Principle and parameter design for an innovated radial-axial hybrid magnetic bearing

In the paper, an innovated radial-axial hybrid magnetic bearing (HMB) is proposed, which is driven by a 2-phase AC power inverter in radial directions and a DC amplifier in axial direction respectively. The axial and radial biased magnetic fluxes are provided by a common radial polarized permanent magnet ring, and the axial and radial control magnetic fluxes are provided by the inner and outer two-layer coils, respectively. The configuration and the principle producing magnetic suspension forces of the radial-axial HMB are introduced. The flux path is calculated by using the method of equivalent magnetic circuits, the mathematics models of the axial and radial magnetic suspension forces are deduced. The methods on parameter design and calculation of the innovated magnetic bearing are presented in detail. The experiment prototypepsilas parameters of the innovated radial-axial HMB are given. The feasibility and the correctness of the theoretical methods for the configuration, magnetic path and maximum loads capacity of the radial-axial HMB are verified by 3D-FEM analysis.