Fan impeller

Abstract

A fan impeller includes a wheel casing, a plurality of fan blades and a plurality of first wind-guiding structures. The wheel casing is configured to rotate about an axis. The fan blades surround the axis and are arranged in a radial form. Each of the fan blades includes an end edge and two extending edges. The end edge is away from the wheel casing. The extending edges connect between the end edge and the wheel casing. The end edge and the extending edges define a windward surface and a leeward surface opposite to each other. The first wind-guiding structures are respectively disposed on the leeward surface of the corresponding fan blade. Each of the first wind-guiding structures is at least partially adjacent with the end edge and one of the extending edges of the corresponding fan blade.

What is claimed is: 
     
         1 . A fan impeller, comprising:
 a wheel casing configured to rotate about an axis;   a plurality of fan blades surrounding the axis and arranged in a radial form, each of the fan blades includes an end edge and two extending edges, the end edge being away from the wheel casing, the extending edges connecting between the end edge and the wheel casing, the end edge and the extending edges defining a windward surface and a leeward surface opposite to each other; and   a plurality of first wind-guiding structures respectively disposed on the leeward surface of the corresponding fan blade, and each of the first wind-guiding structures being at least partially adjacent with the end edge and one of the extending edges of the corresponding fan blade.   
     
     
         2 . The fan impeller of  claim 1 , wherein the first wind-guiding structures are away from the wheel casing. 
     
     
         3 . The fan impeller of  claim 1 , wherein each of the first wind-guiding structures has a first length, and the first length is perpendicular to the corresponding leeward surface and gradually diminishes in a direction towards the wheel casing. 
     
     
         4 . The fan impeller of  claim 1 , wherein at least two of the fan blades are located between adjacent two of the first wind-guiding structures, the axis penetrates through a center of gravity of the first wind-guiding structures. 
     
     
         5 . The fan impeller of  claim 1 , further comprising:
 a plurality of second wind-guiding structures respectively disposed on the leeward surface of the corresponding fan blade, and each of the second wind-guiding structures being at least partially adjacent with the end edge and another one of the extending edges of the corresponding fan blade.   
     
     
         6 . The fan impeller of  claim 5 , wherein the second wind-guiding structures are away from the wheel casing. 
     
     
         7 . The fan impeller of  claim 5 , wherein each of second first wind-guiding structures has a second length, and the second length is perpendicular to the corresponding leeward surface and gradually diminishes in a direction towards the wheel casing. 
     
     
         8 . The fan impeller of  claim 5 , wherein at least two of the fan blades are located between adjacent two of the second wind-guiding structures, the axis penetrates through a center of gravity of the second wind-guiding structures. 
     
     
         9 . The fan impeller of  claim 5 , wherein the second wind-guiding structures and the first wind-guiding structures are disposed on the same fan blades. 
     
     
         10 . The fan impeller of  claim 5 , wherein the second wind-guiding structures and the first wind-guiding structures are disposed differently on the fan blades.