NBC Training Report

Arya Institute of Engg. Technology & management Page 1
Study of Remanufacturingof Cartridge Tapered Roller
Bearing (CTRB) 6X11
A
Project Report
Submitted
In partial fulfilment
For the award of the Degree of
Bachelorof Technology
In Department of Mechanical Engineering
Supervisor: Submitted By:
Mr. Praveen Mishra Ravindra Kumar Punia
Manager Enrolment no.:13EAOME045
Railway Bearing Assembly
Department of Mechanical Engineering
Arya Institute of Engg. Technology & management
Rajasthan technical university
23 May,2016-22 July, 2016

Candidate’s Declaration
I hereby declare that the work, which is being presented in
the Dissertation, entitled
A Project Report on Study of Remanufacturing of Cartridge
Tapered Roller Bearing (CTRB) 6X11 in partial fulfilment for
the award of Degree of “Bachelor of Technology” in
department Of Mechanical Engineering with Specialization in
and submitted to Arya Institute of Engg. Technology &
management, Rajasthan Technical University is a record of
my own Investigations carried under the Guidance of Shri/
Mr. ........................................., Department of mechanical
Engineering, arya Institute of Engg. Tech. & management
I have not submitted the matter presented in this report
anywhere for the award of any other Degree.
(Name and Signature of Candidate)
Enrolment No.: 13EAOME045
Arya Institute of Engg. Tech. & management
Counter Signed by
Name(s) of Supervisor(s)
.....................................
.....................................

CONTENTS: Page No.
Chapter1: Company Profile 5
Chapter 2: Introductionof bearing
2.1: Types of bearing 12
Chapter3: Manufacturingof ball Bearing
3.1: Raw material 18
3.2: Manufacturing Process 18
Chapter4: Manufacturingof Taper Roller Bearing
4.1: Raw Material 26
4.2: Cup and Cone 26
4.3: Cage’s 27
4.4: Heattreatmentprocess 27
4.5: Different process for cone 28
4.6: Different processforcup 31
Chapter5:Project
5.1: Objective 35
5.2: Cartridge Tapered Roller bearing (CTRB) 35
5.3: Nomenclature & Description of bearing parts 36
5.4: Maintenanceand Repair of CTRB 38
5.5: Inspection of Bearing Components 39
5.6: Defects of Bearing Units 42
5.7: Grinding Operation 43
5.8: C (Phosphate Coating) – Shop 44

5.9: Process Flow in Assembly Line 46
Reference 48

CHAPTER 1
COMPANY PROFILE:
National Engineering Industries ltd. manufactures a wide
range of bearings for automotive and railway industry as well
as or general industrial application under the brand name
NBC. NEI, founded in the year 1946 as a pioneer industry in
the field of bearing manufacture, now manufactures nearly
80 Million Bearings per annum in over 500 different sizes
ranging from 6 mm bore to 1300 mm outer diameter having
capability to manufacture bearing up to 2000 mm. diameter.
NEI manufactures a wide range of bearings namely ball and
cylindrical roller bearings, double row angular contact
bearings, tapered roller bearings for automobiles, railways
and industrial applications and large diameter bearings for
steel plants and rolling mills. The three plants situated at
Jaipur, Newai and Manesar manufacture these products with
approx. 2300-strong team, supported by a well-equipped
R&D with bearing life testing facility.
PLANT AT JAIPUR:
(i). Ball Bearing:
Precision Ball Bearings from 6 mm bore to 75 mm bore
diameter are manufactured on state of the art manufacturing

facilities with in-process and post-process gauging in grinding
and centrally air conditioned assembly lines with auto
gauging and testing equipments. The latest advanced
techniques for manufacturing and Quality Assurance are
implemented to meet the rapid increase in demand for
Quality, diversity of specifications and new types of bearings.
This Divisionis spread over a covered area of 14,694 Sq.
Meters.
ii). Steel Ball:
Precision Steel Balls up to 25 mm diameters for NBC Bearings
are manufactured on precision grinding and lapping
machines to achieve super finished surface, accuracy and
roundness as per ISO standards.
This Division is spread over a covered area of 4,700 Sq.
Meters.
(iii). Tapered Roller Bearing:
Precision Tapered Roller Bearings are manufactured in Inch
and Metric series from 15.875mm bore to 95.25mm bore
with technology obtained from our earlier collaborator,

