1. Bearings are divided into:

(1) Radial bearings - mainly used for rolling bearings that bear radial loads, and their nominal contact angles range from 0 to 45 degrees. 

According to the different nominal contact angles, it is further divided into: radial contact bearings - radial bearings with a nominal contact angle of 0;

radial angular contact bearings - radial bearings with a nominal contact angle greater than 0 to 45 degrees.

(2) Thrust bearings - mainly used for rolling bearings bearing axial loads, and their nominal contact angles are greater than 45 to 90 degrees. 

According to the nominal contact angle, it is divided into: axial contact bearings - thrust bearings with a nominal contact angle of 90 degrees; thrust angular contact bearings

- thrust bearings with a nominal contact angle greater than 45 but less than 90 degrees.

2. Bearings are divided into:

(1) Roller bearings - the rolling elements are rollers. According to the types of rollers, roller bearings are further divided into: cylindrical roller bearings -

bearings whose rolling elements are cylindrical rollers, and the ratio of the length to diameter of the cylindrical rollers is less than or equal to 3mm;

(2) Needle roller bearings - the rolling elements are needle roller bearings, the ratio of the length to diameter of the needle rollers is greater than 3, 

but the diameter is less than or equal to 5mm;

(3) Tapered roller bearings - bearings whose rolling elements are tapered rollers.