Assembly for turbomachine

Abstract

Assembly (30) for a turbomachine with a longitudinal axis (X1), the assembly (30) comprising at least a first element including a first annular flange (31) about the longitudinal axis (X1) and a second element including a second annular flange (32) about the longitudinal axis (X1), the assembly (30) including an annular sealing sleeve (40) covering a peripheral portion of the first flange (31) and the second flange (32), the sealing sleeve (40) including a longitudinal wall (41) adapted to deform elastically radially inwards during a relative displacement of the first flange (31) with respect to the second flange (32) so as to remain jointly and radially sealed against a radially external face (31c) of the first flange (31) and a radially external face (32c) of the second flange (32). Figure 4

Description

Title of the invention: Turbomachine assembly Technical field

[0001] The present description relates to a turbomachine assembly comprising a sealed flange connection and to a turbomachine comprising such an assembly. Prior art

[0002] A turbomachine 10, as shown in [Fig.l], conventionally has a longitudinal axis XI which corresponds to the axis of rotation of the rotating parts. The turbomachine 10 comprises, from upstream AM to downstream AV in the direction of gas flow, a fan 11, a low-pressure compressor 12, a high-pressure compressor 13, a combustion chamber 14, a high-pressure turbine 15 and a low-pressure turbine 16. The air from the fan 11 is divided into a primary flow flowing in a primary annular vein, and a secondary flow flowing in a secondary annular vein surrounding the primary annular vein. The low-pressure compressor 12, the high-pressure compressor 13, the combustion chamber 14, the high-pressure turbine 15 and the low-pressure turbine 16 are arranged in the primary vein.

[0003] The rotor of the high-pressure turbine 15 and the rotor of the high-pressure compressor 13 are rotationally coupled via a first shaft 17 so as to form a high-pressure body. The rotor of the low-pressure turbine 16 and the rotor of the low-pressure compressor 12 are rotationally coupled via a second shaft 18 so as to form a low-pressure body, the fan 11 being able to be connected directly to the rotor of the low-pressure compressor or for example via an epicyclic gear train.

[0004] In the present disclosure, the longitudinal direction X corresponds to the direction of the longitudinal axis XL. The longitudinal axis XI coincides with an axis of rotation of the rotor parts of the turbomachine. Orientation qualifiers, such as “longitudinal”, “radial” or “circumferential” are defined, unless otherwise specified, by reference to the longitudinal axis XL. A radial direction R is a direction perpendicular to the direction of the longitudinal axis XL. A circumferential direction, at a point distant from the longitudinal axis XI, corresponds to a direction perpendicular to the longitudinal and radial directions. Furthermore, unless otherwise specified, the adjectives “inner”, “inner”, “outer” and “outer” are used with reference to a radial direction R so that the inner / inner part (i.e. radially inner / inner) of an element is closer to the longitudinal axis XI than the outer / outer part (i.e.radially external / radially external) of the same element. Finally, the relative qualifiers. “Upstream” and “downstream” are defined in relation to the normal flow direction of the fluid (from upstream to downstream) in the turbomachine.

[0005] To assemble turbomachine components subjected to significant pressure, such as casings or compressor or turbine elements, it is known to use sealed connections with radial annular flanges 21, 22 assembled to each other by bolting 23 as shown in [Fig. 2]. The flanges 21, 22 bear against each other in the radial direction and / or the longitudinal direction. The flanges define between them a housing 24 in which a sealing system is inserted, such as an annular O-ring 25 to prevent the passage of a fluid (for example air or oil) between the flanges from the inside to the outside.

