电磁轴承振动传递特性研究

摘要

通过有限元方法建立转子的仿真模型，结合电磁轴承动态模型获得整个电磁轴承支承转子闭环系统状态方程。基于该状态空间模型，计算转子受外扰力作用时轴承处力传递率频域响应、在外冲击力作用下位移响应及动态力响应，以此考察电磁轴承的振动传递特性，并与滚珠轴承进行对比。计算结果表明，电磁轴承的刚度阻尼等支承特性与滚珠轴承显著不同，其力的传递率频域响应较平缓，无滚珠轴承支承时某些频率附近的突出峰值。在冲击力作用下电磁轴承支承时，转子位移及动态轴承力振动均能较快恢复稳定状态，振动传递明显减小。%The simulation model of a rotor was obtained with the finite-element-method,and the dynamic model of an active magnetic bearing(AMB)was built.Then,the state-space model of an AMB-rotor system was constructed.With this state-space model,the frequency domain responses of the force transmission rate at the locations of bearings under external disturbance were calculated,and the impulse responses of the rotor displacements and the dynamic bearing force response were simulated too.The vibration transmission characteristics of AMB were studied and compared to those of rolling-ball bearings.It was shown that the stiffness and damping features of AMBs are quite different from those of roll-ball bearings;the frequency domain response of the force transmission rate is quite flat without sharp peaks around some frequencies using roll-ball bearings;with AMBs,the impulse responses of rotor displacements and the dynamic bearing force return to a stable state sooner than those do with rolling-ball bearings,and the vibration transmission is reduced obviously.