| 摘要 |
PURPOSE:To achieve a stable control of the output of a Hall element as a rotation sensor by converting it into a voltage after a wave thereof is shaped at a rotation detecting section while the rotation is set at a low speed. CONSTITUTION:As a rotor 2 of a motor M rotates, a magnet 9 and plates 10 and 11 fastened on a shaft 3 turns so that air is sucked through a hole 4a with the fan 2a of a rotor 2 and blades P10 and P11 of the plates 10 and 11 and exhausted through a side hole 4b. Cooled through the blades P10 and P11, the plates 10 and 11 can reduce the rise in the temperature of the magnet 9 caused by the motor M thereby preventing the lowering of a magnetic force. A coil 5 cooled by air of the blade P10 and P11 can reduce the rise in the temperature of the motor M. As the blades P10 and P11 of the plates 10 and 11 on the magnet 9 can be provided in plurality radially on the circumference for lowering the rise in the temperature of the motor M, the motor can be produced at a low cost. |
