Wheel hub bearing is a key component in wheel hubs of automobiles, motorcycles and other vehicles. The following is a detailed introduction to it:

Structure and composition

The hub bearing usually consists of inner ring, outer ring, rolling element and retainer. The inner ring is fixed with the hub, and the outer ring is connected with the steering knuckle or axle housing of the vehicle. Rollers are typically balls or rollers that roll between the inner and outer races to reduce friction. The retainer is used to fix the rolling elements so that they are evenly distributed to avoid collision and friction.

Operational principle

The main function of the hub bearing is to support the hub so that the wheel can rotate smoothly. When the vehicle is running, the hub bearing bears a variety of loads from the weight of the vehicle, the impact force generated by uneven road surface and the braking force during braking. These loads are converted into rolling friction through the rolling of the rolling elements between the inner and outer rings, greatly reducing the energy loss and improving the driving efficiency and performance of the vehicle.

Classification

Classified according to structure form: deep groove ball bearing, angular contact ball bearing, tapered roller bearing, etc. Deep groove ball bearing is applicable to bear small radial load and certain axial load, and is commonly used for hubs of small cars and motorcycles. The angular contact ball bearing can bear radial and axial loads at the same time, and can bear large axial force. It is generally used for vehicles with high requirements on steering performance. Tapered roller bearing can bear large radial and axial combined load, and is commonly used in the hub of heavy-duty vehicles such as cargo trucks and large buses.

Classified by seal form: open bearing and sealed bearing. The open bearing has no sealing device, so additional sealing parts shall be added during installation, which is applicable to some occasions easy to be lubricated and maintained. Sealed bearing is equipped with sealing device, such as rubber seal ring or metal seal cover, which can effectively prevent dust, water and other impurities from entering the bearing, and keep the lubricating oil in the bearing, reducing the maintenance cost and frequency, and widely used in various vehicles.

Materials and Properties

The wheel hub bearing is usually made of high carbon chromium bearing steel, which is characterized by high strength, high hardness, good wear resistance and corrosion resistance. It can withstand various complex loads during the driving process of the vehicle to ensure the service life and reliability of the bearing. At the same time, in order to improve the performance and service life of the bearing, the bearing surface will be subject to such heat treatment processes as quenching and tempering to obtain better structure and mechanical properties.