Hydrostatic ring seal

Abstract

The invention relates to a seal (100) for an aircraft turbomachine, comprising a plurality of seal sectors distributed circumferentially about a longitudinal axis (X), each seal sector (102a, 102b) comprising a radially outer annular wall sector (106a, 106b) and a radially inner annular wall sector (110a, 110b), which are connected to each other by an elastically deformable member (105a, 105b), wherein the circumferentially adjacent pairs of seal sectors (102a, 102b) have their respective elastically deformable members formed monolithically as a common deformable elastic member (105), the common deformable elastic member (105) connecting together two radially inner annular wall sectors (110a, 110b) of circumferentially adjacent seal sectors, and wherein the radially outer annular wall sectors (106a, 106b) of the seal sectors form a monolithic outer shroud.

Description

[0001] Description

[0002] Title: Hydrostatic ring seal

[0003] Technical field

[0004] [1] The present disclosure relates to an annular seal, such as a hydrostatic annular seal. The present document also relates to an assembly comprising such a seal as well as a turbine or a turbomachine comprising such a seal.

[0005] Prior art

[0006] [2] Figure 1 schematically represents a turbomachine 1 with a double flow of longitudinal axis X. The turbomachine 1 generally comprises, from upstream AM to downstream AV according to the direction of flow of the gases within the turbomachine 1, a fan 2, a low-pressure compressor 3, a high-pressure compressor 4, a combustion chamber 5, a high-pressure turbine 6, a low-pressure turbine 7 and an exhaust system downstream of the turbomachine 1. The gas flow, in particular air, entering upstream of the turbomachine 1 first circulates through the fan 2 then divides, on the one hand, into an annular circulation vein called the primary vein 8, and on the other hand, into an annular circulation vein called the secondary vein 9 surrounding the primary vein 8. The low-pressure compressor 3, the high-pressure compressor 4, the combustion chamber 5, the high-pressure turbine 6 and the low-pressure turbine 7 are arranged in the primary vein 8.

[0007] [3] In this document, the terms "longitudinal", "radial" and "circumferential" are defined relative to the longitudinal axis X of the turbomachine 1, the longitudinal axis X being the same as the axis of rotation of the low-pressure and high-pressure rotors of the turbomachine 1. The terms "inner" and "outer", as well as "internal" and "external", are then defined in the radial direction relative to the longitudinal axis X. The terms, upstream and downstream are defined relative to the general direction of flow of the gases in the turbomachine along the longitudinal axis X around which the turbomachine extends.

[0008] [4] Reference is now made to Figure 2A schematically showing a partial view of a low-pressure turbine 7 with a longitudinal axis which comprises an alternation of annular rows of moving blades 9 arranged longitudinally in alternation with annular rows of stator blades 10. In Figure 2, only two annular rows of rotor blades 9 and one annular row of stator blades 10 are shown. The annular rows of rotor blades 9 or moving blades 9 are connected to each other by a cylindrical shell 11.

[0009] [5] Each of the annular rows of stator blades 10 comprises a radially inner annular platform 12 and a radially outer annular platform (not shown) between which a plurality of blades 13 extend. The radially outer annular platform is fixed to a casing of the turbine.

[0010] [6] Managing the seal between the end of the stator blades 10 and the shell 11 of the rotor is important to limit gas leaks between the rotor and the stator 10 and to control the pressure and temperature conditions on either side of said seal and also radially below the seal. To this end, it is known to provide a radial annular partition 14 extending from said radially internal annular platform inwards, and carrying at one end a sealing member 15 intended to maintain in operation a small clearance with the corresponding shell of the rotor.

[0011] [7] To this end and as shown in Figures 2A and 2B, the annular row of stator blades 10 carries an annular clearance control seal 15 arranged radially inside the annular row of stator blades 10 and radially outside the cylindrical shell 11, the annular clearance control seal 22 cooperating in a contactless seal with the cylindrical shell 11 in order to limit the circulation from upstream of the annular row of stator blades 10 to downstream in the annular space between the seal 15 and the cylindrical shell 11.

[0012] [8] In particular, such a clearance control seal 15 operates with a low and controlled annular clearance between the latter and the shell 11 when the turbine is in operation. Furthermore, this type of seal aims to achieve an adaptation of the clearance in operation. The use of the hydrostatic seal 15 then offers the advantage of limiting the leakage flow at the level of the seal, and thus makes it possible to improve the performance of the turbomachine and to reduce the requirements in terms of thermal and mechanical stresses when sizing the various components of the turbine 7.

[0013] [9] As shown in Figure 2B, the hydrostatic annular seal 15 may be formed of two concentric annular walls 16, 17, and a plurality of elastically deformable members arranged circumferentially next to each other and extending between the two walls 16, 17 and including in particular elastically deformable blades 18 extending circumferentially. For example, document WO 2009 / 148787 describes such a seal. This configuration makes it possible to improve the control of the radial deformation of the seal 15, and therefore the control of the clearance between the seal 15 and the ferrule 11 cooperating with the sealing seal 15 so as to limit the passage of air.

[0010] In operation, the flexible blades must have a sufficient width to counter the torsional forces resulting from the normal operation of a hydrostatic seal.However, the lamellas must remain sufficiently flexible to allow radial displacement of the pads under the effect of radial hydrostatic pressure forces, so that low lamellar thicknesses are sought. However, manufacturing thin lamellas is difficult due to significant variability. Thus, it is necessary to maintain a minimum thickness at the expense of flexibility, which can be increased by increasing the circumferential length of the lamellas. However, this leads to an increase in the circumferential extent of each pad and therefore to a reduction in the ability of the seal to adapt to the clearances at each location around the turbine rotor.

[0014]

[0011] This document aims to provide a simple, reliable and economical solution to the aforementioned problem.

[0015] Summary

[0016]

[0012] There is thus proposed a seal for an aircraft turbomachine comprising a plurality of seal sectors distributed circumferentially around a longitudinal axis, each seal sector comprising a radially outer annular wall sector and a radially inner annular wall sector connected to each other by an elastically deformable member, in which the circumferentially adjacent pairwise seal sectors have their respective elastically deformable member produced monolithically in a common deformable elastic member, the common deformable elastic member connecting together two circumferentially adjacent radially inner annular wall sectors of the seal sector and in which the radially outer annular wall sectors of the seal sectors form a monolithic outer shell.

[0017]

[0013] According to the invention, the elastic means of each elastic member are shared with two circumferentially adjacent pads, which makes it possible to reduce the mass of the hydrostatic annular seal.

[0018]

[0014] The common elastically deformable member may have a first circumferential end radial tab connected to a circumferential end of the inner annular wall sector of a first seal sector and a second circumferential end radial tab connected to a circumferential end of the inner annular wall sector of a second seal sector, each circumferential end radial tab being connected to a common radial tab by a first blade and a second blade which each extend circumferentially to connect each circumferential end radial tab to a common radial tab.

[0019]

[0015] Compared to the prior art, it is thus possible to eliminate a radial lug, which makes it possible to lighten the seal. This results in a significant bulk grain in the circumferential direction. With constant stiffness compared to the prior art, it is thus possible to use a greater blade thickness, thus limiting torsion. As indicated previously, an increased thickness makes it possible to control the variability in thickness between the blades and therefore to better control torsion.

[0020]

[0016] Said at least first blade and / or said at least one second elastic blade may comprise at least two blades spaced radially from one another.

[0021]

[0017] Said at least two blades may be substantially parallel.

[0022]

[0018] The common radial leg may define a plane of symmetry for the common elastically deformable member.

[0023]

[0019] The circumferential end radial tabs of the seal sectors may each be integral with a circumferential end of a seal sector.

[0024]

[0020] The common deformable elastic member may comprise three radial legs, the common deformable elastic member has a common radial leg arranged circumferentially at the junction between the radially external annular wall sectors to achieve the two-by-two junction of the radially internal annular wall sectors of the joint sector.

[0025]

[0021] The present document relates to an assembly for an aircraft turbomachine with a longitudinal axis comprising a distributor which has a crown of stator blades comprising a root at the radially internal end of the distributor carrying a seal as described above, the seal being intended to cooperate in a contactless seal with a cylindrical shell of a rotor of the turbomachine arranged radially under the distributor.

[0026]

[0022] Also concerned is a turbine for an aircraft turbomachine, the turbine comprising a casing, an assembly as described in the preceding paragraph and a rotor which comprises a cylindrical shroud driven in rotation about the longitudinal axis and, the distributor being mounted in the casing and the cylindrical shroud being arranged radially under the distributor.

