Patent ID: 7614250

Claim:
A centrifugal fan comprising: a rotary shaft; an electric motor configured to rotate said rotary shaft; a main plate having a cooling air hole and being coupled to and rotationally driven by said rotary shaft; a plurality of blades provided on the surface of said main plate on a side opposite said electric motor and positioned radially outward from said cooling air hole, said main plate and said blades being configured to suck in air from a rotary shaft direction and blow air out in a direction that intersects said rotary shaft; an air guide coupled to said main plate for rotation therewith proximate said cooling air hole such that, after a portion of the blown out air has been guided to the vicinity of said electric motor and has cooled said electric motor, guides the air flow so that it is blown out toward the side of said main plate in the counter rotational direction when blown out from said cooling air hole to the side of said main plate opposite said electric motor; a cover being coupled to said rotary shaft for rotation with said main plate covering said cooling air hole from the side opposite said electric motor, and being provided to rotate integrally with said main plate; said air guide being formed between said cover on an electric motor side thereof, and said main plate on the side opposite said electric motor, and said air guide having a blade shape inclined rearwards in the rotational direction of said cover.