In this paper, a rotordynamic experiment on a compressor rotor system is presented and the feasibility of gas foil bearings with inhomogeneous bump foils is verified. A push–pull device is designed to obtain the stiffness curve and the nominal clearance of foil bearings. Operating points and dynamic coefficients of the rotor system at each rotating speed are predicted. In rotordynamic analysis, an alternative model of the impeller is proposed and the critical speed is predicted by employing the finite element method, in which the dynamic coefficients of inhomogeneous foil bearings are taken into account. Compared with the experimental result, the accuracy of the prediction for the critical speed is verified to be about 14% error. Two sets of foil bearings with 22 and 41 μm nominal clearance are manufactured and tested. Test results indicate that the vibration amplitude can be greatly reduced by diminishing the bearing clearance. When foil bearings with 22 μm clearance are used, the high-order harmonic frequencies of rotor vibration are significantly inhibited, and the amplitude of the rotating frequency is obviously restricted. Thus, the foil bearing with inhomogeneous bump foils tested in this paper can meet the speed requirement of the compressor when the nominal clearance is set at 22 μm.

本文提出了在压缩机转子系统上的转子动力学实验，并验证了具有不均匀凸块箔的气体箔轴承的可行性。设计了推拉装置，以获取箔轴承的刚度曲线和标称间隙。预测了每个转速下转子系统的工作点和动态系数。在转子动力学分析中，提出了一种叶轮的替代模型，并采用有限元方法预测了临界转速，其中考虑了不均匀箔轴承的动态系数。与实验结果相比，临界速度的预测精度被证实为约14％的误差。制造并测试了两组标称间隙为22和41μm的箔轴承。测试结果表明，通过减小轴承游隙可以大大降低振动幅度。当使用间隙为22μm的箔式轴承时，转子振动的高次谐波频率被显着抑制，并且旋转频率的幅度明显受到限制。因此，当标称间隙设置为22μm时，本文中测试的带有不均匀凹凸箔的箔轴承可以满足压缩机的速度要求。