[0027]

[0023] Finally, the present document also relates to a turbomachine, such as an aircraft turbojet or turboprop, comprising an assembly or a turbine. Brief description of the drawings

[0028]

[0024] Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the attached drawings, in which:

[0029]

[0025] [Fig. 1] schematically illustrates a sectional view of an example of a turbomachine;

[0030]

[0026] [Fig. 2] schematically illustrates a partial view of a part of a turbine, for example low pressure, Figure 2B being an enlargement of the seal illustrated in Figure 2A;

[0031]

[0027] [Fig.3] schematically illustrates an annular sealing gasket;

[0032]

[0028] [Fig. 4] schematically illustrates a portion of an annular row of stator blades and a seal according to the present document;

[0033]

[0029] [Fig. 5] is an enlarged view of the seal of Fig. 4;

[0034]

[0030] [Fig. 6] and [Fig. 7] schematically illustrate the sealing principle of the seal according to this document;

[0035]

[0031] [Fig. 8] schematically illustrates a first seal according to the present document;

[0036]

[0032] [Fig. 9] schematically illustrates a second seal according to the present document;

[0037]

[0033] [Fig. 10] to [Fig. 16] schematically illustrate a third type of seal according to the present document as well as variants thereof;

[0038]

[0034] [Fig. 17] to [Fig. 20] schematically illustrate alternative embodiments of the connecting tabs between a radially external annular wall and the radially internal annular walls for a sealing joint;

[0039]

[0035] [Fig. 21] is a three-dimensional schematic view of a sector of an annular row of stator or distributor blades according to the present document;

[0040]

[0036] [Fig. 22] is a schematic perspective view of part of a hydrostatic annular seal;

[0041]

[0037] [Fig. 23] is a schematic perspective view of the legs of a hydrostatic annular seal;

[0042]

[0038] [Fig. 24] and [Fig. 25] are schematic perspective views of the radial sliding means between the hydrostatic annular seal and the annular row of stator blades;

[0039] [Fig. 26] is a sectional view of an assembly according to the present document;

[0043]

[0040] [Fig. 27] to [Fig. 33] are schematic perspective views of an assembly comprising a hydrostatic annular seal according to the present document;

[0044]

[0041] [Fig. 34] and [Fig. 35] including schematic perspective views of an assembly according to the present document and comprising a hydrostatic annular seal connected by form cooperation with radial sliding connection means on an annular row of stator blades;

[0045]

[0042] [Fig. 36] is a schematic perspective view of a circumferential edge of an annular seal as described herein;

[0046]

[0043] [Fig. 37] is a schematic illustration of an annular seal according to the present document, the annular seal having a housing on its radially inner face;

[0047]

[0044] [Fig. 38] schematically illustrates a partial view of an example of an assembly according to the present document, this assembly comprising an annular seal;

[0048]

[0045] [Fig. 39] schematically illustrates an enlarged partial view of an example assembly according to Figure 38;

[0049]

[0046] [Fig. 40] schematically illustrates an enlarged partial view of another example of an assembly according to Figure 38;

[0050]

[0047] [Fig. 41] schematically illustrates respectively a partial view of an example assembly according to the present document, and two enlarged partial views of the example assembly in two different configurations;

[0051]

[0048] [Fig. 42] schematically illustrates a partial view of an example of a hydrostatic annular seal;

[0052]

[0049] [Fig. 43] schematically illustrates a partial sectional view of an example assembly according to the present document;

[0053]

[0050] [Fig. 44] schematically illustrates a partial sectional view of another example of an assembly according to the present document;

[0054]

[0051] [Fig. 45] schematically illustrates a partial sectional view of another example of an assembly according to the present document;

[0055]

[0052] [Fig. 46] schematically illustrates a partial sectional view of another example of an assembly according to the present document. Description of the embodiments

[0056]

[0053] The present document relates to an annular sealing joint such as a hydrostatic annular sealing joint used in a turbomachine. It comprises in particular different embodiments and integration forms of such a hydrostatic annular sealing joint.

[0057]

[0054] Reference is made to Figure 3 schematically showing a partial view of a hydrostatic annular seal 51 according to the present document. Preferably, this hydrostatic annular seal 51 is integrated into an assembly 52 for a turbomachine with a longitudinal axis X. Such an assembly is implemented in a turbine, in particular a low-pressure turbine, of a turbomachine. The present document also relates to any type of turbomachine comprising such a turbine, for example a turboprop or a turbojet for aircraft.

[0058]

[0055] The assembly 52 comprises a cylindrical shell 53 intended to be driven in rotation about the longitudinal axis X and an annular row of stator blades. The assembly may also comprise two annular rows of moving blades arranged longitudinally on either side of the annular row of stator blades 54 and connected to each other by the cylindrical shell 53. The annular row of stator blades 54 carries the hydrostatic annular seal 51. This hydrostatic annular seal 51 is arranged radially inside the annular row of stator blades 54 and radially outside the cylindrical shell 53, the hydrostatic annular seal 51 cooperating in a contactless sealing manner with the cylindrical shell 53.

[0059]

[0056] The hydrostatic annular seal 51 preferably comprises a radially outer annular wall 55, a radially inner annular wall 56 and a plurality of elastically deformable members or elements 57, in particular distributed circumferentially around the longitudinal axis X. The hydrostatic annular seal 51 can deform radially thanks to the flexibility offered by the elastically deformable member 57 connecting together the radially inner annular wall 56 and the radially outer annular wall 55. The radially inner 56 and outer 55 annular walls and the elastically deformable element 57 are in particular dimensioned to control the radial deformation of the hydrostatic annular seal 51, and therefore control a clearance J2 between the hydrostatic annular seal 51 and the cylindrical shell 53.

[0060]

[0057] The seal may comprise a plurality of seal sectors distributed circumferentially around the longitudinal axis, each seal sector comprising a radially inner annular wall sector 56 and a radially outer annular wall sector 55 connected to each other by an elastically deformable member 57. The radially outer annular wall sectors may form a monolithic outer shell, i.e. a single piece, and the radially inner annular wall sectors are distinct and arranged circumferentially end to end.

[0061]

[0058] A turbine is a system that expands air, starting from a high pressure upstream to a low pressure downstream. It is necessary that there is a maximum of air which passes through the turbine and which does not escape from the vein. A layer of air coming from the annular cavity located upstream of the seal 51 passes between the cylindrical shell 53 and the seal 51 whose differences in radial dimensions form the clearance J2. By maintaining a small radial clearance, the hydrostatic annular seal 51 thus provides a seal. It is the pressure differential between the annular cavity upstream of the hydrostatic annular seal 51 and the annular cavity immediately downstream of this hydrostatic annular seal 51 which controls the resultant of the radial pressure forces applied to the radially internal annular wall 56 of the hydrostatic seal 51.

[0062]

[0059] The hydrostatic annular seal 51 comprises an internal surface 59 arranged radially opposite the cylindrical shell 53. This internal surface 59 comprises a first substantially cylindrical surface portion 60, a second concave curved surface portion 61 with a concavity curved radially outwards so as to form an annular cavity opposite the cylindrical shell 53, a third substantially cylindrical surface portion 62 and a fourth frustoconical surface portion 63 with a section increasing downstream. There is a clearance j1 between the first surface portion 60 and the cylindrical shell 53, and a clearance j2 between the third surface portion 62 and the cylindrical shell 53. The clearances j1 and j2 are such that the clearance j1 is greater than j2. This difference in clearances between j1 and j2 generates a restriction. This restriction allows the air to accelerate and causes static pressure to be lost in the event of high j1 clearance (>0.6mm for example).The hydrostatic annular seal 51 deforms under the resultant of the mechanical forces exerted on the internal surface 59 and the external surface 63 of the sectored pad 58. This specific configuration makes it possible to maintain a low clearance and therefore an efficient seal, without risking contact between the sectored pad 58 and the ferrule 53.

[0063]

[0060] The annular row of stator blades 54 comprises a radial annular partition 64 carrying the hydrostatic annular seal 51. The hydrostatic annular seal 51 may comprise radial sliding means 65 in the direction of the annular row of stator blades 54. The radially external annular wall 55 is connected to an annular part 71 comprising an upstream annular tab 66 and a downstream annular tab 67 each comprising longitudinally facing orifices 68 in which pins 69 are mounted. The external annular wall 55 and the annular part 71 may be formed in a single piece. The pins 69 are mounted shrink-fitted in the orifices 68 of one of the upstream 66 and downstream 67 annular tabs only so as to allow insertion into the other of the upstream 66 and downstream 67 annular tabs. Preferably, the shrink-fitting is carried out on the upstream annular tab 66.The radial annular partition 64 of the annular row of stator blades 54 comprises a plurality of preferably oblong openings 70 in which an intermediate part of the pins 69 are mounted. Alternatively, the openings may be rectangular. This assembly allows a degree of freedom in the radial direction of the hydrostatic annular seal 51 relative to the annular row of stator blades 54. Other means of radial displacement could be envisaged. The radial sliding of the hydrostatic annular seal 51 can be carried out as in Figures 21 to 26, but also as in Figures 27 to 33.

[0064]

[0061] Thus, a degree of freedom in the radial direction is left to the hydrostatic annular seal 51 when the turbomachine is in operation. Indeed, under the effect of heat, expansions of the annular row of stator blades 54 opposite the annular part 71 occur. The U-shape produced by the connection between the upstream annular tab 66 and the downstream annular tab 67 makes it easier to mount and guide the seal radially by sliding on the annular partition 64. This U-shape therefore expands radially under the effect of expansion and this U-shape guarantees that there will be no thrust radially outwards. Thus, the hydrostatic annular seal 51 is guided and undergoes little deformation by temperature differential with the adjacent / neighboring components both in the radial direction, and in the circumferential or even longitudinal direction.

[0065]

[0062] In order for there to be the pressure differential described above between the upstream cavity and the downstream cavity of the turbine, it is necessary to provide a secondary seal 72. This secondary seal 72 prevents there from being a leak between the radially internal annular wall 56 and the radially external annular wall 55 and that the air passes only between the cylindrical shell 53 and the sectors of the radially internal annular wall 56.

[0066]

[0063] For this purpose, reference is now made to Figures 4 to 7.

[0067]

[0064] Figures 4 and 5 show the hydrostatic annular seal 51 provided with the secondary seal 72 and fixed to the annular row of stator blades 54. This hydrostatic annular seal 51 is intended to be arranged longitudinally between two annular rows of rotor blades 73 arranged on either side of an annular row of stator blades 54. As described previously, the hydrostatic annular seal 51 comprises a radially inner annular wall 56, a radially outer annular wall 55 connected to each other by the elastically deformable members 57. An annular flange is arranged opposite the upstream faces 74 of the elastically deformable members 57. This flange is carried by the radially outer annular wall 55. There is an annular clearance between a radially inner end 76 of the ring 75 and the wall radially internal annular 56.This annular clearance is sealed by the secondary seal 72 which we will describe in more detail.

