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 fuel system of an aircraft engine, having: a boost pump having an input and an output; one or more selector valves; a first component pump having an input fluidly coupled to the output of the boost pump and an output of the first component pump is configured to direct fuel to a first component via the one or more selector valves; and a second component pump having an input that is selectively coupled to either the input or the output of the boost pump by the one or more selector valves, and an output of the second component pump is fluidly coupled to a second component and selectively coupled to the first component by the one or more selector valves.

Abstract: A two stage fuel delivery system for an aircraft includes a first stage pump including an inlet connected to a source of fuel and an outlet connected to a combustor assembly, and a second stage pump including an inlet portion connected to the source of fuel and an outlet portion connected to the combustor assembly. A bypass valve is connected between the source of fuel, the inlet, and the inlet portion. The bypass valve selectively disconnects the second stage pump from the source of fuel. A metering valve is connected to the inlet and the inlet portion. The metering valve includes a metering valve inlet and a metering valve outlet. A pressure regulating valve is connected to the metering valve. A stage monitoring system is configured to detect a change in operation of the second stage and control the bypass valve.

Abstract: A fuel system of an aircraft engine, having: a boost pump having an input and an output; one or more selector valves; a first component pump having an input fluidly coupled to the output of the boost pump and an output of the first component pump is configured to direct fuel to a first component via the one or more selector valves; and a second component pump having an input that is selectively coupled to either the input or the output of the boost pump by the one or more selector valves, and an output of the second component pump is fluidly coupled to a second component and selectively coupled to the first component by the one or more selector valves.

Abstract: A fuel system can include a selection and shutoff valve (SSOV) configured to allow a primary flow having a primary flow pressure to pass therethrough in a first state such that the primary flow can travel to an output line. The SSOV can also be configured to shut off the primary flow in a second state to prevent the primary flow from travelling to the output line. In the second state, the SSOV can be configured to allow a secondary flow from a secondary flow source to pass therethrough such that the secondary flow can travel to the output line.

Abstract: Hydraulic actuator systems of aircraft are described. The hydraulic actuator systems include a hydraulic actuator having a housing and piston therein. The piston includes a piston head separating the housing into a retract cavity and an extend cavity. An actuator controller is hydraulically coupled to the retract cavity by a first hydraulic line and hydraulically coupled to the extend cavity by a second hydraulic line and configured to control a hydraulic pressure within each of the retract cavity and the extend cavity to control actuation of the hydraulic actuator. A position-lock controller is arranged along at least one of the first hydraulic line and the second hydraulic line, the position-lock controller is configured to hydraulically decouple the actuator controller from at least one of the retract cavity and the extend cavity.

Abstract: A solenoid driven actuator system includes a first solenoid having at least one pressure input and a pressure outlet downstream from the at least one pressure input. The system includes a second solenoid having at least one pressure input and a pressure outlet downstream from the at least one pressure input. The system includes a pressure-switching valve operatively coupled to the first and second solenoids. The system includes an actuator operatively coupled to the pressure outlet of the second solenoid.

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 hydraulic actuator system includes a hydraulic actuator having a housing with a piston having a piston shaft arranged within the housing. The housing is formed to have first, second and third regions, wherein the first region is between the second and third regions and has a larger major dimension than the second and third regions. The system also includes first, second, and third piston heads connected to the piston shaft with the first piston head being tween the second and third piston, wherein the first position head is within the first region and divides the first region into two volumes, the second piston head is in the second region and defines a first volume and the third piston head is in the third region and defines a fourth volume. The system also includes a mode selection device operably connected to the first, second, third and fourth volume.

Abstract: A hydraulic actuator system of an aircraft includes a hydraulic actuator having a housing with a piston having a piston shaft with a piston head attached thereto and arranged within the housing. The piston head divides in internal volume of the housing into an extend cavity and a retract cavity and the extend cavity is configured to be connected to low pressure fluid source. The system also includes a pressure selector unit fluidly connected to the retract cavity and configured to be connected to the low pressure fluid source and to a high pressure fluid source. The unit include three solenoids with the first and second connected in parallel to the fluid sources and the third solenoid having a third solenoid first input connected to the first solenoid output, a third solenoid second input connected to the second solenoid output, and a third solenoid output connected to the retract cavity.

