Nbc Training Report - ball bearing division

Industrial Training Report

A

Practical Training Report

On

“BALL BEARING DIVISION”

Submitted

in partial fulfillment

for the award of the Degree of

Bachelor of Technology

In

Mechanical Engineering

Submitted To: Submitted By:

Mr. Sandeep Jhamb SANJAY

Head of Department Roll No.11EAIME053

Department of Computer Science &Engineering

Arya Institute of Engineering & Technology, Jaipur

Mechanical Engg. Deptt. A.I.E.T., Jaipur


A

Practical Training Report

On

“BALL BEARING DIVISION”

Submitted

in partial fulfillment

for the award of the Degree of

Bachelor of Technology

In

Mechanical Engineering

Submitted To: Submitted By:

Mr. Sandeep Jhamb SANJAY NIRANIA

Head of Department Roll No.11EAIME053

Department of Computer Science &Engineering

Arya Institute of Engineering & Technology, Jaipur

Rajasthan Technical University, Kota



Candidate’s Declaration

I hereby declare that the work, which is being presented in the practical training seminar,

entitled “BALL BEARING DIVISION” in partial fulfillment for the award of Degree of

“Bachelor of Technology” in Mechanical Engineering, submitted to the Department of

Mechanical Engineering, Arya Institute of Engineering & Technology, Rajasthan Technical

University is a record of my own work carried under the Guidance of Mr.ADITYA

SHAHANI, (NATIONAL ENGINEERING INDUSTRIES LIMITED).

I have not submitted the matter presented in this Report anywhere for the award of any other

Degree.

(Signature of Candidate)

SANJAY KUMAR NIRANIARoll No.: 11EAIME053

AcknowledgementMechanical Engg. Deptt. A.I.E.T., Jaipur


We wish to express our deep sense of gratitude to our Practical Training Guide Mr. ADITYA

SHAHANI, (NATIONAL ENGINEERING INDUSTRIES LIMITED) for guiding me

from the inception till the completion of the project. We sincerely acknowledge him/her for

giving his/her valuable guidance, support for literature survey, critical reviews and comments

for our Project.

We would like to first of all express our thanks to Dr. Arvind Agarwal, Chairman of Arya

Main Campus, for providing us such a great infrastructure and environment for our overall

development.

We express sincere thanks to Prof (Dr.) R C Bansal the Principal of AIET, for his kind

cooperation and extendible support towards the completion of our project.

Words are inadequate in offering our thanks to Er. Sandeep Jhamb, H.O.D of ME

Department, for consistent encouragement and support for shaping our project in the

presentable form.

We also express our deepest thanks to Er. Gurmeet Singh for his support in providing

technical requirement and fulfilling our various other requirements for making our project

success.

We also like to express our thanks to all supporting ME faculty members who have been a

constant source of encouragement for successful completion of the project.

Also our warm thanks to Arya Institute of Engineering & Technology, who provided us this

opportunity to carryout, this prestigious Project and enhance our learning in various technical

fields.

SANJAY KUMAR NIRANIA

Roll. No:-11EAIME053



ABSTRACT

This papar present detail of a computer interface developed for vibration monitoring and

diagnostic of ball bearing based on experiments conducted for bearing fault diagnosis. An

experiment setup was designed and fabricated for testing various ball bering to obtain their

vibration chracteristics – three defect – free and nine defective tapered roller bearing with

outer race defects ,ball defects. The bearing vibration data were acquired using NI DAQ and

lab view virtual instrumention software, which were futher processed using computer

interface used various time and frequency domain parameters like peak to valley, RMS

value,kurtosis envelope analysisetc.

CONTENT



Title Page No.

