Patent ID: 8651807

Claim:
A fan comprising: an impeller including a plurality of blades; a motor including a rotary shaft for rotating the impeller; and a housing having a suction port, a discharge port, and an air channel that houses at least the impeller and allows an air to be sucked from the suction port and discharged from the discharge port when the impeller rotates, wherein: a surface of the housing, in which the suction port is formed, is substantially rectangular in profile; four tapered portions are formed on an end portion of an inner wall surface of the air channel at four locations corresponding to four corners of the profile of the surface of the housing where the suction port is formed, the four tapered portions are each inclined outwardly in a radial direction of the rotary shaft from the discharge port side toward the suction port side and extending in a rotational direction of the impeller; and the tapered portions each include a main portion which is shaped such that an angle formed between the main portion and an axis of the rotary shaft gradually becomes smaller from one end of the main portion located rearward as viewed in the rotational direction of the impeller toward the other end of the main portion located forward as viewed in the rotational direction of the impeller.