The angular contact ball bearing is divided into angular contact ball bearing,doule row angular confact ball bearing and four point contant ball bearing .It can bear radial and axial roads at the same time and can bear pure axial load as well with higher limiting speeds .The capability of bearing axial load is determined by the degree of contact angle,The bigger the contact angleis ,the bigger the axial load can be borne. The contact angles are classified as 15o