[0068]

[0065] As illustrated in Figures 4 to 6, a first annular row of first sheet metal sectors 77 is arranged circumferentially end to end and applied to an upstream face 78 of the ring 75. A second annular row of second sheet metal sectors 79 is applied to upstream faces 80 of the first annular row of first sheet metal sectors 77. The sheet metal sectors 77, 79 have a thickness of between 0.1 and 0.6 mm. The second sheet metal sectors 79 may be arranged circumferentially by being offset relative to the first sheet metal sectors 77 so that a second sheet metal sector 79 is arranged longitudinally opposite two circumferentially adjacent first sheet metal sectors. The internal edges 81 of the second sheet metal sectors 79 are aligned longitudinally with the internal edges 82 of the first sheet metal sectors 77.The outer edges 83 of the second sheet metal sectors 79 are longitudinally aligned with the outer edges 84 of the first sheet metal sectors 77. The circumferential edges 85, 86 of the first sheet metal sectors 77 are misaligned with the circumferential edges 87, 88 of the second sheet metal sectors 79. The misalignment of the circumferential edges 85, 86, 87, 88 of the first 77 and second 79 sheet metal sectors makes it possible to avoid leakage linked to the annular clearance.

[0069]

[0066] More specifically, as illustrated in Figure 7, the radially inner ends 89 of the first sheet metal sectors 77 bear on a radial face 90 of the radially inner annular wall 56. The flange 75 comprises an inner annular rim 91a which extends upstream. An upstream face 92 of the ring 75 is formed at the upstream end of the inner annular rim 91a of the flange 75. The first annular row of the first sheet metal sectors 77 is arranged circumferentially end to end and applied to the upstream face 92 of the ring 75. The material of the first sheet metal sectors and that of the flange is determined so as to facilitate sliding between these two parts.

[0070]

[0067] The flange 75 also comprises an annular rim 91 b extending downstream and formed at its radially outer end. As can be seen in FIG. 5, the annular rim 91 b radially covers the upstream ends of the radially outer annular wall sectors.

[0071]

[0068] As illustrated in Figures 4 to 7, the sheet metal sectors 77, 79 are fixed to the ring 75 by fixing elements 93 passing through openings 94 on the sheet metal sectors 77, 79. These fixing elements 93 fix the first 77 and second sheet metal sectors 79 together to the ring 75, itself carried by the radially external annular wall 66. The fixing elements may be pins. The openings 94 are such that there is play and the sheet metal sectors 77, 79 are able to move slightly.

[0072]

[0069] We now refer to Figure 8 which represents a hydrostatic annular seal 150 intended to provide sealing between an annular stator row to which it is connected and a cylindrical shell as described with reference to Figure 2. As illustrated in Figure 8, the annular seal 150 which is of a known type comprises an internal annular wall 151 formed of sectors 152 arranged circumferentially end to end. It also comprises an external annular wall 153 from which at least one annular tab or wall 154 can extend comprising at least one orifice 155 for the insertion of an axis preferably materialized by a pin, or by the smooth shaft of a screw, or alternatively a spacer, intended to cooperate with an oblong opening of a radial annular partition carried by the internal annular platform of the annular row of stator blades.

[0073]

[0070] Each radially internal annular wall sector 152 is connected to the external annular wall 153 by an elastically deformable member 156. Thus, each radially internal annular wall sector is associated with an elastically deformable member 156.

[0074]

[0071] Each elastically deformable member 156 comprises two elastic strips 159 extending circumferentially and parallel to each other. First ends of the strips 159 are connected to a first radial tab 158 carried by a radially inner annular wall sector and second ends of the strips 159 are connected to a second radial tab 157 carried by the radially outer annular wall 153. If this type of embodiment proves effective, it does not make it possible to achieve the best compromise between radial flexibility and torsional strength for a given thickness of strips as mentioned with reference to the prior art at the beginning of the description.

[0075]

[0072] Thus, a hydrostatic annular seal 100 is proposed formed from a plurality of circumferentially distributed sealing seal sectors, only one being shown in FIG. 9.Each seal sector 102a, 102b comprises a radially outer annular wall sector 106a, 106b and a radially inner annular wall sector 110a, 110b connected to each other by an elastically deformable member 105a, 105b, in which the circumferentially adjacent seal sectors 102a, 102b in pairs have their respective elastically deformable member 105a, 105b monolithically made of a common deformable elastic member 105, the common deformable elastic member 105 connecting together two circumferentially adjacent radially inner annular wall sectors 110a, 110b of the seal sector and in which the radially outer annular wall sectors 106a, 106b of the seal sectors form a monolithic external shell 106.

[0076]

[0073] Thus, each common elastic member 105 is elastically connected to at least two radially inner annular wall sectors 110a, 110b, here exactly two, which are circumferentially adjacent and to two sectors 106a, 106b of radially outer annular wall 106. The radially inner annular wall sectors 110a, 110b successively form the radially inner annular wall of the hydrostatic annular seal 100. In the embodiment shown in FIG. 9, each elastically deformable member 105 is connected to two circumferentially adjacent inner sectors 110a, 110b, one 110a being named as a primary sector and the other 110b being named secondary sector.

[0077]

[0074] It is observed that each common elastic member 105 comprises at least one first elastically deformable circumferential blade 112a, 112b and at least one second elastically deformable circumferential blade 114a, 114b connected by first circumferential ends facing each other to the external annular wall and of which second ends 122 circumferentially opposite one another with respect to the first ends are each connected to the primary sector 110a and to the secondary sector 110b. Said first end 116 of said at least one first blade 112a, 112b and said first end 116 of said at least one second blade 114a, 114b are arranged in circumferential screw.

[0078]

[0075] In Figure 9, it is observed that said at least one first blade 112a, 112b and said at least one second blade 114a, 114b comprise two blades which are radially spaced from one another. The first blades 112a, 112b and / or the second blades 114a, 114b may be substantially parallel to one another as shown in Figure 9. The first blades 112a, 112b and / or the second blades 114a, 114b may also form an angle between them. Among the first blades 112a, 112b, a first blade 112b is a first inner blade 112b and the other 112a is a first outer blade. Among the second blades 112a, 112b, one second blade 112b is a second inner blade and the other 112a is a second outer blade.

[0079]

[0076] The first ends 116 of the first and second elastic blades may be connected, as shown in FIG. 9, to the same first tab 118 which may extend substantially radially. The first internal blade 111b and / or the second internal blade 114b may be connected to the radially internal end of the first tab 118. The first external blade 112a and / or the second external blade 114a may be connected in the vicinity of the radially external end of the first tab 118, this radially external end of the first tab 118 being connected to the radially external annular wall.

[0080]

[0077] The radially internal end of the first leg 118 is devoid of direct connection to one of the two circumferentially adjacent primary 110a and secondary 110b sectors, the connection of the first leg 118 with the sectors 110a, 110b being achieved indirectly by the first 112a, 112b and second blades 114a, 114b and the second legs 120a, 12ab, the latter being described in the following paragraphs.

[0081]

[0078] In the embodiment of Figure 9, the legs are dimensioned so as not to be deformable, the deformation taking place at the level of the blades.

[0082]

[0079] The second ends 122 of the first and second elastic blades may be connected, as shown in FIG. 9, to a second tab 120a, 120b which may extend substantially radially. It is observed that there are two second tabs 120a, 120b which are arranged on either side circumferentially of the first tab 118 and which may be positioned circumferentially in a substantially symmetrical manner with respect to the position of the first tab 118. A second tab called the second primary tab 120a is connected to the second ends of the first blades 112a, 112b and a second tab called the second secondary tab 120b is connected to the second ends of the second blades 114a, 114b.

[0083]

[0080] According to the embodiment shown in Figure 9, the common elastically deformable member thus has a first circumferential end radial tab 120a connected to a circumferential end of the internal annular wall sector 110a of a first seal sector 102a and a second circumferential end radial tab 120b connected to a circumferential end of the internal annular wall sector 110b of a second seal sector 102b, each circumferential end radial tab 120a, 120b being connected to a common radial tab 118 by a first blade 112a, 112b and a second blade 114a, 114b which each extend circumferentially to connect each circumferential end radial tab 120a, 120b to a common radial tab 118. 18.

[0084]

[0081] The term “primary” and the term “secondary” only make it possible to distinguish between the two second legs 120a, 120b and their connection to the primary 110a and secondary 110b sectors.

[0085]

[0082] The first outer blade 112a and / or the second outer blade 114a may be connected to the radially outer end of the second primary 120a and secondary 120b legs. The first inner blade 112b and / or the second inner blade 114b may be connected in the vicinity of the radially inner end of a second leg 120a, 120b, this radially inner end of a second leg 120a, 120b being connected to a pad 110a, 110b. More precisely, the radially inner end of the second primary leg 120a is connected to the primary sector 110a and for example in the vicinity of a circumferential end thereof. The radially inner end of the second secondary leg 120b is connected to the secondary pad 110b and for example in the vicinity of a circumferential end thereof. Said two ends of the primary 110a and secondary 110b sectors are opposite their ends which are circumferentially opposite.

[0086]

[0083] Compared to Figure 8, the embodiment mentioned above makes it possible to eliminate a connecting tab for each pair of primary 110a and secondary 110b sectors, which makes it possible to lighten the structure of the hydrostatic annular seal 100. A significant gain in size is also obtained in the circumferential direction. With constant stiffness compared to the prior art, it is thus possible to use a greater blade thickness, thus limiting torsion. Thus, for each pair of primary 110a and secondary 110b sectors, it is necessary to have only three tabs instead of four as in Figure 8.

