Turbine for an exhaust gas turbocharger

Abstract

In a turbine for exhaust gas turbocharger of a combustion engine with a turbine casing forming an installation space in which a turbine wheel is arranged so as to be rotatable about an axis of rotation and into which exhaust gas of the combustion engine may be supplied via at least one flow duct in which a guide vane structure is arranged, the guide vane structure includes vanes, which are pivotably supported relative to the turbine casing and form an axial inlet nozzle structure adjacent a wall portion of the turbine which extends along the guide vane structure, the wall portion comprising at least a first guide wall area which overlaps the guide vane structure, and which is set back relative to a second guide wall area in which the vanes are pivotably supported and which adjoins the first wall area.

What is claimed is: 
     
         1 . A turbine for an exhaust gas turbocharger of a combustion engine, comprising a turbine casing ( 14 ) including an installation space ( 18 ), a turbine wheel ( 20 ) arranged in the installation space ( 18 ) so as to be rotatable about an axis of rotation ( 22 ) at least one inlet flow duct ( 38 ) via which exhaust gas of the combustion engine may be supplied to the turbine wheel ( 20 ), a guide vane structure ( 72 ) arranged in the inlet flow duct ( 38 ) and including vanes which are pivotably supported relative to the turbine casing ( 14 ), the vane structure ( 72 ) being delimited in the axial direction of the installation space ( 18 ) at least partially by at least one wall portion ( 70 ) of the turbine ( 12 ) which is at least partially overlapping the guide vane structure ( 72 ), the wall portion ( 70 ) comprising a first wall area ( 80 ) which is arranged adjacent the guide vane ( 72 ), and which is set back relative to a second wall area ( 82 ) of the wall portion ( 70 ) adjoining the first wall area ( 80 ). 
     
     
         2 . The turbine according to  claim 1 , wherein the wall portion ( 70 ) with the first wall area ( 80 ) and the second wall area ( 82 ) is arranged at the side of the guide vane structure ( 72 ) facing the turbine wheel outlet area ( 52 ) of the turbine ( 12 ). 
     
     
         3 . The turbine according to  claim 1 , wherein the first wall area ( 80 ) and the second wall area ( 82 ) are joined via a third wall area ( 84 ) of the wall portion ( 70 ), which is arranged between the first wall area ( 80 ) and the second wall area ( 82 ), and forms with the first wall area ( 80 ) and the second wall area ( 82 ) an angle of essentially 90°. 
     
     
         4 . The turbine according to  claim 1 , wherein the first wall area ( 80 ) and the second wall area ( 82 ) are joined via a third wall area ( 84 ) of the wall portion ( 70 ), which extends between the first wall area ( 80 ) and the second wall area ( 82 ), and is essentially arc-shaped. 
     
     
         5 . The turbine according to  claim 1 , wherein the wall portion ( 70 ) is in the form of a cover plate ( 70 ), which is an insert component formed separately from the turbine casing ( 14 ) and which is at least partially accommodated in the installation space ( 18 ), and which extends at least over part of the blade edges ( 48 ) of the turbine wheel ( 20 ). 
     
     
         6 . The turbine according to  claim 5 , wherein the cover plate ( 70 ) has a cover contour ( 74 ) which is essentially complementary to the contour of the blade edges ( 48 ). 
     
     
         7 . The turbine according to  claim 1 , wherein the guide vane structure ( 72 ) abuts a retaining component which is formed separately from the turbine casing ( 14 ), in the form of a nozzle ring ( 66 ) which is supported in the turbine casing ( 14 ).