Principles and Test Result of Novel Full Passive Magnetic Levitation Motor with Diamagnetic Disk

This paper proposes a novel full passive magnetic levitation motor without active magnetic suspension. It has a magnetic levitation unit and a motor unit. The Halbach array permanent magnets and a pyrolytic graphite (PG) disk realize the full passive magnetic levitation. The rotational motor torque is generated by a coreless motor. The axial and radial stable forces are calculated by the diamagnetic equation based with magnetic field distribution given by the 3-D FEM analysis. In experiment, the static levitation force and axial vibrations are measured and speed control test is conducted as high as 4000 r/min.