Motor-assisted turbochargers for internal combustion engines

A motor-assisted turbocharger for an internal combustion engine including a charge air compressor adjacent one end of a rotatable shaft and an exhaust gas turbine adjacent the other end of the rotatable shaft, comprising:

• a compressor wheel at said one end of a rotatable shaft and a turbine wheel having central core and plurality of outwardly extending blades at said other end of the rotatable shaft;
• a bearing system for carrying said rotatable shaft,
• said bearing system comprising a first bearing providing a bearing support for said rotatable shaft at a first location on said shaft and a second bearing providing a bearing support for said rotatable shaft at a second location on said shaft axially spaced from said first location;
• a bearing system support,
• said first bearing comprising a first anti-friction roller bearing means including an inner race engaging said shaft, an outer race, and a plurality of roller bearings interposed between said inner race and said outer race, said outer race extending axially from said first location to said second location of said rotatable shaft and providing said second bearing, said outer race having an outer bearing surface and radially extending thrust bearing surfaces adapted to be rotatably carried by said bearing system support, said bearing system being free to rotate within the bearing system support;
• an assisting electric motor adjacent said compressor wheel and a compressor casing at the compressor end of said turbocharger for receiving compressed air for the compressor wheel;
• and
• a meridionally divided volute for exhaust gas surrounding the turbine wheel and defining a turbine wheel opening permitting exhaust gas from said volute to act on the outwardly extending blades of the turbine wheel.

A motor-assisted turbocharger for an internal combustion engine including a charge air compressor adjacent one end and an exhaust gas turbine adjacent the other end, comprising:

• a compressor wheel at a compressor end of a rotatable shaft, and a turbine wheel having central core and plurality of outwardly extending blades at a turbine end of the rotatable shaft;
• a bearing system for said rotating shaft, including:
• an independent outer race adapted to be rotatable in a support and carried on a film of lubricant and to provide a thrust bearing and a rolling bearing at the compressor end of the outer race and a sleeve bearing at the turbine end of the outer race, said independent outer race having an elongated cylindrical bearing surface and radially extending thrust bearing surfaces, and
• a housing rotatably supporting said independent outer race;
• an assisting electric motor adjacent said compressor wheel and a compressor casing at the compressor end of said turbocharger for receiving compressed air for the compressor wheel;
• and
• a meridionally divided volute for exhaust gas surrounding the turbine wheel and defining a turbine wheel opening permitting exhaust gas from said volute to act on the outwardly extending blades of the turbine wheel.