What is the role of the brake drum in the car brake?

Some people say what is a brake drum? What is the role of the brake in the car? The following road Jie auto parts Xiaobian for everyone to say briefly.

Brake drum is low end car or truck, passenger car only use. As part of a drum brake system, a piston forces two pairs of half-moon shoes against the inner wall of the tympanum, causing friction to stop the wheel from spinning.

To put it simply, it is used to cause brake pads to wear out, and by friction with the brake pads to stop -- stop/slow down.

The gap of the brake drum should be adjusted regularly and the two sides should be the same otherwise it will brake sideways (dangerous).

The advantage of this brake is that it is effective and cheap, but it does not dissipate heat very well, especially on long downhill runs. So big trucks have water squirting on their wheels.