Turbine assembly for a turbocharger, having twin volutes, and associated method

摘要

A turbine assembly (10) for an exhaust gas turbocharger has separate first (24) and second (26) volutes that are sequentially activated via a valve (30) that receives exhaust gases from an engine. In a first position of the valve (30), only the first volute (24) receives exhaust gas; in a second position, both volutes (24,26) receive exhaust gases. In a third position, a bypass passage is also opened so that some exhaust gas bypasses the turbine wheel (20). Unlike conventional twin-scroll turbines, each volute receives exhaust gases from all engine cylinders, and the first volute feeds gas into the B-width portion (20a) of the wheel (20), while the second volute feeds gas into the wheel after the contour portion (20b).