Patent attributes
An axial fan includes a rotor portion, 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; 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; a plurality of wall portions arranged in the circumferential direction radially inside of the hub tubular portion; and a joining portion arranged to join a corresponding one of the wall portions to the hub tubular portion. A radially 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.
