Thrust ball bearings, as the name suggests, contain balls as the rolling elements in them. “Thrust" suggests that the bearings are basically designed for carrying thrust loads or axial loads. The image below shows the constructional aspects of both variants of thrust ball bearings. (Hover mouse to read the label or click the image to enlarge.)
The bearings are basically available in two configurations as follows:
- Single row thrust ball bearings
- Double row thrust ball bearings
The basic construction of the thrust ball bearings consists of
- Two races that tend to hold the rolling element or the ball in between them. The balls in turn are held together as a single element by means of the cage.
- The bearing by construction is separable, i.e. the races as well as the rolling element assembly with the cage can be mounted separately.
Some constructional features of the single row thrust ball bearings:
- It consists of two races with a single row of rolling elements in between them, due to the above feature; the single row thrust ball bearing is capable of carrying axial thrust in only one direction.
Some constructional features of the double row thrust ball bearings:
- It consists of three races with two rows of rolling elements sandwiched in between them. This feature enables the bearing to carry axial thrust loads or reversing axial loads in both directions.
Assembly and Mounting Constraints:
- The bearing must be ensured of a particular minimum axial thrust load for it to perform perfectly. Non-application of any axial load will lead to undesirable working kinematics of the bearing. In order to overcome this, the bearing must be preloaded by spring in order to ensure the minimum axial load.
- One care should be ensured for the mounting and assembly of the thrust ball bearings: the mounting surface on the housing must be parallel to the raceway of the bearing.
- Bearings with numbers starting in 532 and 533 have a spherical housing locating race which permits the bearing to take up misalignments.
- By construction on of the outer race possess a bore of round size equivalent to that of the shaft size and normally as multiples of 5 like diameter 20, diameter 60, etc. This round size race is the one that abuts with the mating face. The other race which does not carry the axial load is normally at the opposite end.
- The thrust ball bearings normally start with the series 5. For Example, 51105.
- The bearing is available in both metric and inches.