Air-cooled generator

Abstract

The present invention relates to an air-cooled generator, through which cooling air flows for the removal of heat loss, wherein the cooling air sweeps over boundary surfaces ( 23 ) acting as cooling surfaces and, in so doing, absorbs heat from these boundary surfaces ( 23 ). The heat transfer is maximized with minimal cooling air consumption since the boundary surfaces ( 23 ) are provided with distributed local elevations ( 24 ) enlarging the cooling surface and the heat transfer coefficient. In particular, local elevations in the form of pyramid-shaped or truncated-pyramid-shaped bodies ( 24, 26, 29 ) are preferred.

1 . An air-cooled generator ( 10 ), through which cooling air flows for the removal of heat loss, wherein the cooling air sweeps over boundary surfaces ( 23 ) acting as cooling surfaces and, in so doing, absorbs heat from these boundary surfaces ( 23 ), characterized in that the boundary surfaces ( 23 ) are provided with distributed local elevations ( 24 - 29 ) enlarging the cooling surface. 
     
     
         2 . The generator as claimed in  claim 1 , wherein the local elevations ( 24 - 29 ) are distributed uniformly over the cooling surface ( 23 ) and form a pattern. 
     
     
         3 . The generator as claimed in  claim 1 , wherein the local elevations have the form of simple geometric bodies. 
     
     
         4 . The generator as claimed in  claim 3 , wherein the local elevations have the form of pyramids ( 24 ,  26 ) or truncated pyramids ( 29 ). 
     
     
         5 . The generator as claimed in  claim 4 , wherein the pyramids ( 24 ,  26 ) or truncated pyramids ( 29 ) have a quadrangular base area. 
     
     
         6 . The generator as claimed in  claim 5 , wherein the pyramids ( 24 ,  26 ) or truncated pyramids ( 29 ) have a rectangular base area. 
     
     
         7 . The generator as claimed in  claim 4 , wherein the pyramids ( 24 ,  26 ) or truncated pyramids ( 29 ) have a triangular base area and in particular are formed as tetrahedrons. 
     
     
         8 . The generator as claimed in  claim 4 , wherein a side face of the pyramids ( 24 ,  26 ) or of the truncated pyramid ( 29 ) subject to an incident flow is oriented transverse to the primary direction of flow of the cooling medium. 
     
     
         9 . The generator as claimed in  claim 6 , wherein a longer side edge of the pyramids ( 24 ,  26 ) or of the truncated pyramid ( 29 ) is oriented transverse to the primary direction of flow of the cooling medium. 
     
     
         10 . The generator as claimed in  claim 3 , wherein the local elevations have the form of cones ( 25 ) or truncated cones. 
     
     
         11 . The generator as claimed in  claim 3 , wherein the local elevations have the form of cylinders ( 27 ) or rectangular parallelepipeds ( 28 ). 
     
     
         12 . The generator as claimed in  claim 1 , wherein the generator ( 10 ) comprises a rotor with a plurality of poles ( 11 ), which are separated from one another by pole gaps ( 14 ) and are each provided with a pole winding ( 12 ), and in that the cooling surfaces provided with the local elevations ( 24 - 29 ) are arranged in the pole gap region ( 15 ), for example on one or more pole winding surfaces or pole body surfaces. 
     
     
         13 . The generator as claimed in  claim 1 , wherein the generator ( 10 ) comprises a rotor with a polarity of poles ( 11 ), which are separated from one another by pole gaps ( 14 ) and are each provided with a pole winding ( 12 ), and in that the cooling surfaces provided with the local elevations ( 24 - 29 ) are arranged in the region of the rear ventilation ( 16 ) of the pole windings ( 12 ). 
     
     
         14 . The generator as claimed in  claim 2 , wherein the local elevations have the form of simple geometric bodies. 
     
     
         15 . The generator as claimed in  claim 6 , wherein a side face of the pyramids ( 24 ,  26 ) or of the truncated pyramid ( 29 ) subject to an incident flow is oriented transverse to the primary direction of flow of the cooling medium and wherein a longer side edge of the pyramids ( 24 ,  26 ) or of the truncated pyramid ( 29 ) is oriented transverse to the primary direction of flow of the cooling medium.