Abstract: Methods and fluid supply systems are provided for supplying fluids while adjusting a pump discharge pressure to compensate for downstream pressure changes. The fluid supply system comprises a variable displacement piston (VDP) pump configured to supply a fluid at a pump discharge pressure, fuel metering units (FMUs) downstream of the VDP pump, each of the FMUs configured to receive the fluid from the VDP pump at the pump discharge pressure and supply the fluid at metered flow discharge pressures, and a pump compensator valve fluidically coupled with the FMUs to receive the fluid therefrom at the metered flow discharge pressures and configured to continuously, either fluidically or mechanically, adjust the pump discharge pressure of the VDP pump between a higher of a minimum pump discharge pressure and a floating ceiling pump discharge pressure, the floating ceiling pump discharge pressure based on a highest of the metered flow discharge pressures.

Abstract: An electrohydraulic poppet valve device control system includes a main body, an extend poppet valve, a retract valve body, a retract poppet valve, and an actuator. The actuator is movable to an extend position, a retract position, and a null position, and moves to, or remains in, the null position when electrical power is not supplied to the actuator. In the extend position, the extend poppet valve is in its open position and the retract poppet valve is in its closed position. In the retract position, the extend poppet valve is in its closed position and the retract poppet valve is in its open position. In the null position, the extend poppet valve is in its closed position and the retract poppet valve is in its closed position.

Abstract: A piston pump includes a ported member that is moveably disposed within an internal space of a housing between a rotating group and the housing. The ported member includes a first face facing the rotating group and a second face facing a fluid inlet and outlet. The ported member includes an intake port and a discharge port. Moreover, the ported member includes a balance aperture configured to pass fluid between the biasing member and a pump chamber as the rotating group rotates within the internal space such that the biasing member biases the ported member toward a balanced position within the internal space. The balance aperture has a rim at the first face. The rim is clefted at a relief feature of the first face. The relief feature is recessed into the first face.

Abstract: An electrohydraulic poppet valve device control system includes an extend valve body, an extend poppet valve, a retract valve body, a retract poppet valve, and an actuator. The actuator is movable to an extend position, a retract position, and a null position, and moves to, or remains in, the null position when electrical power is not supplied to the actuator. In the extend position, the extend poppet valve is in its open position and the retract poppet valve is in its closed position. In the retract position, the extend poppet valve is in its closed position and the retract poppet valve is in its open position. In the null position, the extend poppet valve is in its closed position and the retract poppet valve is in its closed position.

Abstract: Embodiments of a combined overspeed and fuel stream selector system are provided. In an embodiment, the assembly includes a conduit network, a Discharge Select Valve (DSV), and a shutoff valve. The DSV is fluidly coupled to a primary fuel inlet, a secondary fuel inlet, and a primary fuel outlet included in the conduit network. The shutoff valve is fluidly coupled between the primary fuel inlet and the primary fuel outlet. In a standard operation mode, the shutoff valve is maintained in an open position, while fuel received at the primary fuel inlet is directed through the shutoff valve, through the DSV, and to the primary fuel inlet. Conversely, in a backup operation mode, the shutoff valve is closed to block fuel flow from the primary fuel inlet to the primary fuel outlet, while the DSV directs fuel flow received at the secondary fuel inlet to the primary fuel outlet.

Abstract: A piston pump includes a rotor member with a bore therein. The bore is defined by an inner surface. The piston pump also includes a piston supported for reciprocating movement in an axial direction within the bore to change a volume of a pump chamber that is cooperatively defined by the piston and the rotor member. The piston has an outer surface that faces the inner surface with a leakage interface defined therebetween. The leakage interface is configured to receive a passive leakage flow of a fluid from the pump chamber through the leakage interface to provide cooling. Moreover, the outer surface includes a relief feature that is recessed into the outer surface to define, with the inner surface, a cooling pocket of the leakage interface. The cooling pocket moves in the axial direction relative to the inner surface with the reciprocating movement of the piston.