Abstract: Hydraulic actuator systems of aircraft are described. The hydraulic actuator systems include a hydraulic actuator having a housing and piston therein. The piston includes a piston head separating the housing into a retract cavity and an extend cavity. An actuator controller is hydraulically coupled to the retract cavity by a first hydraulic line and hydraulically coupled to the extend cavity by a second hydraulic line and configured to control a hydraulic pressure within each of the retract cavity and the extend cavity to control actuation of the hydraulic actuator. A position-lock controller is arranged along at least one of the first hydraulic line and the second hydraulic line, the position-lock controller is configured to hydraulically decouple the actuator controller from at least one of the retract cavity and the extend cavity.

Abstract: A fluid flow system includes a main valve having a spool, a first chamber, and a second chamber. A pressure difference between the first chamber and the second chamber is configured to move the spool to control fluid flow. An electromechanical meter interface device (EMID) is in fluid communication with at least one of the first and second chambers of the main valve. The EMID is configured to meter fluid from a first source and a second source to the at least one of the first chamber and the second chamber. The first source has a different pressure from the second source. A fixed orifice is arranged between the main valve and the EMID. A fuel system for a gas turbine engine is also disclosed.

Abstract: A solenoid driven actuator system includes a first solenoid having at least one pressure input and a pressure outlet downstream from the at least one pressure input. The system includes a second solenoid having at least one pressure input and a pressure outlet downstream from the at least one pressure input. The system includes a pressure-switching valve operatively coupled to the first and second solenoids. The system includes an actuator operatively coupled to the pressure outlet of the second solenoid.

Abstract: A solenoid driven actuator system includes a first solenoid having at least one pressure input and a pressure outlet downstream from the at least one pressure input. A second solenoid has at least one pressure input and a pressure outlet downstream from the at least one pressure input. A transfer solenoid operatively coupled to the first and second solenoids. An actuator valve operatively coupled to a pressure outlet of the transfer solenoid.

Abstract: A pumping system includes a first variable displacement pump having a first inlet and a first outlet. The first outlet is fluidically connected to a system outlet. A first actuator is mechanically coupled to a first displacement mechanism of the first variable displacement pump A second variable displacement pump includes a second inlet and a second outlet. The second outlet is fluidically connected to the system outlet. The pumping system also includes a second actuator mechanically coupled to a second displacement mechanism of the second variable displacement pump. An electrohydraulic servo valve is hydraulically connected to the first and second actuators. An electronic engine controller is in communication with the electrohydraulic servo valve and is configured to send electrical current to the electrohydraulic servo valve to drive the first actuator and the second actuator.

Abstract: In accordance with at least one aspect of this disclosure, a pump selector system can include a primary pump fluidly connected to provide a primary flow to a fluid destination, a secondary pump fluidly connected to provide a secondary flow to the fluid destination, and a selector valve disposed downstream of the primary pump and the secondary pump. The selector valve can be configured to toggle between a first position configured to allow flow from the primary pump to flow to the fluid destination and to block flow from the secondary pump to the fluid destination, and a second position configured to allow flow from the secondary pump to flow to the fluid destination and to block flow from the primary pump to the fluid destination.

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 fuel system can include a selection and shutoff valve (SSOV) configured to allow a primary flow having a primary flow pressure to pass therethrough in a first state such that the primary flow can travel to an output line. The SSOV can also be configured to shut off the primary flow in a second state to prevent the primary flow from travelling to the output line. In the second state, the SSOV can be configured to allow a secondary flow from a secondary flow source to pass therethrough such that the secondary flow can travel to the output line.

Abstract: An actuator includes a housing, a first chamber inside the housing, a cylinder within the housing, and a second chamber within the housing. The cylinder fluidically isolates the first chamber from the second chamber. The actuator also includes a rod connected to the cylinder and extending through the second chamber and the housing. A shell is spaced apart from the housing and defines a fluid gap between the shell and the housing. The shell includes a shell inlet fluidically connected to the fluid gap and a shell outlet fluidically connected to the fluid gap.

Abstract: In accordance with at least one aspect of this disclosure, a pump selector system can include a primary pump fluidly connected to provide a primary flow to a fluid destination, a secondary pump fluidly connected to provide a secondary flow to the fluid destination, and a selector valve disposed downstream of the primary pump and the secondary pump. The selector valve can be configured to toggle between a first position configured to allow flow from the primary pump to flow to the fluid destination and to block flow from the secondary pump to the fluid destination, and a second position configured to allow flow from the secondary pump to flow to the fluid destination and to block flow from the primary pump to the fluid destination.