摘要
针对超精密气浮工作台内部微小间隙气体的性能展开研究,实现了微尺度下气体滑移及黏度对气浮工作台性能影响的分析。基于气体润滑理论和微尺度下气体滑移和黏度的研究,实现了气浮工作台内气膜流态模型的修正,利用有限差分法给出了雷诺方程的数值求解过程;通过求解修正模型,分析不同供气压强和气膜间隙下,滑移和黏度对气浮工作台性能影响的机理。研究结果表明:气体滑移和黏度会引起气浮工作台承载力的降低和气膜刚度的增大,但不会改变供气压强和气膜间隙对工作台的影响趋势,只是影响程度发生改变,当同时考虑滑移和黏度时,承载力比忽略时降低最多(约为21.95%),最大刚度比忽略时提升最大(约为15%)。滑移和黏度的存在使得气浮工作台的实际性能最优参数小于理想的最优性能参数,最优气膜间隙由原来的10μm变为6μm。最后,通过试验验证发现,同时考虑气体滑移和黏度时,气浮工作台的性能最接近实际工况,承载力的仿真曲线与试验曲线最吻合,刚度的试验值与仿真值的误差约为9.59%。
Based on the study on the performance of gas in an ultra-precision air bearing stage,the effects of velocity slip and viscosity at micro scale on the performance of air-bearing stage are studied.The modified film flow model was established by the theory of gas lubrication and the research of slip and viscosity in micro scale.The numerical solution of the Reynolds equation is obtained by the finite difference method.The influences of slip and viscosity on performance of air-bearing stage at different gas supply pressures and gas film clearances are analyzed by solving Reynolds equations.The result shows that the loading capacity is smaller and the stiffness is larger when considering the slip and viscosity,while the influencing trend of gas supply pressure and gas film clearance on the air bearing stage is kept the same,only the degrees of change are affected.When the slip and viscosity are taken into account at the same time,the loading capacity is decreased by 21.95%,and the maximum stiffness is increased by 15%.The optimum performance parameters of the air bearing stage are less than the ideal optimum performance parameters when slip and viscosity are considered.The optimum gas film clearance is changedfrom the original 10μm to 6μm.Finally,the test results showed that when the slip and viscosity are considered at the same time,the stiffness of the air bearing stage is close to the actual working condition.The simulation curve of the loading capacity is in good agreement with the test curve,and the average error between the test and simulation values is about 9.59%.
作者
陈东菊
董丽华
潘日
范晋伟
CHEN Dongju;DONG Lihua;PAN Ri;FAN Jinwei(Beijing Key Laboratory of Advanced Manufacturing Technology, Beijing University of Technology, Beijing 100124, China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2017年第11期63-70,143,共9页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金资助项目(51475010
51105005)
关键词
气浮工作台
滑移
黏度
承载力
刚度
air bearing stage
velocity slip
viscosity
loading capacity
stiffness
