Transient unbalance simulation device and turbomachine equipped with such a device

Abstract

A transient unbalance simulation device (10) configured to simulate a transient unbalance in a turbomachine (100) at a predetermined speed, the transient unbalance simulation device (10) comprising a fixing portion (12), a flyweight (14) and a connector (16) mechanically connecting the fixing portion (12) and the flyweight (14), an assembly (E) formed by the connector (16) and the flyweight (14) being configured to adopt a first configuration when the speed of the turbomachine (100) is lower than a predetermined speed, and to adopt a second configuration distinct from the first configuration, when the speed of the turbomachine (100) is greater than or equal to the predetermined speed, in which in the first configuration the flyweight (14) is arranged at a first position (P1) and in the second configuration the flyweight (14) is arranged at a second position (P2) distinct from the first position (P1).Figure for abstract: Fig. 4.

Description

Title of the invention: Transient unbalance simulation device and turbomachine equipped with such a device Technical field

[0001] The present disclosure relates to a transient unbalance simulation device and a turbomachine equipped with such a device.

[0002] The term "turbomachine" refers to all gas turbine devices producing motive power, among which we distinguish in particular turbojets providing the thrust necessary for propulsion by reaction to the high-speed ejection of gas, and turboshafts in which the motive power is provided by the rotation of a drive shaft. For example, turboshafts are used as engines for helicopters, ships, trains, or even as industrial engines. Turboprops (turboshafts driving a propeller) are also turboshafts used as aircraft engines. Prior art

[0003] Under certain flight conditions of an aircraft equipped with a propulsion turbomachine, a transient imbalance may be created within the turbomachine, for example when a bird is ingested or when the conditions are right for ice to form at the inlet of the turbomachine (so-called "icing" conditions). In the latter case, the ice formed may detach in blocks from a rotor, the residual ice attached to the rotor then generating an imbalance (a phenomenon known as "ice release").

[0004] In order to test and size turbomachines for this type of event, it is important to be able to simulate a transient unbalance on a test bench. Known devices of the "imposed unbalance" type where a flyweight is simply fixed eccentrically within the turbomachine, of the "impulse excitation" or "ping test" type where the impulse response of the equipment at a standstill is studied, or of the "actuator" type allowing a flyweight to be physically moved within a turbomachine in operation, are either not sufficiently representative of the phenomenon studied, or too heavy and complex to implement.

[0005] Other systems relating to an unbalance phenomenon are known from FR3125087, FR2943726 and FR2943725, but these systems are for turbomachines in operation, are not for experimental purposes and are unrelated to the context of this presentation.

[0006] There is therefore a need for a simple and effective experimental device for simulating transient unbalance within a turbomachine in operation. Presentation of the invention

[0007] One embodiment relates to a transient unbalance simulation device configured to simulate transient unbalance in a turbomachine at a predetermined speed, the transient unbalance simulation device comprising a fixing portion configured to be fixed to a rotating element of the turbomachine, a flyweight and a connection mechanically connecting the fixing portion and the flyweight, an assembly formed by the connection and the flyweight being configured to adopt a first configuration when the speed of the turbomachine is lower than a predetermined speed, and to adopt a second configuration distinct from the first configuration, when the speed of the turbomachine is greater than or equal to the predetermined speed,wherein in the first configuration the weight is arranged in a first position relative to the fixing portion and in the second configuration the weight is arranged in a second position relative to the fixing portion, distinct from the first position.

[0008] In the following, and unless otherwise indicated, by “the device” is meant “the transient unbalance simulation device”.

[0009] In use, the attachment portion may be attached to a rotor of the turbomachine, for example, a rotating shaft, a rotating bladed wheel, or any other rotating element of the turbomachine. For example, in the first configuration, the device may be configured to be balanced and not generate any imbalance within the turbomachine when the speed of the turbomachine is lower than the predetermined speed (i.e. in the first configuration).

