Societe Nationale D'etude Et De Construction De Moteurs D'aviation

Snecma Moteurs

Other

Hispano Suiza

Daniel Germain Kettler

Jean-Pierre Ruis

Philippe Pierre Bouiller

Pierre-Yves Bourquin

Michel Franchet

Fabrice Michel Cot

Jacky S Naudet

Michel Andre Bouru

Jean-Marie Brocard

Marion Michau

Michel M Lechevalier

Didier Georges Feder

Henry Roger Leclerc

Andre Dhainaut

Guy d'Agostino

Jean-Marie N Pincemin

Alain Lavie

Guy Jean-Louis Lapergue

Yves R Berneuil

Xavier J Pasquali

Bertrand Pierre Renaud Monville

Laurent Claude Patrick Salperwyck

Pascal Lejeune

Christian W Bettremieux

The actuator assembly comprises a master actuator and at least one slave actuator having a cylinder containing a piston defining two chambers in the cylinder. A first chamber of the slave actuator is connected to an outlet of a directional control valve which is connected to a hydraulic control circuit and to a control member whose position determines the pressure in the first chamber of the slave actuator. A displacement of the piston of the master actuator is transferred to the control member of the control valve associated with the slave actuator by means of a mechanical transmission such as a flexible linear rolling bearing. Thus, the displacement of the piston of the slave actuator is servo-controlled to the displacement of the piston of the master actuator by controlling the position of the control member of the control valve associated with the slave actuator. The actuator assembly is suitable for use in particular for controlling the moving flaps of the nozzle of a turbojet of variable exhaust section, and possibly also steerable.

Actuator assembly with synchronized hydraulic actuators

An electrohydraulic actuator comprising: a hydraulic actuator comprising a piston secured to a member to be controlled and capable of moving in a cylinder under drive from a hydraulic fluid; a hydraulic pump feeding both faces of the piston with hydraulic fluid via channels integrated in the walls of the cylinder; an electric motor immersed in the hydraulic fluid, and controlled and powered electrically by an electronic control unit, driving the hydraulic pump in rotation; and a hydraulic accumulator for compensating variations in the volume of the hydraulic fluid; the hydraulic actuator, the hydraulic pump, the electric motor, and the hydraulic accumulator having a common axis of symmetry and being mounted in alignment in a common housing that is leaktight to the hydraulic fluid, thereby forming an axially symmetrical self-contained hydraulic assembly.

Electrohydraulic actuator

An electrohydraulic device for varying the pitch of the blades of a machine rotor, the blades being mounted on a hub rotated by a drive shaft of the machine, and each blade having a root capable of pivoting about a longitudinal axis of the blade, the drive shaft itself being rotated relative to a stationary structure of the machine, the device comprising firstly a hydraulic actuator whose piston is secured to a control and synchronization ring in which off-center wrist pins are engaged, each fixed in register with one of said blade roots, and having a cylinder closed by a cover that includes a high pressure hydraulic pump feeding hydraulic fluid to both faces of said piston via channels integrated in said cylinder of the actuator, and secondly an electric motor controlled and powered by an electricity generator comprising an inductor secured to said stationary structure of the machine and an armature secured to said drive shaft of the machine.

Electrohydraulic device for varying the pitch of the blades of a machine rotor

An axisymmetric, converging-diverging turbojet-engine exhaust nozzle for jet deflection. The diverging flaps are connected by linkrods to a vectoring ring ( ). The vectoring ring ( ) is driven by linear actuators ( ) anchored in the stationary structure ( ). The linear actuators ( ) are connected by a swivel ( ) to the vectoring ring ( ) and are affixed to the stationary structure ( ) to absorb the tangential loads applied by the exhaust gases on the diverging flaps and to allow positioning the vectoring ring ( ). Preferably the linear actuator ( ) is connected by a sheath ( ) to the vectoring ring ( ), the sheath ( ) slidable on the actuator case ( ) and being displaceable in a radial plane passing through the turbojet-engine's axis.