[0087]

[0084] The annular seal 100 could comprise means allowing radial sliding of the hydrostatic annular seal relative to the radial annular partition of the annular row of stator blades. These means could be, for example, of the type described with reference to FIGS. 21 to 25 or with reference to FIGS. 27 to 33.

[0088]

[0085] Reference is now made to Figures 10 to 20.

[0089]

[0086] Figures 10 to 16 schematically illustrate a third hydrostatic annular seal 201 as well as variants thereof.

[0090]

[0087] Figure 10 shows a hydrostatic annular seal 201 comprising a radially inner annular wall 202, an elastically deformable member 203 and a radially outer annular wall 204. The radially inner annular wall 202 is formed of a plurality of sectored pads 205. The sectored pad 205 shown is connected to the radially outer annular wall 204 by the elastically deformable member 203. This elastically deformable member 203 comprises an inner tab 206 and an outer tab 207. Each tab 206, 207 is substantially planar. The internal leg 206 comprises a radially internal end 208 to which said sectored pad 205 is fixed. The external leg 207 comprises a radially external end 209 to which the radially external annular wall 204 is fixed. The internal leg 206 comprises a radially external end 210 connected to a radially internal end 21 1 of the external leg 207 by a connecting wall 215.In the embodiment of Figure 10, the inner leg 206 and the outer leg 207 extend radially such that the radially inner end 211 of the outer leg 207 is arranged radially inside the radially outer end 210 of the inner leg 206.

[0091]

[0088] The hydrostatic annular seal 201 shown in FIG. 11 comprises an elastically deformable member 203 formed of several elastically deformable members. It thus comprises a first elastically deformable member 212 and a second elastically deformable member 213. The first 212 and second 213 elastically deformable members are arranged so that the internal tab 206, respectively the external tab 207, of the first member 212 is axially adjacent to the external tab 207, respectively the internal tab 206, of the second member 212.

[0092]

[0089] The hydrostatic annular seal 201 shown in Figure 12 comprises an elastically deformable member 203 formed of three elastically deformable members, a first member 212, a second member 213 and a third member 214. The first 212 and second 213 members are arranged so that the inner tab 206, respectively the outer tab 207, of the first member 212 is axially adjacent to the outer tab 207, respectively the inner tab 206, of the second member 213. The third member 214 is arranged so that its outer tab 207, respectively its inner tab 206, is axially adjacent to the inner tab 206, respectively the outer tab 207, of the second member 212.

[0093]

[0090] The outer tab 207 may be inclined relative to a tangent to the radially outer annular wall 204 at the connection point between the outer tab 207 and the radially outer annular wall 204. Similarly, the inner tab 206 may be inclined relative to a tangent to the radially inner annular wall 202 at the connection point between the inner tab 206 and the radially inner annular wall 202. This angle may be between 10° and 150°. It is thus understood that the inner tab 206 and the outer tab 207 may have different inclinations as clearly appears in FIG. 13. Other embodiments are of course possible. The inclination of the tabs 207, 206 relative to the radial direction makes it possible to restrict the movement of the elastically deformable member in the longitudinal direction.

[0094]

[0091] Each connecting wall 215 may comprise a thickness, defined by the radial dimension of the connecting wall 215, of between 0.5 and 10 mm and / or a width, defined by the longitudinal dimension of the connecting wall 215, of between 2 and 30 mm.

[0095]

[0092] Each tab 206, 207 may comprise at least one of the following parameters: - A width in the longitudinal direction of between 2 and 30 mm,

[0096] A dimension according to its direction of extension between its radially internal and external ends between 3 and 60 mm,

[0097] - A dimension perpendicular to the direction of extension of the leg between 0.5 and 10 mm.

[0098]

[0093] As illustrated in Figure 14, the hydrostatic annular seal 201 comprises first 212 and second 213 members. The connecting wall 215 makes it possible to restrict the upstream / downstream tilting movements due to its resistance to torsion. The internal and external tabs 206, 207 which are also deformable allow a predominantly radial movement by bending of the elastically deformable member. The inclination of the tabs 206 and 207 relative to the internal 202 and external 204 annular wall makes it possible to limit the displacement of the pad 205 along the longitudinal axis.

[0099]

[0094] As illustrated in Figure 15, the hydrostatic annular seal 201 may comprise a first 212 and a second 213 elastically deformable members. The connecting wall 215 of the first member 212 comprises a radially internal surface formed successively by a concave surface 216 then a convex surface 217. The connecting wall 215 of the second member 213 comprises a radially internal surface formed successively by a convex surface 217 then a concave surface 216.

[0100]

[0095] The hydrostatic annular seal 201 shown in Figure 16 comprises an elastically deformable member 203 comprising a first 212 and a second 213 member. The connection between the radially outer end 210 of the inner tab 206 and the connecting wall 215 of each member is at a right angle. Similarly, the connection between the radially inner end 211 of the outer tab 207 and the connecting wall 215 of each member is also at a right angle. Figure 16 illustrates the oblique inclination of the members 212, 213.

[0101]

[0096] Figures 17 to 20 schematically illustrate alternative embodiments of the connecting tabs of the connecting walls 215 to the radially inner 202 and outer 204 annular walls for a hydrostatic annular seal 201. Only one outer tab 207 is illustrated but the description also applies to an inner tab 206.

[0102]

[0097] Figure 17 shows a tab 207 with a substantially constant section between its internal and external ends.

[0103]

[0098] Figure 18 illustrates a tab 207 with a section which evolves radially and which increases in the particular case of Figure 18. The general shape is here triangular.

[0099] Figure 19 represents a tab 207 comprising a circumferential surface oriented towards the other tab which is concave and an opposite circumferential surface which is substantially planar.

[0104]

[0100] Figure 20 also shows a tab 207 having concave and planar circumferential surfaces as in Figure 19. However, in this embodiment, the radially inner end of the tab has a smaller dimension than the radially outer end.

[0105]

[0101] The hydrostatic annular seal 201 comprises at least one material or a combination of materials from the following list: steel, titanium, aluminum alloy, cobalt-based alloy, nickel-based alloy and / or any composite material.

[0106]

[0102] We now refer to figures 21 to 26 which concern the radial sliding of a hydrostatic annular seal 300 on an annular partition 305 of an annular row of stator blades.

[0107]

[0103] With reference to Figure 21, there is shown a sector 310 of an annular row or crown of stator blades which is here a distributor. Such sectors are arranged circumferentially end to end to form the crown of stator blades. This crown carries a hydrostatic annular seal 300 which is shown in Figure 26. It could be of any type as described in the present description, for example those described with reference to Figures 9 or Figures 10 to 20.

[0108]

[0104] All of the distributor crown sectors 310 are identical so that the following description, which relates to one sector of Figure 21, applies to each of the other distributor sectors 310.

[0109]

[0105] Referring to Figure 21, the sector comprises an inner platform 312, an outer platform 314 and blades 316.

[0110]

[0106] The blades 316 are each connected on the one hand to the internal platform 312 and on the other hand to the external platform 314 so as to extend radially through a primary air stream, which is radially delimited by these platforms 312, 314.

[0111]

[0107] The blades of the sector 310 are circumferentially spaced from each other. The external platform 314 is configured to be fixed on a casing of the turbomachine 1.

[0112]

[0108] The sector 310 comprises a radial partition 305 forming the foot of the distributor 310 and which is connected to the internal platform 312 so as to extend radially inwards from the internal platform 312, in the direction of a cylindrical shell 11 of the rotor, the cylindrical shell being shown in FIG. 2 or FIG. 38 or FIG. 41.

[0113] The radial partition 305 is configured to cooperate with a hydrostatic annular seal 300 (Figure 26). The hydrostatic annular seal 300 comprises a sectored radial annular wall 320, formed of a plurality of rapidly inner annular wall sectors arranged circumferentially end to end. The latter are connected by elastically deformable members 322 to a radially outer annular wall 325 fixed to the seal support 324 which comprises a radially outer annular wall 323 and radially outwardly at least one radial annular tab 326, preferably two radial annular tabs as illustrated in Figure 22.

[0114]

[0109] In this regard, Figure 22 shows only a circumferential section of the seal support 324.

[0115]

[0110] With reference to Figure 22, the radial annular legs 326 or flanges are substantially parallel and longitudinally spaced from one another so as to form a U-shaped section defining a space into which the radial partition 305305 of each of the sectors 310310 can be inserted.

[0116]

[0111] The longitudinal distance between the legs 326 is chosen so as to allow adequate longitudinal positioning and maintenance in the longitudinal position of the sectors 310, while allowing its mobility by radial sliding of the partition 305 between the legs 326 (see below). In particular, an axial or longitudinal clearance J1, J2 is left during assembly between the legs 326 and the partition 305 to allow this radial movement. The clearance J1 extends between the upstream leg 326 and the partition 305, and the clearance J2 extends between the partition 305 and the downstream leg 326.

[0117]

[0112] Furthermore, the partition 305 is mounted with a radial clearance J3 relative to the bottom of the space defined by the tabs 326.

[0118]

[0113] In the embodiment shown in Figure 26, the radially external annular wall 324 is formed in a single piece with the elastically deformable members 322, with the radially internal annular wall 320 and with at least one of the annular tabs 326.

[0119]

[0114] Figure 23 shows two orifices 328 made respectively in the upstream tab 326 and the downstream tab 326.

[0120]

[0115] The orifices 328 have a common axis A2 and are designed to receive a pin 330 such as that shown in the figure. The pin 330 is a cylindrical part with axis A2 having two shoulders which define an upstream part 332, an intermediate part 334 and a downstream part 336.

