关键词: 转子动力学, 主动电磁轴承, 备用轴承, 瞬态响应, 碰撞实验

Abstract: The transient responses of a rotor dropping on a rolling element back-up bearing with a fixed radial clearance after the active magnetic bearing (AMB) failure are measured in a flexible rotor on the AMBs, and the effect is investigated of rotational speed, rotor imbalance and lubrication condition in the contact surfaces of the back-up bearing on the transient response of the rotor system . It is found that in most cases, the motion of the rotor system after the AMB failure is a backandforth oscillation motion with bounces in the bottom half of the clearance circle and a full clearance whirl motion with impact. The transient motion of the rotor system after the AMB failure depends greatly on the vibration of the rotor system, rotational speed at dropping, and lubrication condition in the contact surfaces of the back-up bearing. Changing the lubrication condition in the contact surfaces of the back-up bearing can effectively affect the transient response of the rotor system after the AMB failure, significantly reduce the possibility of the occurrence of full clearance whirl motion with impact and full clearance whirl motion without impact, and reduce the effect of the impact on the rotor and the back-up bearing.

Key words: rotordynamics, active magnetic bearings, back-up bearing, transient response, impact testing