Federal Mogul Corporation, USA and now with NTN
Corporation, Japan. These bearings are used by all major
Automobile manufacturers in the country as Original
Equipment.
This Divisionis spread over a covered area of 11,652 Sq.
Meters.
(IV). Railway Bearing:
Roller Bearing in Axle Box: With the production of Roller
Bearings and Axle Boxes since 1952, the company has fully
met the requirements of the Indian Railways (one of the
largest systems of the world) by designing and developing
Axle Boxes and bearings for fitment to Locomotives
manufactured by Diesel Locomotive Works, Chittaranjan
Locomotive Works, various wagon builders, the ICF broad
and meter gauge coaches. Over a millionNBC bearings and
boxes are in service with the Indian Railways. The
development of completely indigenized Axle Boxes and
bearings for the high speed Rajdhani Locomotive, the
Yugoslavian and Egyptian Railway wagons are the
highlights of the design capabilities at NEI. On date more

than 100 types of Axle Boxes & Bearings have been
manufactured.
Spherical Roller Bearing: The manufacturing of Spherical
Roller Bearings was started in the year 1975-76 for fitment
to broad gauge and meter gauge passenger coaches with
designs, technology, machines and equipment procured
from the collaborators.
Cartridge Tapered Roller Bearing: For fitment to the new
BOX-IN Up rated Wagons designed by the RDSO, NEI is the
only manufacturer in the country to indigenize these
bearings to a high percentage under collaboration with the
largest manufacturer of these bearings in the world.
Production of these bearings commenced in the year1984.
These bearings are grease packed and require no field
lubrication for a period of 7 years.
This Division is spread over a covered area of 4,855 Sq. M.
(v). Large Diameter Bearing:
Self-sufficiency in steel is the call of the day, so is the
importance of bearings in Steel Mills Equipment. NEI has the
distinction of being one of the ten manufacturers of these

bearings in the world, who can manufacture large diameter
bearings up to 2000 mm diameter.
The largest bearing manufactured by NEI for fitment to the
Plate Mill of Rourkela Steel Plant was released by Mr. G.P.
Birla in September 1985. This 4-Row Tapered Roller Bearing
measures 1300 mm diameter and weigh 4.39 tons.
The large diameter bearings are mainly manufactured out of
case carburizing steel, heat treated on special equipment and
furnaces developedby NEI. Precision grinding is done to close
tolerances on CNC Twin Spindle Programmable Berthiez
Machine for bearings ranging from 500 to 2000 mm diameter
with electronic sizing and numerical display.
Production of these bearings started in 1975 and to date over
100 different types of special large diameter bearings have
been manufactured and successfully used, saving
considerable foreign exchange for the country.
The Large Diameter Bearings Division is spread over a
covered area of 2,508 Sq. Meters.
RESEARCH & DEVELOPMENT AT JAIPUR :
Design & Development: Complete in-house facility for design
development of all types of bearings and tooling is available.

The design of all types of bearings is done on Pro-Engineer
3D Modeling & Analysis Software.
Complete engineering and research facility is available to
solve intricate problems with expert advice on design,
development, manufacturing, installation and maintenance
of bearings. With the signing of the technical collaboration
agreement with NTN Corporation, Japan & BRENCO Inc of
USA, the capability to offer finest engineering services in the
bearing industry has enhanced. Services of team of
experienced engineers are available for selection of bearing
as per application.
Machine Building :NEI has the capability of machine building
to design, develop and manufacture special purpose CNC
Grinding Lines, HT Lines, Material Handling Equipments and
other special purpose machines which have been made for
its captive use to keep pace with latest technology.
A well equipped electronic design, development laboratory
with all testing facilities supports the Machine Building
Division.

CHAPTER 2
INTRODUCTION OF BEARING
A bearing is a machine element that constrains relative
motion to only the desired motion, and reduces friction
between moving parts. The design of the bearing may, for
example, provide for free linear movement of the moving
part or for free rotation around a fixed axis; or, it
may prevent a motion by controlling the vectors of normal
forces that bear on the moving parts. Many bearings
also facilitate the desired motion as much as possible, such
as by minimizing friction. Bearings are classified broadly
according to the type of operation, the motions allowed, or
to the directions of the loads (forces) applied to the parts.
2.1TYPES OF BEARINGS
Ball Bearings:
Ball bearings are the most common and most used type of
bearing found in a number of objects. Also known as anti-

friction bearings, ball bearings are
small metallic or ceramic spheres
used to reduce friction between
axles and shafts in numerous
applications. These bearings are
able to handle both thrust and
radial loads, and are used for
applications where the load is relatively small. Load in a ball
bearing is transmitted from the outer surface to the ball, and
from the ball to the inner surface. Since the ballis spherical in
shape, it contacts the inner and outer race at a very small
point, which helps it spin evenly and smoothly. But the
contact area holding that load is very small, so if the bearing
is overloaded then the balls can deform, ruining the bearing.
Ball bearings are often used in individual cages to reduce
friction in axle assemblies or in a series to absorb the weight
placed on a moving part.
Roller Bearings:
Roller bearings use cylinders instead of
spheres that means the contact between the
inner and outer race is a line not a point.
Thus the load is spread over a larger area
enabling the bearing to handle greater loads
than ball bearings. Roller bearings are used in conveyer belt
rollers where they hold heavy radial loads, however these

