直驱型高速数控机床进给系统设计分析及实验

Design Analysis and Experiment of High Speed CNC Machine Tool Feed System Driven by Liner Motor

为克服传统机床"旋转电机+滚珠丝杠"进给传动方式存在的弹性变形大、响应速度慢、易磨损等问题,利用永磁直线同步电机(PMLSM)设计了一种直线电机驱动高速数控机床进给系统。从理论上分析了系统机械结构对动态特性的影响,在此基础上,对最大切削力工况下的进给系统主体结构进行了刚度、强度以及模态分析,最后,实验测试了进给系统的位置精度及动平衡精度。结果表明,该进给系统结构变形量小于0.01mm,最大应力为5.7MPa,且在低阶频率范围内,主动避开1、2、5、6阶加工激振频率可使进给系统具有较高的抗振特性,同时该系统的位置精度、平衡精度均在设计指标内,有效的保证了进给系统主体结构的动态精度及稳定性。

In order to overcome the problems of traditional feed drive way composed by spin motor combined with ball screwin machine tool,such as high elastic deformation,slowresponse speed and easy to wear,a high speed CNC machine tool feed system driven by liner motor was designed using permanent magnet linear synchronous motor（ PM SM）. The influence of mechanical structure on the dynamic characteristics was analyzed theoretically. On the basis of this,the stiffness,strength and modal analysis of the main structure of the system were made under the working condition of the maximum cutting force. Finally,the position precision and dynamic balance precision of the feed system were tested. The results showthat the deformation of the system structure is less than 0. 01 mm and the maximum stress is 5.7M Pa. And in lowfrequency range,a high anti vibration characteristics of the feed system can be obtained by avoiding 1,2,5,6 order processing excitation frequency. At the same time,the system position precision and balance precision both meet the design index,and dynamic precision and stability of main structure of the feed system are guaranteed effectively.