离心空压机波箔气体轴承设计及实验研究

针对功率26 kW、主轴径22 mm的氢燃料电池离心空压机，设计波箔动压气体轴承；在搭建的实验台上进行轴承静动态特性实验和耐久性实验，得到轴承滞回曲线和静态刚度曲线，以及空压机轴系升降速振动三维频谱图、30 000~95 000 r/min下的时域图。实验结果表明：研发的波箔动压气体轴承静态刚度与轴承位移具有非线性特性；空压机启停100 000余次后，平箔表面仅有轻微磨损，波箔高度几乎无变化，表明轴承具有良好的耐久性；转子振动以基频为主，全转速范围内主振幅为1 μm左右，无明显低频和高频振动；两级气浮轴承离心空压机实验最高工作转速可达95 000 r/min，并且表现出良好的热力性能。

Esign and Experimental Study on Bump-Foil Gas Bearing Used in Centrifugal Air Compressor

The bump foil dynamic gas bearing was developed for the hydrogen fuel cell centrifugal air compressor with a rated power of 26 kW and a spindle diameter of 22 mm.The static and dynamic characteristics experiments and durability experiments of the bearings were carried out on the built experimental bench,and the bearing hysteresis curves and static stiffness curves were obtained,as well as the three-dimensional spectrum diagram of the air compressor rotor system’s acceleration and deceleration vibration,and the time domain diagram from 30 000 r/min to 95 000 r/min.The experimental results show that there exits a nonlinear characteristics between the static stiffness and the displacement of the bearing.After more than 100 000 times of starts and stops of the air compressor,there is only slight wear on the surface of the flat foil,and there is almost no change in the height of the bump foil,indicating that the bearing has good durability.The rotor vibration is mainly on the fundamental frequency,the main amplitude is about 1 μm in the full speed range,and there was no obvious low-frequency and high-frequency vibration.The maximum stable speed of the two-stage air bearing centrifugal air compressor can reach 95 000 r/min,and it exhibits good thermal performance.