Wheel bearing is one of the key parts of the car, its main role is to carry the weight and provide accurate guidance for the rotation of the wheel hub, which requires it not only to withstand the axial load but also to withstand the radial load. Conventional bearings for automotive wheels are made up of a combination of two sets of tapered roller bearings or ball bearings, and the mounting, greasing, sealing, and clearance adjustment of the bearings are all carried out on the automotive production line. Wheel hub bearing unit is developed on the basis of standard angular contact ball bearings and tapered roller bearings, it will be two sets of bearings as one, with good assembly performance, can omit clearance adjustment, light weight, compact structure, large load capacity, for sealed bearings can be loaded with grease in advance, omit the external hub seals and maintenance-free, etc., has been widely used in sedans, and also in the heavy-duty vehicles to gradually expand the application of the trend. In the past, wheel bearings for cars were most often used in pairs with single row tapered roller or ball bearings. With the development of technology, cars have been widely…