| 摘要 |
PROBLEM TO BE SOLVED: To install a variable torque canceling permanent magnet rotor coaxially with a permanent magnet rotor so as to reduce torque ripples occurring in a motor body in a permanent magnet field brushless motor having the permanent magnet rotor. SOLUTION: The permanent magnet field brushless motor is composed of the permanent magnet rotor of a rotor magnetic pole number 2P (P represents a magnetic pole pair number) and a stator having an M-phase armature winding. The variable torque canceling permanent magnet rotor of a magnetic pole number 4PM is installed coaxially with the permanent magnet rotor. The center of a specific magnetic pole of the permanent magnet rotor and that of the closest magnetic pole in a canceling permanent magnet rotor having the same pole as that of the specific magnetic pole are shifted by±(180±20)°/2PM. Small teeth are provided to a stator part corresponding to a magnetic pole pitch of the canceling permanent magnet rotor. The canceling permanent magnet rotor of a magnetic pole number 4PM may be replaced with a reluctance type rotor having the small teeth of a teeth number 2PM. COPYRIGHT: (C)2007,JPO&INPIT |
