AIRCRAFT TURBOMACHINE TURBINE STATOR ASSEMBLY, WITH ENHANCED EFFICIENCY STATOR BLEED AIR FLOW

Abstract

The invention relates to a stator assembly (12A) for an aircraft turbomachine turbine, comprising a distributor (30) and a structure (40) for supporting a seal element (46), the distributor comprising a foot (41), and a radially internal platform (32) from which distributor blades (14) extend, the support structure (40) being mounted on the foot (41) of the distributor using mounting means allowing relative movement, in a radial direction (R) of the assembly, between the foot (41) and the support structure (40), the latter comprising a first flange (43a) for connection with the foot (41), delimiting between them a flow path (62) for a stator purge air flow (64). According to the invention, the assembly comprises, on at least one delimiting surface (36, 70) of the flow path (62), deflectors (76) for directing the purge air flow. Figure for the abstract: Fig. 3

Description

Title of the invention: STATOR ASSEMBLY OF AN AIRCRAFT TURBOMACHINE TURBINE, HAVING A STATOR PURGE AIR FLOW WITH ENHANCED EFFICIENCY Technical field

[0001] The present invention relates to an aircraft turbomachine, preferably of the turbojet or turboprop type.

[0002] More particularly, the invention relates to a turbine stator assembly, configured to be subjected to a purge air flow, intended to limit the risks of ingestion of hot gases from the stream into a purge cavity. More precisely, the design concerned is that allowing free expansion in the radial direction, between a turbine distributor foot, and a support structure of a sealing element, such as a labyrinth seal. Such a turbomachine design is for example known from document FR 3 027 343 A1. State of the prior art

[0003] Within a stage of an aircraft turbomachine turbine, the stator assembly and the movable wheel which follow one another together delimit a bleed air cavity. This bleed air cavity is generally supplied by a main bleed air flow, following the movable wheel. Due to viscous friction between the movable wheel and the main bleed air flow which circulates radially outwards, this flow is also driven by a rotational movement, that is to say it has a displacement speed with a tangential component. The drive coefficient, usually called "Ke", is generally of the order of 0.4 to 0.5.

[0004] The observed tangential component makes it possible to apply a gyration movement to the main purge air flow. This gyration is in the same direction as that of the hot flow passing through the distributor blades, which makes it possible to reduce the disturbance caused by this reintroduction of purge air into the hot flow. This disturbance is also known as “mixing losses”.

[0005] Nevertheless, there is a constant need to improve the purge function, in order to further limit the risks of introducing hot gases, and / or to limit the air samples necessary to carry out this function. Statement of the invention

[0006] To meet this need, the invention firstly relates to a stator assembly for an aircraft turbomachine turbine extending around a longitudinal axis, the assembly comprising a distributor and a structure for supporting a sealing element, the distributor comprising at least one distributor blade distributor, a foot, and a radially internal platform from which the distributor blade extends radially outwardly, the foot extending radially inwardly from the radially internal platform, the support structure being mounted on the foot of the distributor using mounting means allowing relative movement, in a radial direction of the assembly, between the foot and the support structure, the latter comprising a first connecting flange with the foot of the distributor, the first flange and the foot delimiting between them a flow path for a stator purge air flow intended to supply a purge air cavity.

[0007] According to the invention, the assembly further comprises, on at least one surface delimiting the flow path, deflectors for directing the stator purge air flow, the deflectors being arranged circumferentially adjacent to each other around the longitudinal axis.

[0008] The solution provided by the invention has the advantage of remaining simple in design, easy to produce, and the advantage of which is to limit the risks of injection of hot gases from the vein into the purge cavity.

[0009] Indeed, studies have made it possible to highlight that on designs of stator assemblies allowing free expansion in the radial direction between the foot of the distributor, and the support structure of a sealing element, a stator purge air flow traveling through the interface between these two parts was the cause of a degradation of the purge function. In this regard, it is firstly noted that due to the non-rotating nature of this assembly, the speed of the stator purge air flow, traveling through this interface, does not have a tangential component. In addition, the studies carried out have shown that this stator purge air flow causes turbulence within the purge cavity, into which this flow is introduced. Such turbulence increases the risks of ingestion of hot gases from the primary flow, into the purge cavity.These turbulences also negatively impact the flow of the primary flow in the vein, leading to a drop in turbine efficiency.

