Turbine engine turbine assembly

Abstract

The present invention relates to a turbine engine turbine assembly (10) having a longitudinal axis (X), the assembly comprising an exhaust cone (40) having an upstream portion (40a) and a downstream portion (40b), the upstream portion (40a) having an upstream internal annular wall (51) and an upstream external annular wall (50) radially surrounding the upstream internal annular wall (51), the downstream portion (40b) having a downstream external annular wall (52), wherein the upstream external annular wall (50) and the downstream external annular wall (52) are rigidly attached to the upstream internal annular wall (51) via a plurality of connecting members (60), the connecting members (60) being elastically deformable at least in an axial direction and in a radial direction, the connecting members (60) being circumferentially arranged, each connecting member (60) being rigidly attached to the upstream external annular wall (50), to the downstream external annular wall (52) and to the upstream internal annular wall (51).

Description

Description Title: Turbomachine turbine assembly Technical field

[0001] The present disclosure relates to a turbomachine turbine assembly, in particular to an ejector cone, in particular made partly of a ceramic matrix composite material, in such an assembly. It also relates to a turbine comprising such an assembly and to a turbomachine comprising such a turbine. Prior art

[0002] Conventionally, as shown in Figure 1, a turbomachine 10 of the double-flow turbojet type comprises, from upstream AM to downstream AV in the direction of circulation of the gases within the turbomachine 10, a fan 12, a low-pressure compressor 14a, a high-pressure compressor 14b, a combustion chamber 16, a high-pressure turbine 18a, a low-pressure turbine 18b and an exhaust nozzle 20. The high-pressure compressor 14b and the low-pressure compressor 14a are respectively connected to a high-pressure turbine 18a and to a low-pressure turbine 18b by a respective shaft extending in the longitudinal direction X of rotation of the shafts of the turbomachine.

[0003] In the following, orientation qualifiers, such as "longitudinal", "radial" and "circumferential" are defined with reference to the longitudinal axis X.

[0004] The air flow entering the turbomachine is divided, downstream of the fan 12, into a primary annular air flow entering a so-called primary annular vein 22a, and into a secondary annular air flow, entering a so-called secondary annular vein 22b which surrounds the primary annular air vein 22a. The low and high pressure compressors 14a, 14b, the combustion chamber 16 and the high and low pressure turbines 18a and 18b are located for the working parts in the primary annular vein 22a.

[0005] An exhaust casing 30 is located directly at the outlet of the low-pressure turbine 18b. The exhaust casing 30 comprises a radially inner shroud 32 and a radially outer shroud 34. An annular space formed between the inner shroud 32 and the outer shroud 34 forms a portion of the primary annular flow path 22a at the outlet of the low-pressure turbine 18b.

[0006] The exhaust nozzle 20, or ejection nozzle, of a turbomachine 10 conventionally comprises an assembly making it possible to optimize the flow of hot gases from the turbine. This assembly may also have the function of absorbing at least a portion noise generated by the interaction of these hot gases with the ambient air and with the flow of cold air from the blower.

[0007] The present description relates in particular to this assembly located at the rear, at the downstream end, and which comprises an ejection cone 40 comprising several parts, in particular an upstream part 40a, of substantially cylindrical shape and a downstream part 40b generally of conical shape.

[0008] Previous patent applications relating to the ejection cone are known, in particular FR 3 1 15 828 A1 which concerns the connection between said cone and the exhaust casing, and FR 3 1 15 835 A1 which concerns the means of fixing said cone.

[0009] More specifically, the present disclosure relates to the connection between different parts of the ejection cone 40.

[0010] With a view to reducing mass and using it at high temperatures for better performance of turbomachines, we are seeking to introduce new ceramic matrix composite materials (CMC) for the manufacture of certain parts, replacing the metal used until now.

[0011] However, these CMC materials have stiffness and expansion characteristics different from those of metal, which complicates their integration, particularly in a metallic environment, subject to large amplitude temperature variations.

[0012] In particular, the ejection cone 40 may be composed of several parts made of CMC material assembled together. Unlike metal parts, parts made of CMC material have low mechanical capacities, in particular do not allow significant deformation during assembly. When assembling the parts, it is therefore necessary to guarantee geometric maintenance of the parts to limit internal stresses and not damage the parts.

[0013] However, geometric deformations can be significant. Indeed, manufacturing processes can generate irregularities or dispersions of shape on finished parts that can reach several millimeters. These irregularities are all the more significant when the parts concerned have significant dimensions, which can be greater than about one meter, and when these parts have small thicknesses, which is likely to generate deformations during manufacturing.

