초록 ▼

The flow path of exhaust gas to the turbine wheel (70) of a twin volute turbocharger is influenced by the shape and size of the nozzle formed by the shape (22) of the divider wall (21) and the shape of the flow passage determined by the walls (85, 86) of the turbine housing. By moving the walls (85,

The flow path of exhaust gas to the turbine wheel (70) of a twin volute turbocharger is influenced by the shape and size of the nozzle formed by the shape (22) of the divider wall (21) and the shape of the flow passage determined by the walls (85, 86) of the turbine housing. By moving the walls (85, 86) toward, or away from the divider wall, the flow of exhaust gas through the nozzle, to the turbine wheel (70) can be modulated, which thus modulates the turbocharger boost pressure. The invention also applies to single volute turbines.

대표청구항 ▼

1. A turbocharger comprising: a turbine housing (2) including at least one volute (47, 48, 49),a turbine wheel (70) carried within the turbine housing and adapted to being driven by exhaust gas,a transition area (39) where exhaust from the volute(s) is transmitted to the turbine wheel,first and seco

1. A turbocharger comprising: a turbine housing (2) including at least one volute (47, 48, 49),a turbine wheel (70) carried within the turbine housing and adapted to being driven by exhaust gas,a transition area (39) where exhaust from the volute(s) is transmitted to the turbine wheel,first and second cylinders (81) with end faces (58, 59) with contours (85, 86) defining said transition area, wherein said first contour (85) is part of said first cylinder end face (58), generally coaxial and concentric to the turbine wheel and movable parallel to the axis of rotation of the turbine wheel, and wherein said second contour (86) is part of a said second cylinder end face (59), generally coaxial and concentric to the turbine wheel and movable parallel to an axis of rotation of the turbine wheel; anddrive means for simultaneously moving said first and second cylinder end faces towards each other. 2. The turbocharger as in claim 1, wherein said turbine housing includes first and second volutes (48, 49) separated by a divider wall (21). 3. The turbocharger as in claim 1, wherein said turbine housing includes a single volute (47). 4. The turbocharger as in claim 1, wherein said transition area (39) narrows from said volute towards said turbine wheel. 5. The turbocharger as in claim 1, further including drive means for moving said first and second cylinder end faces apart from each other. 6. The turbocharger as in claim 1, wherein said drive means is selected from pneumatic, hydraulic, and electro-mechanical. 7. A turbocharger comprising: a turbine housing including one or more volutes (47, 48, 49) separated by a divider wall (21),a turbine wheel carried within the turbine housing and extracting energy from the exhaust gas,a transition area where exhaust from the twin volutes is transmitted to the turbine wheel,first and second cylinders (81) with end faces (58, 59) with contours (85, 86) defining said transition area,wherein said first contour (85) is part of a first cylinder end face (58), generally concentric to the turbine wheel and movable parallel to an axis of rotation of the turbine wheel, and wherein said second contour (86) is part of a cylinder end face (59), generally concentric to the turbine wheel and movable parallel to an axis of rotation of the turbine wheel; anddrive means for independently moving said first and second cylinder end faces towards each other. 8. A turbocharger comprising: a turbine housing including first and second volutes (49, 49) separated by a divider wall (21),a turbine wheel carried within the turbine housing and extracting energy from the exhaust gas,a transition area where exhaust from the twin volutes is respectively transmitted to the turbine wheel,first and second cylinder (81) end faces (58, 59) with contours (85, 86) defining said transition area, wherein said first contour (85) is part of a first cylinder end face (58), generally concentric to the turbine wheel and rotatable about the turbocharger axis, and wherein said second contour (86) is part of a cylinder end face (59), generally concentric to the turbine wheel and rotatable about the turbocharger axis;wherein contoured surfaces of the turbine housing define a nozzle-like transition area between volute and turbine wheel having a spiral shape cooperating with the spiral shape of the divider wall, andwherein rotating said first and second cylinder end faces (58, 59) about said turbocharger axis changes the clearance between cylinder end faces and said divider wall. 9. A turbocharger comprising: a turbine housing including first and second volutes (48, 49) separated by a divider wall (21),a turbine wheel carried within the turbine housing and extracting energy from the exhaust gas,a transition area where exhaust from the twin volutes is respectively transmitted to the turbine wheel,wherein the inner diameter (120) of said divider wall is spiral shaped,wherein said divider wall is mounted for rotating about the turbocharger axis,wherein contoured surfaces of the turbine housing define a nozzle-like transition area between volute and turbine wheel having a spiral shape cooperating with the spiral shape of the divider wall, andwherein rotating said divider wall about said turbocharger axis changes the clearance between said spiral shapes.