 mm). Themaximum acceptable depth forspall is 1/8 ” (3 mm) . I f t hespall size is more than 3/8” x3/8” (10 mm x 10 mm) the cupmust be rejected.

Fig. 19Incipient spall acceptable after repair

Fig. 20Incipient spall acceptable after repair

Fig. 21Large Spall (Rejectable)

43


BRINELLINGBr i ne l l i ng a re t he su r f aceindentation marks in racewaysmade by roller under impactload. In other words, whenrollers are forced into surface ofeither raceway while the bearingwas subjected to heavy impactloading beyond it’s capacity.

If the length of a faint brinellmark is less than half the widthof raceway and if its width atthe widest point does not exceed5/32” (4 m m ) t h e p a r t i sacceptable for service. If thelength of the faint brinell markis more than half the width ofraceway and it’s width at widestpoint does not exceed 3/32”(2.4 mm) the part is satisfactoryfor further service. Any numberof brinell marks is permissible.Is the brinell mark exceed eitherof the limitations the cup mustbe rejected. Also if the part hasheavy brinell marks havinglength more than half raceway

Width the ring must be rejected.

It is recommended to use “Brinell width and Spall Limit Gauge “ to check width of the brinell mark.

Fig. 22 : Acceptable Brinelling



Fig. 25 : Brinelling not Acceptable

44

BRENCO-NBCNBCNBCNBCNBCSMEARING & PEELINGSmearing is transfer of metal fromone surface to another as a resultof galling. This may be due tosliding of rollers on raceways dueto adverse lubricating condition. Ifthe cup, cone or rollers has veryshallow smearing less than 0.001”(0 . 025 mm) dep th i t may bereturned to service after polishing.

Peeling is the condition caused by minute particles of metal peeling away from original metal surface. Cup, cone & rol lers having very shallow peel ing depth 0.001” (0 .025 mm)or less on rolling surface may be returned to service.

STAIN DISCOLORATION, CORROSION PITTING & RUST The adjacent figures shows surface corrosion damage on raceways and rollers, of three different intensities. Stain discoloration are

caused by etching due to moisture or acidity in the lubricant.Superficial stains & discoloration having no depth and which canbe removed by 180 grit abrasive or finer or wire brush areacceptable after polishing. Care should be taken that metal is notremoved from rolling surfaces.

Corrosion pitting or rusting(black corrosion lines or pit marks)which has advanced to severe pitting must be repaired by polishingraceways and rollers.Slight pitting after polishing is acceptable.

Fig. 26 : Smearing-Acceptableafter Polishing

Fig. 27 : Peeling-Acceptable

45


The cup or cone assembly which can not be repaired satisfactorilyby polishing must be rejected.

HEAT DISCOLORATIONColor from faint straw to dark blue may be indication of overheatingof bearing. Heat discoloration should not be confused with lubricantstains or phosphate coating. If there is evidence of overheating,parts must be rejected.

FRAGMENT INDENTATIONSFragment indentat ions in thebearing may be caused due tolubricant contamination e.g. dirt,dirt and spalling debris passingover rolling surfaces. Bearing partssh o u l d n o t b e r e j e c t e d f o rindentation marks present onraceways unless the damage isSuch tha t roughness can bedetected when the bearing can berotated by hand.

Fig. 28Stains & discolorationhaving no depth

Fig. 29Superficial water or

acid etching

Fig. 30Severe corrosion

pitting

Fig. 31

46


ELECTRIC BURNSSurface damage from passage ofelectric current through bearingcause electric burns. These arelocalized craters, pits, fluting orcorrugations. Electric burns mayo c c u r a t s e v e r a l p l a c e ssimultaneously or any or all of thebearings of the vehicle. Affectedbearing parts must be rejected.

It is important that at the time ofwelding, ground cable must beattached in such a way that currentwill not flow through the bearing.

NICKSNicks are surface damages causeddue to rough handling of bearingparts. Parts must be stone smooth if repairable and does not affect the proper functioning of the part.

CRACKS & FRACTURE A crack of any size /length is found on any roller, cage or cup, the comonent should be scrapped.

Fig. 32

Fig. 33

47


SERVICE & MAINTENANCE FACILITIES, OFFERED BY N.E.I.The maintenance of cartridge bearings requires sophisticatedtechnical competence and has to be done by establishedmanufacturers, of cartridge bearings,only. Normally suchestablishments have to obtain A.A.R. approval and aresubjected to periodic inspection. N.E.I. has imported completemaintenance and re-manufacturing line from its collaboratorM/s. BRENCO. This facility has been inspected and approvedby BRENCO, the Railway Board and the RDSO.

N.E.I. Engineers have received extensive training in servicingand maintaining the cartridge bearings at BRENCO. Speciallytrained mounting teams to handle cartidge bearings havebeen stationed at different locations all over India, to offer thebest services at all times. backed by trained Service Engineers.

HANDLING OF MOUNTED WHEEL SETS, DURING TRANSIT1. It is very important that the wheel sets are handled carefully dur ing t ransportat ion before and af ter mount ing the cartridge bearings. RDSO has designed suitable lifting tackles for loading and unloading of the wheels sets, from the ships and the railway wagons and yards.

2. RDSO has also issued a drawing of the loading arrangement of the axles in the wagons. The above instructions must followed at all stages of transhipment.

48

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