[0014] Assembly models have been carried out. These show that there is a low tolerance for deformations in order to maintain an acceptable level of stress in the CMC material.

[0015] It is therefore necessary to limit the deformation of the parts, in particular of the parts forming part of the ejection cone 40, or rear body. Among these parts, we can distinguish in particular the upstream part 40a of the ejection cone 40 which comprises an upstream external annular wall 50 mounted around an upstream internal annular wall 51, as visible in Figures 2 and 4. The ejection cone 40 also comprises a downstream part 40b comprising a downstream external annular wall 52 also partially surrounding the upstream internal annular wall 51, as illustrated in Figures 2 and 4. Fixing screws F arranged in annular rows make it possible to fix the external walls 50 and 52 to the internal wall 51.

[0016] To limit the deformation of parts during assembly, it is known to propose solutions with low deformations and to possibly implement a solution by wedging which makes it possible to fill the gaps between parts and to contain the shape of the parts. Such a wedging can be solid or liquid.

[0017] The solid wedging, illustrated in Figure 3, consists of placing one or more shims C at certain locations between the parts, in this case between the upstream internal annular wall 51 and the upstream external annular wall 50 assembled together and each having geometric irregularities in their radial section, as visible. Along the illustrated section, we can see, in Figure 3, alternately contact zones between the external wall and the internal wall, at the level of the dotted lines shown, and clearance zones in which the shim C can be inserted as illustrated. Such wedging requires control and a choice of suitable shims, that is to say a tedious working method which makes the assembly operation less industrial. In addition, the solid wedging leads to losing the seal which results from an adjusted assembly between the two parts.

[0018] Liquid shimming, on the other hand, requires the development of a suitable interface. Furthermore, it is often limited in terms of thickness. Finally, liquid shimming requires a short implementation time, which is potentially incompatible with this step.

[0019] There is thus a need to have a turbomachine turbine assembly making it possible to limit, during assembly, the deformation of the parts, in particular those made, for at least some of them, from CMC material, in the ejection cone, taking into account the low mechanical capacities of the CMC, the differential expansion between CMC and metal, the simplicity of assembly and the limitation of the mass gain, and while guaranteeing the positioning of these parts so as to respect the profile of the aerodynamic vein. Summary

[0020] This disclosure improves the situation and aims to meet this need.

[0021] There is thus proposed a turbine assembly of a turbomachine with a longitudinal axis, comprising an ejection cone comprising an upstream part and a downstream part, the upstream part comprising an upstream inner annular wall and an upstream outer annular wall radially surrounding the upstream inner annular wall, the downstream part comprising a downstream outer annular wall, in which the upstream outer annular wall and the downstream outer annular wall are fixed to the upstream inner annular wall by means of a plurality of connecting members, said connecting members being elastically deformable at least in an axial direction and in a radial direction, said connecting members being arranged circumferentially, each connecting member being fixed to the upstream outer annular wall, to the downstream outer annular wall and to the upstream inner annular wall.

[0022] Thanks to the invention, and in particular thanks to the flexibility of the elastically deformable connecting members at least in a radial direction and an axial direction, the geometric irregularities of the external and internal walls can be compensated and therefore damage to the walls during assembly can be avoided. The presence of the connecting members forms a flexible connection system between the internal walls on the one hand and the external walls on the other. In addition, by minimizing the installation constraints in the walls made of CMC, the thermomechanical margins in operation are maximized. Furthermore, the elastically deformable connecting members allow elastic deformation in the radial direction and elastic deformation in the axial direction, these two deformations being independent of each other.

[0023] In addition, since the connecting members are used both for fixing the upstream internal annular wall to the upstream external annular wall, but also for fixing the upstream internal annular wall to the downstream external annular wall, the number of connecting members can be reduced and therefore a saving in the mass of connecting members required to ensure these fixings is obtained.

[0024] The features set out in the following paragraphs may, optionally, be implemented independently of each other or in combination with each other.

[0025] The connecting members advantageously comprise a metallic material. Each connecting member is preferably made from a single piece, i.e. from a single piece.

[0026] The dimensions of the connecting members are advantageously adapted to the loads and the engine context (temperature, available space in particular).

[0027] The rise in temperature during operation of the turbomachine generates an expansion of the connecting members causing a slight rotation of the annular walls external upstream and downstream around the longitudinal axis. This movement, however, has no impact on the profile of the aerodynamic vein.

[0028] Each connecting member advantageously comprises a first part and a second part. According to a preferred embodiment, each connecting member comprises a first part connecting the upstream internal annular wall to the upstream external annular wall and a second part connecting the upstream external annular wall to the downstream external annular wall.

