Installation of sealing rings on aircraft turbine engines

Abstract

The present invention proposes an aero-turbine engine assembly comprising: an upstream housing (55) to which a guide vane assembly (48a) is fastened; and a downstream housing (58) to which a sealing element (62) of a wear-resistant material for a rotor blade assembly is fastened. The assembly further comprises a shroud ring (66) disposed between the upstream and downstream housings and a fastening member (68) for removably fastening the shroud ring. For fastening to the upstream housing, the guide vane assembly (48a) of the turbine engine is mounted on a downstream hook (480b) of the upstream housing, not on the shroud ring (66), and the downstream housing (58) has an upstream hook to which the sealing element (62) engages for fastening to the downstream housing, or the shroud ring has an upstream hook to which the sealing element (62) is mounted for fastening to the downstream housing.

Description

Technical Field

[0001] In the field of aviation turbine engines, the present invention relates to the design of a sealing and fastening system between a distributor and a sealing element of a movable guide vane arrangement for a turbine engine, and in particular to the ability to provide access to the periphery of a sealing element (in particular what may be commonly referred to as a sealing ring or OSAS) and / or a casing area surrounding the sealing element. Background Art

[0002] From EP2060743, an example of an assembly for an aviation turbine engine is known, which assembly extends around an axis (X) and comprises:

[0003] an upstream casing arranged about the axis X and to which the guide vane means of the distributor are fastened, said upstream casing being axially followed in the downstream direction by the downstream casing,

[0004] a downstream casing arranged about the axis X on which are mounted sealing elements of abradable material intended to face movable guide vane means of the turbine engine arranged to rotate about the axis X;

[0005] A previous proposal was to place a snap-spring type element between the upstream and downstream housings.

[0006] It should be noted that in this application:

[0007] - axially or axially means: along the axis of rotation of the movable guide vane arrangement, or parallel to said axis of rotation, wherein said axis is also the longitudinal axis of the turbine engine about which the (movable) guide vane arrangements of the turbine, the compressor and, if present, the fan, rotate,

[0008] - "radially" means transversely to the axis X, thus along the axis Z; radially, therefore, means that, on the axis X, the outside is further than the inside, and

[0009] - "Upstream" and "downstream" are understood to be axially, relative to the general flow direction of a fluid flowing in upstream and out downstream.

[0010] Another proposal, as in FR 2914350, is to provide a single housing and to fasten the distributor and the movable guide vane arrangement to the housing, one downstream of the other, by coupling them with hooks of the housing.

[0011] One problem is the accessibility to at least one of these hooks and / or to the periphery of the sealing ring at which it is coupled.

[0012] In fact, in the event of a crack in this area of ​​the hook or sealing ring, it may be necessary to completely partially dismantle the relevant area of ​​the turbine engine, which may cause problems in terms of use, time and costs that are difficult to manage.

[0013] The present invention aims to address at least some of the above mentioned disadvantages. Summary of the invention

[0014] In order to improve the situation, the present document proposes that the above-mentioned assembly including the upstream casing and the downstream casing further comprises: a shroud ring:

[0015] - inserted between the upstream casing and the downstream casing about the axis of rotation of the movable guide vane arrangement, and

[0016] - a removable fastening member for removably fastening the shroud, the upstream casing and the downstream casing, said removable fastening member having an additional feature such that

[0017] - for fastening to the first casing, the distributor of the turbine engine is mounted on the downstream hooks of the upstream casing without being coupled to the shroud ring, and:

[0018] - the shroud ring has upstream hooks for coupling a sealing element, said sealing element being mounted on said upstream hooks in order to be fastened to the downstream casing,

[0019] - or the downstream housing has an upstream hook for coupling the sealing element, the sealing element engaging with the upstream hook so as to be fastened to the downstream housing.

[0020] It is proposed that, in the second condition, the shroud ring has no such upstream hook for coupling the sealing element, which facilitates installation in terms of ease, speed, mechanical efficiency - in particular load transfer, balance, etc.

