| 摘要 |
PURPOSE:To compose in small size and weight inexpensively by providing a spiral spring secured to the rotational shaft of a rotor and a body, energizing an armature coil to alternately excite two salient poles synchronously with the free vibration of the rotor. CONSTITUTION:A soft steel plate is punched and pressed to mount an armature coil 6 on U-shaped yoke 5, salient poles 5a, 5b are provided at the open ends of a yoke magnetic path, and opposed to the inner periphery of a ferrite magnet 4. A rotational shaft 1 is supported by a bearing 8 secured to a plastic frame 7. The magnet 4 is magnetized at N- and S-poles at the angle of 180 deg.. A metal spiral spring 10 is secured at the central end to the shaft 1 and at the outer peripheral end to a metal piece 11. A pyroelectric infrared photoreceptor 2 is bonded to the plastic mold (flat plate) 1 to become a rotor, and a fan 3 is provided. Thus, the coil 6 is energized by the frequency output synchronized with the free vibration of the rotor, the pole 5 is synchronized to be alternately excited to be reciprocatingly vibrated. |
