Research On The Dynamics Of Misaligned Rotor-bearing System With A Flexible Laminated Membrane Coupling

The dynamic model of misaligned rotor-bearing system equipped with a flexible laminated membrane coupling was developed by using the method of lumped parameter in this dissertation, and the dynamic behavior, such as the nature characteristics, stability, steady state response of the system, etc. was analyzed based on the theory of linear vibration. The main contributions and conclusions of the work were summarized as follows:Firstly, the static and dynamic characteristics of the laminated membrane were analyzed, and the computing formulas of it stress and stiffness was derived. After discussing the forces on the typical components of the system and their motions, the dynamic model of the flexible laminated membrane coupling-rotor-bearing system was developed, in which the effects of the misalignment and unbalance of the rotor system were considered.The performance of the bearings, the nature characteristics and stability of a symmetric rotor-bearing system equipped with a flexible laminated membrane coupling were discussed duo to misalignment of rotors. The numerical results showed that the effects of the load distributions on bearings and their static and dynamic behavior of the symmetric rotor system by the misalignment were large, meanwhile that of the critical speeds of the system was small. The results also revealed that the modes of the misaligned rotor system were different from the aligned one. When considered the misalignment of rotors, the lowest modes were changed greatly, in which their vibrations of one rotor were fiercer than that of another one generally. Additionally, the misalignment of the system could make the stability have a tendency to deteriorate.The unbalance responses of the rotor-bearing system with a flexible laminated membrane coupling were investigated, in which the effects of the stiffness of the coupling and the misalignment of the rotors were mainly taken into account, respectively. The results displayed that the influences of the responses were different to the angular stiffness of the coupling and the lateral one, that is, the former was large, and the latter small. When the rotating speed passed through the critical speed, the effect of the unbalance response of the system duo to the misalignment was remarkable, and atthe others its influence was not large.