[0010] The weight is mechanically connected to the fixing portion via the connection. The connection may have a certain rigidity to maintain the weight in the first position as long as the speed of the turbomachine, that is to say the rotational speed of a rotating part of the turbomachine, for example the rotational speed of the fan, or of the shaft of the low pressure body or of the shaft of the high pressure body, is lower than the predetermined speed. For example, the connection may be configured to have no elastic deformation, or negligible elastic deformation, as long as the speed of the turbomachine is lower than the predetermined speed.For example, the predetermined speed may be between 1000 rpm (one thousand revolutions per minute) and 30000 rpm (thirty thousand revolutions per minute), for example between 1000 rpm (one thousand revolutions per minute) and 10000 rpm (ten thousand revolutions per minute) for a device configured to simulate a transient unbalance within a low pressure rotor, for example between 10000 rpm (ten thousand revolutions per minute) and 30000 rpm (thirty thousand revolutions per minute) for a device configured to simulate a transient unbalance within a high pressure rotor.

[0011] The assembly comprising the flyweight and the connection (hereinafter and unless otherwise indicated “the assembly”) is configured so that, when the speed of the turbomachine becomes greater than or equal to the predetermined speed, the flyweight moves from the first position to the second position. For example, the assembly may be configured to move from the second configuration to the first configuration, and therefore for the flyweight to move from the second position to the first position, when the turbomachine speed becomes lower than the predetermined speed, but not necessarily.

[0012] For example, the connection and / or the weight may have a sacrificial portion or one configured to break and allow the weight to pass from the first position to the second position when the speed of the turbomachine becomes greater than or equal to the predetermined speed. For example, the connection may comprise a sacrificial screw holding the weight in the first position within a guide or a rail, the screw being breakable, for example by shear stress, from a force threshold reached when the speed of the turbomachine becomes greater than or equal to the predetermined speed, the weight then being guided by the rail to the second position (for example reached when the weight cooperates in abutment against an ad hoc stop).According to another example, the connection and / or the weight may have a ratchet (or a ratchet system) configured to allow the weight to move from the first position to the second position when the speed of the turbomachine becomes greater than or equal to the predetermined speed. According to yet another example, the connection and / or the weight may be configured to deform elastically (i.e. in the elastic regime of the materials) or plastically (i.e. in the plastic regime of the materials) and allow the weight to move from the first position to the second position when the speed of the turbomachine becomes greater than or equal to the predetermined speed.

[0013] The first position and the second position may be two discrete and distinct positions, and the transition from one to the other may be brief or instantaneous. In other words, the transition from the first position to the second position, and possibly vice versa, may not be progressive over time, or may not be proportional to the rotational speed of the rotor. In other words, the flyweight does not have any equilibrium position between the first and second positions. The transition from the first position to the second position characterizes the “transient” aspect of the unbalance: in the first position there is no unbalance (or negligible for the test concerned) while in the second position there is a predetermined unbalance, the transition from the first to the second position being instantaneous when the speed of the turbomachine becomes greater than or equal to the predetermined speed.

[0014] For example, the second position may be only radially offset, for example radially outward, relative to the first position. For example, the second position may be radially spaced from the first position by a distance of between 5 mm (five millimeters) and 500 mm (five hundred millimeters). For example, the mass of the flyweight may be between 1 g (one gram) and 500 g (five hundred grams). For example, the device may be configured so that the transient unbalance is between 100 cm.g (one hundred centimeter grams) and 30,000 cm.g (thirty thousand centimeter grams). For example, the connection may be metallic, for example made of steel or titanium, or any alloy based on steel and / or titanium, for a rotor upstream of a combustion chamber, or made of nickel or inconel or any alloy based on nickel or inconel for a rotor downstream of a combustion chamber.

[0015] As a reminder, generally within a turbomachine the axial direction corresponds to the direction of the axis of rotation of a shaft of the gas generator, and a radial direction is a direction perpendicular to the axis of rotation. The azimuthal or circumferential direction corresponds to the direction describing a ring around the axial direction. The three axial, radial and azimuthal directions correspond respectively to the directions defined by the coast, the radius and the angle in a cylindrical coordinate system.

