Eccentric rotor and a vibrating motor using the same

摘要

An eccentric rotor wherein a printed wiring board in which commutator segments are formed at a first surface, two wound air-cored coils arranged with a prescribed arrangement angle about the shaft as a center at the second surface of the printed wiring board, and a weight are integrally molded into a disk-like shape with a resin by injection molding. The weight comprises a first surface of the weight which is exposed at the side surface of the rotor together with the first surface of the printed wiring board and a second surface of the weight which is exposed at the other surface of the rotor together with the wound air-cored coil. The resin which integrates the aforementioned components and forms an outer peripheral resin portion having a circular-arc periphery about the shaft as a center. The outer contours of the weight and printed wiring board are so formed as to assume positions separated from the outer periphery inwardly in a circular-arc portion. In the circular-arc portion at the outer periphery of the rotor, a continuous circular-arc protrusion covering the first surface of the weight and the first surface of the printed wiring board at one surface side of the rotor is formed integrally with the outer peripheral resin portion.