Training Report of NBC Bearing

Project report on training in National Bearing Company ENGINEERING PROJECT REPORT ON INDUSTRIAL TRAINING IN NATIONAL BEARING COMPANY

FOR THE PARTIAL FULFILLMENT OF THE REQUIREMENT OF BACHELOR OF TECHNICAL EDUCATION SUBMITTED BY KETAN TOSHNIWAL IV YEAR, MECHANICAL ENGINEERING A2 – BATCH, ROLL NO  ME052

GYAN VIHAR SCHOOL OF ENGINEERING & TECHNOLOGY 1

Project report on training in National Bearing Company JAIPUR

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Project report on training in National Bearing Company

TABLE OF CONTENT ➢ Executive Summary

➢ Acknowledgement ➢ Preface ➢ Introduction to Bearings ➢ Bearing industry  Global Scenario

 Indian Bearing Industry  Threats and limitation to Indian Market ➢ Organizational Profile  Introduction  Mile Stones  Company Profile  Research & Development  Quality Management System ➢ Bearing Manufacturing  Flow of Material in Bearing Industry  Classification of Bearing  Types & Features of Rolling Bearing  Bearing Designation in NBC ➢ Ball Bearing Manufacturing  Inner & Outer Ring Manufacturing  Spherical Ball Manufacturing  Cage Manufacturing  Rivet Manufacturing 3

Project report on training in National Bearing Company  Ball Bearing Assembly Line

➢ Roller Bearing Manufacturing  Inner

&

Outer

Manufacturing

for

Spherical,

Cylindrical & Tapered Roller Bearing  Roller Manufacturing  Cage Manufacturing  Roller Bearing Assembly ➢ Railway Bearing Manufacturing  Railway Bearing Assembly Line ➢ Heat Treatment  Heat Treatment Process  Hardening Procedure for High Carbon Steel  Hardening Procedure for Low Carbon Steel  Salt Bath Furnace

 Heat Treatment flow Chart ➢ Conclusion

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EXECUTIVE SUMMARY NBC Bearings Limited, a member company of C.K. BIRLA group of Companies - is a leading player in the Indian Bearing industry. The company manufactures a very wide range of bearings conforming to the stringent international quality standards. NBC manufacturing plants, located at Gunsi (Newai) Rajasthan, Manesar Haryana & Jaipur - was incorporated in the year 1946. Its feature the most advanced manufacturing technology. The company is certified to ISO/TS 16949, ISO 9001, and ISO 14001 standards. NBC India is a leading OEM supplier to the automotive industry, mechanical and electrical engineering industry, besides the Railways. Bearings produced at the EOU plant have gained ready acceptance and recognition of customers located in India & Indian Sub Continent, Europe & Africa. NBC’s main competitors in bearing are SKF, TIMKEN, NRB, FAG and other local brands.

OBJECTIVE: The main objective of this training is to learn different engineering processes and to develop skills and with that attitude I had done my engineering training with NBC Bearings Ltd. In this one month training period I had seen different work and key responsibility of various bearings department. Training was started with brief introduction program of NBC Bearing Ltd. and plant visit of different department. It was such a great experience to learn various engineering production methods used now a days & to better correlate the theoretical knowledge with practical observations and understandings.

ACKNOWLEDGEMENT 5


As the technologically advancement will enable us to get the environment we desire. The basic beatitude, bliss, euphoria & our endeavor to achieve complete and perfect knowledge in the field we choose that accompany the successful completion of any task would not be complete without the expression of appreciation of simple virtues to the people who made it possible. So, with reverence honor I acknowledge all those guidance and encouragement has made successful completion of training. I am thankful to Ms. Monika Joshi, H.R.D. Department, for her constant cooperation and able guidance & without her support this work would not have been so understandable. I am also thankful to Mr. R. Jaiswal, HOD Mechanical Department, G.V.S.E.T. who is always mentor to us. I am also very thankful to all respected persons who have directly or indirectly helped me in my earnest effort to accomplish this training.

Submitted By KETAN TOSHNIWAL

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PREFACE The Engineering curriculum is designed in such a way that student can grasp maximum knowledge and can get practical exposure to the corporate world in minimum possible time. Engineering schools of today realize the importance of practical knowledge over the theoretical base. The research report is necessary for the partial fulfillment of engineering curriculum and it provides an opportunity to the researcher in understanding the industry with special emphasis on the development of skills in analyzing and interpreting practical problems through the application of engineering theories and techniques. It is a new platform of learning through practical experience. It gives the learner an opportunity to relate the theory with the practice, to test the validity and applicability of his classroom learning against real life engineering situations.

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History & Evolution of Bearing An early type of linear bearing uses tree trunks laid down under sleds. This technology may date as far back as the construction of the Pyramids of Giza, though there is no definitive evidence. Modern linear bearings use a similar principle, sometimes with balls in place of rollers.

