AIR INJECTION HOUSING FOR A TURBOMACH

Description

Technical Field

[0001] This presentation concerns turbomachine engines, and more specifically air intake housings for cooling hot parts. Previous technique

[0002] The design of ventilation circuits for an aeronautical turbomachine is delicate and represents a potential loss of performance.

[0003] Indeed, the higher the temperature at which a turbomachine operates, the more efficient it becomes. However, the materials it is made of then require more significant cooling. This cooling is generally achieved by drawing some of the air from the cold air stream, which negatively impacts overall performance.

[0004] In general, it is known to draw air for cooling radially below the combustion chamber and downstream of the last stage of the compressor disc.

[0005] The air drawn from these two sources is then mixed and routed to the blades requiring cooling. Such a cooling circuit is described in document WO 2020 / 131030.

[0006] However, such ventilation circuits have certain limitations that reduce their efficiency and decrease the overall performance of the turbomachine.

[0007] Indeed, while the air drawn radially below the combustion chamber enables the cooling cycle, it has been observed that the air drawn downstream of the last stage of the compressor disc has a low tangential velocity. However, the cooling of the rotor blades is all the more effective when the tangential velocity of the cooling air is high.

[0008] Thus, the mixing of air from these two sources reduces the overall efficiency of the cooling.

[0009] However, it is not advisable to do without the air taken downstream of the last stage of the compressor disc because the latter needs a minimum air intake in order to reduce the risk of the occurrence of the pumping phenomenon.

[0010] Thus, there remains a need for cooling architectures that ensure the air used for cooling has a higher tangential velocity than is possible with current circuits. Description of the invention

[0011] The present invention aims precisely to meet this need and, to this end, proposes a cooling air injection housing for a turbomachine according to claim 1. Such a housing has an annular shape around a longitudinal axis defining an axial direction and comprises an upstream end of the housing, a downstream end of the housing, and a main housing wall that connects the upstream end of the housing to the downstream end of the housing. The main housing wall has an annular shape with a diameter that increases from upstream to downstream. The housing further comprises: an air mixing chamber, delimited axially by the main wall of the crankcase from its upstream end and by an injector wall which extends towards the longitudinal axis from a substantially axial wall, which is connected at its upstream end to the main crankcase wall and radially delimits the air mixing chamber; an air intake chamber, delimited upstream by the injector wall and downstream by a high-pressure rotor disc of the turbomachine, the air intake chamber being in fluidic communication with the air upstream of the main crankcase wall via an air injector which has at least one injector air inlet provided in the main crankcase wall and one injector air outlet provided in the injector wall;an air purge chamber delimited by a high-pressure rotor disc of the turbomachine and a substantially radial wall connected to the main casing wall, the substantially radial wall being further connected to the substantially axial wall; a first sealing gasket separating the air mixing chamber and the air intake chamber; a second sealing gasket separating the air intake chamber and the air purge chamber; the injection housing also having an air passage housing delimited by the wall substantially radial, the main wall of the casing and the substantially axial wall, the air passage housing being in fluidic communication with the air purge housing by means of orifices provided in the substantially radial wall, characterized in that the air passage housing is in fluidic communication with the air mixing housing via orifices provided in the substantially axial wall and in that the orifices passing through the substantially axial wall have an inclination with the axial direction of between 45° and 70°.

[0012] The described housing provides improved cooling compared to housings described in the prior art.

[0013] Indeed, the fluidic communication between the air mixing housing and the air purge housing via the air passage housing and thanks to the orifices provided in the radial and axial walls advantageously allows the cooling air with a low tangential velocity to be brought out of the cooling circuit.

[0014] Indeed, during operation, the air purge housing is placed under negative pressure due to its proximity to the trailing edge of the high-pressure distributor.

[0015] Due to the fluidic communication existing between the air purge, air passage and air mixing chambers, these three chambers will be placed under negative pressure.

[0016] On the other hand, the presence of the first sealing gasket, also called the upstream sealing gasket, and the second sealing gasket, also called the downstream sealing gasket, will ensure that the air intake housing maintains a pressure higher than that of the air purge, air passage and air mixing housings.

[0017] As a result, the air taken downstream of the last stage of the compressor disc and which reaches the air mixing chamber does not pass through the first sealing gasket but passes directly to the air purge chamber via the air passage chamber.

[0018] On the other hand, the air taken in by the air inlet mouth which arrives at the air intake housing and which has a significant tangential velocity can be used for cooling, without being mixed with the air taken in downstream of the last stage of the compressor disc.

