Combination axial-flow fan

Abstract

A high-performance low-noise combination axial-flow fan includes a fan hub that has a center connection portion for the connection of a fan motor shaft and a mounting groove extending around the periphery, and fan blades each having a wedge block disposed at the inner end for fastening to the mounting groove to secure the respective fan blade to the fan hub in such a manner that no gap is seen between each two adjacent fan blades when viewed from the front side.

1 . A combination axial-flow fan, comprising:
 a fan hub, said fan hub comprising a center connection portion for the connection of a fan motor shaft and a mounting groove extending around the periphery thereof; and   a plurality of fan blades, each said fan blade comprising a wedge block disposed at an inner end thereof for fastening to said mounting groove to secure the respective fan blade to said fan hub.   
   
   
       2 . The combination axial-flow fan as claimed in  claim 1 , wherein said mounting groove is a continuous groove extending all around the periphery of said fan hub near a front side of said fan hub, having an open side extending in a direction toward a rear side of said fan hub; and
 the wedge block of each said fan blade is smoothly arched to fit the periphery of said fan hub, having a top protrusion for engagement into said mounting groove of said fan hub and a bottom locating groove for mounting a retaining ring to secure said fan blades to the periphery of said fan hub.   
   
   
       3 . The combination axial-flow fan as claimed in  claim 2 , wherein said fan hub comprises a set of positioning teeth arranged around the periphery thereof; and
 the wedge block of each said fan blade comprises a set of positioning teeth for engagement with the positioning teeth of said fan hub.   
   
   
       4 . The combination axial-flow fan as claimed in  claim 2 , wherein the wedge block of each said fan blade comprises a retaining flange disposed at one lateral side thereof and a retaining groove disposed at an opposite lateral side thereof, the retaining flange of the wedge block of one said fan blade being engaged with the retaining groove of the wedge block of an adjacent said fan blade. 
   
   
       5 . The combination axial-flow fan as claimed in  claim 4 , wherein said retaining groove of each said wedge block has an expanded portion, and said retaining flange of each said wedge block has an expanded distal end fitting the expanded portion of said retaining groove.