摘要 |
PURPOSE:To increase the brake retaining force of a step motor by forming the magnetic flux distribution of a magnet forming a rotor in a rectangular wave responsive to the width of the magnetic pole teeth of a stator, thereby increasing a shaft torque, reducing the size and hence GD<2>. CONSTITUTION:Magnets 15 of the number corresponding to the teeth of the exciting magnetic poles of a stator are arranged alternately at the N- and S-poles on the outer periphery of a rotor 5. The magnets 15 are so magnetized uniformly that the magnetic flux distribution of the magnets 15 becomes, as illustrated by solid lines or one dot chain lines, rectangular waveform responsive to the width of the teeth of the exciting magnetic poles. Thus, the shaft torque can be increased with the same shape, the size can be reduced with the same shaft torque, thereby increasing the brake retaining force. |