[0016] By allowing the weight to move from the first position to the second position when the speed of the turbomachine becomes greater than or equal to the predetermined speed, the device simulates the instantaneous generation of an unbalance of a predetermined mass (i.e. the mass of the weight), at a predetermined position (the second position), from the predetermined speed. The device therefore allows perfect control of the experimental parameters for generating an unbalance, while having a simple structure that is easy to install within the turbomachine (via the fixing portion). In other words, the device makes it possible to change a predetermined unbalance as quickly as possible so as to reproduce a transient phenomenon during an accidental event, for example during the ingestion of a bird or the release of ice.This type of event is distinct from a case of maintained and stabilized unbalance which can notably appear if the rotor is poorly balanced or if an element is damaged or worn.

[0017] In some embodiments, the attachment portion may comprise a ring. Alternatively, the attachment portion may comprise only a ring.

[0018] Such a fixing portion can ensure a certain balance in the first configuration, a certain ease and reliability of mounting on a rotating element of the turbomachine, and a simplicity of structure facilitating the manufacture of the device. Such a fixing portion can participate in controlling the experimental parameters for generating an imbalance, while providing the device with a simple structure that is easy to install within the turbomachine.

[0019] In some embodiments, the first position of the weight may be re- dially closer to a center of the ring than the second position of the weight, the first position and the second position being radially inside the ring.

[0020] Such an arrangement of the first and second positions relative to the ring can contribute to controlling the experimental parameters for generating an imbalance, while providing the device with a simple structure that is easy to install within the turbomachine. This can, for example, also allow easy assembly / disassembly of the device, which can lead to reducing the time of use of the test bench, compared to the assembly / disassembly time of a more complex device of the state of the art, or even to avoiding the use of explosives requiring the presence of a pyrotechnician, to artificially generate an imbalance on a test bench.

[0021] In some embodiments, the connector may comprise a beam. Alternatively, the connector may comprise only a beam.

[0022] By "beam" is meant any element having a great length in relation to the dimensions of its transverse section (i.e. transverse to the length direction), for example a length at least ten times greater than the maximum extent of the transverse section (for example an extent in a width or height direction, or a diameter, etc.). The transverse section can have any shape.

[0023] For example, the beam has a first end and a second end opposite the first end, the first end being mechanically connected to the attachment portion while the second end is mechanically connected to the weight. For example, the beam extends radially. For example, the attachment portion comprises a ring, the beam extends radially from the ring to the inside of the ring, and the weight is disposed radially inside the ring.

[0024] Such a beam can participate in controlling the experimental parameters to generate an unbalance, while providing the device with a simple structure that is easy to install within the turbomachine.

[0025] In some embodiments, the unbalance simulation device may be configured so that the beam deforms by buckling when the speed of the turbomachine is greater than or equal to the predetermined speed.

[0026] For example, the buckling may be elastic buckling so that the assembly can return to the first configuration when the speed of the turbomachine becomes lower than the predetermined speed.

[0027] The beam can maintain the flyweight in the first position as long as the speed of the turbomachine is lower than the predetermined speed, and when the speed of the turbomachine becomes higher than or equal to the predetermined speed, the beam buckles under the effect of the centrifugal force exerted by the flyweight which exceeds a predetermined threshold. determined and instantly brings the weight from the first position to the second position. When the turbomachine speed falls below the predetermined speed, the centrifugal force exerted by the weight on the beam falls below the predetermined threshold, so that the beam instantly straightens and brings the weight from the second position to the first position. The buckling phenomenon being very rapid, instantaneous, the device can produce an unbalance in the shortest possible time to simulate an accidental transient such as a bird ingestion or an ice release.

[0028] For example, the beam may have in the first configuration an imposed shape suitable for ensuring controlled deformation of the beam when the weight moves from the first position to the second position, and ensuring that buckling occurs on the desired side.

[0029] Such a buckling-deformable beam can contribute to controlling the experimental parameters for generating an imbalance, while providing the device with a particularly simple structure that is easy to install within the turbomachine. The device can be reusable, which can make it particularly economical.