Tapered steering head bearings for a motorcycle

The first plain and rolling-element bearings were wood, but ceramic, sapphire, or glass were also used, and steel, bronze, other metals, ceramics, and plastic (e.g., nylon, polyoxymethylene, Teflon, and UHMWPE) are all common today. A "jeweled" pocket watch uses stones to reduce friction, and allow more precise time keeping. Even old materials can have good durability. As examples, wood bearings can still be seen today in old water mills where the water provides cooling and lubricatio

BEARING Definition - A

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.

BEARING FRICTION 8


Plain bearings are very widely used, and use surfaces in rubbing contact. Particularly with lubrication they often give entirely acceptable life and friction. On the other hand, low friction bearings are often important for efficiency, to reduce wear and to facilitate extended use at high speeds. Essentially, a bearing can reduce friction by virtue of its shape, by its material, or by introducing and containing a fluid between surfaces or by separating the surfaces with an electromagnetic field. By shape, gains advantage usually by using spheres or rollers, or by forming flexure bearings. By material exploits the nature of the bearing material used. (An example would be using plastics that have low surface friction.) By fluid exploits the low viscosity of a layer of fluid, such as a lubricant or as a pressurized medium to keep the two solid parts from touching, or by reducing the normal force between them. By fields exploits electromagnetic fields, such as magnetic fields, to keep solid parts from touching. Combinations of these can even be employed within the same bearing. An example of this is where the cage is made of plastic, and it separates the rollers/balls, which reduce friction by their shape and finish.

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Principles of Operation There are at least six common principles of operation: •

Sliding bearings, usually called "bushes", "bushings", "journal bearings", "sleeve bearings", "rifle bearings", or "plain bearings”.

•

Rolling-element bearings such as ball bearings and roller bearings.

• •

Jewel bearings, in which the load is carried by rolling the axle slightly off-center. Fluid bearings, in which the load is carried by a gas or liquid.

•

Magnetic bearings, in which the load is carried by a magnetic field.

•

Flexure bearings, in which the motion is supported by a load element which bends.

Motions Common motions permitted by bearings are: • • • •

Axial rotation e.g. shaft rotation Linear motion e.g. drawer Spherical rotation e.g. ball and socket joint Hinge motion e.g. door

Loads Bearings vary greatly over the size and directions of forces that they can support. Forces can be predominately radial, axial (thrust bearings) or moments perpendicular to the main axis.

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Global Scenario The world Market of quality Bearing is very vast. The Big player of bearing sector are present in U.S.A, Russia, Japan, China and eastern Europe. Some of leading bearing manufacturer are : -

- NSK Japan - NTN Japan - KOYA Seiko Japan - FAG Germany - SKF Sweden - NRB France - Timken USA

There are few of leading bearing manufacturer present in India. Most of the big player are having either technical or financial Collaboration with leading Auto Manufacturer. International Collaboration gives Access to best technology in the world.

Global Collaboration COMPANY

COLLABORATION

FAG Bearing India

FAG Germany

SKF India

SKF Sweden

NRB

Nadella, France

ABC Bearing Ltd.

NSK Japan

TIMKEN India

TIMKEN USA

BIMETAL Bearing Ltd.

Clevite Corporation USA

GABRIEL India

Suspension Italy

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Indian Bearing Industry The Indian Bearing Industry is estimated at Rs. 30 Billion approximately. The Industry has established a highly diversified 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 of 30% is Imported essentially for Industrial Application and special purpose. The Indian bearing Industry can be divided in to the organized sector and un-organized sector. The organized sector primarily caters to the Original Equipment Manufacturer (OEM) Segment, which predominantly comprises automotive railway and other Industrial users. The replacement market is dominated by unorganized Sector. ORGANISED SECTOR The organized Sector comprises about 12 big Manufacturer, who contribute to more than 50% of total turn over. Most of the big players are having either technical or financial with International Manufacturer. International Collaboration gives access to best technology in the world. SKF Bearing is the major player in the Indian market with the largest market share followed by National Engineering Industry (NBC) and FAG Bearing India the two other major players. UNORGANISED SECTOR The Unorganized Sector Include the Small Scale Manufacturer and Manufacturer of Spurious Bearing. The unorganized Sector Contribute to almost 15% of Total Industry turnover. The Unorganized Sector players have a strong regional presence and mainly cater to the needs of the replacement market. The direct employment provided by the above sectors is more than 12000 people. Indirect employment for Transportation, Tools, Containers, and Packaging etc. further helps in providing employment.