Cover Page…………………………………………………………….....................................1

Certificates(Company & college)…………………………………………………………….2

Candidate declaration………………………………………………………………………...4

Acknowledgement……………………………………………………………………………..5

Chapter 1 INTRODUCTION………………………………………………………….10-15

1.1. Company profile 10

1.2. Milestones 11

1.3. Technical collaboration 12

1.4. Main Customers 12

1.5. Manufacturing Facilities 13

1.6. BEARING INDUSTRY INDIAN SCENERIO 15

CHAPTER 2 ABOUT NEI………………………………………………………….....16-17

2.1 Products 16

Chapter 3 BEARING…………………………………………………………………...18-25

3.1 TYPES OF BEARING 18

3.2.1 Single Row Radial Ball Bearings 21

3.2.2 Single Row Radial Ball Bearing with Tapered Bore 22

3.2.3 Single Row Angular Contact Ball Bearing 22

3.2.4 Single Row Externally Aligning Ball Bearing 23

3.2.5 Double Row Self Aligning Ball Bearing 23

3.2.6 Double Row Self-Aligning Ball Bearing withTapered Clamping Sleeve and Nut23

3.2.7 Thrust Ball Bearing 23

3.2.8 Cylindrical Roller Bearing 23

3.2.9 Tapered Roller Bearing 24

3.2.10 Spherical Roller Bearing 25



CHAPTER 4 COMPONENT OF BALL BEARING………………………………….26-28

4.1 Bearing races 27

4.2 Types of bearing races 27

4.3 Raw material 27

4.4 Outer & inner races 27

4.5 Cages 28

4.6 Balls 28

CHAPTER 5 MANUFATURING PROCESS OF BALL BEARING………………29-43

5.1 Heat treatment process 30

5.2 Hardning process 34

5.3 Different process &Machines 36

5.4 Face grinding 36

5.5 OD grinding 36

5.6 Laser marking system 38

5.7 Grinding 39

5.7.1 Centerless grinding 39

5.7.2 Types of centerless grinding 41

5.7.3 Throughfeed centerless grinding 41

5.7.4 Infeed centerless grinding 42

5.7.5 Endfeed centerless grinding 43

CHAPTER 6 BALL ASSEMBLING PROCESS……………………………….……..44-50

6.1 Wire 45

6.2 Heading 45

6.3 Flashing 46

6.4 Grinding 47

6.5 Heat treatment 48

6.6 Tumbling 49

6.7 Lapping 49

6.8 Cleaning 49

LIST OF FIGURES



1.1 MILSTONES OF NEI 11

1.2 NEWAI PLANT 14

1.2 MENASAR PLANT 15

3.1 SINGLE ROW RADIAL BALL BEARING 22

3.2 SINGLE ROW RADIAL BALL BEARING 22

3.3 TAPPER BORE 24

3.4 CYLINDRICAL ROLLER BEARING 25

3.5 TAPPERED ROLLER BEARING 25

4.1 COMPONENT OF BALL BEARING 26

5.1 CHUGAIRO FURNANCE 31

5.2 SALT BATH FURNANCE 36

5.3 CENTRELESS GRINDING 39

5.4 MECHANISM OF CENTRELESS GRINDING 40

5.5 THROUGH FEED GRINDING 41

5.6 DIMENSION OF THROUGH FEED GRINDING 42

5.7 INFEED GRINDING 43

5.8 ENDFEED GRINDING 43

6.1 WIRE 45

6.2 HEADER MACHINE 46

6.3 GRINDING MACHINE 47

6.4 HARD GRINDING MACHINE 48

6.5 CLEANING MACHINE 50

7.1 OUTER RACE GRINDING 51

7.2 DIAMOND TIP ALLIGNMENT 52

LIST OF FLOW CHART1 MANUFATURING PROCESS OF BALL BEARING 29

2 HEAT TREATMENT PROCESS 33

3 ASSEMBLING PROCESS 44

CHAPTER 1



INTRODUCTION

1.1. COMPANY PROFILE:-

The renowned industrialist, late Shree B. M. Birla founded National Engineering Industries

Ltd., Jaipur in the year 1946 as a pioneer industry in the field of bearing manufacture, under

the name of "National Bearing Company Ltd."

The first bearing was manufactured in 1950 with a modest start of 30,000 bearings in 19 sizes.

The company is now manufacturing nearly 3.8 million bearings per month in over 500

different sizes ranging from 6 mm bore to 1300 mm outer diameter and has the capacity to

manufacture bearings upto 2000 mm outer diameter. At NEI, the development of bearings is a

never ending job. With ever increasing activities and grant of industrial licenses for other vital

industries and manufacturing of Roller Bearing Axle Boxes for Railway Rolling Stock, Steel

Balls, Tapered Roller Bearings, Spindle Inserts etc., the name of the company was changed in

1958 to "National Engineering Industries Ltd." retaining its original trade mark NBC.

The industry is spread over 118 acres of land in Jaipur and 56 acres in Gunsi (Newai). This is

the only unit in the country manufacturing wide variety and range of bearings such as Ball

Bearings, Steel Balls, Tapered Roller Bearings, Cylindrical Roller Bearings & Axle Boxes for

Railway Rolling Stock including Spherical Roller Bearings, Cartridge Tapered Roller

Bearings and Large Diameter special Bearings in separate fully equipped factories. The

development of National Engineering Industries Ltd., was pioneered with a theme

“Indigenization and Self-reliance".

NBC Bearings are widely used by 2 and 3 Wheelers, Cars, Trucks, Tractors, Electric Motors,

Railway wagon, Coach and Locomotive manufacturers as Original Equipment and Steel Mills,

Heavy Engineering Plants, Bulldozers, Shovels, Tillers and Thermal Power Plants all across

the country.

1.2. Milestones



Fig.1.1 Milestones of NEI

i. 1946 -Company established as National Bearing Company (NBC) under technical

collaboration with Hoffman, U.K.

ii. 1950 Ball Bearing Production started.

iii. 1958 Company is renamed National Engineering Industries Limited (NEI); NBC

Trademark retained.

iv. 1967 Tapered Roller Bearing production started

v. 1975 Spherical Roller Bearings production begins

vi. 1981 Second Plant inaugurated in Newai.

vii. 1982 Cartridge Tapered Roller Bearing in Technical Collaboration with Brenco

Incorporated of U.S.A.

viii. 1985 Technical Collaboration with NTN Corporation of Japan for Ball, Cylindrical &

Spherical Roller Bearing.

ix. 1995 ISO - 9001 Quality Management System Certification

x. 1996 Technical collaboration with Izumi Kinzoku Kogyo Co. Ltd., Japan for Machine

Retrofitting

xi. 2007 Third Plant inaugurated in Manesar.

xii. 2008 NBC receives TPM Excellence Award



xiii. 2010 NBC receives Deming Award

xiv. 2012 NBC receives the ACMA awards for Manufacturing and Technology Excellence

1.3. Technical collaboration

(i) BRENCO Incorporated of U.S.A. Since 1982 - For Cartridge Tapered Roller Bearings for

railroad applications.

