高速铣床主轴-轴承的振动特性分析

Analysis of Vibration Characteristic of Spindl⁃Bearing System of High Speed Grinding Machine

主轴是高速铣床的核心部件,其动力学特性直接影响铣床的加工精度。以德国GMN某型高速铣床电主轴为例,采用有限元方法,建立了主轴-轴承系统的有限元模型,研究了主轴的固有振动特性,分析了轴承刚度对主轴固有振型和临界转速的影响。在此基础上,研究了高速主轴的不平衡响应特性,分析了不平衡量大小和位置等因素对主轴振动敏感度的影响规律,发现主轴两端不平衡响应敏感,尤其是连接刀具的一端振幅明显,研究结果可为高速机床主轴系统的动力学设计提供一定的参考。

The spindle is the core part of the high speed milling machine,its dynamic characteristics directly affect the machining accuracy of the milling machine.Taking a German GMN high⁃speed milling machine electric spindle as an example,the finite element method was used to establish a finite element model of the spindle⁃bearing system,the natural vibration characteristics of the spindle were studied,and the influence of bearing stiffness on the natural vibration mode and critical speed of the spindle was analyzed.On this basis,the unbalanced response characteristics of the high⁃speed spindle were studied,and the influence of the unbalance amount and position on the vibration sensitivity of the spindle was analyzed.It was found that the unbalanced response at both ends of the spindle was sensitive,especially at the end where the tool was connected.The results could provide a certain reference for the dynamic design of the high⁃speed machine tool spindle system.