基于单向流-固耦合的高精密液体静压主轴应力场和温度场研究

Research on Characteristics of the High Precision Hydrostatic Spindle System Base on One-way Fluid-Solid Interaction

高精密液体静压主轴系统正常工作时,系统不均匀的温度分布、润滑油膜的压力分布都会造成应力集中和主轴系统结构变形,导致主轴过早失效。基于单向流-固耦合理论,以FLUENT和Workbench为联合仿真平台,对液体静压主轴的力-结构变形和热-结构变形以及应力分布进行分析研究。分析表明:主轴工作达到稳态后,轴承静压腔内的压力分布均匀,回油槽以及出口位置的温度梯度大,平均温度高于油垫的温度;静压轴承润滑油膜的压力和温度分布对主轴的径向变形影响更为明显,进而影响主轴的刚度;电主轴转子的温升是影响主轴应力集中的主要因素,对主轴工作的油膜间隙影响不明显。

When the hydrostatic spindle system work normally, the uneven temperature distribution of the system and the pressure dis- tribution of the oil film can cause stress concentration and structure deformation of spindle system that might lead to the shaft premature fail- ure . Based on the one-way FSI and FLUENT-workbench co-simulation platform, the force-structure deformation, heat-structure deforma- tion and the stress distribution of the hydrostatic spindle were studied. The results show that the pressure in bearing static pressure cavity is distributed uniformly and the temperature gradient is large at the location of return chute and export and the average temperature is higher than that of the oil cushion when the hydrostatic spindle stops working. Oil film pressure and temperature distribution of the hydrostatic bearing have obvious effect on the radial deformation of the spindle and affect the spindle static stiffness. The rotor temperature rise of the electric spindle has no obvious effect on the radial deformation in the support position of the hydrostatic bearing but the main factor influen- cing the spindle stress distribution.