Patent ID: 7476990
Filing Date: 2009-01-13
Classification: H01F,H02K

Abstract:
1. A linear actuator comprising: a stator; a movable element having an iron member at which reciprocates with respect to the stator; a first pair of permanent magnets fixed to the stator in having the the permanent magnets arranged side by side in the direction of reciprocation of the movable element while being opposed to the iron member, magnetic poles thereof are arranged in a direction perpendicular to the direction of reciprocation, and orientations of the magnetic poles thereof differ from each other; a second pair of permanent magnets fixed to the stator in such a manner that a position thereof in the direction of reciprocation coincides with the first pair of permanent magnets, the permanent magnets are arranged side by side in the direction of reciprocation while being opposed to the iron member, magnetic poles thereof are arranged in a direction perpendicular to the direction of reciprocation, and orientations of the magnetic poles thereof differ from each other; and a coil fixed to the stator, wherein the magnetic pole which faces the iron member of one of the first pair of permanent magnets and the magnetic pole which faces the iron member of one of the second pair of permanent magnets that is disposed at the same position in the direction of reciprocation as the one of the first pair of permanent magnets differ from each other.