Influence of Elastic Buffer on Rotor Drop Dynamic Response

In an active magnetic bearing (AMB) system, the rolling-element catcher bearings (CBs) are indispensable to protect the magnetic bearing rotor and stator. This paper introduces a new structure with elastic buffers located on the rotor. And numerical analysis for a rotor drop on CBs using detailed CB model on the basis of Hertz contact theory are presented. The backward whirl of the rotor, which may lead to the destructive damage of the machinery, has been analytically predicted when the system without elastic buffers. The displacements of the sleeve and rotor and also the contact force between the sleeve and the inner-race of the back-up bearing have been computed for various buffer stiffness and damping parameters. Furthermore, elastic buffer design guides based on the simulation results are presented.