PERMANENT MAGNET SYNCHRONOUS MOTOR AND ITS DRIVING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a permanent magnet synchronous motor by which vibrations and noises as a whole can be reduced by reducing axial vibrations. SOLUTION: The axial dimension Lr of a rotor iron core 12 with a permanent magnet 13 mounted thereon and that of Ls on the inner diameter side of a stator iron core 5 are made of a structure with some difference. Either of the stator iron core 5 and the rotor iron core 12 having a shorter axial dimension is installed in the longer axial dimension of either of the stator iron core 5 and the rotor iron core 12. By the constitution, magnetic attraction force generated by the axial deviation of the magnetic center between both iron cores can be suppressed small. The axial vibrations and noises caused by the magnetic attraction force, which is changed by the rotation direction, can be reduced. COPYRIGHT: (C)2005,JPO&NCIPI