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.该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,该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.%Spindle-bearing, spindle-holder and holder-tool interfaces exist in a NC spindle system, and the characteristics of these interfaces have a 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. A spindle system of a certain vertical machining center was taken as an objective, and its dynamic model was built with the finite element method. Based on it, the contrastive analysis of the inherent characteristic of interfaces was conducted and the influence law of the tool point FRF was studied. The conclusions were described as that the characteristic of the spindle-bearing interface strongly controls the rigid modes of the spindle system and the tool point frequency response function ( FRF) in the range of low frequencies, however, the characteristic of the spindle-holder or the holder-tool interface directly influences the elastic modes and the tool point FRF in the range of high frequencies. The results provided a reference for prediction of dynamic characteristic and stability of a spindle system.
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