Axisymmetric, converging-diverging, jet-deflecting turbojet-engine exhaust-nozzle

An axially symmetric turbojet engine exhaust-nozzle includes a system for masking the exhaust jet, such system including inner hot flaps (,), hinging on a conical shell (,) and driven by a first control ring (,) powered by linear actuators (,), and outer cold flaps (,) hinging on an annular assembly (,) and driven by a second control ring (,) powered by linear actuators (,) to vary the angle of the cold flaps. The annular assembly (,) is axially displaceable by a third set of linear actuators (,). Each cold flap (,) comprises an inner skin (,) fitted with orifices (,) and hinging on the annular assembly(,) and an outer skin (,) spaced radially away of the inner skin (,) to define an air flow channel between the skins. When the annular assembly (,) is moved downstream by the third set of linear actuators (,), the outer skins (,) form a scoop introducing fresh air into the cold flaps (,), and said air is injected into the hot gas flow through the orifices (,) in the inner skin and other orifices (,) at the trailing edge (,) of the cold flaps to reduce the exhaust signature.

Turbo jet engine exhaust nozzle with masked gas jet

A gas-flow exhaust assembly for a jet propulsion system of an aircraft in which a converging exhaust nozzle (4) is fitted with translating cold flaps (21, 22). The primary exhaust nozzle (4) comprises two hot-flaps (5, 6) situated beyond a primary duct (1) enclosed by an aircraft fairing (2). The fairing (2) is extended by a secondary exhaust nozzle (20) which is supported by the primary duct (1) and which is translatable by a control mechanism (27a, 27b). The secondary exhaust nozzle (20) comprises cold flaps (21, 22) which are driven by another control mechanism (29a, 29b) independently of the angular positions of the hot flaps (5, 6). Preferably, there are two eyelid-shaped cold-flaps (21, 22) hinging and supported on horizontal transverse shafts (23a, 23b). The shafts (23a, 23b) are preferably affixed on two lateral slides (24a, 24b) which slide on the primary duct (1) and are displaceable by the control mechanism (27a, 27b) which translates the secondary exhaust nozzle (20).

Converging exhaust nozzle fitted with translating cold flaps

Two objects are articulated together by a strong and compact joint which provides two rotational degrees of freedom about axes X and Y, and which comprises a bearing have a male inner ring swivel mounted in a female outer ring. The male inner ring is rotatably mounted on a shaft integral with one of the objects and defining the axis X, and the female outer ring is attached to the other object. The two rings are rotationally linked in the direction of an axis Z perpendicular to the X and Y axes by two flat support surfaces on the inner ring arranged between two flat guide surfaces in the outer ring, the said support surfaces and the said guide surfaces being parallel to the X and Z axes.

Assembly of two objects articulated to each other with two degrees of

An actuating system for a variable area exhaust nozzle is disclosed having inner and outer flaps pivotally connected to an airframe whose positions may be varied by a single set of control cylinders. The control cylinders have a case in which is slidably mounted a pair of pistons, each having piston rods extending from one side, which piston rods extend through one end of the cylinder case. The piston rods may be arranged coaxially to minimize the bulk of the actuating cylinder. One of the piston rods is connected to the inner flaps, while the other of the piston rods is connected to the outer flaps. By selectively supplying pressurized fluid to one or more combinations of a first fluid chamber defined between one of the pistons and an end of the case, a second fluid chamber defined between the two pistons, and a third fluid chamber defined between the other of the pistons and the other end of the case the two piston rods can be made to extend or retract so as to move the inner and outer flaps to desired positions.

Actuating system for a variable area exhaust nozzle

A compound seal for affecting a seal on a translating shaft movable within a sleeve to separate high pressure and low pressure zones. The compound seal includes a sealing member and a clamping member disposed in a groove formed in one of the elements. The sealing member defines sealing sides which cooperate with one of the sides of the grooves and with the other of the elements. The clamping member cooperates with the bottom and the high pressure side of the groove, and with the sealing member so as to exert a force thereon extending substantially along the bisector of an angle defined by the sealing sides.

Compound seal with pressure equalization aperture

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Chartrettes, France

Daniel Germain Kettler