中文摘要：

针对高速气体润滑轴承-转子系统存在低频振动现象，考虑气膜压力与弹性支承对轴系振动特性的影响，开展低频振动特性实验研究。采用了轴系模态分析方法，得到不同轴承供气压力下的转子的模态固有频率，采用非线性测试及分析方法，研究了低频振动及其抑制后的轴心轨迹、频率耦合三维谱图、频谱图和分岔图等非线性特征，结果表明：基础下加硅胶垫后，能够降低转子通过临界转速的幅值，推迟低频振荡的发生。

英文摘要：

For sub-synchronous vibration of high speed rotor-bearing system with gas lubrication, taking into account the in- fluences of gas film pressure and elastic spacer on the characteristics of shaft vibration an experiment study on the characteristics of sub-synchronous vibration was carried out. Using modal analysis the modal frequencies of the rotor system under dif- ferent supply gas pressures were obtained. Based on nonlinear methods for test, measurement and analysis the sub-syn- chronous vibrations and the nonlinear characteristics, such as the shaft center orbits, frequency coupling 3-D plot, bifurcation plot,etc after control were studied. The results show that by adding silica gel spacer under the base the vibration amplitude can be reduced when passing the critical speed of the shaft and the occurrence of sub-synchronous vibration can be postponed too.