Multi-stage turbocharger system with off-engine low pressure stage

A method for assembly of a combustion engine, including:

• providing the combustion engine;
• mounting at least one high pressure turbocharger system on-engine to a block of the combustion engine, wherein the at least one high pressure turbocharger system includes at least one high pressure turbine and at least one high pressure compressor operably connected to the at least one high pressure turbine;
• fluidly connecting the at least one high pressure turbine to at least one exhaust manifold of the combustion engine;
• fluidly connecting the at least one high pressure compressor to at least one intake manifold of the combustion engine;
• mounting at least one low pressure turbocharger system off-engine to a support structure, the at least one low pressure turbocharger system including at least two low pressure turbines and at least two low pressure compressors operably connected to respective ones of the at least two low pressure turbines, wherein the at least one low pressure turbocharger system is mounted to the support structure so that a substantial portion of a static load of the at least one low pressure turbocharger system is not transferred to the engine block;
• fluidly connecting one of the at least two low pressure compressors to the at least one of the high pressure compressor;
• fluidly connecting one of the at least two low pressure turbines to the at least one of the high pressure turbine;
• mounting at least one aftercooler on-engine in fluid communication with and between the at least one of the intake manifold and the at least one of high pressure compressor;
• and
• mounting at least one intercooler off-engine to the support structure in fluid communication with and between the at least two low pressure compressors and the high pressure compressor, wherein outlets of each of the first and second low pressure compressors are connected to the at least one intercooler by respective ones of first and second intake passage portions that extend to the at least one intercooler.

An internal combustion engine system comprising:

• an internal combustion engine including an engine block, at least one intake passage for receiving and delivering an air flow to at least a portion of a plurality of cylinders of the engine block and at least one exhaust passage for receiving exhaust gas from the at least the portion of the plurality of cylinders;
• at least one high pressure turbocharger including at least one high pressure turbine situated in the at least one exhaust passage from the internal combustion engine, the at least one high pressure turbocharger further including at least one first high pressure compressor operably connected with the at least one first high pressure turbine with the at least one high pressure compressor situated in the at least one intake passage, wherein the at least one high pressure turbocharger is mounted on-engine to the engine block;
• first and second support structures;
• and
• first, second, third and fourth low pressure turbochargers having an associated first, second, third and fourth low pressure turbines situated in the at least one exhaust passage downstream of the at least one high pressure turbine, the four low pressure turbochargers including first, second, third, and fourth low pressure compressors, operably connected to respective ones of the first, second, third and fourth low pressure turbines to provide compressed intake air flow to the at least one high pressure turbocharger through the at least one intake passage,
• wherein the first and second low pressure turbochargers are mounted off-engine to the first support structure on a first side of the internal combustion engine and respective outlets of the first and second low pressure compressors are connected by respective ones of first and second intake passage portions to a first intercooler that is supported on the first support structure, and the third and fourth low pressure turbochargers are mounted off-engine to the second support structure on a second side of the internal combustion engine opposite the first side so that a substantial portion of a static loads associated with the first, second, third and fourth low pressure turbochargers are not transferred to the engine block and respective outlets of the third and fourth low pressure compressors are connected by respective ones of third and fourth intake passage portions to a second intercooler that is supported on the second support structure.