AIRCRAFT TURBOMACHINE STATIC ASSEMBLY, FEATURING AN ENHANCED EFFICIENCY STATIC PURGE AIRFLOW

Abstract

The invention relates to a stator assembly (12A) of an aircraft turbomachine turbine, comprising a distributor (30) and a support structure (40) for a sealing 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 by means of mounting means allowing relative displacement, along 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 flow of stator purge air (64). According to the invention, the assembly comprises, on at least one boundary surface (36, 70) of the flow path (62), deflectors (76) for directing the purge airflow. Figure for the abstract: Fig. 3

Description

Title of the invention: STATORIC ASSEMBLY OF AN AIRCRAFT TURBOMACHINE TURBINE, FEATURING AN ENHANCED EFFICIENCY STATORIC PURGE AIRFLOW 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 risk of ingestion of hot gases from the stream into a purge cavity. More specifically, the design concerned is one allowing free expansion in the radial direction between a turbine distributor foot and a support structure for a sealing element, such as a labyrinth seal. Such a turbomachine design is, for example, known from document FR 3 027 343 A1. Prior art

[0003] Within a stage of an aircraft turbomachine turbine, the successive stator assembly and runner together define a purge air cavity. This purge air cavity is generally supplied by a main purge air flow, which follows the direction of the runner. Due to viscous friction between the runner and the main purge air flow, which flows radially outwards, this flow also undergoes rotational motion; that is, it has a velocity with a tangential component. The drive coefficient, usually denoted "Ke," is generally in the range of 0.4 to 0.5.

[0004] The observed tangential component allows a gyration to be applied to the main purge air flow. This gyration is in the same direction as that of the hot flow passing through the distributor vanes, which reduces 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 purging function, in order to further limit the risks of introducing hot gases, and / or to limit the air withdrawals necessary to carry out this function. Description of the invention

[0006] To meet this need, the invention first relates to a stator assembly for an aircraft turbomachine turbine extending around a longitudinal axis, the assembly comprising a distributor and a support structure for a sealing element, the distributor comprising at least one disc blade tributator, a foot, and a radially internal platform from which the distributor vane extends radially outwards, the foot extending radially inwards from the radially internal platform, the support structure being mounted on the distributor foot using mounting means permitting relative displacement, along a radial direction of the assembly, between the foot and the support structure, the latter comprising a first flange for connection with the distributor foot, the first flange and the foot delimiting between them a flow path for a stator purge air stream intended to supply a purge air cavity.

[0007] According to the invention, the assembly further comprises, on at least one flow path boundary surface, deflectors for directing the flow of stator purge air, 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 implement, and whose interest is to limit the risks of injecting hot gases from the vein into the purge cavity.

[0009] Indeed, studies have shown that in stator assembly designs allowing free radial expansion between the distributor foot and the support structure of a sealing element, a stator purge air flow passing through the interface between these two parts causes a degradation of the purge function. In this regard, it should first be noted that, due to the non-rotating nature of this assembly, the velocity of the stator purge air flow passing through this interface does not have a tangential component. Furthermore, 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 risk of ingestion of hot gases from the primary flow into the purge cavity.These turbulences also negatively impact the primary flow in the stream, leading to a decrease in turbine efficiency.

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

[0011] Thanks to increased purge efficiency, purge air withdrawals can be reduced, which contributes to improving the overall efficiency of the turbine and turbomachine. As such, the invention aims to improve aircraft performance and, in this respect, 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 airflow by the deflectors. These contribute Furthermore, it increases the exchange surface area with the purge air, which promotes convection cooling.

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

[0014] Preferably, the deflectors are inclined to allow the stator purge airflow to rotate around its longitudinal axis. This solution further limits the risk of hot gases from the duct entering the purge cavity. This improved purge function results from the rotation of the stator purge airflow. Indeed, this rotation can be used to reduce the formation of vortices arising from Kelvin-Helmholtz instabilities, since the gradient of the tangential velocity components of the stator purge flow and the main purge flow is advantageously reduced. The reduction of these vortices also further promotes better primary flow within the duct, resulting in improved turbine efficiency.This improvement is also explained by the fact that the rotation of the mixed purge air flow, which escapes from the purge cavity, proves to be even better adapted to the rotation of the hot flow passing through the distributor vanes. This makes it possible to minimize the disturbance caused by this introduction of purge air into the hot flow, and therefore to significantly limit mixing losses.

