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. Pressure waves in the gaseous fuel common rail are damped in a pressure damping chamber of the co-axial quill assembly to promote consistent gaseous fuel injection rates and quantities from the fuel injector.

Abstract: A piston arrangement comprises a circumferential piston groove that can accommodate a seal for sealing between the piston and the cylinder bore when the piston moves in a reciprocal movement. The piston arrangement comprises a first fluid flow passage, defined at least in part by the piston body that fluidly connects the forward side of the cylinder bore with a space within the piston groove underneath the seal and a second fluid flow passage, defined in part by the piston body, which fluidly connects the rear side of the cylinder bore with the space within the piston groove underneath the seal. The two fluid flow passages allow a controlled fluid flow around the piston seal and comprise a channel provided in a lateral wall of the piston groove or an orifice provided in the piston body.

Abstract: A dual fuel engine utilizes a compression ignited pilot injection of liquid diesel fuel to ignite a mixture of gaseous fuel and air in each engine cylinder. The gaseous fuel is injected at a relatively low pressure directly into the engine cylinder from a fuel injector. The liquid diesel fuel is injected directly into the engine cylinder from the same fuel injector. In-cylinder dynamic gas blending during the compression stroke can reduce potential hydrocarbon slip that could occur when unburned fuel resides in crevice volumes within the engine cylinder.

Abstract: A pump has a pump body and at least first and second pumping elements, each pumping element including a piston defining a head-end and a rod-end. The pump receives a pressurized fluid at an inlet, and returns fluid through a drain outlet. A hydraulic distributor operates to fluidly connect the head end of an extending piston to the pressurized fluid, and the rod end of the extending piston to the drain outlet. The hydraulic distributor further connects the rod-end of a retracting piston to the drain outlet, and the rod-end of one or more retracting pistons to the drain or to a return pressure, which is lower than an extending pressure.

Abstract: A cryogenic fluid pump includes a plurality of pumping elements, each of the plurality of pumping elements having an actuator portion that is associated with and configured to selectively activate one end of a pushrod in response to a command by an electronic controller, an activation portion associated with an opposite end of the pushrod, and a pumping portion associated with the activation portion. For each of the plurality of pumping elements, the pumping portion is activated for pumping a fluid by the activation portion, which activation portion is activated by the actuator portion. The electronic controller is configured to selectively activate each of the plurality of pumping elements such that a flow of fluid from the cryogenic fluid pump results from continuous activations of the plurality of pumping elements at selected dwell times between activations of successive pumping elements.

Abstract: A compression ignition engine is fueled from common rail fuel injectors that predominately inject natural gas fuel that is compression ignited with a small pilot injection of liquid diesel fuel. Before and after a rapid load loss transient, the liquid and gaseous rail pressures are controlled toward respective pressures based upon engine speed and load. During the transient, the liquid rail pressure is controlled relative to the gas rail pressure in order to maintain the liquid rail pressure greater than the gas pressure during the transient to avoid migration gaseous fuel into the liquid fuel side of the system.

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 pump system is disclosed for use with a fuel system of an engine. The pump system may have a first pump with a first end, a second end, a reservoir located at the second end, and at least one pump mechanism configured to receive fluid from the reservoir. The pump system may also have a second pump mounted to the first pump at the second end and having at least one pump mechanism configured to discharge fluid into the reservoir of the first pump. The pump system may further have a mechanical input operatively connected to the at least one pump mechanism of each of the first and second pumps.

Abstract: A cryogenic pump is disclosed for use with a fuel system having a tank. The cryogenic pump may have a barrel, and a plunger configured to reciprocate within the barrel. The pump may also have an inlet configured to connect the tank to the barrel at a front side of the plunger, and an outlet connected to the barrel at the front side of the plunger. The pump may further have a vent line configured to extend from the barrel at a back side of the plunger to a location outside of the tank.

Abstract: A pump is disclosed for use in pressurizing a cryogenic fluid. The pump may have a barrel, and a boost enclosure disposed around the barrel. The pump may also have a boost plunger disposed inside the barrel and configured to discharge fluid into the boost enclosure. The pump may further have a main plunger disposed inside the barrel and configured to receive fluid from the boost enclosure and to increase a pressure of the fluid.

