Abstract: The invention is a method of treating the surface of a steel mechanical part by the successive steps of subjecting the part to finishing to lower its surface roughness; cleaning; subjecting the cleaned part to a tribo finishing step to lower surface roughness and increase wettability; and subjecting the part to ambient temperature high speed projection of tungsten disulfide platelet particles to form a dense, self-lubricating deposit on the part.

Abstract: The present invention relates to a method of fabricating a rod of composite material from a fiber preform comprising a certain number of primary fiber plies connected together by links allowing plies to slide relative to one another while the preform is being shaped, the preform including a central portion for constituting the body of the rod and including two opposite side portions, together with extensions for forming lugs of the rod, which method includes the step of shaping the fiber preform so as to give it a hollow shape while keeping the two opposite side portions spaced apart so as to give the fiber preform an open profile in its central portion, followed by injecting resin and causing it to polymerize.

Abstract: The invention relates to a method of controlling a yawing movement of an aircraft running along the ground, the aircraft comprising at least one first landing gear with a steerable bottom part bearing wheels. According to the invention, the method comprises the steps of: on the basis of a yaw rate setpoint {dot over (?)}c, determining a wheel-steering prepositioning angle ?p; using closed-loop control which as its input has the yaw rate setpoint and which generates a command to steer the bottom part in order to steer it through a steering angle ?c equal to the sum of this prepositioning angle ?p and of an angle ?z which is determined taking account of an error between the yaw rate setpoint {dot over (?)}c and the measured yaw rate {dot over (?)}m when the steerable bottom part is steered by the steering angle ?c.

Abstract: The invention relates to a method of fabricating a connecting rod, the method including: fabricating a body (1) of metallic material reinforced by long fibers (5) oriented mainly along a longitudinal axis (X) of the body; fabricating an endpiece out of a metallic material reinforced by short fibers; and welding the endpiece to the end of the body using a friction-mixing welding technique.

Abstract: The invention relates to a controlled-friction device comprising first and second elements (1, 2) mounted to move relative to each other in a sliding direction, the device of the invention being characterized in that it includes first and second friction members (5, 5) arranged symmetrically between the two elements in order to rub selectively against the second element, each of the friction members being urged towards a wedging position by a presser member (6), the first friction member being arranged, in a first direction of relative movement between the two elements along the travel direction, to tend to prevent relative movement between the two elements, and in a second direction to exert on the two elements an opposing friction force that depends on a stress applied against the first wedge member by the presser member; while the second friction member is arranged in the second direction to tend to prevent relative movement of the two elements, and in the first direction to exert on the two elements an op

Abstract: The invention relates to a mechanical transmission device for transmitting a threshold force, the device comprising a first element (1; 101) and a second element (2; 102) rotatably mounted relative to each other about an axis of rotation (X), and having a transmitter member (10; 110) interposed between them to constrain the two elements to rotate together when a torque is imparted to one of the elements for transmitting the torque to the other one of the elements, up to a threshold torque beyond which the two elements become movable in rotation against an opposing torque equal to the threshold torque, the transmitter member comprising: at least a first friction disk (11; 111) constrained to rotate with the first element, and a second friction disk (12; 112) facing the first disk; a bearing member (13; 113) that is axially movable to press the disks together and against a bearing turntable (15; 115) of the first element under drive from a presser member; and rotary drive means (20, 21; 120, 121) interposed

Abstract: A controlled-friction device comprising a first element having a second element mounted thereon to slide in a sliding direction, and friction retaining means arranged to exert between the two elements an opposing force against relative movement of the two elements. The friction retaining means comprises a friction member mounted securely to the first element to rub against the second element via a friction surface extending parallel to the sliding direction, a presser member for exerting a thrust force on the friction member, urging the friction member against the second element in a direction normal to the relative movement of the elements, and a link means linking the friction member to the first element causing the friction member to separate from the second element during movement in either direction of the second element relative to the first element.

Abstract: The invention relates to an aircraft having wheels fitted with hydraulically-actuating friction brake means and also hydraulically-actuated independent drive means for driving the wheels in rotation and enabling the aircraft to move in stages of independent drive in which the engines of the aircraft are inactive, wherein the aircraft is fitted simultaneously with a main hydraulic circuit including a pressure source that powers the brake means when said pressure source is active; with an alternative braking circuit for enabling brake means to be actuated at least when the engines of the aircraft are stopped, the alternative braking circuit including an accumulator that is normally used for parking braking and that is kept under pressure by the pressure source of the main circuit when said pressure source is active; and with an auxiliary hydraulic circuit pressurized by auxiliary pump means activated by an auxiliary power unit of the aircraft to enable the independent drive means to be actuated; the auxiliary h

Abstract: The invention relates to an independent drive device for an aircraft, the drive device comprising a motor member, drive means for driving an aircraft wheel in rotation, which means are adapted to co-operate with said wheel to drive it in rotation, and coupling means interposed between the motor member and the drive means to selectively couple the wheel to the motor member, the coupling means comprising two coupling members of complementary shape, comprising a first coupling member constrained to rotate with the drive means and a second coupling member constrained to rotate with the motor member. The independent drive device includes measurement means for generating information representative of a relative speed of rotation of the second coupling member relative to the first coupling member, the device being associated with motor control means adapted to cause the motor to rotate so as to cancel the relative speed of rotation between the coupling members prior to coupling them together.

Abstract: The invention relates to a hydraulic valve comprising a body in which a bore is formed in order to receive a sleeve that includes sealing seats that cooperate with a wall of the bore to define hydraulically isolated chambers that are connected to hydraulic ports in the body, the sleeve including connection holes in order to connect at least certain chambers with the inside of the sleeve and receiving a movable element that is slidable between two end positions in order to slide in leaktight manner against an inside wall of the sleeve, wherein the sleeve includes at least one regulator hole that opens out inside the sleeve in such a manner as to be the first bore to be uncovered or the last bore to be blocked by one of the fitted portions of the movable element when said element slides from one position to another, said fitted portion having at least one face portion that presents a setback that passes over the regulator hole.

