Micro-fan

Abstract

Disclosed herewith is a micro-fan. The micro-fan includes a hub attached to a rotating shaft and a plurality of blades extended from the side surface of the hub. In the micro-fan, if a leading edge is defined as the foremost edge of each of the blades consisting of a straight line portion and one or more arc portions, a trailing edge is defined as the rearmost edge of each of the blades, a chord line is defined as a line connecting two opposite points respectively situated in the leading and trailing edges and a blade angle is defined as an angle formed by the chord line and the horizontal line passing through the same point of the leading edge as that through which the chord line passes and lying in the same vertical plane as that in which the leading edge lies, the straight line portions of the leading and trailing edges are perpendicular to the hub and form a predetermined inside angle.

What is claimed is:  
     
         1 . A micro-fan, comprising: 
 a hub attached to a rotating shaft; and    a plurality of blades extended from the side surface of said hub;    wherein, if a leading edge is defined as the foremost edge of each of said blades, a trailing edge is defined as the rearmost edge of each of said blades consisting of a straight line portion and one or more arc portions, a chord line is defined as a line connecting two opposite points respectively situated in the leading and trailing edges and a blade angle is defined as an angle formed by said chord line and the horizontal line passing through the same point of the leading edge as that through which the chord line passes and lying in the same vertical plane as that in which the leading edge lies, the straight line portions of said leading and trailing edges are perpendicular to said hub and form a predetermined inside angle.    
     
     
         2 . The micro-fan according to  claim 1 , wherein said leading and trailing edges have straight line portions that form an inside angle ranging from 30 to 60°.  
     
     
         3 . The micro-fan according to  claim 1 , wherein said leading and trailing edges have straight line portions that extend over about 50 to 70% of a blade width that ranges from the innermost edge to the outermost edge of said blade.  
     
     
         4 . The micro-fan according to  claim 1 , wherein said blade has a length ranging from said leading edge to said trailing edge, said length being increased in a radially outward direction.  
     
     
         5 . The micro-fan according to  claim 1 , wherein said blade angle is gradually reduced in a radially outward direction.