Snecma

Snecma Moteurs

Safran Aircraft Engines

Edouard Joseph Jadczak

Valerio Gerez

Wouter Balk

Julien Christian Pascal Griffaton

Florian Poinsot-Berthelot

Cedric Magret

David Flores

Bruno Carratt

Pierrick Ollivier

Arnaud Fabrice Quenardel

Florian Poinsot-Berthelott

Valério Gerez

A gas turbine engine including: a casing in which is mounted at least one shaft for driving a fan solidly connected to a driving drum including blades to compress an airflow moving from upstream to downstream in the engine; and an axial retention mechanism, on standby, solidly connected to the casing and arranged to come into contact with the driving drum such as to prevent axial movement of the drum in event of breakage of the driving shaft.

Gas turbine engine comprising means for axially retaining a fan of the engine

A method of monitoring twisting vibration of a rotary shaft of a turbine engine includes obtaining a vibratory acceleration signal from a sensor located on a stationary component of the turbine engine. This vibratory signal is characterized by a carrier frequency. The method also includes evaluating a frequency spectrum of the vibratory signal and searching for a pair of spectral lines of amplitudes greater than at least a first threshold. The lines are distributed in the spectrum on either side of the carrier frequency of the vibratory signal, and spaced apart therefrom by a twisting frequency of the shaft. Where appropriate, the method includes issuing a warning message.

Method and device for monitoring torsional vibrations of a rotary shaft of a turbine engine

A method of monitoring vibratory phenomena that occur in an aviation gas turbine engine in operation includes establishing a frequency spectrum of a vibratory signal representative of the operating state of the engine and of its components; using a plurality of vibratory signatures, each corresponding to a vibratory phenomenon that occurs during operation of aeroengines of the same type as the engine being monitored and originating from a defect in or an abnormal operation of a component of the engines; identifying, in the spectrum, the points of curves that match mathematical functions, each defining a vibratory signature; and for each identified curve corresponding to a defect of engine components, analyzing the amplitude associated with the points of the curve relative to predefined amplitude values corresponding to a degree of severity of the defect; and as a result of an amplitude value being exceeded or an abnormal operation being detected, issuing a message associated with the vibratory signature.

Method and a system for monitoring vibratory phenomena that occur in an aviation gas turbine engine in operation

A decoupling system for a rotary shaft of an aircraft turbojet, the decoupling system including: a rolling bearing including rolling elements inserted between a first ring fastened to a stationary bearing support and a second ring mounted in a mounting chamber fastened to a rotary shaft; a transmission mechanism transmitting rotary torque from the rotary shaft to the second ring; a mechanism allowing the second ring to move radially relative to the mounting chamber when a static force associated with an unbalance affecting the rotary shaft exceeds a predetermined threshold; and a plurality of leaktight flexible bags interposed between the second ring and the mounting chamber and each including a heterogeneous structure including a porous capillary solid matrix and an associated liquid relative to which the matrix is lyophobic.

Uncoupling system for an aircraft turbojet engine rotary shaft

The present invention relates to a bearing support for a rotating engine such as a gas turbine engine, with a rotating shaft supported by at least one bearing and a frame, capable of running at least two different running speeds, characterised in that it comprises at least two mechanical supporting structures with different stiffnesses combined so as to support the bearing at one of these stiffnesses. The invention has the advantage that the use of mechanical structures avoids the presence of any hydraulic equipment, since the stiffness forces thus introduced can directly oppose excitation forces generated by the unbalanced mass of the engine shaft.

Bearing support with double stiffener

A shaft mounted to rotate with respect to another fixed or rotary element of a rotary engine to which the shaft is connected by at least one bearing, it being possible for the engine to operate in at least two different operating speeds, the shaft comprising a connection to the bearing that has a state of stiffness that varies with engine operating speed. The connection comprises a squirrel cage comprising at least two points of attachment, one to the bearing and one to the shaft, between which points there extends a flexible portion, the shaft comprises an actuator able to adopt at least two positions for controlling the state of stiffness of the squirrel cage, the actuator comprises a piston designed to be displaced by oil pressure in a chamber formed between the piston and shaft from a rigid state of stiffness position to a soft state of stiffness position.

Rotary engine with shaft bearing having two stiffnesses, rotary engine shaft and means of connection between a rotary engine shaft and a bearing

An aircraft turbojet including a fan having a hub driven by a shaft carried by at least one bearing connected to the structure of the turbojet by a bearing support that includes an interposed decoupling device. The hub carries at its periphery a plurality of blades that move inside a retention casing with radial clearance E between the tips of the blades and an inside wall of the retention casing. The inside wall is lined in a layer of abradable material suitable for being planed away by the tips of the rotating blades. The tips of the blades are suitable for being disintegrated by the inside wall of the retention casing in the event of an impact following the appearance of unbalance that has led to the bearing being decoupled, to obtain a clearance J&#x3e;E as required for operation of the decoupler.

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Le Mee sur Seine, France

Edouard Joseph Jadczak