Abstract: A dual fuel engine powers a machine by burning natural gas and liquid diesel fuel. When operating in a low load mode, some of the engine cylinders are fueled with a high ratio of diesel/gas, and the remaining cylinders are unfueled. When operating in a high load mode, all of the engine cylinders are fueled with a low ratio of diesel/gas. When operating in a limp home mode, the fuel injectors are configured to inject only diesel fuel into all of the plurality of engine cylinders.

Abstract: A fuel injector includes first and second check valve members that open and close first and second nozzle outlet sets, respectively, to inject two fuels that differ in at least one of chemical identity, pressure and molecular state. The first check valve member defines a through passage, includes a closing hydraulic surface exposed to fluid pressure in the first control chamber, and moves into and out of contact with a first seat on an injector body. The second check valve member includes a closing hydraulic surface exposed to fluid pressure in a second control chamber, and moves into and out of contact with a second seat located on the first check valve member. A control valve member is movable between first and second positions that respectively block and allow fluid communication between the first and second control chambers and a drain outlet.

Abstract: A machine includes a machine body and a dual fuel compression ignition engine attached to the machine body. A dual fuel system is operably coupled to supply the engine with liquid diesel fuel and natural gas fuel directly into respective cylinders of the engine. The fuel system includes an insulated tank for storing the natural gas fuel, a pressure sensor positioned to measure fluid pressure within the tank, and a pump for drawing the natural gas fuel from the tank. An electronic controller is in communication with the pressure sensor and has a cryogenic system diagnostics algorithm executable thereon that is configured to receive a pressure signal from the pressure sensor, detect a cryogenic system fault based on the signal, and generate a notification signal based on the fault.

Abstract: A fuel injector includes a first check valve member that seats on an injector body, and a second check valve member that seats on the first check valve member covers a first nozzle outlet set when in a closed position. When the first check valve member moves to an open position, gaseous fuel is injected through both a first nozzle outlet set and a second nozzle outlet set. When the second check valve member moves to an open position, liquid fuel moves through a through passage defined by the first check valve member to facilitate injection of the second nozzle outlet set. The first and second check valve members may be controlled by first and second control valves, respectively.

Abstract: A dual fuel common rail engine supplies pressurized natural gas and liquid diesel fuel at different pressures through a co-axial quill assembly for direct injection from a single fuel injector into an engine cylinder. Each coaxial quill assembly includes a matched pair of inner and outer quills that are chosen to have dimensions that allow both quills to sealingly engage each fuel injector at a common conical seat responsive to a clamping force applied along an axis. Matched pairs of inner and outer quills are retained together during pre-installation handling with a retainer that is left between the inner and outer quills after installation in an engine.

Abstract: An engine system is disclosed that combusts both gaseous and diesel fuels. The system includes a diesel reservoir in communication with an internal combustion engine via a diesel rail. The system also includes a liquefied gaseous fuel reservoir in communication with the internal combustion engine via a gaseous fuel rail. The gaseous fuel and diesel rails both are in communication with a pressure control device. The pressure control device measures the pressure differential between the gaseous fuel and diesel rails. If the pressure differential exceeds a desired range, the pressure control device vents gaseous fuel from the gaseous fuel rail to a spark ignited engine, where the vent gas is used as fuel. The spark ignited engine then converts the vented gaseous fuel to useful work.

Abstract: A dual fuel injector in a dual common rail fuel system includes an injector body defining a liquid fuel supply passage to a liquid fuel nozzle outlet, and a gaseous fuel supply passage to a gaseous fuel nozzle outlet. A liquid fuel needle check is movable within the injector body and has an opening hydraulic surface exposed to a fuel pressure of a liquid fuel common rail. A gaseous fuel needle check is positioned side by side with the liquid fuel needle check and has an opening hydraulic surface exposed to the fuel pressure of the liquid fuel common rail. Sensitivity to differences in gaseous fuel rail pressure and liquid fuel rail pressure is reduced by the design.

Abstract: A seal arrangement for a needle valve in a fuel injector (100) includes a nozzle housing (122) forming an outer cavity (216) and defining a needle valve seat (218). A plurality of nozzle openings (204) are formed in the nozzle housing (122) and arranged symmetrically around its centerline at a first radial distance (R1). An outer needle valve (104) is reciprocally mounted in the outer cavity (216) and has a seat portion (224) arranged to abut the needle valve seat (218) when the outer needle valve (104) is seated or closed. A first ledge (502) formed on the seat portion (224) of the outer needle valve (104) sealably contacts the needle valve seat (218) along a first line contact seal (220) and a second ledge (508) formed on the seat portion (224) of the outer needle valve (104) sealably contacts the needle valve seat (218) along a second line contact seal (222).

