Patent ID: 6949846
Filing Date: 2005-09-27
Classification: H02K

Abstract:
1. A linear motor which has a stator and a movable element constructed to reciprocate linearly relative to said stator comprising: one or more magnetic pole rows provided at one of said stator and said movable element and constituted by juxtaposedly arranging a plurality of permanent magnets, and an armature provided at the other of said stator and said movable element and including: wherein each of said magnetic pole surfaces of two pole teeth located at both ends of a pole tooth row constituted by said plurality of the pole teeth comprises a curved surface curved such that a gap between said magnetic pole row and said curved surface increases with increasing distance from other pole teeth adjacent thereto; and wherein said curved surface is formed so as to satisfy a relationship of 0.38≦Lt/R≦0.65, in which R is said radius of said arc, and Lt is a length between a lower end of said curved surface, and an intersection of a virtual line passing through said lower end of said curved surface and extending in parallel to said magnetic pole row and a virtual perpendicular passing through an upper end of said curved surface and orthogonally crossing said virtual line; and wherein a contour of said curved surface, as seen from one side of said laminating direction of said electromagnetic steel plates, has a shape of an arc and the radius of said arc is defined so as to satisfy a relationship of 1≦R/ an angle α between a virtual line extending in parallel to said magnetic pole row and a tangent line passing through said lower end of said curved surface is 0°.