Bus & Truck Brake Linings Motorcycle Brake Linings
Drum brake is a brake that uses friction caused by a set of shoes or pads that press outward against a rotating cylinder-shaped part called a brake drum. Drum braking linings have brake drums that rotate with the wheels.
Brake shoes fitted with brake linings (friction material) which press against the drums from the inside to generate braking force (decelerate and stop) are set inside of the drums.
With this system, friction is generated by pressing the brake linings against the inside surfaces of the drums. This friction converts kinetic energy into thermal energy. Drum rotation helps to press the shoes and the lining against the drum with more force, offering superior braking force in comparison with disc brakes. On the other hand, it is very important to design the components so that the heat from the thermal energy is dissipated efficiently into the atmosphere.
There are three types of drum brakes depending on how the brake shoes are pressed on to the drums; leading/trailing shoe type, twin leading shoe type and duo-servo type.
Structure of drum brakes
Drum brakes are a brake system with brake drums (rotor) which rotate with the wheels. Inside each drum are brake shoes fitted with brake linings (friction material). Pistons (pressure mechanism) press against the drums from the inside to generate braking force, thus making is possible to decelerate and stop the vehicle.
How drum brakes work
When the driver steps on the brake pedal, the power is amplified by the brake booster (servo system) and changed into hydraulic pressure (oil-pressure) by the master cylinder. The pressure reaches the brakes on the wheels via tubing filled with brake oil (brake fluid). The delivered pressure pushes the pistons on the brakes of the four wheels. The pistons press the brake linings, which are friction materials, against the inside surfaces of the brake drums which rotate with the wheels. The linings are pressed on the rotating drums, which in turn decelerate the wheels, thereby slowing down and stopping the vehicle.
Main components of drum brakes
Manufacturing process of friction materials