[0010] Also, the presence of the deflectors for directing the stator purge air flow, on the aforementioned flow path, makes it possible to channel this air introduced into the purge cavity, and thus greatly limit the aforementioned turbulence.

[0011] By increasing the purge efficiency, the purge air draws can be reduced, which contributes to improving the overall efficiency of the turbine and the turbomachine. As such, the invention aims to improve the performance of aircraft, and, in this sense, contributes to reducing the environmental impact of these aircraft (decarbonization).

[0012] Finally, it is noted that the cooling efficiency is also increased due to the acceleration of the stator purge air flow, by the deflectors. These contribute also to increase the exchange surface with the purge air, which promotes convection cooling.

[0013] Preferably, the invention also provides at least one of the following additional optional characteristics, taken individually or in combination.

[0014] Preferably, the deflectors are inclined so as to allow the stator purge air flow to rotate around the longitudinal axis. This solution makes it possible to further limit the risks of injection of hot gases from the vein into the purge cavity. This improvement in the purge function comes from the rotation of the stator purge air flow. Indeed, this rotation can be used to reduce the formation of vortices resulting from Kelvin-Helmholtz instabilities, since the gradient of values ​​of the tangential components of the speeds of the stator purge flow and of the main purge flow is advantageously reduced. The reduction of these vortices also further promotes better flow of the primary flow in the vein, resulting in better turbine efficiency.This improvement is also explained by the fact that the gyration of the mixed purge air flow, which escapes from the purge cavity, proves to be even better adapted to the gyration of the hot flow passing through the distributor blades. This makes it possible to reduce as much as possible the disturbance caused by this introduction of purge air into the hot flow, and therefore to greatly limit mixing losses.

[0015] Preferably, the deflectors are arranged:

[0016] - on a downstream surface of the distributor foot, possibly extending onto a radially inner surface of the radially inner platform; and / or

[0017] - on an upstream surface of the first connecting flange; and / or

[0018] - on the radially inner surface of the radially inner platform (32), with a radially inner end of the deflectors preferably carrying a flow path delimiting fairing.

[0019] Preferably, the first connecting flange delimits, with its downstream surface, a part of the purge air cavity.

[0020] Preferably, the support structure comprises a second connecting flange defining with the first flange a gap receiving the distributor foot, the gap allowing the aforementioned relative movement, in the radial direction of the assembly.

[0021] Preferably, the sealing element carried by the support structure is an abradable element, preferably a labyrinth seal.

[0022] Preferably, the deflectors are arranged circumferentially adjacent to each other around the longitudinal axis, in a regular manner according to a spacing pitch.

[0023] The invention also relates to a turbine stage of an aircraft turbomachine, comprising a stator assembly as described above, preferably a high pressure assembly, as well as a turbine wheel configured to rotate in a direction of rotation, the stage also comprising a flow path for a main purge air flow, delimited at least in part by the turbine wheel.

[0024] Preferably, the direction of rotation of the moving wheel is identical to a direction of rotation of the stator purge air flow, applied by the deflectors of the stator assembly.

[0025] Finally, the invention relates to an aircraft turbomachine comprising a turbine equipped with at least one such turbine stage.

[0026] Other advantages and characteristics of the invention will appear on reading the detailed, non-limiting description which follows. Brief description of the drawings

[0027] The following detailed description refers to the attached drawings in which:

[0028] [Fig.l] is a schematic axial sectional view of a turbojet according to the invention

[0029] [Fig.2] is an axial sectional view of a portion of a turbine stage of the tur machine shown in the preceding figure, the turbine stage being in the form of a preferred embodiment of the invention;

[0030] [Fig.3] is a perspective view of a portion of the turbine stage shown in the [Fig.2] ;

[0031] [Fig.4] is an axial schematic view of part of a stator assembly ap leaving the turbine stage shown in Figures 2 and 3;

