Stability Analysis of a New Passive PMs Bearing

In this paper a new Permanent Magnets (PMs) bearing is presented. The device is composed of a rotor capable to levitate at a short distance from a dedicated stator. The magnetic suspension is achieved by proper configurations of PMs arranged on both the stator and the rotor. The device is characterized by intrinsic instability and passive stabilization is attempted exploiting eddy currents on a conducting sheet surrounding the stator magnets. The system has been simulated by means of a dedicated numerical tool capable to take into account the effects of the magneto-mechanical coupling. In particular, the coupled problem has been integrated by means of a prediction-correction nested scheme. The simulation activity has produced some interesting results, that are here extensively discussed. More specifically, it has been shown that the stability with respect to the center of mass translation can be passively obtained, if the rotations are actively prevented. An idea of an active stabilizing system for the rotations, exploiting the results of the simulation is finally briefly described.