pneumatically driven vacuum pump, exhaust driven turbocharging system and system including a normally aspirated engine

摘要

A pneumatically driven vacuum pump is described, including a body defining a converging driving section, a diverging discharge section, at least one suction port, and a venturi opening. The venturi opening is located between an outlet end of the converging drive section and an inlet end of the diverging discharge section. The pneumatically driven vacuum pump also includes a first check valve connected to the venturi opening and suction port. The pneumatically driven vacuum pump further includes at least a second opening located in the diverging discharge section of the body, downstream of the venturi opening. A second check valve is connected to the second port.