| 摘要 |
PROBLEM TO BE SOLVED: To provide a stepping motor capable of reducing the vibration and noise of the motor by decreasing cogging torque that is generated at motor driving, with the shape of a yoke optimized to provide excellent torque characteristics. SOLUTION: The stepping motor comprises a cylindrical magnet 112 where the N-pole and the S-pole are alternately magnetized in a circumferential direction. A rotor is composed of the rotating shaft of a specified length which is integrally provided with the magnet 112 in the middle of a length, and at least one yoke for the engagement of rectangular upper and lower pole teeth on the inner peripheral surface facing the outer peripheral surface of the magnet 112 at specified intervals. It also comprises a stator composed of a coil wound on a bobbin provided on the inner surface of the yoke, two large square magnetic poles 112a of which the magnetic pole of the magnet 112 is formed at an opposite angle facing each other with the center of the rotation of the magnet 112 as a reference so that, with the upper and lower pole teeth of the yoke arranged in the circumferential direction at constant intervals, repulsion and attraction generated between each magnetic pole of the magnet 112 and the upper and lower pole teeth of the yoke occur unevenly, and a plurality of small square magnetic poles 112b formed in the circumferential direction between the large square magnetic poles 112a at constant intervals. COPYRIGHT: (C)2006,JPO&NCIPI
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