bearings are not designed to handle much thrust loading.
Roller bearings are found in different varieties, such as
spherical roller bearings, needle roller bearings, cylindrical
roller bearing, thrust roller bearing, tapered roller bearing,
etc.
Needle Roller Bearing:
Needle roller bearings are special roller
bearings having slender cylindrical rollers
that enable them to bear highest load
capacity for a given radial space of all rolling-
element bearings. Needle roller bearings are ideal for
applications where high radial load carrying capacity is
required but radial space is limited. Such bearings also suit
applications where high rotational speed is involved but
cannot accommodate axial loads.
Compared to the ball bearings, needle bearing have a large
surface area that is in contact with the bearing outer
surfaces. Additionally they are more compact because there
is less difference between the diameter of the shaft and the
diameter of the bearing.
Thrust needle bearings are flat and use a radial pattern of
needles while radial needle bearings are cylindrical and use
rollers parallel to the axis of the shaft.
Needle bearings are primarily used in engine componentslike
pumps, compressors, rocker arm pivots, and transmissions.

Tapered Roller Bearing:
Tapered roller bearings use conical rollers
that run on conical races. Both the inner and
outer raceways are segments of cones and
the rollers are also made with a taper. Unlike
other roller bearings, they support both
radial and axial loads, and are able to carry
higher loads. The conical geometry of tapered roller bearings
provide a larger contact patch, which allows greater loads to
be carried as compared to spherical (ball) bearings. The
geometry ensures that the tangential speeds of the surfaces
of each of the rollers are same as their raceways along the
whole length of the contact patch and no differential
scrubbing occurs. This greatly reduces rolling friction and
avoids rapid wear. Taper roller bearings are used in the
wheel bearings of most trucks, buses, cars, and so on. Due to
manufacturing complexities, tapered roller bearings are
generally more expensive than ball bearings.
Spherical Roller Bearings:
Rollers used in spherical roller bearings are
thicker in the middle and narrow at the
ends, and its race is shaped to match. They
can adjust to support misaligned loads.
The constructions of spherical rollers are complex and
difficult to produce so they are expensive. Apart from that
these bearings have higher friction compared to ball bearing

because different parts of the spherical rollers run at
different speeds on the rounded race. Thus there are
opposing forces along the bearing/race contact increasing
the friction. Spherical bearings are used in numerous
applications where rotational motion changes the alignment
of its axis of rotation. One of its important example is a tie
rod on a vehicle suspension. Other important uses of
spherical bearings have been in car suspensions, trackballs,
computer mouse, heavy machinery, sewing machines, drive
shafts, etc.
Thrust Bearings:
Thrust bearings are particular types of rotary bearing that
allow rotation between parts used but they are designed to
support axial loads like vertical shafts for which spherical,
conical or cylindrical rollers are used. They are used in gear
sets like in car transmissions between gears
and between the housing and the rotating
shafts.
Thrust bearings are of different varieties.
Ball thrust bearings are composed of ball
bearings supported in a ring. They are used in low thrust
applications where the radial load is very small. Thrust roller
bearings are made of small tapered rollers arranged so that
their axes converge at a point on the axis of the bearing.

CHAPTER 3
MANUFACTURINGOF BALL BEARING
3.1 Raw Materials
Almost all parts of all ball bearings are made of steel. Since
the bearing has to stand up to a lot of stress, it needs to be
made of very strong steel. The standard industry
classification for the steel in these bearings is 52100, which
means that it has one percent chromium and one percent
carbon (called alloys when added to the basic steel). This
steel can be made very hard and tough by heat treating.
Where rusting might be a problem, bearings are made from
440C stainless steel.
The cage for the ballsis traditionally madeof thin steel, but
some bearingsnow use molded plastic cages, because they
cost less to make and cause less friction.
3.2The Manufacturing Process
There are four major parts to a standard ball bearing: the
outer race, the rolling balls, the inner race, and the cage.
Races
1. Both races are made in almost the same way. Since
they are both rings of steel, the process starts with steel
tubing of an appropriate size. Automatic machines
similar to lathes use cutting tools to cut the basic shape
of the race, leaving all of the dimensions slightly too
large. The reason for leaving them too large is that the

races must be heat treated before being finished, and
the steel
Surprisingly, the rolling balls start out as thick steel wire. Then, in a cold
heading process, the wire is cut into small pieces smashed between two
steel dies. The result is a ball that looks like the planet Saturn, with a ring
around its middle called "flash."
Usually warps during this process. They can be
machined back to their finished size after heat treating.
2. The rough cut races are put into a heat treating
furnace at about 1,550 degrees Fahrenheit (843 degrees
Celsius) for up to several hours (depending on the size of
the parts), then dipped into an oil bath to cool them and
make them very hard. This hardening also makes them
brittle, so the next step is to temper them. This is done
by heating them in a second oven to about 300 degrees
Fahrenheit (148.8 degrees Celsius), and then letting
them cool in air. This whole heat treatment process
makes parts which are both hard and tough.
3. After the heat treatment process, the races are ready
for finishing. However, the races are now too hard to cut