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INDUSTRY STRUCTURE

30% Domestic Organized Domestic Unorganized 55% 15%

Imports

USER SEGMENTS

Automobile

6% 21%

General Engineering

45%

Heavy Industries Including Railways

28%

6%

D IS T R IB U T IO N O F P R O D U C T IO N Electical Equipment & Others

7%

3% B a ll B e a rin g

M A R K E T D Y N A M IC S T a p e r R o lle r

C y lin d ric a l R o lle r

54% 30%

N e e d le R o lle r S p h e ric a l R o lle r

40% O E M M a rk e t R e p la c e m e n t M a rk e t 60% 13


Threats & Limitations to Indian Market  Increasing Competition in Domestic market.  Very Low Volume of Direct Export.  Weak Marketing Linkages.  Raw Material Bank is not present.  Low level of technology used by most of manufacturing Units.  Quality of Bearing Manufactured in the Small Scale Industry (SSI) Sector does not meet the International Quality Standard.  No Recent upgradation in Design, Technology, Process of Manufacturing and Quality Control.  Non existence of highly skilled Man Power.  Stiff Competition from China made Bearing.  Increase in Illegal Imports.  No Entry Barrier in the cluster  Increase in Raw Material Prices.  Government Rules & Regulations - According to estimate an entrepreneur need to interact with 14 Govt. departments to get permission for manufacturing & exporting. Most of their time is spend in filling up forms and submitting paper as per their requirement. Therefore Govt. rules and regulation have to be liberalized & the role of Govt. Department should be a facilitator rather than regulator.

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Introduction National Engineering Industries Ltd. is the largest manufacturer of Ball and Roller Bearings, Steel Balls and Axle Boxes complete with Roller bearing in India, which are being produced in factories at Jaipur and Newai. Bearings are manufactured for every possible application and requirement of modern engineering industry and we continue to develop new sizes, keeping pace with rapid advancement in the Indian engineering industry. NEI’s technical collaborations with the world’s leading conglomerates in the field of Bearing technology viz. M/s NTN Corporation of Japan, M/s BRENCO incorporated of USA have given a whole new dimension to the product range and a quality par excellence. NEI has already implemented modern concepts of Total Quality Management and accredited QS9000 and TS16949 certification, NEI has also been awarded Association of American Railroads (AAR) for AAR certificate M-1003 for Cartridge Tapered Roller Bearing in Feb 04-05. NEI has also been awarded ISO-14001 certificate for its concern and commitment towards a cleaner environment. NEI has successfully implemented SAP-ERP to re-engineer and integrate business processes to conform to world class standards.

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Milestones

Company Established as National Bearing Company (NBC) under Technical Collaboration with Hoffman, U.K. Ball Bearing Production Started

Railway Bearing Production Started Company Name changed to National Engineering Industries Ltd. (Retaining NBC as trademark). Tapered Roller Bearing Production Started under Collaboration with Federal Mogul Corporation, USA

Technical

Established Research & Development Division

Established Machine Building Division

Large Diameter Special Bearing Production Started Spherical Roller Bearing Production Started with Technical know-how from FAG-SRO Separate Factory for Ball Bearings at Gunsi Cartridge Tapered Roller Bearing Production Started in Technical Collaboration with BRENCO Incorporated, USA Largest Bearing with Outer Dia. 1300mm & Weight 4.39 Tons Produced

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Technical Collaboration with NTN Corporation of Japan for Ball, Cylindrical & Spherical Roller Bearing Modernization in Three Phases

ISO – 9001 Certificate Technical Collaboration with M/S Izumi Kogyo Co. Ltd., Japan for Machine Retrofitting/Remanufacturing & Overhauling Technical Collaboration with NTN Corporation, Japan for Tapered Roller Bearing & Hub Bearing IV-Phase Modernization Started

Implemented Ist Phase of SAP-ERP Solutions

QS-9000 & ISO-14001 Certification

Ts-16949 Certification

AAR Certification M-1003 for Cartridge Tapered Roller Bearing

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Company Profile National Engineering Industries Ltd., Jaipur was founded in the year 1946 as a pioneer industry in the field of bearing manufacture by the renowned industrialist, late Shri B.M. Birla, under the name of "National Bearing Company Limited." 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, and 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 "Indigenisation 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.

