Anti-Friction Bearings in Mechanical Systems

ANTI- FRICTION BEARINGS Part I Lec. Lec.11 11 Dr. Ameer Ali Kamel Prod.Eng.& Mech. Design Dept. Faculty of Engineering

1. INTRODUCTION - 1. INTRODUCTION Anti friction bearings are mechanical elements that are used to transfer external loads from the rotated mechanical members (e.g. shafts and axes) to fundament. This type of elements can be classified into two main groups, which are: 1.Radial bearings. 2.Thrust bearings. 2

A. RADIAL BEARING 1 : Inner Race 2 : Outer Race 3 : Rolling Elements 4 : Cage 5 : Shaft 6 : Casing 2 1 3 4 D B Design16- Manufacturing of Ball Bearing 3

B. THRUST BEARING 1 : Inner Race 2 : Outer Race 3 : Rolling Elements d2 4 : Cage 5 : Shaft D 6 : Casing 4

2. ROLLING ELEMENTS TYPES - The anti friction bearing can be obtained in different forms that can carry different amount of loads. - The rolling elements can be found in the form of: Balls Rollers (cylinders) Needles Spherical rollers Taper roller. Design17-A Minst13- Bearings - How it's made. 5

3. TYPES OF RADIAL BEARINGS The various types of radial bearings are mainly: 1. Ball bearing. 2. Roller bearing. 3. Conical bearing. 4. Concave bearing B D d Also, bearings can be: 1. Single row Bearing 2. Double row bearing Design18- bearing radial and thrust load simulation 6

Ball bearing can be: a. Deep groove ball bearing. b. Angular contact ball bearing. c. Double row deep groove ball bearing. d. Double row Self-alignment ball bearing. B D d 7

The bearing manufacturers supply the market with different bearing configurations. Ball bearings with metallic shield Ball Bearing with synthetic rubber seals Felt sealed bearing extremely dirty conditions). (good protection in (a) (b) (c) Design19- ZZ 608 Bearing assembly 8

4. LOADING OF BEARINGS In general, radial bearings are designed to carry out radial load while thrust bearings are needed for supporting axial load. However, radial bearing can carry out additional axial part of axial load. Radial bearings Radial load + Axial Load Axial Load ONLY Thrust bearings Design43- Bearing simulation 9

Single Row Double Row Single Row Double Row Shaft Shaft Shaft Shaft Deep Groove Self-Alignment Axial & Self Alignment Thrust Bearing Angular Contact 10

Angular contact Deep Groove AXIAL Self-Alignment 11

For Example: The single row deep groove ball bearing can resist an axial load of 70% of its capacity of radial load. B R D A d Fr 1 Fa 0.7 Deep Groove Design20- Bearing kataloge 12

For Example: The single row self alignment ball bearing carries only 20% axial load. R A Fr 1 Fa 0.2 Self Alignment Fig. 4 Axial and Thrust load carrying capacity of different bearing types. Design21- bearing thrust load simulation 13

Also, it is clear that single and double row thrust bearing carries only thrust loads and they have not ability to carry out axial load. Fr Fa 1 Fr Fa 1 A A Non Non Double Row Thrust Single Row Thrust Design22- Two raw thrust bearing 14

Radial Axial Radial Axial 1.0 0.7 1.7 None 1.0 0.2 1.7 None 1.4 0.7 1.7 V.Low 2.3 0.7 2.0 0.2 None 1.0 Light None None 1.0 1.9 0.7 15

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