[0021] In other words, it is recommended that:

[0022] if the downstream housing has upstream hooks for coupling the sealing element, the sealing element engages with the upstream hooks in order to be fastened to the downstream housing,

[0023] The shroud ring then does not have any upstream coupling hooks intended for said fastening of the sealing element to the downstream casing.

[0024] The expression "mounted on" includes the possibility that the referenced first part is coupled to the second part.

[0025] In one portion, or preferably in several sectored portions around said axis (X), the sealing element referred to above is annular, the expression "sealing ring" being used hereinafter synonymously with said sealing element or as a possible embodiment of said sealing element, implicitly indicating that said sealing element extends circumferentially around said axis (X).

[0026] In any case, once the shroud ring has been removed, it will in principle be possible to access the periphery of the sealing ring and / or the surrounding housing area via upstream (once the movable guide vane arrangement is positioned immediately downstream of the distributor). Furthermore, access to the distributor and the surrounding housing area will also be possible.

[0027] It will be appreciated that the proposed solution concerns the manner in which the distributor and the sealing ring are fastened to the associated housing. It is therefore also proposed that:

[0028] - for fastening to the upstream casing, the distributor of the turbine engine is furthermore coupled to an upstream hook of the upstream casing, said upstream hook being located further upstream of the upstream casing than a downstream hook of the upstream casing, and / or

[0029] For fastening to the downstream housing, the sealing ring is furthermore coupled to a downstream hook of the downstream housing, said downstream hook being located further downstream of the downstream housing than the upstream hook for coupling the sealing ring.

[0030] Thus, despite the novelty of the above-referenced design of the removable shroud ring and its structural environment, it is possible to manufacture these additional couplings in a fairly conventional manner.

[0031] For fastening to the downstream housing, the sealing ring can in particular be held pressed between a hook of the downstream housing and a distributor part which itself is situated further downstream.

[0032] If the shroud ring has upstream hooks for connecting the sealing ring, it may also be necessary to:

[0033] - the sealing ring comprises an upstream edge defining a ridge protruding in an upstream direction relative to the wear-resistant material, and

[0034] The upstream hook of the shroud ring has a circumferential edge which (will be double, since it) will comprise a radially inner wall and a radially outer wall between which the upstream edge of the sealing ring can engage.

[0035] Thus, on the shroud ring there will be hooks open in the downstream direction, which form a circumferential groove, in which (the structural portion of the sealing ring protruding in the downstream direction) will be mounted.

[0036] This makes it possible not only to avoid providing an upstream hook on the downstream housing for the upstream coupling of the sealing ring, but also to correctly position / center the sealing ring, which, thanks to the resulting circumferential groove, ensures its fastening.

[0037] Likewise, if the shroud ring has upstream hooks for coupling the sealing ring, it may also be necessary that the radially outer wall of the double circumferential edge is axial and that the radially inner edge of the downstream casing abuts against said radially outer wall.

[0038] This will facilitate the relative positioning of the housings and their respective retention, especially with regard to the thermal and mechanical stresses and / or assembly / disassembly constraints encountered.

[0039] In this regard, and for the ultimate purpose of this further enhancement, the upstream casing may have a downstream end edge that is radially outward and has (terminates in) an axial circumferential shoulder that is configured to radially outwardly cover the upstream end of the downstream casing, wherein the upstream casing may have a radially inward upstream end edge.

[0040] In order to further enhance the aspects of positioning / centering the sealing ring and ensuring its tightening, it may also be necessary to form the radially inner wall and the radially outer wall of the circumferential groove axially in the same way as the upstream edge of the sealing ring, thereby ensuring axial relative positioning and engagement / disengagement, facilitating assembly / disassembly.

[0041] Furthermore, with regard to these aspects regarding the relative positioning of the housing, the corresponding retention and the resistance to mechanical stresses, it is also provided that, if the shroud ring has no upstream hook for coupling the sealing element (thus creating a situation in which this upstream hook is on the downstream housing), then the shroud ring can have an axial circumferential edge against which the radially inner edge of the downstream housing will abut.