[0032] [Fig.5] is a schematic view from below of the part of the stator assembly shown in [Fig.4];

[0033] [Fig.6] is a perspective view similar to that of [Fig.3], according to an al alternative;

[0034] [Fig.7] is a perspective view similar to that of [Fig.6], according to another al alternative;

[0035] [Fig.8] is a perspective view similar to that of [Fig.7], from another angle from view, and with a cowling associated with the orientation deflectors of a stator purge air flow;

[0036] [Fig.9] is a perspective view similar to that of [Fig.3], with the floor of turbine in the form of another preferred embodiment of the invention; and

[0037] [Fig. 10] is an axial schematic view of a part of a stator assembly belonging to the turbine stage shown in [Fig.9]. Detailed description of embodiments

[0038] The figures include a reference frame L, R and C respectively defining longitudinal, radial and circumferential directions orthogonal to each other, these directions corresponding to those of an aircraft turbojet 1 according to the invention.

[0039] [Fig.l] shows the aircraft turbojet engine 1, preferably having a twin-spool, twin-flow design. However, other types of turbojet engines are possible, as are turbomachines other than turbojet engines.

[0040] Subsequently, the terms “upstream” and “downstream” are defined with respect to a main direction DI of flow of the gases through the turbojet engine 1, when the latter is in direct thrust operation. The direction DI is parallel to the longitudinal direction L, and also parallel to a longitudinal axis A1 of the turbojet engine, around which its various components extend. In this case, from upstream to downstream of the turbojet engine 1, these are a fan 4, a low-pressure compressor 5, a high-pressure compressor 6, a combustion chamber 7, a high-pressure turbine 8 and a low-pressure turbine 9.

[0041] During operation of the turbojet engine 1, an air flow 10 enters the turbojet engine 1 through an air inlet 3, passes through the fan 4, and then divides into a central primary flow 10A and a secondary flow 10B. The primary flow 10A flows in a main gas circulation vein 11A passing through the compressors 5 and 6, the combustion chamber 7, and the turbines 8 and 9. The secondary flow 10B flows in a secondary vein 11B surrounding the main vein 11A, also called the primary vein, or aerodynamic flow vein.

[0042] In a manner known per se, a turbine such as the high-pressure turbine 8 or the low-pressure turbine 9 comprises one or more stages 12, each stage comprising a stator assembly 12A comprising a distributor 30, also called a stator bladed ring, and a moving wheel 12B, arranged directly downstream of the assembly 12A. Such a stage 12 is shown in FIGS. 2 to 5.

[0043] The distributor 30 of the stage comprises distributor vanes 14, therefore stator vanes, configured to deflect the primary flow 10A coming from the combustion chamber 7 towards vanes 16 of the movable wheel 12B of the same stage, so as to drive this movable wheel in rotation around the axis A1, in a direction of rotation SL. For each of the turbines 8 and 9, the distributor(s) form a stator of the turbine, while the movable wheel(s) form a rotor of the turbine. In the following, the invention will be described in a case of installation within any one of the turbines 8 and 9, and within any one of the stages thereof, even if a preferred application lies in the high-pressure turbine, and preferably in the most upstream stages of this turbine.

[0044] The stator assembly 12A according to the invention, also centered on the longitudinal axis A1, has a generally annular shape. It therefore comprises the distributor 30, also of general annular shape, for example being obtained by the end-to-end assembly of several angular distributor sectors, in the circumferential direction C.

[0045] The distributor 30 here comprises several distributor vanes 14, as well as a radially internal platform 32, from which these vanes 14 extend radially outwards, and which follow one another in the circumferential direction C. The platform 32 has a radially external surface 34 which delimits the primary vein 11A, radially inwards. It also has a radially internal surface 36, which partly delimits a purge air cavity 38, the radially external end of which communicates radially with the primary vein 11A. The platform 32 comprises an upstream spoiler 35, as well as a downstream spoiler 37 delimiting this radially external end of the purge air cavity 38.

