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.

To effectively overcome the shortcomings of conventional air bearings,a new style squeeze film air bearing is developed according to the ultrasonic wave suspension and piezoelectric effect.