Bearing is an important component in contemporary mechanical equipment. Its main function is to support the mechanical rotating body, reduce the friction coefficient during its movement, and ensure its rotational accuracy.

According to the different frictional properties of moving components, bearings can be divided into two categories: rolling bearings and sliding bearings. Rolling bearings have been standardized and serialized, but compared to sliding bearings, they have larger radial dimensions, vibration, and noise, and are also more expensive.

Rolling bear-ings are generally composed of four parts: outer ring, inner ring, rolling element, and cage. According to the shape of rolling elements, rolling bearings are divided into two categories: ball bearings and roller bearings.