Despite the fact that drum brakes were invented much earlier than modern disc brakes , they still remain relevant for manufacturers and car owners. Such popularity was won due to the simplicity of the design. The brake drum is much simpler, and, accordingly, more reliable and unpretentious than disc brakes.
Production history
And they were invented back in the distant 19th century. The first prototype of modern brakes was a primitive system of only three components. It was actually a brake drum, attached to the wheel, a strong and flexible tape located around it, as well as a lever, pulling the last part. Naturally, the service life of such a system was short-lived, and besides, various stones and dirt fell into it.
The design was improved only at the beginning of the 20th century. Then the engineer Louis Renault invented a new brake drum with more reliable components. For the first time, it included pads located inside the mechanism. The brake device was well protected from dirt, and therefore its service life was significantly increased.
Since then, the brake drum has repeatedly changed its design and materials, but its function has remained unchanged. Such a device still reduced the speed of the car if necessary. It also served as a hand brake.
What does a modern brake drum disc consist of?
The front and rear drums are made exclusively of high-quality and high-strength cast iron. The finished element at the exit is polished from the inside and mounted on the car. The part is mounted on the support shaft or on the wheel hub.
In addition, the following elements are included in the design of the brake drum:
- Brake pads with a special composition of friction material (each manufacturer keeps his manufacturing method secret).
- Hydraulic cylinder (there may be several).
- Protective disk.
- Special latch.
- Coupling springs.
- Self-propelling mechanism.
- Block spacer.
- The mechanism of the pad.
How does the brake drum work?
The principle of operation of this mechanism is as follows. When the driver presses the brake pedal, the driver creates a certain pressure in the working fluid system. It, in turn, acts on the piston of the brake cylinder. After overcoming the forces of the tension spring, the last element activates the brake shoe, diverging on the sides and tightly adjacent to the surface of the drum. As a result, the speed of rotation of the part is significantly reduced, and at the same time, the speed of the car decreases.
Conclusion
As you can see, the composition of the design of the brake drum has really changed a lot over more than 100 years of existence. All technologies used now provide the car with the shortest stopping distance on any road surface. In terms of efficiency, they are not one step inferior to their competitors - disk systems. Therefore, drum brakes are still in high demand among motorists, although recently many car companies have refused to equip their cars with such devices, preferring disc brakes.