Abstract: In an assembly with two concentric shafts, the internal shaft projecting beyond the external shaft, a seal support sleeve placed between the shafts has a conical shape and bears on a spacer mounted on the external shaft between an assembly nut of the forward end of the external shaft and a bearing, so that the nut is accessible to be unscrewed through the space between the two shafts, thus enabling the external shaft to be disassembled. The invention may be applicable to front bearings of gas turbine high pressure shafts and makes it possible to disassemble the high pressure body from the rear, without needing to disassemble equipment, such as a fan on the front of the machine, or hindering the installation of a gear.

Abstract: A multi-agent method and system for moving a virtual dummy in a virtual environment, the dummy being defined by an overall position and by a plurality of degrees of freedom for joints. The method includes a contribution from an attraction agent acting on the plurality of degrees of freedom of the joints of the dummy to move the dummy towards the target; and a contribution from an avoider agent acting on the overall position of the dummy as a function of parameters defining the environment in order to avoid collisions between the dummy and said environment. The method further includes a contribution from an ergonomy agent acting on the plurality of degrees of freedom of the joints of the dummy in order to correct the posture of the dummy automatically while it is moving towards the target.

Abstract: The invention relates to a method of manufacturing a hollow blade for turbine engine comprising a foot and a rotor blade, the method comprising a production stage of two external parts (14) as well as an assembling stage via diffusion bonding of these two external parts so as to obtain a blade preform.

Abstract: The invention relates to a composite target in the form of a bar made of ceramic powders and designed to be evaporated under an electron beam, the target comprising zirconia and at least one zirconia stabilizer. In characteristic manner, said target is wherein said zirconia stabilizer is at a molar content lying in the range 2% to 30% and wherein said zirconia is formed by more than 90% of a monoclinic phase. The invention is applicable to fabricating a ceramic thermal barrier of low thermal conductivity and high thermomechanical strength formed by evaporation under an electron beam.

Abstract: An annular turbine engine combustion chamber configured so that in an axial half-section, values of first acute angles formed between a line that is effectively the median of the half-section located between an external axial wall and an internal axial wall, and the principal directions, in this half-section, of the holes in an external portion of a chamber base, decrease as a function of the distance between the holes and this line that is effectively the median. Further, values of second acute angles formed between the line that is effectively the median and the principal directions, in this half-section, of the holes in an internal portion of the chamber base, decrease as a function of the distance between the holes and this line that is effectively the median.

Abstract: The invention pertains to an engine mount onto an aircraft structure comprising at least one connection means between a first and a second element such as an engine case and said structure, characterized by the fact that said connection means comprises an eccentric member housed in a bore of the first element, being rotational about a first axis, the eccentric member comprising a trunnion attached to the second element and of axis off-centred with respect to the first axis of rotation, the eccentric member being rotational about said off-centred axis. The solution of the invention has the advantage of allowing a compact assembly.

Abstract: A hollow blade is shaped by superplastic inflation of a blank made up of welded-together sheets. A die comprising two hollow shapes clamping the outline of the blank is placed inside an autoclave-forming enclosure in order to subject the blank to superplastic inflation, and the two hollow shapes are united by U-shaped clamps made of a material having a coefficient of thermal expansion that is smaller than that of the material constituting said shapes.

Abstract: An attachment device for attaching a blade to a turbine rotor disk in a turbomachine, the blade root forming a male portion engaged and held radially in a cavity of complementary shape in the rotor disk, with means for preventing the blade root from moving axially in the cavity, the blade axis being inclined relative to a perpendicular to the axis of rotation of the rotor, in a direction and at an angle that are designed to compensate at least in part for the displacement of the axis of the blade caused by the mechanical and thermal stresses applied to the rotor during operation of the turbomachine.

Abstract: A turbo-jet engine including a fixed structure and a fan rotor mounted on a drive shaft supported by a first bearing and a second bearing. The engine further comprises an axial retaining device configured to form an emergency bearing and to cooperate with the fixed structure and mounted rigidly to the drive shaft. The engine includes a structural flange on which the second bearing is fixed, and the axial retaining device comprises a retaining disk mounted on the drive shaft and configured to cooperate with a stop disk of the flange to axially retain the fan and form an emergency bearing.

Abstract: The turbojet includes a fixed structure, a fan rotor fixed to a drive shaft supported by a first bearing and a second bearing. The second bearing is mounted on the fixed structure through a bearing support part. The first bearing is mounted on the fixed structure of the turbojet through a device enabling it to be decoupled from the fixed structure. The second bearing is mounted on the bearing support part through a link acting as a ball joint. The turbojet also allows axial displacements of the second bearing with respect to the fixed structure of the turbojet if the first bearing should be decoupled. The centering function of the second bearing after decoupling of the first bearing is thus provided without introducing excessive stresses in the bearing.

