What is the elevator brake?
Elevator brake is an electromechanical device, commonly referred to as a brake, and is one of the most critical safety components in an elevator. It is primarily used during elevator stops or emergency braking, playing a vital role in ensuring the safe operation of the elevator. During the elevator’s operation, it performs various safety functions, such as routine parking brake actions, braking for overspeed protection during upward movement, and preventing unintended car movement.
Where is the elevator brake located?
Elevator brakes are usually installed in the elevator machine room and elevator shaft at the top or bottom position. In the machine room, the brake is usually installed by hanging type, while in the shaft, it is usually installed on the ground. This installation location is chosen to ensure that the brake can control the operation of the elevator mainframe in a timely manner, while taking into account factors such as safety and easy maintenance.
What type of brakes are on an elevator?
- Block (Shoe) Brake:
The structure mainly consists of a brake electromagnet, brake arm, brake shoe, and brake spring.
- Disc Brake:
A disc electromagnetic brake is composed of components such as an electromagnetic coil, armature, friction disc, spring, and connecting shaft sleeve.
- Caliper Brake:
A caliper electromagnetic brake is made up of parts such as the armature, brake armature disc, spring, and connecting base.
4.Drum Brake:
The braking force is applied to the drum surface through a lever mechanism, which amplifies the force to generate a high braking torque.
- Band Brake:
Utilizes a brake band as the friction component.Although band brakes are prohibited in certain applications, they may still be used in specific situations.
In addition, according to the braking method: elevator brakes can be divided into mechanical brakes, electromagnetic brakes and hydraulic brakes.
According to the installation position: elevator brake can be divided into traction machine brake, car brake and counterweight brake.
How does an elevator brake work？
When the elevator is in a stationary state, there is no current flowing through the coils of the traction motor and the electromagnetic elevator brake. At this time, due to the lack of attractive force between the electromagnetic cores, the brake pads, under the pressure of the brake springs, tightly clamp the brake wheel to ensure that the motor does not rotate.
When the traction motor is energized and starts rotating, the coil in the electromagnetic brake is simultaneously energized. The electromagnetic core rapidly magnetizes and engages, driving the brake arm to compress the brake spring. This action causes the brake pads to release from the brake wheel, allowing the elevator to operate.
When the elevator car reaches the designated floor, the traction motor is de-energized, and the coil in the electromagnetic brake is also de-energized simultaneously. The magnetic force in the electromagnetic core quickly disappears, and under the action of the brake spring, the core resets via the brake arm. This causes the brake pads to once again clamp the brake wheel, bringing the elevator to a stop.
Elevator brakes are important safety device of the elevator. When the main engine of the elevator operates abnormally, the brake will control the elevator to stop operation immediately through electrical signals, so as to ensure the safety of passengers. Therefore, the role of the brake cannot be ignored during the installation and maintenance of the elevator.