[0042] Therefore, in this case it will be especially possible to have a solution with good housing load resistance.

[0043] In addition, it is proposed that:

[0044] - an upstream seal and a downstream seal are respectively provided between the shroud ring and the upstream distributor and between the shroud ring and the downstream sealing ring, and

[0045] - radially externally with respect to the seal, the shroud ring has at least one channel or circuit for ventilation, connecting:

[0046] an upstream volume defined between the shroud ring, the upstream casing and the distributor and isolated from the fluid jet by an upstream seal, wherein a portion of the distributor and a portion of the movable guide vane arrangement extend radially inwardly relative to said seal, and

[0047] - a downstream volume defined between the shroud ring, the downstream casing and the movable guide vane arrangement and to be isolated from said fluid jet by a downstream seal.

[0048] It will thus be possible to facilitate the sealing and therefore limit the leakage of the hot fluid from the jet and its flow to the outside and in particular to those areas for the coupling / suspension of the distributor and the sealing ring.

[0049] To also facilitate this sealing, it is further proposed that the shroud ring has a radially inner end on either side of which the following extend (preferably into close proximity):

[0050] - upstream an axial stop of the distributor abutting against the radial surface of the shroud ring,

[0051] - Downstream is a raised portion of the upstream end of the sealing ring, which projects in the upstream direction relative to the wear-resistant material.

[0052] Likewise, in order to facilitate the above-cited sealing and relatively easy access to precise stable positioning of the shroud ring, it is further proposed that:

[0053] - on either side of the shroud ring, the upstream casing and the downstream casing each have a radial edge as a removable fastening member through which bolts for removably fastening the shroud ring pass, and

[0054] The shroud ring is in the form of a radial ring which extends radially inwards beyond the radial edges of the upstream and downstream casings and beyond the circumferential edges to an end which is axially inserted between the distributor and the sealing ring.

[0055] The invention also relates to an aircraft turbine engine comprising the assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] [ Figure 1 ] Figure 1 Schematically represented is a twin-flow aircraft turbine engine according to a side view (symmetrical longitudinal half-section relative to the axis X).

[0057] [ Figure 2 ] Figure 2 Schematically Figure 1 Part of a low-pressure compressor of a turbine engine in FIG. 1 , as a cross section along the axis X, which part is provided with the solution according to the invention according to a first embodiment.

[0058] [ Figure 3 ] Figure 3 Schematic representation of the low pressure compressor and Figure 2 The same part as a cross section along the axis X, but with a second embodiment of the solution according to the invention.

[0059] [ Figure 4 ] Figure 4 express Figure 2 A magnified portion of the view in .

[0060] [ Figure 5 ] Figure 5 express Figure 3 A magnified portion of the view in . DETAILED DESCRIPTION

[0061] The following non-limiting examples of applications and solutions according to the invention relate to the possibility of enabling the repair of the OSAS (or sealing ring) of the first stage of the low-pressure turbine of an aircraft turbine engine and / or enabling easy repair or replacement of the associated hook (if it is on the shroud) (reference 66 hereinafter).

[0062] therefore, Figure 1 A turbine engine 10 is represented which may comprise all or part of the features according to the invention presented above.

[0063] In the following description, the same reference numerals denote parts that are the same or have similar functions.

[0064] The gas turbine engine 10 is here a twin-flow and twin-body turbojet engine.

[0065] Along the flow direction of the airflow F in the turbine engine from upstream (AM) to downstream (AV), the turbine engine 10 includes a fan 12, a low-pressure compressor 14, a high-pressure compressor 72, an annular combustion chamber 43, a high-pressure turbine 40 and a low-pressure turbine 44. The rotor 72R of the high-pressure compressor 72 and the rotor 40R of the high-pressure turbine 40 are connected by a high-pressure (HP) shaft 42 and form a high-pressure body with it. The rotor 14R of the low-pressure compressor 14 and the rotor 44R of the low-pressure turbine 44 are connected by a low-pressure (LP) shaft 16 and form a low-pressure body with it. In the upstream part of the turbine engine 10, the fan 12 includes blades 13 connected to a fan shaft 18, and the fan shaft is rotatably connected to the LP shaft 16 by means of a reduction gear 20 in the example shown. The fan 12 and the low-pressure compressor 14 thus form a low-pressure upstream module of the turbine engine. The HP shaft 42 and the BP shaft 16 extend along the longitudinal axis X of the turbine engine 10. The turbine engine 10 also comprises a fan casing 21 which extends around the blades 13 and defines the air inlet jet of the air flow F.