[0046] The distributor 30 may also comprise a radially external platform (not visible in the figures), arranged at the end of the blades, and which delimits the primary vein 11A radially outwards, so that the blades 14 extend radially between the two platforms of the distributor.

[0047] Finally, the distributor 30 comprises a foot 41 which extends radially inwards from the platform 32. This foot 41 can be made in one piece with the platform 32, or fixedly attached thereto. It has the shape of a ring centered on the axis A1, and extends in a plane orthogonal to this axis.

[0048] The assembly 12A comprises, in addition to the distributor 30, a structure 40 for supporting an element of a sealing joint. More precisely, the structure 40 has a radially external portion, forming a connection portion with the foot 41 of the distributor. The connection portion is produced using a first flange 43a for connection with the foot of the distributor, as well as using a second flange 43b for connection with this foot, located upstream of the first flange 43a. The two flanges 43a, 43b are centered on the axis A1, and they extend radially, parallel to the foot 41 which is inserted into a radial gap 44 receiving this foot. The two connection flanges 43a, 43b thus form, in section, a U or a bracket for fixing the foot 41 of the distributor, being open radially outwards.

[0049] The connection portion of the support structure 40 is mounted on the foot 41 of the distributor using mounting means 45, shown only schematically in [Fig. 2]. These means 45 allow relative movement, in the radial direction R of the assembly, between the foot 41 and the support structure 40. They thus allow free radial movement between these elements, in particular allowing the absorption of the effects of differential thermal expansion between them. To do this, the mounting means 45 comprise, for example, axial fixing pins and radial bores, in which the pins can slide. These means 45 thus allow a degree of freedom of translation in the radial direction R, but they block the axial and tangential positions of the foot 41 relative to the support structure 40.

[0050] At its radially internal portion, the support structure 40 carries the sealing element, here an abradable element 46 preferably in the form of a ring, and forming part of a labyrinth seal 48. This seal 48 further comprises sealing lips 50 projecting radially outwards, and contacting the abradable element 46. The lips 50 are carried by a rotor flange 52, extending axially and connecting two rotor moving wheels 12B, arranged on either side of the stator assembly 12A.

[0051] Thus, the purge cavity 38 is delimited radially inwardly by the rotor flange 52. It is also delimited axially upstream by the downstream surface of the first connecting flange 43a, and downstream by an upstream surface of a disc 54 of the movable wheel 12B of the turbine stage. Finally, it is delimited radially outwardly by a downstream portion of the surface 36 of the platform 32 of the distributor 30, as well as by an upstream portion of a radially internal platform 56 of the movable wheel 12B. Moreover, the downstream spoiler 37 of the distributor platform 32 is axially opposite an upstream spoiler 58 of the platform 56 of the movable wheel. The axial clearance between these two spoilers 37, 58 allows the introduction of purge air into the primary vein 11 A, in order to limit leaks in the primary flow as much as possible.

[0052] In this regard, it is noted that the rotor flange 52 also delimits, radially inwardly, a cooling air cavity 53 which feeds the purge cavity 38, via orifices 55 made through this flange 52. The cavity 53 is fed by air from the high or low pressure compressor, or by outside air. A main purge air flow, shown diagrammatically by the arrow referenced 57, thus circulates from the cooling air cavity 53, then through the orifices 55 in order to reach the purge cavity 38. It joins in this cavity a stator purge air flow 64, which will be described below.

[0053] Indeed, a flow path 62 of a stator purge air flow 64, also intended to supply the purge air cavity 38, is defined at least in part between the distributor foot 41, and the two connecting flanges 43a, 43b. The purge air flow 64 comes from an upstream cavity 66, delimited radially outwardly by the upstream part of the platform 32, and separated from the purge cavity 38 in particular by the labyrinth seal 48, through which an air leak is allowed downstream. The flow 64 corresponds to an air sampling at the level of one of the compressors, or to an external air sampling. It is first introduced into a first part of the flow path 62, between a downstream surface of the second upstream flange 43b, and an upstream surface of the distributor foot 4L. In this first part of the path, the air flow of purge 64 circulates radially inwards in the axial clearance between these two surfaces, before going around the distributor foot 41. Then, it joins a second part of the flow path 62, between an upstream surface 68 of the first downstream flange 43a, and a downstream surface 70 of the distributor foot 41, which is in the continuity of the surface 36 of the platform 32, via a connecting radius. In this second part of the path 62, the purge air flow 64 circulates radially outwards in the axial clearance between these two surfaces 68, 70, towards the platform 32. At its exit from the flow path 62, the purge air flow 64 mixes in the purge cavity 38 with the main purge air flow 57, before the mixture escapes towards the primary vein 1 IA via the space between the two spoilers 37, 58.

