Turbine for turbine engine

Abstract

The invention relates to a turbine (1) for a turbine engine, extending along an axis, comprising an annular casing (4) and at least one turbine stage (1), said at least one turbine stage comprising a nozzle (2) and a rotor wheel (5) surrounded by a sealing ring (10), said sealing ring comprising an abradable element, said wheel (5) and said sealing ring (10) being located downstream of said nozzle (2), said sealing ring (10) having an upstream end retained on said casing (4) by means of a locking member (12, 12a), said turbine having a locking member (12, 12a) which is secured to said locking member (12, 12a). (12, 12a) and an elastic sealing member (48) in contact with the nozzle or the housing (4) to press the locking member (12, 12a) against the sealing ring (10), the locking member comprising a radial outer portion (12a) having a generally C-shaped cross-section and a radial portion (12b) extending radially inwardly from the outer portion (12a), wherein the sealing member comprises two elastic seals (48, 49) supported on the radial portion (12b) on either side of the radial portion (12b).

Description

Technical Field

[0001] The present invention relates to a turbine for a turbine engine, such as an aircraft turbojet or turboprop. Background Art

[0002] A turbine engine conventionally comprises, from upstream to downstream in the direction of air flow in the turbine engine, a fan, a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine, a low-pressure turbine and an exhaust jet nozzle.

[0003] Figure 1 and 2 1 shows a low-pressure turbine 1 of a turbine engine according to the prior art. The turbine engine comprises four stages, each comprising a nozzle 2 formed by an annular row of stationary blades 3 carried by an outer casing 4 of the turbine 1 , and an impeller 5 located downstream of the nozzle 2 .

[0004] The wheels 5 comprise disks 6 assembled axially relative to one another, as well as an annular clamp 7 and supporting radial vanes 8. These wheels 5 are connected to a turbine shaft (not shown) by means of a drive cone 9 fastened to the annular clamp 7 of the disks 6.

[0005] The terms axial, radial and circumferential are defined relative to the turbine engine axis, which merges with the axis of the low-pressure turbine 1 .

[0006] The outside of each wheel 5 is surrounded by a sealing ring 10 made of abradable material, with a small gap. The ring 10 is formed by sectors circumferentially fastened to the casing 4 of the turbine 1 by means of locking means 12. Each sector comprises a radially outer support 13 and a radially inner block 14 of abradable material fastened to the support 13.

[0007] The nozzle 2 comprises a radially inner shell 15 and an outer shell 16 which delimit therebetween an annular air flow jet 17 in the turbine 1 and between which the blades 3 extend.

[0008] The support 13 comprises an upstream tab 18 which engages in a groove 19 of an upstream track 20 of the housing 4. The tab 18 is held in place in the groove 19 using a generally C-shaped locking member 12. The locking member 12 is axially retained by the downstream edge 21 of the outer shell 16 of the nozzle 2 located completely upstream.

[0009] This downstream edge 21 comprises an axial portion 22 that engages in a groove 23 formed by a track 24 of the housing 11. Furthermore, an elastic sealing member 25 is mounted between the housing 4 and said downstream edge 21, said member tending to push said edge 21 back downstream while bearing on the locking member 12.

[0010] The downstream end of the support 13 is held supported on a downstream rail 26 of the housing 4 by means of the nozzle 2 situated downstream.

[0011] The rotor bucket 8 comprises a radially outer platform 27 from which extends a strip 28 cooperating with the block of abradable material 14 to form a dynamic seal.

[0012] In order to improve the performance of the turbine engine, it is necessary to limit the leakage flow in the zone located between the sealing ring 10, the casing 4 and the nozzle 2 (upstream and downstream). In this regard, an upstream annular sealing plate 29 is mounted on the support 13 of the sealing ring 10 and extends in the upstream direction in the gap formed between the upstream end and the downstream edge 21 of the sealing ring 10.

