?In the previous news, we had some knowledge of disc brakes. So, who is better, drum brake or disc brake? Which is more convenient to use and more effective?
First, let's take a look at the drum brakes:
Drum brake is also called block brake. It is achieved by pressing the brake pad on the brake wheel.
Drum brake is an early-designed braking system. The design of its brake drum has been used in carriages since 1902, and it was not widely used in the automotive industry until around 1920.
At present, the mainstream of drum brakes is the internal tension type. Its brake pads (brake shoes) are located on the inner side of the brake wheel. When the brake is applied, the brake pads open outward and rub the inside of the brake wheel to achieve the purpose of braking.
Contrast with disc brakes:
Compared with disc brakes, drum brakes have much worse braking performance and heat dissipation. Drum brakes have poor braking force stability, and the braking force varies greatly on different roads, which is not easy to control.
Due to the poor heat dissipation performance, a large amount of heat can be accumulated during braking. Under the influence of high temperature, the brake pads and drums are prone to extremely complicated deformation, which is prone to brake decay and chattering, which causes the braking efficiency to decrease.
In addition, after using the drum brake for a period of time, it is necessary to periodically adjust the gap of the brake shoes, and even to remove the entire brake drum to clean up the accumulated brake powder. Of course, the drum brake is not useless. It is cheap and conforms to the traditional design.
During the braking process of a four-wheeled car, the load of the front wheel usually accounts for 70% to 80% of the total load of the car due to the effect of inertia. The braking force of the front wheel is greater than that of the rear wheel. In order to save costs, manufacturers use the brake method of the front disc and the rear drum.
However, for heavy vehicles, because the speed is generally not very high, and the durability of the brake shoes is higher than the disc brakes, many heavy vehicles still use a four-wheel drum design.
The working principle of a drum brake is basically the same as that of a disc brake: The brake shoe presses against a rotating surface, which is called a drum.