Estimation of Rotating Torque in a Five-Axis Passively Stabilized Bearingless Graphite Motor with Diamagnetic Rotor

Five-axis passively stabilized bearingless motors with diamagnetic materials have notable advantages as they do not require displacement sensors and suspension powers for static magnetic suspension. A diamagnetic pyrolytic graphite rotor is passively levitated and actively rotated. In previous studies, the principle of passive levitation force generation has been proposed and experimentally verified. In this paper, the torque generation principle of the diamagnetic bearingless motor is derived, and the rotating torque is estimated in deceleration and acceleration tests.