Servo Motor/ Stepper Motor/Brushless Motor

The common characteristic of servo motor, stepper motor, brushless motor : all of them are brushless, and the speed is controlled by electric signal when operation.

Stepper motor and AC servo motor are common control motors, both of them using the electric pulse from digital producer to control the speed of motor. Brushless motor uses the Hall sensor, that is, controlling the motor speed by input voltage.

These three sorts of motors have obviously difference in speed regulation accuracy, so their application occasions are different. The speed regulation accuracy of servo motor is the highest, which is generally used in precised positioning, such as the movement of machine arm in flow line; Stepper motor is the secondary, the higher the speed of stepper motor, the smaller the torque. Therefore, it is applicable for the low speed and high torque occasion, and usually applied in the work of CNC machine tools; The brushless motor only roughly adjusts the speed,. The higher the speed, the higher torque, so it is more suitable for high speed. Due to the poor accuracy of brushless motor, it is not suitable for precision control, and it is is frequently used in electric vehicles.

Comparing brushless motor and stepper motor, brushless motor will rotate a while even the power failure. However, the servo motor and stepper motor react very quickly. But stepper motor has the phenomenon of step loss in the high speed state. The same condition will not appears in the servo motor. Servo motor is constant torque, featuring high stability. The torque is always the same whether the speed is high or low.