Classification of Bearings

Ball Bearing, Journal Bearing

1. MEA ENGINEERING COLLEGE PERINTHALMANNA NASEEL IBNU AZEEZ.M.P Assistant Professor Department of Mechanical Engineering Email:[email protected]

2. Bearings Bearing is a machine component which supports another machine element (known as journal). It permits relative motion between the contact surfaces of the members, while carrying the load

3. Classification of Bearings Based on the Direction of Load Radial Bearing Load acting perpendicular to the direction of motion of moving element Thrust Bearing Load acts along the axis of rotation

4. Based on Nature of Contact Sliding Contact Bearing Sliding takes place between the fixed and moving element of bearing and its also known as plain bearing

5. Rolling Contact Bearings Balls or rollers introduced between moving and fixed elements and it is also known as anti-friction bearings

6. Sliding Contact Bearing/Journal Bearing Types of Journal Bearings

7. Types of Journal Bearings Based on Lubrication Journal Bearing Hydrodynamic Bearing Hydrostatic Bearing

8. Hydrodynamic Bearing It is a lubricated journal bearing that uses fluid, liquid or gas lubricants to separate the moving surfaces completely without an external pressure supply, required pressure to support journal inside the bearing is generated from wedging action inside the journal

9. 9 Journal (Sleeve) Bearings Load is transferred through a lubricant in sliding contact

10. 10 Journal (Sleeve) Bearings Thick-film lubrication (hydrodynamic), pressure distribution, and film thickness. h min = minimum film thickness, c = radial clearance, e = eccentricity

11. Hydrostatic Bearings It is also known as externally pressurized lubrication in which the pressurized lubricant pumped into clearance of bearing and journal hence it can support higher loads even at stationary conditions with very low starting friction resulting very low tear an wear. But they are very expensive

12. Rolling Contact Bearings 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

13. Rolling Contact Bearings 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

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

15. Roller contact bearing With its parts Outer ring (or) Outer race Inner ring (or) inner race Rolling elements Cage or retaining ring Construction Diagram :

16. Classification of rolling bearings 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 Classified into two types

17. 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

18. 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.

19. Angular contact Ball 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

20. RADIAL AND ANGULAR BEARING

21. Standardization of bearings

22. 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.

23. ROLLER BEARINGS