The main function of Automobile Wheel Hub Bearing is to bear and provide correct leading for the rotation of wheel hub. It will bear both axial load and radial load and is a very important parts. Traditional automobile wheel bearings are assembled by two sets of tapered roller bearings or ball bearings. The installation, coating, seal and adjustment of clearance of bearings are all processed on the automobile production line. This kind of structure will cause the following problems in automobile manufacturing plant: difficult assembly, high cost and poor reliability. Besides, when the car is maintained at maintaining point, clean, coating and adjustment are needed for the bearing.

Wheel Hub bearing units developed from standard angular contact ball bearing and tapered roller bearing. It integrates these two sets of bearings and has the following advantages: good assembly performance, no clearance adjustment needed, light weight, compact structure, large bearing capacity, pre-installation of lubricating oil for seal bearing, no outer hub seal needed and free from maintenance. It has been widely used in saloon car and has the trend of applying in more lorries.