(ii) NTN Corporation of JAPAN Since 1985 - For Ball Bearings, Cylindrical & Spherical

Roller Bearings, JPU Bearings, Double Row Angular Contact Bearings, Hub Bearings Since

1997 - for Tapered Roller bearings.

(iii) Izumi Kinzoku of JAPAN Since 1996 for remanufacturing, retrofitting and overhauling of

Grinding and Super-finishing machines for bearing races.

1.4. Main Customers

Rolling Stock: -

DLW (Diesel Locomotive Work)

CLW (Chittaranjan Locomotive Works)

ICF (Integral Coach Factory, Chennai)

RCF (Rail Coach Factor, Kapurthala)

CIMMCO

BEML (Bharat Earth Movers, Bangalore)

TEXMACO

Hindustan Motors Ltd.

Maruti Udyog Ltd.

Mahindra & Mahindra

Automobiles-LCV: -

Ashok Leyland

Force Motors

Eicher Motors

Tata Motors

Automobiles-Two/ Three Wheelers:-

Bajaj Auto Ltd.

Hero Honda Motors Ltd.



Honda Motorcycle & Scooters India Ltd.

Suzuki Motorcycle India

Majestic Auto

Piaggio India Ltd.

Royal Enfield Ltd.

Yamaha Motors India Pvt. Ltd.

TVS

Tractors: -

Eicher

Escorts

HMT

International tractors

Mahindra & Mahindra

Punjab Tractors

TAFE

VST Tillers

Electric Motors & Pumps:-

Crompton Greaves

G.E. Motors

Kirloskar Electric

NGEF

MICO

Fans: -

Bajaj Electricals

Crompton Greaves

1.5. Manufacturing Facilities-

NBC has manufacturing facilities at Jaipur (established in 1946), Newai (established in 1980)

and Manesar (established in 2006). A fourth plant, a green field project, at Savli in Gujarat

will ship out its first bearing in November 2013, ramping up production capacity to 150

million bearings per year once it is fully operational.



Jaipur Plant

Newai (Gunsi) Plant

Manesar Plant

1.5.1. Newai (Gunsi) Plant-

Established in the year 1980-81 as an expansion project of NEI Ltd . The factory is equipped

with fully automated grinding lines with electronic in-process & post- process gauging and

centrally air-conditioned assembly lines with auto gauging and test equipments for quality and

reliability of

the

products,

The plant is

spread

over a

covered

area of

7,200 Sq.

Meters.

Fig1.2: Newai (Gunsi) plant

1.5.2 Manesar Plant



NEI has set up its third Ball Bearing manufacturing plant in the fastest growing industrial

town of Manesar in Haryana. The plant is having a covered area of 5200 sq. meters. with

the most advanced and sophisticated machines imported from reputed manufacturers from

Europe and Japan .This plant is equipped with state of the art fully automated grinding

lines, assembly lines and inspection equipments.

Fig1.3: Manesar Plant

BEARING INDUSTRY INDIAN SCENERIO :

The Indian Bearing Industry is estimated at Rs. 30 BillionApproximately. The Industry has

established a highlydiversified product range of around 1000 type of Bearing,having High

Volume Demand. As much as 70% of the total

Demand for common varieties and size of bearing is met by the domestic Industry, and the

remaining demand to the tune of 30% is imported essentially for Industrial Application

andspecial purpose.

The Indian bearing Industry can be divided in to theorganized sector and un-organized sector.

The organized sector primarily caters to the original equipment Manufacturer (OEM)

Segment, which predominantly comprises Automotiverailway and other Industrial users. The

replacement market is dominatedby unorganized Sector.



CHAPTER 2

ABOUT NEI

National Engineering Industries(NEI) Ltd was established 150 year ago by multi-billion dollar

C.K. Birla group. It manufactures a wide range of maximum types of bearings bearings for

automotive and railway industry as well as for general industrial applications under the brand

name NBC . NEI was founded in the year 1946 as a pioneer industry in the field of bearing

manufacture. Now it manufactures nearly 80 Million Bearings per annum in over 500

different sizes ranging from 6 mm bore to 1300 mm outer diameter, also having capability to

manufacture the bearings upto 2000 mm as outer diameter.

NEI is one of the largest domestic bearing manufacturing company with gross annual

turnover of Rs 1051 crore in 2010-11.The company exports bearings to more than 20

countries and is also exporting to OEMs in Europe and USA.

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.

Union of Japanese Scientists and Engineers (JUSE), Japan, for achieving distinctive

performance improvement through the application of Total Quality Management (TQM).The

Deming medal confirms that our quality management systems are one of the

best ,globally .For our customers, this means they were enjoying the consistently superior



products and assurance of highest quality for every NBC bearings theyuse .

