Diffuser for a turbocharger having an adjustable turbine geometry and turbocharger for an internal combustion engine

Abstract

In a diffuser for a turbocharger having an adjustable turbine geometry wherein the diffuser comprises an axial slide and an adjusting device for moving the axial slide and wherein the adjusting device comprises an adjusting fork having an opening with a guide axis for the accommodation of a guide element and the adjusting device further comprises an adjusting lever with a lever end, the lever end is accommodated in a recess of the adjusting fork which is disposed at a side of the adjusting fork facing the axial slide in order to minimize tilting forces and provide for smooth sliding movement of the fork.

1 . A diffuser for a turbocharger having an adjustable turbine geometry, the diffuser ( 10 ) comprising an axial slide ( 12 ) and an adjusting device ( 16 ) for positioning the axial slide ( 12 ), the adjusting device ( 16 ) comprising an adjusting fork ( 17 ) having an opening ( 23 ) with a guide axis ( 24 ) accommodating a guide element ( 19 ) and further comprising an adjusting lever ( 20 ) with a lever end ( 28 ), the adjusting fork ( 17 ) having at least one contact surface ( 35 ,  36 ), in body contact with the axial slide ( 12 ),
 the adjusting fork ( 17 ) having an engagement recess ( 25 ) for the accommodation of the lever end ( 28 ), the engagement recess ( 25 ) with its contact surfaces ( 35 ,  36 ) being positioned between the guide axis ( 24 ) and a longitudinal axis ( 14 ) of the axial slide ( 12 ).   
     
     
         2 . The diffuser according to  claim 1 , wherein
 the engagement recess ( 25 ) is provided at side of a guide section ( 18 ) of the adjusting fork ( 17 ) facing the axial slide ( 12 ).   
     
     
         3 . The diffuser according to  claim 2 , wherein
 the guide section ( 18 ) is firmly joined to the adjusting fork ( 17 ).   
     
     
         4 . The diffuser according to  claim 1 , wherein
 the lever end ( 28 ) is movably accommodated in the engagement recess ( 25 ).   
     
     
         5 . A turbocharger for an internal combustion engine, comprising a housing ( 2 ) with an exhaust gas duct section ( 3 ) through which exhaust gas can flow to a turbine wheel space in the housing ( 2 ) and wherein a diffuser ( 10 ) for changing the admission of exhaust gas to the turbine wheel space is provided in the exhaust gas duct section ( 3 ), the diffuser ( 10 ) supporting an axial slide ( 12 ), and an adjusting device ( 16 ) for positioning the axial slide ( 12 ), the adjusting device ( 16 ) comprising an adjusting fork ( 17 ) having an opening ( 23 ) with a guide axis ( 24 ) for the accommodation of a guide element ( 19 ), the adjusting device ( 16 ) further comprising an adjusting lever ( 20 ) with a lever end ( 28 ), the adjusting fork ( 17 ) having at least one contact surface ( 35 ,  36 ), in body contact with the axial slide ( 12 ), the adjusting fork ( 17 ) further having an engagement recess ( 25 ) for the accommodation of the lever end ( 28 ), the engagement recess ( 25 ) with the lever end ( 28 ) being positioned between the guide axis ( 24 ) and a longitudinal axis ( 14 ) of the axial slide ( 12 ) 
     
     
         7 . The turbocharger according to  claim 5 , wherein the guide element ( 19 ) is supported in a contoured sleeve ( 13 ) on the side remote from the second spiral passage ( 5 ) and in the exhaust gas guide section ( 3 ) on the side facing the second spiral passage ( 5 ). 
     
     
         8 . The turbocharger according to  claim 5 , wherein the guide element ( 19 ) and the opening ( 23 ) are cylindrical. 
     
     
         9 . The turbocharger according to  claim 5 , wherein the adjusting fork ( 17 ) and the axial slide ( 12 ) have a first body contact and a second body contact, the first body contact and the second body contact being arranged symmetrically with respect to the guide axis ( 24 ) of the guide element ( 19 ).