with cutting tools, so the rest of the work must be done
with grinding wheels. These are a lot like what you
would find in any shop for sharpening drill bits and
tools, except that several different kinds and shapes are
needed to finish the races. Almost every place on the
race is finished by grinding, which leaves a very smooth,
accurate surface. The surfaces where the bearing fits
into the machine must be very round, and the sides
must be flat. The surface that the balls roll on is ground
first, and then lapped. This means that very
fine abrasive slurry is used to polish the races for several
hours to get almost a mirror finish. At this point, the
races are finished, and ready to be put together with the
balls.
Balls
4. The balls are a little more difficult to make, even
though their shape is very simple. Surprisingly, the balls
start out as thick wire. This wire is fed from a roll into a
machine that cuts off a short piece, and then smashes
both ends in toward the middle. This process is called
cold heading. Its name comes from the fact that the
wire is not

The bulge around the middle of the rolling balls is removed in a machining
process. The balls are placed in rough grooves between two cast iron discs.
One disc rotates while the other one is stationary; the friction removes the
flash. From here, the balls are heat treated, ground, and lapped, which leaves
the balls with a very smooth finish.
Heated before being smashed, and that the original use for
the process was to put the heads on nails (which is still how
that is done). At any rate, the balls now look like the planet
Saturn, with a ring around the middle called "flash."
5. The first machining process removes this flash. The ball
bearings are put between the faces of two cast iron disks,
where they ride in grooves. The inside of the grooves are
rough, which tears the flash off of the balls. One wheel
rotates, while the other one stays still. The stationary wheel
has holes through it so that the balls can be fed into and
taken out of the grooves. A special conveyor feeds balls into
one hole, the balls rattle around the groove, and then come
out the other hole. They are then fed back into the conveyor
for many trips through the wheel grooves, until they have
been cut down to being fairly round, almost to the proper
size, and the flash is completely gone. Once again, the balls
are left oversize so that they can be ground to their finished
size after heat treatment. The amount of steel left for
finishing is not much; only about 8/1000 of an inch (.02
centimetre), which is about as thick as two sheets of paper.
6. The heat treatment process for the balls is similar to that
used for the races, since the kind of steel is the same, and it
is best to have all the parts wear at about the same rate.
Like the races, the balls become hard and tough after heat
treating and tempering. After heat treatment, the balls are

put back into a machine that works the same way as the
flash remover, except that the wheels are grinding
wheels instead of cutting wheels. These wheels grind the
balls down so that they are round and within a few ten
thousandths of an inch of their finished size.
7. After this, the balls are moved to a lapping machine,
which has cast iron wheels and uses the same abrasive
lapping compound as is used on the races. Here, they will be
lapped for 8-10 hours, depending on
The four parts of a finished ball bearing: inner race, outer race, cage, and
ball.
Cage
8. Steel cages are stamped out of fairly thin sheet metal,
much like a cookie cutter, and then bent to their final
shape in a die. A die is made up of two pieces of steel
that fit together, with a hole the shape of the finished

part carved inside. When the cage is put in between and
the die is closed, the cage is bent to the shape of the
hole inside. The die is then opened, and the finished
part is taken out, ready to be assembled.
9. Plastic cages are usually made by a process called
injection moulding. In this process, a hollow metal
mould is filled by squirting melted plastic into it, and
letting it harden. The mould is opened up, and the
finished cage is taken out, ready for assembly.
Assembly
10. Now that all of the parts are made, the bearing
needs to be put together. First, the inner race is put
inside the outer race, only off to one side as far as
possible. This makes a space between them on the
opposite side large enough to insert balls between
them. The required number of balls is put in, then the
races are moved so that they are both cantered, and the
balls distributed evenly around the bearing. At this
point, the cage is installed to hold the balls apart from
each other. Plastic cages are usually just snapped in,
while steel cages usually have to be put in and riveted
together. Now that the bearing is assembled, it is coated
with a rust preventative and packaged for shipping.
Quality Control
Bearing making is a very precise business. Tests are run on
samples of the steel coming to the factory to make sure that
it has the right amounts of the alloy metals in it. Hardness
and toughness tests are also done at several stages of the

heat treating process. There are also many inspections along
the way to make sure that sizes and shapes are correct. The
surface of the balls and where they roll on the races must be
exceptionally smooth. The balls can't be out of round more
than 25 millionths of an inch, even for an inexpensive
bearing. High-speed or precision bearings are allowed only
five-millionths of an inch.