[0054] One of the particularities of this preferred embodiment of the invention lies in the fact that the downstream surface 70 of the distributor foot 41 is equipped with deflectors 76 for directing the stator purge air flow 64, these deflectors 76 being arranged circumferentially adjacent to each other, preferably regularly with a spacing pitch.

[0055] The deflectors 76 therefore make it possible to orient and channel the stator purge air flow 64, circulating along the flow path 62, before its introduction into the purge cavity 38. Each deflector 76 can be in the form of a hollow or a relief, or a combination of the two.

[0056] In this preferred embodiment which is best illustrated in Figures 3 to 5, the deflectors 76 are located in the flow path 62 axially opposite the first connecting flange 43a, but they extend radially outwardly beyond this flange, preferably up to the surface 36 of the platform 32. In addition, they may have an elbow at the junction between the foot 41 and the platform 32, to continue to extend downstream on the radially internal surface 36 of the platform 32 of the distributor.

[0057] In this preferred embodiment of the invention, the deflectors 76 have a downstream axial end located upstream of the spoiler 37. This axial downstream end of the deflectors 76 corresponds to an ejection end of the flow path 62, up to which the stator purge air flow 64 is channeled before mixing with the main purge air flow 57, in the cavity 38.

[0058] The deflectors 76 may be made so as to apply an axial or substantially axial orientation to the flow 64 escaping through the end of these deflectors 76. Nevertheless, they are preferably shaped so as to allow the gyration of the stator purge air flow 64 around this axis A1, that is to say so as to apply a non-zero tangential / circumferential component to the outlet speed of this flow 64. In addition, the gyration of the stator purge air flow 64, around the axis A1, is such that it occurs in a direction of gyration identical to a direction of rotation S1 of the 12B moving wheel.

[0059] To apply such a gyration, the inclination of the deflectors preferably begins from the first part 76a which is located axially opposite the first flange 43a, and this inclination continues on the second part 76b of the deflectors produced on the foot 41 radially between the flange 43a and the platform 32, as well as on the third part 76c of the deflectors formed on the surface 36 of the platform 32, as is best seen in Figures 4 and 5. As indicated previously, the deflectors 76 can be produced by projecting material to form reliefs, and / or by material recesses shaped so as to define deflectors, in the form of hollows. In all cases, they form an annular row of deflectors around the axis A1, being circumferentially spaced from each other.

[0060] On the first part 76a of the deflectors 76, these have a radially internal end of orientation for example radial, or substantially radial. They then extend on the first part 76a and on the second part 76b radially outwards in a curved manner, for example in an arc of a circle up to the platform 32, in order to apply a circumferential component and to obtain at least part of the desired straightening effect. More generally, the assembly formed by the first 76a and the second part 76b of each deflector 76 thus has a blade shape, with a span axis oriented orthoradially.

[0061] On the third part 76c of the deflectors 76 equipping the platform 32, these extend radially inwards from the surface 64, over a deflector height for example of the order of 1 to 2 mm. This deflector height may be identical or similar to that of the first and second parts 76a, 76b of the deflectors. The third part 76c of the deflectors 76, which runs along the radially internal surface 36 of the platform 32, may have a straight profile, or a curved aerodynamic profile.