Abstract: A tension decoupler includes first frangible rupture members, arranged in parallel to each other, and second structural rupture members, arranged in parallel to each other and parallel to the first rupture members. The frangible rupture members and the structural rupture members are designed to break only when the load applied to the decoupler device reaches or exceeds a predetermined load value, and the structural rupture members are designed to have sufficient fatigue strength as long as the applied load does not reach the predetermined load value.

Abstract: A method of manufacture of a multilayer ceramic shell mould out of a master pattern includes the steps of dipping the master pattern in a first slip containing ceramic particles and a binder, depositing sand particles to form a contact layer, dipping the master pattern in a second slip containing ceramic particles and a binder, depositing sand particles to form an intermediate layer, dipping the master pattern in at least a third slip containing ceramic particles to form a reinforcing layer. The ceramic particles of the slips includes mullite, alumina, or a mixture of the two, whereas no layer contains any zircon.

Abstract: The metal sheet of the invention includes means for fixing it to a support and a seal gasket laid out along these means. The fixing means comprise at least one lumen provided on the metal sheet by punching, with a cavity for receiving a head of a fixing component corresponding to a metal sheet portion protruding on the opposite face and a washer for transferring stresses between the metal sheet and the support on said protruding portion.

Abstract: A device for tuning clearance at rotor blade tips in a gas turbine rotor, the device comprising at least one annular air flow duct that is mounted around the circumference of an annular casing of a stator of the turbine, the annular air flow duct being designed to discharge air onto the casing in order to modify the temperature thereof. A tubular air manifold is disposed around the air flow duct(s). There are also disposed an air feed tube to supply the tubular air manifold with air and an air pipe opening in the tubular air manifold and opening out into the air flow duct(s). The air pipe is provided with a balancing diaphragm for balancing the air flowing through the pipe.

Abstract: An installation for non-destructive inspection makes use simultaneously of sensors responsive to different physical characteristics. In an example, a sensor support, e.g. a kind of carriage having running wheels via which it comes into contact with the surface to be inspected, is fitted with two types of sensor, namely an eddy current sensor and at least one ultrasound sensor.

Abstract: The invention relates to aerodynamically matching the rear fan of a turbojet having two fans and a low-pressure compressor at the front of the intermediate casing, said fans being driven by two independent shafts. Said compressor is disposed between the blades of the two fans and includes at least one ring of rotor blades around the periphery of a wheel driven by the drive shaft for the front fan, and at least two grids of stator vanes disposed on either side of the ring of rotor blades and inside a grid carrier ring. A stationary outer grid and a stator of variable pitch connect the ring to the fan casing.

Abstract: The invention relates to a ventilation system for a convergent divergent exhaust nozzle in a bypass turbojet comprising an afterburn chamber surrounded by an annular passage through which circulates a stream of cooling air, a convergent divergent axisymmetric nozzle arranged downstream of said afterburn chamber, each circle of flaps comprising alternately a plurality of controlled flaps, and a plurality of follower flaps, a circle of cold flaps arranged radially outside said nozzle and hinged at their upstream end to a conical shell linked to the downstream part of the casing.

Abstract: This invention refers to a labyrinth seal for a gas turbine engine incorporating from upstream to downstream ends, a high pressure compressor with a rotor, a diffuser and a fixed wall element forming at least one part of the internal envelope of the combustion chamber said seal comprising a stator part mounted on the wall element by virtue of an attaching part with flanges and supporting an annular wearing part said wearing part working jointly with a rotor element provided with at least one circumferential tooth integral with rotor of the compressor to form the labyrinth seal. It is characterized by the fact that at least one of the flanges of said attaching means is heavy enough to harmonize the rate of dilatation of the stator part with respect to the dilatation rate of the rotor element during engine accelerations. In conformity with another characteristic, ventilation orifices are arranged in the wall element.

Abstract: A device for tuning clearance at rotor blade tips in a gas turbine rotor, the device comprising at least one annular air flow duct that is mounted around the circumference of an annular casing of a stator of the turbine, the annular air flow duct being designed to discharge air onto the casing in order to modify the temperature thereof. A tubular air manifold is disposed around the air flow duct(s). There are also disposed an air feed tube to supply the tubular air manifold with air and an air pipe opening in the tubular air manifold and opening out into the air flow duct(s). The air pipe is provided with a balancing diaphragm for balancing the air flowing through the pipe.

Abstract: The distributor sectors (25) of a turbomachine are secured adjacent to a casing (31) with sealing sectors (32) alternating with them in the axial direction. The distributor sectors (25) are provided with force resistant faces (37; 39) through which forces exerted on the distributor sectors are transmitted to the casing. The inner surface of the casing (31) is smoother and is not fitted with any hooks; consequently, this casing (31) is less complicated to make and is less mechanically stressed to retain the 10 distributor sectors, and the distributor sectors may be installed by a purely axial movement.