(1) The
belt actuator has the advantages of simple structure, large wrap angle, large braking torque, large bending force on the brake axle, and uneven specific pressure and wear of the brake belt. The braking torque of simple and differential belt brakes is related to the rotation direction, which limits the application range. Poor heat dissipation, suitable for large machines and compact braking, such as the braking of machine tools, mobile cranes, hoists, etc.
(2) The
block actuator has the advantages of simple and reliable structure, general heat dissipation, sufficient and uniform retreat of the pad and convenient adjustment. For the straight brake arm structure, the braking torque has nothing to do with the steering of the brake shaft. The brake shaft is not subject to bending stress, but the wrap angle and braking torque are small. The manufacturing is more complex than the belt brake, the lever system is complex and the overall dimension is large. Block brake is the most widely used. It is mainly used in machinery with frequent work and large installation space, such as hoisting and transportation, metallurgical machinery, etc.
(3) The
internal expansion shoe actuator uses two built-in brake shoes to squeeze the brake drum radially outward to produce braking torque. Compact structure, good heat dissipation and easy sealing. Most of them are normally open. They are often used in occasions where the installation space is limited. They are widely used in the braking of wheeled cranes and walking mechanisms of various vehicles (such as cars, tractors, etc.).
(4)
Disc actuator uses axial pressure to compress the disc or conical friction surface to realize braking. When the full disc or point disc is symmetrically arranged, the brake shaft is not subject to bending force. The structure is compact, the tile is worn evenly, and the braking torque is independent of the rotation direction. When used for dust and moisture protection, it can be made into a sealed type. The heat dissipation of point disc type is good, and the heat dissipation of full disc type is poor. It is especially suitable for occasions with high compactness requirements, such as vehicle wheel electric hoist.
(5)
The magnetic particle actuator uses the internal force generated by magnetic particle magnetization to brake. The utility model has the advantages of small volume, light weight, small exciting power, and the braking torque has nothing to do with the rotating speed of the rotating parts. The magnetic powder will cause the wear of the parts. It is mainly used for braking (adjustable braking torque), precision positioning, test loading, tension control, etc.
(6) The magnetic eddy current actuator is durable, easy to maintain and has a wide adjustment range. However, at low speed, the efficiency is low and the temperature rises, so heat dissipation measures must be taken. It is often used in machinery with vertical load (such as the lifting mechanism of hoisting machinery) to absorb the function before parking, so as to reduce the load of parking brake.