2.1 Products:-

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. These products with

approx. 2300-strong team, supported by a well-equipped R&D with bearing life testing

facilities. The products are:-

Ball Bearings

Tapered Roller Bearings

Cylindrical Roller Bearings

Axle Boxes Spherical

Roller Bearings

Cartridge Tapered Roller Bearings

Large Dia Special Bearings



CHAPTER 3

BEARINGA bearing is a device to allow constrained relative motion between two or more parts,

typically rotation or linear movement. Bearings may be classified broadly according to the

motions they allow and according to their principle of operation as well as by the directions of

applied loads they can handle

3.1 Types:-

There are many different types of bearings.

Type Description FrictionStiffnes

s†Speed Life Notes

Plainbearing Rubbing

surfaces,

usually with

lubricant;

some

bearings use

pumped

lubrication

and behave

Depends

on

materials

and

constructio

n, PTFE

has

coefficient

of friction

Good,

provide

d wear

is low,

but

some

slack is

normall

y

Low to

very

high

Low to very

high -

depends upon

application

and

lubrication

Widely used,

relatively high

friction, suffers

from stiction in

some applications.

Depending upon

the application,

lifetime can be

higher or lower


http://en.wikipedia.org/wiki/Moving_parts


similarly to

fluid

bearings.

~0.05-

0.35,

depending

upon

fillers

added

presentthan rolling

element bearings.

Rollingelementbe

aring

Ball or

rollers are

used to

prevent or

minimize

rubbing

Rolling

coefficient

of friction

with steel

can be

~0.005

(adding

resistance

due to

seals,

packed

grease,

preload

and

misalignm

ent can

increase

friction to

as much as

0.125)

Good,

but

some

slack is

usually

present

Modera

te to

high

(often

require

s

cooling

)

Moderate to

high

(depends on

lubrication,

often requires

maintenance)

Used for higher

moment loads than

plain bearings with

lower friction

Jewel bearing Off-center

bearing rolls

in seating

Low Low

due to

flexing

Low Adequate

(requires

maintenance)

Mainly used in

low-load, high

precision work

such as clocks.

Jewel bearings



may be very small.

Fluid bearing

Fluid is

forced

between two

faces and

held in by

edge seal

Zero

friction at

zero

speed, low

Very

high

Very

high

(usuall

y

limited

to a

few

hundre

d feet

per

second

at/by

seal)

Virtually

infinite in

some

applications,

may wear at

startup/shutd

own in some

cases. Often

negligible

maintenance.

Can fail quickly

due to grit or dust

or other

contaminants.

Maintenance free

in continuous use.

Can handle very

large loads with

low friction.

Magnetic

bearings

Faces of

bearing are

kept

separate by

magnets

(

electromagn

ets or

eddycurrent

s)

Zero

friction at

zero

speed, but

constant

power for

levitation,

eddy

currents

are often

induced

when

movement

occurs, but

may be

negligible

if

Low No

practica

l limit

Indefinite.

Maintenance

free. (with

electromagne

ts)

Active magnetic

bearings (AMB)

need considerable

power.

Electrodynamicbea

rings (EDB) do not

require external

power.



magnetic

field is

quasi-

static

Flexure bearing

Material

flexes to

give and

constrain

movement

Very low LowVery

high.

Very high or

low

depending on

materials and

strain in

application.

Usually

maintenance

free.

Limited range of

movement, no

backlash,

extremely smooth

motion

†Stiffness is the amount that the gap varies when the load on the bearing changes, it is distinct

from the friction of the bearing.

3.2 TYPES OF BEARING:

3.2.1 Single Row Radial Ball Bearings

The initial technology was from Hoffman Manufacturing Company Ltd., U.K. a collaboration,

which continued for 20 years.

We offer a wide range of both metric and inch series deep groove ball bearings, angular

contact ball bearings, self-aligning ball bearings etc.

With our tie up with the world's leading bearing manufacturing company NTN Corporation,

JAPAN, we have gained access to the most advanced ball bearing technology i.e. thermo

mechanical bearings (TMB) and tensioner bearings available today and our wide range of ball

bearings is increasing under this collaboration.



Fig. 3.1 Single row radial ball bearing

3.2.2 Single Row Radial Ball Bearing with Tapered Bore

The single row radial ball bearings with tapered bore are Identical to single row radial ball

bearings except that these have tapered bore which is used for easier mounting and for the

adjustment of radial clearance. Dimensions of tapered bore diameter refer to small bore.

Fig. 3.2 single row radial ball bearing with tapered bore

3.2.3 Single Row Angular Contact Ball Bearing

The single row angular contact ball bearings have higher axial load capacity than the single

row radial ball bearings. The radial load must always be less than axial load.The bearings can

carry axial load in one direction only andshould be adjusted against another bearing, if axial

load iscoming from both the directions.

Each bearing can be located endwise in one direction only.

3.2.4 Single Row Externally Aligning Ball Bearing

The single row externally aligning ball bearings are usedwhere accurate alignment cannot be

guaranteed betweenbearing positions. It can take radial loads. Axial loads can also be

accommodated.The shell housing must not be made an interference fit on their outside



diameter. If an interference fit is used, the shell housing may contract and prevent

alignment.These bearings can be located endwise in both the directions.

