The servo motor can control the speed, the position accuracy is very accurate, can convert the voltage signal into torque and speed to drive the control object. The rotor speed of the servo motor is controlled by the input signal and can react quickly. In the automatic control system, it is used as an execution element,and has the characteristics of small electromechanical time constant and high linearity, so the received electrical signal can be converted into the angular displacement or angular speed output on the motor shaft. Servo mechanism is an automatic control system that enables the position, orientation, state and other output amount of an object to follow any change of the input object (or a given value). Servo mainly by pulse positioning, basically can understand, servo motor received a pulse, will rotate a pulse corresponding Angle, so as to realize the displacement, because, servo motor itself has the function of the pulse, so servo motor each rotating Angle, will send the corresponding number of pulse. The assembly is convenient, the assembly process of the front end cover and the machine body is reduced, and the installation of screws of the front end cover is saved. Good concentricity and verticality aft assembly. Servo motor is widely used in medical instruments and Equipment, computer peripherals and massive storage equipment, precision instruments, industrial control systems, office automation, robots and other fields.