A New Structure for Permanent-Magnet-Biased Axial Hybrid Magnetic Bearings

• Published in: IEEE transactions on magnetics Vol. 45; no. 12; pp. 5319 - 5325
• Main Authors: Jiancheng, Fang, Jinji, Sun, Yanliang, Xu, Xi, Wang
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.12.2009; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Angular momentum; Assembly systems; Axial hybrid magnetic bearing; Cross-disciplinary physics: materials science; rheology; Design engineering; equivalent magnetic circuit; Exact sciences and technology; FEM analysis; Finite element analysis; Finite element method; Finite element methods; Flux; Flywheels; Housing; Magnetic analysis; Magnetic bearings; Magnetic circuits; Magnetic levitation; Magnetism; Materials science; Mathematical models; Other topics in materials science; permanent magnet biased; Permanent magnets; Physics; Power system modeling; Prototypes; reaction flywheel; Reliability theory; Finite element method; permanent magnet biased; FEM analysis; reaction flywheel; Axial hybrid magnetic bearing; equivalent magnetic circuit; Permanent magnets; Magnetic circuits; Magnetic properties; Equivalent circuits
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2009.2024687

We propose a new structure for a permanent-magnet-biased axial hybrid magnetic bearing. Starting with the inner air gap and the outer air gap of conventional axial magnetic bearings, we first construct a novel air gap between the permanent magnet and the outer housing, which we call the second air gap, separating the bias flux paths from the control flux paths. As a result, the control flux paths will have lower reluctance, and the power loss of the axial magnetic bearing will be lower. Next, we modeled this axial hybrid magnetic bearing and analyzed it using the equivalent magnetic circuit method, 2-D finite element method (FEM), and 3-D FEM. We have designed and assembled an axial hybrid magnetic bearing prototype for a reaction flywheel system with angular momentum of 15 Nmiddotmmiddots at a speed of 5000 r/min. The theoretical analysis and the prototype experiments show such advantages as simple structure, good force current and force displacement, and high operating reliability.