[0019] It is understood that the sealing involved is not a strict sealing in the sense that air could not pass through the sealing gasket, but a relative sealing, the purpose of the gasket being to allow a defined quantity of air to pass through.

[0020] In other words, the upstream and / or downstream sealing gaskets allow a certain pressure difference to be maintained between the air intake housing and, respectively, the air mixing housing or the air purge housing, but without completely preventing the passage of air.

[0021] For example, due to the depressurization of the air purge housing and incidentally of the air mixing housing, the air admitted into the air intake housing can pass through the upstream and / or downstream sealing joints and thus reach the air mixing and / or air purge housings.

[0022] In this application, the relative positioning terms e.g. upstream, downstream, internal and external shall be understood in relation to the horizontal axis A of the casing defining the axial direction, traversed in the direction of flow of the main and secondary airflows of the turbomachine.

[0023] Thus, an element called "upstream" will be crossed before an element called "downstream" and an element called "internal" will be closer to axis A than an "external" element.

[0024] In one embodiment, axis A can be the main axis of a turbomachine.

[0025] An element will be said to be "solid" with another, even if it is not connected to it, provided that the two elements belong to a single piece, that is to say that there is no means of fixing between the two.

[0026] Where applicable, it is specified when two elements are "linked" to each other, and it should then be understood that they have a common part.

[0027] In this application, it will be said that an element extends "substantially" in a direction if the ends of the element form an angle with said direction of less than 45°, or even less than 20°, better less than 10°.

[0028] Such a definition ensures that a wall extending "substantially along the axial direction" prevents air movement in the radial direction, without limiting the intrinsic shape of the wall, which can then be straight or not.

[0029] The cooling air injection housing according to the invention ensures that the air intake housing only receives air with a high tangential velocity, which is taken in through the air inlet opening under the combustion chamber.

[0030] Thus, it can be used for efficient cooling of the hot part of the turbomachine.

[0031] Furthermore, this embodiment makes it possible to do away with the ferrule which usually prohibits fluidic communication between the air mixing housing and the air passage housing, which is not usually accessible from either the air mixing housing or the air purge housing.

[0032] The inclination of the orifices passing through the substantially axial wall is understood in the direction away from the main axis A.

[0033] Such an inclination makes it easy to machine the holes through the substantially axial wall without requiring specific tools or special processes, and this for all the particular shapes of the main wall.

[0034] In one embodiment, the orifices through the substantially axial wall are located in the half of the substantially axial wall closest to the main wall, or even at the junction of the substantially axial wall with the main wall.

[0035] This embodiment ensures a simplified passage of air through the air passage housing to the air purge housing.

[0036] In one embodiment, the orifices passing through the substantially radial wall have an inclination with the axial direction between 45° and 85°, preferably between 70° and 83°.

[0037] This inclination is understood as an angle allowing the air to move away from the main axis.

[0038] Such an inclination of the orifices passing through the substantially radial wall allows the air to generate a minimum tangential velocity component in order to mitigate viscous heating in the air purge housing.

[0039] Preferably, it is the orifices passing through the substantially radial wall that limit the airflow through the air passage housing. In one embodiment, the opening of the orifices passing through the substantially axial wall is greater than the opening of the orifices passing through the substantially radial wall, the opening being defined here as the total surface area of ​​a wall that is removed by the orifices.

[0040] In one embodiment, the orifices passing through the substantially radial wall have a diameter between 1 mm and 5 mm.

[0041] In one embodiment, the orifices through the substantially radial wall are placed in a radially external part of the substantially radial wall.

[0042] In other words, the orifices through the substantially radial wall are located in the outermost half of the substantially radial wall.

[0043] The outermost half of the substantially radial wall is understood to be the portion of the substantially radial wall that represents half the length of the wall, furthest from the longitudinal axis. By construction, it is the half-length of the substantially radial wall closest to the main wall.

[0044] This embodiment further improves the airflow path through the air passage housing from the air mixing housing to the air purge housing. Furthermore, it allows the presence of the orifices to be integrated without having to relocate the sealing gasket that may be supported by the substantially radial wall.

[0045] In one embodiment, the first sealing joint is formed by a first part disposed on a surface of the high-pressure rotor disc, and a second part disposed on a support attached to the injector wall.

[0046] For example, the first seal is a seal that includes a sealing element mounted on the radially inner end of the injector wall.

