Patent ID: 7495362
Filing Date: 2009-02-24
Classification: F04D,H02K

Abstract:
1. An electrical fan comprising: a fan housing having a central tube extending therein, the housing defining an air inlet and an air outlet at two different sides thereof; a bearing received in the central tube; a stator mounted around the central tube, the stator comprising a stator core having a disc-shaped top wall and a sidewall extending downwardly from an outer periphery of the top wall, a tube extending downwardly from a central portion of the top wall, and windings wound around the tube, the sidewall expanding radially along a direction from the air inlet to the air outlet; and a rotor being rotatably supported by the bearing in the central tube the rotor comprising a hub having a shape substantially corresponding to the stator and expanding radially along the direction from the air inlet to the air outlet, and a plurality of fan blades extending radially from the hub towards the fan housing, a length of each of the fan blades in a radial direction of the hub gradually increasing along a direction from the air outlet to the air inlet for increasing a size of the each of the fan blades.