中文摘要：

基于低温透平膨胀机临界转速的计算，对转子系统结构型式对高速透平膨胀机临界转速的影响进行了分析。用有限元QZ（FEQZ）法求解广义复特征值矩阵，对具有各项异性支承并且支承气膜阻尼不能忽略的高速透平转子临界转速特性进行了研究，并利用求得的复特征向量矩阵推导出了转子分段轴心瞬态振动轨迹方程。讨论了稳态情况下适用于同一透平膨胀机转子4种常用结构振动特性的优缺点。结果表明止推盘双置转子结构在该透平膨胀机设计工况具有较大的转速安全范围和较好的稳定性，此结论与工程应用吻合较好。

英文摘要：

Based on the calculation of turbo-expander critical speed, the influence of different rotor structure types on the critical speed of high speed turbo-expander was investigated. FEQZ method was employed to solve the generalized complex eigenvalue matrix, and the characteristics of critical speed of high speed turbine rotor which has anisotropic support and non-negligible gas film damping were analyzed. The transient vibration equation of segmented axis orbit was concluded from the obtained complex eigenvector matrix. The advantages and disadvantages of vibration characteristics of four different rotor structure types were discussed. The result which is consistent with industrial application show that rotor with two opposed thrust plates has wider safe speed range and better stability.