Abstract: A duel fuel quill assembly and method for assembling such an assembly for an engine are disclosed. The dual fuel quill assembly may comprise a cylinder head including a main bore and a receiving cavity, an outer quill tube, an inner quill tube nested within the outer quill tube, an adapter slidingly received inside the main bore of the cylinder head, and a manifold secured to the adapter. The adapter may be moveable between a first position and a second position and may define an axial bore configured to receive the outer quill tube and the nested inner quill tube. The manifold may define a recess configured to compress the outer and inner quill tubes against the cylinder head cavity when the adapter is in the second position.

Abstract: A pressure regulator for use in an engine is disclosed. The pressure regulator may include first and second flow paths formed in a body, wherein the first flow path is configured to pass a first fluid and the second flow path is configured to receive a second fluid. A diaphragm may be disposed within the first flow path and the diaphragm may be configured to move based on a pressure differential between the first and second fluids. The pressure regulator may further include a seat associated with the first flow path. A primary valve element may be connected to the diaphragm and configured to selectively engage the seat when a pressure of the fluid in the first flow path exceeds a pressure of the fluid in the second flow path by a first threshold amount.

Abstract: A compression ignition dual fuel engine supplies natural gas fuel and liquid diesel fuel to each engine cylinder from a common fuel injector. Each fuel injector is fluidly connected to both a liquid fuel common rail and a gaseous fuel common rail. The engine includes a surplus gas system for capturing surplus gas, such as evaporated gas from the gaseous fuel supply and pressure control system, or left over pressurized natural gas produced by engine shut down. Rather than being vented to atmosphere, the surplus gas can be burned in the engine when operating conditions present burn opportunities.

Abstract: A dual fuel system for an engine includes a plurality of fuel injectors that each include an injector body with a tip component defining a plurality of gas nozzle outlets and a plurality of liquid nozzle outlets positioned for direct injection into one of the engine cylinders. Each of the fuel injectors is fluidly connected to a gaseous fuel common rail through a quill and an outer passage defined between an inner tube and an outer tube. Each of the fuel injectors is fluidly connected to a liquid fuel common rail through the quill and an inner passage defined by the inner tube. Each combination of an inner tube and outer tube extend into the engine housing between the quill and one of the fuel injectors. Each of the inner tubes extends through one of the outer tubes and is compressed between a conical seat on the quill and a conical seat on one of the fuel injectors.

Abstract: A dual fuel compression ignition engine operates by injecting gaseous fuel and liquid diesel fuel from a common fuel injector directly into each engine cylinder. The gaseous fuel is ignited by compression igniting a small pilot injection quantity of the liquid diesel fuel. Evaporated natural gas from a cryogenic tank and/or a fuel conditioning module is dosed into an intake manifold of the engine with an electronically controlled supply valve. The electronically controlled supply valve may open to supply evaporated gas to the intake manifold contingent upon combustion conditions in the engine cylinder demonstrating a low risk of methane slip, and the dosing quantities are limited to reduce risk of ignition of an air/gas mixture in the intake manifold.

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: A system for controlling leakage of diesel fuel into the natural gas side of a dual fuel injector during low pressure natural gas conditions comprises a leakage control valve that blocks the diesel fuel line during very low natural gas line pressure conditions, including start-up and limp-home mode conditions.

Abstract: A dual fuel injector includes a liquid needle valve member guided to move in and out of contact with a first valve seat positioned between a liquid nozzle chamber and a liquid nozzle outlet set. A gas needle valve member is guided to move in and out of contact with a second valve seat positioned between a gas nozzle chamber and a gas nozzle outlet set. A hydraulic lock seal for inhibiting migration of gas fuel from the gas nozzle chamber into the first fuel includes an annular volume surrounding a guide segment of the gas needle valve member. The annular volume is fluidly connected to the liquid nozzle volume by a seal passage. A check valve positioned in the seal passage may close when a gas fuel supply is exhausted and an engine utilizing the dual fuel injector operates in a limp home single fueling mode.