[0047] In one embodiment, the joint is a labyrinth joint and the sealing element is an abradable sealing element.

[0048] This embodiment minimizes the amount of material needed for the air intake housing by placing an abradable sealing element on a wall that is otherwise useful to the housing.

[0049] In another embodiment, the self-adaptive sealing joint, and the sealing element is a moving part of such a joint.

[0050] In one embodiment, the second sealing joint is formed by a first part disposed on a surface of the high-pressure rotor disc and a second part disposed on the substantially axial wall.

[0051] For example, the second sealing gasket is a gasket which includes a sealing element mounted on the substantially axial wall on the side of the air intake housing.

[0052] This embodiment minimizes the amount of material needed for the air intake housing by placing the abradable cartridge on a wall that is otherwise useful for the housing.

[0053] In one embodiment, the injector wall can be substantially radial. Indeed, it provides the separation between the air mixing chamber and the air intake chamber.

[0054] In one embodiment, the injector wall can be substantially radial while also having a portion that has a component in the radial direction.

[0055] For example, the injector wall can extend from upstream to downstream and then from downstream to upstream when traversed from its inner end to its outer end.

[0056] Alternatively, it can extend from downstream to upstream and then from upstream to downstream when traversed from its inner end to its outer end.

[0057] Alternatively, it only extends from downstream to upstream or from upstream to downstream when traversed from its inner end to its outer end.

[0058] The particular geometry of the injector wall allows it to meet other wall requirements, such as good mechanical support for the air injection nozzle.

[0059] In one embodiment, the air purge housing can be arranged radially above the air intake housing.

[0060] According to another aspect, the invention also relates to an aeronautical turbomachine comprising a rotor and a cooling air injection housing as just described which extends around the rotor, the rotor comprising a high-pressure rotor disc which delimits the air intake housing and the air purge housing, the cooling air injection housing being disposed upstream of the high-pressure turbine rotor disc.

[0061] In one embodiment, the downstream end of the housing may include a mounting flange attached to a part carrying a high-pressure distributor, for example a distributor foot.

[0062] In one embodiment, the downstream end of the housing may include an attachment flange attached to a part integral with the combustion chamber, for example integral with a wall of the combustion chamber.

[0063] In one embodiment, the high-pressure turbine is a single-stage and two-stage high-pressure turbine.

[0064] It is indeed in such turbines, and in particular single-stage high-pressure turbines, that the depressurization of the purge housing allows a good diversion of air having too low a tangential velocity component thanks to an injection housing described above. Brief description of the drawings

[0065] [ Fig. 1 ] There figure 1 schematically represents a turbomachine. Fig. 2 ] There figure 2 represents the cooling path of a turbomachine according to the prior art. Fig. 3 ] There figure 3 represents a turbomachine equipped with an air injection housing according to the invention. Fig. 4 ] There figure 4 represents, from a first viewpoint, a cooling air injection housing according to the invention. Fig. 5 ] There figure 5represents, from a second viewpoint, a cooling air injection housing according to the invention, identical to that of the figure 4 . [ Fig. 6 ] There figure 6 represents details of an air injection housing in an embodiment identical to that of the figure 3 . Description of the implementation methods

[0066] The invention is now described by means of figures, which are provided for descriptive purposes to illustrate certain embodiments of the invention and which shall not be construed as limiting the invention. In particular, the figures are not drawn to scale, nor even to a relative scale.

[0067] There figure 1represents, in cross-section along a vertical plane passing through its main axis A, a turbofan engine 1. It comprises, from upstream to downstream along the airflow circulation, a fan 2, a low-pressure compressor 3, a high-pressure compressor 4, a combustion chamber 5, a high-pressure turbine 6 and a low-pressure turbine 7.

[0068] There figure 2 represents a cooling circuit according to a prior art architecture.

[0069] In such a cooling circuit, the path of the air is represented by arrows.

[0070] As shown, the cooling air can come partly from a sampling 401 taken downstream of the last disc of the high-pressure compressor and also via an air intake mouth present under the combustion chamber 5 taking in air 83.

[0071] However, as explained above, mixing these two air streams 401 and 83 in an air intake housing 42 to form the cooling stream 82 does not offer complete satisfaction, because the cooling air then has a fairly low tangential velocity, which reduces its cooling properties.

