Abstract: In accordance with at least one aspect of this disclosure, a pump includes a housing having one or more fluid inlets and one or more fluid outlets. The housing is configured to act as a pump housing for passing a fluid from the one or more fluid inlets to the one or more fluid outlets and configured to act as a stator for a motor. The pump also includes a cylinder encased within the housing and mounted on a shaft for rotation within the housing. The cylinder is configured to act as an impeller to drive fluid from the one or more fluid inlets through the housing to the one or more fluid outlets and configured to act as a rotor for the motor.

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: According to an aspect, a dual fuel pump system includes a primary run-dry fuel pump having multiple stages, each of the stages configured to produce fuel pressure between a pump stage inlet and a pump stage outlet, and at least one of the stages operable in a run-dry mode. A secondary run-dry fuel pump is operable in run-dry mode, where the secondary run-dry fuel pump is mechanically driven by an accessory gearbox of an engine of the aircraft. An electric motor is operably coupled to the primary run-dry fuel pump and configured to drive rotation of the stages of the primary run-dry fuel pump. A controller is configured to pressurize fuel using a single stage of the primary run-dry fuel pump, pressurize fuel using at least two stages of the primary run-dry fuel pump, and pressurize fuel using the secondary run-dry fuel pump under various operating conditions.

Abstract: In accordance with at least one aspect of this disclosure, a pump includes a housing having one or more fluid inlets and one or more fluid outlets. The housing is configured to act as a pump housing for passing a fluid from the one or more fluid inlets to the one or more fluid outlets and configured to act as a stator for a motor. The pump also includes a cylinder encased within the housing and mounted on a shaft for rotation within the housing. The cylinder is configured to act as an impeller to drive fluid from the one or more fluid inlets through the housing to the one or more fluid outlets and configured to act as a rotor for the motor.

Abstract: An actuation assembly includes a drive mechanism that has an array of magnetic members moveable along an axis, and a gear train that has an input and an output. The drive mechanism causes the input to move in response to generating an electromagnetic field that interacts with at least one of the array of magnetic members.

Abstract: A fuel system includes a fuel metering unit having a fuel inlet and a fuel outlet defining a flow path therebetween. The fuel system includes a bleed valve in fluid communication with the flow path of the fuel metering unit. The fuel system includes a controller in communication with the fuel metering unit and the bleed valve to send data thereto and/or receive data therefrom. The bleed valve is configured and adapted to open or close depending on a command from the controller. The flow path is configured and adapted to be in selective fluid communication with a fuel system interstage through the bleed valve.

Abstract: Systems and methods for position determination in an electric machine are provided. Aspects include a DC power source connected to an inverter circuit, an electric motor comprising a rotor and a stator, wherein an output of the inverter circuit is connected to a plurality phase of windings, and a controller configured to operate the electric motor and the inverter circuit, wherein the controller is further configured to determine one or more inactive phase windings from the plurality of phase windings, supply a voltage to the inactive phase windings, receive, from a current sensor connected to the electric motor, a current for each inactive phase winding of the inactive phase windings, determine an inductance for each inactive phase winding of the inactive phase winding based on the current, and determine a position of the rotor in the electric motor based on the inductance for each inactive phase winding.

Abstract: Systems and methods for position determination in an electric machine are provided. Aspects include a DC power source connected to an inverter circuit, an electric motor comprising a rotor and a stator, wherein an output of the inverter circuit is connected to a plurality phase of windings, and a controller configured to operate the electric motor and the inverter circuit, wherein the controller is further configured to determine one or more inactive phase windings from the plurality of phase windings, supply a voltage to the inactive phase windings, receive, from a current sensor connected to the electric motor, a current for each inactive phase winding of the inactive phase windings, determine an inductance for each inactive phase winding of the inactive phase winding based on the current, and determine a position of the rotor in the electric motor based on the inductance for each inactive phase winding.

Abstract: A heat exchanger is configured to adjust a flow restriction of flow passages through the heat exchanger in response to changes in temperature of elements that define at least a portion of the flow passages. The elements include a first material having a first coefficient of thermal expansion, and a second material having a second coefficient of thermal expansion that is different from the first coefficient of thermal expansion.

Abstract: A braking system is disclosed. In various embodiments, the braking system includes a brake stack; an actuator configured to apply a compressive load to the brake stack; a servo valve coupled to a power source and to the actuator; and a brake control unit configured to operate the servo valve at a current ramp rate in response to a pedal deflection signal, wherein the current ramp rate is determined via a relationship between the current ramp rate and a brake pressure command signal.

