Patent ID: 6705776
Filing Date: 2004-03-16
Classification: G03B,H02K

Abstract:
An electromagnetic actuator characterized in that it comprises:a magnetizing coil; a rotor that is magnetized with different polarities and rotates by a predetermined angle range between an initial position taken when an electric current is stopped and a maximum rotational position where the rotor rotates angularly to the maximum when an electric current is applied, thereby outputting a driving force; and a first magnetic pole part and a second magnetic pole part that are disposed so as to face an outer circumferential surface of the rotor and that generate mutually different magnetic poles through a magnetic path when an electric current is passed through the coil; wherein the rotor has a projection that is magnetized with one of the different polarities and that projects outward in its radial direction, and an auxiliary magnetic pole piece is provided in the vicinity of the first magnetic pole part, the auxiliary magnetic pole piece being disposed so as to be close to or be in contact with the projection when the rotor is located at the initial position, and the auxiliary magnetic pole piece generating the same magnetic pole as the first magnetic pole part when a current is applied.