Rolling bearings normally comprise bearing rings, rolling elements and a cage.

Rolling elements are arranged between inner and outer rings with a cage, which retains the rolling elements in correct relative position, so they do not touch one another. With this structure, a smooth rolling motion is realized during operation.

There are many types of bearings such as Deep Groove Ball Bearing, Angular Contact Ball Bearing, Cylindrical Roller Bearing, Spherical Roller Bearing, Tapered Roller Bearing, Thrust Ball Bearing, Needle Roller Bearing and etc.