CHAPTER 4
MANUFACTURING OF TAPER ROLLER BEARING
Forged ring (De-scaled) as raw material
Turning Operation
Centre less grinding
Heat Treatment
Hardness Testing
Rough Grinding
Finish Grinding
Honing & super finishing
Washing
Application for Rust preventive
Ready for dispatch to assembly

Tapered roller bearings and have the following components:
outer ring, inner ring, and roller assembly (containing the
rollers and a cage). The non-separable inner ring and roller
assembly is called the cone, and the outer ring is called
the cup. Internal clearance is established during mounting by
the axial position of the cone relative to the cup.
4.1 RAWMATERIAL:
The Races& Rolling elementsofBearingaresubjectedtostressona
very small contact surface must be of such material also asto with
stand wear and have high elastic Limit & fatigue Limit. The raw
material being used by the Industry forManufacturing of various
Bearingcomponentsareasunder:
4.2 CUP AND CONE:
The raw material used in the Manufacturing ofbearingRacesisSAE
52100 high Carbon Chrome bearing steel, which has composition
similarto EN-31 (100 CR 6 AsperBIS specification).Therawmaterial
for Bearing Races is in the form of Rods &Seamless Hollow Tubes.
This is a Spheroids Annealed Steel. Approx. 80% of the Seamless
Hollow tubes are purchased by the Industry from M/s. Indian
Seamless Metal tube PUNE.The Steel bar are purchased from M/s.
Indian Seamless Steel & Alloy Pune & M/s. Mahindra Ugine Steel
Company KHAPOLI (Maharashtra).Some of the unitsare buying the
steel scrap rod for manufacturing bearing races. Bearing Races
material and their heat treatment are required to be selected
carefully, taking account the mechanical strength and required life
of the Bearing, Approximate required composition for bearing
races are Constitute % Composition Carbon0.95 to1.1
Chromium1.4to1.6Manganese0.50max.Silicon0.15to0.35Sulphu
r 0.025 (Max.)Phosphorous0.05.

4.3 CAGE'S:
Cage isused to returnballsatproperdistancetopreventthemfrom
containing eachother and to prevent a temperature rise and
resultantdamageduetofriction.
The Material for manufacturing cages is CRCA Strips of C2015
Bearing grade steel having carbon percentage at0.08% max. and
Magnesiumrangingfrom0.25% to0.45%
4.4 HEATTREATMENTPROCESS:-
Heat treatment process is the process of hardening the soft
material. The rawmaterialissoftmaterialandithastobehardened
before grinding, and hardening increase the life of bearing.
Hardening isdone in a special furnace named CHUGAIRO furnace.
Thesoft machinedmaterialisfeedinthefurnaceandwashedat600
C, then send to a chamber where the material heated in four
chambers the first chamberhasthe temperature 8400
C and further
chambercontainsthe 8500
Ctemperature.Thenitdippedintoanoil
tank at temperature 250
C where the material get quenched then it
washed and then it tempered in water about 90 min. at
temperature 1050
C .then dried and cooled in air. The hardened
material isobtained. The systematic flowchartisshowninfollowing
fig:

Afterheattreatmentfollowingprocessaredone:
4.5 DIFFERENT PROCESS FOR CONE:-
DimensionsChecking
Before starting the grinding process, various dimensions of cone
shouldbecheckedin amachineormanually.Variousdimensionsto
be checked are: Flange diameterCone width Cone track
diameterBorediameter.
FaceGrinding
Face isthesurfaceatsideoftheinnerandouterrace,faceshouldbe
finished indeed to get the desire width of the bearing and sincethe
bearing is a mating part and it has to be assembled somewhere in
the machine where it should be fit precisely. The face grinding is
done in a machine where the faces are grinded in between the
grindingwheel.
SizeLimit: UCL+35 µm: LCL -35 µm

WidthVariation:5µm
There are varioussemi-automaticfacegrindingmachineinstalledin
tapersectionforcone
1. DAISHOMACHINE
2. NISSEIMACHINE
3. NISSEIMACHINE
OD (Outer Dia.)Grinding
OD is the circumferential surface of the outer race of the bearing.
The OD should be surface finished since the bearing has to be
assembledinmachine.Itisobtaininan ODgrindingmachine.Inthis
machine the outerrace isrotatedbetweentwogrindingwheel.The
outerrace ispassed in machine three timesto gethighlyfinishedas
follows:
1. Rough1
2. Rough2
3. Finefinish
SizeLimit: 15to35 µm
TargetSize:+30 µm
Flange Grinding
The flange should be surface finished since the bearing has to be
assembled in machine. Itisobtainintheflangegrindingmachine.In
this machine one grinding stone isused to cut and grind the flange
portionofcone.
NCMode-AUTO
FeedMode-AUTO
Override-120% (usedtochangemachinespeed.)

