主轴系统结合面对主轴系统动力学特性的影响分析

数控机床主轴系统存在着主轴-轴承、主轴-刀柄、刀柄-刀具结合面，这些结合面的特性对主轴系统动力学有着显著的影响，而获得该影响规律对于主轴系统动态设计及动力学修改有着重要意义。本文以某立式加工中心主轴系统为对象，采用有限元法对其进行了动力学建模，在此基础上，对比分析了结合面特性对该主轴系统固有特性和刀尖点频响函数的影响规律。具体可以描述为：主轴-轴承结合面特性影响主轴系统的刚体模态和刀尖点低频段的频响函数；而主轴-刀柄结合面、刀柄-刀具结合面特性直接影响主轴系统的弹性模态和刀尖点高频段频响函数。此外，本文研究也可为主轴系统动力学特性及稳定性预估提供参考。

Effect analysis of the interface on spindle system dynamic characteristics

Spindle-bearing，spindle-holder and holder-tool interfaces exist in the NC spindle system, and the characteristic of these interface has the significant influence on the spindle system dynamics. It is important to obtain the influence law for the dynamic design and modification of the spindle system. The paper takes a spindle system of vertical machining center as its object and builds the dynamic model with the finite element method, based on which, the contrastive analysis researches the inherent characteristic of interfaces and the law of influence of tool point FRF. The conclusion can be described as follow: the characteristic of spindle-bearing interface strongly controls the rigid modal of spindle system and tool point frequency response function (FRF) of low frequencies, however, the characteristic of spindle-holder and holder-tool interface directly influences the elastic modal and tool point FRF of high frequencies. Besides, the paper also could provide reference for the dynamics characteristic and stability forecast of spindle system.