[0015] Preferably, the deflectors are arranged:

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

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

[0018] - on the radially internal surface of the radially internal platform (32), with an internal radial end of the deflectors preferably bearing a fairing to delimit the flow path.

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

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

[0021] Preferably, the sealing element carried by the support structure is an abradable element, preferably for 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 step.

[0023] The invention also relates to an aircraft turbomachine turbine stage, comprising a stator assembly as described above, preferably a high-pressure assembly, and a turbine wheel configured to rotate in one direction of rotation, the stage also comprising a flow path for a main purge airflow, 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 airflow, 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 features of the invention will become apparent from the following detailed, non-limiting description. Brief description of the drawings

[0027] The detailed description that follows refers to the accompanying drawings in which:

[0028] [Fig. 1] is a schematic axial cross-sectional view of a turbojet engine according to the invention

[0029] [Fig.2] is an axial cross-sectional view of part of a turbine stage of the tur bomachine represented in the previous figure, the turbine stage being in the form of a preferred embodiment of the invention;

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

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

[0032] [Fig.5] is a schematic view from below of 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 a different angle of sight, and with a hood associated with the orientation deflectors of a stator purge airflow;

[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 part of a stator assembly belonging to the turbine stage shown in [Fig.9]. Detailed description of implementation methods

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

[0039] Figure 1 represents 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] Hereafter, the terms "upstream" and "downstream" are defined with respect to a principal direction DI of gas flow through the turbojet 1 when it is operating in direct thrust mode. The direction DI is parallel to the longitudinal direction L, and also parallel to a longitudinal axis Al of the turbojet, around which its various components extend. In this case, from upstream to downstream of the turbojet 1, these components 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 the operation of the turbojet 1, an airflow 10 enters the turbojet 1 through an air inlet 3, passes through the fan 4, and then splits into a central primary flow 10A and a secondary flow 10B. The primary flow 10A flows in a main gas circulation channel 11A passing through the compressors 5 and 6, the combustion chamber 7, and the turbines 8 and 9. The secondary flow 10B, on the other hand, flows in a secondary channel 11B surrounding the main channel 11A, also called the primary channel, or aerodynamic flow channel.

[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 including a distributor 30, also called a stator bladed ring, and a runner 12B, arranged directly downstream of the assembly 12A. Such a stage 12 is shown in Figures 2 to 5.

[0043] The stage distributor 30 comprises distributor vanes 14, i.e., stator vanes, configured to divert the primary flow 10A from the combustion chamber 7 towards vanes 16 of the impeller 12B of the same stage, so as to drive this impeller in rotation about the axis Al, in a direction of rotation SL. For each of the turbines 8 and 9, the distributor(s) form a turbine stator, while the impeller(s) form a turbine rotor. In what follows, the invention will be described in the case of implementation within any one of the turbines 8 and 9, and within any one of their stages, although a preferred application lies in the high-pressure turbine, and preferably in the upstream stages of this turbine.

[0044] The stator assembly 12A according to the invention, also centered on the longitudinal axis Al, has a generally annular shape. It therefore includes the distributor 30, also of general annular shape, for example obtained by the end-to-end assembly of several angular distributor sectors, according to 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, following one another in the circumferential direction C. The platform 32 has a radially external surface 34 that delimits the primary flow 11 A, radially inwards. It also has a radially internal surface 36, which partially delimits a purge air cavity 38, the radially external end of which communicates radially with the primary flow 1 IA. The platform 32 includes 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 include a radially external platform (not visible in the figures), arranged at the end of the blades, which delimits the primary flow 11A radially outwards, so that the blades 14 extend radially between the two platforms of the distributor.

