Dynamic Responses of Rotor Drops onto Double-Decker Catcher Bearing

In an active magnetic bearing (AMB) system, the catcher bearings (CBs) are indispensable to protect the rotor and stator in case the magnetic bearings fail. Most of the former researches associated with CBs are mainly focused on the dynamic responses of the rotor drops onto traditional single-decker catcher bearings (SDCBs). Based on the analysis of the disadvantages of SDCBs, a new type of double-decker catcher bearings (DDCBs) is proposed to enhance the CB work performance in AMB system. Detailed simulation models containing rigid rotor model, contact model between rotor and inner race, DDCB model as well as SDCB model after rotor drop are established using Multi-body dynamics simulation software MSC.ADAMS. Then, using those established models the dynamic responses of rotor drops onto DDCBs and SDCBs are respectively simulated. The rotor orbits, contact forces and spin speeds of various parts after AMB failure are mainly analyzed. The simulation result shows that DDCBs can effectively improve reduce the following vibrations and impacts. Finally, rotor drop experiments choosing different types of CBs are carried out on the established AMB test bench. Rotor orbits and the rotating speeds of both inner race and intermediate races after rotor drop are synchronously measured. The experiment results verify the advantages of DDCB and the correctness of simulation analysis. The studies provide certain theoretical and experimental references for the application of DDCBs in AMB system.