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: Assembly for a turbomachine technical field

[0001] This 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. 1], 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 in a primary annular stream and a secondary flow in a secondary annular stream surrounding the primary annular stream. 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 located within the primary stream.

[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 to form a high-pressure unit. 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 to form a low-pressure unit, the blower 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 exposition, 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, with 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 far from the longitudinal axis XI, corresponds to a direction perpendicular to both the longitudinal and radial directions. Furthermore, unless otherwise specified, the adjectives "inner," "internal," "outer," and "external" are used with reference to a radial direction R, such that the inner / internal (i.e., radially inner / internal) part of an element is closer to the longitudinal axis XI than the outer / external (i.e., radially inner) part.radially external / external) of the same element. Finally, the relative qualifiers. "Upstream" and "downstream" are defined in relation to the normal direction of fluid flow (from upstream to downstream) in the turbomachine.

[0005] For assembling turbomachine components subjected to high pressure, such as housings 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 and / or longitudinal direction. The flanges define a housing 24 between them into 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 stresses, which can lead to a separation of the flanges 21, 22, forming a longitudinal passage 26 between the flanges, as shown in [Fig. 3]. Such a separation of the flanges 21, 22 results in the gasket 25 no longer being tightened between the flanges 21, 22, so that sealing is no longer ensured. This results in fluid leaking radially outwards through the passage 26, which can impair the performance of the turbomachine or possibly compromise its integrity. Summary

[0007] A turbomachine assembly with a longitudinal axis is proposed, the assembly comprising at least a first element including a first annular flange around the longitudinal axis and a second element including 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 each other 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 sealing manner jointly to a radially external face of the first flange and a radially external face of the second flange,The longitudinal wall of the sealing sleeve is adapted to deform elastically radially inwards during a relative displacement of the first flange with respect to the second flange, so as to remain jointly applied in a sealing manner to the radially external face of the first flange and the radially external face of the second flange.

[0008] Thus, the sealing sleeve ensures a watertight connection between the first flange and the second flange, even if relative displacement occurs between the first and second flanges due to mechanical and / or thermal stresses. The sealing sleeve prevents the passage of fluid, such as of oil or air, longitudinally between the first flange and the second flange, especially radially from the inside out.

[0009] The longitudinal wall can extend in a direction comprising at least one component along the longitudinal direction. The longitudinal wall of the sealing sleeve can be adapted to flex radially inwards. The sealing sleeve can be divided into sectors 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 stresses. The relative displacement between the first flange and the second flange may lead to a separation of the flanges from each other in the longitudinal direction and form a longitudinal gap between the first flange and the second flange, in particular at a radially internal portion of the first and second flanges.

[0011] The first flange can be an upstream flange and the second flange can be a downstream flange. In other words, the first flange can be longitudinally upstream of the second flange, conversely the second flange can 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 element received at least partially in the first groove so as to prevent fluid passage longitudinally between the first flange and the second flange. Elastic deformation of the longitudinal wall of the sealing sleeve may allow the sealing element to be held in the first groove.

[0013] The sealing element further improves the seal between the first flange and the second flange. The sealing element is held in the first groove by the fact that the longitudinal wall of the sealing sleeve can deform radially inwards, preventing its withdrawal from the first groove and a loss of seal.

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

[0015] The sealing element can be received by complementary shape in the first groove.

[0016] The sealing element can be a relief formed from the material with the sealing sleeve and projecting radially towards the inside of the longitudinal wall of the sealing sleeve.

[0017] This prevents relative movement between the sealing sleeve and the component sealing that could affect the seal. The sealing sleeve and the sealing element can be made of a metallic material. Such a sealing element is particularly suitable for hot environments.

[0018] The sealing element can be an annular seal around the longitudinal axis, for example toroidal, separate from the sealing sleeve and adapted to be constrained in the first groove.

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

[0020] The longitudinal wall of the sealing sleeve may include 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 internal face of the longitudinal wall.

[0021] The longitudinal wall of the sealing sleeve may include a radially external face which, in cross-section, is concave radially outwards. This facilitates the deformation of the longitudinal wall radially inwards.

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

[0023] The sealing sleeve may comprise a first lateral wall extending radially inwards from the longitudinal wall and applied longitudinally in a watertight manner against the first face of the first flange, and a second lateral wall extending radially inwards from the longitudinal wall and applied longitudinally in a watertight 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 cross-section.