[0029] Alternatively, the first part connects the upstream inner annular wall to the downstream outer annular wall and the second part connects the downstream outer annular wall to the upstream outer annular wall.

[0030] According to another variant, the first part connects the upstream internal annular wall to the upstream external annular wall and a second part connects the upstream internal annular wall to the downstream external annular wall.

[0031] The first part advantageously comprises a first fixing lug for fixing to a first of said walls, preferably to the upstream internal annular wall. The second part advantageously comprises a second fixing lug for fixing to a second of said walls, preferably to the downstream external annular wall. Each connecting member preferably comprises a third fixing lug for fixing to a third of said walls, preferably to the upstream external annular wall. At the third fixing lug are in particular connected the first and second parts of the connecting member, the first part comprising for example a first intermediate portion connecting the first fixing lug and the third fixing lug, the second part comprising for example a second intermediate portion connecting the second fixing lug and the third fixing lug.

[0032] In this case, and when the first part connects the upstream inner annular wall to the upstream outer annular wall and the second part connects the upstream outer annular wall to the downstream outer annular wall, the first fixing lug and the third fixing lug of the first part may extend from the first intermediate portion in opposite directions of the circumferential direction.

[0033] The first intermediate portion preferably has a generally planar shape and may have two ends attached to the first and third attachment tabs respectively, the first intermediate portion having a non-zero radial component. This makes it possible to keep the upstream inner annular wall at a distance from the upstream outer annular wall.

[0034] In this case, in a radial plane, an angle formed between the first fixing lug and the first intermediate portion is substantially equal to an angle formed between the third fixing lug and the first intermediate portion, at least in the unmounted state.

[0035] The unassembled state corresponds to a state in which the constituent parts of the ejection cone are not assembled together. The assembled state, on the other hand, corresponds to the state of the ejection cone with all its parts assembled and fixed together. We can also identify an unfixed state, which can be virtual, where the parts are assembled, but not yet fixed together.

[0036] When the first portion connects the upstream inner annular wall to the upstream outer annular wall and the second portion connects the upstream outer annular wall to the downstream outer annular wall, the second fixing lug and the third fixing lug may extend from the second intermediate portion in opposite directions of the axial direction.

[0037] In this case, the second intermediate portion may extend between two ends fixed to the second and third fixing lugs respectively, the second intermediate portion having for example a curved shape, in particular an arc of a circle, the second and third fixing lugs preferably having substantially the same radial coordinate, at least in an unfixed state.

[0038] Each connecting member advantageously has an L shape in top view with two branches connected by an angular part, the first and second parts respectively forming the branches of the L, being connected to each other at the angular part of the L.

[0039] In this case, the branches of the L extend approximately in directions perpendicular to each other.

[0040] The first part of the connecting members may extend substantially in a circumferential direction. The second part of the connecting members may extend substantially axially. In the latter case, and when the second part of the connecting members connects the upstream external annular wall and the downstream external annular wall, the fixing points on these two walls of the same connecting member preferably have substantially the same radial coordinate, at least in the absence of constraints.

[0041] The first, second and / or third fixing legs may be substantially parallel to each other in the unassembled state. This allows the inner and outer annular walls to be kept substantially parallel to each other in the assembled state.

[0042] The connecting members can be arranged in an annular row, the connecting members preferably being equally distributed over the annular circumference of the upstream internal annular wall. The angular distribution of the connecting members can allow the positioning of the walls to be controlled. The higher the number of connecting members, the more contained the shape. The number of connecting members depends on the size, in particular the diameter, of the parts, the diameter of the fixing screws used, the forces transmitted, and the design rules. It is therefore variable depending on the application. The number of connecting members can be approximately 40. The connecting members are preferably identical to each other.

[0043] The upstream outer annular wall may have a downstream end facing an upstream end of the downstream outer annular wall. Thus arranged, the upstream outer annular wall and the downstream outer annular wall form radially inwardly a flow surface for the primary air flow. The connecting members are preferably fixed near the downstream end of the upstream outer annular wall. The connecting members are also preferably fixed near the upstream end of the downstream outer annular wall. The connecting members are preferably configured to connect the downstream and upstream ends of the upstream outer annular wall and the downstream outer annular wall to each other, respectively, while making it possible to preserve the facing of these downstream and upstream ends.

[0044] The three fixing lugs advantageously respectively comprise openings for the passage of fixing elements, such as fixing screws, at least one of said openings having in particular an oblong shape, preferably the openings in the second fixing lug and in the third fixing lug are oblong in shape and the opening in the first fixing lug is circular.

