Patent ID: 7884509
Filing Date: 2011-02-08
Classification: H02K

Abstract:
1. A linear motor comprising: a movable magnet yoke taking a hollow shape; a plurality of magnet constructs attached to a circumferential surface of the magnet yoke at an equiangular distance; coil yokes, wherein the magnet yoke is movable relative to the coil yokes; and a plurality of coils attached respectively to the coil yokes and arranged to respectively face the plurality of magnet constructs; and wherein: each of the magnet constructs comprises respective pairs of the magnet members attached to the circumferential surface form first and second rows spaced from each other in the moving direction of the magnet yoke; each magnet member in the first row is arranged to be opposite in polarity of magnet pole to each of the magnet members next thereto in the circumferential direction, and the poles of each magnet member in the first row are arranged such that lines of magnetic force extend through the magnet yoke between each of the circumferentially adjacent magnet members in the first row and the magnet members next thereto in the circumferential direction; and each magnet member in the second row is arranged to be also opposite in polarity of magnet pole to each of the magnet members next thereto in the circumferential direction, and the poles of each magnet member in the second row are arranged such that lines of magnetic force extend through the magnet yoke between each of the circumferentially adjacent magnet members in the second row and the magnet members next thereto in the circumferential direction.