真空环境下小孔节流径向气浮轴承特性研究

Research on the Characteristics of Radial Gas Bearings with Small Orifice Restrictors in a Vacuum Environment

单轴气浮台中的涡流力矩主要是由径向气浮轴承的制造误差引起的。采用CFD软件首先研究了真空环境对小孔节流径向气浮轴承的承载力、耗气量的影响规律,其次对比研究了真空环境下简化和实测常见制造误差对涡流力矩的影响规律。在常压和真空环境下,进、出口压力差相同时,常压环境下静态承载能力优于真空环境;当出口压力逐渐越接近真空时,承载力下降趋势更加突出;在真空环境下的平均耗气量要比常压下小。对简化的制造误差进行分析时,涡流力矩出现正弦周期性变化,其峰值出现规律与制造误差的相对位置有关。依据实际误差测量数据进行建模分析,发现涡流力矩在一定范围内波动,这是轴颈制造误差与节流孔直径制造误差共同作用的结果,峰值数量和位置与节流孔的数量和相对位置一致,且节流孔直径制造误差也会对峰值时的涡流力矩结果产生影响。

The eddy torque in the single-axis air floating platform is mainly caused by the manufacturing errors of the radial air floating bearings.CFD software was used to first study the influence patterns of the vacuum environment on the carrying capacity and gas consumption of the orifice-throttled radial air floating bearings,and then the patterns of the simplified and measured common manufacturing errors′ effects on the eddy torque under vacuum environment were compared and analyzed.Under normal and vacuum environments,when the inlet and outlet pressure differentials are the same,the static load-carrying capacity of the normal environment is superior to that of the vacuum environment.When the outlet pressure gradually approaches vacuum,the decreasing trend of the carrying capacity becomes more pronounced;the average gas consumption under vacuum is smaller than under normal pressure.When analyzing the simplified manufacturing errors,the eddy torque shows a sinusoidal periodic variation,and its peak occurrence pattern is related to the relative position of the manufacturing error.Based on actual error measurement data,the modeling analysis finds that the eddy torque fluctuates within a certain range,which is the result of the joint effect of the shaft neck manufacturing error and the orifice diameter manufacturing error.The number and position of the peaks are consistent with the number and relative position of the orifices,and the orifice diameter manufacturing error also affects the results of the peak eddy torque.