Abstract: A variable-nozzle turbocharger includes a variable-vane mechanism that has an annular nozzle ring supporting an array of rotatable vanes connected to vane arms whose distal ends engage recesses in the radially inner periphery of a rotatable unison ring. Rotation of the unison ring causes the vane arms to pivot about their respective pivot axes at the proximal ends of the arms. The vanes are locked in their fully open position by a locking arrangement that includes locking tongues that extend radially inwardly from the inner periphery of the unison ring and contact the vane arms intermediate their distal and proximal ends.

Abstract: A turbocharger can include a center housing; a bearing disposed in a through bore of the center housing where the through bore of the center housing defines a longitudinal axis; a shaft rotatably supported by the bearing; a compressor wheel operatively coupled to the shaft; a turbine wheel operatively coupled to the shaft; and a turbine housing assembly operatively coupled to the center housing where the turbine housing assembly includes: a turbine housing; and a cartridge that includes a nozzle wall component and a plate component that are spaced axially by spacers, where the nozzle wall component includes spacer bores for the spacers and where the nozzle wall component has a non-circular outer perimeter defined at least in part by arcs where adjacent arcs intersect at intersection points, and where each of the intersection points is radially outwardly from a respective one of the spacer bores.

Abstract: An exhaust gas variable geometry turbine assembly can include a number of pivotable vanes that define throats within an exhaust gas nozzle where each of the pivotable vanes includes a corresponding post, where each of the pivotable vanes is made of a first alloy that includes a first amount of nickel by mass, where each of the corresponding posts is made of a second alloy that includes a second amount of nickel by mass and where the second amount of nickel by mass exceeds the first amount of nickel by mass.

Abstract: A turbocharger having a variable-nozzle turbine formed by pivotable vanes supported by a nozzle ring includes an elastically deformable locator disposed between a radially outwardly facing surface of the center housing and an opposing surface of the nozzle ring. In one embodiment the locator is a metallic ring having a radially undulating waveform shape that repeats a plurality of times about a circumference of the locator. In another embodiment the locator is a metallic ring having a C-shaped cross-section in a radial-axial plane. In still another embodiment the locator is a metallic ring having an S-shaped cross-section in a radial-axial plane. In a further embodiment the locator is a plurality of circumferentially spaced, radial locator pins affixed in the center housing and received in radial slots formed in the nozzle ring, the pins restraining the nozzle ring circumferentially and axially but allowing thermal expansion of the nozzle ring.

Abstract: A turbocharger having a variable-nozzle turbine formed by pivotable vanes supported by a nozzle ring includes an elastically deformable locator disposed between a radially outwardly facing surface of the center housing and an opposing surface of the nozzle ring. In one embodiment the locator is a metallic ring having a radially undulating waveform shape that repeats a plurality of times about a circumference of the locator. In another embodiment the locator is a metallic ring having a C-shaped cross-section in a radial-axial plane. In still another embodiment the locator is a metallic ring having an S-shaped cross-section in a radial-axial plane. In a further embodiment the locator is a plurality of circumferentially spaced, radial locator pins affixed in the center housing and received in radial slots formed in the nozzle ring, the pins restraining the nozzle ring circumferentially and axially but allowing thermal expansion of the nozzle ring.

Abstract: An exhaust gas variable geometry turbine assembly can include a number of pivotable vanes that define throats within an exhaust gas nozzle where each of the pivotable vanes includes a corresponding post, where each of the pivotable vanes is made of a first alloy that includes a first amount of nickel by mass, where each of the corresponding posts is made of a second alloy that includes a second amount of nickel by mass and where the second amount of nickel by mass exceeds the first amount of nickel by mass.