[0030] In some embodiments, the transient unbalance simulation device may include a guide configured to guide the weight in translation between the first position and the second position.

[0031] For example, the guide may extend radially and may be configured to guide the weight radially, for example only radially. Such a guide may be implemented with various solutions, such as for example the sacrificial part, the ratchet system or the beam configured to deform by buckling mentioned above.

[0032] Such a guide can improve the control of the passage of the weight between the first and second positions, as well as the maintenance of the weight in these two positions. In other words, the guide can make it possible to control the trajectory of the weight between the first and second positions. The guide can participate in controlling the experimental parameters to generate an unbalance, while providing the device with a simple structure that is easy to install within the turbomachine.

[0033] In certain embodiments, the weight may have a spherical shape or a cylindrical shape of circular section.

[0034] For example, the cylinder of circular section may have an axis extending perpendicular to the radial direction, for example perpendicular to the length direction of the beam, and for example parallel to the plane of the ring of the fixing portion.

[0035] Such shapes may for example allow rotational movements of the weight, for example in relation to the possible guide, whereby the buckling of the beam can remain free and unrestrained. In other words, such forms of the weight can ensure that the degrees of freedom necessary to allow the beam to buckle remain free (i.e. not blocked).

[0036] In some embodiments, the attachment portion may be configured to be attached to a flange for attachment of a turbojet fan cone.

[0037] This can allow particularly easy, reliable and rapid mounting of the device within a turbomachine such as a turbojet, the fan cone being a portion directly accessible from the outside of the turbojet and easily removable to access the flange on which the cone is mounted.

[0038] One embodiment relates to a turbomachine comprising a transient unbalance simulation device according to any one of the embodiments described in the present disclosure. Brief description of the drawings

[0039] The object of the present disclosure and its advantages will be better understood upon reading the detailed description given below of different embodiments given as non-limiting examples. This description refers to the appended pages of figures, in which:

[0040] [Fig-1] [Fig.l] partially represents a turbomachine equipped with a device transient unbalance simulation,

[0041] [Fig.2] [Fig.2] represents a perspective view of the transient unbalance simulation device,

[0042] [Fig.3] [Fig.3] represents a cutaway view of the turbomachine of [Fig.l], when the speed of the turbomachine is lower than a predetermined speed,

[0043] [Fig.4] [Fig.4] represents a cutaway view of the turbomachine of [Fig.l], when the speed of the turbomachine is greater than or equal to the predetermined speed,

[0044] [Fig.5] [Fig.5] represents a variant of the transient unbalance simulation device, and

[0045] [Fig.6] [Fig.6] represents a variant of mounting a transient unbalance simulation device within a turbomachine. Description of the embodiments

[0046] [Fig.l] represents a partial view of a turbomachine 100, in this example a turbojet, equipped with a transient unbalance simulation device 10. The turbomachine 100 comprises in this example a fan 52 and a gas generator 54. In this example, the gas generator 54 comprises from upstream to downstream, the gases flowing within the turbomachine 100 from upstream to downstream, a compressor (or compressor section), a combustion chamber, and a turbine (or turbine section). For the purpose of simplification and readability of [Fig.l], only a part of the com presser, in this example a part of the low pressure compressor 54CBP, is shown, the other elements of the gas generator not being shown and well known elsewhere. The nacelle 80 of the turbomachine 100 is shown schematically, the turbomachine 100 being for example mounted on a test bench not shown. In this example, the transient unbalance simulation device 10 is mounted, upstream of the combustion chamber, for example upstream of the gas generator 54. [Fig.6] represents a variant where the transient unbalance simulation device 10 is mounted within a turbine 102 of a turbomachine, for example a low pressure turbine, downstream of the combustion chamber.

