Permanent Magnet Biased Axial-radial Magnetic Bearing Design Based on the Accurate Magnetic Circuit

Permanent magnet biased axial-radial magnetic bearing (ARMB) can realize axial and radial suspension simultaneously. It has a compact configuration with the volume and weight reduced. However, its magnetic field distribution is quite complicated, its bias and control magnetic field are coupled. In order to design the magnetic bearing accurately, this paper divides the leakage and soft magnetic material routes according to the 2D FE simulation, establishes the accurate magnetic circuit including the leakage and soft magnetic material reluctance. The circuit can be used to observe the flux distribution in each route, verify and regulate the magnetic bearing structure parameter, so the FE computation efforts of the basic structure parameter are significantly reduced. An experimental sample was designed, 3D FE simulation and experiments were processed to test the prototype. The results confirm that the design method is reasonable and correct.