Bearing is one of the important parts in modern mechanical equipment.Its main function is to support the mechanical rotating body, reduce the friction coefficient in the process of motion, and guarantee the accuracy of its rotation.
According to the different nature of the friction of the moving element, the bearing can be divided into two categories: rolling bearing and sliding bearing. The rolling bearings have been standardized and serialized, but compared with the sliding bearing its radial dimension, vibration and noise, the price is higher.
Generally bearing outer ring, inner ring, rolling body and a holding frame is composed of four parts, strictly speaking, is composed of an outer ring, inner ring, rolling body, a retainer and a sealing and lubricating oil six parts. In simple terms, as long as have the outer ring, inner ring and rolling element can be defined as for rolling bearings. According to the shape of rolling, rolling bearing for ball bearings and roller bearings two categories.