Abstract: A flight control surface actuation system includes a rotary actuator having an output part configured to rotate about an axis (R-R), a connecting rod for connecting a flight control surface to the rotary actuator, and a connection mechanism connecting a first end of the connecting rod to the output part such that rotation of the output part about the axis causes at least part of the connection rod to rotate about the axis. The connection mechanism comprises a connection structure fixed to the output part and an engagement part mounted for rotation about a longitudinal axis. The engagement part extends through the connecting rod and is fixed to it. A position sensor is arranged to measure the angular displacement of the first end of the connecting rod about the axis.

Abstract: An electromechanical actuator assembly operable in a plurality of modes. The EMA assembly includes: an electrical motor having a motor shaft extending along an axis (A) of the EMA, the motor driving the shaft to rotate about the axis; a gear assembly mounted around, and in geared connection with the shaft, to rotate with the shaft; an EMA output connected to the gear assembly such that rotation of the motor shaft causes rotation of the output via the gear assembly, the output rotating at a speed which is a predetermined fraction of the speed of rotation of the motor shaft based on the gear ratio of the gear assembly.

Abstract: A generic remote electronic unit, RUE, configured to provide control signals to selectively drive either one of a hydraulic actuator or an electric actuator. The generic REU includes circuit boards comprising command and monitoring circuits common to both hydraulic actuators and electric actuators, and being further configured to be programmed with software specific to an actuator to be controlled.

Abstract: A system for identifying a failure of the primary load path in an actuator. The system includes a first strain gauge configured to be mounted to a static portion and to measure vibrations of the static portion and a second strain gauge configured to be mounted to a nut assembly and to measure vibrations of the nut assembly. The system comprises a processor configured to identify a failure of the primary load path by comparing the measured vibrations of the static portion and the measured vibrations of the nut assembly.

Abstract: There is provided a lower attachment for a trimmable horizontal stabiliser actuator (THSA) for connecting the THSA to a flight control surface. The attachment includes: a nut assembly for providing a load path through the THSA to the flight control surface when the THSA is connected to the flight control surface. The nut assembly includes a nut for location on a screw shaft of the THSA, a failsafe plate for coupling to the flight control surface, and a transfer plate for transferring load between the failsafe plate and the nut. The nut assembly has a first unloaded configuration in which there is no contact between the nut and the transfer plate, and a second loaded configuration in which there is contact between a first pair of opposed surfaces of the nut and the transfer plate.

Abstract: A device for selectively transmitting torque between an input shaft and an output shaft includes: a first plurality of friction disks configured to rotate with the input shaft; a second plurality of friction disks configured to rotate with the output shaft and interdigitated with the first plurality of friction disks; a plurality of roller disks wherein each of the plurality of roller disks includes a first disk-to-roller interface with one of the first plurality of friction disks and a second disk-to-roller interface with one of the second plurality of friction disks; a first resilient member configured to provide a force (FSPR) through the first and second plurality of friction disks and roller disks; a solenoid configured to overcome the force (FSPR) from the resilient member when energised. the device may be selectively placed in one of a first mode and a second mode depending on torque requirements.

Abstract: An electromechanical actuator, EMA, having a plurality of modes. The EMA includes a housing, a motor fixed relative to the housing, the motor having an output shaft, the output shaft defining an axis (X) of the EMA and a first sun gear connected for rotation with the output shaft. The system includes an output arranged to be driven by rotation of the first sun gear, wherein the output is arranged to have a neutral position and to be movable away from the neutral position within a positive quadrant and away from the neutral position within a negative quadrant and a ratchet comprising a ratchet wheel and a pawl. The system also has a torque limiter having a predetermined torque limit and arranged to limit torque transfer between the first sun gear and the output.

Abstract: A system for identifying a failure of the primary load path in an actuator. The actuator includes a screw shaft and a nut assembly moveable along the screw shaft. The nut assembly comprises a primary nut for transmitting load through the actuator along a primary load path, and a secondary nut for transmitting load through the actuator along a secondary load path. The nut assembly is configured such that, in normal operation, the secondary nut is not engaged with the screw shaft and load is transmitted through the actuator along the primary load path, and such that, upon failure of the primary load path, the secondary nut is configured to engage the screw shaft and transmit load through the actuator along the secondary load path. The system includes a strain gauge configured to be mounted to the actuator and to measure vibrations of the actuator.

Abstract: A connector for adjustably connecting an RVDT (rotary variable differential transformer) and a reductor shaft. The connector includes a body defining a bore configured to receive the reductor shaft. The bore has an inner wall and a threaded tightening member which is substantially parallel to a main axis (AA, BB) of the bore. A portion of the body is configured to deform upon tightening of the tightening member such that, when the reductor shaft is received by the bore, the reductor shaft is gripped by at least a portion of the inner wall.

Abstract: A rotary electromechanical actuator (EMA) includes: a first EMA part comprising a first electric motor and a first rotary shaft (S1) extending along an axis and arranged to be rotated about the axis by the first electric motor, and a first 1st stage gearbox providing a geared transmission from the first electric motor to the first output shaft, and a first brake assembly for applying a braking force to the first output shaft; the EMA further comprising: a second EMA part comprising a second electric motor and a second rotary shaft (S2) extending along the axis and arranged to be rotated about the axis by the second electric motor, and a second 1st stage gearbox providing a geared transmission from the second electric motor to the second output shaft, and a second brake assembly for applying a braking force to the second output shaft.

