| 摘要 |
PURPOSE:To eliminate a reinforcing band and to enhance the strength with respect to a centrifugal force by providing a groove on the outer periphery of a rotational shaft, engaging holes which are opened with a plurality of windows, and then filling and molding magnetic powder in the windows. CONSTITUTION:Holding grooves 8 of a core 7 are formed axially on the outer periphery of a rotational shaft 6 in the shape that the openings are narrower than at the inside such as in a dovetail shape. Further, a holder 9 in which windows 9a for containing core 7 in the cylindrical shape that outer peripheral sides 9b are projected inwardly at four positions and the holes are narrower than at the inside is formed of a nonmagnetic material suh as aluminum, and engaged with the outer periphery of the shaft 6. Then, magnetic powder of ferrite or rare earth elements is filled in the windows 9a, pressure molded and baked in a furnace, and the core 7 is then magnetized as a rotor with a permanent magnet. |
