Patent ID: 8454242

Claim:
An assembly for a turbocharger, the assembly comprising: a ball bearing cartridge that comprises two sets of rolling elements and an outer race wherein the outer race comprises a center section surface having a center section diameter, two intermediate section surfaces having an intermediate section diameter and two outer section surfaces having an outer section diameter, the sections disposed along an axial length defined by two opposing ends of the outer race, step transitions, each of the step transitions positioned between a respective one of the outer section surfaces and a respective one of the intermediate section surfaces, and two wells, each of the wells positioned between the center section surface and a respective one of the intermediate section surfaces, wherein each of the wells comprises a lubricant channel to direct lubricant to a respective set of the two sets of rolling elements; a center housing that comprises a lubricant inlet, an inner wall that defines a bore wherein the inner wall comprises a lubricant opening to receive lubricant from the lubricant inlet, a first inner surface having a first inner diameter, and a second inner surface having a second inner diameter wherein the first inner diameter exceeds the second inner diameter, a turbine end counterbore having a counterbore inner diameter wherein the section diameters of the outer race exceed the counterbore inner diameter, and a compressor end surface that comprises a recess; and a compressor backplate that comprises an axial extension configured to fit into the recess wherein the axial extension comprises an opening having an inner diameter less than the section diameters of the outer race; wherein the counterbore and the backplate define an axial length of a bearing cartridge chamber wherein the axial length of the chamber exceeds the axial length of the outer race to provide clearance between the outer race and the chamber.