Abstract: A cryogenic fluid pump includes a drive assembly and a pumping assembly. The drive assembly includes a cylinder. The cylinder includes an annular dump channel formed in and extending about an interior wall of the cylinder. A piston is reciprocatable within the cylinder between a first and second position. A hydraulic pressure chamber is defined by the cylinder and the piston. The piston includes an axial spill passage in communication with the pressure chamber and a transverse spill passage in communication with the axial spill passage. The transverse spill passage includes a piston dump port which is sealed to the cylinder in the first position and in the second position unsealed to the cylinder to permit fluid exit from the pressure chamber. The second position includes an over travel state and the dump area of the piston dump port when unsealed to the cylinder increases as the piston advances.

Abstract: An electronically controlled fuel injector includes a reduced part count and complexity over similar fuel injectors without a substantial reduction in performance capabilities. This is accomplished by using a one-piece needle that is hydraulically balanced and biased toward a closed position with a spring positioned in the needle control chamber. Although subtle, this injector has some ability to control the fuel pressure when the needle valve is opening and closing by adjusting a relative timing of a pressure control valve opening relative to a needle control chamber, using separate electrical actuators. The disclosure is particularly applicable to fuel injectors that cycle through high and low pressure states during and between injection events, respectively. Cam actuated fuel injectors being particularly well suited.

Abstract: An electronically controlled fuel injector includes a reduced part count and complexity over similar fuel injectors without a substantial reduction in performance capabilities. This is accomplished by using a one-piece needle that is hydraulically balanced and biased toward a closed position with a spring positioned in the needle control chamber. Although subtle, this injector has some ability to control the fuel pressure when the needle valve is opening and closing by adjusting a relative timing of a pressure control valve opening relative to a needle control chamber, using separate electrical actuators. The invention is particularly applicable to fuel injectors that cycle through high and low pressure states during and between injection events, respectively. Cam actuated fuel injectors being particularly well suited.

Abstract: A fuel injector includes an auxiliary valve member that can assist in raising a mean injection pressure, increase a nozzle valve opening pressure, and hasten the closure rate of a nozzle valve member over an equivalent fuel injector without the auxiliary valve. The auxiliary valve member is fluidly positioned between a needle control chamber and a high pressure space, which includes a fuel pressurization chamber within the fuel injector. The auxiliary valve member includes a closing hydraulic surface exposed to fluid pressure in the high pressure space. The plumbing and the auxiliary valve member allow high pressure fuel to act upon a closing hydraulic surface of the nozzle valve member to increase valve opening pressure and mean injection pressure. The needle control chamber may be vented or may be a closed volume when the auxiliary valve member is in its closed position.

Abstract: Fuel injectors equipped with direct control needle valves can add new capabilities to a fuel injection system, but can sometimes have difficulty in achieving low hydrocarbon emissions at levels comparable to ancestor fuel injectors that utilize a simple spring biased needle. The present invention seeks lower hydrocarbon emissions by reducing fuel pressure before the direct control needle valve member has reached its closed position toward the end of an injection event. Reducing fuel pressure can be accomplished in a number of ways depending upon the particular fuel injection system, including spilling fuel pressure in a cam system or possibly relieving pressure on an intensifier piston.

Abstract: An electronically controlled fuel injector includes a reduced part count and complexity over similar fuel injectors without a substantial reduction in performance capabilities. This is accomplished by using a one-piece needle that is hydraulically balanced and biased toward a closed position with a spring positioned in the needle control chamber. Although subtle, this injector has some ability to control the fuel pressure when the needle valve is opening and closing by adjusting a relative timing of a pressure control valve opening relative to a needle control chamber, using separate electrical actuators. The invention is particularly applicable to fuel injectors that cycle through high and low pressure states during and between injection events, respectively. Cam actuated fuel injectors being particularly well suited.

