Abstract: A toothed coupling mechanism for an assembly of rotating elements of an aircraft gas turbine engine includes a pair of coupling halves having an axial toothed coupling interface therebetween. Each coupling half has a plurality of splined teeth inter-engaged about an axis for transmitting torque therebetween. A protrusion is located on one of the splined teeth of one of the coupling halves. A splined tooth of the other coupling half comes into contact with the protrusion in a situation of uncoupling of said coupling halves.

Abstract: The invention relates to a system (12) for the recovery of energy from exhaust gases from at least one turboshaft engine, comprising a turbine (34) fitted rotatably around a recovery shaft (40), adapted to bleed off at least a part (14) of the exhaust gases, known as bleed gases (14), and to expand said bleed gases (14) to become expanded gases (42) at a pressure below atmospheric pressure, a first heat exchanger (44), adapted to use a cold source (45) to cool said expanded gases (42) to become cooled gases (46), and a compressor (36) fitted rotatably around said recovery shaft (40), adapted to compress said cooled gases (46) to atmospheric pressure.

Abstract: The invention relates to a mechanical fuse intended to be rigidly mounted between a drive unit (8, 9), and a receiver unit (10), each rotating about the same axis (7) of rotation, said fuse comprising a body (13) extending in a longitudinal direction parallel to said axis (7) of rotation, once the fuse is mounted between said drive unit (8, 9) and receiver unit (10). The invention is characterized in that said body (13) comprises a plurality of longitudinal bars (14), each bar (14) being deformable by bending, such as to form a twist-breakable mechanical fuse.

Abstract: The invention relates to an architecture of a propulsion system of a multiple-engine helicopter comprising turboshaft engines (5, 6), characterised in that it comprises: at least one hybrid turboshaft engine (5) that is capable of operating in at least one standby mode during a stable flight of the helicopter, the other turboshaft engines (6) operating alone during this stable flight; an air turbine (30) that is mechanically connected to the gas generator (17) of the hybrid turboshaft engine (5) and is suitable for rotating said gas generator (17); means for withdrawing pressurised air from the gas generator (27) of a running turboshaft engine (6); and a duct (31) for routing this withdrawn air to said air turbine (30).

Abstract: A method of notifying an authorization to shut down completely an aircraft gas turbine engine, the method being applied after detecting that the engine has passed to an idling speed, and including a) an evaluation step of using a value of a first operating parameter of the engine to evaluate a value for a second parameter T45MG wherein a thermal behavior of a part of the engine that might be subjected to coking; b) a comparison step (E30) of comparing the value of the second parameter T45MG with a predefined threshold value T45thresh corresponding to a value of the second parameter that does not lead to coking of the part; and c) a notification step of notifying authorization to shut down completely the engine if the value of the second parameter T45MG is lower than the value of the predefined threshold T45thresh, else reiterating steps a) to c).

Abstract: The invention relates to a system (12) for the recovery of energy from exhaust gases from at least one turboshaft engine, comprising a turbine (34) fitted rotatably around a recovery shaft (40), adapted to bleed off at least a part (14) of the exhaust gases, known as bleed gases (14), and to expand said bleed gases (14) to become expanded gases (42) at a pressure below atmospheric pressure, a first heat exchanger (44), adapted to use a cold source (45) to cool said expanded gases (42) to become cooled gases (46), and a compressor (36) fitted rotatably around said recovery shaft (40), adapted to compress said cooled gases (46) to atmospheric pressure.

Abstract: The invention relates to a mechanical fuse intended to be rigidly mounted between a drive unit (8, 9), and a receiver unit (10), each rotating about the same axis (7) of rotation, said fuse comprising a body (13) extending in a longitudinal direction parallel to said axis (7) of rotation, once the fuse is mounted between said drive unit (8, 9) and receiver unit (10). The invention is characterized in that said body (13) comprises a plurality of longitudinal bars (14), each bar (14) being deformable by bending, such as to form a twist-breakable mechanical fuse.

Abstract: A method of notifying an authorization to shut down completely an aircraft gas turbine engine, the method being applied after detecting that the engine has passed to an idling speed, and including a) an evaluation step of using a value of a first operating parameter of the engine to evaluate a value for a second parameter T45MG wherein a thermal behavior of a part of the engine that might be subjected to coking; b) a comparison step (E30) of comparing the value of the second parameter T45MG with a predefined threshold value T45thresh corresponding to a value of the second parameter that does not lead to coking of the part; and c) a notification step of notifying authorization to shut down completely the engine if the value of the second parameter T45MG is lower than the value of the predefined threshold T45thresh, else reiterating steps a) to c).

Abstract: The invention relates to an architecture of a propulsion system of a multiple-engine helicopter comprising turboshaft engines (5, 6), characterised in that it comprises: at least one hybrid turboshaft engine (5) that is capable of operating in at least one standby mode during a stable flight of the helicopter, the other turboshaft engines (6) operating alone during this stable flight; an air turbine (30) that is mechanically connected to the gas generator (17) of the hybrid turboshaft engine (5) and is suitable for rotating said gas generator (17); means for withdrawing pressurised air from the gas generator (27) of a running turboshaft engine (6); and a duct (31) for routing this withdrawn air to said air turbine (30).

