Abstract: An aftertreatment system comprises a reductant storage tank and a SCR system including a catalyst for reducing constituents of an exhaust gas. A reductant insertion assembly is fluidly coupled to the reductant storage tank and the SCR system. A controller is communicatively coupled to the reductant insertion assembly. The controller is configured to: determine an initial pressure of the reductant, determine a first pressure at which the reductant is to be delivered to the selective catalytic reduction system and adjust an operating parameter of the reductant insertion assembly. The adjustment of the operating parameter results in an at least selective delivery of the reductant at the first pressure to the SCR system.

Abstract: An aftertreatment system comprises a reductant storage tank and a SCR system including a catalyst for reducing constituents of an exhaust gas. A reductant insertion assembly is fluidly coupled to the reductant storage tank and the SCR system. A controller is communicatively coupled to the reductant insertion assembly. The controller is configured to: determine an initial pressure of the reductant, determine a first pressure at which the reductant is to be delivered to the selective catalytic reduction system and adjust an operating parameter of the reductant insertion assembly. The adjustment of the operating parameter results in an at least selective delivery of the reductant at the first pressure to the SCR system.

Abstract: An aftertreatment system comprises a reductant storage tank and a SCR system including a catalyst for reducing constituents of an exhaust gas. A reductant insertion assembly is fluidly coupled to the reductant storage tank and the SCR system. A controller is communicatively coupled to the reductant insertion assembly. The controller is configured to: determine an initial pressure of the reductant, determine a first pressure at which the reductant is to be delivered to the selective catalytic reduction system and adjust an operating parameter of the reductant insertion assembly. The adjustment of the operating parameter results in an at least selective delivery of the reductant at the first pressure to the SCR system.

Abstract: An aftertreatment system comprises a reductant storage tank and a SCR system including a catalyst for reducing constituents of an exhaust gas. A reductant insertion assembly is fluidly coupled to the reductant storage tank and the SCR system. A controller is communicatively coupled to the reductant insertion assembly. The controller is configured to: determine an initial pressure of the reductant, determine a first pressure at which the reductant is to be delivered to the selective catalytic reduction system and adjust an operating parameter of the reductant insertion assembly. The adjustment of the operating parameter results in an at least selective delivery of the reductant at the first pressure to the SCR system.

Abstract: A fuel pump assembly for an internal combustion engine includes a fuel pump housing, a cylindrical bore defined in the fuel pump housing, and a tappet assembly received in the cylindrical bore. The tappet assembly includes a one-piece shoe having a recess disposed in a bottom portion thereof, and a roller that is partially received within the recess and configured to rotate about a roller axis.

Abstract: A system including a reductant source storing reductant, an ammonia generation system configured to generate gaseous ammonia via cavitation, and a gaseous ammonia delivery device in fluid communication with the ammonia generation system and an exhaust system. The system may selectively activate the ammonia generation system responsive to a detected temperature of an exhaust gas of an exhaust system being equal to or below a predetermined value. The ammonia generation system may utilize ultrasonic cavitation or laser cavitation to generate gaseous ammonia to be delivered to the exhaust system responsive to the temperature of the exhaust gas of the exhaust system being equal to or below the predetermined value. If the temperature of the exhaust gas of the exhaust system above the predetermined value, a dosing module to dose reductant to the exhaust system may be activated.

Abstract: A fuel pump is disclosed wherein a substantially cylindrical plunger bore is provided with an annular drain groove fluidically coupled to a drain duct. A pump plunger is driven by a drive system located in a separate mechanical compartment that holds a reservoir of lubricating oil. An annular seal is provided adjacent the drain groove substantially at the end of the bore and retained in position by a seal support. Exemplary embodiments provide the drain groove and seal as being positioned immediately adjacent one another so that the seal forms a lower wall of the drain groove.

Abstract: A system including a reductant source storing reductant, an ammonia generation system configured to generate gaseous ammonia via cavitation, and a gaseous ammonia delivery device in fluid communication with the ammonia generation system and an exhaust system. The system may selectively activate the ammonia generation system responsive to a detected temperature of an exhaust gas of an exhaust system being equal to or below a predetermined value. The ammonia generation system may utilize ultrasonic cavitation or laser cavitation to generate gaseous ammonia to be delivered to the exhaust system responsive to the temperature of the exhaust gas of the exhaust system being equal to or below the predetermined value. If the temperature of the exhaust gas of the exhaust system above the predetermined value, a dosing module to dose reductant to the exhaust system may be activated.

Abstract: A fuel pump is disclosed wherein a substantially cylindrical plunger bore is provided with an annular drain groove fluidically coupled to a drain duct. A pump plunger is driven by a drive system located in a separate mechanical compartment that holds a reservoir of lubricating oil. An annular seal is provided adjacent the drain groove substantially at the end of the bore and retained in position by a seal support. Exemplary embodiments provide the drain groove and seal as being positioned immediately adjacent one another so that the seal forms a lower wall of the drain groove.

Abstract: A fuel pump assembly for an internal combustion engine includes a fuel pump housing, a cylindrical bore defined in the fuel pump housing, and a tappet assembly received in the cylindrical bore. The tappet assembly includes a one-piece shoe having a recess disposed in a bottom portion thereof, and a roller that is partially received within the recess and configured to rotate about a roller axis.

