Abstract: An exhaust gas treatment system of an internal combustion engine includes a selective catalytic reduction catalyst fluidly connected to the internal combustion engine, a particulate filter fluidly connected downstream of the selective catalytic reduction catalyst, and an induction line configured to direct a portion of a filtered exhaust flow of the internal combustion engine toward an inlet of the engine.

Abstract: A method of ammonia production for a selective catalytic reduction system is provided. The method includes producing an exhaust gas stream within a cylinder group, wherein the first exhaust gas stream includes NOx. The exhaust gas stream may be supplied to an exhaust passage and cooled to a predetermined temperature range, and at least a portion of the NOx within the exhaust gas stream my be converted into ammonia.

Abstract: A system of ammonia production for a selective catalytic reduction system is provided. The system includes producing an exhaust gas stream within a cylinder group, wherein the first exhaust gas stream includes NOx. The exhaust gas stream may be supplied to an exhaust passage and cooled to a predetermined temperature range, and at least a portion of the NOx within the exhaust gas stream may be converted into ammonia.

Abstract: An exhaust system for a combustion engine is disclosed. The exhaust system may have a housing connected to receive a flow of exhaust. The exhaust system may also have a first catalyst disposed within the housing to reduce the concentration of an exhaust constituent, and a second catalyst disposed within the housing downstream of the first catalyst to further reduce the concentration of the exhaust constituent. The exhaust system may further have a sensor disposed between the first and second catalysts to generate a signal indicative of the concentration of the exhaust constituent at the location between the first and second catalysts. The exhaust system may additionally have a controller in communication with the sensor to receive the signal. The controller may determine, based on the received signal, the concentration of the exhaust constituent at a location downstream of the second catalyst.

Abstract: An engine, an exhaust system, and a method for reducing NOx in an exhaust stream are provided. The system comprises a first SCR catalyst, a second SCR catalyst, and a particulate filter positioned between the first and second SCR catalyst. The engine comprises an intake air system, at least one combustion chamber, and an exhaust system comprising a first SCR catalyst positioned upstream of a particulate filter and a second SCR catalyst positioned downstream of the particulate filter. The method comprises the steps of passing the exhaust through a low-temperature SCR catalyst, passing the exhaust through a particulate filter, and passing the exhaust through a high-temperature SCR catalyst.

Abstract: An engine is provided. The engine may comprise a first cylinder group including at least one cylinder configured to operate in a two-stroke engine operating mode and a second cylinder group including at least two cylinders configured to operate in a four-stroke engine operating mode. The power outputs of each of the cylinders in the first cylinder group and second cylinder group may be approximately equal.

Abstract: A power source is provided for use with an exhaust gas recirculation and selective catalytic reduction system. The power source has a main air-intake passage fluidly connected to a first air-intake passage and a second air-intake passage. A first cylinder group may be fluidly connected to the first air-intake passage and a first exhaust passage, wherein the first exhaust passage may include an ammonia-producing catalyst configured to convert at least a portion of a fluid in the first exhaust passage into ammonia. Further, a second cylinder group may be fluidly connected to the second air-intake passage and a second exhaust passage. A third cylinder group may be fluidly connected to the second air-intake passage. The power source may have a recirculation loop that includes the second air-intake passage and the third cylinder group.

Abstract: An engine valve actuation system is provided. The engine valve actuation system includes an intake valve that is moveable between a first position to prevent a flow of fluid and a second position to allow a flow of fluid. A cam assembly is configured to move the intake valve between the first position and the second position. A fluid actuator is configured to selectively prevent the intake valve from moving to the first position. A source of fluid is in fluid communication with the fluid actuator. A directional control valve is configured to control a flow of fluid between the source of fluid and the fluid actuator. A check valve is disposed between the directional control valve and the source of fluid, only allowing fluid flow from the fluid source to the directional control valve. A bleed orifice may be disposed between the directional control valve and the source of fluid, in parallel with the check valve.

Abstract: An engine valve actuation system is provided. The engine valve actuation system includes an intake valve that is moveable between a first position to prevent a flow of fluid and a second position to allow a flow of fluid. A cam assembly is configured to move the intake valve between the first position and the second position. A fluid actuator is configured to selectively prevent the intake valve from moving to the first position. A source of fluid is in fluid communication with the fluid actuator. A directional control valve is configured to control a flow of fluid between the source of fluid and the fluid actuator. A check valve is disposed between the directional control valve and the source of fluid, only allowing fluid flow from the fluid source to the directional control valve. A bleed orifice may be disposed between the directional control valve and the source of fluid, in parallel with the check valve.

Abstract: A spool slides in a bore to open and close a valve. The spool moves in a first direction until the spool forcibly engages a seat in the bore, closing the valve. The spool moves in a second direction opposite the first direction so that the spool disengages with the seat, opening the valve. Proper configuration of the spool and bore geometries in the vicinity of the seat keeps static pressure from developing that could otherwise retard spool valve opening.

Abstract: A spool slides in a bore to open and close a valve. An armature moveable relative to the spool is biased in a first direction. A coupling biasing member biases the armature and the spool toward each other. When a solenoid is actuated the armature and the spool move in a second direction opposite the first direction until the spool forcibly engages a seat in the bore, closing the valve and stopping the spool movement. The armature continues to move in the second direction, causing the coupling to apply additional force to keep the spool engaged against the seat, until the armature reaches a second position where it forcibly engages with the spool. This stops the armature from moving further in the second direction, but allows the stationary armature to continue applying force to keep the spool engaged against the seat. When the solenoid is de-energized the armature bias sends the armature back in the first direction until it strikes the spool, causing the spool to rapidly unseat, thus opening the valve.