A brief introduction to the servo system of CNC machine tools
September 03, 2023
The execution parts and mechanical transmission parts on the machine tool constitute the feed system of the CNC machine tool. It controls the feed speed, direction and displacement of the executing parts according to the speed and displacement commands sent by the numerical control device. Each feed movement executive part is equipped with a servo system. The role of the servo system is to convert the pulse signal from the numerical control device into the movement of the moving parts of the machine tool. It is equivalent to the hand of the manual operator, so that the worktable (or slide plate) can be precisely positioned or make a relative movement according to the specified track. Finally, parts that meet the requirements of the drawings are machined.
In recent years, servo motor control technology has developed more and more rapidly. It is in full swing in the three directions of communication, digitalization, and intelligence. As the implementing agency of CNC machine tools, the servo system integrates power electronics, control, drive, and protection, and has experienced advances in digital pulse width modulation technology, special motor material technology, microelectronics technology, and modern control technology. From step-to-step, and then to the development of communication.
The servo system consists of a servo-driven motor and a servo drive. It is the executive part of the CNC system. The drive components that drive the movements of the CNC machine actuators include spindle drive units (mainly speed control), feed drive units (mainly speed control and position control), spindle motors, and feed motors. In general, the servo drive system of numerically-controlled machine tools requires good and fast response performance, as well as the ability to accurately and accurately track command functions. The servo system of CNC machine tools includes stepping motor servo system, DC servo system and AC servo system. Now the latter two are commonly used. All of them are equipped with position detection elements such as inductive synchronizer and encoder, while AC servo system is replacing DC servo. system.
