Patent ID: 7824154

Claim:
An axial fan comprising: a cup centered on a rotation axis and having at least a hollow, generally cylindrical portion; a plurality of blades extending from an outer side surface of the cup in a radial direction perpendicular to or substantially perpendicular to the rotation axis, and turning about the rotation axis together with the cup to generate an axial airflow; a housing defining a passage arranged to channel the airflow therein with an air inlet at one of axial ends of the passage and an air outlet at the other axial end, the air being drawn into the passage from the air inlet and being discharged from the air outlet, the housing including an air-inlet side portion having an inner diameter with a cross-sectional area of the passage on a plane perpendicular to the axial direction that increases toward the air inlet; a motor, accommodated in the cup, arranged to rotate the cup; a base portion arranged to support the motor; and a plurality of ribs extending from the base portion to the housing to connect the base portion to the housing, wherein each blade is connected to the cup at a root portion, an air-inlet side end of the root portion is located below an uppermost portion of the cup, and an air-inlet side end of a radially outer edge of each blade is located above the uppermost portion of the cup and axially between an air-inlet side end of the housing and a portion of the housing at which a cross-sectional area of the passage on a plane perpendicular to the rotation axis is the smallest.