[0072] There figure 2 also represents the air purge path 81 located between the high pressure distributor 601 and the first moving blade 602 of the high pressure turbine 6, as well as the upstream 51 and downstream 52 sealing joints delimiting the air intake housing 42.

[0073] There figure 3 represents a cooling circuit in which the cooling air injection housing is as described.

[0074] In particular, it includes: an air mixing chamber 41, delimited axially by the main wall of the housing 30 from its upstream end 30a and by an injector wall 31 integral with the main housing wall which extends towards the longitudinal axis A, the injector wall 31 being connected to a substantially axial wall 32 which radially delimits the air mixing chamber 41; an air intake chamber 42, delimited upstream by the injector wall 31 and downstream by a high-pressure rotor disc 600, the air intake chamber 42 being in fluidic communication with the air upstream of the main housing wall 30 via an air injector which has at least one injector air inlet 50 provided in the main housing wall 30 and an injector air outlet provided in the injector wall 31;an air purge chamber 44 delimited by a high-pressure rotor disc 600 and a substantially radial wall 33 connected to the main housing wall 30, the substantially radial wall 33 being further connected to the substantially axial wall 32; a first sealing gasket 51 separating the air mixture chamber 41 and the air intake chamber 42, the first sealing gasket being formed by a first part 51a disposed on a surface of the high-pressure rotor disc 600, and a second part 51b disposed on a support integral with the injector wall; a second sealing gasket 52 separating the air intake chamber and the air purge chamber, the second sealing gasket being formed by a first part 52a disposed on a surface of the high-pressure rotor disc 600 and a second part 52b disposed on the substantially axial wall; the injection housing further having an air passage housing 43 delimited by the substantially radial wall 33, the main housing wall 30 and the substantially axial wall 32, the air passage housing 43 being in fluidic communication with the air mixing housing 41 via orifices 62 provided in the substantially axial wall 32, and in that the air passage housing 43 is in fluidic communication with the air purge housing 44 by means of orifices provided in the substantially radial wall 63.

[0075] Thanks to the air passage housing 43 which allows fluid communication between the air purge housing 44 and the air mixing housing 41, the air 401 which is taken downstream of the last disc of the high pressure compressor 4 does not reach the air intake housing 42.

[0076] Indeed, in operation, the air purge housing 44 is under negative pressure relative to the air intake housing 42. This negative pressure is ensured by the position of the purge path 96 between the distributor 601 and the first rotor disc 602 of the high-pressure turbine 6.

[0077] The fluidic communication ensured between the purge housing 44 and the air mixing housing 41 via the air passage housing 43 ensures the passage of the air 401 having a low velocity directly from the air mixing housing 41 to the air purge housing 44, according to the path 95.

[0078] The cup of the figure 3 This does not allow for a precise representation, but the air inlet opening does not impede air circulation in the air mixing chamber 41, as it merely passes through it. The three-dimensional position of the air inlet opening will be more easily understood in relation to the figures 4 And 5and we will then better understand how route 95 exists.

[0079] Only the air admitted through the air intake inlet in the air intake housing 42, which has a significant tangential velocity, can be admitted into the cooling circuit 92.

[0080] Indeed, the existing depression is sufficient to circulate air from the air intake housing 42 to the air mixing housing 41, along path 94, and no longer the reverse as was the case in prior art cooling circuits, as shown in figure 2 .

[0081] Also, the upstream sealing joints 51 and downstream 52 ensure sufficient sealing of the air intake housing 42 so that the latter remains under positive pressure compared to the air mixing housing 41, air passage 43 and air purge 44.

[0082] In the embodiment shown in the figure 3, the upstream 51 and downstream 52 sealing joints are labyrinth joints formed by an assembly between strips 51a, 52a arranged opposite an abradable material 51b, 52b for example in the form of honeycombs.

[0083] For example, the casing can be manufactured using additive manufacturing.

[0084] In one embodiment, the abradable 51b, 52b can be a bonding of several metal sheets together, the whole then being attached to the housing.

[0085] In one embodiment, the orifices 62 provided in the substantially axial wall 32 allow a greater air flow than the orifices 63 provided in the substantially radial wall 33.

[0086] In other words, it is the orifices 63 made in the substantially radial wall 33 that limit the flow of air passing through the air passage housing 43.

[0087] The comparison of the figure 2 and of the figure 3It further illustrates an additional advantage of the invention, which is the absence of the ferrule used to delimit the air inlet opening, thus ensuring a reduced weight of the air intake housing.