3.2.5 Double Row Self Aligning Ball Bearing

The double row self-aligning ball bearings have the common outer spherical race for both the

rows. This feature gives the bearings self-aligning properties. The bearings have the same

external dimensions as there equivalent single row radial ball bearings. They can take radial

loads and very light axial loads.They can be located endwise in both the directions.

3.2.6 Double Row Self-Aligning Ball Bearing withTapered Clamping Sleeve

and Nut

The double row self-aligning ball bearings with tapered clamping sleeve and nut are identical

to double row self-aligning ball bearing except that these have a tapered bore, which is used

for easier mounting and also a clamping sleeve and nut to clamp the bearings on the shaft. The

tapered bore is also used for the adjustment of radial clearance.

3.2.7 Thrust Ball Bearing

The thrust ball bearings are used for high axial loads at low speeds. These cannot operate at

high speed as it will give rise to centrifugal or radial forces which cannot be taken by the

bearings.

They can be located endwise in one direction only.

3.2.8 Cylindrical Roller Bearing:

The cylindrical roller bearings have greater radial load capacity than ball bearings of same

external dimensions and are particularly suitable for arduous duties. The bearing features a

modified line contact between rollers and raceways toeliminate edge stressing. These bearings

have a high radial load capacity and are suitable for high speeds. Due to detachabledesign

character they have advantage of mounting inner ring and outer ring separately.



Fig. 3.3 Cylindrical roller

bearing

3.2.9 Tapered Roller Bearing

Tapered roller bearings are designed in such a way that vertices of the cone for each roller and

those for the inner and outer raceways coincides on the bearing axis or extensions of the

raceways and rollers converge at a common point on the axis of rotation. This results in true

rolling motion of the rollers on the raceways at every point along the rollers.

The tapered roller bearings support radial loads and axial loads from one direction only. The

line contact between rollers and raceways provide the bearings with a high load carrying

capacity. Steep angle tapered roller bearing with exceptionally steep cone angle enables the

bearings to take heavier axial load.

The bearings are of separable type, enabling separate mounting of cups and cones.

Since the tapered roller bearings can absorb thrust loads in one direction only, these bearings

should generally be installed as opposed mountings. The correct amount of radial and axial

clearance is obtained by adjusting the two bearings against each other.

Besides, double row and four row tapered roller bearings are also widely used for heavy loads

such as rolling mills.



Fig. 3.4 tappered roller bearing

3.2.10 Spherical Roller Bearing

Spherical roller bearings are particularly suitable for carrying heavy loads. They are usually of

the double row design, both of the rows of the rollers having common spherical raceways in

the outer ring. This feature of this bearing has great practical importance in those cases where

it is difficult to obtain exact parallelism between the shaft and housing both axes. So these

bearings are suitable where misalignment can arise from mounting errors or from deflection of

the shaft.



Fig 3.5 Spherical roller bearing

CHAPTER 4

COMPONENT OF BEARING

There are four major parts to a standard ball bearing: the outer race, the rolling balls, the inner

race, and the cage or retainer.



Fig. no. 4.1 component of ball bearing

4.1 BEARING RACE'S

The SSI Races Manufacturing Units of Jaipur areManufacturing outer & Inner Bearing Races

in Different sizes.According to the Demand in the market. The turned Races aresupplied in

Soft condition and remaining operation of Hardening, Tempering Grinding &

Honing/polishing are beingdone by the Bearing Manufacturer.

The Detail of type and size of Bearing Races are as under:-

4.2 Type of Bearing Races Inner Dia Ranger

1. Ball Bearing Races: 10mm to 80mm

2. Roller Bearing Races: 17mm to 100 mm

3. Cylindrical Roller Bearing Races: 20mm to 75 mm

4. Special type of Bearing Races for: 20mm to 75 mm



Transport Vehicles (Thrust Bearing)

5. Axle Box Bearing Races for Railway: 100mm to 200 mm

4.3 RAW MATERIAL:

The Races & Rolling elements of Bearing are subjected tostress on a very small contact

surface must be of such materialso as to with stand wear and have high elastic Limit & fatigue

Limit. The raw material being used by the Industry forManufacturing of various Bearing

components are as under:

4.4 Outer and Inner Races

The raw material used in the Manufacturing of bearingRaces is SAE 52100 high Carbon

Chrome bearing steel, whichhas composition similar to EN-31 (100 CR 6 As per

BISspecification). The raw material for Bearing Races is in the formof Rods & Seamless

Hollow Tubes. This is a SpheroidsAnnealed Steel. Approx. 80% of the Seamless Hollow

tubes arepurchased by the Industry from M/s. Indian Seamless Metal tubePUNE, while the

rest of the tube used in the cluster is importedmaterialThe Steel bar are purchased from M/s.

Indian SeamlessSteel & Alloy Pune & M/s. Mahindra Ugine Steel CompanyKHAPOLI

(Maharashtra). Some of the units are buying the steelscrap rod for manufacturing bearing

races.

