AUTOMOTIVE TURBOCHARGER SYSTEMS

摘要

A turbocharger system for an automotive engine comprising an air inlet duct (10), an exhaust gas duct (18) and first and second turbochargers. The first turbo charger is substantially smaller than the second turbocharger. Each turbocharger includes an exhaust turbine (20, 24) situated in the exhaust duct (18) and a blower wheel (22, 26) situated in the inlet duct (10). A bypass duct (28) is connected to the exhaust duct upstream and downstream of the exhaust turbine (20) of the first turbocharger. The bypass duct (28) includes a valve flap (44) pivotally mounted within a housing (30). The internal wall of the housing (30) carries two oppositely directed semi-annular sealing surfaces (46) extending transversely to the direction of the exhaust gas flow. The valve flap (44) is moveable by an actuator (32) between an open position in which the bypass duct is substantially unrestricted and a closed position in which it is in sealing engagement with the two sealing surfaces (46).