[0088] On the figure 3 , the sealing joint 53 through which the air flow 401 passes from the last stage of the high-pressure compressor 4 (also called CDP joint for the English acronym "compressor discharge pressure") is a so-called self-adapting sealing joint, comprising two parts 53a and 53b.

[0089] Such a seal differs from lip seals in that it has a mode of operation in which the seal clearance is adapted by the dynamic behavior of said seal.

[0090] The use of such seals already makes it possible to reduce the amount of air taken upstream 401, which reduces the purge flow 96 and therefore increases the overall efficiency of the turbine.

[0091] This embodiment is advantageous because the clearance allowed by such seals is less than that of flap seals, which reduces the air flow reaching the air mixing chamber and facilitates its depressurization.

[0092] In other embodiments, the sealing joints 52 and / or 53 can also be such dynamic sealing joints, also called self-adaptive sealing joints.

[0093] In the embodiment shown, the injector wall 31 is not strictly radial, but is substantially radial in the sense of the invention.

[0094] In one embodiment, which is shown, the substantially axial walls 32 and substantially radial walls 33 are strictly axial and radial, that is to say they are strictly straight.

[0095] In other embodiments, they may have a shape different from a straight shape provided that they remain respectively substantially axial and radial.

[0096] The particular shape of the injector wall 31 is not limiting of the invention provided that this wall 31 prohibits the passage of air in the axial direction between the air mixing chambers 41 and the air intake chambers 42, which it defines.

[0097] In the embodiment shown, the injector wall 31 extends from upstream to downstream and then from downstream to upstream when traversed from its inner end to its outer end, but this is not necessary.

[0098] THE figures 4 And 5 represent an air intake housing in an embodiment of the invention, under two distinct views.

[0099] In the embodiment shown, the first sealing joint 51 is a labyrinth seal whose abradable cartridge 51b is fixed on the inner end of the injector wall 31.

[0100] In the embodiment shown, the second sealing joint 52 is a labyrinth seal whose abradable cartridge 52b is fixed on the substantially axial wall 32 on the side of the air inlet housing 42.

[0101] There figure 5 also allows to be shown the inclination a of the orientation of the orifices 62 passing through the substantially axial wall 32.

[0102] The inclination a is measured relative to the axis A of the turbomachine and, according to the invention, this inclination is between 45° and 70°.

[0103] In the embodiment shown, the orifices 62 passing through the second wall 32 are located at the junction of the substantially axial wall 32 with the main wall 30.

[0104] This embodiment ensures excellent airflow from the air mixing housing 41 to the air purge housing 44 via the air passage housing 43.

[0105] In an embodiment other than the one shown, the orifices 63 passing through the substantially radial wall 33 can also be inclined with respect to the axis A of the turbomachine.

[0106] For example, the orifices 63 may have an inclination with the axial direction between 45° and 85°, preferably between 70° and 83°.

[0107] Preferably the inclination is in the direction of the tangential component of the incident air, that is to say in the direction of rotation of the rotor.

[0108] On the figure 6 , an embodiment of an air injection housing, already visible in figure 3 is depicted in greater detail.

[0109] The air injection housing and the cooling air path shown by arrows 401, 92, 93, 94, 96 are visible.

[0110] In the embodiment shown, the upstream end of the housing 30a includes a mounting flange 330a; the element to which it is attached is not shown here. This element may, however, be integral with a wall of the combustion chamber, as was also visible in the wider view in figure 3 .

[0111] In the embodiment shown, the downstream end of the housing 30b includes an attachment flange 330b. This flange can be attached to a foot 601a of the distributor 601.

[0112] On the representation of the figure 6, we can also see that the parts 51a and 52a of the sealing joints 51 and 52, useful for the separation between the air intake housings 42 and respectively the air mixing housing 41 and the air purge housing 44 are carried by the rotor 600 of a high pressure turbine.

[0113] Also, the figure 6 illustrates, if necessary, that a ferrule 35 can axially delimit the air mixing housing and conduct the air 401 from the intake after the last moving disc of the high-pressure compressor to the mixing housing 42.

[0114] In one embodiment, an element of the rotor, for example a ferrule 35, radially delimits, as close as possible to the axis A, the air mixture housing.

[0115] There figure 6The dotted line illustrates that the air path 95 from the air mixing chamber 41 to the air purge chamber 44 via the air mixing chamber 43 is not blocked by the air inlet opening. Indeed, although the two-dimensional representation of the opening on the figures 3 Or 6 suggests that communication is not possible, the three-dimensional representations to figures 4 And 5 clearly show that air 95 can circulate around the mouth.

