Dyanmic Characteristic Reserch Of Bearing Rotor System Of The High Speed Permanent Magnetic Starting Generator

For rotating machinery, especially the work speed is much higher than the first-order critical speed , the inherent of bearing rotor system such as critical speed will affect the stability of rotating machinery. The most common problem of stability is vibration, vibration of rotor system dramatically, not only affect the performance of generators, many kinds of accidents may occur, the resulting is high-speed generator working irregular.This article started to study high-speed permanent magnet generators, the speed required to achieve about 100000r/min. Working speed is much higher than the first-order critical speed. Study as a rigid shaft has not achieved the desired effect, So study it as a flexible rotor.In this paper, the theory of the dynamics is the basis. Transfer matrix is established to calculate the critical speed of the model; also improved Riccati is used to solve the root's problem of leakage and wrong; with the help of computing software such as Pro / e, MATLAB, ANSYS and so on , we can calculate the parameter of the model and design the program to calculate the critical speed. A software to calculate critical speed has been developed using MATLAB.In the factors of critical speed, the bearing stiffness and bearing stiffness are two aspects of the analysis, in which the bearing stiffness study from three aspects: the bearing preload, the contact angle, rotor speed. The critical speed, mode shape calculations of high-speed permanent magnet starter-generator is calculated based on dynamic stiffness.Based on theoretical analysis, carried out on the hammer transient excitation experiments to analyze the natural frequency of the bearing pedestal, bearing support stiffness and other modal parameters; Signal collection of the working rotor bearing is used to analysis the reason of vibration generated during working, real-time spectrum from the high-speed permanent magnet starter-generator to find the critical speed; critical speed obtained from the experiment with changes in bearing preload law; adjusted according to changes of the critical speed of proposed measures.Finally, the critical speed of the rigid coupling - rotor system, a flexible coupling - rotor system are analyzed and compared.