[0066] A portion F1 of the air F enters the inner annular flow jet 22 of the primary air flow and another portion F2 feeds the outer annular flow jet 23 of the secondary air flow.

[0067] The jet 22 passes through the low-pressure compressor 14 and the high-pressure compressor 72, the combustion chamber 43 and the high-pressure turbine 40 and the low-pressure turbine 44. The outer jet 23 surrounds the casings of the compressors and turbines and merges with the main jet 22 in the nozzle (not shown) of the turbine engine 10. The HP turbine 40 and the BP turbine 44 are each housed in a corresponding HP turbine casing 45 and a corresponding LP turbine casing 58, which carry a fixed series of corresponding distributors such as 46a and 48a, 48b, 48c inserted between a series of movable guide vanes such as 40a, 44a, 44b, 44c. Downstream of the LP turbine casing 58, the exhaust casing 50 is used to discharge the gases circulating in the main jet 22. The inter-turbine casing 55 is arranged between the HP turbine 40 and the LP turbine 44, more specifically, between the HP turbine casing 45 and the LP turbine casing 58.

[0068] Two possible embodiments of the solution according to the invention are described below, which have been designed more specifically and are described in detail in Figure 2 and 3 Schematically represented in .

[0069] First, and if available Figure 2 and 3 As can be seen in detail in FIG. 4 , the solution according to the invention can be applied in particular at the level of the connection zone between the upstream casing and the downstream casing, at the LP turbine 48 .

[0070] This area can therefore correspond to Figure 1 The one marked I in , and therefore corresponding to the area connecting the inter-turbine casing 56 and the LP turbine casing 58 , illustrates an aviation turbine engine assembly 60 extending around the axis X and comprising means facilitating access to the OSAS (hereinafter 62 ).

[0071] Thus, in this assembly (e.g. marked 60), the guide vane arrangement of the distributor, e.g. the first 48a of the LP turbine 48, is peripherally fastened to an upstream casing, e.g. casing 55, which is therefore axially followed in the downstream direction by a downstream casing, e.g. the LP turbine casing 58, which is also arranged around the axis X.

[0072] A sealing element 62 provided with an abradable material 64 , which is intended to face a movable guide vane arrangement, such as the guide vane arrangement 44 a configured to rotate about the axis X, is also fastened to this housing at the periphery.

[0073] As mentioned above, the sealing element 62 will conventionally be referred to as a "sealing ring."

[0074] At the periphery, the sealing ring 62 comprises an annular structure 620 to be fastened to the downstream casing 48 , having upstream and downstream fastening elements at the periphery.

[0075] At the inner periphery, the annular structure 620 comprises a wear resistant material 64 which is radially disposed to the movable guide vane arrangement 44a in alignment therewith.

[0076] The annular structure 620 may generally be in the form of a ring made in one piece or formed by continuous circumferential sectors (generally referred to as ring sectors) around the axis X, in the same way as the wear-resistant material 64 may comprise a circumferentially continuous block.

[0077] As with any movable guide vane device, the guide vane device 44a comprises movable blades continuous around its circumference movable about the axis X, each of which has a series of movable blade platforms, such as 440, at the periphery, each of which is provided with an external seal (or sealing element) 442, which is surrounded on the outside by a wear-resistant material 64 with a small radial gap.

[0078] To facilitate the access cited above, the assembly 60 further comprises a shroud ring 66 inserted between the upstream casing 55 and the downstream casing 58 about the axis X and a removable fastening member 68 for removably fastening the shroud 66 , the upstream casing 55 and the downstream casing 58 together.

