Variable turbine geometry turbocharger

Abstract

A turbocharger is provided having a turbine wheel ( 4, 4′ ) with a plurality of extended tips ( 400, 400′ ); and a variable turbine geometry assembly in fluid communication with the turbine wheel and having a nozzle ring ( 6 ) with a plurality of vanes ( 7 ) movably attached thereto. One or more of the extended tips are non-parallel with an edge of one or more of the plurality of vanes. The incidence angle can vary and can be from 1 to 60 degrees. The extended tips can extend into an inlet of the vane space housing the vanes.

1 . A turbocharger ( 1 ) comprising:
 a turbine wheel ( 4 ,  4 ′) having a plurality of extended tips ( 400 ,  400 ′); and   a variable turbine geometry assembly in fluid communication with the turbine wheel and having a nozzle ring ( 6 ) with a plurality of vanes ( 7 ) movably attached thereto, wherein one or more of the extended tips are non-parallel with an edge of one or more of the plurality of vanes.   
   
   
       2 . The turbocharger of  claim 1 , wherein all of the extended tips are non-parallel with all of the edges of the plurality of vanes. 
   
   
       3 . The turbocharger ( 1 ) of  claim 1 , wherein the extended tips are at an angle with the edges of the plurality of vanes of between 1 and 60 degrees. 
   
   
       4 . The turbocharger ( 1 ) of  claim 1 , wherein the extended tips are at an angle with the edges of the plurality of vanes of between 5 and 45 degrees. 
   
   
       5 . The turbocharger ( 1 ) of  claim 1 , wherein the extended tips are at an angle with the edges of the plurality of vanes of between 10 and 30 degrees. 
   
   
       6 . The turbocharger ( 1 ) of  claim 1 , wherein the plurality of vanes are positioned in a vane space ( 13 ) that is in fluid communication with the turbine wheel, wherein the vane space has an inlet ( 500 ) and wherein the extended tips extend into the inlet. 
   
   
       7 . A method of operating a turbocharger ( 1 ), the method comprising:
 providing an exhaust gas flow to a turbine wheel ( 4 ) of a variable turbine geometry turbocharger, wherein the exhaust gas flow is a mixed flow having both a radial component and an axial component, and wherein the mixed flow is formed by at least one of leakage gas, secondary flow and a non-parallel incidence angle of the turbine wheel.   
   
   
       8 . The method of  claim 7 , comprising providing extended tips for the turbine wheel, wherein the extended tips are at an angle with edges of plurality of vanes of between 1 and 60 degrees. 
   
   
       9 . The method of  claim 7 , comprising providing extended tips for the turbine wheel, wherein the extended tips are at an angle with edges of plurality of vanes of between 5 and 45 degrees. 
   
   
       10 . The method of  claim 7 , comprising providing extended tips for the turbine wheel, wherein the extended tips are at an angle with edges of plurality of vanes of between 10 and 30 degrees. 
   
   
       11 . The method of  claim 8 , wherein the plurality of vanes are positioned in a vanes space ( 13 ) that is in fluid communication with the turbine wheel, wherein the vane space has an inlet ( 500 ) and wherein the extended tips extend into the inlet.