[0116] The intermediate part 334 has a diameter smaller than the diameter of the upstream part 332 and the downstream part 336. The diameter of the upstream part is also smaller than that of the downstream part.

[0121]

[0117] The orifice 328 of the upstream tab 326 of the hydrostatic annular seal 300 is sized to receive the upstream portion 332 of the pin 330 so as to form a tight fit. Similarly, the orifice 328 of the downstream tab 326 of the hydrostatic annular seal 300 is sized to receive the downstream portion 336 of the pin so as to form a tight or sliding fit.

[0122]

[0118] After assembly, the pin 330 is thus carried by the upstream 332 and downstream 436 tabs, forming a complete connection with it.

[0123]

[0119] The pin 330 is configured to cooperate with the distributor, in particular with the radial partition 305 of the sector 310.

[0124]

[0120] With reference to figure 21, the partition 310 of each of the sectors comprises for this purpose an opening 338 which has an oblong shape of the groove type extending radially.

[0125]

[0121] In this example, the opening 338 opens radially towards the inside of the crown sector 310. It could not open radially. This would require different geometric arrangements of the pin and different assembly steps than those presented here.

[0126]

[0122] The opening 338 has a width, or circumferential dimension, allowing it to be crossed by the intermediate part 334 of the pin 330, that is to say a width greater than the diameter of the intermediate part 334 of the pin 330.

[0127]

[0123] The width of the opening 338 is also less than the diameter of the upstream part 332 and the downstream part 336 of the pin 330. Thus, in the event of a break in the connection between the pin 330 and the upstream and downstream tabs 326, the partition 305 of the sector 310 forms an axial stop for retaining the pin 330.

[0128]

[0124] The assembly of this stator element comprises a pre-insertion of the pin 330 into the upstream and downstream tabs 326 by passing the upstream part 332 of the pin 330 through the orifice 328 of the downstream tab 326.

[0129]

[0125] The pin 330 is then fixed to the lugs by forced insertion of its upstream part 332 into the orifice 328 of the upstream lug 326 and, simultaneously, of its downstream part 336 into the orifice 328 of the downstream lug 326.

[0126] The sector 310 is then moved radially inwards so as to introduce the partition 305 axially between the lugs 326 and to insert the intermediate part 334 of the pin 330 into the opening 338 of the partition 305.

[0130]

[0127] These assembly steps make it possible to achieve the configuration illustrated in Figure 25.

[0131]

[0128] In this configuration, the pin 330 forms on the one hand a circumferential stop for the crown sector 310, preventing a displacement of the hydrostatic annular seal 300 and the crown sector 310 relative to each other in rotation around the axis of the sector 310 and making it possible to center the hydrostatic annular seal 300 relative to this axis A1.

[0132]

[0129] On the other hand, taking into account the respective dimensions of the intermediate part 334 of the pin 330 and 330 of the oblong opening 338, the assembly allows radial displacement of the hydrostatic annular seal 300 relative to the sector 310.

[0133]

[0130] The stator assembly may comprise other pins similar to the pin 330, each cooperating with the partition 305 according to the principles described above.

[0134]

[0131] Of course, these principles can be generalized. For example, each of the sectors 310 of the distributor can cooperate with several pawns similar to pawn 330.

[0135]

[0132] Generally speaking, the invention makes it possible to connect the hydrostatic annular seal 300 and the distributor 310 to each other according to a connection defining a radial degree of freedom or radial sliding capable of compensating for differential thermal expansions within the turbine 9.

[0136]

[0133] Finally, the forced mounting of the pins 330 in the orifices 328 of the upstream and downstream legs 326 contributes to the reduction of gas leaks outside the primary vein.

[0137]

[0134] Reference is made to Figures 27 to 33.

[0138]

[0135] The embodiment shown in Figures 27 to 32 of a hydrostatic annular seal 419 is proposed in which a radially outer annular wall 401 is fixed by bolting to a seal support 402.

[0139]

[0136] The hydrostatic annular seal 419 thus comprises a radially internal annular wall 420 sectored and a radially external annular wall also sectored 401.

[0140]

[0137] The seal support 402 is mounted to slide radially on the radial annular partition 403 described previously with reference to FIG. 21. The annular seal support 402 comprises an upstream annular tab 404 and a downstream annular tab 405. The upstream annular tab 404 and the downstream annular tab 405 are connected to each other by a base so as to form a U. The radial annular partition 403 comprises oblong openings 406 opening radially inwards.

[0141]

[0138] In a particular embodiment, illustrated in Figures 27 to 31, the seal support 402 comprises longitudinal and circumferential projections 415 defining between them radial notches in which are engaged radial tabs 416 formed projecting radially outwards from the radially external annular wall sectors 401 of the hydrostatic annular seal. This shape cooperation makes it possible to lock the annular seal in rotation on the seal support 402.

[0142]

[0139] As illustrated in Figure 33, a sheet 414 may be interposed longitudinally between the radial annular partition 403 and the seal support 402. The sheet 414 comprises two radial annular branches connected to each other by a substantially cylindrical base. The branches comprise free end portions which are curved radially inwards so as to form a curved portion which cooperates by form connection with a lateral protrusion of the annular tabs 404, 402 of the annular seal support.

[0143]

[0140] Each elastically deformable member 407 may be elastically connected to at least two circumferentially adjacent radially inner annular wall sectors 408a, 408b. In the embodiment shown in Figures 28, 29 and 32, each elastically deformable member 407 is connected to two circumferentially adjacent radially inner annular wall sectors, one being referred to as a primary sector and the other being referred to as a secondary sector.

[0144]

[0141] It is observed that each elastically deformable member 407 comprises at least one first elastically deformable circumferential blade 408 and at least one second elastically deformable circumferential blade 409 connected at a first common end to the radially external annular wall 401 and of which second ends circumferentially opposite one another with respect to the first common end are each connected to a sector of radially internal annular wall pad 408a, 408b.

[0145]

[0142] In Figures 28, 29 and 32, it is observed that said at least one first blade 408 and said at least one second blade 409 comprise two blades which are radially spaced from each other. The first blades and / or the second blades may be substantially parallel to each other as shown in Figures 28, 29 and 32. The first blades and / or the second blades may also form an angle between them. Among the first blades, a first blade 408 is a first inner blade 408 and the other is a first outer blade 408. Among the second blades, a second blade

[0146] 409 is a second inner blade 409 and the other is a second outer blade 409.

[0147]

[0143] Said first ends of the first and second elastic blades may be connected, as shown in figures 28, 29 and 32, to the same first leg 410 which may extend substantially radially. The first internal blade 408 and / or the second internal blade 409 may be connected to the radially internal end of the first leg 410. The first external blade 408 and / or the second external blade 409 may be connected in the vicinity of the radially external end of the first leg 410, this radially external end of the first leg 410 being connected to the radially external annular wall 401.

[0148]

[0144] The radially inner end of the first leg 410 is devoid of direct connection to one of the two circumferentially adjacent pads, the connection of the first leg

[0149] 410 with the radially inner annular wall being provided indirectly by the first and second blades and the second legs, the latter being described in the following paragraphs.

[0150]

[0145] Said second ends of the first and second elastic blades can be connected, as shown in figures 28, 29 and 32, to a second tab 41 1 which can extend substantially radially. It is observed that there are two second tabs 41 1 which are arranged on either side circumferentially of the first tab 410 and which can be positioned circumferentially in a substantially symmetrical manner with respect to the position of the first tab 410. A second tab 41 1 called second primary tab 411 is connected to the second ends of the first blades and a second tab 41 1 called second secondary tab 411 is connected to the second ends of the second blades.

[0151]

[0146] The term "primary" and the term "secondary" only allow a distinction to be made between the two second legs and their connection to the corresponding primary or secondary pads.

[0152]

[0147] The first outer blade 408 and / or the second outer blade 409 may be connected to the radially outer end of the second primary and secondary legs. The first inner blade 408 and / or the second inner blade 409 may be connected in the vicinity of the radially inner end of a second leg 411, this radially inner end of a second leg 411 being connected to a pad. More precisely, the radially inner end of the second primary leg 411 is connected to the primary pad and for example in the vicinity of a circumferential end thereof. The radially inner end of the second secondary leg 411 is connected to the secondary pad and for example in the vicinity of a circumferential end thereof. Said two ends of the primary and secondary pads are opposite their ends which are circumferentially opposite.

[0153]

[0148] As illustrated in Figure 30, a ring or spacer 413 acts as an axis for the free expansion of the seal support 402.

[0154]

[0149] In a particular embodiment illustrated in figure 32, the radially external annular wall 401 is formed by a radial ring 417.

[0155]

[0150] Reference is made to Figures 34 and 35 illustrating a hydrostatic annular seal 501. This hydrostatic annular seal 501 comprises a sectored radially outer annular wall 502, a sectored radially inner annular wall 503 and an elastically deformable member 504 arranged between said two inner and outer walls.

[0156]

[0151] As illustrated in Figure 34A, the radially outer annular wall 502 is fixed in a seal support 505. Each sector of radially outer annular wall 502 carries a coupling member 506 circumferentially engaged and radially retained in a circumferential groove of the seal support 505. The coupling member 506 has a dovetail shape extending circumferentially. The seal support 505 comprises an upstream wall 507 extending radially inwards and formed opposite the upstream face of the hydrostatic annular seal 501 so as to participate in the sealing of the elastically deformable member 504. The annular part 505 comprises an upstream annular tab 508 and a downstream annular tab 509. The upstream annular tab 508 and the downstream annular tab 509 form a U capable of sliding radially on a radial annular partition of an annular row of stator blades as illustrated in FIG. 21.The radial annular partition may comprise oblong or rectangular openings opening radially inwards and in which are engaged fixing means passing through the upstream and downstream tabs of the seal support 505. The fixing means may comprise pins as described with reference to figures 24 and 25.