Abstract: A piston pump includes a ported member that is moveably disposed within an internal space of a housing between a rotating group and the housing. The ported member includes a first face facing the rotating group and a second face facing a fluid inlet and outlet. The ported member includes an intake port and a discharge port. Moreover, the ported member includes a balance aperture configured to pass fluid between the biasing member and a pump chamber as the rotating group rotates within the internal space such that the biasing member biases the ported member toward a balanced position within the internal space. The balance aperture has a rim at the first face. The rim is clefted at a relief feature of the first face. The relief feature is recessed into the first face.

Abstract: An electrohydraulic servo valve (EHSV) includes a housing assembly, a spool valve, an armature, a control mechanism, and a feedback spring. The spool valve is movably disposed within the housing assembly. The armature is rotationally mounted on the housing assembly. The control mechanism is coupled to the armature and is rotatable therewith. The feedback spring is coupled between the control mechanism and the spool valve, and includes a helical coil that is disposed on and engages the control mechanism, and a cantilever portion that extends from the helical portion to a terminus that engages the spool valve.

Abstract: Embodiments of a combined overspeed and fuel stream selector system are provided. In an embodiment, the assembly includes a conduit network, a Discharge Select Valve (DSV), and a shutoff valve. The DSV is fluidly coupled to a primary fuel inlet, a secondary fuel inlet, and a primary fuel outlet included in the conduit network. The shutoff valve is fluidly coupled between the primary fuel inlet and the primary fuel outlet. In a standard operation mode, the shutoff valve is maintained in an open position, while fuel received at the primary fuel inlet is directed through the shutoff valve, through the DSV, and to the primary fuel inlet. Conversely, in a backup operation mode, the shutoff valve is closed to block fuel flow from the primary fuel inlet to the primary fuel outlet, while the DSV directs fuel flow received at the secondary fuel inlet to the primary fuel outlet.

Abstract: A two-position, two-stage servo valve includes a valve body, a valve element, a control pressure chamber, and a control element. The valve body has an inner surface that defines a valve element chamber that includes a first control chamber and a second control chamber. The first control chamber is larger than the second control chamber. The valve element has first and second ends and is disposed within the valve element chamber and is movable between a first valve position and a second valve position. The first end is larger than the second end and is disposed within the first control chamber, and the second end is disposed within the second control chamber. The control pressure chamber includes a control pressure port that is in continuous fluid communication with the first control chamber. The control element is movable between a first control position and a second control position.

Abstract: A two-position, two-stage servo valve includes a valve body, a valve element, a control pressure chamber, and a control element. The valve body has an inner surface that defines a valve element chamber that includes a first control chamber and a second control chamber. The first control chamber is larger than the second control chamber. The valve element has first and second ends and is disposed within the valve element chamber and is movable between a first valve position and a second valve position. The first end is larger than the second end and is disposed within the first control chamber, and the second end is disposed within the second control chamber. The control pressure chamber includes a control pressure port that is in continuous fluid communication with the first control chamber. The control element is movable between a first control position and a second control position.

Abstract: A gas turbine engine fuel supply system includes a primary gear pump, a secondary gear pump, and a pump bypass valve. The primary gear pump always actively delivers fuel to the downstream fuel system, and is sized to supply 100% of the burn flow needed at a select low demand condition. The secondary gear pump is sized to make up the remainder of the flow at high demand conditions, and actively delivers fuel to the downstream fuel system only during those conditions. To supply discharge fuel pressures in excess of gear pump capability, a supercharger pump is disposed upstream of the primary and secondary gear pumps. The pump bypass valve is configured to regulate fuel pressure at the primary gear pump outlet to one of a plurality of preset differential pressures above one of a plurality of fuel load pressures and prevents reverse pressurization of the gear pumps.

Abstract: A torque motor valve actuator includes a first magnetic pole piece, a second magnetic pole piece, an armature, and a coil. The first magnetic pole piece is of a first magnetic polarity. The second magnetic pole piece is of a second magnetic polarity, and is spaced apart from the first magnetic pole piece to define a gap. The armature is rotationally mounted and disposed in the gap between the first and second magnetic pole pieces. The coil surrounds at least a portion of the armature and is disposed such that it is not surrounded by either the first magnetic pole piece or the second magnetic pole piece. The coil is adapted to receive electric current and is configured, upon receipt thereof, to generate a magnetic force that causes the armature to rotate.