Abstract: Various fuel injection systems and fuel injectors are disclosed that provide varying cooling rates for fuel injectors connected in series to fuel supply and drain rail. The local cooling rate for each injector is manipulated to balance the heat flux or heat transfer across the injectors disposed along the rail. The cooling rates may be manipulated by varying sizes of openings or slots in the nozzle case, by varying annular spaces disposed between the nozzle case and the portion of the injector body that houses the actuator and solenoid assembly, and by varying the size of annular spaces disposed between the nozzle case and the cylinder head. Strategic placement of slots in the nozzle case that direct more flow at the portion of the injector body that houses the actuator and solenoid assembly may also be employed. As a result, the operating temperatures of fuel injectors connected in series to a fuel rail can be manipulated and moderated so the downstream injectors are not prone to overheating.

Abstract: Fuel injectors are disclosed that are capable of simultaneously delivering liquid and gaseous fuels to the combustion chamber of a compression ignition engine. For example, fuel injectors are disclosed that can deliver liquid diesel fuel, as a pilot liquid, along with a gaseous fuel, such as natural gas or other available fuels that are gases at atmospheric pressure and ambient temperature. The fuels are delivered to the needle control valve cavity sequentially via separate passageways. The delivery of the pressurized liquid fuel is actuated by the single actuator that is provided for each fuel injector. The actuator may be of a solenoid type or of a piezoelectric type or other suitable actuator as will be apparent to those skilled in the art. A liquid fuel check valve, in combination with the actuator, controls the delivery of the pilot liquid fuel to the needle control valve cavity.

Abstract: A mechanically actuated electronically controlled unit injector includes an electronically controlled spill valve to precisely control timing of fuel pressurization within a fuel pressurization chamber. Cavitation bubbles may be generated in the region of the valve seat when the spill valve member is closed to raise fuel pressure in the fuel injector. This cavitation can cause erosion on the spill valve member and the surrounding injector body. In order to preempt cavitation damage, the valve member may be modified to include a compound annulus that includes a small annulus that corresponds to an identified cavitation damage pattern. Although the generation of cavitation bubbles may continue after such a strategy, cavitation erosion, and the associated liberation of metallic particles into the fuel system can be reduced, and maybe eliminated, by the preemptive cavitation reduction strategy.

Abstract: An electrically controlled fuel injector includes an armature that is movable between a first armature position and a second armature position inside an armature cavity containing fuel. By reducing the size of the armature cavity to a squish film drag gap, the armature experiences a squish film drag phenomenon when the armature moves from the first armature position to the second armature position reducing the armature travel speed but also reducing the settling time of the armature after an injection event. By reducing the armature travel speed, the armature experiences a reduction in magnitude of armature bounce allowing the armature to settle down quicker and produce minimum controllable injection events with shorter dwell times than predecessor fuel injectors, especially for close coupled post injection events.

Abstract: A fuel system includes a plurality of fuel injectors each defining a nozzle supply passage, a nozzle outlet, a low pressure space, and a drain. The fuel system includes a plurality of mechanically actuated pressure intensifiers each including a tappet and being positioned partially within one of the fuel injectors, and a common rail fluidly connecting with each of the fuel injectors. Each of the fuel injectors further includes an injection pressure control mechanism having an injection pressure control valve. Each injection pressure control valve blocks the corresponding pressure intensifier from the common rail and fluidly connects the pressure intensifier with the low pressure space at a first position, and fluidly connects the pressure intensifier with the common rail and blocks the pressure intensifier from the low pressure space at a second position. Each of the fuel injectors further includes a pressure recovery mechanism having a pressure recovery valve.

Abstract: Various fuel injection systems and fuel injectors are disclosed that provide varying cooling rates for fuel injectors connected in series to fuel supply and drain rail. The local cooling rate for each injector is manipulated to balance the heat flux or heat transfer across the injectors disposed along the rail. The cooling rates may be manipulated by varying sizes of openings or slots in the nozzle case, by varying annular spaces disposed between the nozzle case and the portion of the injector body that houses the actuator and solenoid assembly, and by varying the size of annular spaces disposed between the nozzle case and the cylinder head. Strategic placement of slots in the nozzle case that direct more flow at the portion of the injector body that houses the actuator and solenoid assembly may also be employed. As a result, the operating temperatures of fuel injectors connected in series to a fuel rail can be manipulated and moderated so the downstream injectors are not prone to overheating.