[0116] Furthermore, the representation of the figure 6 represents only one opening, but it is preferable for the injector to include a plurality of them, distributed angularly around the main axis of the housing.

[0117] We can still see on the figure 6that the air intake housing 42 is in fluidic communication with a cooling housing 48, via an opening provided in the rotor disc 600 carrying the moving blade 602 of the high-pressure turbine.

[0118] This housing 48, in fluidic communication with the air intake housing 42, ensures that the cooling air entering this housing 48, and coming from the air 93 taken from under the combustion chamber by means of the air inlet mouth, ensures that the air used for cooling the hot parts 92 has a significant tangential velocity, which ensures better cooling of the parts.

Claims

1. A cooling-air injection casing (100) for turbomachine, the casing having an annular shape around a longitudinal axis (A) defining an axial direction (DA) and comprising a casing upstream end (30a), a casing downstream end (30b) and a casing main wall (30) which connects the upstream casing end with the downstream casing end, the casing main wall (30) having an annular shape with a diameter that increases from upstream to downstream, the casing further comprising: - an air mixing cavity (41), bounded axially by the casing main wall from its upstream end (30a) and by an injector wall (31) which extends toward the longitudinal axis (A) from a substantially axial wall (32) whose upstream end is connected to the casing main wall (30) and which radially bounds the air mixing cavity; - an air intake cavity (42), bounded upstream by the injector wall (31) and downstream by a high-pressure rotor disk (600) of the turbomachine, the air intake cavity (42) being in fluid communication with the air upstream of the casing main wall (30) via an air injector which has at least one air injector inlet (50) made in the casing main wall (30) and an air injector outlet made in the injector wall (31); - an air bleeding cavity (44) bounded by a high-pressure rotor disk (600) of the turbomachine and a substantially radial wall (33) connected to the casing main wall (30), the substantially radial wall (33) being further connected to the substantially radial wall (32); - a first sealing gasket (51) separating the air mixing cavity (41) and the air intake cavity (42); - a second sealing gasket (52) separating the air intake cavity (42) and the air bleeding cavity (44); the injection casing further having an air passage cavity (43) bounded by the substantially radial wall (33), the casing main wall (30) and the substantially axial wall (32), the air passage cavity (43) being in fluid communication with the air mixing cavity (41) via apertures (62) made in the substantially axial wall (32), and in that the air passage cavity (43) is in fluid communication with the air bleeding cavity (44) by means of apertures made in the substantially radial wall (63) and wherein the apertures passing through the substantially axial wall (32) have an inclination (α) to the axial direction (DA) comprised between 45° and 70°.

2. The cooling-air injection casing (100) according to claim 1, wherein the apertures passing through the substantially axial wall (32) are located at the junction of the substantially axial wall with the main wall (30).

3. The cooling-air injection casing (100) according to any one of claims 1 or 2, wherein the apertures (63) passing through the substantially axial wall (33) have an inclination to the axial direction (DA) comprised between 45° and 85°.

4. The cooling-air injection casing according to any one of claims 1 to 3, wherein the apertures passing through the substantially radial wall (33) have a diameter comprised between 1 mm and 5 mm.

5. The cooling-air injection casing (100) according to any one of claims 1 to 4, wherein the apertures passing through the substantially radial wall (33) are placed in a radially external portion of the substantially radial wall (33).

6. The cooling-air injection casing (100) according to any one of claims 1 to 5, wherein the first sealing gasket (51) is a sealing gasket that comprises a sealing element (51b) mounted on the radially internal end of the injector wall (31).

7. The cooling-air injection casing (100) according to any one of claims 1 to 6, wherein the second sealing gasket (52) is a sealing gasket which comprises a sealing element (52b) mounted on the substantially axial wall (32) on the side of the air intake cavity (42).

8. An aeronautical turbomachine comprising a rotor (600) and a cooling-air injection casing according to any one of claims 1 to 7 which extends around the rotor, the rotor comprising a high-pressure rotor disk (600) which bounds the air intake cavity (42) and the air bleeding cavity (44), the cooling-air injection casing being located upstream of the high-pressure turbine rotor (6).

9. The aeronautical turbomachine according to claim 8, wherein the high-pressure turbine (6) is a single-stage or two-stage high-pressure turbine.