Abstract: A fuel injector includes an auxiliary valve member that can assist in raising a mean injection pressure, increase a nozzle valve opening pressure, and hasten the closure rate of a nozzle valve member over an equivalent fuel injector without the auxiliary valve. The auxiliary valve member is fluidly positioned between a needle control chamber and a high pressure space, which includes a fuel pressurization chamber within the fuel injector. The auxiliary valve member includes a closing hydraulic surface exposed to fluid pressure in the high pressure space. The plumbing and the auxiliary valve member allow high pressure fuel to act upon a closing hydraulic surface of the nozzle valve member to increase valve opening pressure and mean injection pressure. The needle control chamber may be vented or may be a closed volume when the auxiliary valve member is in its closed position.

Abstract: A unit injector assembly is provided that helps to ensure maximum injection flow while minimizing the harmful affects of pressure waves within the unit injector assembly. The unit injector assembly has a first fuel passageway extending from the plunger piston pumping chamber to the tip check stem injection chamber and valve seat. The unit injector assembly has a second fuel passageway extending from the tip check stem injection chamber to a fuel control valve assembly. A flow restricting fuel passageway connects one of the pumping chamber and the first fuel passageway with the second fuel passageway and acts to minimize cavitation at the valve seat and effectively eliminates pressure waves within the unit injector assembly.

Abstract: A unit injector assembly is provided that helps to ensure maximum injection flow while minimizing the harmful affects of pressure waves within the unit injector assembly. The unit injector assembly has a first fuel passageway extending from the plunger piston pumping chamber to the tip check stem injection chamber and valve seat. The unit injector assembly has a second fuel passageway extending from the tip check stem injection chamber to a fuel control valve assembly. A flow restricting fuel passageway connects one of the pumping chamber and the first fuel passageway with the second fuel passageway and acts to minimize cavitation at the valve seat and effectively eliminates pressure waves within the unit injector assembly.

Abstract: Fuel injectors equipped with direct control needle valves can add new capabilities to a fuel injection system, but can sometimes have difficulty in achieving low hydrocarbon emissions at levels comparable to ancestor fuel injectors that utilize a simple spring biased needle. The present invention seeks lower hydrocarbon emissions by reducing fuel pressure before the direct control needle valve member has reached its closed position toward the end of an injection event. Reducing fuel pressure can be accomplished in a number of ways depending upon the particular fuel injection system, including spilling fuel pressure in a cam system or possibly relieving pressure on an intensifier piston.

Abstract: An engine valve actuator is provided. The engine valve actuator includes a first piston and a second piston. The second piston is moveably received within the first piston. The engine valve further includes an actuator body that has a bore defining a first stop and a second stop. The first stop is configured to engage the first piston to limit movement of the first piston at a first preselected distance of travel. The second stop is configured to engage the second piston to limit movement of the second piston at a second preselected distance. A valve element is operatively connected to the second piston to move in response to movement of the second piston.

Abstract: An actuator for adjusting a clearance between an end of a valve and an end of the actuator. The actuator has a piston therein having a central bore of which a portion is threaded. The piston has an end and has a flat defined near the end. The actuator has a stem member positioned therein. The stem member has a central portion which is threadedly positioned within the threaded portion of the central bore. The stem member defines a first end and a second end, and a threaded portion is located near the second end. The first end of the stem member and the end of the piston has a predetermined length which is adjustable. The predetermined length is adjusted by threadedly rotating the stem member relative to the piston. A locking device fixes the predetermined length during operation of the engine.

Abstract: An actuator for adjusting a clearance between an end of a valve and an end of the actuator. The actuator has a piston therein having a central bore of which a portion is threaded. The piston has an end and has a flat defined near the end. The actuator has a stem member positioned therein. The stem member has a central portion which is threadedly positioned within the threaded portion of the central bore. The stem member defines a first end and a second end, and a threaded portion is located near the second end. The first end of the stem member and the end of the piston has a predetermined length which is adjustable. The predetermined length is adjusted by threadedly rotating the stem member relative to the piston. A locking device fixes the predetermined length during operation of the engine.