Abstract: A turbine stator casing comprising a jacket and fastener hooks for fastening a turbine distributor nozzle, the hooks projecting from the inside face of the jacket, said jacket being made of a first alloy by hot isostatic compression using metal powder, said fastener hooks being made out of a second alloy that is more refractory than the first, and being secured to said jacket by diffusion welding during the hot isostatic compression. The casing also comprises inserts passing through the fastener hooks and through said jacket. These inserts, which are likewise secured to the jacket by diffusion welding, serve during manufacture of the casing to fasten the hooks to a mold portion inside which the jacket is formed. The invention is applicable to the turbines of airplane turbojets.

Abstract: An injection system for a turbomachine combustion chamber, the system comprising a fuel injection nozzle for vaporizing fuel in the combustion chamber and a mixer/deflector assembly coaxial with the injection nozzle and serving to mix fuel and oxidizer and to diffuse the mixture in the combustion chamber, said mixer/deflector assembly comprising a primary swirler and a secondary swirler disposed at a determined distance apart from each other in the axial direction and separated by a Venturi device disposed coaxially with the injection nozzle, the primary swirler being fixed securely to the injection nozzle and being spaced apart therefrom by a constant radial distance which is determined in such a manner that the fuel vaporized by the injection nozzle can under no circumstances impact on the primary swirler. The Venturi device preferably has an inside surface that presents an upstream portion with a slope discontinuity P.

Abstract: A method of assembling sectored elements of an annular stator of a high-pressure turbine of a turbomachine about a longitudinal axis of said turbine, in which method an angular distribution pattern is defined for distributing elements of the stator over a predetermined angular sector, said pattern being defined so as to prevent inter-sector zones of stator elements being in radial alignment, said zones being defined between two adjacent sectors of the same stator element, and so as to repeat said distribution pattern around the entire circumference of the stator.

Abstract: The invention relates to a fastener system for fastening together at least two parts, one of which includes at least one flange that is caused to bear against a surface of the other part by means of a plurality of pins each presenting a collar having a non-circular outline, said collar being received in a groove formed in a bearing surface of one of said parts, and being designed to prevent said pins from turning by abutment against a wall, wherein the outline of each collar includes two substantially opposite plane surfaces that serve as mutual abutments against two adjacent collars.

Abstract: A turbomachine comprising at least a first rotary assembly with a first shaft, a stator, and bearings secured to the stator and suitable for supporting the first shaft, one of said bearings being capable of giving way when an unbalance occurs in the first rotary assembly. The turbomachine further comprising brake means for braking the first shaft when the unbalance occurs, and bond means acting at the end of braking to bond a portion of the first shaft to a surrounding portion of the turbomachine. The turbomachine is intended to be used mainly in the field of aviation, and more particularly as an airplane turbojet.

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 machine stator and assembly and disassembly methods. The elements of a casing portion are formed of consecutive shells in line with grooves configured to house roots of guide vane stages that are fixed in place by springs and pins for stopping rotation. The elements are arranged in a complete circle, and the assembly is made by axially separating the elements to insert the guide vane stages between the elements by a radial movement.

Abstract: The invention proposes a method for passivating the contact surface of a refractory container made of mullite. Such a method is remarkable in that it comprises the following operations: a. application to the contact surface of a coating comprising 50% to 70% by weight of alumina flour (Al2O3) filler and 30% to 50% of binder, this binder itself comprising 50% to 60% of aluminum chloride AlCl3 dissolved in 40% to 50% of water; b. drying; c. firing of the container in an oxidizing atmosphere between 1450° C. and 1550° C. for at least 20 min. Application to the casting of titanium alloys.

Abstract: An annular combustion chamber for a turbomachine comprises inner and outer annular walls united by a transverse wall, the inner and outer walls are extended at their downstream ends by inner and outer fastener flanges for fastening respectively to inner and outer shells of a turbomachine casing in order to hold the combustion chamber in position, the inner flange being provided with a plurality of holes for feeding cooling air to a high pressure turbine of the turbomachine, the air feed holes through the inner flange being distributed circumferentially over at least two rows disposed in a staggered configuration.

Abstract: A device for balancing a rotating part, in particular a turbine rotor in a turbomachine such as a turbojet or the like, the device comprising at least one balance weight comprising engagement means for engaging it on an annular flange of the part, and locking means associated with the balance weight and with the annular flange to prevent the balance weight from moving relative to the annular flange and to block itself against moving both in rotation and in axial translation relative to the balance weight.

