Abstract: An electro hydrostatic actuator comprises a hydraulic pump driven by an electric motor to supply hydraulic fluid to a hydraulic actuator. The pump comprises an inlet and an outlet for the hydraulic fluid and an active flow path arranged therebetween such that, in an active mode of operation when the pump is driven by the electric motor, hydraulic fluid is actively drawn in through the inlet and exhausted out through the outlet. The pump further comprises a bypass flow path arranged to open between the inlet and outlet such that, in a damping mode of operation when the pump is not driven by the electric motor, hydraulic fluid is able to pass through the pump along the bypass flow path between the inlet and outlet.

Abstract: A damping assembly is described herein for use in a device having moving aerodynamic surfaces including a first component comprising a back iron and at least one permanent magnet, said at least one permanent magnet providing a first magnetic field, and an electrically conductive second component, said electrically conductive second component and said first component being positioned coaxially about a central axis with said at least one permanent magnet being positioned between said back iron of said first component and said electrically conductive second component; the assembly further comprising means for rotating one or both of said at least one permanent magnet of said first component and said electrically conductive second component about said central axis to cause relative rotational movement between the at least one permanent magnet and second component, to thereby induce a variable magnetic flux in said electrically conductive second component and cause eddy currents to develop.

Abstract: A damping assembly is described herein for use in a device having moving aerodynamic surfaces including a first component comprising a back iron and at least one permanent magnet, said at least one permanent magnet providing a first magnetic field, and an electrically conductive second component, said electrically conductive second component and said first component being positioned coaxially about a central axis with said at least one permanent magnet being positioned between said back iron of said first component and said electrically conductive second component; the assembly further comprising means for rotating one or both of said at least one permanent magnet of said first component and said electrically conductive second component about said central axis to cause relative rotational movement between the at least one permanent magnet and second component, to thereby induce a variable magnetic flux in said electrically conductive second component and cause eddy currents to develop.

Abstract: An electro hydrostatic actuator (EHA) comprises a hydraulic pump and an electric motor driving the hydraulic pump. The hydraulic pump comprises an inlet and an outlet for hydraulic fluid and an active fluid flow path arranged therebetween such that, in an active mode of operation when the pump is driven by the electric motor, hydraulic fluid is actively drawn in through the inlet and exhausted out through the outlet. The hydraulic pump further comprises a bypass flow path arranged between the pump inlet and outlet, such that, in a damping mode of operation, hydraulic fluid is able to freely flow between the inlet and outlet in either direction.

Abstract: An electrical motor including a stator, said stator comprising a back iron, a plurality of teeth extending therefrom, and windings wound around said teeth; a rotary body comprising permanent magnets positioned between said stator and said rotary body; said rotary body being coaxially rotatable relative to the stator about a central axis; means for rotating said rotary body about said central axis of rotation relative to said stator, and wherein said back iron of said stator further comprises a first loop of electrical resistive wire extending therein.

Abstract: Method for controlling and damping the motion of a hydraulic actuator in an electro hydrostatic actuator (EHA) system comprising an electric motor, a hydraulic pump and a hydraulic fluid circuit connecting the hydraulic pump and the hydraulic actuator includes comprising: energising the electric motor to drive the hydraulic pump to supply hydraulic fluid to the hydraulic actuator through the hydraulic fluid circuit in an active mode of operation; providing a flow path between the hydraulic actuator and the hydraulic pump in a damping mode of operation such that hydraulic fluid can flow via the flow path through the hydraulic pump when the hydraulic actuator is driven by an external force; and determining a desired amount of damping to be applied to the hydraulic actuator in the damping mode of operation and providing the electric motor with one or more energy consuming means configured to provide the desired amount of damping.

Abstract: A flight control actuator drive including a first motor for providing a first rotational input, a second motor for providing a second rotational input and a speed summing device for combining the first and second rotational inputs into a rotational output for controlling an actuator. The speed summing device comprises first and second input gears to which the first and second motors are connected via first and second irreversible gears so that the first and second input gears can each transmit power in one direction only. The speed summing device may be a planetary gear assembly.

Abstract: An electro hydrostatic actuator (EHA) comprises a hydraulic pump and an electric motor driving the hydraulic pump. The hydraulic pump comprises an inlet and an outlet for hydraulic fluid and an active fluid flow path arranged therebetween such that, in an active mode of operation when the pump is driven by the electric motor, hydraulic fluid is actively drawn in through the inlet and exhausted out through the outlet. The hydraulic pump further comprises a bypass flow path arranged between the pump inlet and outlet, such that, in a damping mode of operation, hydraulic fluid is able to freely flow between the inlet and outlet in either direction.

