Abstract: An engine system includes an internal combustion engine, at least one turbocharger, and a catalytic treatment device. The engine includes an exhaust manifold system having a main exhaust manifold and a bypass exhaust manifold. A partial-engine bypass valve system is positioned between the engine and the exhaust manifold system. The bypass valve system when placed in a non-bypass position directs all of the engine exhaust gases to the turbine wheel of the turbocharger, and after passing through the turbine wheel the gases proceed to the catalytic device. In a bypass position of the bypass valve system, a bypass portion of the total exhaust gases is made to bypass the turbine wheel and proceed to the catalytic device, while the remainder first passes through the turbine wheel before going to the catalytic device.

Abstract: An assembly for an exhaust bypass valve of a two-stage turbocharger can include a first turbocharger stage; a second turbocharger stage; an exhaust bypass valve that includes an open state and a closed state; an actuator; and a linkage mechanism that links the exhaust bypass valve to the actuator where the linkage mechanism includes a spring-biased linkage with a preset load where, in the closed state of the exhaust bypass valve, an axial length of the spring-biased linkage increases responsive to application of a load by the actuator that exceeds the preset load.

Abstract: An engine system includes an internal combustion engine, at least one turbocharger, and a catalytic treatment device. The engine includes an exhaust manifold system having a main exhaust manifold and a bypass exhaust manifold. A partial-engine bypass valve system is positioned between the engine and the exhaust manifold system. The bypass valve system when placed in a non-bypass position directs all of the engine exhaust gases to the turbine wheel of the turbocharger, and after passing through the turbine wheel the gases proceed to the catalytic device. In a bypass position of the bypass valve system, a bypass portion of the total exhaust gases is made to bypass the turbine wheel and proceed to the catalytic device, while the remainder first passes through the turbine wheel before going to the catalytic device.

Abstract: An assembly can include a turbine housing that includes a bore, a wastegate seat, wastegate passages that extend to the wastegate seat and a divider wall disposed between the wastegate passages where the divider wall includes a divider wall surface; a rotatable wastegate shaft configured for receipt by the bore; a wastegate arm extending from the wastegate shaft; and a wastegate plug extending from the wastegate arm where the wastegate plug includes a contact portion that contacts the wastegate seat to cover the wastegate passages in a closed state and a mesh that contacts the divider wall surface in the closed state.

Abstract: An assembly can include a turbine housing that includes a bore, a wastegate seat, wastegate passages that extend to the wastegate seat and a divider wall disposed between the wastegate passages where the divider wall includes a divider wall surface; a rotatable wastegate shaft configured for receipt by the bore; a wastegate arm extending from the wastegate shaft; and a wastegate plug extending from the wastegate arm where the wastegate plug includes a contact portion that contacts the wastegate seat to cover the wastegate passages in a closed state and a mesh that contacts the divider wall surface in the closed state.

Abstract: A turbocharger turbine wastegate assembly includes a turbine housing that includes a wastegate seat and a bore; a bushing with a stepped bore that includes an axial face; a wastegate that includes a shaft, a plug and an arm, where the shaft includes an end portion, a first axial face, a journal portion, a second axial face and a shoulder portion, where the first axial face is defined at least in part by an end portion diameter and a journal portion diameter, and where the second axial face is defined at least in part by the journal portion diameter and a shoulder portion diameter; a mesh spacer disposed radially about an axial length of the end portion of the shaft between the axial face of the stepped bore of the bushing and the first axial face of the shaft; and a control arm connected to the end portion of the shaft where an axial length of the bushing is disposed between the mesh spacer and the control arm.

Abstract: A method includes positioning a bushing in a bore of a turbine housing; positioning a shaft of a wastegate in a bore of the bushing where the shaft includes a shaft shoulder and a shaft end; applying force to a plug of the wastegate to substantially center the plug with respect to a wastegate seat of the turbine housing; positioning a resilient metal wire mesh ring at least in part in the bore of the bushing and between the shaft shoulder and the shaft end; encasing the ring into the bore of the bushing; and fixing a control arm to the shaft.