[0157]

[0152] Figure 34B illustrates the presence of a member for blocking the radially external annular wall sector on the seal support 505. The blocking is here achieved by a pin 513 engaged and hooped through the support and the coupling member 506 of the seal 501.

[0158]

[0153] As illustrated in Figure 35A, the seal support may be a 360° part which comprises a lateral opening 509 opening inside the circumferential groove of the seal support. Thus, the circumferential groove is made accessible to allow mounting by longitudinal translation of each seal in the lateral opening then by rotation.

[0159]

[0154] The annular seal could be of any type. It may for example be of the type described with reference to Figure 9 and comprise two radially internal annular wall sectors 510a, 510b each formed monolithically with a radial tab 515. Each radial tab 515 is connected to the same tab 514 arranged circumferentially between the two tabs 515. Details of the production of the seal can be read with reference to Figure 9. The coupling of seal support 505 and seal 401 can be produced with other seals of the present document such as the seal described with reference to Figures 10 to 15.

[0160]

[0155] After mounting all the seal sectors, an annular flange 519 is mounted on the downstream face of the seal in order to block the lateral opening. The flange thus comprises protrusions 517 bolted onto the seal support 505.

[0161]

[0156] Figure 36 illustrates a particular embodiment of a hydrostatic sealing annular seal 600.

[0162]

[0157] As described above, a hydrostatic annular seal 600 comprises a radially inner annular wall and a radially outer annular wall between which elastically deformable members are formed. The present description in relation to Figure 36 is applicable to any of the annular seals described with reference to the figures. The elastically deformable seal could be of the type described with reference to Figure 9, or one of Figures 10 to 15. In Figure 36, a radial tab 618 and an elastically deformable blade 620 or strip can be seen.

[0163]

[0158] The radially inner annular wall is sectorized and comprises a plurality of sectors 610 arranged circumferentially end-to-end. Each sector 610 comprises a first circumferential edge 612 and a second circumferential edge (not shown) circumferentially opposite the first edge 612. The first circumferential edge 612 of a sector 610 is placed circumferentially end-to-end with a second circumferential edge of a circumferentially adjacent sector 610.

[0164]

[0159] As illustrated in Figure 36 in relation to a first circumferential edge 612 of a sector 610, a slot 614 is formed in the thickness of the sector 610 and in the first circumferential edge 612 thereof. This slot 614 opens out circumferentially and may have a substantially rectangular shape in section. The same slot 614 is formed in the second circumferential edge of each sector pad.

[0160] According to the present document, a tab 616 is mounted partly in a slot 614 of a first circumferential edge 612 and in a circumferentially facing slot 614 of a second circumferential edge of a circumferentially adjacent pad 610.

[0165]

[0161] As described with reference to Figure 36, each internal sector 610 may comprise a radially internal surface comprising a first portion 610a of substantially cylindrical surface, a second portion 610b of surface formed by a recess, a third portion 610c of substantially cylindrical surface and preferably a fourth portion 610d of frustoconical surface with a section increasing downstream. The recess extends from one circumferential end to the other of the sector 610 and has a concave curved shape which may be formed from a longitudinal succession of flat surfaces. A housing as mentioned in Figure 37 could also be formed in the recess.

[0166]

[0162] It is observed that the slot 614 is formed substantially radially outside the recess such that a plane perpendicular to the longitudinal axis intercepts both the slot 614 and the recess.

[0167]

[0163] In a particular embodiment, the slot extends to the third part 610c. The slot is open circumferentially and axially upstream. The upstream opening is closed by a sealing part (not shown) which prevents air circulation at the upstream outlet. Sealing such as that described with reference to Figures 5 to 7 can be used.

[0168]

[0164] We now refer to Figure 37 showing a hydrostatic annular seal 700 comprising a radially outer annular wall 710 and a radially inner annular wall 712 which is sectorized and formed of a plurality of sectors 714 arranged circumferentially end to end. Elastically deformable members 716 are arranged radially between the inner 712 and outer 710 walls. This seal 700 can be mounted at the radially inner end of an annular row of stator blades of a turbomachine. It could be mounted at any other location where it could perform the same function, for example at a radially outer end of an annular row of stator blades or at the interface between any rotating and fixed part in a turbomachine.

[0169]

[0165] As can be seen, the sector of figure 37 has the same shape as the sector of figure 8. However, what is described below with reference to figure 37 is also applicable to the other joints of the present document, in particular to the joint as shown in figures 9 to 12.

[0166] Each elastically deformable member 716 may comprise two substantially radial tabs 718, 720, a first of which 720 is connected to the sector 714 and a second 718 is connected to the external annular wall 710. The two tabs 718, 720 are connected to each other by elastic blades 722.

[0170]

[0167] It is proposed here to form a housing 724 on the radially internal face of each sector 714, this housing 724 opening radially inwards, this housing 724 having upstream and downstream faces 724a, circumferential faces 724b formed in the thickness of the sector 714. The housing also comprises a bottom wall 724c connecting the radially external ends of the circumferential walls 724b, upstream and downstream 724a. Parts A, B, C and D of figure 37 represent different orientations of the seal and in section for part B, part C and part D.

[0171]

[0168] It is observed that the housing 724 may have a substantially parallelepiped shape, that is to say the lateral or circumferential walls 724b, upstream and downstream 714a and bottom 724c are substantially planar, if the connecting radii of said walls are disregarded. The housing 724 may be substantially centered circumferentially on the circumferential extent of the sector 714.

[0172]

[0169] The housing 724 thus produced does not open circumferentially or longitudinally since the facing circumferential faces 724b and the facing upstream and downstream faces 724a are formed in the thickness of the sector 714.

[0173]

[0170] The housing 724 may extend circumferentially a distance less than 80% of the circumferential extent of the sector. Also, the housing 724 may extend longitudinally a distance less than 50% of the longitudinal extent of the sector 714.

[0174]

[0171] In a particular embodiment of the seal 700, each housing 724 has a depth of at least 50% of the maximum radial dimension of the sector 714.

[0175]

[0172] In Figure 37D, it is observed that the radially internal surface of the sector 714 comprises a first substantially cylindrical surface portion 726a, a second surface portion 716b forming a recess, a third substantially cylindrical surface portion 726c and a fourth frustoconical surface portion 726d with a section increasing downstream.

[0176]

[0173] According to the present document, the housing 724 is formed in the annular recess 726b. The recess 726 may have a concave curved shape. Here, it is composed of a succession of conical surfaces.

[0174] The elastic members 716 could have the shape of those described with reference to figures 9 to 12. In this case, the primary sector and the secondary sector are each provided with a housing 724 formed in the thickness thereof. For the rest of the characteristics relating to the elastic member, reference will be made to the description given with reference to figures 9 to 12.

[0177]

[0175] The integration of a housing 724 as described with reference to Figure 37 could be made on any of the annular seals and assemblies described herein.

[0178]

[0176] The annular seal 700 could further comprise slots formed in the circumferential edges of each sector for receiving a sealing tab as described with reference to FIG. 36.

[0179]

[0177] Reference is now made to Figure 38 schematically representing a partial view of an assembly 800 for a longitudinal axis turbomachine according to the present document. Preferably, such an assembly is implemented in a turbine, in particular a low pressure turbine, of a turbomachine such as previously described with reference to Figure 1. The present document also relates to any type of turbomachine comprising such a turbine, for example a turboprop or a turbojet for an aircraft.

[0180]

[0178] The assembly 800 comprises a cylindrical shell 811 intended to be driven in rotation about the longitudinal axis and an annular row of stator blades 820. The assembly 800 may also comprise two annular rows of moving blades 810 arranged longitudinally on either side of the annular row of stator blades 820 and connected to each other by the cylindrical shell 811. The annular row of stator blades 820 carries a hydrostatic annular seal 822 arranged radially inside the annular row of stator blades 820 and radially outside the cylindrical shell 811, the hydrostatic annular seal 822 cooperating in a contactless sealing manner with the cylindrical shell 811.

[0181]

[0179] In addition, the cylindrical shell 811 comprises an annular layer 812 facing the hydrostatic annular seal 822 which is made of a first material having a hardness greater than a hardness of a material of a radially internal end 823 of the hydrostatic annular seal 822 facing the annular layer 812.

[0182]

[0180] The use of a harder material for the annular layer makes it possible to improve the mechanical resistance of the cylindrical shell compared to the hydrostatic annular seal. Thus, in the event of eccentricity of the rotor following a sudden maneuver or a breakdown, such an assembly makes it possible to mechanically protect the cylindrical shell in the event of prolonged contact between the hydrostatic annular seal and the cylindrical shell. The mechanical integrity of the cylindrical shell can thus be preserved.

[0183]

[0181] The cylindrical ferrule 811 has in particular a circular section of constant radius along the longitudinal axis over at least one longitudinal portion of the cylindrical ferrule. This shape allows for better control of the clearance between the hydrostatic annular seal and the cylindrical ferrule. In particular, the cylindrical ferrule 811 is devoid of wipers.

