Abstract: 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.

Abstract: The invention relates to a method and a system for monitoring vibratory phenomena that occur in an aviation gas turbine engine in operation.

Abstract: 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.

Abstract: 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>E as required for operation of the decoupler.

Abstract: The rotary engine of the invention comprises at least a shaft, mounted to rotate with respect to another element of the engine, fixed or rotary, to which it 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 means of connection to the bearing that have a state of stiffness that can vary with the engine operating speed.

Abstract: 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>E as required for operation of the decoupler.