关键词: 磁悬浮轴承, 保护轴承, 转子跌落, 轴承损伤, 失效机理

Abstract: For the national key R&D program “high-speed precision suspension bearing”, the requirements for the drop capacity of TDBs were: rotor mass ≥3000 kg, drop speed ≥3000 r/min, and successful drops ≥10 times. Based on this, the research and development of TDBs drop failure mechanism were carried out. Two hybrid TDBs with ceramic balls suitable for drop conditions were proposed: full complement ball without cage scheme and non-full complement ball with cage scheme. A rotor drop simulation model was built including dynamics and thermal. The force and heating processes of the drop processes were simulated. The effectiveness of the simulation model was verified by mounting the TDBs in the test bench for experiments. TDBs without cage are found to have failed severely. The damages of the failed bearing are detected, and it is observed that due to the large friction coefficient between the rolling elements, the rolling elements are seized up, resulting in continuous dry friction between the rolling elements and the raceways, and between the inner ring and the rotor, and serious burns and wear of the inner rings.

Key words: active magnetic bearing, touchdown bearing(TDB), rotor drop, bearing damage, failure mechanism