When to use a reducer for a brushless stepper motor

The power supply of the brushless stepping motor is connected to the brushless motor through the controller, so that the brushless motor can run in one direction. From the direction of the motor shaft extension, the clockwise rotation of the motor shaft is called forward rotation, and the counterclockwise rotation is called reverse rotation. In the following two cases, the brushless motor needs to consider the adjustment of the motor rotation direction: (1) If the brushless motor rotation is found to be forward rotation, but the actual motor is reverse, the rotation direction of the motor must be adjusted. (2) If the working state of the brushless motor is forward rotation in a certain state and time, and reverse rotation in another state and time, then the correct rotation of the motor must be controlled according to the working state and time of the brushless motor. motor. Generally, during the operation of a DC motor, changing the direction of the magnetic field or the polarity of the armature voltage can change the direction of the motor. The magnetic flux of a brushless DC motor is generated by permanent magnets, which cannot change its direction. In addition, due to the unidirectional conductivity of semiconductors, the inversion of the power supply voltage is also inconvenient. Therefore, in this case, the rotation direction of the motor is generally changed by controlling the commutation sequence of the stator windings.

Brushless stepper motors use reducers in the following situations

(1) The stepper motor switches the frequency of the stator phase current, such as changing the input pulse of the stepper motor drive circuit to make it a low speed. When the low-speed stepper motor is waiting for a step command, the rotor is at a standstill. When pedaling at low speeds, the speed fluctuations can be large. At this time, if it is changed to high-speed operation, the speed fluctuation problem can be solved, but the torque will be insufficient. That is, the torque fluctuates at low speeds, and the torque is insufficient at high speeds.

(2) The step angle of the small (below 50mm) PM type stepping motor is 7.5°. This type of motor has the problem of variable position control accuracy.

(3) The output shaft of the stepping motor adopts the method of directly driving the load. When the load crown beam is large, the acceleration moment will be insufficient.

(4) Occasions where low-speed high-torque braking is required.