Turbocharger for an internal combustion engine

A turbocharger for an engine, comprising:

• a housing;
• a shaft having a first end and a second end opposite the first end;
• a turbine wheel mounted to the first end of the shaft for rotation therewith;
• a compressor wheel mounted to the second end of the shaft for rotation therewith, the housing being positioned axially between the turbine wheel and the compressor wheel;
• a compressor backplate disposed axially between the housing and the compressor wheel, the compressor backplate defining a plurality of radially-extending passages and an annular passage connected to the radially-extending passages;
• and
• a bearing cartridge rotatably supporting the shaft relative to the housing, the bearing cartridge comprising:
• an inner ring mounted to the shaft;
• an outer ring disposed between the inner ring and the housing, the outer ring being movable relative to the housing, the outer ring having a first end facing toward the turbine wheel and a second end facing toward the compressor wheel;
• a first plurality of rolling elements disposed radially between the inner and outer rings and rotatably supporting the inner ring relative to the outer ring;
• and
• a second plurality of rolling elements disposed radially between the inner and outer rings and rotatably supporting the inner ring relative to the outer ring, the second plurality of rolling elements being axially spaced apart from the first plurality of rolling elements;
• a radial gap being defined between the outer ring and the housing, lubricant flowing into the radial gap and radially separating the outer ring from the housing during operation of the turbocharger, the lubricant flowing from the radial gap into the radially-extending passages and into the annular passage;
• a first axial gap being defined between the first end of the outer ring and the housing, the lubricant flowing into the first axial gap and axially separating the first end of the outer ring from the housing during operation of the turbocharger;
• a second axial gap being defined between the second end of the outer ring and the compressor backplate, the lubricant flowing into the second axial gap and axially separating the second end of the outer ring from the compressor backplate.