Bearings

1. Bearing is amachine component which supports another machine element (known as
journal).
It permits relative motion between the contact surfacesof the members, while
carrying theload

2. • Basedon the Direction of Load
1. Radial Bearing
Load acting perpendicular to the direction of motion of
moving element
2. Thrust Bearing
Load acts along the axis of rotation

3. • Basedon Nature ofContact
1. Sliding ContactBearing
Sliding takes place between the fixed and moving element of
bearing and its also known asplain bearing

4. 2. Rolling ContactBearings
Balls or rollers introduced between moving and fixed elements
and it is also known asanti-friction bearings

6. Journal Bearing
Hydrodynamic Bearing Hydrostatic Bearing

8. 9
Journal (Sleeve) Bearings
Load is transferred through a lubricant in sliding contact

9. 10
Journal (Sleeve)Bearings
Thick-film lubrication (hydrodynamic), pressure distribution, and
film thickness.
hmin = minimum film thickness, c = radial clearance,
e = eccentricity

11. Rolling ContactBearings
Rolling contact bearings are also known asantifriction bearings.
The load, speed, and operating viscosity of the lubricant affect the friction
characteristics of arollingbearing.
Thesebearings provide coefficients of friction between 0.001and 0.002.
The designer must deal with such matters as fatigue, friction, heat, lubrication,
kinematics problems, material properties, machining tolerances, assembly, use and
cost

12. Rolling ContactBearings
Rolling contact bearings are also known asantifriction bearings.
The load, speed, and operating viscosity of the lubricant affect
the friction characteristics of arolling 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, useandcost

13. Constructionofbearing
The rolling contact bearings are composed of four
elements.
i. Outer race
ii. Inner race
iii. Rolling element
iv. Cageof retainingring

14. Rollercontactbearing
With itsparts
i. Outer ring (or)Outer race
ii. Inner ring (or)inner race
iii. Rolling elements
iv. Cage orretainingring
Construction Diagram :

15. Classification of rolling bearings
Classified into two types
i. Ball Bearing
• Deep groove (Conrad)bearing
• Filling notch ball bearing
• Angular contactbearings (AC)
ii.Roller Bearing
• Cylindricalbearings
• Needle bearings
• Taperedbearings
• Sphericalbearings

16. Ball Bearings
Deep groovebearing
Single row of deep groove ball bearing cancombinational of radial and
thrust load.
Loadcapacityis limited by the number of balls
Primarilydesigned to support radial loads,the thrust capacityis about
70%ofradial load capacity

17. 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.

18. 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

19. RADIAL AND ANGULAR BEARING

20. Standardization of bearings

21. 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.

22. ROLLERBEARINGS