Turbocharger bearing assembly

1. An assembly comprising:

a turbocharger center housing that comprises a through bore and a counterbore positioned between a compressor end and a turbine end of the through bore wherein the through bore comprises 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;

a turbine side bearing that is received at least in part between the counterbore and the turbine end to define a lubricant film clearance wherein the lubricant film clearance is defined by the difference between an outer radius of an outer surface of an outer race of the turbine side bearing and an inner radius of the turbine side bearing lubricant film formation surface of the through bore of the turbocharger center housing; and

a sleeve positioned at least in part in the through bore of the turbocharger center housing between the compressor end and the counterbore wherein the sleeve comprises a locating flange and an axial extension that extends from the locating flange wherein the axial extension comprises an outer mating surface that contacts the sleeve mating surface of the turbocharger center housing, an inner compressor side bearing lubricant film formation surface, a compressor side axially facing spacer surface and a turbine side axially facing spacer surface wherein the outer race of the turbine side bearing is axially located at least in part by the turbine side axially facing spacer surface.

2. The assembly of claim 1 further comprising a compressor side bearing that comprises an outer race and rolling elements wherein the outer race is received at least in part by the sleeve to form a lubricant film clearance between the outer race and the inner compressor side bearing lubricant film formation surface of the sleeve.

3. The assembly of claim 1 further comprising a shaft and turbine wheel assembly wherein the turbine side bearing is fit to the shaft.

4. The assembly of claim 1 further comprising a spring positioned at least in part between the compressor side axially facing spacer surface and the turbine side axially facing spacer surface of the sleeve.

5. The assembly of claim 1 further comprising at least one bolt that bolts the sleeve to the housing.

6. The assembly of claim 1 further comprising a bolt that contacts the locating flange and that contacts the housing to secure the sleeve to the housing.

7. The assembly of claim 1 wherein the sleeve mating surface of the through bore of the housing and the outer mating surface of the sleeve radially position the sleeve in the through bore of the housing.

8. The assembly of claim 1 wherein the housing comprises lubricant passages that direct lubricant to a first lubricant opening disposed between the compressor end and the counterbore and to a second lubricant opening disposed between the counterbore and the turbine end.

9. The assembly of claim 1 wherein the sleeve mating surface comprises a first sleeve mating surface and further comprising a second sleeve mating surface.

10. The assembly of claim 9 further comprising lubricant well surfaces disposed between the first sleeve mating surface and the second sleeve mating surface.

11. The assembly of claim 1 further comprising a compressor side bearing, a shaft and a turbine wheel, the turbine wheel welded to the shaft and the shaft rotatably supported by the compressor side bearing and the turbine side bearing.

12. The assembly of claim 11 further comprising a compressor wheel attached to the shaft.

13. The assembly of claim 1 further comprising a compressor side bearing that comprises an outer race, rolling elements and an inner race wherein the outer race is received at least in part by the sleeve.

14. The assembly of claim 13 wherein the turbine side bearing comprises rolling elements and an inner race wherein the outer race is received at least part between the counterbore and the turbine end.

15. An assembly comprising:

a turbocharger center housing that comprises a through bore and a counterbore positioned between a compressor end and a turbine end of the through bore wherein the through bore comprises 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;

a sleeve positioned at least in part in the through bore of the turbocharger center housing between the compressor end and the counterbore wherein the sleeve comprises a locating flange and an axial extension that extends from the locating flange wherein the axial extension comprises 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;

a compressor side bearing that comprises an outer race, rolling elements and an inner race wherein the outer race is received at least in part by the sleeve; and

a turbine side bearing that comprises an outer race, rolling elements and an inner race wherein the outer race is received at least part between the counterbore and the turbine end and wherein the outer race is axially located at least in part by the turbine side axially facing spacer surface of the sleeve.