The servo motor is a kind of motor which controls the mechanical components running in the servo system and a kind of device helping motor transmission indirectly. The servo motor can make the control speed, the position very accurate, can transform voltage signal to the torque and the speed to drive the control object.The motor speed is controlled by the input signal, and can respond quickly. In automatic control system, the motor is used for the execution components, with small electromechanical time constant, high linearity and small initiating voltage, can convert the received electronic signal into the output of angular rotation and velocity. There are two kinds of servo motor, DC and AC. The main feature is that when the signal voltage is zero, there is no rotation and the rotation speed decrease evenly with the increase of the torque.
Servo motor is widely used in ATM, printing machine, engraving machine, photo machine, spraying equipment, medical instruments and equipment, computer peripherals and mass storage equipment, precision instruments, industrial control system, office automation, robotics and other fields.