[0006] However, turbomachine components are generally subjected to significant mechanical and / or thermal forces, which can lead to a separation of the flanges 21, 22 forming a passage 26 longitudinally between the flanges, as shown in [Fig. 3]. Such a separation of the flanges 21, 22 has the effect that the seal 25 is no longer clamped between the flanges 21, 22 so that sealing is no longer ensured. This results in a leak of the fluid radially outwards through the passage 26 which can harm the performance of the turbomachine or possibly compromise its integrity. Summary

[0007] An assembly for a turbomachine with a longitudinal axis is proposed, the assembly comprising at least a first element comprising a first annular flange around the longitudinal axis and a second element comprising a second annular flange around the longitudinal axis, the first flange and the second flange each comprising at least a first face and a second face opposite one another in the longitudinal direction, the second face of the first flange being applied to the first face of the second flange in the longitudinal direction, the assembly comprising an annular sealing sleeve covering a peripheral portion of the first flange and the second flange, the sealing sleeve comprising an annular longitudinal wall applied radially inwards in a sealed manner jointly on a radially external face of the first flange and a radially external face of the second flange,the longitudinal wall of the sealing sleeve being adapted to deform elastically radially inwards during a relative movement of the first flange with respect to the second flange to remain applied in a sealed manner jointly on the radially external face of the first flange and the radially external face of the second flange.

[0008] Thus, the sealing sleeve makes it possible to ensure a sealed connection between the first flange and the second flange, even if a relative movement between the first flange and the second flange occurs under the effect of mechanical and / or thermal forces. The sealing sleeve makes it possible to prevent the passage of fluid, such as oil or air, longitudinally between the first flange and the second flange, in particular radially from the inside to the outside.

[0009] The longitudinal wall may extend in a direction comprising at least one component in the longitudinal direction. The longitudinal wall of the sealing sleeve may be adapted to flex radially inward. The sealing sleeve may be sectorized around the longitudinal axis. Preferably, tangential overlap extensions between the sectors of the sleeve will ensure mechanical sealing.

[0010] The relative displacement between the first flange and the second flange may result from a deformation of the first flange and / or the second flange under the effect of mechanical and / or thermal forces. The relative displacement between the first flange and the second flange may lead to a separation of the flanges relative to each other in the longitudinal direction and form a passage longitudinally between the first flange and the second flange, in particular at a radially internal portion of the first flange and the second flange.

[0011] The first flange may be an upstream flange and the second flange may be a downstream flange. In other words, the first flange may be longitudinally upstream of the second flange, and conversely the second flange may be longitudinally downstream of the first flange.

[0012] The first flange and the second flange may define a first annular groove opening radially outwards, the assembly comprising an annular sealing member received at least in part in the first groove so as to prevent fluid from passing longitudinally between the first flange and the second flange. The elastic deformation of the longitudinal wall of the sealing sleeve may make it possible to maintain the sealing member in the first groove.

[0013] The sealing member makes it possible to further improve the sealing between the first flange and the second flange. The sealing member is held in the first groove by the fact that the longitudinal wall of the sealing sleeve can deform radially inwards, preventing its removal from the first groove and a loss of sealing.

[0014] The first groove may be formed in part by the first flange and the second flange.

[0015] The sealing member can be received by form-fitting in the first groove.

[0016] The sealing member may be a relief formed in one piece with the sealing sleeve and projecting radially towards the inside of the longitudinal wall of the sealing sleeve.

[0017] This makes it possible to avoid relative movement between the sealing sleeve and the member sealing that could affect the seal. The sealing sleeve and the sealing member may be made of a metallic material. Such a sealing member is particularly suitable for a hot environment.

[0018] The sealing member may be an annular seal around the longitudinal axis, for example an O-ring, separate from the sealing sleeve and adapted to be constrained in the first groove.

[0019] Such a solution further improves the sealing. The sealing member can be made of elastomer. Such a sealing member is particularly suitable for a cold environment.

[0020] The longitudinal wall of the sealing sleeve may comprise a second annular groove around the longitudinal axis in which the annular seal is partially received. The second groove may be formed in a radially inner face of the longitudinal wall.

[0021] The longitudinal wall of the sealing sleeve may comprise a radially outer face which is, in section, curved concavely radially outwards. This makes it easier to deform the longitudinal wall radially inwards.

[0022] The sealing sleeve may be held to the first flange and the second flange by first clamping means.