[0079] For its fastening 480 b to the upstream casing, the distributor (here 48 a ) is therefore mounted on the downstream hooks 550 b of the upstream casing 55 without being hooked to the shield 66 (ie not being coupled in contact therewith).

[0080] Regarding the fastening to the downstream housing, two solutions are therefore proposed:

[0081] - the shield 66 has an upstream hook 660a, which is used to engage with the sealing ring 62 in order to fasten it to the downstream casing; see Figure 3 ,

[0082] - or the downstream housing 58 has an upstream hook 580a with which the sealing ring 62 engages in order to fasten it to the downstream housing, the shroud ring 66 then being devoid of this upstream hook on which the sealing element is mounted; see Figure 2 .

[0083] In the description, hook and guide are synonymous, and the same applies to hooking and coupling. Therefore, the sealing ring 62 and the distributor 48a are each coupled with a guide formed on the upstream casing, the downstream casing or the shroud ring 66.

[0084] Depending on the situation, the upstream hook 660a or 580a corresponds to the upstream fastening element cited above.

[0085] If the solution of upstream hook (or guide rail) 580a on the downstream housing is selected, such as in Figure 2 In the embodiment of the present invention, this hook is then used for coupling with a cooperating hook 620a1 which is defined for the upstream fastening of the sealing ring 62.

[0086] The upstream hook (or guide rail) 580 a 1 protrudes at the periphery of the annular structure 620 .

[0087] If the solution of upstream hook (or guide rail) 660a on shield 66 is selected, such as in Figure 3 In the embodiment of the present invention, this hook is then used to connect with the cooperating hook 620a2, which is defined for the upstream fastening of the sealing ring 62.

[0088] An upstream hook (or guide rail) 620 a 2 protrudes at the periphery of the annular structure 620 .

[0089] Furthermore, for downstream fastening 582 to the downstream housing (here 58 ), the sealing ring 62 may be further mounted on a downstream hook 582 b of the downstream housing 58 , which is located further downstream of this downstream housing than the upstream coupling hook 660 a or 580 a .

[0090] Specifically, the downstream fastening element 582 can be defined on the annular structure 620 by an annular groove 70 which opens radially outwards and in which the downstream guide or hook 582b is mounted.

[0091] The additional circumferential hooks 74 may ensure fastening by radially clamping the downstream rail or hook 482 b and the downstream portion of the annular structure 620 .

[0092] The guide rails or hooks 580a, 582b, 550b, 660a extend in the downstream direction.

[0093] The respective associated guide rails or hooks 620a1, 74, 480b, 620a2 extend in the upstream direction.

[0094] The additional circumferential hook 74 , which engages via the downstream, may open in the upstream direction.

[0095] However, it may be preferred that, for its downstream fastening 582, the sealing ring 62 is retained on the downstream hook 582b by being squeezed by means of a distributor portion (not shown) positioned immediately downstream, and the downstream hook 582b is pressed against at the periphery of this distributor portion by a strip along the inner surface of the downstream shell.

[0096] Furthermore, the distributor (here 48a) is further mounted on (coupled to) an upstream hook 550a of the upstream housing for upstream fastening 480a to the upstream housing 55. This upstream hook 550a is located further upstream of the upstream housing 55 than the downstream hook 550b.

[0097] Like any distributor, the distributor 48a comprises stationary blades circumferentially continuous around the axis X. Each stationary vane has a platform 485 at the periphery. The upstream coupling hooks or guides 480a and downstream coupling hooks or guides 480b cited above are formed at the free ends of the spoiler mounted on corresponding hooks of the casing, respectively upstream 483a and downstream 483b.

[0098] The respective associated guide rails or hooks 620a1, 74, 480b, 620a2 extend in the upstream direction.

[0099] While the hooks or rails 580a, 582b, 550b, 620a1, 620a2 may be formed from a single protrusion, the hooks or rails 480b, 660a, 74 may be formed from dual protrusions.

