Turbomachine

Abstract

A turbomachine includes an impeller and, downstream of the impeller, a diffuser limited by an inner and an outer shell. A collection chamber is arranged downstream of the diffuser. The diffuser leads with a mouth cross section into the collection chamber in the radial direction. An exit-side end of the outer shell adjoins, or projects into, the collection chamber. The exit-side end has a first surface portion facing the collection chamber that extends, in cross section, in the radial direction. The first surface portion merges with a second surface portion contoured circular segment-like in the cross section into a third surface portion of the exit-side end of the outer shell facing the diffuser.

1 . A turbomachine comprising:
 an impeller ( 11 );   a diffuser ( 12 ) arranged downstream of the impeller ( 11 ), the diffuser ( 12 ) being limited by an inner shell ( 13 ) and an outer shell ( 14 );   a collection chamber ( 15 ) arranged downstream of the diffuser ( 12 ), wherein the diffuser ( 12 ) in the radial direction leads into the collection chamber ( 15 ) by a mouth cross section ( 16 ); and   an exit-side end ( 17 ) of the outer shell ( 14 ) of the diffuser ( 12 ), the exit-side end ( 17 ) adjoining the collection chamber ( 15 ) or projecting into the collection chamber ( 15 ) at least by a portion of the exit-side end ( 17 ),   wherein the exit-side end ( 17 ) of the outer shell ( 14 ) has a first surface portion ( 18 ) facing the collection chamber ( 15 ), which, in cross section, extends in a radial direction,   the first surface portion ( 18 ) being arranged so as to merge with a second surface portion ( 19 ) contoured circular segment-like in cross section into a third surface portion ( 20 ) of the exit-side end ( 17 ) of the outer shell ( 14 ) facing the diffuser ( 12 ).   
     
     
         2 . The turbomachine according to  claim 1 , wherein the second surface portion ( 19 ) tangentially merges into the first surface portion ( 18 ). 
     
     
         3 . The turbomachine according to  claim 1 , wherein the second surface portion ( 19 ) tangentially merges into the third surface portion ( 20 ) facing the diffuser ( 12 ). 
     
     
         4 . The turbomachine according to  claim 1 , wherein the first surface portion ( 18 ) extends, in the cross section, exclusively in the radial direction. 
     
     
         5 . The turbomachine according to  claim 1 , wherein the first surface portion ( 18 ) has a length L for which the following is true:
   0.1* X≤L≤X,      wherein X is the dimension of the mouth cross section ( 16 ) of the diffuser ( 12 ) in an axial direction.   
     
     
         6 . The turbomachine according to  claim 5 , wherein the second surface portion ( 19 ) has a radius R for which the following is true:
   0.1* X≤R≤X,      wherein X is the dimension of the mouth cross section ( 16 ) of the diffuser ( 12 ) in the axial direction.   
     
     
         7 . The turbomachine according to  claim 1 , wherein the turbomachine comprises an axial turbine. 
     
     
         8 . The turbomachine according to  claim 7 , wherein the axial turbine is a turbine of a turbocharger. 
     
     
         9 . The turbomachine according to  claim 1 , wherein the respective cross section is a meridian section.