Rotational speed detection structure of actuator and actuator

A rotational speed detection structure of an actuator, comprising:

• an outer housing, a motor, and a reducer mechanism, wherein
• the motor comprises a stator fixedly fitted to the outer housing, and a rotor matching with the stator and rotatable relative to the stator;
• a shaft sleeve pivotally fitted to the outer housing is synchronously connected to the rotor;
• and the reducer mechanism comprises an input end connected to the rotor, and an output end connected to an encoder shaft extending through the shaft sleeve and coaxial with the shaft sleeve;
• and
• a first mounting surface is disposed on the encoder shaft;
• a second mounting surface is disposed on the shaft sleeve;
• in a radial direction of the actuator, the second mounting surface is located outside the first mounting surface;
• a first magnetic ring is fixed on the first mounting surface;
• a second magnetic ring is fixed on the second mounting surface;
• central axes of both the first magnetic ring and the second magnetic ring coincide with a central axis of the encoder shaft;
• a printed circuit board (PCB) is fixed on the outer housing;
• the PCB comprises a third mounting surface directly facing the first mounting surface and the second mounting surface;
• a first Hall element and a second Hall element are provided on the third mounting surface;
• the first Hall element cooperates with the first magnetic ring to detect a rotational angle of the first magnetic ring to obtain an angle of the encoder shaft;
• and the second Hall element cooperates with the second magnetic ring to detect a rotational angle of the second magnetic ring to obtain an angle of the shaft sleeve.