机床主轴系统静刚度分析及实验研究

为研究机床主轴系统静刚度特性,建立一种高性能加工中心主轴-轴承系统模型,该模型包括主轴转子和轴承。采用有限元法建立主轴轴系零件模型,并与轴承拟静力学模型集成得到主轴系统有限元模型,通过计算得到主轴系统3个方向的静刚度。对该机床主轴系统进行静刚度测试实验,以验证理论计算结果的正确性。研究表明:理论计算结果和实验结果具有较好一致性,因此可以有效地证明该有限元模型的准确性;此外,由于主轴系统内部存在阻尼效应及摩擦作用,卸载时静刚度大于加载时静刚度;同时其轴向静刚度存在一定非线性。

Static Stiffness Analysis and Experimental Study of Spindle System of Machine Tool

In order to study the characteristics of static stiffness of the machine spindle system, a spindle bearing system model of a high performance machining center was established, which including the spindle rotor and the bearing. The components model of spindle system was built by the finite element method (FEM), composed with the quasi static model of the ball bearing, the finite element model of the spindle system was obtained, and the static stiffness of the spindle system was obtained through calculating. The test experiment of static stiffness was carried out to verify the correctness of the theoretical calculation results. The results show that the theoretical calculations and the experimental results are corresponding quite well, so the accuracy of the FEM is proved. Besides, due to the damping effect and friction function inside spindle system, the unloading static stiffness is greater than the loading static stiffness. At the same time, certain amount of nonlinearity of axial static stiffness is existed.