초록 ▼

A variable geometry turbine system for internal combustion engine turbochargers is provided which comprises a turbine wheel and a meridionally divided volute having first and second volute passageways defining first and second turbine inlet openings for the flow of exhaust gas from the passageways i

A variable geometry turbine system for internal combustion engine turbochargers is provided which comprises a turbine wheel and a meridionally divided volute having first and second volute passageways defining first and second turbine inlet openings for the flow of exhaust gas from the passageways into the turbine wheel. The system further includes closure means movable betwen a first position in which both from both volute passageways to flow into the turbine turbine inlet openings are open to permit exhaust gas wheel to provide a mixed-flow turbine during periods of high engine speed; and a second position closing the first turbine inlet opening to permit exhaust gas from only the second volute passageway to flow into the turbine wheel to provide an axial-flow turbine during periods of reduced engine speed. The closure means of the system can further include valve means for diverting during periods of reduced engine speed. The turbine all exhaust gas flow into the second volute passageway system is simple in construction, durable, low in cost and provides efficient engine operation over a full range of engine speeds.

대표청구항 ▼

A variable geometry turbine system for as internal combustion engine turbocharger comprising: a turbine wheel having a central core and a plurality of outwardly extending vanes, said turbine wheel being rotatable about a central axis; a meridionally divided volute for exhaust gas surrounding said tu

A variable geometry turbine system for as internal combustion engine turbocharger comprising: a turbine wheel having a central core and a plurality of outwardly extending vanes, said turbine wheel being rotatable about a central axis; a meridionally divided volute for exhaust gas surrounding said turbine wheel, said meridionally divided volute including means for defining first and second volute passageways having a divider wall therebetween, said first and second volute passageways defining first and second turbine inlet openings permitting exhaust gas from said first and second volute passageways, respectively, to act on the outwardly extending vanes of said turbine wheel, said first volute passageway directing exhaust gas into said turbine wheel substantially radially of said wheel and said second volute passageway directing exhaust gas into said turbine wheel substantially axially of said wheel; and closure means movable between a first position in which said first and second turbine inlet openings are open permitting exhaust gas from both said first and second volute passageways to act on the outwardly extending vanes of said turbine wheel during periods of high engine speed, and a second position in which said first turbine inlet opening is closed permitting exhaust gas from only said second volute passageway to act on the outwardly extending vanes of said turbine wheel during periods of low engine speed, said turbine comprising a mixed-flow turbine when said closure means is in said first position, and an axial flow turbine when said closure means is in said second position.