Dynamic analysis of magnetic bearing rotor dropping on radial and axial integrated auxiliary bearing

摘要

A radial and axial integrated auxiliary bearing (RAIAB) which can eliminate all radial and axial protective clearances between the rotor and auxiliary bearing after the rotor dropping is proposed and proved to be feasible. For horizontally placed magnetic suspension rotor, detailed dynamic models of rotor dropping onto RAIAB with 5 degrees of freedom (DOF) is established, including the 5-DOF rotor dynamic model, the impact model of cone between rotor and neck bush, and the dynamic model of a pair of back-to-back mounted angular contact ball bearings. The situation when the 5-DOF AMB rotor drops to RAIAB at 30 000rpm is simulated and calculated. Meanwhile, the movement characteristics of the rotor and auxiliary bearing, and radial and axial impact force characteristics acted on rotor, as well as the internal force generated in auxiliary bearing are analyzed in detail. Furthermore, 5-DOF AMB test rig with RAIABs installed at both sides was built, and all DOF drop tests of the rotor were carried out. The results show that the RAIAB can immediately eliminate all the protective clearances after the rotor drops, and then completely and stably sustain the rotor to continue rotating around its original center in both radial and axial directions. (C) 2019 Elsevier Ltd. All rights reserved.