| 摘要 |
PURPOSE:To improve the precision of the dimensions of a magnet and thereby increase productivity by a method wherein a plastic binder magnet is formed monolithically, by injection molding, on a rotor core made of plastic. CONSTITUTION:A rotor core is constituted by a central shaft member 2 having pivots 2a and 2b at the upper and lower ends, a flange member 3 provided in the lower part of the central shaft member 2, and a rotor pinion 4, all of which are molded monolithically from thermoplastic resin such as polyacetals. A plastic binder magnet which is formed by mixing ferrite in nylon, for instance, and to which injection molding can be applied is formed on the central shaft member 2 above the flange member 3 of the rotor core 1 by the injection molding, and thereby a magnet 5 is formed in one body with the rotor core 1. |
