铸造式和焊接式主轴箱体的动态特性对比分析

利用有限元法和试验模态法对立式加工中心的铸造式和焊接式两种结构的主轴箱体进行了模态分析,分别获得了其前六阶固有频率和振型。通过对比两种方法获得的结果,验证了有限元分析模型的有效性。研究表明,两种主轴箱体的阻尼比接近,但焊接式主轴箱体的各阶固有频率均要高于铸造式主轴箱体的各阶固有频率。并且铸造式主轴箱体的固有频率更接近于机床主轴的常用工作频率,焊接式主轴箱体的则远离此频率。因此对于常用主轴转速而言,焊接式主轴箱体的动态性能要优于铸造式主轴箱体的动态性能。

Comparative analysis of dynamic characteristics for the casting and welding spindle box

The dynamic characteristics of the spindle box have important influence on the vibration performance of the whole vertical machining center.In order to study the dynamic characteristics of the spindle box of vertical machining center after adopted the welding parts instead of the casting,this paper got the first six order natural frequencies and modal shapes of the casting and welding spindle box of vertical machining center by means of the finite element method and the experimental method.Comparing the results obtained from this two methods,the validity of the finite element analysis model was verified.The results show that the damping ratios of the two kinds of spindle box are close,but every natural frequency of the welding spindle box is higher than that of the casting one.Moreover,the natural frequencies of the casting spindle box is closer to the common working frequency of the machine tool’s spindle,while the welding’s is far away from this frequency.Therefore,in terms of the commonly used spindle speed,the dynamic performance of the welding spindle box is better than that of the casting one.