[0047] [Fig. 2] shows in more detail the transient unbalance simulation device 10. The device 10 is configured to simulate a transient unbalance in a turbomachine at a predetermined speed. The transient unbalance simulation device 10 comprises a fixing portion 12 configured to be fixed to a rotating element of the turbomachine 100, a flyweight 14 and a connector 16 mechanically connecting the fixing portion 12 and the flyweight 14. An assembly E formed by the connector 16 and the flyweight 14 is configured to adopt a first configuration (see FIGS. 2 and 3) when the speed of the turbomachine 100 is lower than a predetermined speed, and to adopt a second configuration (see [Fig. 4]) distinct from the first configuration, when the speed of the turbomachine 100 is greater than or equal to the predetermined speed.In the first configuration, the weight 14 is arranged at a first position PI relative to the fixing portion 12 and in the second configuration, the weight 14 is arranged at a second position P2 relative to the fixing portion 12, distinct from the first position PL.

[0048] In this example, the fixing portion may comprise a ring 12 of axis X. The ring 12 may have a plurality of through holes 12A, for example for the passage of fixing bolts 90A or 190A (see [Fig. 1] or [Fig. 6]). The ring 12 may have a radial width LR that varies along the circumferential direction C, to ensure the balance of the device 10 so that it does not generate any imbalance when the assembly E is in the first configuration and the speed of the turbomachine is lower than the predetermined speed. According to a variant not shown, the ring 12 may have a constant radial width LR along the circumferential direction C, and be equipped with a balancing counterweight.

[0049] In this example, the connection may comprise a beam 16 extending along a length direction L (the length Lo of the beam being measured along the length direction L). The beam 16 may extend radially inside the ring 12, so that the length direction L is parallel to the radial direction R of the ring 12. The beam 16 may have a tongue shape. For example, the tongue may have a rectangular cross-section to the length direction L. beam 16 has a first end 16A and a second end 16B opposite the first end 16A along the length direction L, the first end 16A being mechanically connected to the ring 12 while the second end 16B is mechanically connected to the flyweight 14. The flyweight 14 can be arranged radially inside the ring 12. As will be described in more detail below, the device 10 is configured so that the beam 16 deforms by buckling when the speed of the turbomachine 100 is greater than or equal to the predetermined speed.

[0050] For example, the ring may have a maximum radial width LR1, or be equipped with a counterweight not shown, at a position diametrically opposite the connection 16.

[0051] For example, the fixing portion 12 and the connector 16 may form a single piece, for example resulting from the cutting of a sheet metal, for example a metal sheet. For example, the fixing portion may comprise only the ring 12 and the connector may comprise only the beam 16.

[0052] The weight 14 may have a spherical shape (variant not shown) or as in the present example, a cylindrical shape with a circular section. In this example, the cylindrical shape of the flyweight 14 has an axis B, perpendicular to the radial direction R and parallel to the plane of the ring 12. In this example, the axis B is inscribed in a plane P containing the neutral fiber (not shown) of the beam 16. With reference to FIGS. 3 and 4, the first position PI of the flyweight 14 is radially closer to the center A of the ring 12 than the second position P2 of the flyweight 14, the first and second positions PI and P2 being radially inside the ring 12. According to an example not shown, the position PI may correspond to a position centered on the axis of the turbomachine 100 when the device 10 is mounted on the turbomachine 100. For example, the position PI may correspond to the center of the ring 12.For example, to determine the position of the weight 14, we can consider the position of the center of gravity of the weight 14. In the example of figures 2, 3 and 4, the position PI is eccentric relative to the center A of the ring 12.

[0053] In the present example, the device 10 may comprise a guide 18 configured to guide the weight 14 in translation between the first position P1 and the second position P2. In this example, the guide 18 is a radial guide, which radially guides the weight 14 between the positions P1 and P2. In this example, the guide 18 may restrict any movements of the weight in translation along the axial direction X and in rotation around the radial direction R. The connection 16 may for example have sufficient rigidity to block any movements of the weight 14 in translation along the circumferential direction C and in rotation around the axial direction X. In this example, the guide 18 and the weight 14 may be configured to allow rotational movements of the weight around a direction perpendicular to the radial direction R and parallel to the plane of the ring 12, in this example around the direction of the axis B of the weight 14. In this example, the guide 18 may comprise four rods 18A extending within the ring 12 between parallel to the length direction L of the beam 16, and framing two by two in the axial direction X the weight 14. For example, the weight 14 has two free end portions 14A and 14B opposite in the direction of the axis B of the weight 14, each end 14A and 14B being sandwiched in the axial direction X by a pair of rods 18A. The cylindrical shape of the weight 14 can allow the latter to rotate around its axis B within the guide 18, and allow bending of the beam 16 leading to its buckling and a purely radial translational movement of the weight 14.As shown in [Fig.2], when the device 10 is not in use, the assembly E is in the first configuration and the weight in the first position PI.