[0023] The sealing sleeve may comprise a first side wall extending radially inward from the longitudinal wall and applied longitudinally in a sealing manner against the first face of the first flange and a second side wall extending radially inward from the longitudinal wall and applied longitudinally in a sealing manner against the second face of the second flange. The sealing provided by the sealing sleeve is thus further improved.

[0024] The sealing sleeve may have a U-shaped section.

[0025] The first side wall and the second side wall may extend in a direction comprising at least one component in the radial direction. In an undeformed configuration, the first side wall and the second side wall may extend in the radial direction.

[0026] The sealing sleeve may include a first annular notch formed at the junction between the longitudinal wall and the first side wall and a second annular notch formed at the junction between the longitudinal wall and the second side wall.

[0027] The notches, or cutouts, facilitate the deformation of the longitudinal wall radially inward. The notches provide mechanical flexibility to the sealing sleeve at the junction between the longitudinal wall and each of the first side wall and the second side wall. Whereby, the first side wall and the second side wall can be oriented to remain applied in a sealed manner respectively on the first face of the first flange and the second face of the second flange.

[0028] The sealing sleeve comprises an inner face comprising by one face of the first side wall applied against the first face of the first flange, a radially inner face of the longitudinal wall and a face of the second side wall applied against the second face of the second flange. Each notch can be formed at the inner face of the sealing sleeve. In other words, each notch can open at the inner face of the sealing sleeve. The annular edge connecting the longitudinal wall and the first side wall can open into a first annular housing. The annular edge connecting the longitudinal wall and the second side wall can open into a second annular housing.

[0029] The sealing sleeve may be a stamped sheet metal. The junction between the longitudinal wall and each of the first wall and the second wall may be formed by a fold line.

[0030] Each notch may be, in section, of rounded shape.

[0031] The first clamping means may comprise an annular row of bolts, one screw of each bolt passing longitudinally through the first side wall of the sealing sleeve, the first flange, the second flange and the second side wall of the sealing sleeve.

[0032] The head of the screw of each bolt may bear longitudinally on a face of the first side wall longitudinally opposite the first flange and a nut of each bolt may be screwed onto the screw and bear longitudinally on a face of the second side wall longitudinally opposite the second flange.

[0033] According to a first possibility, the first clamping means are configured to clamp the flanges together longitudinally. In other words, the first clamping means allow the second face of the first flange to be applied against the first face of the second flange. This makes it possible to pool the clamping means for the flanges and the sealing sleeve, to reduce the mass of the assembly.

[0034] According to a second possibility, the assembly may comprise second clamping means distinct from the first clamping means and configured to longitudinally clamp the flanges together. The second clamping means may comprise an annular row of bolts, one screw of each bolt passing longitudinally through the first flange and the second at a portion of the first flange and the second flange located radially inward relative to the sealing sleeve. In other words, the screw of each bolt of the second clamping means does not pass through the first side wall and the second side wall of the sealing sleeve, the walls being for example notched or the clamping means installed at different radial heights. The head of the screw of each bolt of the second clamping means may bear longitudinally on the first face of the first flange and a nut of each bolt of the second clamping means may be screwed onto the screw and bear longitudinally on the second face of the second flange. The second clamping means may have a tightening, or tightening torque, in the longitudinal direction greater than that of the first clamping means.

[0035] The assembly may comprise first sealing means interposed longitudinally between the first side wall of the sealing sleeve and the first face of the first flange and / or second sealing means interposed longitudinally between the second face of the second flange and the second side wall of the sealing sleeve. This makes it possible to further improve the sealing of the assembly.

[0036] The first sealing means may comprise an annular row of seals, preferably O-rings, each being arranged around a screw of one of the bolts of the first clamping means. The second sealing means may comprise an annular row of seals, preferably O-rings, each being arranged around a screw of one of the bolts of the first clamping means.

[0037] According to another aspect, a turbomachine is described comprising an assembly as described above.

[0038] According to a first possibility, the first element may be an upstream disk of a turbine or compressor rotor assembly and the second element may be a downstream disk of the turbine or compressor rotor assembly.