Abstract: The invention relates to a protection mask used during treatment of surfaces of turbomachine blades including a sand blasting step and/or a metal coating step. The mask is designed to resist surface treatment effects and to be placed on the surface to be protected, and forms a removable and reusable tool according to the invention. The use of such a tool improves the quality and productivity of treatment operations.

Abstract: The invention relates to a ceramic-based bushing for mounting in a turbomachine casing to provide a smooth bearing for a pivot of a variable-pitch vane. The bushing is constituted by a metal jacket and a ceramic ring secured to the inside wall of said jacket by brazing. The invention also provides a turbomachine compressor having variable-pitch stator vanes with pivots mounted in the casing by means of such bushings.

Abstract: A recentering device for a rotor shaft for recentering a rotor shaft relative to an axis X of a stator structure in the event of decoupling caused by excessive imbalance. The shaft, in normal operating conditions, lies on the axis X and is radially supported by a bearing support disposed in a bore of the axis X in the stator structure. The bearing support has an outside diameter smaller than the diameter of the bore, to enable the bearing support to orbit about the axis X in the event of decoupling. The bearing support is connected to the stator structure by radially fusible elements. The recentering device recenters the bearing support after decoupling.

Abstract: The device of the invention for supplying cooling air to a flap of an exhaust nozzle in a gas turbine, comprises a tube connecting the flap to a cooling air source. The tube comprises at least one telescopic portion and one ball-joint connection.

Abstract: A variable cycle propulsion system for a supersonic airplane, the system comprising at least one engine having means for producing exhaust gas and a gas exhaust nozzle for generating thrust for supersonic flight speeds, and at least one separate auxiliary propulsion assembly dissociated from said engine, having no gas generator, and capable of generating thrust for takeoff, landing, and subsonic flight speeds. The system further comprises gas flow tapping means movable between a position in which they tap off at least a fraction of the exhaust gas produced by said engine and feed it to said propulsion assembly to enable it to generate thrust for takeoff, landing, and subsonic cruising flight, and a position in which the gas produced by the engine is directed solely to the engine nozzle for supersonic cruising flight.

Abstract: A method of measuring the adhesion of a coating to a substrate, wherein the measurement is done in air and wherein an ultrasound transducer is applied to the substrate by means of a thin film of gel, and a quality factor is calculated, given by the ratio between the amplitudes of the echoes associated with the first two reflections on the substrate/coating interface after passing through the substrate or on the coating/air interface after passing through the substrate and the coating.

Abstract: The invention relates to a device for passive control of the thermal expansion of the extension casing of a turbo-jet engine, said extension casing surrounding the casing of the high pressure compressor of the turbo-jet engine, and including a flange for attachment to an upstream flange of the casing of the combustion chamber. It is characterised in that at least one circumferential cavity is provided between both said flanges wherein circulates a gas flux tapped at the inlet of the combustion chamber. One uses thus a natural circulation generated by the differential pressure. Thanks to the device of the invention, the flange is passively controlled, and the stresses resulting from a differential expansion between the skin of the casing and its attachment flange are reduced.

Abstract: Apparatus for searching for and detecting defects on parts that are substantially inaccessible, being located behind a wall, the apparatus comprising a first endoscope for illumination in visible light and for observation, the first endoscope and pipes for feeding and spraying penetration test substances being housed together in a rod which can be passed through an orifice in the wall in order to examine a part, the apparatus further comprising a second endoscope independent of the first endoscope and the rod for illuminating in ultraviolet light and for observing the portion of the part that has been treated by the penetration test substances.

Abstract: The invention relates to a turbojet having a low-pressure compressor and two fans at the front of an intermediate casing which fans are driven by two independent shafts. Said compressor is disposed under the rear fan and has a downstream ring of rotor blades connecting the rear fan to the drive shaft of the rear fan, an upstream rotor blade ring that is connected to the drive shaft of the front fan and at least one ring of stator blades that is disposed between the rings of rotor blades and inside an outer stator that is supported by a second intermediate casing. Bearings are interposed respectively between the two intermediate casings and the two shafts.

Abstract: A porous substrate having a concave inside face and an outside face is disposed in an enclosure, and reactive gas is introduced into the enclosure to densify the substrate. At least a portion of the gas is divided into two non-zero fractions. The first fraction of the gas is fed to the inside face of the substrate. The second fraction of the gas is fed to only the outside face of the substrate. Alternatively, the first fraction of the gas is fed via a tooling extending into an inside volume defined by the concave inside face of the substrate.