A Theoretical Investigation of Hybrid Foil-Magnetic Bearings on Operation Mode and Load Sharing Strategy

Abstract To guide the conceptual design of hybrid foil-magnetic bearings (HFMBs), this paper presents a theoretical investigation on operation mode and load sharing strategy. According to the inherent characteristics of GFBs and AMBs, seven possible work scopes are discussed to understand the operation mode of HFMBs. A numerical model coupling the calculations of the film pressure in GFBs and the magnetic forces in AMBs is conducted to predict the performance of HFMBs. The deflection of top foil and bumps is also included in the prediction model. The analysis, which is conducted for static and dynamic performance of HFMBs within three representative work scopes by varying the load sharing, uncovers the effects of the operation mode and load sharing strategy on bearing behavior. Results show that HFMBs performance including the supporting stiffness and stability can be obviously enhanced by adjusting the operating mode and load sharing strategy.