High Temperature Resistance brake drum for Heavy Duty Truck
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.
Normal braking
When the brakes are applied, brake fluid is forced under pressure from the master cylinder into the wheel cylinder, which in turn pushes the brake shoes into contact with the machined surface on the inside of the drum. This rubbing action reduces the rotation of the brake drum, which is coupled to the wheel. Hence the speed of the vehicle is reduced. When the pressure is released, return springs pull the shoes back to their rest position.
Automatic self-adjustment
As the brake linings wear, the shoes must travel a greater distance to reach the drum. When the distance reaches a certain point, a self-adjusting mechanism automatically reacts by adjusting the rest position of the shoes so that they are closer to the drum. Here, the adjusting lever rocks enough to advance the adjuster gear by one tooth. The adjuster has threads on it, like a bolt, so that it unscrews a little bit when it turns, lengthening to fill in the gap. When the brake shoes wear a little more, the adjuster can advance again, so it always keeps the shoes close to the drum. Typically the adjusters only operate when the vehicle is going in reverse and the brakes are engaged.
Integral casting The brake drum is integrally cast from high-strength gray cast iron or alloy cast iron containing Cr. This brake drum has a simple structure, convenient processing, and large heat capacity, but has a large mass, and is mostly used for medium and heavy vehicles.
Combination of steel plate and cast iron The brake drum is composed of a steel plate stamped drum plate and a cast iron drum ring, which has a small mass and is mostly used for cars and light cars.
Combination of light alloy and cast iron The main body of the brake drum is a light alloy material (such as aluminum alloy), which is lined with a cast iron ring. This kind of brake drum is not only small in weight, but also good in heat dissipation, and is mostly used in cars.
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.