| 摘要 |
PURPOSE:To improve the torque ripple of a brushless motor by providing the first, second auxiliary coil groups of one or more auxiliary coils at a stator, and cancelling the drop of torque produced at the drive coil by the peak of the torque generated at the drive coil. CONSTITUTION:Auxiliary coils 10A, 10A are respectively provided corresponding to the phases of drive coils. The auxiliary coil 10A of phase A is provided at an electric angle 5/4pi clockwise from the center l of the drive coil 4A1, the coil 10B of phase B is provided at an electric angle 9/4pi counterclockwise from the center l of the coil 4A1, and the opening angle of the auxiliary coils is pi/4 of electric angle. The coils 10A, 10B of the phases A, B are energized at an electric angle of pi by the output signal of a magnetic sensitive element 9 which detects the rotating position of a drive magnet 3, thereby reducing the torque ripple. |