[0039] According to a second possibility, the first element may be a first part of a shaft of the turbomachine and the second element may be a second part of a shaft of the turbomachine. The shaft may extend in the longitudinal direction. The longitudinal axis may be an axis of revolution of the shaft. The shaft may pivot about the longitudinal axis.

[0040] According to a third possibility, the first element may be a first casing of the turbomachine and the second element may be a second casing of the turbomachine. The first casing and the second casing may surround rotating parts of the turbomachine such as a compressor or a turbine. Brief description of the drawings

[0041] Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the attached drawings, in which:

[0042] [Fig-1] represents a sectional view of a turbomachine according to the known state of the art.

[0043] [Fig.2] represents a sectional view of a sealed flanged connection according to the state of the known technique.

[0044] [Fig.3] represents a sectional view of the connection of [Fig.2] in which a passage is formed between the flanges.

[0045] [Fig.4] represents a sectional view of a set of flanges provided with an element sealing according to a first embodiment of the present description.

[0046] [Fig.5] represents a sectional view of the flange assembly provided with the element sealing according to the first embodiment in a deformed configuration.

[0047] [Fig.6] comprises Figures 6a and 6b. Figure 6a shows a sectional view of the flange assembly provided with the sealing element according to a second embodiment of the present description. Figure 6b shows a sectional view of the flange assembly provided with the sealing element according to the second embodiment in a deformed configuration.

[0048] [Fig.7] represents a sectional view of the flange assembly provided with the element sealing according to a third embodiment of the present description and in a deformed configuration. Description of the embodiments

[0049] Reference is now made to Figures 3 to 7 which represent an assembly for a turbomachine with a longitudinal axis XL. The assembly 30 comprises a first element which comprises a first annular flange 31 around the longitudinal axis XI and a second element which comprises a second annular flange 32 around the longitudinal axis XL. The first element and the second element are connected together at least via the first flange 31 and the second flange 32. To do this, the first flange 31 and the second flange 32 each comprise a first face 31a, 32a and a second face 31b, 32b opposite each other in the longitudinal direction X, the second face 31b of the first flange 31 being applied to the first face 32a of the second flange 32 in the longitudinal direction X. As described below in more detail, the assembly 30 comprises clamping means adapted to clamp and connect the first flange 31 and the second flange 32.

[0050] According to the illustrated example, the first flange 31 is an upstream flange and the second flange 32 is a downstream flange. In other words, the first flange 31 is longitudinally upstream of the second flange 32, and conversely the second flange 32 is longitudinally downstream of the first flange 31.

[0051] According to a first possibility, the first element may be an upstream disk of a turbine or compressor rotor assembly 30 and the second element may be a downstream disk of the turbine or compressor rotor assembly 30.

[0052] According to a second possibility, the first element can be a first part of a shaft of the turbomachine and the second element can be a second part of a turbomachine shaft. The shaft can extend in the longitudinal direction. The longitudinal axis XI can be an axis of revolution of the shaft. The shaft can pivot around the longitudinal axis XL

[0053] According to a third possibility, the first element may be a first casing of the turbomachine and the second element may be a second casing of the turbomachine. The first casing and the second casing may surround rotating parts of the turbomachine such as a compressor or a turbine.

[0054] The first flange 31 is connected in a sealed manner to the second flange 32 to prevent the passage of a fluid such as air or oil longitudinally between the first flange 31 and the second flange 32, in particular radially from the inside to the outside. Figures 4 and 5 show a first embodiment of a sealed connection between the first flange 31 and the second flange 32.

[0055] According to the first embodiment, the assembly 30 comprises an annular sealing sleeve 40 covering a peripheral portion of the first flange 31 and the second flange 32. The sealing sleeve 40 comprises an annular longitudinal wall 41 applied radially inward in a sealing manner jointly on a radially external face 31c of the first flange 31 and a radially external face 32c of the second flange 32. The sealing sleeve 40 also comprises a first lateral wall 43 extending radially inward from the longitudinal wall 41 and applied longitudinally in a sealing manner against the first face 31a of the first flange 31 and a second lateral wall 44 extending radially inward from the longitudinal wall 41 and applied longitudinally in a sealing manner against the second face 32b of the second flange 32. The sealing sleeve 40 therefore has a U-shaped section.

