Patent ID: 7755242

Claim:
A motor comprising: a stator; and a rotor surrounding the stator and rotating by interaction with the stator, wherein the stator comprises: a main core including a base, and a plurality of teeth protruding from the base and having a coil wound thereon; and an auxiliary core structured to prevent spaces between adjacent teeth from functioning as a magnetic resistance while the stator co-operates with the rotor, wherein the auxiliary core comprises: a plate positioned over or beneath the main core, and a shield arranged at and associated with each of the spaces formed between the teeth, wherein each shield comprises: a first extension extending from the plate, and a second extension extending from the first extension such that the second extension is bent from the first extension to shield the associated space, wherein the second extension is arranged outside a circumferential surface of the main core, and has a height larger than a thickness of the main core, wherein a plurality of second extensions are connected together, to form an integrated ring-shaped structure surrounding the circumferential surface of the main core, and wherein the integrated ring-shaped structure has a plurality of slots structured to adjust a size of an exposed area of the spaces.