The bearing is a part of the support shaft, with the rotation of the leading shaft or the use of the parts on the shaft, the bearings can be divided into rolling bearings and plain bearings. Generally speaking, the bearings refer to the rolling bearings.

The basic structure of the rolling bearing:
Rolling bearings generally by the inner ring, outer ring, tumbling body and cage structure, during which the effect of sliding bearing inner ring is matched with the shaft, and with a shaft of a composite bearing with the rotation, the outer ring effect is matched with the bearing Support the effect of tumbling body is through the cage evenly on the rolling body distributed between the inner ring and the outer ring, the shape of the size and quantity directly affect the use of rolling bearings and the number of life, the cage can make the rolling evenly distributed, To avoid rolling roll fall, guide the rolling body rotation from the smooth effect.