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

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

[0049] The connecting portion of the support structure 40 is mounted on the foot 41 of the distributor using mounting means 45, shown schematically only in [Fig. 2]. These means 45 allow relative movement, along 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 permitting the absorption of the effects of differential thermal expansion between them. To this end, the mounting means 45 include, for example, axial fixing pins and radial bores, in which the pins can slide. These means 45 thus allow a degree of translational freedom along 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 shape of a ring, and forming part of a labyrinth seal 48. This seal 48 further includes sealing strips 50 projecting radially outwards, and contacting the abradable element 46. The strips 50 are carried by a rotor flange 52, extending axially and connecting two movable rotor wheels 12B, arranged on either side of the stator assembly 12A.

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

[0052] In this regard, it is noted that the rotor flange 52 also radially delimits inwardly a cooling air cavity 53 which supplies the purge cavity 38 via orifices 55 formed through this flange 52. The cavity 53 is supplied with air from the high- or low-pressure compressor, or with outside air. A main purge air flow, schematically represented by the reference arrow 57, thus flows from the cooling air cavity 53, then through the orifices 55 to reach the purge cavity 38. In this cavity, it joins a stator purge air flow 64, which will be described below.

[0053] Indeed, a flow path 62 for a stator purge air stream 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 stream 64 originates from an upstream cavity 66, radially delimited outwards by the upstream part of the platform 32, and separated from the purge cavity 38 in particular by the labyrinth seal 48, through which air leakage is permitted downstream. The stream 64 corresponds to an air intake at one of the compressors, or to an outside air intake. It first enters 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 airflow of The purge air 64 flows radially inward in the axial gap between these two surfaces, before bypassing the distributor foot 41. It then joins a second section 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 continuous with the surface 36 of the platform 32, via a connecting radius. In this second section of the flow path 62, the purge air 64 flows radially outward in the axial gap between these two surfaces 68 and 70, toward the platform 32. Upon exiting the flow path 62, the purge air 64 mixes in the purge cavity 38 with the main purge air 57, before the mixture escapes toward the primary flow 1IA via the space between the two spoilers 37 and 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 flow of stator purge air 64, these deflectors 76 being arranged circumferentially adjacent to each other, preferably in a regular manner according to a spacing step.

[0055] The deflectors 76 thus allow the stator purge air flow 64, circulating along the flow path 62, to be directed and channeled 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 both.

[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 outwards beyond this flange, preferably to the surface 36 of the platform 32. In addition, they may have a bend at the junction between the foot 41 and the platform 32, to continue extending 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 downstream axial end of the deflectors 76 corresponds to an ejection end of the flow path 62, to which the stator purge airflow 64 is channeled before mixing with the main purge airflow 57, in the cavity 38.

[0058] The deflectors 76 can be made so as to apply an axial or substantially axial orientation to the flow 64 escaping from the end of these deflectors 76. However, they are preferably shaped so as to allow the rotation of the stator purge air flow 64 about this axis Al, that is to say, so as to apply a non-zero tangential / circumferential component to the outlet velocity of this flow 64. Moreover, the rotation of the stator purge air flow 64 about the axis Al is such that it occurs in the same direction of rotation as the direction of rotation SI of the movable wheel 12B.

[0059] To apply such rotation, the inclination of the deflectors preferably begins with the first part 76a, which is located axially opposite the first flange 43a, and this inclination continues over the second part 76b of the deflectors formed on the foot 41 radially between the flange 43a and the platform 32, as well as over the third part 76c of the deflectors formed on the surface 36 of the platform 32, as is most clearly seen in Figures 4 and 5. As previously indicated, the deflectors 76 can be made of protruding material to form reliefs, and / or of material recesses shaped 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 one another.

