Deep groove ball bearing is the most production and the most widely used product. The basic deep groove ball bearing consists of an outer ring, an inner ring, a set of steel ball and a set of cage. In addition to basic open type, there is single-dust Z type, double-dust 2Z type, single-sealed RS type, double-sealed 2RS type, N type with snap ring on the outer ring and other variant structures. Mainly used to bear radial load, but also could withstand small two-way axial load. With small friction coefficent and high limit speed, this kind of bearing can provide high precision, low noise and high quality products. However, such kind of product can not be split installation, meanwhile the self-aligning capability is also low.