Axial fan

Abstract

An axial fan includes a rotor portion including a shaft arranged to extend along a central axis extending in a vertical direction, a stator portion arranged radially opposite to the rotor portion, and an impeller hub fixed to the rotor portion, and arranged to be capable of rotating integrally with the rotor portion. The impeller hub includes a hub top plate portion arranged to extend perpendicularly to an axial direction; a hub tubular portion being tubular, and arranged to extend axially downward from an outer edge of the hub top plate portion; a plurality of blades arranged in a circumferential direction on an outer surface of the hub tubular portion; a plurality of wall portions arranged in the circumferential direction radially inside of the hub tubular portion, with a gap between every adjacent ones of the wall portions; and joining portions each of which is arranged to join a corresponding one of the wall portions to the hub tubular portion. The rotor portion includes a rotor tubular portion being tubular and arranged to extend in the axial direction. An outer surface of the rotor tubular portion is arranged to be in contact with an inner surface of at least one of the wall portions. Each of the at least one wall portion arranged to be in contact with the outer surface of the rotor tubular portion is joined to the hub tubular portion through two or more of the joining portions arranged in the circumferential direction.

Dependencies are inferred from the claim text.