Rolling contact bearing

1. A
Seminar On
“Rolling Contact Bearings ”
Presented By
Amol Dhangar (TEMA117)
Rohan Ghadage (TEMA118)
Rushikesh Honkhambe (TEMA119)
Dipak Jadhav (TEMA120)
Lalit Jadhav (TEMA121)
Jalal Hatim (TEMA122)
Under the guidance of
Prof. S.N Khetre
Department Of Mechanical Engineering
NUTAN MAHARASHTRA INSTITUTE OF ENGINEERING AND TECHNOLOGY
TALEGAON , PUNE-410506 (INDIA)
[2017-2018]
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2. Contents
1) Introduction
2) Types of bearings
3) Construction of bearing
4) Classification
5) Advantages
6) Disadvantages
7) Applications
8) Conclusion
9) Referances
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3. Introduction to bearings
•Objective of bearing is to providerelative positioning and rotational
freedom while transmitting a load between two parts.
•In rolling contact bearings as the name implies the friction is of rolling
type.
•It is much smaller than the sliding type
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4. Types of bearings
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•Rolling Contact Bearings
load is transferred through rolling elements such as balls, straight
and tapered cylinders and spherical rollers.
•Journal (sleeve) Bearings
load is transferred through a thin film of lubricant
(oil).

5. Rolling Contact Bearings
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•Rolling contact bearings are also known as antifriction
bearings.
•The load, speed, and operating viscosity of the lubricant affect the friction
characteristics of a rolling bearing.
•These bearings provide coefficients of friction between
0.001 and 0.002.
•The designer must deal with such matters as fatigue, friction, heat, lubrication,
kinematics problems, material properties, machining tolerances, assembly, use and cost

6. Construction of bearing
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The rolling contact bearings are composed of four elements.
•Outer race
•Inner race
•Rolling element
•Cage of retaining ring

7. Construction Diagram
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Roller contact bearing With its
parts
i.Outer ring (or) Outer race
ii.Inner ring (or) inner race
iii.Rolling elements iv.Cage or
retaining ring

8. Classification of rolling bearings
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Classified into two types
i.Ball Bearing
•Deep groove (Conrad) bearing
•Filling notch ball bearing
•Angular contact bearings (AC)
ii. Roller Bearing
• Cylindrical bearings
• Needle bearings
• Tapered bearings
• Spherical bearings

9. 09
Ball Bearings
Deep groove bearing
•Single row of deep groove ball bearing can combinational of radial and
thrust load.
•Load capacity is limited by the number of balls
•Primarily designed to support radial loads, the thrust capacity is about 70%
of radial load capacity

10. 10
Filling notch ball bearings
•Bearings have the same basic radial construction as Conrad type. However, a filling
notch (loading groove) permits more balls to be used.
•Radial load capacity is 20 – 40% higher than Conrad type.
•Thrust load capacity drops to 20% (2 directions) of radial load capacity.

11. Angular contact Ball bearings (AC)
•Thecenterline of contact between the balls and the raceway is at an angle to the plane
perpendicular to the axis of rotation.
•Usedfor high radial and thrust load applications
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12. Roller Bearings
• Roller bearings have higher load capacity than ball bearings, load is
transmitted through line contact instead of point contact.
• Helical rollers are made by winding rectangular material into roller. Due
to inherent flexibility they are capable of taking considerable misalignment.
• A roller with length much larger than diameter is known as needle roller
and are used where radial space is limited. Cage nay be absent in needle roller
bearings.
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13. 13
ROLLER BEARINGS

14. Bearing life
•Life number of revolution or hours of operation, at constant speed, required for the
failure criterion to develop
•defines the number of revolution or hours of operation, at constant speed, in such a way
that of the bearings tested (from the same group) will complete or exceed before the first
evidence of failure develops. This is known as life.
For ball bearings and spherical bearings:
L10 = 500 (hours) x 33.33 (rpm) x 60 = 106 = 1 million revolutions
For tapered bearings manufactured by Timken:
L10 = 3000 (hours) x 500 (rpm) x 60 = 90 x 106 = 90 million revolutions
Basic Dynamic Load Rating, C constant radial load that a group
of bearings can carry for L10 life.
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15. Bearing Life
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16. Merits of rolling element bearings
•Low starting and good operating friction torque
•Requiring less axial space
•Good low-temperature starting.
•Rapid replacement
•Good low-temperature starting.
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17. Demerits of rolling element bearings
•Greater diametric space.
•More severe alignment requirements.
•Noisier normal operation.
•Finite life due to eventual failure by fatigue.
•Poor damping ability
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18. Conclusion
• Studied General information about Helical gear and its terminologies.
•Advantages over the spur gear and disadvantages.
• Composition, microstructure , hardness & case depth found satisfactory.
• Fractographic features indicated that fatigue was the main failure cause .]
• Misalignment was observed which has caused failure.
• Formation of destructive pitting and spalling at one end was due to load
concentration at that area.
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19. REFERANCES
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1) Bhandari, V. B. Machine Design data book, Tata McGraw Hill
Publication Co. Ltd.
2) A Textbook of Machine Design By R. S. Khurmi &
J. K. Gupta
3) Technical Publications: Design of Machine Elements 2.

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