楔形入口高度对气体止推箔片轴承性能仿真和试验研究

The Influence of Taper Inlet Height on the Performance of Gas Thrust Foil Bearing: Simulation and Experiment

简要介绍了气体止推箔片轴承的结构,建立了止推轴承数值求解的理论模型,利用有限元法和有限差分法耦合的方式求解气体雷诺方程和气膜厚度方程。通过仿真分析获得了止推轴承承载力随着楔形入口高度的变化关系,发现存在一个最佳的楔形入口高度使轴承的承载力达到最大;在最佳楔形入口高度之前,轴承承载力随着楔形入口高度的增大而急剧增大;在最佳楔形入口高度之后,轴承承载力随着楔形入口高度的增加而缓慢减小。搭建了止推轴承性能测试试验台,对试验台各部分及试验原理进行简单介绍。同时,加工制作了3个具有不同楔形入口高度(20μm,70μm、114μm)的止推轴承,并在15 000 r/min、21 000 r/min、25 000 r/min、28 000 r/min转速下进行了极限承载力试验,与仿真分析进行对比。结果表明:楔形入口高度为20μm的止推轴承所表现出来的轴承性能最好,楔形入口高度为70μm和114μm的止推轴承性能相差不大。在设计、制造止推轴承时,选取适当的轴承楔形入口高度是十分重要的。

The structure of gas thrust foil bearing is briefly introduced and the theoretical model of thrust bearing is established. The gas Reynolds equation and gas film thickness equation are solved by the coupling of the finite element method and the finite difference method. The relationship between the bearing load capacity and the taper inlet height is obtained by simulation. It is found that there is an optimal taper inlet height to maximize the bearing load capacity. The load capacity increases sharply with the increase of taper inlet height before the optimal taper inlet height, and the load capacity decreases slowly with the taper inlet height after the optimal taper inlet height. The test rig of thrust bearing is built, and each part of the test rig and the test principle are briefly introduced. At the same time, three thrust bearings with different taper inlet heights(20 μm, 70 μm, 114 μm) were manufactured. The limited load capacity measurement was carried out at 15 000 r/min, 21 000 r/min, 25 000 r/min and 28 000 r/min and compared with the simulation results. The results showed that the thrust bearing with taper inlet height of 20 μm performs the best, and the performance of the thrust bearing with taper inlet height of 70 μm and 114 μm has little difference. Therefore, it is very important to choose the appropriate taper inlet during thrust bearing designing and manufacturing.