Type of Rolling Contact Bearing

For starting condition and at moderate speeds, the frictional loss in rolling contact bearing are lower than that of equivalent hydrodynamic journal bearing hydrodynamic journal bearing.

1. Deep Groove Ball Bearing: In this, the radius of ball is slightly less than the radii of curvature of the groove
in the races. This gives a point contact. Due to point contact, there will be less friction loss resulting in less temperature rise and less noise, so maximum permissible speed is high.

Advantages:

• Due to large ball size, the load carrying capacity will be high.
• It can take load in axial as well as radial direction.

Disadvantages:

• Self alignment is not possible.
• Poor rigidity due to point contact compared with roller bearing.

2. Cylindrical Roller Bearing: It is used when maximum load carrying capacity is required in a given space.

Advantages:

• It gives a line contact so more rigid, thus radial load carrying capacity is high.
• Frictional loss is less in high speed application.

Disadvantage :

• In general, it cannot take thrust load.
• Self alignment is not possible.
• Generates more noise.

3. Angular Contact Bearing: In this, the grooves in inner and outer races are so shaped that the line of reaction
at the contact between balls and races makes an angle with the axis of bearing.

Advantages:

• It can take both radial and axial load.
• Load carrying capacity is more than deep groove ball bearing.

4. Self-aligning bearing: In self-aligning bearing, the external surface of the bearing bush is made spherical.
The centre of this spherical surface is at the centre of the bearing. Therefore, the bush is free to roll in its seat
and align itself with the journal.
Arrangement is made to provide lubrication between the spherical surfaces of the bush and its seat in order to reduce the friction. It is used in agricultural machinery, railway axle-boxes.

• Self aligning bearing is used to compensate misalignment and can take both radial and axial load both.
• This has less load carrying capacity compared to spherical roller bearing.

5. Taper Roller Bearing: They are arranged in such a way that the axes of individual rolling elements intersects
at a common apex point on the axis of the bearing. This is an essential requirement of pure rolling motion between conical surfaces.
When it is subjected to pure radial load, it induces a thrust component and vice-versa.

Advantages:

• It can take heavy radial and thrust load both
• It is more rigid
• It can be easily easily dispersed/assembled.

Disadvantages:

• Two bearings are required to balance axial force.
• Pre-load is required.
• It cannot tolerate mis-alignment.

Applications:

Car, truck, differential, propeller shaft, railroad axle-box, large size bearing in rolling mills.

6. Thrust ball bearing: A thrust ball bearing consists of a row of balls running between two rings-the shaft ring
and the housing ring. Ball and inner/outer races are made of high carbon chromium steel and roller made of case hardened steel. It is used in gear boxes.

Advantages:

Large number of ball result in high thrust load carrying capacity.

Disadvantages: 

• It can carry thrust in only one direction.
• It cannot carry radial load.
• It is not self-aligning.
• It performance is good only for low and medium speeds.
• It requires application of continuous pressure applied by spring to hold the rings together.
  Applications: Worm gear boxes, crane hooks.