Mission of Company – “Keeping Nation on the Move”

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Project report on training in National Bearing Company 

PLANT AT JAIPUR i) Ball Bearing Precision Ball Bearings from 6 mm bore to 75 mm bore diameter are manufactured with in-process and post-process manufacturing facilities and centrally air conditioned assembly lines with auto gauging in grinding and testing equipments. The latest advanced techniques of manufacturing and Quality Assurance are implemented to meet the rapid increase in demand for Quality, diversity of specifications and new types of bearings. This Division is 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 Tapered Roller Bearings are manufactured in Inch and Metric series from 15.875mm bore to 95.25mm bore with technology obtained from Federal Mogul Corporation, USA and NTN Corporation, Japan. These bearings are used by all major Automobile manufacturers in the country as Original Equipment. This Division is spread over a covered area of 11,652 Sq. Meters.

iv)Railway Bearing (a) 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 by designing and developing Axle Boxes and bearings for fitment to Diesel Locomotive, wagon, the ICF broad and 19

Project report on training in National Bearing Company meter gauge coaches. Over a million NBC bearings and boxes are in service with the Indian Railways. The development of Axle Boxes and bearings for the high speed Rajdhani Locomotive, the Yugoslavian and Egyptian Railway wagons are the highlights of the completely indigenized design capabilities at NEI. On date more than 100 types of Axle Boxes & Bearings have been manufactured. (b)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.

(c) Cartridge Tapered Roller Bearing: For fitment to the new BOX-IN Updated Wagons designed by the RDSO, NEI is the only manufacturer in the country & largest manufacturer in the world. to indigenize these bearings to a high percentage. 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. This Division is spread over a covered area of 4,855 Sq. Meters.

i) Large Diameter Bearing 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 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 developed by NEI & grinding is done to close tolerances on CNC machines with electronic sizing and numerical display.

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Project report on training in National Bearing Company 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.

 PLANT AT GUNSI (NEWAI) 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.

 PLANT AT MANESAR NEI has set up its third Ball Bearing manufacturing plant in Manesar, the fastest growing industrial town of Haryana 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. The plant is spread over a covered area of 5200 Sq. Meters.

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Research & Development  Design & Development The design of all types of bearings is done on Pro-Engineer 3D Modeling & Analysis Software. Complete engineering and research with in-house facility for design development of all types of bearings and tooling with expert advice on design, development, manufacturing, installation and maintenance of bearings facility is available. 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. Machine Building has the capability and supports the Manufacturing Divisions by overhauling and retrofitting of the existing equipments, resulting in upgraded quality and improved productivity. R&D Division is spread over a covered area of 2,007 Sq. Meters.

 SAP – ERP In order to reengineer and integrate the Business processes for sales, production, materials and finance, NEI has successfully implemented SAP- ERP. By use of this Package, their processes now conform to international standard.

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Quality Management System  ISO / TS 16949:2002 NEI has been awarded TS 16949: 2002 on 17th October, 2003- THE MARK OF EXCELLENCE IN QUALITY MANAGEMENT SYSTEMS by BVQI for design, development, manufacture & supply of Ball Bearing, Tapered Roller Bearing and Cylindrical Roller Bearings. NEI Ltd. is the first bearing industry in India to have been recommended for TS 16949: 2002. This certificate is awarded only to suppliers of automobile manufacturers. TS 16949: 2002 quality management system is based on ISO 9001: 2000 in which many supplementary and additional requirements of automobile industries have been incorporated. Simplicity, effectiveness & efficiency of processes, error proofing and continuous improvement in processes thus become the highlight of TS quality management system.

 ISO 9001:2000 NEI’s Large dia. bearing division and railway bearing division which are manufacturing Cylindrical Roller Bearings, Spherical Roller Bearings, Cartridge Tapered Roller Bearings, Railway Rolling Stock and Spares has also been awarded to ISO 9001: 2000 on 9th October, 2003 by BVQI.

 ISO 14001:1996 NEI was awarded ISO -14001 certificates by BVQI in the month of March 2000 for Environmental Management System. NEI has done tremendous efforts in resource conservation, recycling and thick plantation. The efforts at NEI have saved precious natural resources like water, oil and power etc.

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Collaboration 

BRENCO Incorporated , U.S.A.

Since 1982-For Cartridge Tapered Roller Bearings for Railway wagons and locomotives. 

NTN Corporation , Japan

Since 1985-For Ball Bearings, Cylindrical & Spherical Roller Bearings. Since 1997-For Tapered Roller Bearings.



Izumi Kinzoku Kogyo Co. Ltd., Japan

Since 1996 - For re-manufacturing, retrofitting and overhauling of grinding and super finishing machines for bearing races.

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Flow of Material in Bering Industry Material from Outside Vendor such as Races (Inner & Outer), Cages, Retainers etc

 Store House for Size Inspection

 Laboratory For Metallurgical inspection based on the norms set by R & D Department

 No Yes

 Material is send back to vendor

 Material is send to specific departments for further Operations

 The following Operations are done: 1. Hardening Or Heat Treatment 2. Rough Grinding (Face, O.D., Inner & Track) 3. Finish Grinding (Face, O.D., Inner & Track) 4. Inspection 5. Assembly

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Classification of Bearing

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Types & Features of Rolling Bearing Name Single Row Radial Ball

Application 1.

In addition to Radial Loads, Axial Loads can be imposed in either direction.

