The development and application of NC machine tool servo system (英语论文).doc

The development and application of NC machine tool servo system Since the invention of NC machine tool in 1950s, servo system has been the indispensable component of the NC machine tool. With the rapid development of new materials, electronic power and controlling system, the servo system has evolved from the step-by-step system to DC system and then to AC system. As the blossom of AC servo technology, AC servo system will replace the DC system wholly and take up the dominant position in the family of servo system. with the electronic power conversion unit as actuator and controller as core , Servo system which contains the servo driver and servo motor constitutes the main part of the electric-driving and automatic control system . When working, firstly the servo system will receive the signal from NC devices, and then drive the motion of machine tool as well as ensure the accuracy and speediness of movement under the guidance of pulse command . Usually, precision and speed of the NC machine tool and other technical indicators mainly depend on the servo system itself The improvement and assortment of NC servo system At present, engineers tend to assess the quality by reference to several important indicators, such as precision, speed and so on. Therefore, a NC servo system must meet these requirements. High precision Unlike the traditional manufacturing which can be manually handled to regulate and compensate errors, the NC servo system has a high demand on positioning accuracy and repeated positioning accuracy Quick repose characteristic Quick response is one of important indicators of servo system’s dynamic quality which requires the servo system following the command signal with minimum error as well as quick repose and high stability. Once receiving the instruction of manipulator, the working machine can restore the original state of equilibrium quickly after a short regulation or a disturbance from outer space. Wide speed range Due to the difference in