Abstract: The dynamic response characteristics of the internal rotor⁃bearing system are directly related to the pros and cons performance of the turbine.In this paper, the finite element method is used to model the rotor⁃bearing system, considering the effect of bearing stiffness on the critical speed of the system, the unbalanced response characteristics at the same speed and different speeds,the unbalanced response characteristics are discussed in detail, the sensitive position of the system is determined, which provides the basis for the optimization design of the steam turbine.

Key words: Rotor?bearing system, The finite element method, Critical speed, Unbalance response, Sensitivity degree

摘要： 汽轮机内部转子-轴承系统的动力响应特性直接关系到其使用性能的优劣。使用有限元法对转子⁃轴承系统进行了建模，考虑轴承刚度对系统临界转速的影响，对同一转速和不同转速下的不平衡响应特性进行了详细讨论，确定了系统的敏感位置，为汽轮机的优化设计提供了理论依据。

关键词: 转子?轴承系统, 　有限元, 　临界转速, 　不平衡响应, 　敏感程度。