Drum brakes - the so-called brake system, which consists of a rotating drum. In it, braking is achieved by pressing the brake pads against the drum.
As usual, pads in such a system asdrum brakes, are located inside the drum. If they are located on the outer side of a cast-iron flat disc, then this mechanism is called disk. Drum brakes are still of a different kind - tape. In such a mechanism, braking is carried out by "covering" the drum with a braking metal flexible band.
In such a device, which has two workerscylinder, the performance is increased by rotating the drum when the car is moving. During braking, it presses the pads even harder. There is no such effect on the disk mechanisms, since the disk rotates in the direction that is perpendicular to the direction of the braking force. When the machine moves forward, the front shoe starts acting. It is also referred to as a secondary brake shoe (otherwise it is called the rear brake shoe).
It is worth mentioning, what are the main elementshas a drum brake. These are the pads that brake. For this, they have lining made of friction material. Also in its complete set there is a brake drum, brake and wheel cylinders. The first of the special liquids listed under pressure, which is in the hydraulic system, comes into play from the brake pedal. All listed parts are mounted on a brake plate (stamped base).
In addition, the drum brakes have pins (axles)brake pads, mechanisms that regulate the gap between the drum and pads, the springs that hold the pads in their places and reduce them after the driver releases the brake pedal.
And, of course, it is impossible not to list advantagesof this mechanism. It is used on trucks (most often) and cars. Still can apply on motorcycles. The main advantage of this mechanism is its power. Or rather, the fact that it is extremely easy to increase by increasing the drum diameter and width. Due to this, it is possible to achieve high absolute values of braking force, which are necessary to stop and slow down heavy transport (buses, trucks). Drum brakes are perfectly protected against water and dust, or rather from their impact. Pads on dirt or dirt road less wear out - this is an excellent quality, which makes the mechanism durable. If you use it, you can greatly simplify the equipment of the vehicle parking brake. In addition, such mechanisms do not emit much heat, and thanks to this, non-hygroscopic brake fluids based on alcohol-oil base can be used. Such advantages and have rear drum brakes. It is worth noting only one drawback - the reaction they have a little slower, compared with disk.