Abstract: The invention relates to a fastener device (100) for fastening at least one sensor, in particular a thermocouple, to a part, the device comprising a first fastener portion (10) having fastener means (14) for fastening to the part and a second fastener portion provided with an orifice for receiving the sensor (90). According to the invention, the device further comprises an elastically deformable portion (20) connecting together the first and second fastener portions, and the elastically deformable portion (20) is configured in such a manner as to pass from a stable position to an unstable position when the first fastener portion (10) is fastened to a part, thereby pressing the second fastener portion against the part.

Abstract: A method and structure negating thermal inertia of a solid portion, such as shielding, which influences mechanical behavior of parts of an engine structure, by reducing forces transmitted to the engine structure during an event in which a turbine blade ruptures, while preserving mechanical strength and vibratory positioning. The structure includes a flexible fastener for a shield, enabling producing a fusible section. An assembly for mounting a shielding onto a casing of the engine structure of a turbine includes connection lugs and points for attachment to the casing and shielding. The attachment points are sufficiently spaced apart in accordance with curvature of the shielding and casing so connection between the lugs and the shielding or casing, and connection of the attachment points, are substantially tangential. The lugs are sized so the connection has sufficient flexibility to control vibratory positioning thereof and ensure sufficient mechanical strength under thermo-mechanical loads.

Abstract: A lubrication device including a bypass valve with an inlet connected to a feed circuit, a first outlet to be connected to elements to be lubricated, and a second outlet connected to a bypass circuit. The valve includes a valve member slidable between first and second positions, and separating a cavity into first and second chambers. The first chamber is connected to the inlet. In the first position, a fluid flow passage from the first chamber to the second chamber is open, and from the first chamber to the first outlet is closed. In the second position, a fluid flow passage from the first chamber to the first outlet is open, and from the first chamber to the second outlet is closed. At least in the second position, the valve member separates the chambers in substantially leaktight manner, while the second chamber remains in fluid flow communication with the second outlet.

Abstract: A mechanical protection device including: a transmission shaft having a main axis of rotation and an element that is frangible under a torsional overload; a movable member secured to the transmission shaft to rotate about the main axis and configured to move radially outwards relative to the main axis from a first position to a second position; a spring urging the movable member towards the first position; and a tangential abutment configured to stop rotation of the movable member about the main axis when the movable member is in the second position. The movable member and the spring are calibrated so that from a predetermined trigger angular speed the movable member moves from the first position to the second position under effect of centrifugal force greater than prestress of the spring.

Abstract: A device for filtering intake air of an internal combustion engine, including at least one filtering element including an inlet for air being treated, a first clean air outlet toward the engine, and a second air outlet toward the outside, and a ventilation mechanism driving the air from the second air outlet. The ventilation mechanism includes a fan wheel driven by a turbine set into motion by a gas flow taken from the engine.

Abstract: A mechanical protection device including: a transmission shaft having a main axis of rotation and an element that is frangible under a torsional overload; a movable member secured to the transmission shaft to rotate about the main axis and configured to move radially outwards relative to the main axis from a first position to a second position; a spring urging the movable member towards the first position; and a tangential abutment configured to stop rotation of the movable member about the main axis when the movable member is in the second position. The movable member and the spring are calibrated so that from a predetermined trigger angular speed the movable member moves from the first position to the second position under effect of centrifugal force greater than prestress of the spring.

Abstract: A lubrication device including a bypass valve with an inlet connected to a feed circuit, a first outlet to be connected to elements to be lubricated, and a second outlet connected to a bypass circuit. The valve includes a valve member slidable between first and second positions, and separating a cavity into first and second chambers. The first chamber is connected to the inlet. In the first position, a fluid flow passage from the first chamber to the second chamber is open, and from the first chamber to the first outlet is closed. In the second position, a fluid flow passage from the first chamber to the first outlet is open, and from the first chamber to the second outlet is closed. At least in the second position, the valve member separates the chambers in substantially leaktight manner, while the second chamber remains in fluid flow communication with the second outlet.

Abstract: A method and structure negating thermal inertia of a solid portion, such as shielding, which influences mechanical behavior of parts of an engine structure, by reducing forces transmitted to the engine structure during an event in which a turbine blade ruptures, while preserving mechanical strength and vibratory positioning. The structure includes a flexible fastener for a shield, enabling producing a fusible section. An assembly for mounting a shielding onto a casing of the engine structure of a turbine includes connection lugs and points for attachment to the casing and shielding. The attachment points are sufficiently spaced apart in accordance with curvature of the shielding and casing so connection between the lugs and the shielding or casing, and connection of the attachment points, are substantially tangential. The lugs are sized so the connection has sufficient flexibility to control vibratory positioning thereof and ensure sufficient mechanical strength under thermo-mechanical loads.

Abstract: A device for filtering intake air of an internal combustion engine, including at least one filtering element including an inlet for air being treated, a first clean air outlet toward the engine, and a second air outlet toward the outside, and a ventilation mechanism driving the air from the second air outlet. The ventilation mechanism includes a fan wheel driven by a turbine set into motion by a gas flow taken from the engine.