MULTISTAGE, LONG AND MULTIPOLE POLARIZING CYLINDRICAL MAGNET ROTOR AND PERMANENT MAGNET MOTOR

摘要

PROBLEM TO BE SOLVED: To prevent the occurrence of torque irregularity by stacking cylindrical magnets manufactured by a vertical magnetic field forming method and oriented in one direction perpendicular to a cylindrical shaft in a multi-stage in an axial direction for formation of a long cylindrical magnet in multipole-polarizing its outer peripheral surface so as to serve as a rotor of a permanent magnet motor.;SOLUTION: A cylindrical magnet whose orientation is turned 90° so as to have one-way anisotropy is 6-pole polarized to obtain large magnetic flux density at oriented A and D poles, and the magnetic flux density becomes small at a part in the perpendicular direction to the orientation of B, C, E, and F poles. On the other hand, when the one-way anisotropy cylindrical magnet is sliced, divided into two in a cylindrical- axial direction, turned, stacked in two stages, and polarized, the total amount of magnetic flux increase at the A, D poles and decreases at the B, C, E, and F poles. The cylindrical magnet manufactured by a vertical magnetic field forming method and oriented in one direction perpendicular to the axial direction is axially stacked in two stages and multipole-polarized. It is thus possible to reduce variations in the amount of magnetic field for suppression of torque irregularity.;COPYRIGHT: (C)2000,JPO