Abstract: A cryogenic pump comprising a shaft disposed in a bearing. The shaft rotates with respect to the bearing housing, and the shaft includes an end with an angled face. The pump includes a drive at one end of the bearing housing. A tappet passage is formed through the drive housing. A pushrod housing connects to the drive housing. The pump includes a piston and a tappet sliding within the tappet passage. The tappet has a base end disposed within the tappet passage and a rod end extending below the tappet end of the drive housing. A fluid cavity is in the tappet passage between the piston and the tappet. The pump includes a pushrod connected to the tappet. The angled face of the shaft rotates and drives the piston toward the drive housing, pushing fluid within the fluid cavity against the tappet, driving the pushrod away from the drive housing.

Abstract: A bearing arrangement for a wobble plate piston pump includes first, second, third, and fourth bearing assemblies. The first and second bearing assemblies support the drive shaft portion for rotation within the housing about the central longitudinal axis, while the third and fourth bearing assemblies support the load plate for rotation relative to the offset shaft portion of the shaft. The second bearing assembly is distally disposed from the first, the third disposed distally to second, and the fourth disposed distally to third. The fourth bearing assembly is the most distally disposed bearing assembly along the shaft.

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 dual fuel system for an engine is disclosed. The dual fuel system may have a first fuel supply providing a first fuel to the engine, and a second fuel supply providing a second fuel. The dual fuel system may also have a regulator configured to pass the second fuel from the second fuel supply to the engine, with the regulator also in fluid communication with the first fuel supply. The dual fuel system may further have a damper in fluid communication with the first fuel supply and an output of the regulator.

Abstract: A seal for a piston of a positive displacement pump includes an annular seal element, a radially outer surface of the annular seal element defining a longitudinal axis, and an annular energizer disposed between the annular seal element and the longitudinal axis along a radial direction. The annular energizer has a resilience along the radial direction to bias the annular seal element away from the longitudinal axis along the radial direction, the radial direction being perpendicular to the longitudinal axis.

Abstract: A fuel injector concurrently injects a liquid fuel and a gaseous fuel into a combustion chamber of an internal combustion engine. An interior wall of an injector body defines a control chamber and an injection chamber. A needle valve is disposed within the body and has a control surface fluidly communicating with the control chamber. A liquid fuel inlet fluidly communicates with the control chamber and a gaseous fuel inlet fluidly communicates with the injection chamber. A delivery passage is defined by at least one of the needle valve and the interior wall and configured to place the control chamber in fluid communication with the injection chamber to permit flow of liquid fuel therebetween.

Abstract: A dual fuel common rail system may be operated in a regular mode in which a relatively large charge of gaseous fuel is ignited by compression igniting a relatively small injection quantity of liquid diesel fuel. The dual fuel system may be operated in a single fuel limp home mode in which liquid diesel fuel is injected at higher pressures. Over pressurization of the gaseous fuel side of the fuel system due to leaked liquid fuel is avoided by regularly injecting leaked liquid fuel, but not gaseous fuel, from the gaseous nozzle outlet set during the limp home mode of operation.

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. Pressure waves in the gaseous fuel common rail are damped in a pressure damping chamber of the co-axial quill assembly to promote consistent gaseous fuel injection rates and quantities from the fuel injector.

Abstract: A dual fuel injector utilizes first and second control valves to open and close first and second nozzle outlet sets to inject a first fuel and a second fuel, respectively. The first and second control valves have concentric lines of action, and include a self alignment feature with respect to a flat seat. The two fuels may differ in at least one of chemical identity, matter phase and pressure.

Abstract: A gaseous fuel engine combines the efficiencies associated with high compression ratio engines with the attractiveness of fueling with natural gas. Each engine cylinder has an associated fuel injector positioned for direct injection and supplied with gaseous fuel from a high pressure common rail. A separate ignition prechamber is also supplied with natural gas and includes an ignition device. Hot gas generated by igniting a mixture of gaseous fuel and air in the prechamber are used to ignite a much larger charge of gaseous fuel injected into the engine cylinder from the fuel injector. The engine has a compression ratio greater than 14: to 1.