[0062] Preferably, this third deflector part 76c is inclined relative to the longitudinal direction L and the axis A1, so as to provide the desired gyration of the stator purge air flow 64, when it enters the purge cavity 38. This way of proceeding makes it possible to improve the purge function, because the generated gyration, in the same direction of rotation S1 as the main purge air flow 57 driven by the wheel 12B, reduces the formation of vortices originating from Kelvin-Helmholtz instabilities. The ingestion of hot gases from the primary vein 11A, into the purge cavity 38, is advantageously reduced. This not only reinforces the purge function, but also improves the flow of the primary flow 10A in the vein 11A, as well as the cooling of the sensitive parts of the stator assembly, in particular the platform 32 of the distributor. The air sampling requirements of re- cooling and purging can also be reduced.

[0063] Furthermore, the rotation is in the same direction as that of the hot flow passing through the vanes 14 of the distributor, which makes it possible to reduce the disturbance caused by this introduction of purge air into the hot flow forming the primary flow 10A, and consequently to reduce the “mixing losses”.

[0064] With more specific reference to [Fig. 5], the inclination chosen is such that the deflectors 76 have an outlet angle A, defined between an outlet direction 77 of the third part 76c of this deflector, and the longitudinal direction L parallel to the axis A1. This angle A is preferably of a value greater than or equal to 30°. This outlet angle A, corresponding to the angle of inclination of these third parts of deflectors 76c, or to the outlet angle of the flow 64, is for example identical or similar to the outlet angle of the vanes 14 of the distributor. For information purposes, it is noted that this angle A also amounts to being defined between a plane of the body of the third part of the deflector, and a longitudinal plane passing through the axis A1 and crossing the deflector.

[0065] Within the annular row, any two deflectors 76 directly consecutive in the circumferential direction C, namely any two deflectors 76 circumferentially adjacent, define between them at the level of the third parts 76c a stator purge air outlet channel 78. The stator purge air flow 64 circulates through these channels 78, and escapes from the latter to be introduced into the purge cavity 38.

[0066] [Fig. 6] represents an alternative, in which the orientation deflectors 76 are produced in a slightly different manner from that described previously. Indeed, the deflectors 76 are here arranged at the outlet of the first connection flange 43b, still on the external part of the downstream surface 70 of the distributor foot 4L. They then extend over the radially internal surface 36 of the platform 32, in the manner of the deflectors described previously. In other words, in this alternative, the deflectors 76 comprise the second and third parts 76b, 76c of the previous deflectors, but not the first part 76a.

[0067] The other elements remain unchanged, and moreover, in the figures, the elements bearing the same numerical references correspond to identical or similar elements.

[0068] According to another alternative shown in Figures 7 and 8, the orientation deflectors 76 extend only on the radially internal surface 36 of the platform 32 of the distributor. They thus correspond only to the third part 76c of the deflectors described previously. The deflectors 76 here have a curved aerodynamic profile, and they can extend further downstream along the platform 32, and also be initiated further downstream, that is to say at a distance from the distributor foot 41.

[0069] Preferably, as shown in [Fig. 8], the radially internal end of the deflectors 76 may carry a fairing 80 for delimiting the flow path 62. This fairing 80 then preferably extends between the radially external end of the first connecting flange 43a, and the spoiler 37, following the surfaces 36, 70 also delimiting this flow path 62.

[0070] In this alternative, the ejection end of the flow path 62 is located closer to the spoiler 37 of the platform 32, while allowing mixing of the stator purge air flow 64 with the main purge air flow 57, before the introduction of the mixture into the primary vein 1 IA.

[0071] It is noted that in this alternative, the downstream spoiler 37 of the platform 32 is curved inwards, and it is arranged radially outwards relative to the upstream spoiler 58 of the platform of the mobile wheel 12B of the stage. Nevertheless, an arrangement of the spoilers similar to that shown in FIGS. 2 to 6 is also conceivable here, without departing from the scope of the invention.

[0072] Finally, Figures 9 and 10 show another preferred embodiment of the invention, in which the orientation deflectors 76 are produced on the upstream surface 82 of the first connecting flange 43a. The embodiment is similar to that of the first deflector part 76a described previously, in that the deflectors 76 have a radially inner end of orientation, for example radial, or substantially radial. They then extend radially outward in a curved manner, for example in an arc of a circle, to the outer radial end of the flange 43a, here forming the ejection end of the flow path 62. This makes it possible to apply a circumferential component and to obtain the desired straightening effect. More generally, each deflector 76 has a blade shape, with a span axis oriented orthoradially.

