Joint bearing is a special structure of sliding bearing. Its structure is simpler than the rolling bearing. It is mainly composed of an inner sphere with an outer sphere and an outer ring with an inner sphere. It can bear a large load. According to its different types and structures, it can bear the joint load of radial load, axial load or radial and axial. Joint bearings are generally used for low speed swinging motion (angular motion). Because the sliding surface is spherical and can also be tilted in a certain angle range, it can still work normally when the degree of inconcentricity of the supporting axis and the shaft shell is large. It is applied to engineering hydraulic cylinder, forging machine, engineering machinery, automation equipment, automobile shock absorber, water conservancy machinery and so on.