Patent ID: 7710225

Claim:
An actuator comprising: an exciting coil; a stator having a first yoke part, which is formed on the one end side of said exciting coil, and a second yoke part, which is formed on the other side of said exciting coil, so as to cover said exciting coil; and a movable element being provided in a center part of said exciting coil and capable of reciprocally moving in the axial direction, wherein a magnetic circuit is formed between the first and second yoke parts and said movable element by energization, and a magnetic force acts on said movable element, wherein an inclined groove is formed in the peripheral surface on the one end side of the movable element and continuously inclined from the radial one end side of the movable element to the other end side thereof, a facing area of the peripheral surface of the movable element, on which the magnetic flux acting surface is formed, is gradually reduced in the axial direction, and the movable element in the center part of the exciting coil is attracted, by energizing the exciting coil, toward a guide surface on the radial one end side, in which magnetic resistance is lower, and slides thereon.