An aircraft undercarriage having a leg for mounting to move on an aircraft structure between a deployed position and a retracted position is provided. The undercarriage generally includes a brace member arranged between the structure of the aircraft and the leg in order to stabilize the leg in the deployed position, and a drive actuator for moving the leg from the deployed position to the retracted position. The brace member includes a strut arm having a proximal end that is designed to be hinged on the structure of the aircraft. The arm presents a longitudinal slot extending until the slot reaches a distal end in order to terminate in a bend and having slidably engaged therein a finger that is secured to the leg, the drive actuator being coupled to the strut arm.

A landing gear including a shock strut assembly including an outer cylinder coupled to an airframe, a wheel movably coupled to the outer cylinder so as to reciprocate substantially along a longitudinal axis of the outer cylinder, and a shrink mechanism including a pivot arm pivotally coupled to the shock strut assembly, a drive member coupling the pivot arm to a landing gear retract mechanism, a driven member coupled to the pivot arm, a first shrink link member coupled to the pivot arm by the driven member, and a second shrink link member coupled to the first shrink link member and to the shock strut assembly. Rotation of the pivot arm by the drive member, effects a folding movement between the first shrink link member and the second shrink link member, and the folding movement effects at least a retraction of the wheel relative to the outer cylinder.

A landing gear including a shock strut assembly including an outer cylinder coupled to an airframe, a wheel movably coupled to the outer cylinder so as to reciprocate substantially along a longitudinal axis of the outer cylinder, and a shrink mechanism including a pivot arm pivotally coupled to the shock strut assembly, a drive member coupling the pivot arm to a landing gear retract mechanism, a driven member coupled to the pivot arm, a first shrink link member coupled to the pivot arm by the driven member, and a second shrink link member coupled to the first shrink link member and to the shock strut assembly. Rotation of the pivot arm by the drive member, effects a folding movement between the first shrink link member and the second shrink link member, and the folding movement effects at least a retraction of the wheel relative to the outer cylinder.

An aircraft assembly, having: a reference component; a first component and a first actuator, the first actuator configured to move the first component relative to the reference component; a second component and a second actuator, the second actuator configured to move the second component relative to the reference component; a position sensor configured to measure a position of the first component, and to output a position value, the sensor being capable of outputting a plurality of non-zero position values; and a controller configured to control the movement of the second component by the second actuator based at least partially on the position value output by the position sensor.

An aircraft assembly, having: a reference component; a first component and a first actuator, the first actuator configured to move the first component relative to the reference component; a second component and a second actuator, the second actuator configured to move the second component relative to the reference component; a position sensor configured to measure a position of the first component, and to output a position value, the sensor being capable of outputting a plurality of non-zero position values; and a controller configured to control the movement of the second component by the second actuator based at least partially on the position value output by the position sensor.

Systems and methods for enabling aircraft shock strut shrink are provided. The system may comprise a shock strut comprising a shrink piston, an accumulator comprising a gas piston and a hydraulic chamber, wherein the gas piston is configured to apply gas pressure to the hydraulic chamber, and a first valve in fluid communication with the accumulator. The system may further comprise a second valve, wherein the second valve is in fluid communication with a vent, the pneumatic cylinder, and the gas piston, wherein the first valve is in fluid communication with the hydraulic chamber and the shrink piston.

Systems and methods for enabling aircraft shock strut shrink are provided. The system may comprise a shock strut comprising a shrink piston, an accumulator comprising a gas piston and a hydraulic chamber, wherein the gas piston is configured to apply gas pressure to the hydraulic chamber, and a first valve in fluid communication with the accumulator. The system may further comprise a second valve, wherein the second valve is in fluid communication with a vent, the pneumatic cylinder, and the gas piston, wherein the first valve is in fluid communication with the hydraulic chamber and the shrink piston.

In general, certain embodiments of the present disclosure provide an electro-hydrostatic actuator comprising a piston assembly and a hydraulic cylinder. The piston assembly, having a piston head and a piston rod extending from the piston head, is located and movable within the hydraulic cylinder. The hydraulic cylinder includes a hydraulic fluid chamber region including a piston side chamber and a rod side chamber, a reservoir for storing hydraulic fluid located within the hydraulic cylinder which is in fluid communication with the hydraulic fluid chamber region. The electro-hydrostatic actuator includes a hydraulic pump system for moving hydraulic fluid in the reservoir and the hydraulic fluid chamber region, the hydraulic pump system in fluid communication with a flow control network in a hydraulic cylinder boss for controlling a direction and flow magnitude of hydraulic fluid within the hydraulic fluid chamber region, and an electric motor for driving the hydraulic pump system.

In general, certain embodiments of the present disclosure provide an electro-hydrostatic actuator comprising a piston assembly and a hydraulic cylinder. The piston assembly, having a piston head and a piston rod extending from the piston head, is located and movable within the hydraulic cylinder. The hydraulic cylinder includes a hydraulic fluid chamber region including a piston side chamber and a rod side chamber, a reservoir for storing hydraulic fluid located within the hydraulic cylinder which is in fluid communication with the hydraulic fluid chamber region. The electro-hydrostatic actuator includes a hydraulic pump system for moving hydraulic fluid in the reservoir and the hydraulic fluid chamber region, the hydraulic pump system in fluid communication with a flow control network in a hydraulic cylinder boss for controlling a direction and flow magnitude of hydraulic fluid within the hydraulic fluid chamber region, and an electric motor for driving the hydraulic pump system.

There is provided a control module for a hydraulic system. The module comprises a tank and a plurality of valves. The tank is configured to store hydraulic fluid and is substantially cylindrical. The plurality of valves fluidly connect with the tank and are configured to control distribution of hydraulic fluid from the tank to one or more components of the system. The plurality of valves are spaced around a circumference of the tank. One or more passages fluidly connect the tank with at least one of the plurality of valves and/or a first of the plurality of valves with a second of the plurality of valves.