[0184]

[0182] The hydrostatic annular seal preferably comprises a radially outer annular wall, a radially inner annular wall and a plurality of elastically deformable members, in particular distributed circumferentially around the longitudinal axis. Each of the plurality of elastically deformable members comprises a first substantially radial leg connected to the radially outer annular wall, a second substantially radial leg connected to the radially inner annular wall and at least one elastically deformable blade extending circumferentially. Said at least one blade is connected to the first leg at a circumferential end and to the second leg at an opposite circumferential end.In other words, the first tab provides the connection between one of the circumferential ends of said at least one blade and the radially outer annular wall, and the second tab provides the connection between the other of the circumferential ends of said at least one blade and the radially inner annular wall. The hydrostatic annular seal can thus deform radially thanks to the flexibility offered by said at least one blade connecting together the radially inner annular wall and the radially outer annular wall. The radially inner and outer annular walls, the tabs and the blades are in particular dimensioned to allow the radial deformation of the hydrostatic annular seal to be controlled, and therefore to control a clearance between the hydrostatic annular seal and the cylindrical shell. Such a deformable member is illustrated in Figure 8.

[0185]

[0183] The elastically deformable member could also be of the type described with reference to Figures 9 to 12.

[0186]

[0184] The first material must then have a hardness greater than that of the pad material.

[0187]

[0185] The pad composed of a material having an abradability greater than that of the coating of the ferrule, makes it possible to ensure that the wear during contact between the ferrule and the pad of the hydrostatic seal occurs only on the pad and not on the ferrule.

[0186] The pad may in particular have an aeraulic shape. This allows, by phenomena of depression and overpressure on either side of the pad, the increase of a clearance between the cylindrical ferrule and the hydrostatic annular seal when they approach each other, and conversely, the reduction of the clearance between the cylindrical ferrule and the hydrostatic annular seal when they move away from each other.

[0188]

[0187] The hydrostatic annular seal is preferably made of a metallic material.

[0189]

[0188] The first material may also have an abrasion resistance greater than the abrasion resistance of the material of the radially inner end 823 of the hydrostatic annular seal 822 opposite the annular layer 812.

[0190]

[0189] A portion 814 of the cylindrical ferrule 811 extending longitudinally from one to the other of the two annular rows of moving blades 810 is in particular made of a first material having a hardness greater than the hardness of the second material. In other words, the portion 814 of the cylindrical ferrule 811 made of the second material connects the two annular rows of moving blades. The second material may in particular be adapted to ensure the mechanical transmission of a torque between the two annular rows of moving blades 810.

[0191]

[0190] The second material may have an abrasion resistance lower than the abrasion resistance of the first material.

[0192]

[0191] The second material may in particular be a steel, a nickel-based alloy or a cobalt-based alloy.

[0193]

[0192] The first material and the second material have in particular mechanical resistance and temperature resistance characteristics consistent with the thermomechanical operating conditions of the turbomachine.

[0194]

[0193] The annular layer 812 may have a longitudinal dimension L1 greater than a longitudinal dimension L2 of the hydrostatic annular seal 822 along the longitudinal axis X. Such a characteristic makes it possible to ensure that the hydrostatic annular seal 822 can be radially opposite the annular layer 812 even in the event of relative longitudinal movement between the cylindrical shell 811 and the annular row of stator blades 820. This relative longitudinal movement is commonly referred to as slewing. Slewing may occur in different operating phases of the turbomachine.

[0195]

[0194] With reference to Figure 39, the cylindrical shell 811 may have an annular recess 813 intended to receive the annular layer 812. In particular, the annular recess 813 and the annular layer 812 may be of the same thickness. In other words, the annular layer 812 may not add any excess thickness to the cylindrical shell 811.

[0196]

[0195] With reference to Figure 40, the annular layer 812 may form a projection relative to a first radially external surface 815 of the cylindrical shell 811. The first radially external surface 815 of the cylindrical shell 811 may in particular correspond to a surface that is the most radially inside a radially external periphery of the cylindrical shell 811. For example, the annular layer 812 may form a ring, i.e. extend over 360°. The layer could be partially housed in the shell and partially formed as a projection relative to the external surface of the shell.

[0197]

[0196] The annular layer 812 may have a radial thickness h so as to provide sufficient mechanical resistance to the annular layer in the event of contact between the cylindrical shell and the hydrostatic annular seal.

[0198]

[0197] According to another aspect, a method of manufacturing the assembly 100 as previously described is described. The method comprises the following steps:

[0199] - the installation of the annular layer 812 on the cylindrical shell 81 1,

[0200] - machining a radially external face 816 of the annular layer 812.

[0201]

[0198] The method then makes it possible to ensure that the annular layer 812 complies with the dimensional constraints, geometric tolerances, and surface condition of the cylindrical shell 811.

[0202]

[0199] Reference is now made to Figure 41 schematically representing a partial section of an assembly 900 for a turbomachine with a longitudinal axis according to the present document, and two enlarged views of the assembly. Preferably, such an assembly is implemented in a turbine, in particular a low-pressure turbine, of a turbomachine such as previously described with reference to Figure 1. The present document also relates to any type of turbomachine comprising such a turbine, for example a turboprop or a turbojet for an aircraft.

[0203]

[0200] The assembly 900 comprises a ferrule 931 intended to be driven in rotation around the longitudinal axis X and a stator stage 920 extending around the longitudinal axis X and radially outside the ferrule 931. The ferrule 931 may in particular have a cylindrical shape, at least over a longitudinal portion of the ferrule. The ferrule 931 is in particular devoid of wipers. The assembly 900 may also comprise two annular rows of moving blades 930 intended to be driven in rotation around the longitudinal axis X, the two annular rows of moving blades 930 being arranged longitudinally on either side of the annular row of stator blades 920 and connected to each other by the ferrule 931.

[0204]

[0201] The stator stage 920 comprises an annular row of stator blades 921. More specifically, the annular row of stator blades 921 comprises a radially outer annular platform and a radially inner annular platform 922 between which a plurality of blades extend. The annular row of stator blades 921 comprises a radial partition 923 which extends radially inward from the radially inner annular platform 922.

[0205]

[0202] The stator assembly 920 also comprises a hydrostatic annular seal 950 carried by the annular row of stator blades 921 and radially opposite the shroud 931, the hydrostatic annular seal 950 being configured to cooperate in a contactless seal with the shroud 931.

[0206]

[0203] In addition, the stator stage 920 and more particularly the annular seal comprises a stop system capable of coming into abutment directly or indirectly with the ferrule 931 and making it possible to limit the radial displacement of the seal.

[0207]

[0204] In the context of an overspeed start of a turbine rotor comprising the shroud, the hydrostatic annular seal may come into contact with the shroud, under the effect of a radial expansion of the latter at overspeed. The stop system advantageously makes it possible to reinforce the contact between the stator stage 920 and the shroud 931 to contribute to braking the rotor in the event of overspeed. Such an assembly 910 thus makes it possible to passively brake the rotor. The assembly thus makes it possible to protect the mechanical integrity of the rotor in the event of overspeed.

[0208]

[0205] More specifically, with reference to Figure 42, the hydrostatic annular seal 950 comprises a radially outer annular wall 951, a radially inner annular wall 952 and a plurality of elastically deformable members, in particular distributed circumferentially around the longitudinal axis. The hydrostatic annular seal 950 preferably comprises a ring 959 extending radially outward from the radially outer annular wall 951. For example, the ring may have a U-shaped section, the two branches of the U being arranged on either side of the radial partition. The two branches of the U and the radial partition may be put in position via centering pins.

[0209]

[0206] The radially inner annular wall 952 and the radially outer annular wall 951 may in particular be formed respectively of a plurality of inner wall sectors arranged circumferentially end to end and of a plurality of outer wall sectors arranged circumferentially end to end. Each of the inner wall and outer wall sectors are in particular connected to an elastically deformable member of the plurality of elastically deformable members.

[0210]

[0207] With reference to Figures 43, 44 and 45, each of the plurality of elastically deformable members 953 comprises a first substantially radial leg 955 connected to the radially outer annular wall 951, a second substantially radial leg 956 connected to the radially inner annular wall 952 and at least one elastically deformable blade 954 extending circumferentially. As such, only the blades 954 are capable of deforming, the legs 955, 956 are non-deformable.

[0211]

[0208] Said at least one blade 954 is connected to the first leg 955 at one circumferential end and to the second leg 956 at an opposite circumferential end. In other words, the first leg 955 provides the connection between one of the circumferential ends of said at least one blade 954 and the radially outer annular wall.

[0212] 951, and the second leg 956 provides the connection between the other of the circumferential ends of said at least one blade 954 and the radially internal annular wall

[0213] 952. The hydrostatic annular seal can thus deform radially thanks to the flexibility offered by said at least one blade connecting together the radially internal annular wall and the radially external annular wall.

[0214]

[0209] The radially inner and outer annular walls, the legs and the blades are in particular dimensioned to allow the radial deformation of the hydrostatic annular seal to be controlled, and therefore to control a clearance between the hydrostatic annular seal and the shell. A first clearance J1 (shown in FIG. 41) is defined between the hydrostatic annular seal 950 and the shell 931, corresponding to a nominal clearance in operation between the hydrostatic annular seal and the shell. Alternatively, the first clearance can be defined as a cold clearance of the turbine.

[0215]

[0210] More specifically, the first leg 955 comprises a radially outer end directly connected to a radially inner face of the radially outer annular wall and a radially inner end which is devoid of direct connection to the radially inner annular wall. Similarly, the second leg 956 comprises a radially inner end directly connected to a radially outer face of the radially inner annular wall and a radially outer end which is devoid of direct connection to the radially outer annular wall.

[0216]

[0211] In addition, the first leg 955 and the second leg 956 are in particular adapted not to deform radially. Only the leg 956 is able to move radially with the radially inner annular wall and move closer to (or further away from) the radially outer annular wall.

[0212] Each of the plurality of elastically deformable members 953 may in particular comprise a plurality of radially spaced blades 954, for example two blades. The blades are in particular substantially parallel to each other.