Toolmovementduringgrindingisinallthreedimensionalaxesi.e.X,
Y,Z axis.
BoreGrinding
Bore is the inner circumferential surface of the bearing. The bore
should be surface finished since the bearing hasto be assembledin
machine. It is obtain in the bore grinding machine. In thismachine
thegrindingstoneismovedinXandYaxis.
SizeLimit: +4µm to-4 µm.
TOOL movement duringgrindingisinonlytwodimensionalaxesi.e.
X, Z axis.
AutoDimensionCheck
Various dimensions of cone are checked in this machine. This
machineincludesvarioussensorsforsensingthedimensionofcone.
Thismachineuseweightsensors andpositionsensorstoidentifythe
position and weight of cone. All dimensions should be checked in
thismachine.
M1 Φ0.7 ID1 -X
M2 Φ2.1 ID2 - X
M3 Φ-2 TAPER
M4 Φ-0.2 ID1- Y
M5 Φ1.6 ID 2–Y
M6 Φ0.9 OVALITY
It automatically discards the work piece if its dimensions are not
compatiblewithpre-feeddata.Thelimitationsofsizeare:
Sizelimit:+4 µmto 4µm.
TAPER: 5µm maximum
OOR:5µm maximum
CHATTER:3µm maximum
SQUARENESS:5 µm maximum

HoningMachine
Honingisanabrasivemachiningprocessthatproducesaprecisionsu
rfaceona metalworkpiecebyscrubbinganabrasivestoneagainstit
along a controlled path. Honing is primarily used to improve the
geometric form of a surface, but may also improve the surface
texture.
4.6 DIFFERENTPROCESSFORCUP:
OD Grinding
OD is the circumferential surface of the outer race of the bearing.
The OD should be surface finished since the bearing has to be
assembledinmachine.Itisobtaininan ODgrindingmachine.Inthis
machine the outerrace isrotatedbetweentwogrindingwheel.The
outerrace ispassed in machine three timesto gethighlyfinishedas
follows:Rough1,Rough2,Finefinish.
Size Limit:15 to35 µm
TargetSize: +30 µm
HoningMachine
Honingisanabrasivemachiningprocessthatproducesaprecisionsu
rfaceona metalworkpiecebyscrubbinganabrasivestoneagainstit
along a controlled path. Honing is primarily used to improve the
geometric form of a surface, but may also improve the surface
texture.
ASSEMBLYLINE:
OncerespectiveCUPandCONEofcorrespondingbearingisfinished,
they are sent in the Assembly line where these cup and cone get

assembled with retainers having rollers in them and after some
importanttest,theyarefinallypackedandarereadyforuse.
LaserPrintingMachine:
It is a machine which is used for marking purpose of the company
brand and specification on respective cup orcone. Thistechnology
utilizes laser beam formarking. The movement of laser beam is
controlled by automatic 3d table movement. The point on metal
surfaces where these laser beams hits leave marks as required.
Names of few Laser Machine which are installed in Taper Bearing
Sectionare:
1. AKSHARFIBER-PRO
2. SAJIAJANANDLaserTechnologyltd
RollFillingMachine:
It is an automatic machine which is actuated by pneumatic
technology. In this machine, first Retainer is placed on first station
where rollersare inserted attheirrespectiveposition.Thentheyare
sensed by position sensor, actuated by pneumatic and then coneis
fixedwithincage.
PressingMachine:
It is an automatic machine which is actuated by pneumatic and
hydraulic technology both. The Cone is pressed against Retainer
with down stroke powered by hydraulicsand upstroke poweredby
pneumatics.
Weight check:
At this station, Weight of bearing is checked and if the weight
is not compatible with the given standard of weight limits,
machinewillrejecttheworkpiecesample.

Demagnetizer:
It is a machine which isused to remove magnetism induced during
theaboveprocess.It isdonebyimpacthitting.
Washing:
Thenthebearingiswashedbyfaststreamofkerosene jet.
Noisechecking:
The bearing is supposed to be produce low noise hence this
machine rotates the bearing at certain rpm and noise is checked.
Thenoiselimitisnearby0.1Mpa.
Presschecking:
At this station, the bearing is checked whether its assembly
is pressed properly or not.
Finalchecking:
This machine has 2 or 4 stations where various dimensionsof final
bearing are checked. If any bearing is found incompatible with the
given dimensionsand tolerances, they arerejectedbythemachine.
In ideal position 1, width of bearing, run out and comets or
clearance of bearing is checked. And at ideal position 2, bore size,
taperandroundnessarechecked.
All those bearingswhich does not have compatiblesize and tol
erance with the given data, they are rejected by the machine
itselfIdealposition.
1:width,runout,cometIdealposition
2:boresize, boretaper,boreroundness
OilingandDrawerMachine:

In this machine, bearing is subjected to a fast flowing stream of
coolant which is used to lubricate the bearing parts. And then the
excess oilisagainsuckedbythemachine.
VisualInspection:
Now, the bearing is checked manually by the operators. All the
dimensions and surface properties are checked and rejected work
piecearesentagainforcorrection.
Packing:
Finally,finishedproductispackedformarketuseandexport.