[0045] The upstream inner annular wall may extend only under the upstream outer annular wall and not under the downstream outer annular wall. This makes it possible to reduce the length of the upstream inner annular wall compared to an embodiment where it would extend under the downstream outer annular wall, and therefore to reduce the mass of the assembly.

[0046] The turbine assembly may comprise a sealing gasket system inserted between, on the one hand, the upstream external annular wall and, on the other hand, the downstream external annular wall or the upstream internal annular wall.

[0047] The sealing joint system comprises, according to one embodiment, a braided seal, in particular of small transverse dimension, arranged radially between the connecting member, in particular at the level of the second intermediate portion, and the upstream and downstream external annular walls. The braided seal thus ensures sealing between the annular walls upstream and downstream external. The braided seal is for example arranged radially between the second intermediate portion and the upstream and downstream external annular walls. As an order of magnitude, the largest transverse dimension of the braided seal at rest can be between 5 and 15 mm.

[0048] The sealing joint system comprises, according to another embodiment, a braided seal, in particular of large transverse dimension, extending radially between the upstream internal annular wall and the upstream external annular wall, and in particular extending circumferentially. The braided seal is for example arranged axially upstream of the first part, of the connecting members. As an order of magnitude, the largest transverse dimension of the braided seal, in this case, at rest, can be between 20 and 40 mm, i.e. a dimension equivalent to the radial height of the connecting member.

[0049] In the latter case, the sealing joint system may comprise a support for the braided seal partially interposed radially between, on the one hand, the upstream internal annular wall and, on the other hand, the connecting member and the braided seal, said support comprising a portion substantially parallel to the upstream internal annular wall and a curved portion extending radially, configured to axially retain the braided seal. The assembly of the support and the braided seal makes it possible to ensure sealing with an acoustic cavity which is located upstream in the ejection cone.

[0050] The downstream external annular wall is advantageously conical, for example frustoconical.

[0051] The upstream external annular wall comprises, for example, two half-rings assembled together so as to at least partially cover the upstream internal annular wall, in particular to completely cover a circumference of said upstream internal annular wall and at least partially axially said upstream internal annular wall.

[0052] The upstream outer annular wall, the downstream outer annular wall and / or the upstream inner annular wall is / are for example made of a ceramic matrix composite (CMC) material, preferably the upstream outer annular wall, the downstream outer annular wall and the upstream inner annular wall are made of a CMC material.

[0053] According to another aspect, there is provided a turbine comprising a turbine assembly as defined above.

[0054] According to another aspect, a turbomachine is provided comprising a turbine as defined above. Brief description of the drawings

[0055] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analyzing the attached drawings, in which:

[0056] [Fig. 1] is a schematic axial sectional view of a turbomachine, in particular according to the invention,

[0057] [Fig. 2] is a schematic perspective view of detail II of Figure 1, namely an ejection cone of a turbomachine, shown in assembled form according to the prior art,

[0058] [Fig. 3] is a schematic cross-sectional view along III of the ejection cone of Figure 2,

[0059] [Fig. 4] is a schematic axial sectional view of detail IV of the ejection cone of Figure 2,

[0060] [Fig. 5] is a schematic exploded perspective view of an example of an ejection cone according to the invention forming part of a turbine assembly of a turbomachine as illustrated in FIG. 1,

[0061] [Fig. 6] is a schematic side view of the ejector cone of Figure 5, partially assembled,

[0062] [Fig. 7] illustrates in isolation in a schematic perspective view an example of a connecting member of the ejection cone of figure 5,

[0063] [Fig. 8] shows schematically a partial cross-section along AA shown in Fig. 7 of the ejection cone of Fig. 5,

[0064] [Fig. 9] is a partial, schematic top view of the connecting members used to secure the walls in the ejector cone of Figure 5,

[0065] [Fig. 10] is a partial, schematic, perspective top view of the connecting members used to secure the walls in the ejector cone of Figure 5,

[0066] [Fig. 11] is a schematic, perspective, partial view of the ejection cone of Figure 5,

[0067] [Fig. 12] is a schematic, perspective, partial view of the ejection cone of Figure 5,

[0068] [Fig. 13] is a schematic, partial, sectional and perspective view of an example of a sealing system of an ejection cone according to the invention, and

[0069] [Fig. 14] is a schematic, partial, sectional and perspective view of another example of a sealing system of an ejection cone according to the invention. Description of the embodiments

