A spectral identification method for calculating the magnitude of inherent misalignment in a rotor-magnetic bearing system was proposed to study and identify mixed parallel misalignment of the rotor system occurring at the bearing.The momentum moment theorem was used to equate the effect of the disc unbalance force on the rotating shaft to the axial force of the rotor and establish a dynamics model of the rigid double offset disc rotor-magnetic bearing system considering the axial and radial coupling effects.The SIMULINK simulation was used to calculate the displacement and current response of the system in the time domain,and the dynamics characteristics of the rotor system under the misalignment condition were analyzed.Furthermore,the fast Fourier transform was utilized to convert the response in the time domain into that in the frequency domain.The magnitude of the misalignment of the rotor system was then calculated based on the least squares algorithm in the frequency domain.The results show that the error in the calculated magnitude of misalignment by using this method is within 5.0％under the influence of shock excitation,indicating that even if the rotor is affected by external disturbance forces,the algorithm can accurately quantify the rotor's misalignment.This provides a theoretical reference for fault diagnosis and self-repair of misaligned rotor-magnetic bearing systems.
关键词
冲击载荷/轴承-转子系统/不对中量/快速傅里叶变换/轴向径向耦合
Key words
shock excitation/bearing-rotor system/misalignment magnitude/fast Fourier transform/axial and radial coupling
维普
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