CHAPTER 5
PROJECT
5.1OBJECTIVE: Study of remanufacturing of Cartridge
Tapered Roller Bearing (CTRB) 6X11.
5.2CARTRIDGE TAPERED ROLLER BEARING (CTRB):
For fitment to the new BOX-IN Updated Wagons designed by
the RDSO. NEI is the only manufacturer in the country to
indigenise these bearings to a high percentage in
collaboration withthe largest manufacturer of these bearings
in the world. Production of these bearings commenced in the
year 1984. These bearings are grease packed and require no
field lubrication for a period of 7 years.
The BRENCO-NBC CTRB is a self-contined,pre-assembled,pre-
adjusted,pre-lubricated,completelysealed unit and is applied
to or removal from the axle without exposing the bearing
elements seals or lubricants to contamination or damage.
5.3NOMENCLATURE AND DESCRIPTION OF BEARING PARTS:

1. Cone Assembly
The cone, rollers and cage assembly is perfectly matched to
ensure long service life. Assembly configurations are similar
to standard single row tapered roller bearing. Both cone and
rollers are manufactured from bearing quality case hardened
steel.
2. Cup
The double cup is forged, rolled and machined from bearing
quality case hardened steel. The cup has two tapered
raceways. It also has seal grooves located at each end,
precision machined to affect a leak -proof fit to provide
positive locking for the grease seals.
3. Spacer
The spacer width is precision ground and selected at the
factory to achieve proper axial clearance in an assembled
bearing. Subsequent adjustment or interchange at the time
of installation should not be done.
4. Wear ring
The wear ring is a steel ring, heat treated& precision ground
on the OD to provide a smooth, concentric mating surface for
the grease seal. The bore diameter of the wear ring has an
interference fit with axle.

5. Grease seal
The seal is made of special synthetic rubber of superior oil
resistance quality bonded with metal casing by a special
process. The primary function of the roller bearing seal is to
keep vital lubricating grease inside the bearing.
The BRENCO-NBC Cartridge Roller Bearing are fitted with the
DDL(double Dust Lip) grease seals which are best seals,
proven for excellent performance& also helps in reducing
fuel consumption and cooler running of bearing.
6. End cap
The end cap is affixed to the axle by three cap screws and is
designed for sufficient rigidity to maintain proper cap screw
tension, even after years of service. The wear ring should
seat properly inside the recess of end cap to prevent ingress
of water.
7. Axle Cap Screws
The axle cap screws affix the axle end cap with axle to
provide sufficient clamping of the bearing on the journal.
Both used & new cap screws should be lubricated with oil
before installation.
8. Locking Plate
The locking plate provides tabs which are bent against the
flats of the cap screws after tightening, thus preventing their

undesired turning and subsequent loss of bearing lateral
clamp.
9. Backing ring
The backing ring positions the bearing, provides a firm base
and helps prevent intrusion of dirt, water and other foreign
substances.
5.4MAINTENANCE AND REPAIR OF CARTRIDGE TAPERED
ROLLER BEARING:
Bearing Disassembly
For disassembly of the CTRB steps to be followed are listed
below:
1. Remove backing ring, wear rings and excess grease and
excess grease from 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 taken to prevent unnecessary damage to the
bearing while removing seals. Used grease seals must be
scrapped
3. Remove both cone-assemblies and spacer from the cup.
4. All parts disassembled from the 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
accomplished 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 rings 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.
5.5INSPECTION OF BEARING COMPONENTS
After this cleaning take palace bearing parts to the inspection
area. The inspection area must be well lighted and clean. Use
bearing manufacturer's specifications for sizes and wear
limits for all bearing assembly component parts during
inspection.
End cap
Inspect the end cap for surface damage, cracks, breakage,
wear or distortion. Any other condition that would affect
proper seating of the end cap on wear ring face must be
corrected if possible otherwise defective end cap is to be
rejected.
Backing Ring

1. Check the backing ring visually for crack, distortion,
excessive corrosion, wear and heavy pitting and scrap
backing rings having such defects.
2. Ensure that counter bore of the backing ring must provide
a press fit on wear ring.
3. Breakout diameter of the backing ring shall not exceed the
specified limits.
4. Backing ring with vent holes must not be allowed for
further services.
Cap screws
Cap screw thread for damage and wear, cap screw body for
elongation are checked. Cap screws having burrs extending
beyond washer face on the under side
Of cap screw head as this will damage the locking plate. Cap
screws must be lubricated before reapplication.
Grease seals
Used grease seals must be scrapped and must be replaced
with new grease seals only.
Spacer
Spacers are visually examined for cracks, nicks.
Cracked spacer must be scrapped.
Cone Assembly
Inspect the raceways visually for staining, acid etching,
corrosion, spailing. Cone assembly should always be checked
for indentations, electric burns, crack etc.

