Deep groove ball bearing is the most representative rolling bearing. Compared with other types of bearings with the same dimension, the bearing has small friction coefficient, high speed limit, simple structure, low manufacturing cost and high precision. It needn’t regular maintenance and has large size range and many forms. The bearing is most widely used one. It is mainly subjected to radial load, but also withstands certain axial load. When it is only subjected to radial loads, the contact angle is zero. In addition, this type of bearing also has certain self-aligning ability. When inclining 2 '~ 10' relative to the shell hole, it still works, but the bearing life is subject to certain impact.