[0100] Therefore, in the possible Figure 3 In this case, the requirement is to prioritize:

[0101] the sealing ring 62 comprises an upstream edge as an upstream hook 620a2 defining a ridge protruding in the upstream direction relative to the wear-resistant material 64, and

[0102] The upstream hook 660a of the shroud ring 66 has a circumferential edge or a double circumferential rail with a radially outer wall 660a1 and a radially inner wall 660a2 between which the upstream edge of the sealing element forming the hook 620a2 engages.

[0103] For favorable load orientation, the upstream hooks 620a2 and 660a (and therefore the walls 660a1 , 660a2 if they are present) will be axial, as will the free ends of the other hooks or rails.

[0104] For the setting of the relevant parts and for an advantageous load transmission, it can furthermore be provided that the radial stop is implemented by means of the guard ring 66 .

[0105] Consider two possibilities:

[0106] -like Figure 2 As described in the embodiment of the present invention, the shroud ring 66 has no upstream hook on which the sealing ring 62 is mounted, the shroud ring having an axial circumferential edge 660 abutting against (the free end of) the radial inner edge 583 of the downstream casing 58, or

[0107] -like Figure 3 As illustrated in FIG. 6 , the radially outer circumferential edge 660a1 is axial and the radially inner edge 583 of the downstream casing 58 abuts against the radially outer circumferential edge.

[0108] For a durable, easily implemented and removable fastening, the fastening member 68 will preferably extend axially continuously through the upstream casing 55 , the shroud 66 and the downstream casing 58 .

[0109] Axially, on either side of the shroud ring 66, the upstream casing 55 and the downstream casing 58 will effectively each have a radial edge 555 or 585, respectively (see Figure 2 , 3 ), as the removable fastening member, the bolts 681 providing the removable fastening of the shroud ring 66 will pass through the radial edge.

[0110] The radial edge 555 extends outwardly. The radial edge 585 extends inwardly.

[0111] The bolts 681 will be regularly distributed circumferentially around the axis X.

[0112] Furthermore, the shroud ring 66 will then effectively be in the form of a radial ring extending radially inwardly:

[0113] - beyond said radial edges 555 or 585 of the upstream and downstream casings,

[0114] - and exceeds the circumferential edge 660 or 660a1,

[0115] - to the end 661 inserted axially between the distributor 48a and the sealing ring 62. Thus, a dual mechanical and sealing effect is favored.

[0116] In particular in this case, it can also be provided that, for the same purpose, the shroud ring 66 has a radially inner end (at Figure 2 , 3 660), the following will extend axially on either side thereof:

[0117] - upstream is the axial stop 481 of the distributor 48a, which abuts against the radial surface 663 of the shroud ring 66, and

[0118] Downstream is the upstream end bulge 623 of the sealing ring 62 , which protrudes in the upstream direction relative to the wear-resistant material 64 .

[0119] The axial stop 481 can effectively be formed at the periphery of each of the stationary vanes of the distributor 48a by a radial edge at the downstream face of a downstream rib 483b incorporating a downstream hook 480b at its end.

[0120] For load control purposes, the axial stop 481 will be effectively formed substantially coaxially with the coupling between the hooks 480b and 550b.

[0121] The seal around the shroud ring 66 in this area is moreover shaped so as to limit leakage of the (hot) fluid F1 from the jet 22 to the periphery, over the platforms 485 , 440 or to the upstream casing 55 and / or the downstream casing 58 .

[0122] In order to protect the above-cited connections of the housing and the distributor 48 a and the sealing element 62 , it is further proposed that seals 76 are provided respectively between the shroud ring 66 and the distributor 48 a upstream and between said shroud ring and the sealing ring 62 downstream.

[0123] Two solutions are proposed for these seals 76:

[0124] - the seal 76 comprises an upstream seal 76a and a downstream seal 76b, for example an omega seal, which is respectively set between the shroud ring 66 and the radial face of the distributor 48a upstream and between the shroud ring and the radial face of the sealing ring 62 downstream, as in Figure 2 middle,

[0125] - or the seal 76 comprises a sectorized upstream seal 76a and a hook or guide 620a2 as a downstream seal (on its unengaged portion in the upstream direction in the guide 660a), which are respectively set between the shroud ring 66 and the radial surface of the upstream distributor 48a and between the shroud ring and the radial portion 621 of the downstream annular structure 620, which is located upstream of the wear-resistant material 64, such as in Figure 3 middle.

