Actuator

In the industrial brake industry, an actuator refers to the power source or power conversion unit within a brake. It is responsible for converting one form of energy—such as electrical, hydraulic, or pneumatic energy—into mechanical force or torque. This drives the brake’s mechanical components (e.g., brake pads, brake arms) to generate friction, thereby achieving braking or release actions.

Simply put, if the brake is viewed as a system, the actuator is its “heart” or ‘muscle’—the core component that makes the brake “move.”

Based on energy source, the most common actuator types in industrial brakes include:

Electromagnetic Actuator: Utilizes the magnetic field generated by an energized electromagnetic coil to engage or release the armature. This is the most prevalent type, widely used in servo motor safety brakes, elevator traction machine brakes, and similar applications.
Hydraulic Actuator: Drives a piston using high-pressure oil supplied by a hydraulic station to generate substantial thrust. Commonly employed where extreme braking force is required, such as in wind turbine yaw/pitch brakes and port crane brakes.
Pneumatic Actuator: Utilizes compressed air to drive the piston. It offers fast response, clean operation, and minimal contamination, making it ideal for precision applications like tension control.
Spring Actuator: A specialized yet critical actuator commonly found in fail-safe brakes. Its braking force is provided by a powerful pre-compressed spring, while external energy sources (electric, hydraulic, pneumatic) act to overcome the spring force and release the brake. Upon loss of power or pressure, the spring immediately pushes the brake pads to lock, ensuring safety.
From a professional perspective, discussing brakes cannot be separated from their actuator type. The choice of actuator directly determines the brake’s stopping force, response speed, control method, cost, and whether it possesses “fail-safe” characteristics. Therefore, accurately describing a brake typically involves specifying “hydraulic fail-safe brake” or “electromagnetic power-off brake,” where ‘hydraulic’ and “electromagnetic” refer precisely to their actuator types.