[0054] In this example, for mounting the device 10 within a turbomachine, the fixing portion 12 is configured to be fixed to a flange 90 for fixing a turbojet fan cone 92 (see [Fig.l]). In this example, the ring shape of the fixing portion 12 and the holes 12B allow the device 10 to be fixed to the flange 90 of the turbomachine 100 for fixing the cone 92 of the fan 52. In this example, when the device 10 is mounted within the turbomachine 10, the axial X, radial R and circumferential C directions of the device 10 and of the turbomachine 100 are merged, so that the axial, radial and circumferential directions of the device 10 correspond respectively to the axial, radial and circumferential directions of the turbomachine 100. The fixing portion 12 can be configured to be fixed between two successive disks 192 and 194 of turbine wheels (see [Fig.6]).

[0055] In use, when the turbomachine 100 operates at a speed lower than the predetermined speed, in this example when the fan 52 rotates at a speed lower than the predetermined speed, the assembly E remains in the first configuration, as shown in [Fig. 3]. The flyweight 14 is in the first position PI, and no unbalance is generated. When the turbomachine 100 operates at a speed greater than or equal to the predetermined speed, in this example when the fan 52 rotates at a speed greater than or equal to the predetermined speed, the centrifugal force exerted by the flyweight 14 on the beam 16 becomes such that the beam 16 is deformed by buckling, in this example by elastic buckling, and the assembly E instantly passes from the first configuration shown in [Fig. 3] to the second configuration shown in [Fig. 4].The weight 14 then instantly moves from the first position PI to the second position P2, and a predefined unbalance, . the mass of the flyweight and the position P2 being predefined, is generated instantly. All measurements can then be carried out and all relevant parameters of the turbomachine 100 recorded under these experimental unbalance simulation conditions. In this example, the buckling of the beam 16 being elastic, when the speed of the turbomachine 100 becomes lower than the predetermined speed (in this example when the fan 52 turns again at a speed lower than the predetermined speed) the centrifugal force exerted by the flyweight 14 on the beam 16 decreases and becomes such that the beam 16 straightens, the assembly E returning to the first configuration and the flyweight 14 returning from the second position P2 to the first position PI. The device 10 can then be reused for other tests, within the same turbomachine or on another turbomachine.

[0056] Generally speaking, the experimental parameters for simulating the unbalance, and in particular the predetermined regime, can for example be determined by the dimensioning of the beam and the weight. For example, the beam can be dimensioned to buckle when it is subjected to a force greater than or equal to a force F = M (Ro - Lo) O2 , where the force F is expressed in Newton (N), M is the mass of the weight 14 expressed in kilograms (Kg), Ro is the internal radius of the ring 12 at the point of junction with the beam 16 expressed in meters (m), Lo is the length of the beam 16 expressed in meters (m), and Q is the regime or speed of rotation to which the device 10 is subjected expressed in radians per second (rad / s), the characteristics of the beam 16 being able to be obtained via the Euler formula p = n2 EI / (0.7.Lo)2, where the force F is expressed in Newton (N), E is the Young's modulus expressed in Pascal (Pa), I is the quadratic moment of beam 16 expressed in meters to the power of four (m4) and Lo is the length of beam 16 expressed in meters (m). Note that the coefficient 0.7 is specific to this example, and linked to the presence of the guide 18. According to a variant without guide 18, the coefficient 0.7 would be replaced by 2.0.

