Axial Turbine With Sector-Divided Turbine Housing

摘要

A statorless or nozzleless axial turbine for a turbocharger has an axial turbine wheel that receives a swirling flow of exhaust gas substantially in an axial direction. The turbine includes a sector-divided turbine housing defining a plurality of separate exhaust gas inlets each for receiving a separate exhaust gas stream from an internal combustion engine, the sector-divided turbine housing further defining a plurality of separate angular sector passageways each of which occupies a fractional part of a circumference surrounding the turbine wheel, each angular sector passageway being supplied with exhaust gas by a respective one of the plurality of exhaust gas inlets. The turbine housing assembly defines a separate sector outlet for each angular sector passageway. The turbine housing assembly can include a separately formed heat shroud, and the sector outlets can be formed at least in part by the heat shroud.

主权项

1. An axial turbine for an exhaust-gas-driven turbocharger, the turbine having no inlet stator, and comprising:
an axial turbine wheel comprising a hub and a plurality of blades extending generally radially outward from the hub, and a turbine housing assembly that houses the turbine wheel; the turbine housing assembly comprising a sector-divided turbine housing, the sector-divided turbine housing defining a plurality of separate exhaust gas inlets into the turbine housing, each exhaust gas inlet for receiving a separate exhaust gas stream from an internal combustion engine, the sector-divided turbine housing further defining a plurality of separate angular sector passageways each of which occupies a fractional part of a circumference surrounding the turbine wheel, the angular sector passageways succeeding one another in a circumferential direction, each angular sector passageway being supplied with exhaust gas by a respective one of the plurality of exhaust gas inlets, each angular sector passageway being characterized by a convergent cross-section that spirals inward and converges to accelerate the exhaust gas; the turbine housing assembly defining a separate sector outlet for each angular sector passageway through which the respective exhaust gas stream is fed into an inlet side of the turbine wheel generally in an axial direction of the turbine wheel.