Abstract: An assembly for an exhaust bypass valve of a two-stage turbocharger can include a first turbocharger stage; a second turbocharger stage; an exhaust bypass valve that includes an open state and a closed state; and a linkage mechanism that links the exhaust bypass valve to an actuator where the linkage mechanism includes a locked state for the closed state of the exhaust bypass valve.

Abstract: A method can include providing a turbocharger housing that includes a bore; providing a spacer; providing a shaft and wheel assembly with a first rolling element bearing assembly seated on a first portion of a shaft of the shaft and wheel assembly; providing a second rolling element bearing assembly; interference-fitting the spacer into the bore; inserting a free end of the shaft into the bore and through the spacer; and inserting the second rolling element bearing assembly into the bore and seating the second rolling element bearing assembly on a second portion of the shaft such that the spacer is disposed intermediate the first portion of the shaft and the second portion of the shaft.

Abstract: A turbocharger includes a variable turbine nozzle defined between a nozzle ring and a pipe flange, and having a plurality of circumferentially spaced vanes rotatably mounted on the nozzle ring such that the vanes are pivotable. Each vane includes an airfoil section and a disk section rigidly affixed to an end of the airfoil section, the disk section being disposed against a face of the pipe flange, each disk section having a plurality of perforations extending axially therethrough. The pipe flange has a corresponding number of holes for each disk section of the vanes, the holes being positioned such that as each vane is rotated the perforations in the disk sections and the holes in the pipe flange of the insert become aligned in some positions of the vanes, allowing exhaust gas to pass between the nozzle and a space on an opposite side of the pipe flange from the nozzle.

Abstract: An assembly for an exhaust bypass valve of a two-stage turbocharger can include a first turbocharger stage; a second turbocharger stage; an exhaust bypass valve that includes an open state and a closed state; an actuator; and a linkage mechanism that links the exhaust bypass valve to the actuator where the linkage mechanism includes a spring-biased linkage with a preset load where, in the closed state of the exhaust bypass valve, an axial length of the spring-biased linkage increases responsive to application of a load by the actuator that exceeds the preset load.

Abstract: A turbocharger turbine wastegate assembly includes a turbine housing that includes a wastegate seat and a bore; a bushing with a stepped bore that includes an axial face; a wastegate that includes a shaft, a plug and an arm, where the shaft includes an end portion, a first axial face, a journal portion, a second axial face and a shoulder portion, where the first axial face is defined at least in part by an end portion diameter and a journal portion diameter, and where the second axial face is defined at least in part by the journal portion diameter and a shoulder portion diameter; a mesh spacer disposed radially about an axial length of the end portion of the shaft between the axial face of the stepped bore of the bushing and the first axial face of the shaft; and a control arm connected to the end portion of the shaft where an axial length of the bushing is disposed between the mesh spacer and the control arm.

Abstract: A method can include positioning a bushing in a bore of a turbine housing; positioning a shaft of a wastegate in a bore of the bushing where the shaft includes a shaft shoulder and a shaft end; applying force to a plug of the wastegate to substantially center the plug with respect to a wastegate seat of the turbine housing; positioning a ring at least in part in the bore of the bushing and between the shaft shoulder and the shaft end; and fixing the ring to the bushing.

Abstract: A centrifugal compressor for a turbocharger includes an inlet-adjustment mechanism in an air inlet for the compressor, operable to move between an open position and a closed position in the air inlet. The inlet-adjustment mechanism includes a variable-geometry conical mechanism comprising a plurality of vanes that in the closed position collectively form a frusto-conical inlet member having a trailing edge inner diameter that is smaller than an inner diameter of the shroud surface of the compressor housing at the inducer portion of the compressor wheel such that an effective diameter of the air inlet at the inducer portion is determined by the trailing edge inner diameter of the variable-geometry conical mechanism. The vanes in the open position are pivoted radially outwardly so as to increase the trailing edge inner diameter of the inlet member and thereby increase the effective diameter of the air inlet at the inducer portion.