[0126] The raised portion 623 extends beyond the radial portion 621 radially inwardly and in the upstream direction, thereby defining an upstream end of the annular structure 620 of the sealing ring 62 .

[0127] It would therefore be possible to produce radially externally with respect to these seals 76:

[0128] an upstream volume 78a defined between the shroud ring 66, the upstream casing 55 and the distributor 48a (the end of its rib 483b), this upstream volume 78a being isolated from the jet 22 by the upstream seal 76a or also by the downstream support 481 resting against the shroud ring 66 and the coupling 480b, and

[0129] a downstream volume 78b defined between the shroud ring 66, the downstream casing 58 and the sealing ring 62 (its annular structure 620), this downstream volume 78b being isolated from the jet 22 by the following downstream seal 76b: a coupling support between the guide rail 660a and the hook 620a engaged therein particularly for this purpose, as in Figure 4 solutions in, or structural seals, such as Omega seals, as in Figure 5 in the solution.

[0130] Once these upstream volumes 78a and downstream volumes 78b have been created, it will furthermore be possible to enhance the control of the temperature rise around the jet 22 .

[0131] It is therefore then proposed that, radially externally with respect to the seal 76 a , the shroud ring 66 has at least one ventilation channel or circuit 80 which connects the upstream volume 78 a with the downstream volume 78 b .

[0132] For this connection, the ventilation circuit 80 has at least one upstream opening 80a leading to the upstream volume 78a and at least one downstream opening 80a leading to one of the passages 82 and one of the fastening members 68, one of which passes through the edge 585 to allow passage. In this way, the ventilation return 80 is connected to the downstream volume 78a.

[0133] Furthermore, it should be noted that in the portion forming the guide rail portion 621, 623, see also 620a2, when such a portion exists, the sealing pieces 624, 626 that ensure the sealing between the sectors of the sealing ring 62 will preferably exist.

[0134] It would therefore be possible to choose that the sealing element 62 , and in particular its annular structure 620 , is formed circumferentially from several sectorized portions around the axis X.

[0135] In this case, it would also be effective to provide that:

[0136] - the upstream end ridges 623 of two circumferentially continuous sectorized parts of the sealing element 62, or the radial parts 621, in particular the annular structures 620 thereof, are circumferentially connected to each other by sealing strips 624, 625, and / or

[0137] The upstream edges 620 a 2 of such circumferentially continuous sectorized portions of the sealing element 62 , in particular the annular structure 620 thereof, are circumferentially connected to one another by a sealing web 626 .

Claims

1. An aircraft turbine engine assembly extending about an axis (X) and comprising: an upstream casing (55) arranged about said axis (X) and to which the guide vane means of the distributor (48a) are fastened, said upstream casing (55) being axially followed in the downstream direction by a downstream casing, a downstream casing (58) arranged about said axis (X) on which is mounted a sealing element (62) of abradable material (64) intended to face a movable guide vane device (44a) of said turbine engine arranged to rotate about said axis (X), Features: - it further comprises: a shroud ring (66) inserted between the upstream casing (55) and the downstream casing (58) around the axis (X); and a removable fastening member (68) for removably fastening the shroud ring (66), the upstream casing (55) and the downstream casing (58) together, - for said fastening thereof to said upstream casing (55), said distributor (48a) is mounted on the upstream casing downstream hook (550b) of said upstream casing (55) without being hooked to said shroud ring (66), and: the shroud ring (66) has a shroud ring upstream hook (660a) for coupling the sealing element (62) for the fastening thereof to the downstream housing (58), - or the downstream housing (58) has a downstream housing upstream hook (580a), and the sealing element (62) is mounted on the downstream housing upstream hook for the fastening thereof to the downstream housing (58).