Abstract: The invention relates to a management method for managing a turning movement of an aircraft taxiing on the ground, the aircraft having wheels each fitted with an independent drive device, in which method commands are generated for the independent drive devices so that at least some of those devices contribute to the turning movement. According to the invention, the method comprises the steps of: estimating at each instant during the turning movement: an instantaneous total power developed by all of the independent drive devices in response to the commands; and an instantaneous mean angular acceleration for all of the wheels; and adapting the commands to the independent drive devices such that the total instantaneous power developed by all of the independent drive devices is minimized, while conserving the mean angular acceleration.

Abstract: A method of managing a ground connection of an aircraft having landing gear with wheels that are subjected to static loads, some of which wheels are fitted with respective braking devices and others are fitted with respective independent drive devices, the method including the step of causing a modification to a distribution of the static loading to which the wheels of the landing gear are subjected in such a manner as to: increase the loading on at least some wheels fitted with respective braking devices, during a braking stage; and increase the loading on at least some wheels fitted with respective independent drive devices, during an independent drive stage.

Abstract: The invention provides airplane landing gear comprising at least one axle for carrying at least one brake-and-wheel assembly comprising a rim mounted to rotate on the axle and a stack of disks and a support carrying modular electromechanical actuators that are individually removable, the landing gear and the brake-and-wheel assembly being organized in such a manner that each actuator is in at least one of the following configurations: an empty space of dimensions sufficient for receiving the actuator extends on a disassembly path directly facing the actuator when it is in an operating position; the actuator is associated with displacement means enabling it to be moved from an operating position to a disassembly position, an empty space of dimensions sufficient to receive the actuator extending along a disassembly path directly facing the actuator when it is in the disassembly position.

Abstract: The invention relates to a method of controlling an electromechanical brake for a vehicle wheel, the brake including an actuator provided with a pusher that is actuated by an electric motor and that is adapted to exert a braking force selectively on friction elements in response to an actuation setpoint, the method comprising the following steps: from a braking setpoint ( F), determining a nominal position setpoint ( X) for the brake actuator; from said braking setpoint ( F), estimating a reference current (i*) that ought normally to be flowing in the motor of the actuator to apply a force equal to the braking setpoint; comparing the reference current (i*) with a current (i) actually flowing in the motor of the actuator, and deducing a position correction (xcorr); and adding the position correction to the nominal position setpoint.

Abstract: The invention relates to an architecture for a hydraulic system for operating the landing gear of an aircraft including at least one pressure source and at least one hydraulic return, the system having a hydraulic circuit comprising a first hydraulic line that, when pressurized, causes the landing gear to be lowered, and a second hydraulic line that, when pressurized, causes the landing gear to be raised, said lines being selectively pressurized by means of a hydraulic distribution member comprising at least an isolation valve and a selector for putting one of the lines into communication with pressure and the other line into communication with return.

Abstract: A device for selectively connecting a tire to a pneumatic unit of an aircraft, the tire forming part of a wheel mounted to rotate on a hollow axle of the aircraft, the device comprising a stator and a rotor that is mounted to rotate relative to the stator and that includes means enabling it to be rotated by the wheel. The stator is bell-shaped and is designed to be received as a push-fit in the axle, and includes an end wall carrying a first pneumatic port for connection to the pneumatic unit via a tube running along the inside of the axle, the rotor extending substantially inside the stator.

Abstract: A device for selectively connecting a tire to a pneumatic unit of an aircraft, the tire forming part of a wheel mounted to rotate on a hollow axle of the aircraft, the device comprising a stator and a rotor that is mounted to rotate relative to the stator and that includes means enabling it to be rotated by the wheel. The stator is bell-shaped and is designed to be received as a push-fit in the axle, and includes an end wall carrying a first pneumatic port for connection to the pneumatic unit via a tube running along the inside of the axle, the rotor extending substantially inside the stator.

Abstract: A hydraulic braking architecture for aircraft comprising a plurality of wheels fitted with brakes, each including two half-cavities, the architecture comprising: a first braking circuit including servovalves, each powering one or more half-cavities on separate brakes; and a second braking circuit including servovalves, each powering one or more half-cavities on separate brakes; both hydraulic circuits operating simultaneously in such a manner that on each brake, one of the half-cavities is powered by a servovalve of the first braking circuit, and the other half-cavity is powered by a servovalve of the second braking circuit, at least one of the half-cavities being powered by a servovalve that powers only said half-cavity.

Abstract: The invention relates to an actuator including an electrical machine. The electrical actuator (100) comprising: a polyphase machine (101); at least one connection member (143) for powering the actuator from at least one network (146) delivering alternating current; and first and second buses (106, 107) connected in parallel between each connection member (143) and the machine (101) for applying frequency control thereto. Each inverter (111, 131) comprises a plurality of arms each having two controlled switches, each phase of the machine (101) being connected both to the two switches of an arm of the first inverter (111) and also to the two switches of an arm of the second inverter (131). The actuator further comprises controlled connection and disconnection means interposed between each bus (106, 107) and each connection member. The invention is applicable to actuators used in aviation.

Abstract: The invention relates to a method of managing the braking of an aircraft while taxiing on an airport, the method comprising, on the basis of characteristics for a sequence of movements of the aircraft along at least one given path to be followed by the aircraft on the airport, the step of deducing information concerning the braking to be performed so that the aircraft does indeed travel in application of said sequence of movements.