PASSIVE AND ACTIVE MAGNETIC BEARING BY USING THE LORENTZ FORCE

摘要

The present invention relates to a passive and active magnetic bearing using the Lorentz force, which consists of a rotor with a permanent magnet at its center and several coils which are located at an outside axial air gap of the rotor and fixed to a stator. The air gap is designed to be narrow at the center and gets increasingly wider towards the radial direction so that flux density by the permanent magnet varies according to the radial position. For the passive function, a DC current flows in all coils so that the direction of the generated Lorenz forces is outside in the air gap. It makes it Possible that, when the rotor moves from the predesignated Position, a restoring force is generated which steadily levitates the rotor. While, it can also perform as an active magnetic bearing, if the currents are controlled depending on the location of the rotor.