[0070] 5 shows the ejection cone 40 of a turbine assembly for a turbomachine 10 such as that illustrated in FIG. 1, the ejection cone 40 comprising an upstream portion 40a and a downstream portion 40b. The upstream portion 40a comprises an upstream inner annular wall 51 and an upstream outer annular wall 50 radially surrounding the upstream inner annular wall 51. In this example, the upstream outer annular wall 50 comprises two half-rings 50a and 50b which are assembled together around the upstream inner annular wall 51 using two fixing pieces 53 arranged diametrically opposite one another. The downstream portion 40b comprises a downstream external annular wall 52. In this example, the downstream external annular wall 52 is conical in shape, with in particular, as visible in FIG. 6, the truncated conical end. In the example illustrated, all of the walls 50, 51 and 52 are made of a ceramic matrix composite (CMC) material.

[0071] To assemble the walls 50, 51 and 52 together, the turbine assembly comprises elastically deformable connecting members 60 at least in an axial direction and in a radial direction to fix the upstream external annular wall 50 and the downstream external annular wall 52 to the upstream internal annular wall 51. The connecting members 60 are arranged circumferentially, each connecting member 60 being fixed to the upstream external annular wall 50, to the downstream external annular wall 52 and to the upstream internal annular wall 51. In the example illustrated, the connecting members 60 are identical to each other.

[0072] Thanks to the presence of the connecting members 60 and their flexibility, the geometric dispersions of the upstream external annular walls 50 and downstream 52 and of the upstream internal annular wall 51 are compensated.

[0073] In addition, by minimizing the installation constraints in the walls made of CMC, in this example walls 50, 51 and 52, we maximize the thermomechanical margins in operation.

[0074] In the example illustrated in Figures 5 to 14, each connecting member 60 is made in a single piece from a metallic material. The connecting member 60 comprises a first part 60a and a second part 60b, the first part 60a connecting the upstream internal annular wall 51 to the upstream external annular wall 50 and the second part 60b connecting the upstream external annular wall 50 to the downstream external annular wall 52.

[0075] It is not beyond the scope of the invention if the first part connects the upstream inner annular wall 51 to the downstream outer annular wall 52 and the second part connects the downstream outer annular wall 52 to the upstream outer annular wall 50. It is also not beyond the scope of the invention if the first part connects the upstream inner annular wall 51 to the upstream outer annular wall 50 and the second part connects the upstream inner annular wall 51 to the downstream outer annular wall 52.

[0076] As illustrated in Figure 7 in particular, the first part 60a comprises a first fixing lug 61 for fixing to the upstream internal annular wall 51. The second part 60b comprises a second fixing lug 62 for fixing to the downstream external annular wall 52. The connecting member 60 further comprises a third fixing lug 70 for fixing to the upstream external annular wall 50. This third fixing lug 70 connects the first and second parts 60a and 60b. The first part 60a comprises a first intermediate portion 63 connecting the first fixing lug 61 and the third fixing lug 70. The second part 60b comprises a second intermediate portion 66 connecting the second fixing lug 62 and the third fixing lug 70.

[0077] In the illustrated example, each connecting member 60 has, in top view, an L shape with two branches connected by an angular part. The first and second parts 60a and 60b respectively form the branches of the L, being connected to each other at the angular part, occupied in this example by the third fixing lug 70 as visible in particular in FIG. 6. The branches of the L extend substantially in directions perpendicular to each other.

[0078] The width of the first part 60a of the connecting member 60 at the first intermediate portion 63 is for example equal to 30 mm. The width of the second part 60b of the connecting member 60 at the second intermediate portion 66 is preferably equal to the width of the first part 60a in the first intermediate portion 63. The length of the intermediate portion 63 may be equal to 42 mm, the length of the second intermediate portion 66 may be equal to 30 mm when not deployed. The thickness of each connecting member 60 may be constant, being approximately equal to 1 mm.

[0079] In the illustrated example, the first fixing lug 61 and the third fixing lug 70 of the first part 60a extend from the first intermediate portion 63 in opposite directions of the circumferential direction, as can be seen for example in FIG. 8.

[0080] The first intermediate portion 63 has a generally planar shape in the illustrated example and comprises two ends 64 and 65 fixed to the first and third fixing lugs 61 and 70 respectively, the first intermediate portion 63 having a non-zero radial component. Thus, there is a difference in height H radially between the fixing lugs 61 and 70. In this example, H is equal to approximately 30 mm in the unmounted state. The height H is of course variable due to the radial elasticity of the connecting member 60 and the radial and / or axial stresses to which the connecting member 60 is subjected when taken between the upstream internal annular wall 51 and the upstream external annular wall 50.

