Abstract: A system includes a first pump connected to an inlet line and connected to a first outlet line for supplying a first sub-system over a first pressure schedule. A second pump is connected to the inlet line and connected to a second outlet line for supplying a second subsystem over a second pressure schedule. A backup selector is in fluid communication with the first and second outlet lines. The backup selector is configured to switch to a first backup mode to supply the first sub-system from the second pump upon failure of the first pump. The backup selector is configured to switch to a second backup mode to supply the second sup-system from the first pump upon failure of the second pump.

Abstract: A fuel system includes a main pump assembly. The main pump assembly has a main fuel pump connected to an input line, a recirculation pump connected to the input line, and a fuel recirculation system. A recirculation control includes a first selector valve in fluid communication with an outlet line of the recirculation pump, with a recirculation return line connected to return fuel to the input line, and with an inter-valve line. The recirculation control includes a second selector valve in fluid communication with the inter-valve line, with a back-up line connecting the second selector valve to a main fuel control, and with a cooler recirculation line connected to supply the one or more coolers.

Abstract: A fuel supply system includes a pump to be connected to a fuel tank. A metering valve is downstream of the pump. A control is programmed to control at least one of the pump and metering valve. The control is operable to take in a flow demand signal and a fuel pressure signal from a controller associated with a gas turbine engine. The flow demand signal is indicative of a desired flow volume and the fuel pressure signal is indicative of a desired fuel pressure. Operation conditions are identified for the at least one of said pump and the metering valve. A gas turbine engine and fuel supply system is also disclosed.

Abstract: A fuel pump system includes a main fuel pump between a system fuel inlet and a system fuel outlet, a fuel flow path at least partially defined between the main fuel pump and the system fuel outlet, and a support fuel pump between the system fuel inlet and the system fuel outlet. The support fuel pump is sized to provide more flow to the system fuel outlet, when in an active state, than the main fuel pump. The system includes a valve assembly in fluid communication with the support fuel pump configured and adapted to connect the support fuel pump to the system fuel outlet, and a pressure regulating valve in fluid communication with the fuel flow path between the main fuel pump and the system fuel outlet. The system includes an EHSV in fluid communication with the fuel flow path between the PRV and the system fuel outlet.

Abstract: A pump system for a gas turbine engine including a first pump connected to a fluid flow demand line for delivering fluid to a fluid flow demand and a second pump connected, in parallel to the first pump, to the fluid flow demand line and supplementing fluid to the actuation or burner system based on the fluid flow demand. A pressure regulating valve (PRV) is fluidly connected to the flow demand line for bypassing flow to a pump inlet pressure of the first pump and second pump, and controlling a modulated pressure flow signal to a bypass valve, wherein the bypass valve is in fluid communication with the second pump and the PRV for receiving modulated pressure from the PRV and regulating delivery of fluid from the second pump to a bypass flow line.

Abstract: A fuel supply system includes a pump to be connected to a fuel tank. A metering valve is downstream of the pump. A control is programmed to control at least one of the pump and metering valve. The control is operable to take in a flow demand signal and a fuel pressure signal from a controller associated with a gas turbine engine. The flow demand signal is indicative of a desired flow volume and the fuel pressure signal is indicative of a desired fuel pressure. Operation conditions are identified for the at least one of said pump and the metering valve. A gas turbine engine and fuel supply system is also disclosed.

Abstract: A dual pump fuel delivery system for an aircraft includes a fixed displacement fuel pump including an inlet and an outlet. The fixed displacement fuel pump is configured to supply a first portion of a fuel demand for the aircraft. A variable displacement fuel pump including an inlet portion and an outlet portion includes a selectively adjustable pump actuator configured to supply a second portion of the fuel demand. The second portion is variable. A fuel demand sensor operates to detect a selected fuel demand. A control member is operatively connected to the fuel demand sensor and the variable displacement fuel pump. The control member being configured to operate to adjust the variable displacement fuel pump to output the second portion of the fuel demand to satisfy the selected fuel demand.

Abstract: A pump system for a gas turbine engine including a first pump connected to a fluid flow demand line for delivering fluid to a fluid flow demand and a second pump connected, in parallel to the first pump, to the fluid flow demand line and supplementing fluid to the actuation or burner system based on the fluid flow demand. A pressure regulating valve (PRV) is fluidly connected to the flow demand line for bypassing flow to a pump inlet pressure of the first pump and second pump, and controlling a modulated pressure flow signal to a bypass valve, wherein the bypass valve is in fluid communication with the second pump and the PRV for receiving modulated pressure from the PRV and regulating delivery of fluid from the second pump to a bypass flow line.

