Abstract: A process for cold working of the inner surface of a bore in a centrifugal compressor wheel along only a fractional portion of the bore length (i.e., along less than a full axial length of the bore), thereby creating a zone of compressive residual hoop stress in the metal surrounding the bore where the wheel needs the beneficial residual stress. The process purposefully avoids cold working of the bore at locations adjacent to high-stress areas and features of the wheel, where cold working in such locations could negatively impact the wheel's overall life.

Abstract: A twin-vaned nozzle ring for a turbine nozzle of a turbocharger nozzle ring is made by assembling the nozzle ring from three separately formed parts. A center part includes a first ring of circumferentially spaced first vanes and a second ring of circumferentially spaced second vanes, the first and second rings being axially spaced and integrally joined to each other. The first vanes are circumferentially offset from the second vanes, and exits from the first vane passages are radially aligned with and circumferentially interleaved with exits from the second vane passages. First and second side walls are provided as separate parts. Finally, the first side wall is joined to a distal or outer face of the first ring, and the second side wall is joined to a distal face of the second ring to complete the assembly.

Abstract: A turbocharger has a meridionally divided turbine housing defining a first scroll and a first nozzle, and a second scroll and a second nozzle. The first and second nozzles are divided from each other by a shroud plate mounted within the nozzle, for isolating the exhaust gas streams flowing through the two nozzles from each other. A plurality of first vanes are disposed in the first nozzle, and plurality of second vanes are disposed in the second nozzle. A nozzle ring rotatably supports a plurality of vane shafts that extend across the first and second nozzles, passing through openings in the shroud plate. A first vane and a second vane are affixed to each vane shaft. Rotation of the vane shafts causes the first vanes and the second vanes to pivot for regulating the two streams of exhaust gas flowing through the first and second nozzles.

Abstract: A turbocharger has a turbine housing scroll that is meridionally divided into first and second scrolls. A nozzle ring disposed in the turbine nozzle has an array of circumferentially spaced first vanes and an array of circumferentially spaced second vanes. The first vane passages between first vanes are configured to blow exhaust gas onto the turbine blade leading edges. Likewise, the second vane passages are configured to blow exhaust gas on the turbine blade leading edges. The first and second vanes are circumferentially staggered relative to each other such that the turbine blade leading edges receive exhaust gas from the first and second blade passages in interleaved fashion about a circumference of the turbine wheel.

Abstract: A turbocharger has a meridionally divided turbine housing defining a first scroll and a first nozzle, and a second scroll and a second nozzle. The first and second nozzles are divided from each other by a shroud plate mounted within the nozzle, for isolating the exhaust gas streams flowing through the two nozzles from each other. A plurality of circumferentially spaced vanes are rotatably mounted at a radially inner side of the nozzles. Leading-edge portions of the vanes are slotted to receive the shroud plate when the vanes are pivoted open. Trailing-edge portions of the vanes are unslotted. A radially inner periphery of the shroud plate includes cutouts for abutting the trailing-edge portions of the vanes in the closed position, and includes contour portions for influencing a flow separation ratio of the turbine.

Abstract: A process for cold working of the inner surface of a bore in a centrifugal compressor wheel along only a fractional portion of the bore length (i.e., along less than a full axial length of the bore), thereby creating a zone of compressive residual hoop stress in the metal surrounding the bore where the wheel needs the beneficial residual stress. The process purposefully avoids cold working of the bore at locations adjacent to high-stress areas and features of the wheel, where cold working in such locations could negatively impact the wheel's overall life.

Abstract: A turbocharger has a turbine housing scroll that is meridionally divided into first and second scrolls. A nozzle ring disposed in the turbine nozzle has an array of circumferentially spaced first vanes and an array of circumferentially spaced second vanes. The first vane passages between first vanes are configured to blow exhaust gas onto the turbine blade leading edges. Likewise, the second vane passages are configured to blow exhaust gas on the turbine blade leading edges. The first and second vanes are circumferentially staggered relative to each other such that the turbine blade leading edges receive exhaust gas from the first and second blade passages in interleaved fashion about a circumference of the turbine wheel.

Abstract: A twin-vaned nozzle ring for a turbine nozzle of a turbocharger nozzle ring is made by assembling the nozzle ring from three separately formed parts. A center part includes a first ring of circumferentially spaced first vanes and a second ring of circumferentially spaced second vanes, the first and second rings being axially spaced and integrally joined to each other. The first vanes are circumferentially offset from the second vanes, and exits from the first vane passages are radially aligned with and circumferentially interleaved with exits from the second vane passages. First and second side walls are provided as separate parts. Finally, the first side wall is joined to a distal or outer face of the first ring, and the second side wall is joined to a distal face of the second ring to complete the assembly.

Abstract: A turbocharger has a meridionally divided turbine housing defining a first scroll and a first nozzle, and a second scroll and a second nozzle. The first and second nozzles are divided from each other by a shroud plate mounted within the nozzle, for isolating the exhaust gas streams flowing through the two nozzles from each other. A plurality of first vanes are disposed in the first nozzle, and plurality of second vanes are disposed in the second nozzle. A nozzle ring rotatably supports a plurality of vane shafts that extend across the first and second nozzles, passing through openings in the shroud plate. A first vane and a second vane are affixed to each vane shaft. Rotation of the vane shafts causes the first vanes and the second vanes to pivot for regulating the two streams of exhaust gas flowing through the first and second nozzles.

Abstract: A turbocharger has a meridionally divided turbine housing defining a first scroll and a first nozzle, and a second scroll and a second nozzle. The first and second nozzles are divided from each other by a shroud plate mounted within the nozzle, for isolating the exhaust gas streams flowing through the two nozzles from each other. A plurality of circumferentially spaced vanes are rotatably mounted at a radially inner side of the nozzles. Leading-edge portions of the vanes are slotted to receive the shroud plate when the vanes are pivoted open. Trailing-edge portions of the vanes are unslotted. A radially inner periphery of the shroud plate includes cutouts for abutting the trailing-edge portions of the vanes in the closed position, and includes contour portions for influencing a flow separation ratio of the turbine.