[0081] As seen in Figure 8, in a radial plane, an angle α formed between the first fixing lug 61 and the first intermediate portion 63 is substantially equal to an angle P formed between the third fixing lug 70 and the first intermediate portion 63, at least in the unmounted state. The angles α and P are equal to 135° in the unmounted state in this example.

[0082] The second fixing lug 62 and the third fixing lug 70 extend from the second intermediate portion 66 in opposite directions of the axial direction. The second intermediate portion 66 extends between two ends 67 and 68 fixed to the second and third fixing lugs 62 and 70 respectively, the second intermediate portion 66 having a curved shape, in this example an arc of a circle, the second and third fixing lugs 62 and 70 having the same radial coordinate, at least in an unfixed state. This makes it possible to maintain the upstream 50 and downstream 52 outer annular walls substantially at the same radial distance from the longitudinal axis X, being connected to each other by the connecting members 60 fixed to the walls 50 and 52 using the fixing lugs 70 and 62.

[0083] The upstream external annular wall 50 has a downstream end 82 opposite an upstream end 83 of the downstream external annular wall 52 as visible for example in FIG. 9.

[0084] The three fixing lugs 61, 62 and 70 comprise openings 71, 72 and 73 respectively for the passage of fixing elements, such as fixing screws, not visible in the figures for the sake of clarity of the drawing. The fixing screws may be of the type illustrated in FIG. 4 in order to fix the fixing lug concerned to the corresponding wall. In the example illustrated, the opening 71 is circular in shape while the openings 72 and 73 have oblong shapes in a circumferential direction. The oblong shapes make it easier to mount and fix the connecting member 60 to the upstream external annular wall 50 and downstream external annular wall 52, in particular to compensate for geometric irregularities of the walls. It is not outside the scope of the invention if the opening 71 is oblong in shape or if the openings 72 and 73 are circular.

[0085] The first, second and third fixing lugs 61, 62 and 70 are substantially parallel to each other in the unmounted state in the illustrated example. Each fixing lug 61, 62 and 70 extends against the wall 51, 52, 50 on which it is fixed, being in contact over its entire surface with this wall, the external walls 50 and 52 being held substantially parallel to the internal wall 51 by the connecting members 60, as illustrated in FIG. 8. The external walls 50 and 52 are further held at a non-zero distance from the internal wall thanks to the intermediate portion 63 which has a non-zero radial component.

[0086] As can be seen in Figure 11, the upstream inner annular wall 51 extends only under the upstream outer annular wall 50 and not under the downstream outer annular wall 52 in this example. Thanks to this aspect of the invention, the mass of the ejection cone 40 can be reduced. Indeed, it is not necessary for the upstream inner annular wall 51 to extend under the downstream outer annular wall 52 since these two walls are fixed to each other by means of the second part 60b of the connecting members 60, the first part 60a being fixed to the upstream outer annular wall 50 and upstream inner annular wall 51.

[0087] The connecting members 60 are, as can be seen for example in Figures 9, 10, 11 or 12, arranged in an annular row 80 extending in a circumferential direction. Thus, as can be seen, all the first parts 60a of the connecting members 60 are arranged in a circumferential direction while all the second parts 60b extend in an axial direction, all directed in the same direction. The first parts 60a of the connecting members 60 are located near the downstream end 82 of the upstream external annular wall 50, in this example at a distance equal to approximately 25 mm, substantially parallel to this downstream end 82. The fixing elements, in particular the fixing screws, form a crown which ensures that the walls 50, 51 and 52 are held in position, after assembly and fixing.The minimum spacing provided by the connecting members 60 between the internal walls 51 on the one hand and the external walls 50 and 52 on the other hand is designed to be compatible with the chosen fixing elements.

[0088] Fixing points 85 and 86 made respectively on the upstream outer annular wall 50 and the downstream outer annular wall 52 for the respective fixing of the third and second fixing lugs 70 and 62 have the same radial coordinate, that is to say are located at the same level of the annular circumference. Washers can be positioned around the fixing points 85 and 86, being interposed between the fixing elements and the walls concerned.

[0089] The flexibility of the connecting members 60 is notably linked to their shape, their thickness, the material with which they are made. Thus, the shape, the thickness and the material and possibly other parameters of the connecting members 60 are chosen so as to obtain the desired elasticity for the connecting members 60.

