| 摘要 |
PURPOSE:To reduce the irregular rotation of a motor by forming the opposed side of magnets of a pole portion in circular shape, and forming the air gap magnetic flux density of the ends of multipolarized ferrite magnets in an approximate sinusoidal wave. CONSTITUTION:The sectional shape of a ringlike axial anisotropic ferrite magnet 4 is formed in a circular shape. When a magnetizing coil 5 is energized, since the section of a pole portion is formed in a circular shape, the end of the pole portion is magnetically saturated. As a result, since relatively large lines of magnetic flux pass the interior of the magnet 4, an air gap magnetic flux density distribution becomes a sinusoidal shape. Thus, the irregular rotation of the motor when the motor rotates at a low speed can be reduced. |