[0217]

[0213] The radially internal annular wall may carry an abradable pad 958 arranged radially opposite the ferrule 931 and capable of wearing in the event of contact with the ferrule 931.

[0218]

[0214] The abradable pad 958 may in particular have an aeraulic shape. This allows, by depression and overpressure phenomena on either side of the pad, the increase of a clearance between the ferrule and the hydrostatic annular seal when they approach each other, and conversely, the reduction of the clearance between the ferrule and the hydrostatic annular seal when they move away from each other.

[0219]

[0215] With reference to Figure 43 schematically representing an exemplary embodiment of the assembly according to the present document, the stop system 940 comprises at least a first radial stop element 941 carried by the radially external annular wall 951 radially opposite the second leg 956 of one of the plurality of elastically deformable members 953. Thus, the first radial stop element can come into abutment against the second leg. The stop elements are here radial protrusions.

[0220]

[0216] Said at least first radial stop element 941 can also be carried by the radially internal annular wall 952 radially opposite the first leg 955 of one of the plurality of elastically deformable members 953. Thus, the first radial stop element can come into abutment against the first leg.

[0221]

[0217] Said at least first radial stop element 941 may also be carried by the second leg 956 of one of the plurality of elastically deformable members 953 radially facing the radially external annular wall 951, or carried by the first leg 955 of one of the plurality of elastically deformable members 953 radially facing the radially internal annular wall 952. Thus, the first radial stop element 941 may come into abutment against the radially internal annular wall when it is carried by the first leg, or against the radially external annular wall when it is carried by the second leg.

[0222]

[0218] The stop system 940 may also comprise at least two first radial stop elements 941, one being carried by the second tab 956 radially opposite the radially external annular wall 951 or vice versa, and the other being carried by the first tab 955 radially opposite the radially internal annular wall 952 or vice versa.

[0223]

[0219] Said at least one first radial stop element 941 makes it possible to reinforce the radial contact between the hydrostatic annular seal and the ferrule, and thus to improve the braking of the ferrule in the event of overspeed. In addition, the first radial stop element is then advantageously directly integrated into the hydrostatic annular seal, making it easier to implement from the point of view of manufacturing the assembly. In particular, the first radial stop element 941 can be formed in the mass of the hydrostatic annular seal.

[0224]

[0220] The first radial stop element 941 may form a radial protrusion.

[0225]

[0221] The first radial stop element 941 may have a first stop surface 945 substantially parallel to a face against which the first stop surface is capable of coming into abutment.

[0226]

[0222] As shown in Figure 43, a second clearance J2 between the first abutment surface 945 and the face against which the first abutment surface is capable of coming into abutment must be less than or equal to the first clearance J1. As shown in Figure 43, a second clearance J2 between the first abutment surface 945 and the face against which the first abutment surface is capable of coming into abutment may be 0.2 mm or more. Thus, when the ferrule deforms radially outward under the effect of an overspeed, the radially outward movement of the radially inner annular wall of the seal is limited, which makes it possible to ensure contact between this wall and the ferrule 931.

[0227]

[0223] The first radial stop element 941 may extend over a portion or all of the longitudinal dimension of the hydrostatic annular seal 950.

[0228]

[0224] In particular, the stop system 940 preferably comprises a plurality of first radial stop elements 941. For example, each of the plurality of elastically deformable members may comprise one of the plurality of first radial stop elements 941.

[0229]

[0225] Figures 44 and 45 show exemplary embodiments of the assembly according to the present document. The assembly may comprise at least one second radial stop element 942, 943 forming a finger extending radially inward from the annular row of stator blades. Said at least one second radial stop element 942, 943 is capable of radially abutting the radially inner annular wall 952 (as shown in Figure 45) and / or the second tab 956 of one of the plurality of elastically deformable members 953 (as shown in Figure 44).

[0230]

[0226] The second radial stop element 942, 943 may be connected to the radial partition 923 at a first end. The second radial stop element 942, 943 may comprise a second end opposite the first end facing the radially outer face of the radially inner annular wall 952 or the radially outer end of the second leg 956 of one of the plurality of elastically deformable members.

[0231]

[0227] The second radial stop element 942, 943 may in particular extend over part or all of the longitudinal dimension of the radial partition 923.

[0232]

[0228] The second radial stop element can radially pass through at least one opening 957a, 957b, 957b' provided in the hydrostatic annular seal.

[0233]

[0229] With reference to figure 44, the second radial stop element 942 is able to come into radial abutment with the second tab 956. A first opening 957a is notably arranged in the radially external annular wall 951, the first opening 957a being opposite the radially external end of the second tab 56. Thus, the second radial stop element 942 passes through the first opening 957a.

[0234]

[0230] With reference to Figure 45, the second radial stop element 943 is capable of entering into radial abutment with the radially inner annular wall 952, in particular with the radially outer face of the radially inner annular wall 952. The second radial stop element 943 passes through a first opening 957a arranged in the radially outer annular wall 951, and a second opening 957b, 957b' arranged in each blade of said at least one blade 954. The second radial stop element 943 may in particular be circumferentially positioned between the first tab 955 and the second tab 956, in particular substantially in the middle of the first tab 955 and the second tab 956.

[0235]

[0231] The second radial stop element 942, 943 may have a second stop surface 946 substantially parallel to a face against which the second stop surface is capable of coming into abutment.

[0236]

[0232] A third clearance between the second abutment surface and the face against which the second abutment surface is capable of coming into abutment may preferably be of the same order of magnitude as the first clearance. This technical characteristic makes it possible to ensure that, when the ferrule extends radially under the effect of an overspeed, then the hydrostatic annular seal and the ferrule come into contact, the hydrostatic annular seal cannot deform radially enough to allow a flow of gas to pass between the hydrostatic annular seal and the ferrule.

[0237]

[0233] The assembly may comprise a plurality of second radial stop elements 942, 943. For example, each of the plurality of elastically deformable members may comprise one of the plurality of second radial stop elements.

[0234] With reference to FIG. 46, at least one third longitudinal stop element 944 of the stop system 940 may advantageously extend longitudinally from the hydrostatic annular seal 950. Said at least third longitudinal stop element 944 is capable of entering into longitudinal abutment with a radial portion 932 of the annular shell 931 facing longitudinally. Such a characteristic makes it possible to ensure contact between the shell and the hydrostatic annular seal in the event of relative longitudinal movement between the shell and the stator stage, and in particular in the event of rupture of the rotor shaft.Thus, said at least one third longitudinal stop element can advantageously contribute to braking the rotor in the event of overspeed.

[0235] Said at least one third longitudinal stop element 944 can preferably have an annular shape.

[0238]

[0236] The stop elements have been presented individually in a non-limiting manner in the preceding description, the assembly being able to comprise a combination of said at least one first radial stop element, said at least one second radial stop element and said at least one third longitudinal stop element.

Claims

Claims

1. A seal (100) for an aircraft turbomachine comprising a plurality of seal sectors distributed circumferentially around a longitudinal axis (X), each seal sector (102a, 102b) comprising a radially outer annular wall sector (106a, 106b) and a radially inner annular wall sector (110a, 110b) connected to each other by an elastically deformable member (105a, 105b), wherein the circumferentially adjacent seal sectors (105a, 105b) in pairs have their respective elastically deformable member monolithically formed from a common deformable elastic member (105), the common deformable elastic member (105) connecting together two annular wall sectors (110a, 110b) radially internal circumferentially adjacent sealing sector and in which the sectors (106a,106b) of radially external annular wall of the seal sectors form a monolithic external shell.,

2. A seal according to claim 1, wherein the common elastically deformable member (105) has a first circumferential end radial leg (120a) connected to a circumferential end of the inner annular wall sector of a first seal sector (110a) and a second circumferential end radial leg (120b) connected to a circumferential end of the inner annular wall sector of a second seal sector, each circumferential end radial leg (120a, 120b) being connected to a common radial leg (118) by a first blade (112a, 112b) and a second blade (114a, 114b) which each extend circumferentially to connect each circumferential end radial leg (120a, 120b) to a common radial leg (118). 18).

3. A seal according to claim 2, wherein said at least one first blade (112a, 112b) and / or said at least one second elastic blade (114a, 114b) comprises at least two blades radially spaced from each other.

4. A seal according to claim 2 or 3, wherein said at least two blades are substantially parallel.

5. A seal according to one of claims 2 to 4, wherein the common radial tab (118) defines a plane of symmetry for the common elastically deformable member (105).

6. A seal according to one of claims 2 to 5, wherein the circumferential end radial tabs (120a, 120b) of the seal sectors are each integral with a circumferential end of a seal sector (110a, 110b).

7. Seal according to one of the preceding claims, in which the common deformable elastic member (105) comprises three radial tabs (120a, 120b, 118), the common deformable elastic member has a common radial tab (118) arranged circumferentially at the junction between the radially external annular wall sectors to achieve the two-by-two junction of the radially internal annular wall sectors of the seal sector.

8. Assembly for an aircraft turbomachine with a longitudinal axis (X) comprising a distributor which has a crown of stator blades comprising a root (403) at the radially internal end of the distributor carrying a seal (501) according to any one of the preceding claims, the seal (100) being intended to cooperate in a contactless seal with a cylindrical shell of a rotor of the turbomachine arranged radially under the distributor.

9. Turbine for an aircraft turbomachine, the turbine comprising a casing, an assembly according to the preceding claim and a rotor which comprises a cylindrical shroud driven in rotation about the longitudinal axis (X) and, the distributor being mounted in the casing and the cylindrical shroud being arranged radially under the distributor.

10. A turbomachine, such as an aircraft turbojet or turboprop, comprising an assembly according to claim 9 or a turbine according to claim 10.

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