Abstract: An air blower is provided with a drive motor and an air blowing fan which has a hub mounted to the drive motor and blades which are provided to the hub. The air blower is characterized in that serrations comprising triangle-shaped protrusions are provided to the front edge of each of the blades so as to be arranged along the front edge and in that the pitch, the height, or the direction of the serrations is changed according to the flow of air at a radial position on the air blowing fan.

Abstract: TECHNICAL PROBLEM To provides a blower which aims at both a noise reduction effect and the inherent blowing performance SOLUTION TO PROGRAM An axial flow blower which is provided with an electric motor, and a blower fan which has a hub which is attached to said electric motor and a plurality of blades which are provided at said hub in a radial manner, wherein in said axial flow blower, a negative pressure surface of a leading edge of each said blade, comprised of a negative pressure surface and a positive pressure surface, is provided with a plurality of triangle shape projections which have vertexes along the leading edge, and the positive pressure surface of the leading edge of each said blade is not provided with said triangle shape projections but is a smooth continuous surface.