2.

Highly Suitable for applications where High Speed & Low Power loss are required.

Bearing 1. Single Row Angular Contact Ball Bearing

They are capable of taking Radial Load & also the Axial Load in one direction.

2.

4 contact angles 15°, 25°, 30° & 40° are available. Higher the contact angle, higher is the Axial Load carrying capacity.

3. For Higher Speed lower contact angles are preferred. 1. Double Row Angular Contact Ball Bearing

back. 2.

They have only one inner and one outer ring.

3. 1.

They can take axial load in either direction. The Inner Ring has 2 Raceways & Outer Ring has a single Spherical

Self Aligning Ball Bearing

Cylindrical Roller Bearing

Tapered Roller Bearing

Raceway with its centre of curvature coincident with bearing axis. 2.

This has an advantage of correcting minor angular misalignment of Shaft

1.

and Housing caused by Machining or Mounting Error. They have High Radial Load capacity and are suitable for High Speed.

2.

Double Row bearing have high Radial Rigidity and are used primarily for

1.

high Precision Instruments. They are capable of taking high Radial Loads & also Axial Load in one Direction.

2. Depending upon the contact angle they are divided into 3 types, Normal, 1.

Spherical Roller Bearing

Thrust Bearing

They are 2 single Row Angular Contact Ball Bearing mounted back to

Medium & Steep Angle. Due to coincide of the centre of curvature of the outer ring raceway surface with the bearing axis, they are also called as Self Aligning Bearing.

2.

They can take Heavy Radial Load & some Axial Load in either direction.

3. 1.

They are suitable for the use where there are Heavy or Impact Load. They are capable of taking High Axial Load and some amount of Radial Load.

2.

Outer & Inner Rings are called as Washer because they seems to be as Washer in Structure.

Bearing Designation In NBC Rolling bearing part numbers indicate Bearing type, Dimensions, Tolerance, Internal Construction & other related specifications. 28


The Digits & Indications are:➢ 1st Digit – Bearing Type ➢ 2nd Digit – Width or Height Series ➢ 3rd Digit – Diamete Series ➢ Last 2 Digits – Bore Diameter

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Inner & Outer Ring Manufacturing Flow Chart Forged Ring ( De-Scaled) as Raw Material (SAE 52100 Steel) Turning Operation

 Heat Treatment

 Hardness Testing

 Rough Grinding (Face, Outer Diameter, Bore or Track)

 Finish Grinding (Face, Outer Diameter, Bore or Track)

 Honing & Super Finishing

 Washing

 Application of Rust Preventive

 Ready for Dispatch to Assembly

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Theory Ball Bearings are generally made of High Carbon Steels, such as AISI 52100 because the life of the bearing steel is determined by the purity of cleanliness of steel. The 52100 steel are subjected to a rigorous purification process with stringent controls in order to meet the ever-increasing standard of cleanliness & eliminating non-metallic inclusions & impurities. The impurities are removed through various processes such as vacuum degassing & consumable electrode vacuum melting (CEVM). The Chemical composition of the SAE 52100: Element

C

Si

Mn

S

P

Cr

Minimum Maximum

0.98 1.10

0.15 0.35

0.25 0.45

---0.025

---0.025

1.30 1.60

Oxygen Content – Not more than 15 ppm The Turning operations are divided into various lathe Operations viz. O.D., face, track & Bore. All these operations are done on production lathe machines. The Hardening of steel is achieved by heat treatment process in which the steel microstructure is manipulated by cycles of heating & quick cooling to obtain the optimum hardness range for steel – usually on the order of 60 to 64 on Rockwell C Hardness Scale. When slowly quenched it would form Austenite & Pearlite which is a partly hard and partly soft structure respectively. Hardening of steel requires a change in structure from Body Centered Cubic Structure found at room temperature to Face Centered Cubic Structure found in Austenite Region. When Steel is suddenly Quenched Martensite is formed which is extremely strong and If steel is Quenched slowly then Pearlite is formed which is extremely Soft.

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Project report on training in National Bearing Company The Next stage is grinding, in order to give the rings the right form and dimension. The operations occur in following Order:  Face Grinding – It is the first operation for both inner & outer rings. Both faces are ground simultaneously to give the final width.  Outside / Center less Grinding – Outside diameter of inner ring is ground to final dimension in center less grinding machine.  The final machining operations are carried out on parallel lines of grinding and finishing machines. Inner Rings have the bores & raceways ground while Outer Rings have the only the raceway ground. These operations are carried away by form dressed grinding wheels. After grinding Operation, Honing is done. After Honing the rings are thoroughly washed with water based cleaning medium so Rings get perfectly cleaned before Assembly is done.

