Abstract: A valve spool may include a cylindrical spool body having a spool longitudinal axis, a first spool body end wall and a second spool body end wall disposed axially opposite the first spool body end wall, and a spool outer surface. The spool outer surface may include a first spool guide region proximate the first spool body end wall and having a spool guide region outer diameter, a second spool guide region proximate the second spool body end wall and having the spool guide region outer diameter, and a spool tight clearance region disposed between the first spool guide region and the second spool guide region. The spool tight clearance region may have a spool tight clearance region outer diameter that is greater than the spool guide region outer diameter.

Abstract: A hydraulic piston pump includes a reciprocal piston disposed in a blind housing bore of a piston housing to generate a pumping action. To accommodate the piston, a piston cartridge is installed in each of the housing bores. The piston cartridge includes a piston sleeve having an inner sleeve periphery, a first outer sleeve periphery, and a second outer sleeve periphery. The inner sleeve periphery is configured to establish sliding contact with the piston. The first outer sleeve periphery has a first outer sleeve diameter that is larger than a second outer sleeve diameter of the second outer sleeve periphery. To seal against the blind housing bore, a liner cap having a cylindrical liner wall and an axial liner cover is disposed over the first outer sleeve periphery. The axial liner cover abuts a housing bore ceiling of the blind housing bore and can receive hydraulic fluid there through.

Abstract: A cryogenic pump system includes a supply of liquid natural gas, a source of hydraulic fluid, a cryogenic pump, and an electronic control module. The cryogenic pump is operatively arranged with the supply of liquid natural gas and the source of hydraulic fluid. The cryogenic pump is configured to operate using the source of hydraulic fluid to compress at least some of the supply of liquid natural gas for delivery to an engine. The electronic control module is operably arranged with the cryogenic pump and configured to selectively operate the cryogenic pump. Control strategies for operating the cryogenic pump system are disclosed which have reduced power demands.

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 pump is disclosed having a manifold with an inlet, a pressure outlet, and a return outlet. The pump may also have a jacket connected to an end of the manifold to create an enclosure that is in fluid communication with the inlet of the manifold, and at least one pumping mechanism extending from the manifold into the jacket. The at least one pumping mechanism may have an inlet open to the enclosure and an outlet in communication with the pressure outlet of the manifold. The pump may further have a standpipe extending from the manifold into the enclosure. The standpipe may be in communication with the return outlet of the manifold.

Abstract: A method for controlling a stroke velocity in a pump includes using a sensor to detect a start of a pump stroke and an end of the pump stroke. A stroke time is calculated, the stroke time being a time period between the start of the pump stroke and the end of the pump stroke. The stroke velocity is calculated based on a stroke length and the stroke time. The stroke velocity is compared to a reference stroke velocity. A hydraulic supply pressure to the pump is increased if the calculated stroke velocity is less than the reference stroke velocity, and the hydraulic supply pressure is decreased if the calculated stroke velocity is more than the reference stroke velocity.

Abstract: A hydraulic piston pump includes a piston disposed in a blind housing bore of a piston housing and that reciprocates to generate a pumping action. To accommodate the piston, a piston cartridge is installed in each of the housing bores. The piston cartridge includes a piston sleeve having an inner sleeve periphery, a first outer sleeve periphery, and a second outer sleeve periphery. The inner sleeve periphery is configured to establish sliding contact with the piston. The first outer sleeve periphery has a first outer sleeve diameter that is larger than a second outer sleeve diameter associated with the second outer sleeve periphery. To seal against the blind housing bore, a liner cap having a cylindrical liner wall and an axial liner cover is disposed over the first outer sleeve periphery. The axial liner cover abuts a housing bore ceiling of the blind housing bore and can receive hydraulic fluid there through.

Abstract: A valve spool may include a cylindrical spool body having a spool longitudinal axis, a first spool body end wall and a second spool body end wall disposed axially opposite the first spool body end wall, and a spool outer surface. The spool outer surface may include a first spool guide region proximate the first spool body end wall and having a spool guide region outer diameter, a second spool guide region proximate the second spool body end wall and having the spool guide region outer diameter, and a spool tight clearance region disposed between the first spool guide region and the second spool guide region. The spool tight clearance region may have a spool tight clearance region outer diameter that is greater than the spool guide region outer diameter.

Abstract: A drive system for a cryogenic pump is provided including a spool housing having a plurality of valves disposed therein about a pump axis and a tappet housing including a plurality of tappet bores, each tappet bore in communication with a respective one of the plurality of valves. A collection cavity collects hydraulic fluid from the tappet bores. A pump flange includes a fluid inlet and a fluid outlet. An inlet manifold directs hydraulic fluid received through the fluid inlet to each of the plurality of valves. An outlet manifold directs hydraulic fluid from each of the valves and the collection cavity to the fluid outlet.

