| 摘要 |
PURPOSE:To reduce the cost of a frequency generator and to enhance the reliability by forming many projections on the end perpendicular to a drive magnetic field of a drive permanent magnet for the generator in the axial direction of a rotational shaft. CONSTITUTION:A transistor motor supports a rotational shaft 24 through bearings 22, 23 to a bracket 21, and secures a drive permanent magnet 27 through a spacer 25 and a magnetic rotor 26. Projections 28 are formed on the end of the magnet 27, a generating coil 30 is opposed through the prescribed air gap on the printed board 29 thereto, and secured to a magnetic frame 31. A magnetic circuit is formed through the magnet 27, projections 28, magnetic frame 31 and the magnet 27. Thus, dense and rough magnetic fluxes are generated at the projections 28 by magnetizing the magnet 27, and when the magnet 27 is rotated, the rough and dense magnetic fluxes cross the coil 30 to generate a frequency proportional to the rotating speed. |
