The primary function of an automotive wheel hub bearing is to bear loads and provide precise guidance for the hub's rotation. It withstands both axial and radial loads, making it a critically important component. Traditional automotive wheel bearings consist of two sets of tapered roller bearings or ball bearings combined. The installation, lubrication, sealing, and clearance adjustment of these bearings are all performed on the automotive production line. This configuration presents challenges in automotive assembly plants, resulting in high costs, poor reliability, and the need for bearing cleaning, lubrication, and adjustment during maintenance at service points.

The wheel bearing unit evolved from standard angular contact ball bearings and tapered roller bearings. integrating two bearing sets into a single unit. They offer advantages such as improved assembly performance, elimination of clearance adjustment, reduced weight, compact design, high load capacity, pre-lubrication capability for sealed bearings, elimination of external hub seals, and maintenance-free operation. They are widely used in passenger cars and are increasingly being adopted in commercial vehicles.