[0013] Furthermore, a downstream annular sealing plate 30 is mounted between the downstream end of the support 13 and the downstream rail 26 of the casing 4 , said downstream plate 30 extending in the upstream direction between the support 13 and the casing 4 to extend in the annular space formed between these elements.

[0014] The plates 29, 30 are formed by angular partitions placed circumferentially end to end to form a seal over the entire circumference. However, there is no overlap between the circumferential ends of the plates 29, 30 so that leakage flows occur between the different partitions of the plates 29, 30 during operation.

[0015] It is necessary to ensure a good seal at these plates 29 , 30 .

[0016] Furthermore, it has been observed that the nozzle 2 located downstream is subject to higher thermomechanical stresses. This stress is due, in particular, to the temperature difference between the radially inner region of the outer shell 16 of the nozzle 2 and the radially outer end of the downstream edge 21. This stress affects not only the outer shell 16 but also the blades 3. It is also desirable to reliably retain the locking member 12 in place to improve the seal at the interface between the nozzle 2, the housing 4, and the sealing ring 10. Summary of the Invention

[0017] The object of the present invention is to remedy the disadvantages listed above simply, reliably and at low cost.

[0018] To this end, the present invention relates to a turbine for a turbine engine, which extends along an axis, the turbine comprising an annular casing and at least one turbine stage, the at least one turbine stage including a nozzle and a rotor wheel surrounded by a sealing ring comprising an abradable element, the wheel and the sealing ring being located downstream of the nozzle, the sealing ring comprising an upstream end retained on the casing by a locking member, the turbine being characterized in that it comprises an elastic sealing member in contact with the locking member and with the nozzle or the casing in order to press the locking member against the sealing ring.

[0019] The terms axial, radial and circumferential are defined relative to the turbine engine axis, which merges with the axis of the low-pressure turbine.

[0020] The sealing member also performs the function of retaining the locking member.

[0021] By means of the elastic sealing member the locking member is held in position, which ensures an improved seal.

[0022] The sealing member may comprise at least one axially deformable annular seal.

[0023] The use of a deformable (especially elastically deformable) seal makes it possible to allow a slight axial movement of the elements relative to each other. This deformable seal can also perform an axial return function and can exert an axial force.

[0024] The locking member may include a portion having a generally C-shaped cross-section.

[0025] The sealing member may comprise at least one annular seal located radially inwardly of the portion having a generally C-shaped cross-section.

[0026] The locking member may include a radially outer portion having a generally C-shaped cross section and a radial portion extending radially inwardly from the outer portion, the sealing member including two elastic seals supported on the radial portion on either side thereof.

[0027] The sealing ring may comprise a portion extending axially upstream and positioned at least partially axially facing towards the locking member and / or the sealing member.

[0028] The axially extending portion may extend axially upstream from the locking member and / or the sealing member.

[0029] The sealing ring may be zoned and may comprise a plurality of zones arranged end to end on the circumference, the sealing element extending between ends of circumferentially adjacent ring zones.

[0030] The sealing element may be formed by a strip or a foil.

[0031] The sealing element may be located at least in the portion of the sealing ring extending axially upstream.

[0032] The sealing element thus makes it possible to improve the heat protection of the sealing member and the locking member, thereby protecting them from being subjected to hot gases from the air flow jet.

[0033] The nozzle may comprise a radial outer shell and a radial inner shell connected by radial vanes, the outer shell comprising at least one downstream edge extending radially outwardly from the outer shell and mounted on the housing, the edge extending at least partially axially towards the locking member.

[0034] The nozzle may comprise a radial outer shell and a radial inner shell connected by radial vanes, the outer shell comprising at least one downstream edge extending radially outwardly from the outer shell and mounted on the housing, the radial outer end of the downstream edge being located radially inside the locking member.

[0035] In this way it is possible to reduce the radial dimensions of the rim, which limits the thermomechanical stresses applied to the nozzle in operation due in particular to temperature gradients or temperature differential effects.The sealing ring may comprise a tab held in radial and axial support on a portion of the housing by locking means.