Abstract: A fuel pump is disclosed wherein a substantially cylindrical plunger bore is provided with an annular drain groove fluidically coupled to a drain duct. A pump plunger is driven by a drive system located in a separate mechanical compartment that holds a reservoir of lubricating oil. An annular seal is provided adjacent the drain groove substantially at the end of the bore and retained in position by a seal support. Exemplary embodiments provide the drain groove and seal as being positioned immediately adjacent one another so that the seal forms a lower wall of the drain groove.

Abstract: A piezoelectric fuel injection system and a method of controlling same are provided which include a piezoelectric fuel injector having a piezoelectric element, a power source adapted to provide power to the piezoelectric element to actuate the piezoelectric fuel injector, and a controller adapted to charge the piezoelectric element to an initial voltage to begin said injection event, to decrease the voltage from the initial voltage to an intermediate voltage, and to increase the voltage from the intermediate voltage to a primary voltage to thereby control the injection rate shape. The initial voltage level is at least approximately equal to said primary voltage level and preferably approximately equal to a maximum voltage rating. The initial voltage duration, the intermediate voltage duration and the magnitude of the intermediate voltage can be changed or varied to modify the injection or rate shape.

Abstract: A method for adjusting piezoelectric valve components to create a precise interface between a piezoelectric actuator and a movable valve plunger is provided which includes the steps of conducting a coarse adjustment prior to assembly followed by a fine adjustment after assembly. The method includes measuring a first difference between a valve body and a valve plunger, and compensating for this first measured difference such that surfaces of the valve body and the valve plunger are in a common plane. A second common plane is established between an end surface of an actuator housing and an end of an actuator rod. The step of compensating for the first measured difference can comprise machining the surfaces in the first common plane or using a shim. A second adjustment is conducted by rotating a nut disposed axially with the actuator rod to adjust the axial position of the valve plunger.

Abstract: A piezoelectric fuel injection system and a method of controlling same, the system including a piezoelectric fuel injector having a piezoelectric element, a power source adapted to provide power to the piezoelectric element to actuate the piezoelectric fuel injector, and a controller adapted to cyclically modulate power provide to the piezoelectric element by the power source during at least a portion of the injection event. The controller cyclically modulates the power between a predetermined first voltage and a predetermined second voltage that is less than the first voltage to control the rate of fuel injected by the piezoelectric fuel injector during the portion of the injection.

Abstract: An injector is provided which includes a nozzle valve element, a control volume, and an injection control valve including a control valve member for controlling fuel flow from the control volume so as to control nozzle valve movement. Importantly, the injector includes a nozzle valve lift detecting device for detecting nozzle valve lift and providing a nozzle valve element lift feedback signal. Feedback signals are improved and control valve member oscillations are minimized by positioning a valve seat associated with the control valve member a spaced distance from the control volume, positioning a drain orifice such that the nozzle valve element restricts flow through a drain circuit when in an open position and extending the control valve member from the valve seat to the control volume to form an end wall of the control volume.

Abstract: The fuel injector includes a solid state actuator that operates through an actuator motion amplifying lever to directly control the needle valve motion. Hydraulic forces, which act along the axes of the needle valve and the motion amplifying lever, are compensated by using a control piston, or other biasing means, to reduce the required amplitude of the control current/voltage and to reduce the required strength of the spring biasing the needle valve closed. The fuel injector may also include a control fuel inlet that is separate from the injection fuel inlet port.

Abstract: An injector is provided which includes a nozzle valve element, a control volume, and an injection control valve including a control valve member for controlling fuel flow from the control volume so as to control nozzle valve movement. Importantly, the injector includes a nozzle valve lift detecting device for detecting nozzle valve lift and providing a nozzle valve element lift feedback signal. Feedback signals are improved and control valve member oscillations are minimized by positioning a valve seat associated with the control valve member a spaced distance from the control volume, positioning a drain orifice such that the nozzle valve element restricts flow through a drain circuit when in an open position and extending the control valve member from the valve seat to the control volume to form an end wall of the control volume.

Abstract: The fuel injector includes a solid state actuator that operates through an actuator motion amplifying lever to directly control the needle valve motion. Hydraulic forces, which act along the axes of the needle valve and the motion amplifying lever, are compensated by using a control piston, or other biasing means, to reduce the required amplitude of the control current/voltage and to reduce the required strength of the spring biasing the needle valve closed. The fuel injector may also include a control fuel inlet that is separate from the injection fuel inlet port.

Abstract: A piezoelectric actuator assembly that is insensitive to wide variations in operating temperatures including a stack of piezoelectric devices and a surrounding housing assembly formed of an outer cylindrical housing portion formed of steel having a coefficient of thermal expansion above that of the piezoelectric material and an inner cylindrical housing portion formed of Si—Ni ceramic. By arranging the inner and outer housing portions in parallel and forming the housing portions with appropriate cross-sectional areas, the housing assembly will have an effective coefficient of thermal expansion &agr;e that is equivalent to that of the piezoelectric element &agr;p.

Abstract: A fuel injector including a floating sleeve control chamber is provided which effectively minimizes friction and wear, and thus prevents stiction, of a nozzle valve element by avoiding the need to align two bore guiding surfaces for the element. The floating sleeve control chamber includes a floating sleeve positioned on a control piston formed integrally with a nozzle valve element and positioned in a cavity. The floating sleeve is sized with an outer extent or diameter sufficiently less than the size of a surrounding cavity wall so as to permit lateral movement of the floating sleeve and thus movement of the control chamber. Only the nozzle valve element guiding bore surfaces control the alignment of the nozzle valve element relative to its seat while the floating sleeve effectively forms and seals a floating control chamber. The floating sleeve may be formed from one or more sleeve sections.