Ventilation air distributor for a turbine of an aircraft turbine engine

Abstract

The invention relates to a ventilation air distributor (50) for a turbine (10) of an aircraft turbine engine, this distributor (50) comprising: - an annular air manifold (52) extending about an axis (X), and - at least one axial extension (54) extending from the manifold (52) along the axis (X), this axial extension (54) comprising at least two ducts (64) fluidically connected to the manifold (52) and each comprising an air outlet (66) which is oriented radially outwards, the air outlets (66) of the ducts (64) being at an axial distance from each other or from one another as well as from the manifold (52).

Description

[0001] DESCRIPTION

[0002] TITLE: VENTILATION AIR DISTRIBUTOR FOR AN AIRCRAFT TURBOMACHINE TURBINE

[0003] Technical field of the invention

[0004] The present invention relates to a ventilation air distributor for an aircraft turbomachine turbine, as well as to an aircraft turbine and turbomachine comprising such a distributor.

[0005] Technical background

[0006] The technical background includes in particular documents US-A1 - 2015 / 047359, US-A1 -2015 / 285147, US-B2-10,655,475, US-A1 -

[0007] 2018 / 187550 and US-A-5,497,613.

[0008] An aircraft turbomachine typically includes at least one compressor, an annular combustion chamber, and at least one turbine. Air entering the compressor is compressed, then mixed with fuel and burned in the combustion chamber. The combustion gases are then expanded in the turbine, which rotates the turbine rotor, which in turn drives the compressor rotor.

[0009] There are several turbomachine technologies, such as turboprops or turbojets, which include, for example, a propulsion propeller located upstream of the turbomachine and which is also driven by the turbine rotor, this propeller being able to be shrouded or unshrouded.

[0010] There are also several turbomachine configurations, such as single-spool or multi-spool. In a twin-spool turbomachine, for example, the turbomachine comprises a low-pressure spool and a high-pressure spool. The low-pressure spool comprises a low-pressure compressor rotor connected by a low-pressure shaft to a low-pressure turbine rotor. The high-pressure spool comprises a high-pressure compressor rotor connected by a high-pressure shaft to a high-pressure turbine rotor. In the direction of gas flow in the turbomachine, from upstream to downstream, the twin-spool turbomachine then comprises a low-pressure compressor, a high-pressure compressor, the combustion chamber, a high-pressure turbine, and a low-pressure turbine.

[0011] A turbomachine compressor comprises one or more compression stages which extend around and along a single axis, and which each comprise a rotor wheel and a stator blade (also called a rectifier blade).

[0012] Similarly, a turbomachine turbine comprises one or more expansion stages which extend around and along the same axis, and which each comprise a rotor wheel and a stator blade (also called a distributor blade).

[0013] A turbomachine turbine is crossed by combustion gases and is exposed during operation to relatively high temperatures which have an impact on the behavior of the parts and their assembly. Optimal cooling of the turbine is therefore an important issue to guarantee an optimal service life of the turbine and the turbomachine.

[0014] In a turbine, the rotor wheels each comprise an annular disc carrying blades on its periphery. The disc of each of the rotor wheels comprises an annular flange which is fixed to an annular flange of the disc of an adjacent rotor wheel, for example by screw-nut type means. The flanges of the discs of two adjacent rotor wheels define, with these discs, annular pockets in which high temperatures prevail during operation which can be critical for the surrounding parts.

[0015] The invention provides a solution to this problem, which is simple, effective and economical.

[0016] Summary of the invention The invention relates to a ventilation air distributor for an aircraft turbomachine turbine, this distributor comprising:

[0017] - an annular air collector extending around an axis, and

[0018] - at least one axial extension extending from the collector along said axis, this axial extension comprising at least two ducts fluidically connected to the collector and each comprising an air outlet which is oriented radially outwards, the air outlets of the ducts being axially spaced from one another or from one another as well as from the collector. The distributor is particularly suitable for its integration into a turbomachine turbine. The collector can be fixed to a stator of the turbine. The air outlets are intended to be oriented towards fixing flanges of the rotor wheels of this turbine so that air collected by the collector can be conveyed by the ducts to the air outlets and be projected or injected at the flanges.The rotor wheels are mobile in rotation around the axis of the distributor and will drive in rotation the air supplied by the distributor, and in particular by the air outlets of the ducts, which will make it possible to distribute this air in particular in the aforementioned pockets to reduce their temperature. The driving of the rotating air can be facilitated by the screws or bolts fixing the flanges together. The invention thus allows the bursting of the air flows at the level of the fixing flanges to create dynamic cold air movements making it possible to circulate the flows and cool the pockets.