Abstract: A braking system including a brake actuator, a control valve, a control assembly, and at least one pressure sensor. The control valve is disposed to direct hydraulic fluid to the brake actuator at a rate corresponding to a magnitude of a control signal. The control assembly includes a mixed-mode control system. The at least one pressure sensor is configured to measure a pressure of the hydraulic fluid to the brake actuator. The control assembly is configured to determine a position of the brake actuator. The mixed-mode control system is configured to determine a position command and a pressure command. The mixed-mode control system is configured to adjust the magnitude of the control signal based on at least one of the position command and the pressure command so as to reposition the brake actuator from a first position to a second position.

Abstract: An electromechanical actuation motor includes a main housing, a series of stator windings, and a first circumferential row of fins. The series of stator windings is disposed inside of the main housing. The first circumferential row of fins is connected to and extends radially from an outer surface of the main housing. The main housing and the first circumferential row of fins are formed as a single piece of material via layer-by-layer additive manufacturing. Each fin of the first circumferential row of fins includes a first portion and a second portion. The first portion is integrally formed with and attached to the outer surface of the main housing at a first end of the first portion. The second portion is attached to and integrally formed with a second end of the first portion. The first portion intersects the second portion to form a T-shape.

Abstract: A fuel system for an aircraft can include one or more airframe fuel lines configured to transfer fuel from one or more fuel tanks to an engine, one or more engine fuel pumps in fluid communication with the one or more airframe fuel lines and configured to pressurize fuel from a main stage boost pressure to a combustor pressure to be injected into a combustor of an engine, one or more airframe fuel pumps configured to pressurize fuel within the one or more airframe fuel lines to the main stage boost pressure used by the engine fuel pump. For example, the main stage boost pressure can be about 250 psi.

Abstract: An actuation assembly includes a drive mechanism that has an array of magnetic members moveable along an axis, and a gear train that has an input and an output. The drive mechanism causes the input to move in response to generating an electromagnetic field that interacts with at least one of the array of magnetic members.

Abstract: A compound harmonic actuator includes a circular gear, a flex gear including permanent magnets and a coil assembly disposed and configured to generate a magnetic field with which the permanent magnets interact to deform the flex gear. The coil assembly is controllable such that the deformation of the flex gear is such that the flex gear engages with the circular gear resulting in flex gear rotation.

Abstract: A braking system including a brake actuator, a control valve, a control assembly, and at least one pressure sensor. The control valve is disposed to direct hydraulic fluid to the brake actuator at a rate corresponding to a magnitude of a control signal. The control assembly includes a mixed-mode control system. The at least one pressure sensor is configured to measure a pressure of the hydraulic fluid to the brake actuator. The control assembly is configured to determine a position of the brake actuator. The mixed-mode control system is configured to determine a position command and a pressure command. The mixed-mode control system is configured to adjust the magnitude of the control signal based on at least one of the position command and the pressure command so as to reposition the brake actuator from a first position to a second position.

Abstract: An embodiment of a linear motor assembly includes an armature extending linearly along an axis, the armature having a plurality of windings. The linear motor assembly also includes a magnetic assembly including a plurality of magnets arrayed in a loop configuration, a linear section of the plurality of magnets extending linearly through the plurality of windings in a direction parallel to the axis, each magnet of the linear section being oriented in the direction and configured to move in the direction due to interaction between the plurality of windings and a magnetic field generated by the magnetic assembly.

Abstract: An example electromagnetic actuator includes a drive shaft, a motor operable to rotate the drive shaft, and a load shaft coupled to an armature body. A clutch is operable to control whether the drive shaft engages the load shaft. A rotatable portion of the clutch corotates with the drive shaft and includes a field winding and a clutch body. A stationary portion of the clutch includes an exciter winding that is inductively coupled to the rotatable portion and is operable to energize the field winding. The field winding is operable, when energized, to provide a magnetic field that causes engagement or disengagement between the clutch body and an armature body. A method of operating an electromagnetic actuator is also disclosed.

Abstract: A braking system is disclosed. In various embodiments, the braking system includes a brake stack; an actuator configured to apply a compressive load to the brake stack; a servo valve coupled to a power source and to the actuator; and a brake control unit configured to operate the servo valve at a current ramp rate in response to a pedal deflection signal, wherein the current ramp rate is determined via a relationship between the current ramp rate and a brake pressure command signal.

Abstract: An example electromagnetic clutch assembly includes a rotatable portion and a stationary portion. The rotatable portion includes a field winding and a clutch body, and the stationary portion includes an exciter winding that is inductively coupled to the rotatable portion and is operable to energize the field winding. The field winding is operable, when energized, to provide a magnetic field that causes engagement or disengagement between the clutch body and an armature body. A method of operating an electromagnetic clutch assembly is also disclosed.