导轨速度对静压导轨承载性能的影响

Influence of Guide Rail Speed on Bearing Performance of Hydrostatic Guide

竖直液体静压导轨是纳米数控精密加工机床关键装备,机床静压导轨的运动速度不仅对零件加工精度有影响,也对导轨油膜承载性能有影响。因此确定机床导轨最佳工作速度就十分有必要。以纳米曲面磨床静压导轨油膜为例,通过Fluent流体仿真,对导轨运动速度与油膜最高压力、最低压力、油膜承载力定量的研究得到:在相对静止状态下,油腔压力场呈对称分布;导轨的运动速度增加,会产生油膜承载的不平衡性;验证了油膜负压对导轨承载性能影响很小,可以忽略;提出了纳米数控磨床的最佳静压导轨运动速度范围为0~0.1 m/s及0.3~0.5 m/s;在该工作速度范围内导轨的承载性能较好。研究结果为精密机床闭式静压导轨的工作参数选定提供了一定的依据。

Vertical liquid static pressure guide rail is the key equipment of nanometer Numerical Control （NC） precision machi-ning. The movement speed of hydrostatic guide rail is not only influenced by the machining precision of parts, but also on the bearingperformance of oil film. So it is very necessary to determine the best working speed of the machine tool guide rail. The nano-surfacegrinding machine static pressure guide film is taken as an example. Through the Fluent simulation of fluid, it was gotten by analysis ofthe track speed and maximum pressure, minimum oil film pressure, oil film bearing capacity： quantitative in relative static state, theoil cavity pressure field is with symmetrical distribution ; velocity of rail increases, which will produce imbalance of oil film bearing; oilfilm pressure on the rail to verify the capacity is very small, which can be neglected; the nano NC grinder best hydrostatic guide waymovement speed range is 0 m/s to 0. 1 m/s and 0. 3 m/s to 0. 5 m/s; in the speed range, the guide rail bearing performance is quitegood. This study provides some theoretical significance for the selection of working parameters of closed hydrostatic guide for precisionmachine tools.