Axial flow blower

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.

1 . 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 of said blades, 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 of said blades is not provided with said triangle shape projections but is a smooth continuous surface.   
     
     
         2 . The axial flow blower as set forth in  claim 1 ,
 wherein said triangle shape projections have peaks with slanted side faces.   
     
     
         3 . The axial flow blower as set forth in  claim 1 ,
 wherein said triangle shape projections have peaks with bottom sides which are changed in size as said triangle shape projections closer to an outer circumference of said blower fan.   
     
     
         4 . The axial flow blower as set forth in  claim 1 ,
 wherein said triangle shape projections have peaks with vertexes which are changed in angle as said triangle shape projections closer to an outer circumference of said blower fan.   
     
     
         5 . The axial flow blower as set forth in  claim 1 ,
 wherein said triangle shape projections have peaks with center directions which are changed as said triangle shape projections closer to an outer circumference of said blower fan.   
     
     
         6 . The axial flow blower as set forth in  claim 1 ,
 wherein a blade trailing edge of each said blades is provided in the negative pressure surface and the positive pressure surface with a plurality of triangle shape projections which have vertexes at the blade trailing edge.   
     
     
         7 . The 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 leading edge of each said blade blades, comprised of a negative pressure surface and a positive pressure surface, is provided in the negative pressure surface and the positive pressure surface with a plurality of triangle shape projections which have vertexes along the leading edge, and   angles formed by valleys of said plurality of triangle shape projections at said positive pressure surface are respectively larger than angles formed by said valleys at said negative pressure surface.   
     
     
         8 . The axial flow blower as set forth in  claim 1 ,
 wherein said blower fan has backward curved blades or forward curved blades.   
     
     
         9 . A blower fan which is provided with
 a hub which is attached to a drive device and   a plurality of blades which are provided at said hub and have a negative pressure surface and a positive pressure surface,   wherein in said blower fan, a negative pressure surface of a leading edge of each said blade has   a first slanted side, which is slanted with respect to the flow direction of the air flow, and   a second slanted side, which is slanted with respect to the flow direction of the air flow, in a different direction from said first slanted side and is provided with a plurality of projections which project out into the upstream side of flow of the air flow, and   said positive pressure surface of a leading edge of each said blade is not provided with said triangle shape projections but is a smooth continuous surface.