[0036] The tab thus serves to form a radial stop and an axial stop, the positioning of the tab relative to the housing being achieved by the locking member.

[0037] The turbine according to the invention may comprise one or more of the following features, individually or in combination, provided that the combination of features is technically compatible:

[0038] - the sealing member is annular and continuous, ensuring sealing over the entire circumference, unlike the discontinuous sealing members of the prior art, which are compartmentalized and have no circumferential overlap,

[0039] The sealing member is at least partially radially inside the locking member to protect it due to its radially inner position relative to said locking member. Specifically, the sealing member makes it possible to limit heating of the locking member by leaking flows of hot gases from the air flow jet originating from the combustion chamber and passing through the turbine.

[0040] -The nozzles are zoned,

[0041] - the outer shell of the nozzle comprises an upstream edge and a downstream edge each extending radially outwardly from the outer shell,

[0042] The radially inner surface of the outer shell is frustoconical and flares outwards in the downstream direction. This surface is intended to define the air flow jet in the turbine.

[0043] - the upstream edge is mounted on the rails of the housing,

[0044] - Downstream edge mounted on rails of the housing

[0045] - the housing comprises a frustoconical portion, each track extending radially inside said frustoconical portion,

[0046] - each track extends from said frustoconical portion in a downstream direction,

[0047] - the radially outer end of the upstream edge bears radially on the upstream track of the casing,

[0048] a portion of the downstream edge (for example the radially outer end) bears radially on the downstream track of the casing,

[0049] - the downstream edge comprises an axial portion extending in upstream direction from a radial portion of said downstream edge, said axial portion being complementarily engaged in shape in a groove provided in the housing,

[0050] - the radial supports of the wheel rim and the rail are formed by cylindrical surfaces,

[0051] - the housing comprises an upstream part and a downstream part fastened to each other,

[0052] - the upstream part of the housing surrounds the nozzle,

[0053] - the downstream part of the casing surrounds the sealing ring and the impeller,

[0054] - the upstream and downstream parts are fastened to each other at radial clamps of said parts,

[0055] - the housing comprises an upstream track for mounting the upstream tab of the sealing ring,

[0056] - the housing comprises a downstream track for mounting a downstream zone of a sealing ring,

[0057] - an upstream track for mounting the sealing ring extends axially in the upstream direction,

[0058] - the sealing ring comprises an upstream tab comprising a cylindrical surface bearing on a radially inner cylindrical surface of the corresponding upstream track, and a radial surface bearing on an upstream radial surface of the corresponding upstream track,

[0059] - the downstream zone of the sealing ring comprises a cylindrical surface bearing on a complementary cylindrical surface of the corresponding downstream track,

[0060] - the sealing ring comprises a radially outer support and a radially inner block of abradable material fastened to the support,

[0061] The sealing element engages in a groove provided at a circumferential end of the sealing ring subarea.

[0062] - the sealing element extends along a majority of the axial dimension of the partition, for example along at least 50%, preferably at least 80% of said axial dimension,

[0063] - the sealing ring comprises a radially inner surface comprising at least an upstream cylindrical zone and a downstream cylindrical zone, the diameter of the upstream zone being smaller than the diameter of the downstream zone,

[0064] each blade of the impeller comprises an outer platform from which at least an upstream strip and a downstream strip extend radially outwards,

[0065] - the outer platform is frustoconical and flares outwards in the downstream direction,

[0066] - the upstream strip cooperates with the upstream cylindrical zone of the sealing ring, and the downstream strip cooperates with the downstream cylindrical zone,

[0067] the turbine comprises at least one locking member, for example several locking members regularly distributed along the circumference, each locking member comprising a substantially C-shaped locking area,

[0068] - the locking zone comprises a radially outer axial branch and a radially inner axial branch connected by a radial base,

[0069] - the radially outer branches bear radially on the radially outer surface of the corresponding upstream track of the casing,

[0070] - the radially inner branch bears on the upstream tab of the sealing ring,