[0057] [Fig. 5] represents a transient unbalance simulation device 110 according to a variant of the device 10 where the connection / beam 16 is replaced by a connection / rod 116 extending radially and having two notches 116A, 116B configured to receive the weight 14 and hold it in position in two different positions. The other elements are unchanged compared to the device 10, retain the same reference signs and are not described again. The notch 116A, closest to the axis X in the radial direction R, is configured to hold the weight 14 in the first position P1 while the notch 116B, furthest from the axis X in the radial direction R, is configured to hold the weight 14 in the second position P2. Between the two notches 116A and 116B, the rod 116 forms a track configured to radially guide the weight 14 between the first position PI and the second position P2. When the speed of the turbomachine is lower than a predetermined speed, the flyweight 14 remains within the notch 116A, in the first position PL When the speed of the turbomachine is greater than or equal to the predetermined speed, under the effect of the centrifugal force exerted by the flyweight 14, the rod 116 deforms elastically so that the flyweight 14 disengages from the notch 116A, slides radially outward along the track until it engages in the second notch 116B, in the second position P2. The rod 116 and the notches 116A and 116B form an example of a ratchet system configured to allow the flyweight 14 to move from the first position PI to the second position P2 when the speed of the turbomachine becomes greater than or equal to the predetermined speed. Just like the device 10, the device 110 can be mounted upstream of the gas generator (see [Fig. 1]) or within a turbine (see [Fig. 6]).

[0058] Although the present invention has been described with reference to specific embodiments, it is obvious that modifications and changes may be made to these examples without departing from the general scope of the invention as defined by the claims. In particular, individual features of the various illustrated / mentioned embodiments may be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than restrictive sense.

[0059] It is also obvious that all the characteristics described with reference to a method are transposable, alone or in combination, to a device, and conversely, all the characteristics described with reference to a device are transposable, alone or in combination, to a method.

Claims

Claims

1. Transient unbalance simulation device (10, 110) configured to simulate a transient unbalance in a turbomachine (100) at a predetermined speed, the transient unbalance simulation device (10, 110) comprising a fixing portion (12) configured to be fixed to a rotating element (52) of the turbomachine (100), a flyweight (14) and a connector (16, 116) mechanically connecting the fixing portion (12) and the flyweight (14), an assembly (E) formed by the connector (16, 116) and the flyweight (14) being configured to adopt a first configuration when the speed of the turbomachine (100) is lower than a predetermined speed, and to adopt a second configuration distinct from the first configuration, when the speed of the turbomachine (100) is greater than or equal to the predetermined speed,in which in the first configuration the weight (14) is arranged in a first position (PI) relative to the fixing portion (12) and in the second configuration the weight (14) is arranged in a second position (P2) relative to the fixing portion (12), distinct from the first position (PD-,

2. A transient unbalance simulation device (10, 110) according to claim 1, wherein the fixing portion comprises a ring (12).

3. A transient unbalance simulation device (10, 110) according to claim 2, wherein the first position (PI) of the weight (14) is radially closer to a center (A) of the ring (12) than the second position (P2) of the weight (14), the first position (PI) and the second position (P2) being radially inside the ring (12).

4. A transient unbalance simulation device (10) according to any one of claims 1 to 3, wherein the connection comprises a beam (16).

5. Transient unbalance simulation device (10) according to claim 4, configured so that the beam (16) deforms by buckling when the speed of the turbomachine (100) is greater than or equal to the predetermined speed.

6. Transient unbalance simulation device (10, 110) according to any one of claims 1 to 5, comprising a guide (18) configured to guide the weight (14) in translation between the first position (PI) and the second position (P2).

7. A transient unbalance simulation device (10, 110) according to any one of claims 1 to 6, wherein the weight (14) has a spherical shape or a cylindrical shape of circular section.

8. A transient unbalance simulation device (10, 110) according to any one of claims 1 to 7, wherein the attachment portion (12) is configured to be attached to a flange (90) for attaching a turbojet fan cone (92).

9. Turbomachine (100) comprising a transient unbalance simulation device (10, 110) according to any one of claims 1 to 8.

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