2. The assembly according to claim 1, characterized in that: if the downstream housing (58) has the downstream housing upstream hook (580a), the sealing element (62) is mounted on the downstream housing upstream hook for its fastening to the downstream housing, The shroud ring then has no shroud ring upstream hook.

3. The assembly according to claim 1, characterized in that For its fastening to the upstream housing (55), the distributor (48a) is further mounted on a distributor upstream hook (550a) of the upstream housing (55), which is located further upstream of the upstream housing (55) than the upstream housing downstream hook (550b).

4. The assembly according to claim 1, characterized in that For the fastening thereof to the downstream casing (58), the sealing element (62) is further mounted on a downstream casing downstream hook (582b) of the downstream casing (58), which is located further downstream of the downstream casing (58) than the downstream casing upstream hook (580a) or the shroud ring upstream hook (660a) on which the sealing element (62) is mounted.

5. The assembly according to claim 1, characterized in that: - the sealing element (62) comprises an upstream edge (620a2) defining a ridge protruding in an upstream direction relative to the wear-resistant material (64), and The shroud ring upstream hook (660a) has a circumferential edge with a radially outer wall (660a1) and a radially inner wall (660a2), and the upstream edge (620a2) of the sealing element (62) engages between the radially outer wall and the radially inner wall.

6. The assembly according to claim 5, characterized in that The radially outer wall (660a1) is axial, and the radially inner edge (583) of the downstream housing (58) abuts against the radially outer wall.

7. The assembly according to claim 1, characterized in that Without the shroud ring upstream hook, the shroud ring (66) has a circumferential edge (660) which is axial and against which the radially inner edge (583) of the downstream casing (58) abuts.

8. The assembly according to claim 1, characterized in that The shroud ring (66) has a radially inner end with extending on either side: - upstream is an axial stop (481) of the distributor, which abuts against the radial surface of the shroud ring (66), - downstream is a raised portion (623) of the upstream end of the sealing element (62), which projects in the upstream direction relative to the wear-resistant material (64).

9. The assembly according to claim 1, characterized in that: an upstream seal (76a) and a downstream seal (76b) are respectively arranged between the shroud ring (66) and the distributor (48a) upstream and between the shroud ring and the sealing element (62) downstream, and Radially externally relative to the upstream seal (76a) and the downstream seal (76b), the shroud ring (66) has at least one ventilation circuit (80) connecting an upstream volume (78a) defined between the shroud ring (66), the upstream casing (55) and the distributor (48a) and isolated from the fluid jet (22) by the upstream seal (76a), wherein a portion of the distributor (48a) and a portion of the movable guide vane arrangement (44a) extend radially inwardly relative to the upstream seal (76a) and the downstream seal (76b), and a downstream volume (78b) defined between the shroud ring (66), the downstream casing and the movable guide vane arrangement (44a) and isolated from the fluid jet (22) by the downstream seal (76b).

10. The assembly according to claim 5, characterized in that: - on either side of the shroud ring (66), the upstream casing (55) and the downstream casing (58) each have a radial edge (555, 585) as the removable fastening means through which bolts (681) for removably fastening the shroud ring (66) pass, and The shroud ring (66) is in the form of a radial ring which extends radially inwards beyond the radial edges of the upstream casing (55) and the downstream casing (58) and beyond the circumferential edge (660) to an end which is axially inserted between the distributor and the sealing element (62).

11. The assembly according to claim 8, characterized in that: - said sealing element (62) is formed circumferentially by several sectorized portions around said axis (X), The upstream end ridges (623) of two circumferentially continuous sectorized portions of the sealing element (62) are circumferentially connected to each other by a first sealing sheet (624).

12. The assembly according to claim 5, characterized in that: - said sealing element (62) is formed circumferentially by several sectorized portions around said axis (X), The upstream edges (620a2) of two circumferentially continuous sectorized portions of the sealing element (62) are circumferentially connected to each other by a second sealing sheet (626).

13. An aircraft turbine engine comprising an assembly (60) according to any one of claims 1 to 12.

Images