Patent ID: 6648598
Filing Date: 2003-11-18
Classification: F04D,F05D

Abstract:
An axial flow fan comprising a venturi case having a cylindrical cavity portion, an impeller having a plurality of blades, supported rotatably in the cylindrical cavity portion so that an outer peripheral edge of each of the blades faces to an inner peripheral surface of the cavity portion with a small air gap, and an electric motor for rotating the impeller, wherein the outer peripheral edge of the blade is increased in thickness gradually toward a discharge port side of the venturi case from a suction port side of the venturi case, wherein an outer peripheral edge portion of the blade at a suction port side of the venturi case is bent in the circumferential direction from a negative pressure surface side of the blade, so that the edge is small in thickness, and wherein an outer peripheral edge portion of the blade at a discharge port side of the venturi case has a portion extending circumferentially from a positive pressure surface side of the blade.