[0025] The first lateral wall and the second lateral wall can extend in a direction comprising at least one component in the radial direction. In an undeformed configuration, the first lateral wall and the second lateral wall can 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 lateral wall and a second annular notch formed at the junction between the longitudinal wall and the second lateral wall.

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

[0028] The sealing sleeve comprises an inner face consisting of a face of the first lateral wall applied against the first face of the first flange, a radially internal face of the longitudinal wall, and a face of the second lateral wall applied against the second face of the second flange. Each notch can be formed on the inner face of the sealing sleeve. In other words, each notch can open onto the inner face of the sealing sleeve. The annular edge connecting the longitudinal wall and the first lateral wall can open into a first annular recess. The annular edge connecting the longitudinal wall and the second lateral wall can open into a second annular recess.

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

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

[0031] The first clamping means may include 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 can bear longitudinally on a face of the first side wall longitudinally opposite the first flange and a nut of each bolt can 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 pressed against the first face of the second flange. This makes it possible to share the clamping means for the flanges and the sealing sleeve, thereby reducing the overall mass.

[0034] According to a second possibility, the assembly may include second clamping means distinct from the first clamping means and configured to longitudinally clamp the flanges together. The second clamping means may include 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 and second flanges located radially inside relative to the sealing sleeve. In other words, the screw of each bolt of the second clamping means does not pass through the first and second side walls 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 can bear longitudinally on the first face of the first flange, and a nut of each bolt of the second clamping means can be screwed onto the screw and bear longitudinally on the second face of the second flange. The second clamping means can have a clamping force, or tightening torque, in the longitudinal direction greater than that of the first clamping means.

[0035] The assembly may include 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 further improves the sealing of the assembly.

[0036] The first sealing means may comprise an annular row of seals, preferably O-rings, each 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 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 can be an upstream disk of a turbine or compressor rotor assembly and the second element can be a downstream disk of the turbine or compressor rotor assembly.

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

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

[0041] Other features, details and advantages will become apparent from reading the detailed description below, and from analyzing the accompanying drawings, on which:

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

[0043] [Fig.2] shows a cross-sectional view of a flanged watertight connection according to the state of the known technique.

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

[0045] [Fig.4] shows a cross-sectional view of a set of flanges equipped with an element sealing according to a first embodiment of the present description.

[0046] [Fig. 5] shows a cross-sectional view of the flange assembly equipped 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 cross-sectional view of The flange assembly equipped with the sealing element according to a second embodiment of this description. Figure 6b shows a cross-sectional view of the flange assembly equipped with the sealing element according to the second embodiment in a deformed configuration.

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

[0049] Reference is now made to Figures 3 to 7, which represent an assembly for a turbomachine with longitudinal axis XL. The assembly 30 comprises 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 XL. The first element and the second element are connected together at least via the first flange 31 and the second flange 32. To this end, the first flange 31 and the second flange 32 each comprise a first face 31a, 32a and a second face 31b, 32b opposite to each other along 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 along the longitudinal direction X. As described in more detail below, the assembly 30 comprises clamping means adapted for clamping and connecting 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 can be an upstream disk of a rotor assembly 30 of a turbine or compressor and the second element can be a downstream disk of the rotor assembly 30 of a turbine or compressor.

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

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

[0054] The first flange 31 is sealed 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, particularly radially from the inside to the outside. Figures 4 and 5 illustrate a first embodiment of the 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 inwardly in a sealing manner jointly to 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 inwardly 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 inwardly 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 cross-section.

[0056] According to a preferred embodiment, the sealing sleeve 40 can be formed by stamping a sheet, preferably metallic. The junction between the longitudinal wall 41 and each of the first lateral walls 43 and the second walls 44 can 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 displacement of the first flange 31 with respect to the second flange 32 to remain applied in a sealing 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 can result from a deformation of the first flange 31 and / or the second flange 32 under the effect of mechanical and / or thermal stresses. As shown in [Fig. 5], the relative displacement between the first flange 31 and the second flange 32 leads to a the 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 ensures a leak-proof connection between the first flange 31 and the second flange 32, even if relative displacement between the first flange 31 and the second flange 32 occurs due to mechanical and / or thermal stresses. The sealing sleeve 40 therefore prevents the passage of fluid, such as oil or air, longitudinally between the first flange 31 and the second flange 32 in the passage 34, particularly radially from the inside to the outside.

