Disc brakes in all respects better than drum brakes do? Not necessarily! If you see a drum brake say this car is not kind, it would be too cost reduction across the board, and some of the advantages characteristic drum brake is a disc brake can not be replaced. Now say, in the automotive field, the disc brake drum brake will be fully phased out too early.
Inherent structural characteristics from birth drum brake drum brake determines the braking force from a single aspect is far more than the disc brakes. The name comes from drum brakes to keep pace with the movement of the brake drum wheel, due to the shape of a drum, the brake system is called Drum Brakes
Brake drums and wheel movement to keep pace in the brake drum is usually housed two brake shoes, rear brake pedal, a hydraulic mechanism will pedal force to the brake shoe, two semicircular shaped brake shoes to expand outward pressing under pressure, then the brake shoe and the brake drum to form a strong friction large area, thereby generating a braking force.
Why say drum brake braking force is larger than the disc it? In addition to more friction area than most fundamental institutional characteristics of the drum brake will bring the braking force amplifying effect, when the brake shoe is pressed against the brake drum, fixed shoe itself is suppressed due to the reaction force of the brake shoes the brake drum rotation direction, resulting in a certain distortion. At this time the shoe being fixed rotational direction of the brake drum friction reaction force becomes large, this is the brake drum braking force amplification sources. Due to the vehicle by means of a forward roll energy, but also do not like the disc brake vacuum booster needs the engine, so that more direct braking effect the drum brake in the brake force is superior to single disc brake.
The disc brake although the overall structure is more complicated, but in principle, the principle of the brake disc brake structure is actually simpler brake disc brakes with brake drum wheel together with the same operation, the brake calipers and brake in a normal state plate without friction. When the required braking force presses the brake pedal, the brake caliper hydraulic unit to the direction of extrusion brakes, friction is also use to get the braking force. But the problem is, there is no way to get disc brakes like drum brakes as the braking force amplifying effect, alone obviously can not force themselves to get greater braking force, therefore, have a disc brake booster vacuum device is a drum brake are not It has. Drum brake biggest advantage is also visible.