Abstract: An electro hydrostatic actuator comprises a hydraulic pump driven by an electric motor to supply hydraulic fluid to a hydraulic actuator. The pump comprises an inlet and an outlet for the hydraulic fluid and an active flow path arranged therebetween such that, in an active mode of operation when the pump is driven by the electric motor, hydraulic fluid is actively drawn in through the inlet and exhausted out through the outlet. The pump further comprises a bypass flow path arranged to open between the inlet and outlet such that, in a damping mode of operation when the pump is not driven by the electric motor, hydraulic fluid is able to pass through the pump along the bypass flow path between the inlet and outlet.

Abstract: An electrical motor including a stator, said stator comprising a back iron, a plurality of teeth extending therefrom, and windings wound around said teeth; a rotary body comprising permanent magnets positioned between said stator and said rotary body; said rotary body being coaxially rotatable relative to the stator about a central axis; means for rotating said rotary body about said central axis of rotation relative to said stator, and wherein said back iron of said stator further comprises a first loop of electrical resistive wire extending therein.

Abstract: A damping assembly is described herein for use in a device having moving aerodynamic surfaces including a first component comprising a back iron and at least one permanent magnet, said at least one permanent magnet providing a first magnetic field, and an electrically conductive second component, said electrically conductive second component and said first component being positioned coaxially about a central axis with said at least one permanent magnet being positioned between said back iron of said first component and said electrically conductive second component; the assembly further comprising means for rotating one or both of said at least one permanent magnet of said first component and said electrically conductive second component about said central axis to cause relative rotational movement between the at least one permanent magnet and second component, to thereby induce a variable magnetic flux in said electrically conductive second component and cause eddy currents to develop.

Abstract: A flight control actuator drive including a first motor for providing a first rotational input, a second motor for providing a second rotational input and a speed summing device for combining the first and second rotational inputs into a rotational output for controlling an actuator. The speed summing device comprises first and second input gears to which the first and second motors are connected via first and second irreversible gears so that the first and second input gears can each transmit power in one direction only. The speed summing device may be a planetary gear assembly.

Abstract: A power supply system comprises first electrical conversion means for converting an alternating current electrical output from a generator to a direct current electrical output for supply to an electrically powered motor, second electrical conversion means for converting a direct current electrical output from a battery to a direct current electrical output for supply to the motor, and control means operable in the event of an interruption in the output from the first electrical conversion means to supply power from the second electrical conversion means to the motor.

Abstract: An actuator arrangement comprises a first linear actuator 12 having a first output shaft 14, a second linear actuator 16 having a second output shaft 18, the first and second output shafts 14, 18 being pivotally connected to a link 20, and a pivotable output connection 26 provided on the link 20 intermediate the locations at which the first and second output shafts 14, 18 are pivotally connected to the link 20.

Abstract: This assisted selection system comprises an electrohydraulic actuator (12) which controls the input element of the gearbox and may itself be controlled by parameters provided by the engine control computer. The actuator (12) comprises a group of solenoid valves (34, 35, 37, 52, 53) connected to cylinders (15, 16, 41, 42) controlling a fork selecting shaft (13). The cylinders (15, 16) may cause the rotation of the shaft (13) by means of a rocker (14) for selecting the fork corresponding to the chosen ratio, and cause the shaft (13) to move in translation so as to engage the chosen ratio by displacement of the selected fork. This automatic selecting system, which is also applicable to gearboxes of the barrel type, permits, when coupled with the engine control computer, the driver to avoid effecting the declutching and clutching operations, while enabling him to fully master his selection of the speed, if he desires, with no loss due to slip.

Abstract: This assisted selection system comprises an electrohydraulic actuator (12) which controls the input element of the gearbox and may itself be controlled by parameters provided by the engine control computer. The actuator (12) comprises a group of solenoid valves (34, 35, 37, 52, 53) connected to cylinders (15, 16, 41, 42) controlling a fork selecting shaft (13). The cylinders (15, 16) may cause the rotation of the shaft (13) by means of a rocker (14) for selecting the fork corresponding to the chosen ratio, and cause the shaft (13) to move in translation so as to engage the chosen ratio by displacement of the selected fork. This automatic selecting system, which is also applicable to gearboxes of the barrel type, permits, when coupled with the engine control computer, the driver to avoid effecting the declutching and clutching operations, while enabling him to fully master his selection of the speed, if he desires, with no loss due to slip.