Abstract: A turbocharger for internal combustion engines, having a heat shield disposed between a turbine housing and center housing of the turbocharger for shielding the center housing from exhaust gases passing through the turbine. The heat shield in one embodiment is centered on a generally conical surface of the center housing, by engagement between the conical surface and a centering portion of the heat shield. In another embodiment, the heat shield has a generally conical portion that is non-axisymmetric, having a plurality of radially enlarged lobes that engage a radially inwardly facing surface of the turbine housing for centering the heat shield.

Abstract: A sliding piston cartridge (50) for a turbocharger (20) that is insertable into a bore (44) in the turbine housing (38) as a unit and that includes all of the components of a sliding piston type variable nozzle. The sliding piston cartridge comprises a carrier (52) having a tubular portion that interfaces with the bore of the turbine housing. A sliding piston (62) is disposed within the carrier and makes sliding contact therewith. Vanes (58) are mounted on or formed as a part of the carrier at its upstream end, the vanes extending across a turbine nozzle. The piston slides between a closed position and an open position relative to the carrier. The tubular portion of the carrier can include openings (66) that are progressively uncovered by the piston as it moves toward the open position, to allow additional flow to enter the turbine wheel without passing through the vanes.

Abstract: A turbine assembly for a turbocharger includes a variable nozzle formed by a sliding half-collar piston. A first-stage nozzle has a plurality of first vanes supported by a first nozzle ring and extending axially therefrom. A second-stage nozzle has a second nozzle ring connected to the ends of the first vanes, and a plurality of second vanes extending axially therefrom. The piston regulates flow through the second-stage nozzle, while the first-stage nozzle remains open when the piston is fully closed. The second nozzle ring at least partially divides the first vanes from the second vanes. The half-collar piston includes recesses that receive the second vanes and only partially surround the girth of each second vane.

Abstract: A method for controlling a variable-geometry turbine (24) that includes a variable-geometry mechanism that is movable between a fully closed position closing a relatively greater portion of the turbine nozzle and a fully open position closing a relatively smaller portion of the nozzle. The turbine (24) further comprises a waste gate (40) movable between a closed position and an open position in which some of the exhaust gas bypasses the turbine (24). At low engine speeds, turbocharger boost us regulated by regulating the position of the wastegate. At high engine speeds, the variable geometry is fully open and the wastegate is opened again. When at medium engine speeds, the variable geometry mechanism is to be moved from its closed position toward its fully open position, the waste gate (40) is in an open position to cause a proportion of the exhaust gas to bypass the turbine (24) and thereby reduce the pressure of the exhaust gas in the chamber.

Abstract: A turbocharger for internal combustion engines, having a heat shield disposed between a turbine housing and center housing of the turbocharger for shielding the center housing from exhaust gases passing through the turbine. The heat shield in one embodiment is centered on a generally conical surface of the center housing, by engagement between the conical surface and a centering portion of the heat shield. In another embodiment, the heat shield has a generally conical portion that is non-axisymmetric, having a plurality of radially enlarged lobes that engage a radially inwardly facing surface of the turbine housing for centering the heat shield.

Abstract: A turbocharger for internal combustion engines, having a heat shield disposed between a turbine housing and center housing of the turbocharger for shielding the center housing from exhaust gases passing through the turbine. The heat shield in one embodiment is centered on a generally conical surface of the center housing, by engagement between the conical surface and a centering portion of the heat shield. In another embodiment, the heat shield has a generally conical portion that is non-axisymmetric, having a plurality of radially enlarged lobes that engage a radially inwardly facing surface of the turbine housing for centering the heat shield.

Abstract: There is described a variable geometry turbine having a sliding element (5) for the control of the section throat of the turbine (1) by sliding movement along an axial direction of a turbine wheel (71). The turbine wheel operates to convert a flow of working fluid into mechanical energy. At least one bypass channel (51) is defined in the sliding element (5). The bypass channel is further connected to a turbine wheel outlet area (79) downstream of the turbine wheel for selectively guiding an excess flow of working fluid past the turbine wheel (71), so as to control the operation of the turbine. A use of the variable geometry turbine with a turbocharger for an engine and a method for controlling such turbine is also described.

Abstract: There is described a variable geometry turbine having a sliding element (5) for the control of the section throat of the turbine (1) by sliding movement along an axial direction of a turbine wheel (71). The turbine wheel operates to convert a flow of working fluid into mechanical energy. At least one bypass channel (51) is defined in the sliding element (5). The bypass channel is further connected to a turbine wheel outlet area (79) downstream of the turbine wheel for selectively guiding an excess flow of working fluid past the turbine wheel (71), so as to control the operation of the turbine. A use of the variable geometry turbine with a turbocharger for an engine and a method for controlling such turbine is also described.

Abstract: A sliding piston cartridge (50) for a turbocharger (20) that is insertable into a bore (44) in the turbine housing (38) as a unit and that includes all of the components of a sliding piston type variable nozzle. The sliding piston cartridge comprises a carrier (52) having a tubular portion that interfaces with the bore of the turbine housing. A sliding piston (62) is disposed within the carrier and makes sliding contact therewith. Vanes (58) are mounted on or formed as a part of the carrier at its upstream end, the vanes extending across a turbine nozzle. The piston slides between a closed position and an open position relative to the carrier. The tubular portion of the carrier can include openings (66) that are progressively uncovered by the piston as it moves toward the open position, to allow additional flow to enter the turbine wheel without passing through the vanes.

Abstract: A turbine assembly for a turbocharger includes a variable nozzle formed by a sliding half-collar piston. A first-stage nozzle has a plurality of first vanes supported by a first nozzle ring and extending axially therefrom. A second-stage nozzle has a second nozzle ring connected to the ends of the first vanes, and a plurality of second vanes extending axially therefrom. The piston regulates flow through the second-stage nozzle, while the first-stage nozzle remains open when the piston is fully closed. The second nozzle ring at least partially divides the first vanes from the second vanes. The half-collar piston includes recesses that receive the second vanes and only partially surround the girth of each second vane.

Abstract: A method for controlling a variable-geometry turbine (24) that includes a variable-geometry mechanism that is movable between a fully closed position closing a relatively greater portion of the turbine nozzle and a fully open position closing a relatively smaller portion of the nozzle. The turbine (24) further comprises a waste gate (40) movable between a closed position and an open position in which some of the exhaust gas bypasses the turbine (24). At low engine speeds, turbocharger boost us regulated by regulating the position of the wastegate. At high engine speeds, the variable geometry is fully open and the wastegate is opened again. When at medium engine speeds, the variable geometry mechanism is to be moved from its closed position toward its fully open position, the waste gate (40) is in an open position to cause a proportion of the exhaust gas to bypass the turbine (24) and thereby reduce the pressure of the exhaust gas in the chamber.