Turbocharger core

A turbocharger core adapted to cooperate with a cavity that provides for both receiving and discharging exhaust gases of an internal combustion engine, comprising:

• a. a turbocharger rotor assembly comprising:
• i. a turbine rotor;
• ii. a compressor rotor;
• and
• iii. a rotor shaft operatively coupling said turbine rotor to said compressor rotor, wherein said turbine rotor, said compressor rotor and said rotor shaft are operative about a common axis of rotation of said turbocharger rotor assembly;
• b. a rotor shaft support assembly comprising:
• i. a bearing housing;
• and
• ii. at least one bearing within said bearing housing, wherein said rotor shaft is rotationally supported by said at least one bearing along said rotor shaft, and said bearing housing is configured to mount to a forward end of said cavity so as to provide for closing said forward end of said cavity;
• c. a turbine nozzle cartridge assembly comprising:
• i. a forward nozzle wall, wherein said forward nozzle wall comprises a first surface, and said forward nozzle wall cooperates with a first aft portion of said bearing housing so as to provide for extending aftwardly therefrom;
• ii. an aft nozzle wall, wherein said aft nozzle wall comprises a second surface spaced apart aftwardly from said first surface;
• iii. a peripheral inlet of said turbine nozzle cartridge assembly located in a resulting gap between radially-peripheral portions of a forward portion of said forward nozzle wall and said aft nozzle wall;
• iv. a plurality of vanes between said forward and aft nozzle walls;
• v. a turbine rotor shroud portion aftwardly connected to or extending from said aft nozzle wall, wherein a region between said plurality of vanes and said forward and aft nozzle walls provides for fluid communication between said peripheral inlet and said turbine rotor shroud portion, said turbine rotor is located within said turbine nozzle cartridge assembly, said turbine nozzle cartridge assembly is located aft of said bearing housing;
• vi. a nozzle exhaust portion aftwardly connected to or extending from said turbine rotor shroud portion;
• and
• vii. an external sealing surface on an outside of an aft portion of said nozzle exhaust portion;
• and
• d. wherein said bearing housing incorporates a cylindrical step extending aftwardly from said bearing housing, said forward nozzle wall of said turbine nozzle cartridge assembly incoporates a cylindrical lip configured to cooperate with said cylindrical step, an inside diameter of said cylindrical lip and a corresponding outside diameter of said cylindrical step are configured so as to provide for an interference fit at room temperature, while also providing for thermally induced expansion of said cylindrical lip relative to said cylindrical step, further comprising a plurality of radial pins through a corresponding plurality of radial holes in said cylindrical lip of said forward nozzle wall and into said cylindrical step for retaining and substantially centering said turbine nozzle cartridge assembly concentric relative to said bearing housing and relative to said common axis of rotation of said turbocharger rotor assembly.