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SUMMER TRAININGJaipur institute of Engineering& technology(Affiliated to Rajasthan Technical University,kota) Academic session 2011-2015Submitted By: RAJESH KUMAR Submitted To:- Mr. Sulabh Nalwaya

NATIONAL ENGINEERING INDUSTRIES LTD.,JAIPUR

Introduction Of The Company

NBC Bearingsis the premier brand of Indias leading bearingsmanufacturer and exporter company, founded in 1946 by the greatindustrialist lateShri B.M.Birla.NBC is a pioneer, renowned for excellence in quality and delivery for over60 years.NBC produces over 100 million bearings each year in more than 1000sizes to serve ahost of varied customers across India and 21 othercountries in 5 continents.It has the capacity todevelop bearings from 10 mm bore to 2000mmouter diameter. The product range includes ball bearings, tapered rollerbearings, double row angular contact (DRAC) bearings, cylindrical andspherical roller bearings.With increasing activities and grant of industrial licenses forother vitalindustries and manufacturing, the name of the company was changed in1958 to National Engineering Industries Ltd. retaining its originaltrademark NBC.

1BearingsFunction:Carry load in one or several directions while allowing frictionless motion in other directions

Fatigue = F(Pressure, Velocity)

3 main types of BearingsRolling Element BearingsSliding BearingsElastomeric Bearings12 .TYPES OF ROLLING BEARINGSI. Ball Bearings

II. Roller Bearings

Ken Youssefi
Mechanical Engineering Dept.
*
Rolling Contact Bearings
Deep groove (Conrad) bearingFilling notch ball bearing or maximum capacity bearingAngular contact bearings (AC)
Ball bearings
Thrust bearingsLinear bearings

Mechanical Engineering Dept.

Ken Youssefi
Mechanical Engineering Dept.
*
Ball Bearings
Filling notch or maximum capacity ball bearings
Bearings have the same basic radial construction as Conrad type. However, a filling notch (loading groove) permits more balls to be used.
Thrust load capacity drops to 20% (2 directions) of radial load capacity.
Notch
Radial load capacity is 20 40% higher than Conrad type

Mechanical Engineering Dept.

Ken Youssefi
Mechanical Engineering Dept.
*
Ball Bearings
Filling notch or maximum capacity ball bearings
Bearings have the same basic radial construction as Conrad type. However, a filling notch (loading groove) permits more balls to be used.
Thrust load capacity drops to 20% (2 directions) of radial load capacity.
Notch
Radial load capacity is 20 40% higher than Conrad type

Mechanical Engineering Dept.

Ken Youssefi
Mechanical Engineering Dept.
*
Ball Bearings
Angular contact bearings (AC)
The centerline of contact between the balls and the raceway is at an angle to the plane perpendicular to the axis of rotation.
Used for high radial and thrust load applications
Extra support in the back
Direction of thrust

Mechanical Engineering Dept.

Ball Bearings
Filling Notch
Angular Contact
Self aligning
Thrust

1. Turning operation2. Center less grinding3. Heat treament4. Hardness testing5. Rough grinding6. Finish grinding washing7. Assembly Operation8. Lapping Operation9. Packing Operation10. Distributer

Inner/Outer Ring Manufacturing Process STEPS OF HEAT TREATMENT

1. HARDENNING TEST

2. OVALITYCHECKING

Ovalitycheckingis done to long diameter and thin width outer race of bearing. Ovalitycheckingis done automatically by ovalitycheckingmachine. This machine checks the ovality of outer race and then put correct one to one side , wrong one to other side. Now these outer race of bearing which are found oval in shape again taken to dial gauge forcheckingthe ovality reading. After this nails are put in between the outer race. And again these outer races are put into different furnace. After sometime all outer races are taken out and get cool. This is how the ovality of outer race of bearing is removed.

HEAT TREAMENT

Heat treatment is the process of heating and cooling metals to achieve desired physical and mechanical properties through modification of their crystalline structure. The temperature, length of time, and rate of cooling after heat treatment will all impact properties dramatically. The most common reasons to heat treat include increasing strength or hardness, increasing toughness, improving ductility and maximizing corrosion resistance.Common heat treatments:AnnealingQuench HardeningPrecipitation hardeningTempering

Grinding operation

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. 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 withgrinding 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 a 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.

Assembly process ASSEMBLY SECTION

Cage Rivet Outer Ring Inner ring BallsPut Inner In Outer|Insert cage|Insert Balls|Put under Riveting Machine|Riveting|Washing Of Bearing|Packing of bearing|Ready to Dispatch

What Is Lapping?

Lappingis amachineoperation, in which two surfaces are rubbed together with anabrasivebetween them, by hand movement or by way of a machine.

Packing operation

Distribution for different placeThanks&anyinquery