[0056] According to a preferred embodiment, the sealing sleeve 40 may be formed by stamping a sheet metal, preferably metal. The junction between the longitudinal wall 41 and each of the first side wall 43 and the second wall 44 may be formed by a fold line.

[0057] Remarkably, as shown in [Fig. 5], the longitudinal wall 41 of the sealing sleeve 40 is adapted to deform elastically radially inwards as shown by the arrows D during a relative movement of the first flange 31 with respect to the second flange 32 to remain applied in a sealed manner jointly on the radially external face 31c of the first flange 31 and the radially external face 32c of the second flange 32.

[0058] The relative displacement between the first flange 31 and the second flange 32 may result from a deformation of the first flange 31 and / or the second flange 32 under the effect of mechanical and / or thermal forces. As visible in [Fig. 5], the relative displacement between the first flange 31 and the second flange 32 leads to a spacing of the flanges 31, 32 relative to each other longitudinally and forms a passage 34 longitudinally between the first flange 31 and the second flange 32.

[0059] Thus, the sealing sleeve 40 makes it possible to ensure a sealed connection between the first flange 31 and the second flange 32, even if a relative movement between the first flange 31 and the second flange 32 is produced under the effect of mechanical and / or thermal forces. The sealing sleeve 40 thus makes it possible to prevent the passage of fluid, such as oil or air, longitudinally between the first flange 31 and the second flange 32 in the passage 34, in particular radially from the inside to the outside.

[0060] In an undeformed configuration of the sealing sleeve, the longitudinal wall 41 may extend in the longitudinal direction X, and the first side wall 43 and the second side wall 44 extend in the radial direction. In a deformed configuration, the longitudinal wall 41 of the sealing sleeve 40 may have a radially inward bending and the first side wall 43 and the second side wall 44 may be inclined relative to a radial plane, i.e. normal to the longitudinal axis XI, to remain applied in a sealed manner to the corresponding flange.

[0061] The assembly further comprises an annular sealing member 42 received in part in a first groove 33 defined by the first flange 31 and the second flange 32 so as to prevent fluid from passing longitudinally between the first flange 31 and the second flange 32. The first groove 33 is formed in part by the first flange 31 and the second flange 32. The sealing member 42 is received by complementary shape in the first groove 33, in this case the sealing member has, in section, a tip shape oriented radially inwards. The elastic deformation of the longitudinal wall 41 of the sealing sleeve 40 makes it possible to maintain the sealing member 42 in the first groove 33.The sealing member 42 is thus held in the first groove 33 by the fact that the longitudinal wall 41 of the sealing sleeve 40 can deform radially inwards, preventing its withdrawal from the first groove 33 and a loss of sealing. The sealing member 42 makes it possible to improve the sealing between the first flange 31 and the second flange 32.

[0062] According to the first embodiment, the sealing member 42 is a relief integral with the sealing sleeve 40 and projecting radially inward from the longitudinal wall 41 of the sealing sleeve 40. This makes it possible to avoid relative movement between the sealing sleeve 40 and the sealing member 42 which could affect the seal. The sealing sleeve 40 and the sealing member 42 may be made of a metallic material. Such a sealing member 42 is particularly suitable for a hot environment.

[0063] To facilitate the deformation of the longitudinal wall 41 radially inwards, the longitudinal wall 41 of the sealing sleeve 40 comprises a radially external face 41a which is, in section, curved concavely radially outwards.