[0073] With more specific reference to [Fig. 10], the inclination chosen is such that the deflectors 76 have an outlet angle B, defined between an outlet direction 84 of this deflector, and the radial direction R. This angle B is preferably of a value greater than or equal to 30°. This outlet angle B corresponds to the angle of inclination of the deflectors 76, or to the outlet angle of the flow 64.

[0074] Of course, various modifications may be made by those skilled in the art to the invention which has just been described solely by way of non-limiting examples, and within the limits of the scope of the appended claims. For example, the technical characteristics of the different preferred embodiments, and their alternatives, are combinable and / or interchangeable.

Claims

Claims

1. Aircraft turbomachine turbine stator assembly (12A) extending around a longitudinal axis (A1), the stator assembly comprising a distributor (30) and a support structure (40) for a seal element (46), the distributor comprising at least one distributor blade (14), a root (41), and a radially inner platform (32) from which the distributor blade (14) extends radially outward, the root (41) extending radially inward from the radially inner platform (32), the support structure (40) being mounted on the root (41) of the distributor (14) using mounting means (45) allowing relative movement, in a radial direction (R) of the stator assembly, between the root (41) and the support structure (40), the support structure (40) comprising a first flange (43 a) for connection with the foot (41) of the distributor (14),the first flange (43a) and the foot (41) delimiting between them a flow path (62) for a stator purge air flow (64) intended to supply a purge air cavity (38), characterized in that the stator assembly further comprises, on at least one delimiting surface (36, 68, 70) of the flow path (62), deflectors (76) for orienting the stator purge air flow (54), the deflectors (76) being arranged circumferentially adjacent to each other around the axis (Al).,

2. Stator assembly according to any one of the preceding claims, characterized in that the deflectors (76) are inclined so as to allow the stator purge air flow (64) to rotate around the axis (Al).

3. Stator assembly according to any one of the preceding claims, characterized in that the deflectors (76) are arranged: - on a downstream surface (70) of the distributor foot (41), possibly extending onto a radially internal surface (36) of the radially internal platform (32); and / or - on an upstream surface (68) of the first connecting flange (43a); and / or - on the radially internal surface (36) of the radially internal platform (32), with a radially internal end of the deflectors preferably carrying a fairing (80) for delimiting the flow path (62).

4. Stator assembly according to any one of the preceding claims, characterized in that the first connecting flange (43a) delimits, with its downstream surface, a part of the purge air cavity (38).

5. Stator assembly according to any one of the preceding claims, characterized in that the support structure (40) comprises a second connecting flange (43b) defining with the first flange (43a) a gap (44) receiving the foot (41) of the distributor (14), the gap (44) allowing relative movement, in the radial direction (R) of the stator assembly.

6. A stator assembly according to any preceding claim, characterized in that the seal element (46) carried by the support structure (40) is an abradable element, preferably an abradable element of a labyrinth seal (48).

7. Stator assembly according to any one of the preceding claims, characterized in that the deflectors (76) are arranged circumferentially adjacent to each other around the axis (Al), regularly according to a spacing pitch.

8. Turbine stage (12) of an aircraft turbomachine, comprising a stator assembly (12A) according to any one of the preceding claims, preferably a high-pressure stator assembly, as well as a turbine wheel (12B) configured to rotate in a direction of rotation (SI), the turbine stage also comprising a flow path (64) for a main purge air flow (57), delimited at least in part by the turbine wheel (12B).

9. Turbine stage (12) according to the preceding claim, combined with claim 2, characterized in that the direction of rotation (SI) is identical to a direction of gyration of the stator purge air flow (64), applied by the deflectors (76) of the stator assembly (12A).

10. Aircraft turbomachine (1) comprising a turbine (8, 9) equipped with at least one turbine stage (12) according to claim 8 or 9.

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