Wheel bearing is one of the key parts of automobiles. Its main function is to carry weight and provide precise guidance for the rotation of the wheel. This requires it to bear not only axial load but also radial load.

Traditional automobile wheel bearings are composed of two sets of tapered roller bearings or ball bearings. The installation, oiling, sealing and clearance adjustment of the bearings are all carried out on the automobile production line. This structure makes it difficult to assemble in automobile production plants, high cost, and poor reliability, and the bearings need to be cleaned, oiled and adjusted when the automobile is maintained at the repair point.

The hub bearing unit is developed on the basis of standard angular contact ball bearings and tapered roller bearings. It combines two sets of bearings as a whole. It has good assembly performance, can omit clearance adjustment, light weight, compact structure, and load capacity. Large, sealed bearings can be pre-loaded with grease, omit external wheel hub seals, and are free from maintenance. They have been widely used in cars, and there is a trend to gradually expand their applications in trucks.