Use suitable well lit stand for the inspection of the cone
assembly and turn cage and rollers while examination of
cone assembly.
Cup
All cups should be checked for wear patterns seen on the cup
outside diameter not only because of its importance on the
life of the bearing but also as it reveals excessive wear of the
adapter.
In case of fully worn-out adapter the cup starts contacting
the adapter at the ends also. Worn out adapters must be
scrapped. Displaced adapters also form two distinguished
marks on the cup outside diameters.
Visually examine cup raceways for staining, acid etching,
corrosion, pitting, heat discoloration false brinelling and
spalling, electric burns, crack etc.
After the visual inspection, the defective piece which cannot
be used again are thrown away while the other piece are
again send for heat treatment, grinding and further
operations.

5.6DEFECTS OF BEARING UNITS
5.7GRINDING OPERATION:
Following are the process flow for grinding carried out in NBC
for CTRB parts:

Process flow for cup:
1. O.D Grinding:
O.D Grinding means grinding of outer diameter surface of
cup. In this there is a grinding wheel and a regulating wheel.
In this there are 3passes for a new job in which it is turned
from black to finish while 2 passes for used one.
2. Face Grinding:
It is a double disc grinder having reciprocating shuffle for
better accuracy. It also has Digital Read out (DRO) for size
adjustment.
3. Bore Grinding:
In this there is simultaneous track & Counter bore grinding.
Process flow for cone:
1. Face Grinding:
It is done though a double disc grinder featured with auto
dressing and auto load unload by gantry.
2. Track, Flange, Rib OD Grinding:
In this process there is simultaneously track, flange & rib OD
grinding. Dressing is done by interpolation of roll dressers. In
this there is only a single pass through which black to finish
grinding is done.
3. Bore Grinding:

In it dressing is done by roll dressers. In this process cup
surface is grinded from black surface to finish surface in
single pass.
Process flow for rollers:
1. Outer Diameter Rough Grinding
2. End face Grinding
3. Outer Diameter finish Grinding
4. Outer diameter crowning
5. Outer diameter super-finishing
After this inspection of rollers is done, then they are fitted
into cage.
5.8 C(Phosphate Coating) – SHOP
Objectives - Phosphate coating are used on steel part for
1) Corrosion resistance,
2) Lubricity,
3) Foundation for subsequent coating or painting
Cup and cone are forwarded for phosphating.
PROCESS – The application of phosphate coating makes use
of phosphoric acid and takes advantage of the low solubility
of phosphates in medium or high pH solutions. Iron, zinc or
Mg-phosphate salts are dissolved in a solution of phosphoric

acid. When steel or iron parts are placed in phosphoric acid, a
classic acid and metal reaction takes place which locally
depletes the hydronium ions, raising the pH, and causing the
dissolved salt to fall out of solution and participated on
surface. The acid and metal reaction also creates iron
phosphate locally which may also deposit. In the case of
depositing zinc phosphate or Mg-phosphate the additional
iron phosphate is frequently an undesirable addition to the
coating.
The acid and metal reaction also generates hydrogen gas in
the form of tiny bubbles that adhere of the metal. These
prevent the acid from the reaching the metal surface and
slows down the reaction. To overcome this sodium nitrite is
frequently added to act as an oxidizing agent that reacts with
the hydrogen to form water. This chemistry is known as a
nitrate solution. Hydrogen is prevented from forming a
precipitating layer on the surface by the oxidant additive.
Powder Coating: Steps in powder coating

After Phosphating, cone is forwarded for assembly.
Phosphated cone are assembled with cage having rollers and
are pressed so that the rollers don't come out and then they
are lubricated and sent to assembly line.
5.9 Process Flow In Assembly Line:
1. Firstly a cone assembly is put into a cone with an axle
alignment
2. Spacer is put between the two cone assembly in a cup and
then the assembly is proceeded for laser marking.
3. Grease seals are put on the cup.
4. Then end cap and back rings are put on the assembled
bearing and then preceded for packing.
Packing
Special attention has been given to protective packing.
Bearing assembly is wrapped in polythene sheet and grease-
proof brown Paper. A cardboard packing tube (triangular) is also
inserted inside the bearing to keep the spacer aligned with the
cone assembly.
Each bearing assembly is packed in a corrugated box and each
wooden box contains two cartons of bearing assemblies.
The Axle end cap & Locking plate, axlecapscrews,side framekey,bolt &
nut with spring washer & adapter are packed in separate
corrugated boxes, each wooden box contains parts for four bearing
assembly.

Reference:
1.https://en.wikipedia.org/wiki
2.www.rdso.indianrailways.gov.in
3.https://en.wikipedia.org/wiki/Bearing(mecha
nical)

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