steel & cast iron
The scientific name of the brake hub is the brake drum, which is the main component of the drum brake system. The friction between the inner surface of the brake drum and the brake pads during the braking function. The brake drum is a cast iron piece shaped like a tambourine, which is fixed to the tire and rotates at the same speed.
A brake is a component of a braking system that generates a braking force that obstructs the movement of a vehicle or the tendency of a movement. Except for various retarding devices, automobile brakes are almost all friction brakes that use the friction between the fixed element and the working surface of the rotating element to generate a braking torque.
At present, the friction brakes widely used in various types of automobiles can be divided into two types: drum type and disc type according to different rotating elements. The difference between them is that the rotating element in the friction pair of the drum brake is a brake drum, with the inner surface of the cylinder as the working surface; the rotating element in the friction pair of the disc brake is a disc-shaped brake disc, and Both end faces are working surfaces.
When braking, oil pressure is used to push the brake shoes to contact the inner edge of the brake drum, and the friction generated by the contact is used to suppress the rotation of the tire to achieve the purpose of braking. Generally speaking, the brake hub is like a metal drum or a small bucket that is placed on the hub, and the bottom of the bucket is rubbed against the hub of the car to stop it when braking.
The brake drum is an important component of the drum brake system. The inner surface of the brake drum of the drum brake is where the braking device generates a braking torque. With the same braking torque, the diameter of the brake drum of a drum brake device can be much smaller than that of a disc brake. Therefore, in order to obtain a powerful braking force, a large vehicle used for loading can only install a drum brake in a limited space of a rim. Drum brake systems are typically installed on the rear wheels of large vehicles.