高速透平机械全金属鼓泡箔片动压气体轴承稳定性研究

Stability Analysis for Fully Hydrodynamic Gas-Lubricated Protuberant Foil Bearings in High Speed Turbomachinery

为了验证高速透平机械中鼓泡箔片轴承完全取代传统静压轴承的可行性,将全金属鼓泡箔片径向轴承和鼓泡箔片止推轴承同时应用在主轴直径为25mm、产量为150m3/h工业制氧机用的高速透平膨胀机上,进行了全动压鼓泡箔片轴承透平膨胀机的实验研究,实验用的鼓泡箔片径向轴承采用周向叉排,鼓泡箔片止推轴承采用径向叉排。实验结果表明:透平转子在全动压鼓泡箔片轴承透平膨胀机上能够稳定运行,表现出良好的动态性能和稳定性;由于良好的柔弹性结构、惯性小等特点,鼓泡箔片轴承能够迅速适应转子运动;随着转子转速的升高,转子轴心轨迹由不规则半圆环状逐渐变成规则的圆环状,在多次重复性实验中轨迹重复性较好;鼓泡箔片轴承可有效抑制转子涡动,转子能够在高转速下持续稳定运行。

To verify the feasibility of substituting protuberant foil bearing for traditional hydrostatic bearing in high speed turbomachinery,both metallic protuberant gas foil journal bearings and thrust bearings were applied to a high speed turboexpander with rotor diameter of 25 mm for 150 m3/h industrial oxygen production.The protuberant gas foil journal bearings were circumferentially staggered and the protuberant gas foil thrust bearings were radially staggered.Test results indicate that the rotor is able to operate stably under fully hydrodynamic gaslubricated protuberant foil bearings to show the favorable dynamic property and stability.The protuberant foil bearings are quickly adapted to rotor motion due to the compliant elasticity and low inertia.With increasing rotor speed the rotor orbit varies from irregular semi-circularity to regular circularity,and the good repeatability appears in repetitive tests.Whirling motion of the rotor can be suppressed effectively to guarantee stable rotor operation at high speeds.