Abstract: A foil bearing system includes a journal member with an internal groove and a foil arrangement. The foil arrangement includes at least one biasing foil and a top foil insert member. The at least one biasing foil is received between the journal member and the shaft in a radial direction with respect to the axis. The top foil insert member includes a top foil and a spine insert. The top foil includes an arcuate portion that is disposed between the at least one biasing foil and the shaft in the radial direction and that extends in a circumferential direction about the axis. The top foil includes an end that extends from the arcuate portion. The spine insert is received within the internal groove, and the spine insert is fixedly attached to the end of the top foil.

Abstract: An assembly can include a shaft that includes threads and a free end that includes a shaft drive feature; a compressor wheel that includes a compressor wheel drive feature and a through bore that receives the shaft; and a nut that includes threads that mate the threads of the shaft.

Abstract: A turbocharger system can include a housing that includes a through bore, a plurality of lubricant bores, a plurality of lubricant bore to through bore openings and a recessed compressor-side surface that defines in part a passage that fluidly couples at least two of the lubricant bores; a rolling element bearing unit disposed at least in part in the through bore of the housing; and, a plate that covers at least a portion of the recessed compressor-side surface of the housing.

Abstract: An assembly can include a turbocharger center housing that includes a through bore that extends between a compressor end and a turbine end of the turbocharger center housing where the through bore includes a sleeve mating surface; and a sleeve positioned at least in part in the through bore of the turbocharger center housing where the sleeve includes an outer mating surface, an inner compressor side bearing lubricant film formation surface disposed at a first radius, an inner turbine side bearing lubricant film formation surface disposed at a second radius, and a surface between the inner compressor side bearing lubricant film formation surface and the inner turbine side bearing lubricant film formation surface that includes a third radius that is less than the first radius and less than the second radius and where outer mating surface of the sleeve contacts the sleeve mating surface of the turbocharger center.

Abstract: An assembly can include a turbocharger center housing that includes a through bore and a counterbore positioned between a compressor end and a turbine end of the through bore where the through bore includes a sleeve mating surface positioned between the compressor end and the counterbore and a turbine side bearing lubricant film formation surface positioned between the counterbore and the turbine end; and a sleeve positioned at least in part in the through bore of the turbocharger center housing between the compressor end and the counterbore where the sleeve includes a locating flange and an axial extension that extends from the locating flange where the axial extension includes an outer mating surface, an inner compressor side bearing lubricant film formation surface, a compressor side axially facing spacer surface and a turbine side axially facing spacer surface.

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: An assembly can include a shaft that includes threads and a free end that includes a shaft drive feature; a compressor wheel that includes a compressor wheel drive feature and a through bore that receives the shaft; and a nut that includes threads that mate the threads of the shaft.

Abstract: A turbocharger system can include a housing that includes a through bore, a plurality of lubricant bores, a plurality of lubricant bore to through bore openings and a recessed compressor-side surface that defines in part a passage that fluidly couples at least two of the lubricant bores; a rolling element bearing unit disposed at least in part in the through bore of the housing; and, a plate that covers at least a portion of the recessed compressor-side surface of the housing.

Abstract: A turbocharger bearing assembly can include a spacer that includes an axial through bore, a compressor side surface and a turbine side surface; a compressor side rolling element bearing that includes an outer race surface that faces the compressor side surface of the spacer; a turbine side rolling element bearing that includes an outer race surface that faces the turbine side surface of the spacer; and a spring seated between a first end cap disposed at least in part in the axial through bore of the spacer and a second end cap disposed at least in part in the axial through bore of the spacer where the spring biases an axially facing surface of the first end cap against the outer race surface of the compressor side rolling element bearing and where the spring biases an axially facing surface of the second end cap against the outer race surface of the turbine side rolling element bearing.

Abstract: An assembly can include a turbocharger center housing that includes a through bore that extends between a compressor end and a turbine end of the turbocharger center housing where the through bore includes a sleeve mating surface; and a sleeve positioned at least in part in the through bore of the turbocharger center housing where the sleeve includes an outer mating surface, an inner compressor side bearing lubricant film formation surface disposed at a first radius, an inner turbine side bearing lubricant film formation surface disposed at a second radius, and a surface between the inner compressor side bearing lubricant film formation surface and the inner turbine side bearing lubricant film formation surface that includes a third radius that is less than the first radius and less than the second radius and where outer mating surface of the sleeve contacts the sleeve mating surface of the turbocharger center.

