Abstract:

A mathematical model of feed system of an CNC machine was established using Lagrange equation and energy principle, and the influences of parameters on the vibration displacement of workbench were analysed. According to the results of orthogonal tests, it is concluded that the biggest three factors that influence workbench's vibration displacement are the ball screw's lead h, the table mass m and the longitudinal contact stiffness kn in the connection of the table and ball screw. On the feed system test-bed, the longitudinal amplitudes and torsional amplitudes of workbench were measured, they show that the larger the ball screw's lead and  the mass of the workbench the bigger, the greater the axial amplitude of the workbench; and the longitudinal contact stiffness in the connection of workbench and ball screw, the smaller the axial amplitude of the workbench.

Key words: ball-screw, workbench, vibration displacement, orthogonal test

摘要：

利用拉格朗日方程和能量原理建立了数控机床进给系统的数学模型,分析了各参数对工作台振动位移的影响。按正交试验的结果,得出了影响工作台振动位移最大的3个因素,分别为丝杠的导程h、工作台的质量m和工作台与丝杠连接的纵向接触刚度kn。在进给系统试验台上测量滚珠丝杠的轴向振幅及扭转振幅,得出与理论分析相同的结果,即:丝杠的导程越大,工作台的质量越大,工作台的轴向振幅越大;工作台与丝杠连接的纵向接触刚度越大,工作台的轴向振幅越小。

关键词: 滚珠丝杠, 工作台, 振动位移, 正交试验