A Novel Hybrid Axial Magnetic Bearing that Produces a Unidirectional Electromagnetic Force

This paper proposed a novel hybrid axial magnetic bearing (HAMB) for a vertical system, which can produce a unidirectional magnetic force. The characteristics of the new HAMB are analyzed. When the rotor is suspended in the equilibrium position, the bias force offsets the gravity of the rotor and the current is zero, which can reduce the copper loss. According to the magnetic field distribution, an equivalent magnetic circuit is established. Based on the analytical model, the curve of force-current, curve of force-displacement, and bearing capacity are calculated. The results of analytical are consistent with the ones of the finite element method (FEM).