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Spherical Ball Manufacturing Flow Chart Input Wire Rod as Raw Material (SAE 52100 Steel)

 Shearing & Handling Operation On Ball Header Machine

 Deburring on Vibro Benz Machine

 Lushing of excess material after the Ball forged in Cold Header

 Heat Treatment of Ball

 Grinding of Ball in Rotary Grinding Machine (Flashing Machine)

 Lapping in Ball Lapping Machine

 Inspection for checking Hairline Cracks

 Lapping of Balls in Tumbling Barrel

 Magnetic Crack Testing

 Washing


 Packing & Dispatch to Assembly Line

Theory

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Project report on training in National Bearing Company The Raw Material used (SAE 52100) for manufacturing of balls is a specially formulated grade of Steel Wire. The Material is Supplies either by wire or rod. It is then cut to length & width. The wire or rod is then fed through a header. This cold forged process produce “slugs” at an incredibly high speed. Wire is fed from decoilers into cold heading machines where it is cut into blanks and then pressed into balls between hemispherical dies. The flash around the balls produced during pressing is removed by filing plates in deburring machines. These rough shaped balls have a ring around the middle. The next process is to remove this ring by machining in rill-filing machine, equipped with one fixed and one rotating cast iron rill-plate. Concentric grooves in the plate ensure that the whole ball surface is machined to same extent and thus a spherical form is achieved Final inspection for size, form and surface finish is carried out on a sample basis by means of high resolution microscopes and other precision equipment because a tiniest deviation even of the order of 1 Å (10-10 m) in the roundness of bearing element can have an impact on bearing quality. The balls are then cleaned and packed ready for bearing assembly operation

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Cage Manufacturing Flow Chart Raw Material (Narrow width Cold Rolled Sheet IS 4397)

 Blanking & Punching

 Forming (Pocketing)

 Inspection & Batch Checking

 Shot Blasting/Vibro

 Assembly Line

Theory The cages for various bearing sizes are manufacture from Cold Rolled (C.R.) & Cold Annealed narrow width sheets IS 4397. The C.R. sheet is converted in the cage in Press Machine in Successive Operations: Blanking, Punching, Forming (Pocketing) rivet holes and visual inspection is carried for any deformity.

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Rivet Manufacturing Flow Chart Raw Material (Wire EN 8 or EN 9)

 Heading in Ball Header

 Deburring in Vibro Benz Machine

 Rust Preventive Oiling

 Assembly Line

Theory The Rivets are manufactured from wire rods. The Wires are cut in requires sizes in Rivet Header machine, then in Vibro Machine it is Super – Finished. There is no Grinding operation involved.

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Ball Bearing Assembly Line Flow Chart Cage

Rivet

Outer

Inner

Ball

Put Inner in Outer

 Insert Balls

 Put Retainers

 Put under Riveting Machine

 Riveting

 Washing

 De-Magnetizing

 Inner & Outer Diameter Inspection Machine

 Radial Clearance Testing Machine

 Washing

 Double side Vibration (Noise) Testing Machine

 Laser Aching Machine

 Application of Anti Rust

 Packaging of Bearing in Pillow Wrapping Machine & Ready to Dispatch

Theory

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Project report on training in National Bearing Company Finally the rings, balls & Cage which have been manufactured in different locations come together for semi – Automatic or Automatic Assembly. Raceways & Rings are Optically Inspected separately prior to assembly. By selecting suitable combinations of ring & ball sizes the required internal clearance is obtained. Balls are fed between the rings and spaced equally before the two cage halves are fitted and riveted together. After washing, the final inspection sequence starts which consist of number of checks such as running accuracy, vibration level, outside and bore diameters and radial clearance of bearings. The bearings are then automatically washed, coated with preservative, greased and fitted with seals or shields before being packed.

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40


Inner & Outer Ring Manufacturing for Spherical, Cylindrical & Tapered Roller Bearing Flow Chart Forged Ring (De-Scaled) as Raw Material (SUJ 2 Steel or SC/SCM/SNCM Steel) Turning Operation

 Heat Treatment

 Hardness Testing

 Rough Grinding (Face, Outer Diameter, Bore or Track)

 Finish Grinding (Face, Outer Diameter, Bore or Track)