Abstract: A dual fuel common rail system includes first and second common rails fluidly connected to a fuel injector by a co-axial quill assembly. Distillate diesel fuel at a first pressure moves from the first common rail through a first fuel passage defined by a quill, through an inner tube and into the fuel injector. Liquid natural gas a second lower pressure moves from the second common rail through a second fuel passage defined by the quill, through a space between the outer tube and the inner tube, and finally into the fuel injector. The quill is partially positioned in a block. First and second compression load adjusters are threadably attached to the block to adjust a compression load on the inner tube and outer tube to inhibit leakage of fuel from the tubes.

Abstract: A dual fuel common rail fuel injector includes a first and second check needle used to selectively inject two different fuels such as diesel and liquefied natural gas. The fuel injector includes a fuel separator disposed in the interior cavity of the first check needle and is in sealing contact with the nozzle. The fuel separator is configured to prevent commingling of the diesel fuel and the liquefied natural gas. The fuel injector also includes at least one sealing member that is configured to prevent the diesel fuel from leaking from the diesel fuel check cavity into a gaseous fuel orifice.

Abstract: The present disclosure is directed to a fuel circuit of a fuel injector that includes a first channel, a second channel, and a valve. The first channel is configured to receive a first fuel and define a flow path for the first fuel. The second channel is configured to receive a second fuel and define a flow path for the second fuel. The valve is in fluid communication with the first channel and the second channel. The valve is adapted to direct the second fuel to the first channel when a pressure in the first channel reaches a predetermined level.

Abstract: A dual fuel system includes a plurality of fuel injectors that each have a non-injection configuration, a liquid fuel injection configuration, a gaseous fuel injection configuration and a combined fuel injection configuration. Each of the fuel injectors includes a liquid control valve member with a guide segment that defines a portion of a leak path from the a liquid fuel inlet to a drain outlet, and a gas control valve member with a guide segment that defines a second leak path from the liquid fuel inlet to the drain outlet. Each injector body includes a tip component that defines both a liquid nozzle outlet set and a gas nozzle outlet set. A dual solenoid actuator has a first armature coupled to the liquid control valve member, a second armature coupled to the gas control valve member, and a shared stator.

Abstract: A dual fuel system includes a dual fuel injector that has disposed therein a gaseous nozzle chamber fluidly connected to a gaseous fuel inlet, and a liquid nozzle chamber fluidly connected to the liquid fuel inlet. The dual fuel injector also includes a hydraulic lock seal with an annular volume of liquid fuel surrounding a guide segment of a gas needle valve member for inhibiting migration of gaseous fuel into the liquid fuel. A liquid fuel common rail is fluidly connected to a liquid fuel inlet. A check valve is fluidly positioned between the gaseous fuel common rail and the gaseous nozzle chamber of the dual fuel injector for blocking liquid fuel leaked into a gaseous nozzle chamber through the hydraulic lock seal from entering the gaseous fuel common rail.

Abstract: A dual fuel injector includes a liquid needle valve member guided to move in and out of contact with a first valve seat positioned between a liquid nozzle chamber and a liquid nozzle outlet set. A gas needle valve member is guided to move in and out of contact with a second valve seat positioned between a gas nozzle chamber and a gas nozzle outlet set. A hydraulic lock seal for inhibiting migration of gas fuel from the gas nozzle chamber into the first fuel includes an annular volume surrounding a guide segment of the gas needle valve member. The annular volume is fluidly connected to the liquid nozzle volume by a seal passage. A check valve positioned in the seal passage may close when a gas fuel supply is exhausted and an engine utilizing the dual fuel injector operates in a limp home single fueling mode.