[0064] The sealing sleeve also comprises for this purpose, a first annular notch 45a formed at the junction between the longitudinal wall 41 and the first side wall 43 and a second annular notch 45b formed at the junction between the longitudinal wall 41 and the second side wall 44. Each notch is formed here at an internal face of the sealing sleeve, the latter being defined by a face 43b of the first side wall 43 applied against the first face 31a of the first flange 31, a radially internal face 41b of the longitudinal wall 41 and a face 44a of the second side wall 44 applied against the second face 32b of the second flange 32. The notches 45a, 45b also provide mechanical flexibility to the sealing sleeve 40 at the junction between the longitudinal wall 41 and each of the first side wall 43 and the second side wall 44.Whereby, the first side wall 43 and the second side wall 44 can be oriented relative to the longitudinal wall 41 to remain applied in a sealed manner respectively on the first face 31a of the first flange 31 and the second face 32b of the second flange 32. Each notch can be, in section, of rounded shape. Thus, the annular edge connecting the longitudinal wall 41 and the first side wall 43 can open into a first annular housing formed by the first notch 45a. Similarly, the annular edge connecting the longitudinal wall 41 and the second side wall 44 can open into a second annular housing formed by the second notch 45b.

[0065] According to the first embodiment, the assembly comprises first clamping means 50. The first clamping means are configured to connect the sealing sleeve 40 to the first flange 31 and to the second flange 32 and to longitudinally clamp the first flange 31 and the second flange 32 together. This makes it possible to share the clamping means for the flanges 31, 32 and the sealing sleeve 40, to reduce the mass of the assembly 30.

[0066] The first clamping means 50 comprise an annular row of bolts. A screw 51 of each bolt passes longitudinally through the first side wall 43 of the sealing sleeve 40, the first flange 31, the second flange 32 and the second side wall 44 of the sealing sleeve 40. The head 52 of the screw 51 of each bolt bears longitudinally on a face 43a of the first side wall 43 longitudinally opposite the first flange 31 and a nut 53 of each bolt is screwed onto the screw 51 to bear longitudinally on a face 44b of the second side wall 44 longitudinally opposite the second flange 32.

[0067] Reference is now made to [Fig. 6] which represents a second embodiment of a sealed connection between the first flange 31 and the second flange 32.

[0068] The second embodiment differs from the first embodiment in that the sealing member 42 is an annular seal around the longitudinal axis XI, here toric, which is adapted to be constrained, or even compressed, in the first groove 33 by the support of the longitudinal wall 41 of the sealing sleeve 40 deforming radially inwards. Such a solution further improves the seal. In this case, the sealing member is structurally separate, i.e. distinct, from the sealing sleeve. The sealing member 42 may be made of elastomer. Such a sealing member 42 is particularly suitable for a cold environment. In this respect, the radially internal face 41b of the longitudinal wall 41 of the sealing sleeve 40 comprises a second annular groove 46 around the longitudinal axis XI in which the annular seal is partly received.

[0069] The second embodiment also differs from the first embodiment in that the assembly 30 comprises first sealing means 71 inserted longitudinally between the first side wall 43 of the sealing sleeve 40 and the first face 31a of the first flange 31 and second sealing means 72 inserted longitudinally between the second face 32b of the second flange 32 and the second side wall 44 of the sealing sleeve 40. This makes it possible to further improve the sealing of the assembly 30. The first sealing means 71 and the second sealing means 72 here each comprise an annular row of O-rings. Each O-ring of the first sealing means 71 and the second sealing means 72 is arranged around a screw 51 of one of the bolts of the first clamping means 50.

[0070] Reference is now made to [Fig.7] which represents a third embodiment of a sealed connection between the first flange 31 and the second flange 32.

[0071] The third embodiment differs from the second embodiment in that the assembly 30 comprises second clamping means 60 distinct from the first clamping means 50 and configured to longitudinally clamp the flanges together. The second clamping means 60 comprise an annular row of bolts. A screw 61 of each bolt passes longitudinally through the first flange 31 and the second at a portion of the first flange 31 and the second flange 32 located radially inward relative to the sealing sleeve 40. In other words, the screw 61 of each bolt of the second clamping means 60 does not pass through the first side wall 43 and the second side wall 44 of the sealing sleeve 40.The head 62 of the screw 61 of each bolt of the second clamping means 60 bears longitudinally on the first face 31a of the first flange 31 and a nut 63 of each bolt of the second clamping means 60 is screwed onto the screw 61 to bear longitudinally on the second face 32b of the second flange 32. The second clamping means 60 may have a tightening, or a tightening torque, in the longitudinal direction X greater than that of the first clamping means. tightening 50.