[0090] The rise in temperature during operation of the turbomachine 10 generates an expansion of the connecting members 60 causing a slight rotation of the upstream 50 and downstream 52 external annular walls around the longitudinal axis X as indicated with the arrow D in figure 8. This movement has no impact on the profile of the aerodynamic vein.

[0091] The rise in temperature also generates an expansion of the connecting members 60 which causes a slight translation of the upstream 50 and downstream 52 external annular walls along the longitudinal axis X. This movement can degrade the profile of the aerodynamic vein but since the second part 60b of the connecting members 60 is used to fix the downstream external annular wall 52 whose profile is of second order for the aerodynamic vein, this translation movement has a reduced impact on the profile of the aerodynamic vein.

[0092] The turbine assembly may also include a sealing joint system 90 interposed between the upstream outer annular wall 50 and downstream outer annular wall 52 on the one hand and the upstream inner annular wall 51 on the other hand.

[0093] According to a first embodiment illustrated in Figure 13, the sealing joint system 90 comprises a braided joint of small transverse dimension 91 arranged between the connecting member 60, housed in this case at the level of the second intermediate portion 66 in the hollow formed by the curved part, and the downstream external annular wall 52 and / or upstream 50, in particular at the level of the upstream 82 and downstream 83 ends of the upstream 50 and downstream 51 external annular walls respectively. The largest transverse dimension of the joint 91 of small transverse dimension may be at rest equal to 15 mm. Thus, the seal is ensured in particular at the level of the zone situated between the downstream 82 and upstream 83 ends of the upstream 50 and downstream 52 external annular walls respectively.

[0094] In the example illustrated in Figure 14, in addition to the braided seal of small transverse dimension 91, the sealing joint system 90 comprises a braided seal of large transverse dimension 92 extending circumferentially and arranged upstream of the connecting members 60 along the longitudinal axis X, between the upstream external annular wall 50 and the upstream internal annular wall 51, the largest transverse dimension of the braided seal of large transverse dimension being equal at rest in this example to 30 mm.

[0095] Still in the example illustrated in Figure 14, the sealing joint system 90 comprises a support 93 of the braided joint of large transverse dimension 92 interposed between on the one hand the upstream internal annular wall 51 and on the other hand the connecting member 60 and the joint large transverse braid 92, said support 93 comprising a portion 94 substantially parallel to the upstream internal annular wall 51 and a curved portion 95 extending radially configured to axially retain the large transverse braid seal 92, being in contact with it, as visible. The assembly of the support 93 and the large transverse braid seal 92 makes it possible to ensure sealing with an acoustic cavity which is located upstream in the ejection cone 40.

[0096] The invention also relates to the turbomachine 10 illustrated in FIG. 1, described above when it comprises a machine assembly as described above with an ejection cone 40 whose parts are assembled in particular thanks to the connecting members 60, as well as the turbine of such a turbomachine 10.

[0097] This disclosure is not limited to the examples described above, solely by way of example, but it encompasses all the variations that a person skilled in the art may envisage within the framework of the protection sought.

Claims

Claims

1. A turbomachine turbine assembly (10) with a longitudinal axis (X), comprising an ejection cone (40) comprising an upstream portion (40a) and a downstream portion (40b), the upstream portion (40a) comprising an upstream inner annular wall (51) and an upstream outer annular wall (50) radially surrounding the upstream inner annular wall (51), the downstream portion (40b) comprising a downstream outer annular wall (52), wherein the upstream outer annular wall (50) and the downstream outer annular wall (52) are fixed to the upstream inner annular wall (51) by means of a plurality of connecting members (60), said connecting members (60) being elastically deformable at least in an axial direction and in a radial direction, said connecting members (60) being arranged circumferentially, each connecting member (60) being fixed to the upstream external annular wall (50), to the downstream external annular wall (52) and to the upstream internal annular wall (51).

2. A turbine assembly according to claim 1, wherein each connecting member (60) comprises a first portion (60a) and a second portion (60b), namely a first portion (60a) connecting the upstream inner annular wall (51) to the upstream outer annular wall (50) and a second portion (60b) connecting the upstream outer annular wall (50) to the downstream outer annular wall (52), or a first part (60a) connecting the upstream inner annular wall (51) to the downstream outer annular wall (52) and a second part (60b) connecting the downstream outer annular wall (52) to the upstream outer annular wall (50), or a first part (60a) connecting the upstream inner annular wall (51) to the upstream outer annular wall (50) and a second part (60b) connecting the upstream inner annular wall (51) to the downstream external annular wall (52), preferably the first part (60a) connecting the upstream internal annular wall (51) to the upstream external annular wall (50) and the second part (60b) connecting the upstream external annular wall (50) to the downstream external annular wall (52).