Bearing Races material and their heat treatment arerequired to be selected carefully, taking

account the mechanicalstrength and required life of the Bearing, so that each materialmay

perform at maximum capability.Approximate required composition for bearing races

areConstitute % Composition

Carbon 0.95 to 1.1

Chromium 1.4 to 1.6

Manganese 0.50 max.

Silicon 0.15 to 0.35



Sulphur 0.025 (Max.)

Phosphorous 0.05

4.5 CAGE'S

Cage is used to return balls at proper distance to preventthem from containing each other and

to prevent a temp.rise and resultant damage due to friction.

The Material for manufacturing cages is CRCA Strips ofC2015 Bearing grade steel having

carbon percentage at0.08% max. and Magnesium ranging from 0.25% to 0.45%

4.6 BALL'S

Steel Balls of grade 20, 16 &10 with close tolerance,smooth surface made by using SAE

52100 High CarbonChrome Bearing Steel.

CHAPTER 5

MANUFACTURING OF BALL BEARING

MANUFACTURING PROCESS OF BALL BEARING:

Forged rings (De-scaled) as raw material

(SAE 52100 steel)

↓

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

Flow chart 1 Manufacturing process of ball bearing

Heat Treatment Process:-

Heat treatment process is the process of hardening the soft material. The row material is soft

material and it has to be hardened before grinding, and hardening increase the life of bearing.

Hardening is done in a special furnace named CHUGAIRO furnace. The soft machined

material is feed in the furnace and washed at 600 C, then send to a chamber where the material

heated in four chambers the first chamber has the temperature 8400 C and further chamber

contains the 8500 C temperature. Then it dipped into an oil tank at temperature 250C 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 is obtained.

The systematic flowchart is shown in following fig.



Fig 5.1 Chugairo Furnance

Reference: http//www.nbcprojectreport.com



Reference: http//www.heattreatmentprocess.com

Heat Treatment

Raw Material

(Carbon Steel)

Carburizing

(Carbon Shield Layer increases Hardness)

(10 – 12 hrs.) (940 0C) (GC Furnace)

Hardness I

(Revolving Furnace)



(920 0C) (Time Dependent on Job)

Annealing

(6 hrs.) (650 0C)

Shot Blasting

Hardening II

(Revolving Furnace)

(820 0C) (Time Dependent on Job)

Sub-Zero Treatment

(-60 0C) (Increases Toughness)

Tempering

(160 0C) (4 hrs.)

Shot Blasting

(Wheel Abrator)

Hardness Inspection

(60 HRC)

Flow chart 2 heat treatment



After heat treatment following process are done to get a new ready to use ball bearing.

Hardening Procedure

Steel Material Carbon (0.9% - 1.10%)

HC Steel (High Carbon Steel)

Process Hardening Quenching Tempering

Air

Cooling

Procedure

Heat the

Furnace

850-870O C

Fast cooling

600 C – Oil

Quenching

1800C – Salt Bath

Furnace

Heating

1650-1800C

Cool at Room

Temperature

Hardness ------ 62 – 66 HRC 60 – 64 HRC ------

Time 35-60 min.

According to

5-15 min. 150 min. ------



the job

Hardening Procedure

Steel Material

LC Steel (Low Carbon Steel)

Process Carburizing Hardening Quenching Tempering

Procedure

Carbon Furnace

heating at

9400 C - 9500 C

Furnace

temperature at

8500 C – 8700 C

Fast cooling 600

C –for oil

quenching only

Heat the

Furnace at

1650 C-1800 C

Hardness .200 - .250 ------ 60 – 64 HRC 52 – 62 HRC

Time 8 – 10 hours 35-60 min.

According to

the job.

5-15 min. 120-180 min.

Salt Bath Furnace



Reference : http//www.superheatfurnance.com

FIG NO. 5.2 SALT BATH FURNANCE

Different process and Machines:-

Face Grinding:-

Face is the surface at side of the inner and outer race , face should be finished indeed to get the

desire width of the bearing and since the 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 grinding wheel.

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 assembled in machine. It is obtain in an OD grinding

machine in this machine the outer race is rotated between two grinding wheel.The outer race

is passed in machine two times to get highly finished. First rough and second highly finished.

At G-12 line the different machines.

Job No. 6211

G-114 Outer race track grinding machine.

G-115 Outer race track honing machine.



G-103 Inner race bore grinding.

G-343 Inner race track grinding.

G-363 Inner race face grinding machine.

G-344Inner race track honing machine.

Assembly Line:-

A-439Auto inner outer race washing m/c.

A-440Auto inner outer race measuring m/c.

A-441Auto inner outer race combining m/c.

A-442Auto cage assembly m/c.

A-443 Auto demagnetizing m/c.

A-444Auto washingm/c for semi-finished product.

A-445Shower cleans.

A-446 Autoinner outer diameter inspection and sensitivity checking m/c.

A-447 Auto radial internal clearance inspection m/c.

A-448Autowashing and drying m/c.

A-449 Auto double side vibration testing m/c.



A-450 Auto Greasing and weighing m/c.

A-451 Auto shielding m/c.

A-452 Auto conservation oil spraying and visual inspection m/c.