[0071] - the internal and external branches make it possible to keep the tabs radially supported on the respective upstream rails,

[0072] - the base bears on the upstream end of the tab so as to press the upstream end of the tab on the upstream end of the corresponding upstream track of the housing,

[0073] - the tab comprises an axially extending portion extending in upstream direction from the main zone of the sealing ring, said axial portion bearing radially on a corresponding upstream track of the housing,

[0074] - the tab comprises a portion extending radially outwards from an upstream end of the radial portion of the tab,

[0075] - said radial portion is capable of bearing on the upstream end of the upstream rail of the casing,

[0076] The locking member comprises a positioning or centering zone extending radially inwards from the locking zone. The locking member refers only to the locking zone and not to the positioning and centering zone.

[0077] the locking region and the positioning region are formed from one single piece or, on the other hand, from at least two single pieces fastened to one another,

[0078] - the positioning zone may comprise a portion extending radially inwardly from the locking zone, and cylindrical portions extending axially on either side of the radially inner end of said radial portion,

[0079] - a first annular sealing member extending axially between a radial face of the downstream edge of the nozzle and the positioning zone,

[0080] - a second annular sealing member extending axially between the positioning zone and the radial face of the sealing ring,

[0081] - the first annular part and / or the second annular part are elastically deformable in the axial direction,

[0082] The first annular component and / or the second annular component have a generally ω- or W-shaped cross section.

[0083] - the first and second sealing parts belong to the sealing member,

[0084] - the annular edge extends axially in the downstream direction from a radial face of the downstream edge of the nozzle,

[0085] - the annular edge extends axially in upstream direction from the radial face of the sealing ring,

[0086] - alternatively, the first annular sealing member extends axially between the locking member (for example the base of the locking zone and a radial face of the housing),

[0087] - the second sealing member extends axially between the radial face of the sealing ring and the radial face of the housing,

[0088] - the first sealing member and / or the second sealing member are accommodated in a groove of the housing,

[0089] - the first sealing member and the second sealing member are axially offset relative to each other,

[0090] - the radially outer end of the downstream edge of the nozzle is located radially inside the first sealing part, the second sealing part and / or the locking member,

[0091] - the intermediate element is mounted on the casing from the downstream edge towards the downstream,

[0092] - the internal element is positioned relative to the downstream edge by means of at least one positioning or centering block,

[0093] - said intermediate element extends radially. The use of an intermediate element instead of a downstream edge of large radial dimensions makes it possible to limit the effects of thermal differences between the different zones of the turbine,

[0094] - the radially outer periphery of the intermediate element is fastened between a radial fixture of the first part of the housing and a radial fixture of the second part of the housing,

[0095] - the intermediate element comprises an axial edge extending in the upstream direction bearing radially on the cylindrical surface of the housing,

[0096] an annular sealing member, for example with a W- or ω-shaped cross section, which is elastically deformable in the radial direction, is mounted between the downstream edge and the intermediate element,

[0097] - the sealing member is mounted in a groove of the intermediate element,

[0098] - the first sealing member and the second sealing member are located in the same radial plane,

[0099] -The sealing plate is installed between the outer periphery of the sealing ring and the housing,

[0100] The sealing plate comprises an upstream end fastened at the outer periphery of the sealing ring, and a downstream end mounted radially between the sealing ring and a corresponding downstream track of the casing.

[0101] The invention also relates to a turbine engine comprising a turbine as recited above.

