Traditional car wheel with bearing is composed of two sets of tapered roller bearings or ball bearings back to back or face to face, the installation of the bearing, oil seal and clearance adjustment is carried out on the auto production line. This structure makes it in the car factory assembly difficulty, high cost and poor reliability, and when the car in pits maintenance, also need to clean, oil bearing and adjustment.
Prime Wheel hub bearing unit is in the standard of angular contact ball bearings and tapered roller bearing and develops on the basis of, it will be two sets of composite bearing directly into a one-piece (double row angular contact ball bearings and double row circular cone roller bearings), one-piece wheel hub bearing unit has the assembly performance is good, can be omitted configured in advance clearance clearance adjustment, bearing, light weight, compact structure, large load capacity, inject grease and seal installation in advance (oil), omit the advantages of external wheel seal and free from maintenance, has been widely used in cars, in a truck also has a tendency to gradually expand the application, the use of the wheel hub bearing unit and the usage is growing, now has developed into the third generation.