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: A pump has a plurality of pumping elements, each being independently responsive to an actuation signal from a controller. The controller is programmed to maintain a desired pressure at the pump discharge, monitor the fluid pressure at the pump discharge, compare the fluid pressure with the desired fluid pressure to determine a pressure error, provide commands to sequentially actuate the pumping elements when the pressure error is within a threshold range, and provide commands to actuate more than one of the plurality of pumping elements simultaneously, such that more than one pumped amounts of fluid are delivered simultaneously at the pump discharge, when the pressure error droops outside of the threshold range.

Abstract: A dual fuel injector configuration is provided that includes a plurality of seals around a fuel check needle to prevent transfer of a gaseous fuel to portions of the injector intended for handling of liquid fuel, prevent transfer of liquid fuel to portions of the injector intended for handling of gaseous fuel, or a combination thereof. At least one seal can correspond to a pressure-assisted sealing member suitable for sealing against transfer of liquid fuel. At least one additional seal can correspond to a pressure-assisted sealing member suitable for sealing against transfer of gaseous fuel. The sealing members can be separated by a backing member that provides structural support for one or both of the sealing members. The volume occupied by the backing member can also include a conduit to an external surface of the injector.

Abstract: A drive system for a cryogenic pump is provided including a spool housing having a plurality of valves disposed therein about a pump axis and a tappet housing including a plurality of tappet bores, each tappet bore in communication with a respective one of the plurality of valves. A collection cavity collects hydraulic fluid from the tappet bores. A pump flange includes a fluid inlet and a fluid outlet. An inlet manifold directs hydraulic fluid received through the fluid inlet to each of the plurality of valves. An outlet manifold directs hydraulic fluid from each of the valves and the collection cavity to the fluid outlet.

Abstract: A cryogenic pump is disclosed as having a plunger housing with a plurality of barrels formed in a ring around a central axis, and a plurality of plungers. Each of the plurality of plungers may be reciprocatingly disposed within a different one of the plurality of barrels. The cryogenic pump may also include an inlet manifold connected to the plunger housing and having a plurality of bores. Each of the plurality of bores may be open to a corresponding one of the plurality of barrels. The cryogenic pump may also have at least one orifice in fluid communication with each of the plurality of bores, and an inlet check valve disposed between each of the plurality of bores and the at least one orifice. The inlet check valve may be movable to selectively allow flow between the at least one orifice and a corresponding one of the plurality of barrels.

Abstract: A method for controlling a stroke velocity in a pump includes using a sensor to detect a start of a pump stroke and an end of the pump stroke. A stroke time is calculated, the stroke time being a time period between the start of the pump stroke and the end of the pump stroke. The stroke velocity is calculated based on a stroke length and the stroke time. The stroke velocity is compared to a reference stroke velocity. A hydraulic supply pressure to the pump is increased if the calculated stroke velocity is less than the reference stroke velocity, and the hydraulic supply pressure is decreased if the calculated stroke velocity is more than the reference stroke velocity.

Abstract: A cryogenic pump system includes a supply of liquid natural gas, a source of hydraulic fluid, a cryogenic pump, and an electronic control module. The cryogenic pump is operatively arranged with the supply of liquid natural gas and the source of hydraulic fluid. The cryogenic pump is configured to operate using the source of hydraulic fluid to compress at least some of the supply of liquid natural gas for delivery to an engine. The electronic control module is operably arranged with the cryogenic pump and configured to selectively operate the cryogenic pump. Control strategies for operating the cryogenic pump system are disclosed which have reduced power demands.

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 pump has a plurality of pumping elements, each being independently responsive to an actuation signal from a controller. The controller is programmed to maintain a desired pressure at the pump discharge, monitor the fluid pressure at the pump discharge, compare the fluid pressure with the desired fluid pressure to determine a pressure error, provide commands to sequentially actuate the pumping elements when the pressure error is within a threshold range, and provide commands to actuate more than one of the plurality of pumping elements simultaneously, such that more than one pumped amounts of fluid are delivered simultaneously at the pump discharge, when the pressure error droops outside of the threshold range.

Abstract: A pump is disclosed having a manifold with an inlet, a pressure outlet, and a return outlet. The pump may also have a jacket connected to an end of the manifold to create an enclosure that is in fluid communication with the inlet of the manifold, and at least one pumping mechanism extending from the manifold into the jacket. The at least one pumping mechanism may have an inlet open to the enclosure and an outlet in communication with the pressure outlet of the manifold. The pump may further have a standpipe extending from the manifold into the enclosure. The standpipe may be in communication with the return outlet of the manifold.

Abstract: The present disclosure is related to a flow limiting system for a dual fuel engine is disclosed. The flow limiting system includes a first valve configured to regulate a flow of a liquid fuel therethrough based on a pressure difference across the first valve. The flow limiting system further includes a second valve configured to regulate a flow of a gaseous fuel therethrough based on a pressure difference across the second valve. The second valve includes a valve body movably provided within a valve chamber. The valve body includes a control orifice extending therethrough. The valve body also includes grooves defined on an outer surface thereof.