Abstract: A fuel injector includes an injector body that defines a fuel inlet, a drain outlet and a nozzle outlet, and has disposed therein a nozzle chamber, a needle control chamber and a valve chamber. The needle control chamber is fluidly connected to the drain outlet through a drain passage that includes the conical seat, is fluidly connected to the nozzle chamber through a Z orifice, and fluidly connected to the valve chamber through an A orifice. The nozzle chamber is fluidly connected to the valve chamber by a pressure passage that includes an F orifice that opens through a flat seat. A control valve member is trapped to move between contact with conical seat and contact with the flat seat. An electrical actuator is operable to push the control valve member away from the conical seat toward the flat seat when energized. A direct control needle valve has an opening hydraulic surface positioned in the nozzle chamber and a closing hydraulic surface positioned in the needle control chamber.

Abstract: A duel fuel quill assembly and method for assembling such an assembly for an engine are disclosed. The dual fuel quill assembly may comprise a cylinder head including a main bore and a receiving cavity, an outer quill tube, an inner quill tube nested within the outer quill tube, an adapter slidingly received inside the main bore of the cylinder head, and a manifold secured to the adapter. The adapter may be moveable between a first position and a second position and may define an axial bore configured to receive the outer quill tube and the nested inner quill tube. The manifold may define a recess configured to compress the outer and inner quill tubes against the cylinder head cavity when the adapter is in the second position.

Abstract: A dual fuel injector may be used to injector both gas and liquid fuel into a cylinder of a compression ignition engine. An injector body defines a first set of nozzle outlets, a second set of nozzle outlets, a first fuel inlet and a second fuel inlet. A dual solenoid actuator includes a first armature, a first coil, a second armature and a second coil that share a common centerline. The dual solenoid actuator has a non-injection configuration at which the first armature is at an un-energized position and the second armature is at an un-energized position. The dual solenoid actuator has a first fuel injection configuration at which the first fuel inlet is fluidly connected to the first set of nozzle outlets, the first armature is at an energized position and the second armature is at the un-energized position.

Abstract: A dual fuel injector may be used to injector both gas and liquid fuel into a cylinder of a compression ignition engine. An injector body defines a first set of nozzle outlets, a second set of nozzle outlets, a first fuel inlet and a second fuel inlet. A dual solenoid actuator includes a first armature, a first coil, a second armature, a second coil and a lever. The dual solenoid actuator has a non-injection configuration at which the first armature is in an un-energized position, the second armature is at un-energized position and the lever is at a first angular orientation. A dual solenoid actuator has a first fuel injection configuration at which the first fuel inlet is fluidly connected to the first set of nozzle outlets, the first armature is at an energized position, the second armature is at the un-energized position and the lever is at the first angular orientation.

Abstract: A dual fuel system for an engine includes a plurality of fuel injectors that each include an injector body with a tip component defining a plurality of gas nozzle outlets and a plurality of liquid nozzle outlets positioned for direct injection into one of the engine cylinders. Each of the fuel injectors is fluidly connected to a gaseous fuel common rail through a quill and an outer passage defined between an inner tube and an outer tube. Each of the fuel injectors is fluidly connected to a liquid fuel common rail through the quill and an inner passage defined by the inner tube. Each combination of an inner tube and outer tube extend into the engine housing between the quill and one of the fuel injectors. Each of the inner tubes extends through one of the outer tubes and is compressed between a conical seat on the quill and a conical seat on one of the fuel injectors.

Abstract: A dual fuel common rail system includes first and second common rails fluidly connected to a fuel injector by a co-axial quill assembly. Distillate diesel fuel at a first pressure moves from the first common rail through a first fuel passage defined by a quill, through an inner tube and into the fuel injector. Liquid natural gas a second lower pressure moves from the second common rail through a second fuel passage defined by the quill, through a space between the outer tube and the inner tube, and finally into the fuel injector. The quill is partially positioned in a block. First and second compression load adjusters are threadably attached to the block to adjust a compression load on the inner tube and outer tube to inhibit leakage of fuel from the tubes.