Patent ID: 8058760

Claim:
A method of manufacturing a magneto field type motor including a plurality of main magnetic poles made of permanent magnets that are arranged to the inner circumference of a yoke at equal intervals; a plurality of auxiliary poles made of magnetic materials that are arranged to adjoin increasing magnetic flux sides of the main magnetic poles; a plurality of magnet holding springs that are arranged between the auxiliary poles and the decreasing magnetic flux sides of the main magnetic poles, wherein each magnet holding spring is provided in a â€œ]â€-like sectional shape having a back-plate fixed to an inner circumference of the yoke and a pair of side-plates extending in a direction of a center of the yoke from the both sides in a circumferential direction of the back-plate, the main magnetic poles and the auxiliary poles being fixed by being pressed in a circumferential direction by elasticity of the pair of the side-plates, in the stage where the magnet holding spring is deployed as a flat plate before the back-plate and the pair of side-plates are bent into the â€œ]â€-like sectional shape, the auxiliary pole is attached beforehand to one of the side-plates among the pair of side-plates, then the magnet holding spring is bent into the â€œ]â€-like sectional shape, the magnet holding spring and the auxiliary pole attached integrally to constitute a sub-assembly and the magnet holding spring and the auxiliary pole are attached interally by press fitting a concave part provided in either one of the side-plate or the auxiliary pole with a convex part provided in the other one of the side-plates or the auxiliary pole to form the sub-assembly, the method of manufacturing the magneto field type motor comprising: forming a fitting hole that forms the concave part on one of the side-plates of the magnet holding spring by punching; forming the convex part to the auxiliary pole in the position corresponding to the fitting hole by embossing; and assembling the magnet holding spring and the auxiliary pole integrally by press fitting the convex part into the fitting hole.