[0060] In an undeformed configuration of the sealing sleeve, the longitudinal wall 41 can extend along the longitudinal direction X, and the first lateral wall 43 and the second lateral wall 44 extend along the radial direction. In a deformed configuration, the longitudinal wall 41 of the sealing sleeve 40 can exhibit radial inward deflection, and the first lateral wall 43 and the second lateral wall 44 can be inclined with respect to a radial plane, i.e., normal to the longitudinal axis XI, to remain in a tight seal against the corresponding flange.

[0061] The assembly further comprises an annular sealing element 42 partially received in a first groove 33 defined by the first flange 31 and the second flange 32 so as to prevent longitudinal fluid passage between the first flange 31 and the second flange 32. The first groove 33 is formed partially by the first flange 31 and the second flange 32. The sealing element 42 is received by complementary shape in the first groove 33; in this case, the sealing element has, in cross-section, a pointed shape oriented radially inwards. The elastic deformation of the longitudinal wall 41 of the sealing sleeve 40 allows the sealing element 42 to be held in the first groove 33.The sealing element 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 element 42 improves the seal between the first flange 31 and the second flange 32.

[0062] According to the first embodiment, the sealing element 42 is a raised section formed from the material of the sealing sleeve 40 and projecting radially inwards towards the longitudinal wall 41 of the sealing sleeve 40. This prevents relative movement between the sealing sleeve 40 and the sealing element 42 that could affect the seal. The sealing sleeve 40 and the sealing element 42 can be made of a metallic material. Such a sealing element 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 includes a radially external face 41a which is, in section, curved concave radially outwards.

[0064] The sealing sleeve also includes, for this purpose, a first annular notch 45a formed at the junction between the longitudinal wall 41 and the first lateral wall 43, and a second annular notch 45b formed at the junction between the longitudinal wall 41 and the second lateral wall 44. Each notch is formed on an internal face of the sealing sleeve, this being defined by a face 43b of the first lateral wall 43 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 lateral wall 44 against the second face 32b of the second flange 32. The notches 45a and 45b also provide mechanical flexibility to the sealing sleeve 40 at the junction between the longitudinal wall 41 and each of the first and second lateral walls 43. 44.Whereby the first lateral wall 43 and the second lateral wall 44 can be oriented relative to the longitudinal wall 41 to remain sealed against the first face 31a of the first flange 31 and the second face 32b of the second flange 32, respectively. Each notch can be rounded in cross-section. Thus, the annular edge connecting the longitudinal wall 41 and the first lateral wall 43 can open into a first annular recess formed by the first notch 45a. Similarly, the annular edge connecting the longitudinal wall 41 and the second lateral wall 44 can open into a second annular recess 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 the second flange 32 and to longitudinally clamp the first flange 31 and the second flange 32 together. This allows the clamping means for the flanges 31, 32 and the sealing sleeve 40 to be shared, thereby reducing 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 against 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 against 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 watertight connection between the first flange 31 and the second flange 32.

[0068] The second embodiment differs from the first embodiment in that The sealing element 42 is an annular seal around the longitudinal axis XI, here toroidal, which is adapted to be constrained, or compressed, in the first groove 33 by the support of the longitudinal wall 41 of the sealing sleeve 40, which deforms radially inwards. This solution further improves the seal. In this case, the sealing element is structurally separate, i.e., distinct from the sealing sleeve. The sealing element 42 can be made of elastomer. Such a sealing element 42 is particularly suitable for cold environments. In this respect, the radially inner face 41b of the longitudinal wall 41 of the sealing sleeve 40 includes a second annular groove 46 around the longitudinal axis XI, in which the annular seal is partially received.

[0069] The second embodiment also differs from the first embodiment in that the assembly 30 comprises 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 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. This further improves the sealing of the assembly 30. The first sealing means 71 and the second sealing means 72 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 watertight 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 flange 32 at a portion of the first flange 31 and the second flange 32 located radially inside 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 clamping force, or a tightening torque, in the longitudinal direction X greater than that of the first 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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