Axial flow fan

Abstract

The invention relates to an axial flow fan (1) comprising a stationary hub (2); comprising an annular stationary frame (3), which surrounds the hub (2) on the outer peripheral side and which is connected to the stationary hub (2) via at least one strut (4, 5, 6); and comprising a fan wheel (8), which is in drive connection with a fan wheel drive (9), which has a rotating fan wheel hub (10), and which has a plurality of fan wheel blades (11), which each comprise a back edge (12), characterized in that the contour of the strut (4, 5, 6) is designed as sine wave shaped, and wherein the back edge (12) is preferably designed as toothed at least in a partial area (13).

1 . An axial flow fan ( 1 )
 comprising a stationary hub ( 2 );   comprising an annular stationary frame ( 3 ), which surrounds the hub ( 2 ) on the outer peripheral side and which is connected to the stationary hub ( 2 ) via at least one strut ( 4 ,  5 ,  6 ); and   comprising a fan wheel ( 8 ),   which is in drive connection with a fan wheel drive ( 9 ),   which has a rotating fan wheel hub ( 10 ), and   which has a plurality of fan wheel blades ( 11 ), which each comprise a back edge ( 12 ), wherein the back edge ( 12 ) faces the at least one strut ( 4 ,  5 ,  6 ), characterized in that   the contour of the strut ( 4 ,  5 ,  6 ) is designed as sine wave shaped, and wherein the back edge ( 12 ) is preferably designed as toothed at least in a partial area ( 13 ).   
     
     
         2 . The axial flow fan according to  claim 1 , characterized in that a plurality of struts ( 4 ,  5 ,  6 ) is provided, of which each has a sine wave shaped contour. 
     
     
         3 . The axial flow fan according to  claim 2 , characterized in that the plurality of struts ( 4 ,  5 ,  6 ) is distributed in strut groups ( 14 - 19 ) arranged spaced apart from one another. 
     
     
         4 . The axial flow fan according to  claim 1 , characterized in that the strut ( 4 ,  5 ,  6 ) has a front side ( 7 ) which is designed as sine wave shaped. 
     
     
         5 . The axial flow fan according to  claim 1 , characterized in that the strut ( 4 ,  5 ,  6 ) is designed as asymmetrical. 
     
     
         6 . The axial flow fan according to  claim 1 , characterized in that the strut ( 4 ,  5 ,  6 ) has an inflow surface ( 24 ) which inclines from inside to outside when viewed in the flow direction. 
     
     
         7 . The axial flow fan according to  claim 1 , characterized in that the geometry of the strut ( 4 ,  5 ,  6 ) is aerodynamically optimized to achieve a low air resistance. 
     
     
         8 . The axial flow fan according to  claim 1 , characterized in that the fan wheel blades ( 11 ) are arranged spaced equally apart from one another. 
     
     
         9 . The axial flow fan according to  claim 1 , characterized in that the fan wheel blades ( 11 ) are arranged spaced unequally apart from one another. 
     
     
         10 . The axial flow fan according to  claim 1 , characterized in that the toothed partial area ( 13 ) is arranged adjacent to the frame ( 3 ). 
     
     
         11 . The axial flow fan according to  claim 4 , characterized in that the front side ( 7 ) of the strut ( 4 ,  5 ,  6 ) is not arranged parallel to the back edge ( 12 ) of the fan wheel blades ( 11 ).