Patent ID: 7049721

Claim:
An eccentric rotor rotatably about an axis of rotation and having a first side and a second side, comprising: a printed wiring board, two wound air-cored coils arranged juxtaposed to the printed wiring board, a weight, and a resin structure integrally molding said printed wiring board, said air cored coils and said weight into a disk-like shape; said printing board having a first side and a plurality of commutator segments on said first side; said weight having a first side which is exposed at the first side of the rotor together with the first side of the printed wiring board and a second side of the weight which is exposed at the second side of the rotor together with the air cored coils; said resin structure having an outer peripheral portion having a circular-arc periphery about the axis of rotation; and said outer peripheral portion of said resin structure having a projection extending in an axial direction from the first side of the rotor and having one part superimposed with the first side of the weight and another part superimposed with the first side of the printed wiring board.