Laser Marking System:

A Laser marking system marks a highly visible mark on the job without touching it.

Job Number

NBC INDIA

Date Code

Important parts

a) Marker

b) Controller

c) Water-cooled Unit

d) Filter Kit

e) Console

f) Control Panel

g) Mechanical Handing System

The Laser is produced with the help of a diode which is focused on the job by using a lens.

The Laser beam produces a external high thermal energy; this thermal energy marks a dark

mark on the job extra thermal energy is then absorbed through the cooling system.



Thus, in this form the laser beam produced from a diode marks a dark mark on the job. With

the help of the machine customerrequirements like; customer code, part number etc. can be

marked according.

GRINDING

Centre less Grinding

Fig 5.3 Centerless Grinding

Centerless grinding is a method of material removal through grinding, similar to centered

grinding except for the absence of the spindle. It has high throughput, i.e. a large number of

parts can be manufactured in a short time.

The workpiece is set up between the regulating wheel (or back up wheel) and the grinding

wheel, and is supported by the work blade (or work rest). The work rest is located between the

wheels. The work is placed upon the work rest, and the latter together with the regulating

wheel is fed forward forcing the work against the grinding wheel. Axial movement of the

work past the grinding wheel is accomplished by tilting the regulating wheel at a slight angle

from horizontal. An angular adjustment of 0 to 8 or 10 degrees is provided in the machine for

this purpose.

Centerless grinding is classified into two types:


http://en.wikipedia.org/wiki/Grinding_(abrasive_cutting)


Throughfeed grinding - the workpiece is fed into the machine along the work blade

Plunge grinding - the workpiece is placed between the wheels on a work blade and the

grinding wheel is plunged into the workpiece.

Some of the benefits of centerless grinding include the ability to grind parts with geometries

that do not allow them to be OD ground, the ability to remove three, five and other odd

numbered lobing on the shaft of a part, and to maintain size beyond what is typically capable

of an OD grinder due to the low overall pressures spaced out along the workpiece.

An example of a centerless ground application is the outer diameter of the bearing races.

Mechanism:

Fig no 5.4 Mecanism of centerless grinding


http://en.wikipedia.org/wiki/Race_(bearing)


Types of Centerless grindings

There are three main types of centerless grinding:

1. Through-feed grinding.

2. In-feed grinding.

3. End-feed grinding.

Through-Feed Grinding

In through-feed grinding, the part rotates between the grinding wheel and a regulating wheel

as shown below.

Fig. no. 5.5 Through feed grinding

For through-feed grinding, one or both wheels of the centerless grinding machine are canted

out of the horizontal plane, as shown below. This imparts a horizontal velocity component to

the work piece, so that outside feed mechanisms are not necessary.

The grinding wheel is canted with respect to the other two axes so that a component of its



surface velocity pushes the part in the direction shown below. This auto feeding characteristic

is useful for rapidly processing many parts in quick sequence.

Because of the axial movement, through-feed parts can only have right circular cylindrical

ground surfaces. The wheel cannot be dressed to grind more complex shapes.

Below are parts produced with the through-feed centerless grinding process. As can be seen

from the quantities produced, through-feed grinding is primarily a mass-production process

because of its high throughput.

Fig. no 5.6 Dimensios Of through feed grinding

In-Feed Grinding

In-feed grinding differs from through-feed grinding in that the part is not fed axially so that

the ground surface does not need to be a right circular cylinder. The grinding wheel can be

dressed to accomodate the part. Once the work piece part is in place, the grinding wheel is fed

in radially.

Because of the set up time involved for each part, in-feed griding does not have the high



throughput of through-feed grinding. In-feed grinding is illustrated below.

Fig, no. 5.7 infeed grinding

End-Feed Grinding

In end-feed grinding, the part moves in axially between the grinding wheels, stops for

grinding, and then moves out again. The wheel can be dressed to form more complex shapes,

but the part can only get progressively smaller in diameter. End-feed grinding is illustrated

below.

Fig. no. 5.8 End feed grinding

CHAPTER 6



ASSEMBLING PROCESS

BALL ASSEMBLING PROCESS:-

Forged wire(De-scaled) as raw material

(SAE 52100 steel)

↓

Heading Operation

↓

Flashing

↓

Grinding

↓

Heat treatment

↓

Hard Grinding

↓

Tumbling

↓

Lapping

↓

Washing

↓

Testing and Fine Inspection

↓

Packing and launching

Flow chart 4 Assembling Process



1. WIRE

Fig. no. 6.1 Wire

2. HEADING PROCESS:-

Heading is the process in which the wire of suitable dia is pressed b/w two dies one is

fixed and another is reciprocating moveable die. That die works at slider crank

mechanism.

The process is known as heading due to formation of head and flash as the extra metal. The

extra metal remains due to passes between two dies. Use of head and flash is to assure that

the formed ball is completely filled and fully solid with metal.



Fig. no. 6.2 Header machine

3.FLASHING:-

The flashing is the operation in which we remove the flash on the ball having head and flash.

It is also a grinding operation.The wheels are used are coarse grain type. The time taken in

flashing is18hrs approx.



