Axial flow fan blade structure and axial flow fan thereof

Abstract

An axial flow fan blade structure and an axial flow fan thereof. The axial flow fan blade structure includes a fan impeller and an annular body. The fan impeller has a hub and multiple blades. Each blade has a first flow guide face and a second flow guide face opposite to the first flow guide face. The annular body is disposed on the blades. The annular body outward extends from the first and second flow guide faces and is annularly connected with the blades along the blades. The annular body not only is able to increase the strength of the blades of the axial flow fan, but also is able to reduce vibration and noise made by the axial flow fan.

What is claimed is: 
     
         1 . An axial flow fan blade structure comprising:
 a fan impeller having a hub and multiple blades annularly arranged along a circumference of the hub, each blade having a first flow guide face and a second flow guide face opposite to the first flow guide face; and   an annular body disposed on the blades, the annular body outward extending from the first and second flow guide faces and being annularly connected with the blades along the blades.   
     
     
         2 . The axial flow fan blade structure as claimed in  claim 1 , wherein the annular body has multiple connection sections and multiple protrusion sections, the connection sections being connected between the adjacent blades, the protrusion sections outward extending and protruding from the first and second flow guide faces, two sides of each protrusion section extending to respectively connect with two adjacent connection sections to form the annular body. 
     
     
         3 . The axial flow fan blade structure as claimed in  claim 1 , wherein each blade has a front section, a middle section and a rear section, the rear section being fixedly connected to the circumference of the hub, the middle 
     
     
         4 . The axial flow fan blade structure as claimed in  claim 3 , wherein the annular body is disposed between the front sections and the rear sections of the blades. 
     
     
         5 . The axial flow fan blade structure as claimed in  claim 3 , wherein the annular body is selectively disposed on the front sections of the blades or the rear sections of the blades. 
     
     
         6 . The axial flow fan blade structure as claimed in  claim 1 , wherein the annular body is integrally formed on the blades by injection molding. 
     
     
         7 . An axial flow fan comprising:
 a frame body having a receiving space and a shaft seat disposed at a center of the receiving space;   a fan impeller rotatably assembled with the shaft seat, the fan impeller having a hub and multiple blades annularly arranged along a circumference of the hub, each blade having a first flow guide face and a second flow guide face opposite to the first flow guide face; and   an annular body disposed on the blades, the annular body outward extending from the first and second flow guide faces and being annularly connected with the blades along the blades.   
     
     
         8 . The axial flow fan as claimed in  claim 7 , wherein the annular body has multiple connection sections and multiple protrusion sections, the connection sections being connected between the adjacent blades, the protrusion sections outward extending and protruding from the first and second flow guide faces, two sides of each protrusion section extending to respectively connect with two adjacent connection sections to form the annular body. 
     
     
         9 . The axial flow fan as claimed in  claim 7 , wherein each blade has a front section, a middle section and a rear section, the rear section being fixedly connected to the circumference of the hub, the middle section outward extending from the rear section to connect with the front section. 
     
     
         10 . The axial flow fan as claimed in  claim 9 , wherein the annular body is disposed between the front sections and the rear sections of the blades. 
     
     
         11 . The axial flow fan as claimed in  claim 9 , wherein the annular body is selectively disposed on the front sections of the blades or the rear sections of the blades. 
     
     
         12 . The axial flow fan as claimed in  claim 7 , wherein the annular body is integrally formed on the blades by injection molding.