Patent ID: 8247935

Claim:
A brushless motor stator comprising: a stator core including a plurality of stator magnetic poles disposed at predetermined intervals around a center line that coincides with a center of rotation of a rotor including a plurality of rotor magnetic poles formed of permanent magnets; a plurality of winding portions formed by winding winding conductors around the stator magnetic poles; a slot insulator made of an insulating resin and attached to the stator core in order to electrically insulate the stator core and the winding portions; and a circuit substrate including at least one hall element that detects a positional relationship between the rotor magnetic poles and the stator magnetic poles, and positioned at one end portion of the slot insulator through a fitting position determining structure, the one end portion of the slot insulator being located in one direction where the center line extends, wherein the fitting position determining structure comprises: a plurality of fitting concave portions provided in the slot insulator and disposed along a virtual circle centering on the center line; and at least one fitting convex portion provided on the circuit substrate, the at least one fitting convex portion being fitted in at least one of the fitting concave portions included in the plurality of fitting concave portions when the circuit substrate is shifted by a certain angle around the center line; the fitting position determining structure is configured to change a mounting position of the circuit substrate relative to the stator magnetic poles to allow selection of the positional relationship between the at least one hall element and the stator magnetic poles from among a plurality of predetermined positional relationships of the at least one hall element relative to the stator magnetic poles; the stator core includes the stator magnetic poles on an outer circumferential portion of an annular yoke; a cylindrical portion extending in the one direction is integrally provided at a central portion of the one end portion of the slot insulator; an annular portion having a smaller outer diameter than the cylindrical portion is integrally and concentrically provided with the cylindrical portion at an end portion of the cylindrical portion in the one direction; the fitting concave portions are formed in the annular portion; and the circuit substrate has at a central portion thereof a through-hole in which an outer circumferential portion of the annular portion is fitted, and the at least one fitting convex portion is integrally formed at an inner circumferential wall portion surrounding the through-hole.