Abstract: The invention relates to the sealing of the cavity from which air is bled off to the cabin, which cavity is delimited, on the one hand, by the external shell of the compressor and an annular structure connected to the shell, and, on the other hand, by the external casing of the diffuser grating and a strut connected to said external casing and to an external engine casing shell fastened to the annular structure. A first seal is fitted in a first groove provided around the upstream part of the external casing of the diffuser grating, the strips of this first seal bearing on the downstream end of a first projection integral with the annular structure. A second seal is fitted in a second groove provided under said annular structure, the strips of this second seal bearing on the downstream end of a second projection integral with said annular structure and on the end of a third projection formed on the upstream part of the external casing of the diffuser.

Abstract: A rolling bearing defines a separation between an oil enclosure and an air enclosure. The bearing includes rolling elements defining a first side opening and a second side opening, and includes an annular junction piece having an annular contact surface with the structural piece. An oil film is disposed at the annular contact surface between the structural piece and the junction piece and is laterally defined by at least two sealing rings. A sealing device covers at least part of the first side opening. A first oil circulation device feeds the oil film with oil and feeds the rolling elements beside the oil enclosure with oil from the oil film. A second oil circulation device, independent of the first, recovers the oil used for lubricating the rolling elements and is arranged in such a manner as to avoid oil flowing towards the air enclosure.

Abstract: The system retains a plate against a disk presenting in its radial face an annular recess defined by a plurality of walls, one of which is formed by a face of a flange, said plate presenting an annular base pressing against the radially outer wall of the recess and a root which extends from the base into the recess, said system including a split annular retaining ring disposed in the recess. In characteristic manner, said flange presents a top end of crenellated outline provided with at least one notch, said root is provided with a front rim of crenellated outline, having at least one mortise, and a rear rim between which rims there is formed an annular groove for receiving the ring which presents an axial tenon suitable for penetrating into said notch and into said mortise.

Abstract: The pitch control mechanism (controlling the angular position) for stator blades in a turbojet may be adjusted separately for two adjacent stages of blades controlled by a common actuator 10. To achieve this, the synchronization bar 9 located between the mechanisms leading to the two stages is inclined, this inclination being determined by a pin 22 and groove 23 connection with the casing, while another pin 26 and groove 27 connection is arranged between the synchronization bar 9 and one of the mechanisms. Strongly non-linear displacement laws between the two mechanisms may thus be controlled depending on the shapes and directions of the grooves.

Abstract: In a moving turbine wheel, blade inserts are used with at least two blades interconnected by common outer and inner platforms and sharing a common root. The blade inserts have hollow roots in which respective recesses are formed, and the insert roots belonging to the same wheel and/or two different wheels are voluntarily given different configurations in order to adjust the resonant frequencies of the inserts to values that are significantly different, thereby ensuring that the inserts in the same wheel and/or between two different wheels are out of tune.

Abstract: The device for detection of an oil unbalanced mass inside the rotor of a machine includes a device configured to entrain oil present in the rotor in rotation, such that the oil rotation speed is practically the same as the rotation speed of said rotor.

Abstract: The present invention provides non-axially symmetrical manufactured parts of thickness less than 10 mm, made of ? or quasi-? titanium alloy, having a core microstructure constituted by whole grains presenting a slenderness ratio greater than 4 and an equivalent diameter lying in the range 10 ?m to 300 ?m. The invention also provides a method of manufacturing the parts by forging.

Abstract: The invention provides an electronic wrench which includes means for measuring the instantaneous applied torque and means for measuring the instantaneous angle of rotation during tightening. The physical parameters of the screw connection for tightening and a setpoint value for the tightening are initially entered into the wrench via a keypad. During the tightening operation, the processor means calculate the instantaneous traction force on the screw fastener as a function of the measured instantaneous values of torque and angle and as a function of the recorded characteristics of the screw fastener.

Abstract: A turbomachine including a high pressure compressor with a downstream cone, a diffuser extending downstream by an inner casing disposed radially outside the downstream compressor cone, a combustion chamber disposed radially outside the inner diffuser casing, and a high pressure turbine whose rotor is connected to the downstream cone of the compressor by a connection drum, the inner diffuser casing and the downstream compressor cone defining between them an under-chamber cavity that is situated downstream from a discharge labyrinth in which cooling air flows downstream, wherein the engine also includes a stator shroud that is installed under the inner diffuser casing downstream from the discharge labyrinth.

Abstract: The invention provides a device for holding strip sealing gaskets on a turbomachine nozzle, the nozzle being constituted by a plurality of sectors having guide vanes which extend between inner and outer platforms elements, at least one of said platform elements having a sealing strip (30) disposed radially in a space between said platform element and an adjacent structural element in order to provide fluid tightness between said elements, the corresponding strips of two adjacent sectors touching, and their joint being covered by a joint cover (31) disposed between said strips, and by a holding member for holding said strips in the sealing position.

Abstract: The invention provides a welding device (10) using a power laser beam (22), the device (10) being miniaturized, the device (10) being suitable for being moved very close to the surface (52a) of the part (52) to be welded and of reaching welding zones that are difficult to access, but without vapor and particles of molten metal (56) being capable of penetrating into the inside and dirtying the optical components (28, 48, 46). Such a device is remarkable in that it includes a feed (26) of gas under pressure suitable for producing a primary flow of gas (50) leaving via the front opening (20) together with the laser beam (22), and in that it also includes a nozzle (60) connectable to a source of gas under pressure, said nozzle (60) producing a secondary flow of gas (62) sweeping the front opening (20) transversely, thereby deflecting the primary flow of gas (50) laterally.

