Abstract: Nonlinear dynamics of a high speed unbalanced rigid rotor drop onto rigid sliding-bearings is investigated. A theoretical formulation is proposed and solved numerically to examine the dynamics of the rotor: The orbits of the rotor in backup bearings after the rotor drop, velocities and power loss during the sliding-whirling are presented for various initial conditions and system parameters. The contribution of parameter such as air-gap, coefficient of friction, coefficient of restitution, and unbalance to the rotor drop dynamics is examined as well.

Key words: Active magnetic bearings, Drop, Dynamics, Nonlinear, Rotor Unbalance