Patent ID: 8274182
Filing Date: 2012-09-25
Classification: H02K

Abstract:
1. A linear motor comprising: a stator having a plurality of field poles arranged linearly with opposing polarities thereof arranged in an alternating manner; and a rotor having an armature core with a plurality of teeth that faces a pole face of the field poles with a predetermined gap therebetween, and coils wound around the teeth, wherein the stator and the rotor are supported in a slidable manner, a direction perpendicular to a sliding direction of the rotor and in parallel with the pole face is defined as a stacking direction, a head of each of the teeth has an extended portion that is extended in both a first and a second, opposite direction parallel to the sliding direction, at least heads of the teeth arranged at both ends of the armature core along the sliding direction is divided into a plurality of areas along the stacking direction, and at least one of extended portions in the first direction is extended by a different length along the sliding direction than an extended portion in the second direction on a first tooth, a second tooth adjacent to the first tooth in the stacking direction has an extended portion in the first direction with a different length along the sliding direction than an extended portion in the second direction, a first stepwise skew angle between the first and second tooth is equal to (A−C)×180°/τ and a second stepwise skew angle between the first and second tooth is equal to (B−D)×180°/τ, where A is a length of the extended portion of the first tooth in the first direction, B is a length of the extended portion of the first tooth in the second direction, C is a length of the extended portion of the second tooth in the first direction, D is a length of the extended portion of the second tooth in the second direction, and τ is the distance between the field poles of the stator, and the first stepwise skew angle and the second stepwise skew angle are non-zero and equal to each other.