Patent ID: 8456055

Claim:
A magnetic pole core for a motor, comprising: a plurality of core blocks united annularly, wherein each of the core blocks has an arm portion, and a yoke portion extending in a circumferential direction at an end of the arm portion, and at least the yoke portion is configured such that a plurality of core segments are stacked in multiple levels in an axial direction of a rotative shaft of the motor or in a radial direction, each of the core blocks having engaging portions formed at respective opposite ends of the yoke portion and adapted to connect the core block to adjacent core blocks, wherein in at least one of the core segments stacked in multiple levels, each of the engaging portions has a protrusion extending in the circumferential direction from a corresponding one of the opposite ends of the yoke portion, and a recess juxtaposed to the protrusion in the radial direction or the axial direction and adapted to receive the protrusion of an adjacent core block, and, in at least another one of the core segments stacked in multiple levels, each of the engaging portions has the protrusion and the recess provided in positionally reversed relation with those of the one of the core segments with respect to the radial direction or the axial direction, wherein each of the protrusions extending in the circumferential direction from the yoke portion has an engaging convexity which is formed at a distal end portion of the protrusion through increase in thickness of the distal end portion as compared with a root portion of the protrusion, thereby forming, on a side toward the root portion, an engaging concavity with which the engaging convexity of an adjacent core block is engaged.