Abstract: A gas turbine blade of a turbomachine includes in its central portion a centrally-located first cooling circuit at least a suction side cavity, at least a pressure side cavity, at least a central cavity extending between the suction side cavity and the pressure side cavity, a first air admission opening at a radially bottom end of the suction side cavity, a second air admission opening at a radially bottom end of the pressure side cavity, at least a first passage putting a radially top end of the suction side cavity into communication with a radially top end of the central cavity, at least a second passage putting a radially top end of the pressure side cavity into communication with the radially top end of the central cavity, and outlet orifices opening out both into the central cavity and into the pressure side face of the blade.

Abstract: A method of reducing vibration in a structure comprising at least one rotor (101j) and a fixed set of sources of disturbance (102j) liable to give rise to disturbances in the fluid flow (11) that cause the rotor to vibrate, the method comprising a step of distributing the fixed sources of disturbance angularly in non-uniform manner so as to reduce the amplitude of excitation as seen by the rotor, and a step which consists in verifying that the maximum amplitude of a response of the rotor to the excitation is obtained by: determining a first signal whose Fourier transform corresponds to the frequency spectrum of the excitation in the event of the fixed sources of disturbance being distributed in a predetermined angular distribution; by modifying the first signal into a second signal adapted to said selected angular distribution for the fixed sources of disturbance; by determining the frequency spectrum of the excitation by calculating the Fourier transform of the second signal; and by calculating the respon

Abstract: The invention relates to a method of improving the retention capacity of a blade having an asymmetrical hammerhead connection and extending in a conical stream, with the root of the blade being retained in a peripheral groove in a disk, said groove having an upstream lip and a downstream lip presenting respective bearing surfaces that extend in planes that are asymmetrical relative to planes perpendicular to the axis of rotation of said disk, and against which the surfaces of the upstream and downstream flanks of said root come to bear, the bearing surface of said upstream lip being connected to the bottom wall of said groove via a rounded surface, and the upstream flank presenting, in the vicinity of said rounded surface, a heel situated inside a circle of radius R centered on the axis about which said blade tends to pivot when axial stress is applied thereto, said circle outlining, in the upstream lip, a crescent shape of thickness e, wherein: a) the connection between the bearing surface of the upstream

Abstract: The present invention pertains to an automated polishing process for semi-finished mechanical parts in titanium or titanium alloy, using a machine with abrasive belt mounted on a tangential contact wheel driven in rotation at a determined speed and applied at a determined pressure, the wheel travelling with respect to the part's surface at a determined rate, characterized by the fact that the abrasive belt consists of superabrasive grains in industrial diamond or cubic boron nitride. The process is applied to geometric conforming of jet engine fan or compressor blades.

Abstract: A turbine disk cooling device fed with cooling air from an orifice through an annular support platform for a fixed vane of a low-pressure turbine is disposed between an upstream flange and a downstream flange of the support platform. The device includes upstream and downstream annular plates longitudinally defining an annular cavity, a sealing device extending longitudinally between the upstream and downstream plates so as to close the cooling air cavity, an element to hold the upstream and downstream plates against upstream and downstream flanges of the support platform, and a plurality of holes for ejecting cooling air towards the turbine disks.

Abstract: A turbine engine mount to a pylon of an aircraft includes a bracket arranged to be attached to the pylon, and a lever attached in its central part to the bracket via a first connection and two thrust links each joined aft to the lever by a second connection. The lever includes a central part with two arms, and the bracket includes an integral attachment lug placed between the two arms and connected to the arms via a pivot pin to form the first connection. The lever is laterally connected to the bracket via pivot pins passing through the lever and mounted with a clearance to form connections on standby.

Abstract: A turbomachine blade includes a metal alloy airfoil having a cavity closed off by a cover on a hollowed side, the cover providing aerodynamic continuity of the hollowed side and being bonded via an edge thereof to the rest of the airfoil by a weld bead. The weld bead emerges on the hollowed side and penetrates into the airfoil to a depth P at least equal to the thickness EC of the edge of the cover so as to provide continuity of material between the edge of the cover and the rest of the airfoil over a depth at least equal to the thickness EC of the edge of the cover. A process for manufacturing such a blade is also disclosed.

Abstract: The invention relates to an annular combustion chamber for a turbomachine of axis X, in which the chamber end wall is fixed to inner and outer side walls by means of a plurality of radially-inner attachment fittings and by means of a plurality of radially-outer attachment fittings disposed upstream from said chamber end wall by bolting a zone of each of said fittings to said side walls. At least one of said pluralities of attachment fittings is integrated in a ring secured to the chamber end wall and comprises a plurality of pairs of tabs which extend upstream beyond the bolting zones, the two tabs in each pair being disposed circumferentially on either side of a bolting zone and being interconnected at their upstream end to the upstream end of a fixing plate which extends between said two tabs and which presents a bolting zone for being fixed to the adjacent side wall.

Abstract: A device for stopping rotation of a fixed blade bearing sector in a gas turbine casing. Sectors of synchronizing ring blades are maintained against tangential rotational movements by sliding into grooves of a casing by pins passing through perforations in an extension of the two parts. The pins are prevented from accidental removal either by a flexible lock ring or by a locking tab maintained between the two parts when they have been completely assembled.