 Honing & Super Finishing

 Washing


 Ready for Dispatch to Assembly

41


Theory The contact surfaces of the bearing rings and rolling elements are subjected to repeated heavy stresses, so they must maintain high precision and rotational accuracy. To accomplish this, the rings and rolling elements must be made of a material that has high hardness, resistant to rolling fatigue, wear resistant and has good dimensional stability. High carbon chromium bearing steel (SUJ 2) deep hardened by the hardening method & case hardening steel (SC/SCM/SNCM) with a hardened carburized outer layer are used for the rings and rolling elements of standard bearings. The most widely used and most suitable materials for rolling bearings are high carbon steels. The most commonly used of these steels is SUJ2. For bearings with large cross section dimensions SUJ3 or SUJ5 having good hardening properties are used. NBC uses high carbon steel for almost all of spherical roller & cylindrical roller bearings. For case hardening steel; Chrome Steel (SCr), Chrome Molybdenum Steel (SCM) and Nickel Chrome Molybdenum Steel (SNCM) are used because of its combination of a hard surface layer which has been carburized and hardened to an appropriate depth, and a relatively pliable inner core, case hardening steel has excellent efficiency against shock load. NBC uses case hardening steel for almost all of tapered roller bearings. Since the life of the bearing steel is determined by the purity of cleanliness of steel the above grade steels are low in non-metallic impurities & low in oxygen content because they are refined by a vacuum degassing process & outside hearth smelting process. The Chemical compositions of above steels are:

Specification

Elements

C

Si

Mn 42

P

S

Ni

Cr

Mo


SUJ 2

SUJ 3 / SUJ 5

SCr 420

SCM 420

SCNM 420 / SCNM 815

Minimum

0.95

0.15

----

Maximum

1.10

0.35

0.50

Minimum

0.95

0.40

0.90

Maximum

1.10

0.70

1.15

Minimum

0.18

0.15

0.60

Maximum

0.23

0.35

0.85

Minimum

0.18

0.15

0.60

Maximum

0.23

0.35

0.85

Minimum

0.15

0.15

0.35

Maximum

0.21

0.35

0.65

---0.02 5 ---0.02 5 ---0.03 0 ---0.03 0 ---0.03 0

---0.025 ---0.025 ---0.030 ---0.030 ---0.030

-------

1.30

----

1.60

----

-------

0.90

0.10

1.20

0.25

-------

0.90

----

1.20

----

-------

0.90

0.15

1.20

0.30

0.50

0.15

0.90

0.30

2.0 0 4.0 0

The Turning operations are divided into various lathe Operations viz. O.D., face, track & Bore. All these operations are done on production lathe machines. The Hardening of steel is achieved by heat treatment process in which the steel microstructure is manipulated by cycles of heating & quick cooling to obtain the optimum hardness range for steel – usually on the order of 60 to 64 on Rockwell C Hardness Scale. When slowly quenched it would form Austenite & Pearlite which is a partly hard and partly soft structure respectively. Hardening of steel requires a change in structure from Body Centered Cubic Structure found at room temperature to Face Centered Cubic Structure found in Austenite Region. When Steel is suddenly Quenched Martensite is formed which is extremely strong and If steel is Quenched slowly then Pearlite is formed which is extremely Soft.

43


The Next stage is grinding, in order to give the rings the right form and dimension. The operations occur in following Order:  Face Grinding – It is the first operation for both inner & outer rings. Both faces are ground simultaneously to give the final width.  Outside / Center less Grinding – Outside diameter of inner ring is ground to final dimension in center less grinding machine.  The final machining operations are carried out on parallel lines of grinding and finishing machines. Inner Rings have the bores & raceways ground while Outer Rings have the only the raceway ground. These operations are carried away by form dressed grinding wheels. After grinding Operation, Honing is done. After Honing the rings are thoroughly washed with water based cleaning medium so Rings get perfectly cleaned before Assembly is done.

44


Roller Manufacturing Flow Chart Input Bar as Raw Material (SUJ 2 Steel)

 Turning Operation on Production Lathe

 Deburring

 Lushing of excess material

 Rough Grinding of Rollers

 Heat Treatment of Rollers

 Finish Grinding of Rollers

 Lapping in Roller Lapping Machine

 Inspection for checking Hairline Cracks

 Lapping of Rollers in Tumbling Barrel

 Magnetic Crack Testing

 Washing


 Dispatch to Assembly Line

Theory 45


The Raw Material used (SUJ 2 Steel) for manufacturing of rollers is a specially formulated grade of Steel. The Material is Supplies by rod. It is then cut to length & width on Production Lathe. For Spherical Rollers or Tapered Rollers, The rod is then fed through a header. This cold forged process produce “slugs” at an incredibly high speed. Rod is fed from decoilers into cold heading machines where it is cut into blanks and then pressed between hemispherical dies or conical dies. For Cylindrical Rollers the above procedure is not done. The flash around the rollers produced during pressing is removed by filing plates in deburring machines. These rough shaped spherical rollers have a ring around the middle. The next process is to remove this ring by machining in rill-filing machine, equipped with one fixed and one rotating cast iron rill-plate. Concentric grooves in the plate ensure that the whole roller surface is machined to same extent and thus a spherical form is achieved The next process for Rollers is grinding in which rollers are grind in the order: Face, O.D, and I.D. The grinding process is done in two phases; one prior to Heat Treatment (Rough Grinding) & one after the heat treatment process (Finish Grinding). Final inspection for size, form and surface finish is carried out on a sample basis by means of high resolution microscopes and other precision equipment because a tiniest deviation even of the order of 1 Å (10-10 m) in the roundness of bearing element can have an impact on bearing quality. The rollers are then cleaned and dispatched for bearing assembly operation

