The braking direction of a band brake depends primarily on its structural design and operating principle. Band brakes use friction to slow or stop a vehicle. Basic configurations include simple, differential, and combined types.
Simple Brake
The simple brake design is shown in the figure. One end of the brake band is fixed to the lever fulcrum A, and the other end is connected to point B. Under the action of gravity, the brake band presses against the brake drum surface, generating friction torque, thereby braking. When the electromagnet is energized, the brake band separates from the drum, releasing the brake.
Differential and Combined Brakes
Differential and combined band brakes are more complex in structure. They simultaneously tighten the brake band at points B and C, ensuring uniform braking torque regardless of drum rotation. This design is suitable for bidirectional braking applications and provides constant braking torque.
Operating Principle
Band brakes operate based on friction. When the pressure oil is filled into the servo cylinder through the oil channel, it pushes the piston to compress the return spring, and the brake band is clamped on the brake drum through the piston connecting rod. The static brake band and the rotating brake drum rub against each other, and finally the brake drum is fixed, achieving braking. When the pressure oil is released, the return spring pushes the piston to reset, and the brake band and the brake drum restore the free gap, achieving brake release.