To increase an output torque at least in the direction of normal rotation with simple structure, in a brushless motor or a motor with a brush.
Since a control means 47 sets a phase difference between the heterogeneous poles of a rotor 43 and a stator 45, which attract each other when controlling the rotating magnetic fields of the stator 45, to 90° plus a predetermined angle by offsetting the mounting position of the magnetic pole sensor 46 for the brushless motor by a predetermined angle in the direction of reversal of a motor shaft 41, it can enlarge the output torque at normal rotation of the motor shaft 41 more than the output torque at reversal. At this time, it is enough to offset the mounting position of the magnetic pole sensor 46 by a predetermined angle without changing a control program for controlling the rotating magnetic field of the stator 45 by the control means 47 at all, so it is feasible at extremely low cost. For the motor with a brush, the same action effect can be achieved by offsetting the mounting position of the brush by a predetermined angle in the direction of reversal of the motor shaft 41.
SUNADA SATORU
Kazuaki Niki
Nude Shima Shinji