Patent ID: 8794935

Claim:
A polyphase motor comprising: a shaft; a rotor magnet arranged concentrically with the shaft to rotate therewith; a stator including a plurality of magnetic pole teeth arranged to radially oppose the rotor magnet, and a plurality of coils each defined by a wound conductive wire; and a bearing mechanism arranged to support the shaft with respect to the stator in a rotatable manner; a case including a tubular portion housing the stator therein, and a bottom portion arranged below the rotor magnet and including a plurality of through holes; and a substrate arranged to connect end portions of the coils, the substrate includes a plurality of extending portions extending radially outward from a center of the substrate, a number of the plurality of extending portions corresponding to a number of phases of the polyphase motor; wherein the substrate is arranged at the bottom portion; a portion of the bottom portion includes an opposing surface arranged to axially oppose the substrate with a gap therebetween and also includes substantially arcuate plate-shaped projections provided together with the bottom portion of the case as a single monolithic member, at least three of the substantially arcuate plate-shaped projections being arranged at uniformly spaced apart circumferential positions; the opposing surface includes the plurality of through holes and the substantially arcuate plate-shaped projections are arranged radially outward from the plurality of through holes; the bottom portion includes at least one attachment hole arranged to connect the case to an external element, the at least one attachment hole being separate from the plurality of through holes; and the substrate is directly attached to the substantially arcuate plate-shaped projections.