| 摘要 |
PURPOSE:To suppress torque ripple easily by providing a stator in which a plurality of coils having effective pitch of 180 deg. electric angle, and a rotor arranged, on the circumference thereof, with a plurality of permanent magnets having trapezoidal flat part magnetized at 60 deg.. CONSTITUTION:A plurality (eight, in the drawing) of permanent magnets 3, alternately magnetized with multi-poles, are arranged on the circumference of a disc 2' thus forming a rotor 2. The permanent magnet 3 is magnetized such that the flux distribution at the flat part will be trapezoidal at electrical angle of 60 deg.. A plurality (six, in the drawing) of air-core coils X1, X2-Z1, Z2, interlinking with the permanent magnets, are arranged thus forming a stator 4. Effective pitch of each coil is set at 180 deg. electric angle, and the coils X1, X2-Z1, Z2 are connected in series or parallel into three-phase coils. Power is fed sequentially from a drive circuit (not shown) to the three-phase coils based on output signals from position detecting elements A-C, arranged in the centers of the coils X1-Z1, thus rotating the rotor 2 around a shaft 1. |