Abstract: A centrifugal compressor for a turbocharger includes an inlet-adjustment mechanism in an air inlet for the compressor, operable to move between an open position and a closed position in the air inlet. The inlet-adjustment mechanism includes a variable-geometry conduit comprising a plurality of vanes that in the closed position collectively form a converging inlet member having a trailing edge inner diameter that is smaller than an inner diameter of the shroud surface of the compressor housing at the inducer portion of the compressor wheel such that an effective diameter of the air inlet at the inducer portion is determined by the trailing edge inner diameter of the variable-geometry conduit. The vanes in the open position are pivoted radially outwardly so as to increase the trailing edge inner diameter of the inlet member and thereby increase the effective diameter of the air inlet at the inducer portion.

Abstract: An assembly for an exhaust bypass valve of a two-stage turbocharger can include a first turbocharger stage; a second turbocharger stage; an exhaust bypass valve that includes an open state and a closed state; and a linkage mechanism that links the exhaust bypass valve to an actuator where the linkage mechanism includes a locked state for the closed state of the exhaust bypass valve.

Abstract: A turbocharger includes a variable turbine nozzle defined between a nozzle ring and a pipe flange, and having a plurality of circumferentially spaced vanes rotatably mounted on the nozzle ring such that the vanes are pivotable. Each vane includes an airfoil section and a disk section rigidly affixed to an end of the airfoil section, the disk section being disposed against a face of the pipe flange, each disk section having a plurality of perforations extending axially therethrough. The pipe flange has a corresponding number of holes for each disk section of the vanes, the holes being positioned such that as each vane is rotated the perforations in the disk sections and the holes in the pipe flange of the insert become aligned in some positions of the vanes, allowing exhaust gas to pass between the nozzle and a space on an opposite side of the pipe flange from the nozzle.

Abstract: A centrifugal compressor for a turbocharger includes an inlet-adjustment mechanism in an air inlet for the compressor, operable to move between an open position and a closed position in the air inlet. The inlet-adjustment mechanism includes a variable-geometry conduit comprising a plurality of vanes that in the closed position collectively form a converging inlet member having a trailing edge inner diameter that is smaller than an inner diameter of the shroud surface of the compressor housing at the inducer portion of the compressor wheel such that an effective diameter of the air inlet at the inducer portion is determined by the trailing edge inner diameter of the variable-geometry conduit. The vanes in the open position are pivoted radially outwardly so as to increase the trailing edge inner diameter of the inlet member and thereby increase the effective diameter of the air inlet at the inducer portion.

Abstract: A centrifugal compressor for a turbocharger includes an inlet-adjustment mechanism in an air inlet for the compressor, operable to move between an open position and a closed position in the air inlet. The inlet-adjustment mechanism includes a variable-geometry conical mechanism comprising a plurality of vanes that in the closed position collectively form a frusto-conical inlet member having a trailing edge inner diameter that is smaller than an inner diameter of the shroud surface of the compressor housing at the inducer portion of the compressor wheel such that an effective diameter of the air inlet at the inducer portion is determined by the trailing edge inner diameter of the variable-geometry conical mechanism. The vanes in the open position are pivoted radially outwardly so as to increase the trailing edge inner diameter of the inlet member and thereby increase the effective diameter of the air inlet at the inducer portion.

Abstract: An assembly for a turbocharger can include a locating washer having an axis and a perimeter that includes a chord segment defined by an apothem measured from the axis; a bearing assembly that includes an outer race having an axis and a perimeter that includes a chord segment defined by an apothem measured from the axis; and a housing that includes a bore for receipt of the bearing assembly and a recess for receipt of the locating washer to space apart the axes of the locating washer and the outer race by a distance greater than the sum of the apothems that provides for contact between the chord segments upon rotation of at least one of the locating washer in the recess and the outer race in the bore. Various other examples of devices, assemblies, systems, methods, etc., are also disclosed.