[0102] The invention also relates to an aircraft comprising a turbine or a turbine engine of the type listed above. The aircraft is, for example, an airplane. BRIEF DESCRIPTION OF THE DRAWINGS

[0103] [ Figure 1 ] is an axial cross-sectional half view of a turbine of a turbine engine,

[0104] [ Figure 2 ] is a cross-sectional view of a portion of a turbine according to the prior art,

[0105] [ Figure 3 ] is a sectional view of a portion of a turbine according to a first embodiment of the present invention,

[0106] [ Figure 4 ] is a sectional view of a portion of a turbine according to a second embodiment of the present invention,

[0107] [ Figure 5 ] is a sectional view of a portion of a turbine according to a third embodiment of the present invention. DETAILED DESCRIPTION

[0108] Figure 3 A portion of a turbine 1 according to a first embodiment of the invention is shown. The turbine comprises an annular casing 4 and at least one turbine stage comprising a nozzle 2 and an impeller 5 surrounded by a sealing ring 10 located downstream of the nozzle 2.

[0109] The nozzle 2 is partitioned. The outer shell 16 of the nozzle 2 includes upstream edges 31 ( Figure 4 ) and downstream edge 21.

[0110] The radially inner surface 32 of the outer shell 16 is frustoconical and flares outwards in the downstream direction. This surface 32 is intended to define the air flow jet 17 in the turbine 1 .

[0111] The upstream edge 31 is mounted on an upstream rail 32 of the casing 4. Similarly, the downstream edge 21 is mounted on a downstream rail 24 of the casing 4.

[0112] The casing 4 comprises two parts, respectively upstream 4 a and downstream 4 b , each comprising a frustoconical wall and a fastening clamp 33 , 34 .

[0113] The upstream portion 4a of the housing 4 surrounds the nozzle 2. The downstream portion 4b of the housing 4 surrounds the sealing ring 10 and the impeller 5.

[0114] The two parts 4a, 4b are fastened to each other at clamps 33, 34. Each track 32, 24 extends radially inside the frustoconical wall of the first part 4a. Each track 32, 24 extends from said frustoconical wall in a downstream direction.

[0115] The radially outer end of the upstream edge 31 bears radially on the radially outer cylindrical surface of the upstream track 32 of the first portion 4a.

[0116] A portion of the downstream edge 21, for example the radially outer end 22, bears radially on a downstream track 24 of the housing 4. Specifically, the downstream edge 21 comprises an axial portion 22 extending in the upstream direction from the radial portion of said downstream edge 21, said axial portion 22 being complementary in shape to a groove 23 provided in the housing 4 and forming the downstream track 24.

[0117] The second portion 4b of the housing 4 comprises an upstream track 20 for mounting the upstream tab 18 of the sealing ring 10. Furthermore, the portion 4b of the housing 4 comprises a downstream track 26 for mounting the downstream zone of the sealing ring 10.

[0118] The upstream track 20 extends axially in the upstream direction. The downstream zone of the sealing ring 10 comprises a cylindrical surface bearing on a complementary cylindrical surface of the downstream track 26.

[0119] The sealing ring 10 comprises a radially outer support 13 , and a radially inner block 14 of abradable material fastened to the support 13 .

[0120] The sealing ring 10 is zoned. Sealing elements 36 , such as strips or foils, engage in grooves provided at the circumferential ends of the zones of the sealing ring 10 .

[0121] The sealing element 36 extends along a majority of the axial dimension of the partition, for example along at least 50%, preferably at least 80% of said axial dimension.

[0122] The sealing ring 10 comprises a radially inner surface comprising at least an upstream cylindrical zone 37 and a downstream cylindrical zone 38 , the upstream zone 37 having a smaller diameter than the downstream zone 38 .

[0123] Each blade 8 of the impeller 5 comprises an outer platform 39 from which extend radially outwards at least an upstream strip 40 and a downstream strip 41. The outer platform 39 is frustoconical and flares outwards in the downstream direction, the upstream strip 40 cooperating with the upstream cylindrical zone 37 of the sealing ring 10 and the downstream strip 41 cooperating with the downstream cylindrical zone 38.

[0124] The turbine 1 comprises at least one locking member 12 , for example several locking members 12 regularly distributed along the circumference, each locking member 12 comprising a substantially C-shaped locking area 12 a .