3. Turbine assembly according to the preceding claim, wherein said first part (60a) comprises a first fixing lug (61) for fixing to a first of said walls (50; 51; 52), preferably to the upstream internal annular wall (51), said second part (60b) comprises a second fixing lug (62) for fixing to a second of said walls (51; 52, 50), preferably to the annular wall downstream external wall (52), each connecting member (60) comprising a third fixing lug (70) for fixing to a third of said walls (52; 50; 51), preferably to the upstream external annular wall (50), third fixing lug (70) at which the first and second parts (60a, 60b) are connected, the first part (60a) comprising a first intermediate portion (63) connecting the first fixing lug (61) and the third fixing lug (70), the second part (60b) comprising a second intermediate portion (66) connecting the second fixing lug (62) and the third fixing lug (70).

4. Turbine assembly according to the preceding claim, the first part (60a) connecting the upstream inner annular wall (51) to the upstream outer annular wall (50) and the second part (60b) connecting the upstream outer annular wall (50) to the downstream outer annular wall (52), wherein the first fixing lug (61) and the third fixing lug (70) of the first part (60a) extend from the first intermediate portion (63) in opposite directions of the circumferential direction.

5. Turbine assembly according to the preceding claim, in which the first intermediate portion (63) preferably has a generally planar shape and comprises two ends (64, 65) fixed to the first and third fixing lugs respectively, the first intermediate portion having a non-zero radial component.

6. A turbine assembly according to any one of claims 3 to 5, the first portion (60a) connecting the upstream inner annular wall (51) to the upstream outer annular wall (50) and the second portion (60b) connecting the upstream outer annular wall (50) to the downstream outer annular wall (52), wherein the second fixing lug (62) and the third fixing lug (70) extend from the second intermediate portion (66) in opposite directions of the axial direction.

7. Turbine assembly according to the preceding claim, in which the second intermediate portion (66) extends between two ends (67, 68) fixed to the second and third fixing lugs (62, 70) respectively, the second intermediate portion (66) having a curved shape, in particular an arc of a circle, the second and third fixing lugs (62, 70) having substantially the same radial coordinate, at least in an unfixed state.

8. A turbine assembly according to any one of claims 2 to 7, wherein each connecting member (60) has an L shape in top view with two branches connected by an angular portion, said first and second portions (60a, 60b) respectively forming the branches of the L, being connected to each other at the angular portion of the L.

9. A turbine assembly according to any one of claims 3 to 8, wherein the first, second and / or third fixing lugs (61, 62, 70) are substantially parallel to each other in the unmounted state.

10. A turbine assembly according to any one of claims 3 to 9, wherein the three fixing lugs (61, 62, 70) respectively comprise openings (71, 72, 73) for the passage of fixing elements, such as fixing screws, at least one of said openings (71, 72, 73) having in particular an oblong shape, preferably the openings (72, 73) in the second fixing lug (62) and in the third fixing lug (70) are oblong in shape and the opening (71) in the first fixing lug (61) is circular.

11. Turbine assembly according to any one of the preceding claims, comprising a sealing joint system (90) interposed between, on the one hand, the upstream external annular wall (50) and, on the other hand, the downstream external annular wall (52) or the upstream internal annular wall (51).

12. Turbine assembly according to claims 3 and 11, in which the sealing joint system (90) comprises a braided joint (91) arranged radially between the connecting member (60), in particular at the level of the second intermediate portion (66), and the upstream (50) and downstream (52) external annular walls.

13. A turbine assembly according to claim 11 or 12, wherein the seal system comprises a braided seal (92) extending radially between the upstream inner annular wall (51) and the upstream outer annular wall (50).

14. Turbine assembly according to claim 13, in which the seal system (90) comprises a support (93) of the braid seal (92) partially interposed radially between on the one hand the upstream internal annular wall (51) and on the other hand the connecting member (60) and the braid seal (92), said support (93) comprising a part (94) substantially parallel to the upstream internal annular wall (51) and a curved part (95) extending radially, configured to axially retain the braid seal (92).

15. A turbine assembly according to any preceding claim, wherein the upstream outer annular wall (50), the downstream outer annular wall (52) and / or the upstream inner annular wall (51) is / are made of a ceramic matrix composite (CMC) material, preferably the upstream outer annular wall (50), the downstream outer annular wall (52) and the upstream inner annular wall (51) are made of a CMC material.

16. A turbine comprising a turbine assembly according to any preceding claim.

17. A turbomachine comprising a turbine according to claim 16.

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