基于结合部动力学特性的立柱-主轴系统动力学模型研究

针对某卧式加工中心动力学特性分析的需要,论述了主要影响其动力学特性的立柱-主轴系统中导轨结合部、螺栓结合部、滚珠丝杠结合部以及轴承4类结合面分布情况,提出各类结合部动力学参数提取方法与有限元建模方法.通过试验测试与有限元分析相结合的手段识别导轨结合部刚度与阻尼,利用赫兹接触理论计算出滚珠丝杠接触刚度.在此基础上,建立了某卧式加工中心立柱-主轴系统有限元分析模型,通过测试立柱-主轴系统轴端频率响应函数验证了该有限元分析模型的准确性,并分析得出了该立柱-主轴系统导轨结合部对系统动态性能的影响情况.

Column-spindle System Dynamic Model Based on Dynamic Characteristics of Joints

For the needs of dynamic analysis of the horizontal machining center, the distribution of linear guide, bolt joints, ball screw and bearing which main affect the dynamic characteristics of column-spindle system were discussed, then the dynamic parameters identifying method and finite element modeling method for these joints were presented. The stiffness and damping of linear guide were identified by the combination of experimental tests and finite element analysis, and the ball screw contact stiffness was calculated based on Hertz contact theory. On this basis, the finite element model for the column-spindle system of a horizontal machining center was established. The accuracy of the finite element analysis model was verified by testing the tool point frequency response function of column-spindle system. Then influence of linear guide for the dynamic characteristics of column-spindle system was analyzed.