Turbocharger bearing assembly

An assembly comprising:

• a turbocharger center housing that comprises a through bore that extends between a compressor end and a turbine end of the turbocharger center housing wherein the through bore comprises a sleeve mating surface;
• and
• a sleeve positioned at least in part in the through bore of the turbocharger center housing wherein the sleeve comprises 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 comprises a third radius that is less than the first radius and less than the second radius, wherein the outer mating surface of the sleeve contacts the sleeve mating surface of the turbocharger center housing, wherein the sleeve comprises a compressor side lubricant hole and a turbine side lubricant hole, and wherein an axial span between the compressor side lubricant hole and the turbine side lubricant hole is less than an axial length of a lubricant gallery recess of the turbocharger center housing that is recessed radially outwardly from the sleeve mating surface.

An assembly comprising:

• a turbocharger center housing that comprises a through bore that extends between a compressor end and a turbine end of the turbocharger center housing and a counterbore disposed at an axial location between the compressor end and the turbine end of the through bore of the turbocharger center housing wherein the through bore comprises a sleeve mating surface and wherein the counterbore comprises a segmented counterbore wherein each segment spans a respective azimuthal angle;
• and
• a sleeve positioned at least in part in the through bore of the turbocharger center housing wherein the sleeve comprises 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 comprises a third radius that is less than the first radius and less than the second radius and wherein the outer mating surface of the sleeve contacts the sleeve mating surface of the turbocharger center housing.