Automotive wheel bearings for the main role is to load and rotate the wheel to provide accurate guidance, both axial load and radial load, is a very important component. Traditional automotive wheel bearings is composed of two tapered roller bearings or ball bearings combination, installation of bearings, oiling, sealing and clearance adjustment is carried out in the automotive production line. This structure makes it difficult in the car assembly plant, the high cost, poor reliability, and vehicle maintenance in the maintenance point, but also the need for bearing cleaning, oiling and adjustment. Wheel hub bearing units are the standard angular contact ball bearings and tapered roller bearings based on the developed, it will be two sets of bearings as a whole, with assembly performance, and can be omitted clearance adjustment, light weight, compact structure, the load capacity large, as can be pre-loaded grease sealed bearings, hub seals and external omitted from maintenance, etc., have been widely used in cars, in the truck also has a tendency to gradually expand the application.
