Axial Ventilator

Abstract

The invention relates to an axial ventilator for the cooling device of an internal combustion engine, in particular for a motor vehicle, wherein said axial ventilator comprises a rotatably driven hub ( 2 ) provided with air blades ( 11 - 19 ) which are fixed thereto and radially inwardly limited by an internal diameter (Di) and radially outwardly limited by an external diameter (Da). In order to obtain a small-sized axial ventilator, the ratio between the internal (Di) and external (Da) diameters is greater than 40%.

1 . An axial fan for a radiator of an internal combustion engine comprising a rotatably driven hub, with fan blades that are fixed to said hub and limited radially inward by an inside diameter (Di) and radially outward by an outside diameter (Da), wherein the ratio of the inside diameter (Di) to the outside diameter (Da) is greater than 40 percent. 
   
   
       2 . The axial fan according to  claim 1 , wherein the ratio of the fan blade areas projected on a fan passage area enclosed between the inside diameter (Di) and the outside diameter (Da) by the fan blades to the fan passage area is greater than 60 percent. 
   
   
       3 . The axial fan according to  claim 1 , wherein the fan blades are crescent-shaped in a direction extending opposite to the air flow-through direction. 
   
   
       4 . The axial fan according to  claim 1 , wherein each of the fan blades has a front edge that has a parabolic shape. 
   
   
       5 . The axial fan of  claim 4 , wherein the parabolic shape has an origin or vertex and a fan passage area is enclosed between (Di) and (Da), and an intersecting point between the front edge of the corresponding fan blade coincides with the original or vertex of the parabolic shape. 
   
   
       6 . The axial fan of  claim 1 , wherein a fan passage area is enclosed between (Di) and (Da) and the fan passage area has a radius, and wherein each of the fan blades has a front edge, and an angle of attack on the front edge, wherein the angle of attack is greater than 20 degrees over the radius of the fan passage area. 
   
   
       7 . The axial fan of  claim 1 , wherein a fan passage area is enclosed between (Di) and (Da) and the fan passe area has a radius, wherein the fan blades have a profile length that is nearly constant over the radius of the fan passage area. 
   
   
       8 . The axial fan according to  claim 7 , wherein deviations of the profile length from an average profile length are smaller than ±6 percent. 
   
   
       9 . The axial fan according to  claim 1 , wherein hub ramps are provided on the hub of the fan arranged such that the hub ramps respectively ascend opposite to the rotating direction and are outwardly limited by an outside surface, wherein the hub has a radius that is essentially constant in the axial direction. 
   
   
       10 . A radiator for an internal combustion engine through which a medium flows, for cooling the internal combustion engine, wherein said radiator comprises an air passage area, through which an air flow flows along a first air flow path that can be shut by a louver in a dynamic pressure mode and through which an air flow flows along a second air flow path in a fan mode, and wherein the second air flow path extends through a fan according to  claim 1  that is arranged between the radiator and the internal combustion engine. 
   
   
       11 . The axial fan according to  claim 2 , wherein each of the fan blades has a front edge has a parabolic shape. 
   
   
       12 . The axial fan according to  claim 3 , wherein each of the fan blades has a front edge has a parabolic shape. 
   
   
       13 . The axial fan of  claim 2 , wherein the fan passage area has a radius and wherein a fan passage area is enclosed between (Di) and (Da) and the fan passage area has a radius, and wherein each of the fan blades has a front edge, and an angle of attack on the front edge, wherein the angle of attack is greater than 20 degrees over the radius of the fan passage area. 
   
   
       14 . The axial fan of  claim 3 , wherein a fan passage area is enclosed between (Di) and (Da) and the fan passage area has a radius, and wherein each of the fan blades has a front edge, and an angle of attack on the front edge, wherein the angle of attack is greater than 20 degrees over the radius of the fan passage area. 
   
   
       15 . The axial fan of  claim 4 , wherein a fan passage area is enclosed between (Di) and (Da) and the fan passage area has a radius, and wherein each of the fan blades has a front edge, and an angle of attack on the front edge, wherein the angle of attack is greater than 20 degrees over the radius of the fan passage area.