The research on the dynamic characteristics of rotor has experienced from linear theory to nonlinear theory, and the research and development of simple “rotor” towards the complex system including bearings, seals and other components. Scholars at home and abroad have made a lot of research and accumulated a lot of research results. The results lay a foundation for the comprehensive analysis and study of rotor dynamic characteristics.
As early as 1919, Jeffcott, a British dynamo, studied a single disk elastic rotor with rigid supports at both ends, and established a model named Jeffcott rotor. This rotor model is a simplification of the real rotor, and also lays the foundation for the study of rotor dynamics. This is the first revolution about rotor dynamics. Because the rotor model established by Jeffcott is very simple, Stodola and green introduced the moment of inertia of the disk into the system. Considering the possible gyroscopic effect, a Stodola green rotor model is established, which is more complex than Jeffcott’s rotor. This model can better explain the vibration characteristics of the actual rotor. In recent years, in the research of rotor system dynamics, the rotor is only a functional component in the system, because the research on the dynamic stability of rotor system can not only be related to a single rotor part, so “rotor dynamics” is gradually replaced by “rotor bearing system dynamics” in the continuous evolution process. So far, many studies have shown that there are many excitation factors, such as the excitation force of the seal and the damping of the rotor system, which may affect the dynamic characteristics of the system.
Since the first symposium on sealing and rotor system dynamics held in 1980, NASA has held annual seminars on sealing, and many research reports related to sealing have been published every year. Children et al. Studied the dynamic stability of the rotor system with different sealing structures and drag reduction measures. Zutavern ZS and childs DW studied the dynamic stability of the sealed rotor with magnetic bearings under the influence of different sealing parameters.