Abstract: A relatively inexpensive robust attachment strategy that insures good perpendicularity between a valve member and an armature utilizes an intervening nut between the armature and valve member. A valve member is received in a guide bore of a valve body. A nut is threaded onto one end of a valve member. The armature is press fit onto a orientation neutral interface of the nut, and a fixture is utilized to set near perfect perpendicularity between an air gap plane of the armature and a centerline of the valve member. The armature is then welded to the valve member. The weld may be accomplished via laser welding while the valve assembly is firmly held in an appropriate position within the fixture. The valve assembly may be then incorporated into a fuel injector stack of components in a conventional manner.

Abstract: An electrically controlled fuel injector includes an armature that is movable between a first armature position and a second armature position inside an armature cavity containing fuel. By reducing the size of the armature cavity to a squish film drag gap, the armature experiences a squish film drag phenomenon when the armature moves from the first armature position to the second armature position reducing the armature travel speed but also reducing the settling time of the armature after an injection event. By reducing the armature travel speed; the armature experiences a reduction in magnitude of armature bounce allowing the armature to settle down quicker and produce minimum controllable injection events with shorter dwell times than predecessor fuel injectors, especially for close coupled post injection events.

Abstract: A mechanically actuated electronically controlled fuel injector includes a first electrical actuator that controls the position of a spill value, and a second electrical actuator to control pressure on a closing hydraulic surface associated with a nozzle check valve. The fuel injector is actuated via rotation of a cam to move a plunger to displace fuel from a fuel pressurization chamber either to a spill passage or at high pressure out of a nozzle outlet of the fuel injector for an injection event. Pressure in the fuel injector is moderated when the plunger is moving and the nozzle check valve is in a closed position by briefly cracking open the spill valve to relieve some pressure during the dwell between injection events, such as between a large main injection event and a small close coupled post injection event. This strategy allows for longer dwell times between injection events as well as smaller injection quantities in the post-injection.

Abstract: A mechanically actuated electronically controlled fuel injector (MEUI) includes a first electrical actuator that controls the position of a spill valve, and a second electrical actuator to control pressure on a closing hydraulic surface associated with a directly operated needle valve. The fuel injector is actuated via rotation of a cam to move a plunger to displace fuel from a fuel pumping chamber either to a spill passage, or at high pressure out of a nozzle outlet of the fuel injector for an injection event. The minimum controllable fuel injection quantity, especially as it relates to small closely coupled post injections following a large main injection, is accomplished by the inclusion of a variable flow rate valve that restricts fluid flow from a needle control chamber toward a drain, but is relatively unrestricted to high pressure fluid flow toward the needle control chamber.

Abstract: A mechanically actuated electronically controlled fuel injector includes a first electrical actuator that controls the position of a spill value, and a second electrical actuator to control pressure on a closing hydraulic surface associated with a nozzle check valve. The fuel injector is actuated via rotation of a cam to move a plunger to displace fuel from a fuel pressurization chamber either to a spill passage or at high pressure out of a nozzle outlet of the fuel injector for an injection event. Pressure in the fuel injector is moderated when the plunger is moving and the nozzle check valve is in a closed position by briefly cracking open the spill valve to relieve some pressure during the dwell between injection events, such as between a large main injection event and a small close coupled post injection event. This strategy allows for longer dwell times between injection events as well as smaller injection quantities in the post-injection.

Abstract: A seal arrangement for a needle valve in a fuel injector (100) includes a nozzle housing (122) forming an outer cavity (216) and defining a needle valve seat (218). A plurality of nozzle openings (204) are formed in the nozzle housing (122) and arranged symmetrically around its centerline at a first radial distance (RI). An outer needle valve (104) is reciprocally mounted in the outer cavity (216) and has a seat portion (224) arranged to abut the needle valve seat (218) when the outer needle valve (104) is seated or closed. A first ledge (502) formed on the seat portion (224) of the outer needle valve (104) sealably contacts the needle valve seat (218) along a first line contact seal (220) and a second ledge (508) formed on the seat portion (224) of the outer needle valve (104) sealably contacts the needle valve seat (218) along a second line contact seal (222).