Fig. no. 6.3 Flashing

3. GRINDING:-

After flashing balls are send to grinding machines.Soft grinding process are used to finish the

ball to remove the major defect the balls are now begain to take shape but not fully finished.

Fig. no .6. 4 grinding machine



4.HEAT TREATMENT:-

The grinded ball are soft due to many operation like heading, flashing, grinding performed

earlier so by using Chugai RO furnace . The heat treatment is been done by which the balls

are hardened and the hardened balls capable to have loading at it for along time. Thegas used

in heat treatment is Indo Gas which is mixture of LPG & Air.In the heat treatment there are 3

steps.

• Heating

• Quenching

• Tempering

• The process time is approx 3 hrs.

5.HARD GRINDING:-

The heat treated balls are then send to hard grinding where is the extra metal are remove. It is

also a similar operation like a soft grinding but the wheel used is harder than the soft grinding

machine. The process time is approx 3hrs.

Fig. no. 6.5 hard grinding machine



6. Tumbling :-

Tumbling is the process is which the hard grinded balls are washed in a slower process in

emulsion and at here the defective ball are removed from the lot.

7. Lapping :-

It is also a metal removal process in which the balls are finished very well. The metal removal

is very less in order to microns. The wheels which are used are finer grain sized and the

friction agent between the balls is abrasive paste of hollino oil. The lapping operations

are of two types.

Lapping-1:-

The lapping-1 is the process in which the diameter of balls is reduces in order to micron.

The finishing of balls are very high. The dB values, tally round, surface finish, parameters are

acheive. The process time is 36hrs

Lapping-2-3:-

The lapping 2-3 is the operation in which the dia is not reduced so much but the surface finish

is increased very much. The polish is used instead of abrasive paste so the friction is

less. The process time 24hrs.

8.CLEANING:-

In this process the finished balls are washed in Kerosene Oil for approx 1hr.



Fig. no. 6.6 Cleaning machine

9.TESTING:-

In the testing we test each ball individually. Three test are performed at each ball

• ECT – eddy current test

• EOT – optical test

• EVT – vibration test

The test in case of failure the ball is rejected and the cause of failure is discontinuity in

internal structure.

10.FINE INSPECTION:-

In this segment the each ball is inspected by human eyes the surface defect are inspected by

that means.



CHAPTER 7

PROBLEM STUDIED DURING TRAINING:-

Ball Bearing Grinding

Problem No. 1:-

G-1 Line Job No. 6213 (outer race of bearing)

Machine No. G-241

The abnormal lines were seen at the face of job. Initial prediction was that the backing plate is

damaged. The backing plate is part of machine which holds the job during grinding process at

rotates the job against the grinding wheel. The backing plate has worn out because it has

friction and relative motion between job, when it hold the job.

The backing plate has certain limit to wear about 3 mm. Scratches occur on the face of

backing plate which further produce the lines on the job face. The backing plate holds the job

as shown in fig.

Fig. no. 7.1 outer race grinding



The backing plate supports the job at the back side.

The backing plate and the shoe and shoe fixture was replaced.

But the wowel was found in the job rotation, the shoe is the device which supports the job at

bottom and one side during the grinding process. And shoe fixture fixes the shoes.

The woweling was produced due to the carbide tip was damaged when the disassembling the

backing plate.

Problem No. 2:-

G-1 Line Job No. 6213 (Inner race track grinding)

Machine No. G-245

Inner race track grinding wheel changed because the wheel was has completed its life and not

able further use. Then it dressed for curvature setting as normally it dressed. But the black and

hot job obtained at outlet of machine. The prediction is that the dressing of wheel was not

done properly and curvature is not settled for job. Then prediction was that diamond has

finished then it was changed. New diamond setted and then dressed the grinding wheel but the

curvature was not right then and job was heated. Then again wheel dressed and job obtained

satisfactory

But the diamond has to be changed very frequently, and curvature was not satisfactory. The

problem was that the diamond position was not right the right position is shown in the

following fig.



Fig 7.2 diamond tip alignment

Problem No. 3:-

G-1 Line Job No. 6213 (Inner race track grinding)

Machine No. G-245

The machine was taking more cycle time to grind the job. The machine was checked no

problem was found. Then the ovality checked of input job then it was found about 100 to 300

micron. Then 100 random pieces were checked then it was found the ovality was more than

the standard limit. When the ovality is more the wheel has to remove more material From

job.Hence increased cycle time.

Ovality occurs when the job heat treated. And it can be controlled.

Problem No. 4:-

G-1 Line Job No. 6213 (outer race track grinding)

Machine No. G-252

The track center of the outer race was found varied from the standard dimension. Initially the

lock nut to be adjusted, it was found that there was ply in the lock nut and the lock nut was

damaged due to hammering. The new lock nut was prepared in the tool room and fitted in the

machine. Now the track center adjusted.

Problem No. 5:-

G-12Line Job No. 6

211 (Inner race track Honing)

Machine No. G-343

Job rotation problem was found. It was due to the band in the window.

Window is the holding device for the honing stone and ‘O’ ring. The band was due to

hammering action of the arbor.


Nbc Training Report - ball bearing division

Documents

Transcript of Nbc Training Report - ball bearing division