Patent ID: 6703743
Filing Date: 2004-03-09
Classification: H02K

Abstract:
A permanent magnet electrical machine used as a motor or as a generator, comprising:a movable member having a permanent magnet; and a stator having a coil which generates an alternating magnetic field to drive the movable member, the alternating magnetic field applying a repulsive force on the permanent magnet, wherein the permanent magnet is divided with one or more substantially flat faces into a plurality of sections in order to suppress the flow of an eddy current generated by high frequency components in the alternating magnetic field, said one or more substantially flat faces being substantially perpendicular to the direction of motion of the permanent magnet, and wherein the width of each of the plurality of sections of the permanent magnet is set to decrease with an increase in the rate of change in the flux density in applied to each of the plurality of sections during fixed-speed operation of the moveable member.