[0125] The locking zone 12a comprises a radially outer axial branch 42 and a radially inner axial branch 43 connected by a radial base 44. The radially outer branch 42 bears radially against the radially outer surface of the corresponding upstream track 20 of the housing 4. The radially inner branch 43 bears against the upstream tab 18 of the sealing ring 10. The inner 43 and outer 42 branches make it possible to maintain the tab 18 in contact with the corresponding upstream track 20. The base 44 bears against the upstream end 18 of the tab to press the upstream end of the tab 18 against the upstream end of the corresponding upstream track 20 of the housing 4.

[0126] The tab 18 of the sealing ring 10 includes a portion 18a extending axially in the upstream direction from the main area of ​​the sealing ring 10, and the axial portion 18a is radially supported on a corresponding upstream track 20 of the housing 4. In addition, the tab 18 includes a portion 18b extending radially outward from the upstream end of the radial portion 18a of the tab 18. The radial portion 18b is capable of supporting on the upstream end of the upstream track 20 of the housing 4.

[0127] The locking member 12 includes a positioning or centering region 12b extending radially inwardly from the locking region 12a.

[0128] The locking region 12a and the positioning region 12b are formed from a single piece, or alternatively, from at least two pieces fastened to each other. The positioning region 12b comprises a portion 45 extending radially inwardly from the locking region 12a, and cylindrical portions 46 extending axially on either side of the radially inner end of the radial portion 45.

[0129] The first annular sealing member 48 extends axially between the radial surface of the downstream edge 21 of the nozzle 2 and the positioning area 12b. The second annular sealing member 49 extends axially between the positioning area 12b and the radial surface of the sealing ring 10. The first annular member 48 and / or the second annular member 49 are elastically deformable in the axial direction. The first annular member 48 and / or the second annular member 49 have a generally ω-shaped or W-shaped cross-section.

[0130] The annular edge 50 edge extends axially in the downstream direction from the downstream edge 21 of the nozzle 2. The annular edge 51 edge extends axially in the downstream direction from the sealing ring 10. The edges 50, 51 are located radially outside the sealing members 48, 49.

[0131] The sealing ring 10 comprises a portion 52 extending axially in the upstream direction, which is at least partially located towards the sealing members 48, 49 and the locking member 12. The sealing element 36 also extends in the axial portion 52.

[0132] It should be noted that holes or apertures 21 a , 45 a and 18 c are formed in the downstream edge 21 , the radial portion 45 and the upstream tab 18 , respectively, which allow the flow of cooling or ventilation air.

[0133] The sealing components 48, 49 and the sealing element 36 ensure a seal over the entire circumference, unlike the discrete sealing components of the prior art, which are compartmentalized and do not overlap circumferentially. The sealing components and elements 48, 49, 36 also make it possible to protect the locking member 12a due to their radially inner position relative to said locking member 12a. Specifically, they make it possible to limit heating of the locking member 12a by the leakage flow of hot gases from the air flow jet 17 originating from the combustion chamber and passing through the turbine 1.

[0134] Furthermore, this structure is suitable for installing the above-listed elements of the turbine 1 via upstream.

[0135] Figure 4 A second embodiment of the present invention is shown, which is different from the above reference Figure 3 The described embodiment is characterized by the features described below.In this embodiment, the locking member 12 comprises only a C-shaped locking area 12a.

[0136] A first annular sealing member 48 extends axially between the base 44 of the locking member 12 and a radial face of the housing 4. A second sealing member 49 extends axially between a radial face of the sealing ring 10 and a radial face of the housing 4. The first sealing member 48 is received in a groove 53 of the housing 4. The first sealing member 48 and the second sealing member 49 are axially offset relative to each other.

[0137] The radially outer end of the downstream edge 21 of the nozzle 2, formed by the axial portion 22, is located radially inside the first sealing member 48, the second sealing member 49, and the locking member 12. Some portions may be scalloped, i.e., contain hollow areas, to facilitate air flow. Holes or apertures 4b and 18c are formed in the housing and upstream tab 18, respectively, which allow the flow of cooling or ventilation air.

