A valve assembly includes a valve housing defining a flow passage configured to receive exhaust gas from an internal combustion engine, and defining a bore extending along a bore axis and fluidly coupled to said flow passage. The valve assembly also includes a valve body for controlling the flow of exhaust gas through the bore, and a shaft coupled to the valve body. The valve body is moveable between a closed position and an open position when the shaft rotates about the axis. The vale assembly additionally includes a first biasing member coupled to the shaft and configured to bias the shaft along the shaft axis in a first direction, and a second biasing member coupled to the shaft and configured to bias the valve body in the first direction along the shaft axis.

The present invention relates to an intake system for natural gas engine. An intake system for an engine is provided. A conduit is configured to direct a combustible mixture to a cylinder head. A mixing unit is coupled to the conduit. The mixing unit includes a fuel doser configured to dispense fuel into the conduit and a first mixer positioned downstream of the fuel doser. The first mixer is configured to mix air and the fuel. The mixing unit further includes a exhaust gas doser configured to dispense exhaust gas into the conduit and a second mixer positioned downstream of the exhaust gas doser. The second mixer is configured to mix the exhaust gas with the air and the fuel to make the combustible mixture. An air intake throttle is configured to direct the air into the mixing unit.

The present invention relates to an intake system for natural gas engine. An intake system for an engine is provided. A conduit is configured to direct a combustible mixture to a cylinder head. A mixing unit is coupled to the conduit. The mixing unit includes a fuel doser configured to dispense fuel into the conduit and a first mixer positioned downstream of the fuel doser. The first mixer is configured to mix air and the fuel. The mixing unit further includes a exhaust gas doser configured to dispense exhaust gas into the conduit and a second mixer positioned downstream of the exhaust gas doser. The second mixer is configured to mix the exhaust gas with the air and the fuel to make the combustible mixture. An air intake throttle is configured to direct the air into the mixing unit.

The present invention relates to an intake system for natural gas engine. An intake system for an engine is provided. A conduit is configured to direct a combustible mixture to a cylinder head. A mixing unit is coupled to the conduit. The mixing unit includes a fuel doser configured to dispense fuel into the conduit and a first mixer positioned downstream of the fuel doser. The first mixer is configured to mix air and the fuel. The mixing unit further includes a exhaust gas doser configured to dispense exhaust gas into the conduit and a second mixer positioned downstream of the exhaust gas doser. The second mixer is configured to mix the exhaust gas with the air and the fuel to make the combustible mixture. An air intake throttle is configured to direct the air into the mixing unit.

The present invention relates to an intake system for natural gas engine. An intake system for an engine is provided. A conduit is configured to direct a combustible mixture to a cylinder head. A mixing unit is coupled to the conduit. The mixing unit includes a fuel doser configured to dispense fuel into the conduit and a first mixer positioned downstream of the fuel doser. The first mixer is configured to mix air and the fuel. The mixing unit further includes a exhaust gas doser configured to dispense exhaust gas into the conduit and a second mixer positioned downstream of the exhaust gas doser. The second mixer is configured to mix the exhaust gas with the air and the fuel to make the combustible mixture. An air intake throttle is configured to direct the air into the mixing unit.

Methods and systems are provided for merging recirculated exhaust gas (EGR) with fresh intake air in an intake passage. In one example, a method may include introducing EGR to the intake passage via an angled annular slot and flowing unmixed EGR and ambient air through an intake compressor inlet. Ambient air may flow to a center of the intake compressor while the EGR may flow along a periphery of the intake compressor inlet.

Methods and systems are provided for merging recirculated exhaust gas (EGR) with fresh intake air in an intake passage. In one example, a method may include introducing EGR to the intake passage via an angled annular slot and flowing unmixed EGR and ambient air through an intake compressor inlet. Ambient air may flow to a center of the intake compressor while the EGR may flow along a periphery of the intake compressor inlet.

An intake manifold is provided. A first inlet is structured to receive pressurized intake air from a turbocharger. A second inlet is structured to receive exhaust gas recirculation gas from an exhaust gas recirculation system. A third inlet is structured to receive fuel from a fuel line. A plurality of outlets are structured to be fluidly coupled to an engine. An intake manifold passage extends between each of the first, second, and third inlets, and the plurality of outlets. The intake manifold passage is shaped so as to cause at least two reversals in flow direction of each of the intake air, the exhaust gas recirculation gas, and the fuel through the intake manifold passage so as to improve mixing of each of the intake air, the exhaust gas recirculation gas, and the fuel.

An intake manifold is provided. A first inlet is structured to receive pressurized intake air from a turbocharger. A second inlet is structured to receive exhaust gas recirculation gas from an exhaust gas recirculation system. A third inlet is structured to receive fuel from a fuel line. A plurality of outlets are structured to be fluidly coupled to an engine. An intake manifold passage extends between each of the first, second, and third inlets, and the plurality of outlets. The intake manifold passage is shaped so as to cause at least two reversals in flow direction of each of the intake air, the exhaust gas recirculation gas, and the fuel through the intake manifold passage so as to improve mixing of each of the intake air, the exhaust gas recirculation gas, and the fuel.

The subject matter of this specification can be embodied in, among other things, a gas mixer that includes a convergent-divergent nozzle comprising a convergent portion and a divergent portion and defining a first gas flow path, an air housing comprising an air inlet configured to supply air to the first gas flow path upstream of the convergent-divergent nozzle, a gas housing defining a second gas flow path and including a first gas inlet configured to receive a secondary gas and allow the secondary gas into a second gas flow path, and a gas nozzle positioned parallel to and centrally within the first gas flow path in a convergent portion of the convergent-divergent nozzle, the gas nozzle configured to supply the secondary gas to the first gas flow path upstream of the divergent portion.