数控机床主轴系统热态性能仿真、试验及优化方法研究

Simulation,Experiment and Optimization Method for Thermal Characteristic of a Machine Tool Spindle System

本文以立式加工中心为对象,重点研究了其主轴系统热态性能(温度场、热变形)仿真、试验及优化方法.基于建立的机床实体模型,提出了热特性仿真中有限元边界条件:热源、换热系数和零件间接触热阻等参数的计算及获取方法,对该机床的温度场和热变形进行了仿真,分析了主轴系统的热态性能及对整机热特性的影响,并通过热特性试验验证了仿真模型的准确性.研究表明:主轴系统温升主要集中在主轴轴承和主轴电机部位,主轴Y、Z两向热变形较大,主轴热特性对其他零件影响较小.通过改变主轴箱冷却槽的结构和尺寸,对主轴系统的热特性进行了优化,并通过仿真验证了优化的有效性.

The thermal characteristic of a spindle system is simulated by finite element method. Temperature field and thermal deformation of the spindle system were simulated considering the establishment method of entity model as well as boundary conditions of finite element model, such as heat source, heat transfer coefficient and thermal contact resistance between joints. Effects of the spindle system on thermal characteristic of whole machine were discussed. Accuracy of the simulation was verified compared with test.The study shows that key areas of temperature rise locate at spindle bearing and spindle motor; thermal deformation of Y and Z directions are large; thermal characteristic of the spindle system has little influence on other parts. Thermal characteristic of the spindle system was optimized by changing structures and sizes of the cooling passage located at spindle box, and effectiveness of the optimization was verified by finite element simulation.