[0138] Figure 5 A third embodiment is shown, which is different from the above reference Figure 3 and 4 The embodiment described is characterized in that an intermediate element 54 is mounted on the housing 4 downstream from the downstream edge 21 of the nozzle 2. The intermediate element 54 is positioned relative to the downstream edge 21 by means of at least one positioning or centering block 55. The intermediate element 54 extends radially. The radially outer periphery of the intermediate element 54 is fastened between radial clamps 33 of the first part 4a of the housing 4 and radial clamps 34 of the second part 4b of the housing 4.

[0139] The intermediate element 54 comprises an axial edge 56 extending in the upstream direction, bearing radially on the cylindrical surface of the housing 4 .

[0140] An annular sealing member 57 is mounted between the downstream edge 21 and the intermediate element 54. Said sealing member 57 is mounted in a groove 58 of the intermediate element 54. The first sealing member 48 and the second sealing member 49 lie in the same radial plane. If it is intended to use an ω-type seal, it is possible to place the groove in the intermediate element 54.

[0141] Formed in the intermediate element 54 and the upstream tabs 18 are holes or apertures 54 a and 18 c , respectively, which allow the flow of a cooling or ventilation air flow.

Claims

1. A turbine (1) for a turbine engine, extending along an axis, comprising an annular casing (4) and at least one turbine stage, said at least one turbine stage comprising a nozzle (2) and a rotor wheel (5) surrounded by a sealing ring (10), said sealing ring comprising an abradable element, said wheel (5) and said sealing ring (10) being located downstream of said nozzle (2), said sealing ring (10) comprising an upstream end retained on said casing (4) by a locking member, characterised in that The turbine comprises an elastic sealing member in contact with the locking member and with the nozzle or the housing (4) to press the locking member against the sealing ring (10), and wherein the locking member comprises a radial outer portion having a substantially C-shaped cross-section and a radial portion extending radially inward from the outer portion, the sealing member comprises a first elastic seal (48) and a second elastic seal (49), the two elastic seals being supported on the radial portion on either side of the radial portion, wherein the first elastic seal (48) extends axially between the nozzle (2) and the radial portion, and wherein the second elastic seal (49) extends axially between the sealing ring (10) and the radial portion.

2. The turbine (1) according to claim 1, characterized in that The first elastic seal (48) and the second elastic seal (49) comprise at least one axially deformable annular seal.

3. The turbine according to claim 1 or 2, characterized in that The locking member includes a portion having a generally C-shaped cross-section.

4. The turbine (1) according to claim 1, characterized in that The sealing ring (10) comprises a portion (52) extending axially in an upstream direction, which is located at least partially towards the locking member and / or the sealing member.

5. The turbine (1) according to claim 4, characterized in that The sealing ring (10) is zoned and comprises a plurality of zones arranged circumferentially end-to-end around an axis, with sealing elements (36) extending between ends of circumferentially adjacent ring zones.

6. The turbine (1) according to claim 5, characterized in that The sealing element (36) is located at least in a portion (52) of the sealing ring (10) extending axially in the upstream direction.

7. The turbine (1) according to claim 1, characterized in that The nozzle (2) comprises a radial outer shell (16) and a radial inner shell (15) connected by radial blades (3), the outer shell (16) comprising at least one downstream edge (21) extending radially outwards from the outer shell (16) and mounted on the housing (4), the edge (21) extending axially at least partially towards the locking member.

8. The turbine (1) according to claim 1, characterized in that The nozzle (2) comprises a radial outer shell (16) and a radial inner shell (15) connected by radial blades (3), the outer shell (16) comprising at least one downstream edge (21) extending radially outward from the outer shell (16) and mounted on the housing (4), the radial outer end of the downstream edge (21) being located radially inside the locking member.

9. The turbine (1) according to claim 1, characterized in that The sealing ring (10) comprises a tab (18) which is held in radial and axial support on a portion of the housing (4) by a locking member.

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