Claims

Claims

1. Assembly (30) for a turbomachine with a longitudinal axis (XI), the assembly (30) comprising at least a first element comprising a first annular flange (31) around the longitudinal axis (XI) and a second element comprising a second annular flange (32) around the longitudinal axis (XI), the first flange (31) and the second flange (32) each comprising at least a first face (31a, 32a) and a second face (31b, 32b) opposite each other in the longitudinal direction (X), the second face (31b) of the first flange (31) being applied to the first face (32a) of the second flange (32) in the longitudinal direction (X), the assembly (30) comprising an annular sealing sleeve (40) covering a peripheral portion of the first flange (31) and of the second flange (32),the sealing sleeve (40) comprising an annular longitudinal wall (41) applied radially inwards in a sealed manner jointly on a radially external face (31c) of the first flange (31) and a radially external face (32c) of the second flange (32), the longitudinal wall (41) of the sealing sleeve (40) being adapted to deform elastically radially inwards during a relative movement of the first flange (31) with respect to the second flange (32) to remain applied in a sealed manner jointly on the radially external face (31c) of the first flange (31) and the radially external face (32c) of the second flange (32).,

2. Assembly (30) according to claim 1, in which the first flange (31) and the second flange (32) define a first annular groove (33) opening radially outwards, the assembly (30) comprising an annular sealing member (42) received at least in part in the first groove (33) so as to prevent a passage of fluid longitudinally between the first flange (31) and the second flange (32), and in which the elastic deformation of the longitudinal wall (41) of the sealing sleeve (40) makes it possible to maintain the sealing member (42) in the first groove (33).

3. Assembly (30) according to the preceding claim, in which the sealing member (42) is a relief formed in one piece with the sealing sleeve (40) and projecting radially towards the inside of the longitudinal wall (41) of the sealing sleeve (40).

4. An assembly (30) according to claim 2, wherein the member sealing (42) is an annular seal around the longitudinal axis (XI), for example toric, distinct from the sealing sleeve and adapted to be constrained in the first groove (33).

5. An assembly (30) according to any preceding claim, wherein the longitudinal wall (41) of the sealing sleeve (40) comprises a radially outer face (41a) which is, in section, curved concavely radially outwards.

6. An assembly (30) according to any preceding claim, wherein the sealing sleeve (40) is held to the first flange (31) and the second flange (32) by first clamping means (50).

7. An assembly (30) according to any preceding claim, wherein the sealing sleeve (40) comprises a first side wall (43) extending radially inward from the longitudinal wall (41) and applied longitudinally in a sealing manner against the first face (31a) of the first flange (31) and a second side wall (44) extending radially inward from the longitudinal wall (41) and applied longitudinally in a sealing manner against the second face (32b) of the second flange (32).

8. Assembly (30) according to the preceding claim, in which the sealing sleeve (40) comprises a first annular notch (45a) formed at the junction between the longitudinal wall (41) and the first side wall (43) and a second annular notch (45b) formed at the junction between the longitudinal wall (41) and the second side wall (44).

9. An assembly (30) according to claim 7 or 8, claim 6 applying, wherein the first clamping means (50) comprise an annular row of bolts, one screw (51) of each bolt passing longitudinally through the first side wall (43) of the sealing sleeve (40), the first flange (31), the second flange (32) and the second side wall (44) of the sealing sleeve (40).

10. An assembly (30) according to any one of claims 7 to 9, the assembly (30) comprising first sealing means (71) interposed longitudinally between the first side wall (43) of the sealing sleeve (40) and the first face (31a) of the first flange (31) and / or second sealing means (72) interposed longitudinally between the second face (32b) of the second flange (32) and the second side wall (44) of the sealing sleeve (40).

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