Abstract: In accordance with at least one aspect of this disclosure, a variable displacement pump system can include, a variable displacement pump disposed in a main line and configured to supply pressure to receive a low pressure fluid and to output a high pressure fluid. The main line can connect a hydraulic fluid source to a plurality of system actuators, where the variable displacement pump is disposed in the main line between the hydraulic fluid source and the plurality of system actuators to pressurize the hydraulic fluid.

Abstract: A variable positive displacement pump actuator system for a variable positive displacement pump can include a supply line configured to provide a supply pressure, a main pump line configured to provide a pump pressure greater than the supply pressure from the variable positive displacement pump, and at least one electro-hydraulic servo valve (EHSV) in fluid communication with the supply line and the main pump line to receive the supply pressure and the pump pressure. The at least one electro-hydraulic servo valve can be configured to output a first regulated pressure and a second regulated pressure.

Abstract: A pump system for a gas turbine engine including a first pump connected to a fluid flow demand line for delivering fluid to a fluid flow demand and a second pump connected, in parallel to the first pump, to the fluid flow demand line and supplementing fluid to the actuation or burner system based on the fluid flow demand. A pressure regulating valve (PRV) is fluidly connected to the flow demand line for bypassing flow to a pump inlet pressure of the first pump and second pump, and controlling a modulated pressure flow signal to a bypass valve, wherein the bypass valve is in fluid communication with the second pump and the PRV for receiving modulated pressure from the PRV and regulating delivery of fluid from the second pump to a bypass flow line.

Abstract: A method of controlling an actuation pump including monitoring a supply pressure of a pump, monitoring an outlet pressure of the pump, commanding a motor by a motor controller, which receives the monitored pressures, to drive the pump at a speed based on a comparison of the supply pressure and the outlet pressure of the pump.

Abstract: A fuel metering system includes a pump with an inlet and an outlet, a first flow path including a first valve fluidically connected to the outlet of the pump, and a second flow path including a second valve fluidically connected to the outlet of the pump, a third valve, and a fourth valve. An electrohydraulic servo valve in a first position hydraulically connects the inlet of the pump to the first, third, and fourth valves to close the first valve, open the third valve, open a first window of the fourth valve, and close a second window of the fourth valve. The electrohydraulic servo valve in a second position hydraulically connects the outlet of the pump to the first, third, and fourth valves to open the first valve, close the third valve, close the first window of the fourth valve, and open the second window of the fourth valve.

Abstract: A bolt configured for preventing loss of the bolt during removal can include a bolt head, a bolt shaft extending from the bolt head in an axial direction, the bolt shaft including threads, and a bolt capture channel defined through the bolt head and the bolt shaft in the axial direction. The bolt capture channel can include a head opening and shaft opening.

Abstract: The present disclosure provides an arm catcher system for an aircraft ejection seat. The arm catcher system may comprise a first support member configured to rotate in a first direction to be deployed in response to an ejection event and a first persistent locking mechanism coupled to the first support member, wherein the first persistent locking mechanism is configured to allow the support member to rotate in the first direction and configured to prevent the first support member from rotating in a second direction opposite the first direction.

Abstract: The present disclosure provides an arm catcher system for an aircraft ejection seat. The arm catcher system may comprise a first support member configured to rotate in a first direction to be deployed in response to an ejection event and a first persistent locking mechanism coupled to the first support member, wherein the first persistent locking mechanism is configured to allow the support member to rotate in the first direction and configured to prevent the first support member from rotating in a second direction opposite the first direction.

Abstract: A bolt configured for preventing loss of the bolt during removal can include a bolt head, a bolt shaft extending from the bolt head in an axial direction, the bolt shaft including threads, and a bolt capture channel defined through the bolt head and the bolt shaft in the axial direction. The bolt capture channel can include a head opening and shaft opening.

Abstract: Embodiments include an apparatus and techniques for operating an electromagnetic cartridge seal. Embodiments include operating a cartridge seal in one of a plurality of modes, and receiving a signal at a force applying mechanism of the cartridge seal, the force applying mechanism being coupled to a primary sealing component of the cartridge seal. Embodiments also include controlling the force applying mechanism based at least in part on the received signal.

Abstract: A bearing structure for abutting a pair of gears of a gear pump includes a body including a face on which the gears rotate, an inlet defined in the body, and an outlet defined in the body. The bearing structure includes a sealing portion of the face configured to fluidly seal the inlet from the outlet, the sealing portion being defined as a portion of the face in sealing engagement with the gears at a rotational position of the gears wherein a volume contained by teeth of the gears and the face is constant or about constant as the gears rotate.

Abstract: Embodiments include an apparatus and techniques for operating an electromagnetic cartridge seal. Embodiments include operating a cartridge seal in one of a plurality of modes, and receiving a signal at a force applying mechanism of the cartridge seal, the force applying mechanism being coupled to a primary sealing component of the cartridge seal. Embodiments also include controlling the force applying mechanism based at least in part on the received signal.