| 摘要 |
PROBLEM TO BE SOLVED: To increase precision of the angular rotation of a small-sized motor which has a plurality of rare-earth bond magnets as components and to reduce vibration noise. SOLUTION: This small-sized motor has two cylindrical rare-earth bond magnets 6, 7 arranged at intervals in the axial direction of its rotor 5. At manufacturing rare-earth bond magnets, a means of increasing the dimensional shape precision of the formations is contrived. Along with it, their magnetizing method is devised, and a magnetization variation is suppressed small, and the difference between the magnetic flux quantities of the magnets 6, 7 is made to within 1.5%. Consequently, attractive and repulsive forces between the rotor 5 and yokes 3, 4 are prevented from varying in the axial direction, and its angle-of- rotation precision enhances. Moreover, resultant higher-harmonic waves of two phases reduce, rotation of the rotor 5 becomes smooth, and vibration noise are reduced. |