Cage Manufacturing 46


Flow Chart Raw Material (Narrow width Cold Rolled Sheet IS 4397)

 Blanking & Punching

 Forming (Pocketing)

 Inspection & Batch Checking

 Shot Blasting/Vibro

 Assembly Line

Theory The cages for various bearing sizes are manufacture from Cold Rolled (C.R.) & Cold Annealed narrow width sheets IS 4397. The C.R. sheet is converted in the cage in Press Machine in Successive Operations: Blanking, Punching, Forming (Pocketing) rivet holes and visual inspection is carried for any deformity.

47


Roller Bearing Assembly Line Flow Chart Cage

Outer

Inner

Rollers

Put Inner in Outer

 Insert Rollers & Cage

 Put under Pressing Machine

 Pressing

 Washing

 De-Magnetizing



 Washing




 Packaging of Bearing in Pillow Wrapping Machine & Ready to Dispatch

Theory 48


Finally the rings, Rollers & Cage which have been manufactured in different locations come together for semi – Automatic or Automatic Assembly. Raceways & Rings are Optically Inspected separately prior to assembly. By selecting suitable combinations of ring & Rollers sizes the required internal clearance is obtained. Rollers are fed into the cage which are together fed in between the Outer & Inner Raceway & are fitted together through pressing. After washing, the final inspection sequence starts which consist of number of checks such as running accuracy, vibration level, outside and bore diameters and radial clearance of bearings. The bearings are then automatically washed, coated with preservative, greased and fitted with seals or shields before being packed.

49


Railway Bearing Assembly Line Flow Chart

Put Spacer Ring in Outer

 Insert Cage & Rollers Assembly

 Washing

 Insert Seal Ring or Seal Caps

 Put End Caps

 De-Magnetizing



 Washing




 Packaging of Bearing in Pillow Wrapping Machine & Ready to Dispatch Assembly with Sealing Rings

Assembly with Lamellar Rings

50


Theory Finally the Outer rings, Spacer Rings & Rollers & Cage Assembly which have been manufactured in different locations come together for semi – Automatic or Automatic Assembly. Raceways & Rings are Optically Inspected separately prior to assembly. By selecting suitable combinations of Outer & Inner rings, the required internal clearance is obtained. Spacer Ring is inserted between the Rollers & Cage Assembly to avoid interaction between them. After washing, the final inspection sequence starts which consist of number of checks such as running accuracy, vibration level, outside and bore diameters and radial clearance of bearings. The bearings are then automatically washed, coated with preservative, greased before being packed. Cylindrical roller bearings are used on wagons, BEML coaches and engines. Spherical roller bearings are used on ICF coaches, some wagons and engines. Tapered roller bearings are only used on engines.

51


Heat Treatment Process

Chugai – Ro Heat Treatment Furnance Hardening Procedure for High Carbon Steel ( C – 0.9% to 1.10%)

Process

Hardening

Procedure

Heat the Furnace 850-870O C

Quenching Fast cooling 600 C – Oil Quenching 1800C – Salt Bath

Hardness

------

62 – 66 HRC

Time

35-60 min. According to the job

5-15 min.

Tempering Furnace Heating 1650-1800C

60 – 64 HRC 150 min.

Air Cooling Cool at Room Temperatu re -----------

Hardening Procedure for LC Steel (Low Carbon Steel) 52


Process

Procedure

Hardness Time

Carburizing Carbon Furnace heating at 9400 C - 9500 C .200 - .250 8 – 10 hours

Hardening

Quenching

Temperin g

Furnace temperature at 8500 C – 8700 C

Fast cooling 600 C –for oil quenching only

Heat the Furnace at 1650 C1800 C

60 – 64 HRC

52 – 62 HRC

-----35-60 min. According to the job.

Salt Bath Furnace

Heat Treatment 53

5-15 min.

120-180 min.


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)

54


Conclusion This report describes the NBC bearing industry and its technology. 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. 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 . It has been long pursued policy and commitment of National Engineering Industries Limited (NEI) to adhere to highest standards of integrity – professional and financial – and business ethics in the operation of its business. We believe that this organization has been handed to us by the various stakeholders in "trust” and we as professional managers are the "trustees" of those stakeholders. It is therefore our responsibility to ensure that the organization is managed in a manner that protects and furthers the interests of our stakeholders.

55

Training Report of NBC Bearing

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