Axial flow fan structure

Abstract

The present invention provides an axial flow fan structure having an optimal airflow rate and pressure head. The axial flow fan structure includes a rotor provided with a plurality of fan blades which are overlapped with each other. In such a manner, variations of the chord angle, the air inlet angle, and the air outlet angle of the fan blade together with adjustment of the span of the fan blades co-operate with rotation of the fan blade to produce an optimal airflow rate and pressure head. In addition, the fan blades of the rotor may co-operate with a set of stator guide vanes, thereby further increase the pressure head of the airflow, while the airflow having a high flow rate and high pressurization is guided to a predetermined direction more efficiently.

What is claimed is:  
     
         1 . An axial flow fan structure comprising: a rotor ( 20 ) provided with a plurality of fan blades ( 21 ), each of said fan blades ( 21 ) including a chord angle (“A”), an air inlet angle (“B”), and an air outlet angle (“C”), variations of said chord angle (“A”), said air inlet angle (“B”), and said air outlet angle (“C”) of said fan blade ( 21 ) co-operate with rotation of said fan blade ( 21 ) to produce a pressurized airflow rate; 
 wherein, said fan blades ( 21 ) are arranged in a head-tail overlap arrangement manner with each other, so that more fan blades ( 21 ) may be arranged in said axial flow fan structure in a head-tail overlap arrangement manner of said fan blades ( 21 ), an overlap distance (“D”) of said fan blades ( 21 ) is greater than zero and smaller than one third of a blade average distance (“E”), said chord angle (“A”) of each of said fan blades ( 21 ) is ranged between twenty degrees and sixty degrees, and said overlapped fan blades ( 21 ) have an action surface while the total action area is increased to co-operate with said chord angle (“A”) of each of said fan blades ( 21 ), for generating a higher airflow rate and total pressure head with the greatest efficiency.  
 
     
     
         2 . An axial flow fan structure comprising: a rotor ( 20 ) provided with a plurality of fan blades ( 21 ), each of said fan blades ( 21 ) including a chord angle (“A”), an air inlet angle (“B”), and an air outlet angle (“C”), variations of said chord angle (“A”), said air inlet angle (“B”), and said air outlet angle (“C”) of said fan blade ( 21 ) co-operate with rotation of said fan blade ( 21 ) to produce a pressurized airflow rate; 
 wherein, said fan blades ( 21 ) are arranged in a head-tail overlap arrangement manner with each other, a set of stator guide vanes ( 31 ), are sealingly mounted on a predetermined airflow direction side of said fan blades ( 21 ), each of said stator guide vanes ( 31 ) includes a chord angle (“a”), an air inlet angle (“b”), and an air outlet angle (“c”), and variations of said chord angle (“a”), said air inlet angle (“b”), and said air outlet angle (“c”) of said stator guide vane ( 31 ) further increase a pressurization of said pressurized airflow rate, while said airflow having a high flow rate and pressure head can be guided more efficiently to a predetermined direction.  
 
     
     
         3 . The axial flow fan structure in accordance with  claim 2 , wherein said stator guide vane ( 31 ) has a configuration that can be adjusted according to a requirement of a generated airflow rate of said rotor ( 20 ).