Abstract: An assembly can include a turbocharger center housing that includes a through bore and a counterbore positioned between a compressor end and a turbine end of the through bore where the through bore includes a sleeve mating surface positioned between the compressor end and the counterbore and a turbine side bearing lubricant film formation surface positioned between the counterbore and the turbine end; and a sleeve positioned at least in part in the through bore of the turbocharger center housing between the compressor end and the counterbore where the sleeve includes a locating flange and an axial extension that extends from the locating flange where the axial extension includes an outer mating surface, an inner compressor side bearing lubricant film formation surface, a compressor side axially facing spacer surface and a turbine side axially facing spacer surface.

Abstract: A turbocharger bearing assembly can include a spacer that includes an axial through bore, a compressor side surface and a turbine side surface; a compressor side rolling element bearing that includes an outer race surface that faces the compressor side surface of the spacer; a turbine side rolling element bearing that includes an outer race surface that faces the turbine side surface of the spacer; and a spring seated between a first end cap disposed at least in part in the axial through bore of the spacer and a second end cap disposed at least in part in the axial through bore of the spacer where the spring biases an axially facing surface of the first end cap against the outer race surface of the compressor side rolling element bearing and where the spring biases an axially facing surface of the second end cap against the outer race surface of the turbine side rolling element bearing.

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.

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. Various other examples of devices, assemblies, systems, methods, etc., are also disclosed.

Abstract: A turbocharger bearing assembly can include a compressor side bearing; a turbine side bearing; and a spacer configured to axially space the compressor side bearing and the turbine side bearing where the spacer includes lubricant passages to direct lubricant to spacer-bearing interfaces and where the spacer optionally includes a spring disposed in a central through bore to load the bearings. Various other examples of devices, assemblies, systems, methods, etc., are also disclosed.

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.

Abstract: A variable-nozzle turbocharger includes a turbine housing and a center housing, and a generally annular nozzle ring and an array of vanes rotatably mounted to the nozzle ring such that the vanes are rotatably adjustable for regulating exhaust gas flow to the turbine wheel. An elastically deformable member is disposed between a radially inwardly facing surface of the nozzle ring and a radially outwardly facing surface of the center housing, the elastically deformable member having a radially inner surface contacting the radially outwardly facing surface of the center housing and having a radially outer surface contacting the radially inwardly facing surface of the nozzle ring so as to radially center the nozzle ring relative to the center housing.

Abstract: A variable-nozzle turbocharger includes a cartridge containing a variable vane mechanism connected between the center housing and the turbine housing. The cartridge comprises an annular nozzle ring supporting an array of rotatable vanes, an insert having a tubular portion sealingly received into the bore of the turbine housing and having a nozzle portion extending radially out from one end of the tubular portion and being axially spaced from the nozzle ring with the vanes therebetween, a plurality of spacers connected between the nozzle portion of the insert and the nozzle ring, and an annular retainer ring fastened to the center housing so as to capture the nozzle ring between the retainer ring and the center housing. The retainer ring is formed as a separate part from the insert ring and is mechanically and thermally decoupled from the insert.

Abstract: A turbocharger bearing assembly can include a compressor side bearing; a turbine side bearing; and a spacer configured to axially space the compressor side bearing and the turbine side bearing where the spacer includes lubricant passages to direct lubricant to spacer-bearing interfaces and where the spacer optionally includes a spring disposed in a central through bore to load the bearings. Various other examples of devices, assemblies, systems, methods, etc., are also disclosed.

Abstract: A variable-nozzle turbocharger includes a turbine housing and a center housing, and a generally annular nozzle ring and an array of vanes rotatably mounted to the nozzle ring such that the vanes are rotatably adjustable for regulating exhaust gas flow to the turbine wheel. An elastically deformable member is disposed between a radially inwardly facing surface of the nozzle ring and a radially outwardly facing surface of the center housing, the elastically deformable member having a radially inner surface contacting the radially outwardly facing surface of the center housing and having a radially outer surface contacting the radially inwardly facing surface of the nozzle ring so as to radially center the nozzle ring relative to the center housing.