I. Overview The servo system is a mechanical motion driving device, the motor is the control object, the controller is the core, and the power electronic power conversion device is the actuator, under the guidance of automatic control theory, the electrical transmission automatic control system is formed.
As the actuator of CNC machine tools, the servo system integrates power electronic devices, control, driving and protection, with the advancement of digital pulse width modulation technology, special motor material technology, microelectronics technology and modern control technology, it has experienced the development process from stepping to DC and then to AC.
There are many kinds of servo systems in CNC machine tools. This paper analyzes its structure and simple classification, and briefly discusses its technical status and development trend.
Second, the structure and classification of the servo system, from the basic structure, the servo system is mainly composed of three parts: Controller, power drive device, feedback device and motor (Figure 1).
The controller adjusts the control amount according to the difference between the given value of the numerical control system and the actual operating value detected by the feedback device;
As the main circuit of the system, the Power Drive device acts the electric energy in the power grid onto the motor according to the control amount on the one hand, and adjusts the torque of the motor, on the other hand, according to the requirements of the motor, the power supply of the constant voltage constant frequency grid is converted into the AC or DC required by the motor; The motor is driven by the power supply.