Patent ID: 7167345
Filing Date: 2007-01-23
Classification: B82Y,G01D,G01R,H01F,Y10T

Abstract:
1. The magnet array including plural permanent magnets, each having an approximately rectangular parallelepiped shape and having a sectional shape, perpendicular to one central axis of the rectangular parallelepiped, which is approximately square, and each having poles formed at both edge faces, one of which has the approximately square shape perpendicular to the central axis of the rectangular parallelepiped and a thin plate-like yoke formed of a magnetic material; wherein the plural permanent magnets are arranged in such a manner that each center of gravity of the edge faces having the approximately square shape is matched with a lattice point of a tetragonal lattice, a certain side of sides forming one of the edge faces of the plural permanent magnets disposed in a certain row of the tetragonal lattice and a certain side of sides forming one of the edge faces of the other plural permanent magnets disposed in the same row of the tetragonal lattice is in a same straight line, all the edge faces having the square shapes of the permanent magnets are placed in an approximately same single plane, and any two of the polarities of the magnetic poles of the permanent magnets disposed adjacent each other and spaced by the shortest route are different each other; and the yoke comprises plural through holes each of which has a shape which is the approximately same as the sectional shape which is approximately square and the holes being arranged at the positions where the permanent magnets are disposed, and the yoke being arranged in such a manner that the same single plane in which all the edge faces of the permanent magnets are placed is disposed between an upper surface and a lower surface of the yoke when the permanent magnets are inserted into the through holes, wherein the yoke has through openings serving as air gaps formed between the through holes that are adjacent each other and that are spaced by a shortest route.