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

[0061] On the third portion 76c of the deflectors 76 equipping the platform 32, these extend radially inwards from the surface 64, over a deflector height, for example, on the order of 1 to 2 mm. This deflector height may be identical or similar to that of the first and second portions 76a, 76b of the deflectors. The third portion 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 portion 76c is inclined with respect to the longitudinal direction L and the axis Al, so as to provide the desired gyration of the stator purge airflow 64 as it enters the purge cavity 38. This method improves the purge function because the gyration generated, in the same direction of rotation SI as the main purge airflow 57 driven by the impeller 12B, reduces the formation of vortices resulting from Kelvin-Helmholtz instabilities. The ingestion of hot gases from the primary stream 11A into the purge cavity 38 is thus advantageously reduced. This not only enhances the purge function but also improves the flow of the primary stream 10A in the stream 11A, as well as the cooling of sensitive parts of the stator assembly, particularly the distributor platform 32. The air intake requirements of re- Cooling and purging can also be reduced.

[0063] In addition, the gyration 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 brought about by this introduction of purge air into the hot flow forming the primary flow 10A, and consequently to reduce the "losses by mixing".

[0064] With more precise reference to [Fig. 5], the chosen inclination 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 Al. This angle A is preferably greater than or equal to 30°. This outlet angle A, corresponding to the angle of inclination of these third parts of the 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 is also equivalent to being defined between a plane of the body of the third part of the deflector, and a longitudinal plane passing through the axis Al and traversing the deflector.

[0065] Within the annular row, two arbitrary and directly consecutive deflectors 76 in the circumferential direction C, namely two circumferentially adjacent arbitrary deflectors 76, 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 them to be introduced into the purge cavity 38.

[0066] Figure 6 represents an alternative in which the orientation deflectors 76 are made in a slightly different manner than described previously. In this alternative, the deflectors 76 are arranged at the outlet of the first connecting flange 43b, still on the outer part of the downstream surface 70 of the distributor foot 4L. They then extend over the radially inner surface 36 of the platform 32, in the same manner as 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 over the radially internal surface 36 of the distributor platform 32. They thus correspond only to the third part 76c of the deflectors described above. 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, i.e., at a distance from the distributor foot 41.

[0069] Preferably, as shown in [Fig.8], the radially internal end of the deflectors 76 can carry a fairing 80 for delimiting the flow path 62. This fairing 80 then extends preferentially 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 a mixing of the stator purge airflow 64 with the main purge airflow 57, before the introduction of the mixture into the primary channel 1 IA.

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

[0072] Finally, Figures 9 and 10 represent another preferred embodiment of the invention, in which the orientation deflectors 76 are formed on the upstream surface 82 of the first connecting flange 43a. The embodiment is similar to that of the first deflector portion 76a described previously, in that the deflectors 76 have a radially internal end with, for example, a radial or substantially radial orientation. They then extend radially outwards in a curved manner, for example in an arc, to the external radial end of the flange 43a, forming here the ejection end of the flow path 62. This allows a circumferential component to be applied and the desired straightening effect to be obtained. More generally, each deflector 76 has a blade-like shape, with a span axis oriented orthoradially.

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

[0074] Of course, various modifications can be made by a person skilled in the art to the invention just described by way of non-limiting examples, and within 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

Demands

1. A stator assembly (12A) of an aircraft turbomachine turbine extending about a longitudinal axis (Al), the stator assembly comprising a distributor (30) and a support structure (40) for a sealing element (46), the distributor comprising at least one distributor blade (14), a foot (41), and a radially internal platform (32) from which the distributor blade (14) extends radially outward, the foot (41) extending radially inward from the radially internal platform (32), the support structure (40) being mounted on the foot (41) of the distributor (14) by means of mounting means (45) permitting relative displacement, along a radial direction (R) of the stator assembly, between the foot (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) of 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 rotation of the stator purge airflow (64) 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), extending optionally 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 distributor (14), the gap (44) allowing relative displacement, along the radial direction (R) of the stator assembly.

6. Stator assembly according to any one of the preceding claims, characterized in that the sealing 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), in a regular manner according to a spacing step.

8. Aircraft turbomachine turbine stage (12), comprising a stator assembly (12A) according to any one of the preceding claims, preferably a high-pressure stator assembly, and 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 stream (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 airflow (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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