Analytical Modeling of Permanent Magnet Biased Axial Magnetic Bearing With Multiple Air Gaps

This paper proposes a permanent magnet (PM) biased axial magnetic bearing (MB) with multiple air gaps. However, the inherent complex structure makes finite-element analysis (FEA) very time-consuming. For the sake of simplifying the analysis, an equivalent magnetic circuit model together with the conformal mapping method and Laplace's equation is developed. The conformal mapping method is employed to obtain the flux distributions in rectangular air gaps by accounting fringing effect, while the Laplace's equation is used to predict the leakage flux surrounding PM rings. The developed analytical model is validated by FEA. Consequently, the design parameters in the axial MB are analytically determined.