The main function of the hub bearing is to support the load and provide precise guidance for the rotation of the hub. It bears both axial and radial loads and is a very important component. 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.