Patent ID: 6920754

Claim:
A turbocharger comprising: a center housing having a shaft disposed rotatably therein, the shaft having a first end and a second end; a turbine housing connected to one end of the center housing and having a turbine wheel rotatably disposed therein, the turbine wheel being attached to the shaft first end; the compressor backplate attached to an end of the center housing opposite the turbine housing; a compressor housing connected to the compressor backplate, the compressor housing comprising: a first-stage section comprising a compressor housing air inlet and including a first-stage compressor impeller rotatably disposed therein, the first-stage compressor impeller being attached to the shaft second end and being positioned in air-flow communication with the air inlet, the first-stage section including an air outlet passage positioned downstream of the first-stage compressor impeller; a second-stage section connected between the first-stage section and the backplate, the second-stage section including a second-stage compressor impeller rotatably disposed therein and attached to the shaft adjacent the first-stage compressor impeller, the second-stage section including an interstage flow passage positioned downstream from the air outlet passage and upstream from the second-stage compressor impeller, the interstage flow passage being at least partially defined by the backplate; and a scroll seal positioned within the compressor housing between the first-stage and second-stage compressor impellers.