Abstract: Methods and apparatus are provided for lubricating a piston-to-shoe interface in a hydraulic motor or pump. Piston assemblies are installed in a housing that are each adapted to receive a reciprocating drive force and are each configured, in response thereto, to cyclically move between an intake direction and a discharge direction. Each piston assembly includes a piston and a piston shoe, and the piston, the piston shoe, or both have a plurality of pockets formed in a surface that defines a piston-to-shoe interface. When the pistons cyclically move, liquid is supplied to each piston-to-shoe interface to form a hydrostatic bearing at each piston-to-shoe interface. A portion of the liquid that is supplied to each piston-to-shoe interface is selectively supplied to and from one or more of the plurality of pockets.

Abstract: A system provides “fail fixed” functionality and allows a user to manually manipulate fuel flow to a gas turbine engine in the unlikely event the primary control means is unavailable. The fuel metering unit includes a fuel metering valve, a flow increase valve, and a flow decrease valve. The flow increase valve and flow decrease valves are both in fluid communication with the fuel metering valve and are each adapted to selectively receive fuel flow commands from a primary fuel flow command source and from a secondary fuel flow command source. The flow increase and decrease valves are responsive to the fuel flow commands to selectively control the position of the fuel metering valve.

Abstract: A torque motor valve actuator includes a first magnetic pole piece, a second magnetic pole piece, an armature, and a coil. The first magnetic pole piece is of a first magnetic polarity. The second magnetic pole piece is of a second magnetic polarity, and is spaced apart from the first magnetic pole piece to define a gap. The armature is rotationally mounted and disposed in the gap between the first and second magnetic pole pieces. The coil surrounds at least a portion of the armature and is disposed such that it is not surrounded by either the first magnetic pole piece or the second magnetic pole piece. The coil is adapted to receive electric current and is configured, upon receipt thereof, to generate a magnetic force that causes the armature to rotate.

Abstract: A gas turbine engine fuel control system is provided that includes a fuel metering valve and a thrust control valve. The fuel metering valve includes a metering valve inlet and a metering valve outlet. The metering valve inlet is adapted to receive a flow of fuel, and is configured to control the flow of fuel through the metering valve outlet. The thrust control valve is adapted to receive thrust control valve override signals and is configured, in response thereto, to move from a first position, in which flow from the metering valve is not impacted, and a second position, in which flow from the metering valve is blocked while flow through a fixed-area orifice is allowed.

Abstract: A fuel return valve and system includes a flow-level select and shut-off valve and a servo control valve. The flow-level select and shut-off valve includes a first fuel inlet, a second fuel inlet, a return-to-tank fuel outlet, and a valve element movable between a shut-off position, a mid-flow position, and a max-flow position. The servo control valve is coupled to the flow-level select and shut-off valve and is configured to control relative fluid pressures therein to selectively move the valve element to the shut-off position, the mid-flow position, and the max-flow position.

Abstract: A gas turbine engine fuel supply system includes a primary gear pump, a secondary gear pump, and a pump bypass valve. The primary gear pump always actively delivers fuel to the downstream fuel system, and is sized to supply 100% of the burn flow needed at a select low demand condition. The secondary gear pump is sized to make up the remainder of the flow at high demand conditions, and actively delivers fuel to the downstream fuel system only during those conditions. To supply discharge fuel pressures in excess of gear pump capability, a supercharger pump is disposed upstream of the primary and secondary gear pumps. The pump bypass valve is configured to regulate fuel pressure at the primary gear pump outlet to one of a plurality of preset differential pressures above one of a plurality of fuel load pressures and prevents reverse pressurization of the gear pumps.

Abstract: A system provides “fail fixed” functionality and allows a user to manually manipulate fuel flow to a gas turbine engine in the unlikely event the primary control means is unavailable. The fuel metering unit includes a fuel metering valve, a flow increase valve, and a flow decrease valve. The flow increase valve and flow decrease valves are both in fluid communication with the fuel metering valve and are each adapted to selectively receive fuel flow commands from a primary fuel flow command source and from a secondary fuel flow command source. The flow increase and decrease valves are responsive to the fuel flow commands to selectively control the position of the fuel metering valve.