Abstract: An accumulator assembly for providing hydraulic fluid to an electrohydrostatic actuator includes an accumulator for containing a supply of hydraulic fluid, the accumulator having an exit port via which hydraulic fluid can flow, in use, to the actuator. The assembly further includes an accumulator refill arrangement fluidly connected to a supply of hydraulic fluid for refilling the accumulator via a fluid line when a level of fluid in the accumulator is below a predetermined value. The accumulator includes a cylinder defining a fluid chamber and an accumulator piston moveable within the cylinder relative to the chamber responsive to the fluid pressure. The refill arrangement includes a spool moveable across the fluid line between an open position, wherein fluid can flow along the fluid line from the supply to the chamber, and a closed position, wherein the spool blocks the flow of fluid from the supply to the chamber.

Abstract: An electromechanical actuator (EMA) includes: a stationary body portion; a movable body portion configured to move relative to the stationary body portion; an actuation element connecting the stationary body portion and the movable body portion and configured to actuate the movable body portion relative to the stationary body portion; a surface acoustic wave (SAW) sensor disposed on the actuation element; a first interface component disposed on the stationary body portion at an interface between the stationary body portion and the movable body portion; and a second interface component disposed on the movable body portion at the interface between the stationary body portion and the movable body portion. The second interface component is configured to transmit signals between the SAW sensor and the first interface component. The first interface component and the second interface component define an inductive position sensor to determine the position of the second interface component.

Abstract: A system includes an electrically-actuated clutch arranged to selectively connect a shaft to a motor shaft. Ratchets brake the shaft against rotation in either direction when the output is not within either of the predetermined ranges. Thus, when the motor shaft is connected, via the clutch, to the shaft, the ratchets may act as a brake on the motor shaft.

Abstract: An assembly is provided for an aircraft. This aircraft assembly includes an aircraft control surface and a hydraulic actuator. The hydraulic actuator includes a housing and a piston within the housing. The housing is formed integral with the aircraft control surface.

Abstract: A connector for adjustably connecting an RVDT (rotary variable differential transformer) and a reductor shaft. The connector includes a body defining a bore configured to receive the reductor shaft. The bore has an inner wall and a threaded tightening member which is substantially parallel to a main axis (AA, BB) of the bore. A portion of the body is configured to deform upon tightening of the tightening member such that, when the reductor shaft is received by the bore, the reductor shaft is gripped by at least a portion of the inner wall.

Abstract: An electromechanical actuator (EMA) includes a plurality of modes and includes an electrical motor having a motor shaft extending along an axis (A) and that drives the shaft to rotate about the axis and a gear assembly mounted around, and in geared connection with the shaft, to rotate with the shaft. The EMA output is connected to the gear assembly such that rotation of the motor shaft causes rotation of the output via the gear assembly, the output rotating at a speed which is a predetermined fraction of the speed of rotation of the motor shaft based on the gear ratio of the gear assembly. The EMA also includes a synchroniser comprising a first conical portion connected to an end of the motor shaft, and a second conical portion connected to a ratchet. The synchroniser has an engaged position and a disengaged position.

Abstract: A flight control surface actuation system includes a rotary actuator having an output part configured to rotate about an axis (R-R), a connecting rod for connecting a flight control surface to the rotary actuator, and a connection mechanism connecting a first end of the connecting rod to the output part such that rotation of the output part about the axis causes at least part of the connection rod to rotate about the axis. The connection mechanism comprises a connection structure fixed to the output part and an engagement part mounted for rotation about a longitudinal axis. The engagement part extends through the connecting rod and is fixed to it. A position sensor is arranged to measure the angular displacement of the first end of the connecting rod about the axis.

Abstract: An electromechanical actuator assembly operable in a plurality of modes.

Abstract: There is provided a lower attachment for a trimmable horizontal stabiliser actuator (THSA) for connecting the THSA to a flight control surface. The attachment includes: a nut assembly for providing a load path through the THSA to the flight control surface when the THSA is connected to the flight control surface. The nut assembly includes a nut for location on a screw shaft of the THSA, a failsafe plate for coupling to the flight control surface, and a transfer plate for transferring load between the failsafe plate and the nut. The nut assembly has a first unloaded configuration in which there is no contact between the nut and the transfer plate, and a second loaded configuration in which there is contact between a first pair of opposed surfaces of the nut and the transfer plate.

Abstract: A device for selectively transmitting torque between an input shaft and an output shaft includes: a first plurality of friction disks configured to rotate with the input shaft; a second plurality of friction disks configured to rotate with the output shaft and interdigitated with the first plurality of friction disks; a plurality of roller disks wherein each of the plurality of roller disks includes a first disk-to-roller interface with one of the first plurality of friction disks and a second disk-to-roller interface with one of the second plurality of friction disks; a first resilient member configured to provide a force (FSPR) through the first and second plurality of friction disks and roller disks; a solenoid configured to overcome the force (FSPR) from the resilient member when energised. the device may be selectively placed in one of a first mode and a second mode depending on torque requirements.