Turbine for an exhaust gas turbocharger

Abstract

In a turbine for an exhaust gas turbocharger having a turbine housing including a turbine wheel with blades, each having a leading edge and a trailing edge, an adjusting device is provided controlling the flow to the leading blade edges of the turbine wheel and also a device for controlling the flow from the trailing edges of the turbine wheel blades, both devices are coupled to one another so as to be adjustable by a single actuator.

What is claimed is: 
     
         1 . A turbine ( 32 ) for an exhaust gas turbocharger ( 22 ), having a turbine housing ( 76 ), a turbine wheel ( 74 ) accommodated in the turbine housing ( 76 ) and being rotatable about a rotational axis ( 73 ), the turbine wheel having blades ( 82 ) each with a leading edge ( 90 ) and a trailing edge ( 96 ,  102 ) and being driven by exhaust gas flowing from the turbine housing ( 76 ) to the turbine wheel ( 74 ) and reaching the turbine wheel blade at the leading edge ( 90 ) and leaving the turbine wheel blade via the trailing edge ( 96 ,  102 ), an adjusting device ( 56 ) movable between a first position in which the trailing edge ( 96 ,  102 ) of the impeller blade ( 82 ) of the turbine wheel is enabled fluidly and a second position in which it is at least essentially fluidly blocked, and a further adjusting device ( 54 ) situated in a turbine wheel inlet area ( 110 ) for variably adjusting the flow conditions in the turbine wheel inlet area ( 110 ) upstream of the turbine wheel ( 74 ), the first adjusting device and the second adjusting device ( 54 ,  56 ) being coupled to one another and being operable by means of a single actuator. 
     
     
         2 . The turbine ( 32 ) according to  claim 1 , wherein the adjusting device ( 56 ) is situated, at least in parts, in a turbine wheel outlet area ( 108 ) and is rotatable about the rotational axis ( 73 ) of the turbine wheel ( 74 ). 
     
     
         3 . The turbine ( 32 ) according, to  claim 1 , wherein the adjusting devices ( 54 ,  56 ) are one of electrically, pneumatically, hydraulically and mechanically coupled to one another. 
     
     
         4 . The turbine ( 32 ) according to  claim 1 , wherein the second adjusting device ( 54 ) is rotatable about the rotational axis ( 73 ) of the turbine wheel ( 74 ) for variably adjusting the flow conditions in the turbine wheel inlet area ( 110 ) 
     
     
         5 . The turbine ( 32 ) according to  claim 1 , wherein the turbine wheel blade ( 82 ) of the turbine wheel ( 74 ) has an outer contour ( 86 ) of at least one length range ( 88 ), extending essentially parallel to the rotational axis ( 73 ), and having as the leading edge ( 90 ), and having a length range ( 94 ) extending essentially radially as the trailing edge ( 96 ), whereby between the length range ( 88 ) extending essentially parallel to the rotational axis ( 73 ) and the length range ( 94 ) extending essentially radially, at least one further length range ( 100 ) is provided forming a further trailing edge ( 102 ), and defining an angle α K  with the rotational axis ( 73 ), where α K  is in a range 20°<α K ≦90°. 
     
     
         6 . The turbine ( 32 ) according to  claim 5 , wherein the further trailing edge ( 102 ) may be selectively essentially fluidly enabled, or essentially fluidly blocked, by means of the single adjusting device ( 56 ). 
     
     
         7 . The turbine ( 32 ) according to  claim 1 , wherein the adjusting device ( 56 ) includes a first adjusting element ( 80 ) which is rotationally fixed relative to the turbine housing ( 76 ), and at least one second adjusting element ( 78 ) which is rotatable about the rotational axis ( 73 ) relative to the first adjusting element ( 80 ). 
     
     
         8 . The turbine ( 32 ) according to  claim 1 , wherein the adjusting device ( 56 ) is adjustable about the rotational axis ( 73 ) in an adjustment range of 20 degrees.