[0019] The dispenser according to the invention may comprise one or more of the following features, taken in isolation from one another, or in combination with one another:

[0020] - each of the conduits comprises first and second sections, the first section of each conduit extending along the axis from the collector to the second section which is bent;

[0021] - the conduits share the same first section and have second sections independent of each other; - the conduits are connected to each other or to each other, or even also to said collector, by at least one veil of material which extends in a plane passing through said axis;

[0022] - said at least one veil of material is perforated, which helps to promote the flow of air in the enclosure;

[0023] - the collector has a general C-shaped axial section and comprises an annular opening which is oriented axially on the side opposite said at least one axial extension;

[0024] - the collector comprises an internal annular fixing flange and / or an external annular fixing flange;

[0025] - at least some of the air outlets are located at different radial distances from said axis, and in particular at radial distances which increase as one moves away from said collector;

[0026] - each of the air outlets has a circular shape or an elongated shape along a circumference centered on the axis;

[0027] - at least one of said air outlets is equipped with one or more air projection nozzles;

[0028] - said at least one axial extension is fluidically connected to said collector by an axially passing orifice formed in the collector;

[0029] - the distributor comprises two or more axial extensions distributed around said axis;

[0030] - the distributor comprises two or more axial extensions distributed around said axis;

[0031] -- said at least one axial extension is non-annular.

[0032] The present invention also relates to a turbine for an aircraft turbomachine, comprising several expansion stages which extend around and along the same axis, and which each comprise a rotor wheel and a stator blading, the rotor wheels each comprising an annular disc carrying blades at its periphery, the disc of each of the rotor wheels comprising an annular flange which is fixed to an annular flange of the disc of an adjacent rotor wheel, the flanges of the discs of two adjacent rotor wheels being located between the discs of these wheels and comprising a minimum internal diameter which is greater than the minimum internal diameters of these discs, the turbine further comprising a distributor as described above which is fixed to a stator of the turbine,this distributor having its axis which is merged with the axis of the turbine and having its collector which is located upstream of the expansion stages with reference to the flow of air in the distributor from the collector to the ducts, the air outlets of the distributor being located in connecting planes of said flanges which are perpendicular to said axis.,

[0033] Advantageously, the number of ducts and air outlets is n, and the number of stages or rotor wheels of the turbine is n+1.

[0034] Preferably, the air outlets are located at radial distances from said axis which increase with distance from said collector, and the discs of the rotor wheels have internal radii which increase with distance from said collector and which are respectively less than the aforementioned distances of the air outlets arranged directly downstream of these wheels with reference to the flow of air in the distributor from the collector to the ducts.

[0035] The distributor may be mounted in an annular space located radially between the rotor wheels and a journal coupling these wheels to a turbine shaft.

[0036] The invention further relates to a turbomachine, in particular for an aircraft, comprising at least one distributor as defined above or at least one turbine as defined above.

[0037] Brief description of the figures

[0038] Other characteristics and advantages will emerge from the following description of a non-limiting embodiment of the invention with reference to the appended drawings in which:

[0039] [Fig.1] Figure 1 is a half-schematic axial sectional view of an aircraft turbomachine turbine, [Fig.2] Figure 2 is a half-schematic axial sectional view of an aircraft turbomachine turbine, this turbine being equipped with a ventilation air distributor according to one embodiment of the invention, [Fig.3] Figure 3 is a schematic perspective view of an axial extension of a ventilation air distributor according to the invention,

[0040] [Fig.4] Figure 4 is a schematic perspective view of an annular collector of a ventilation air distributor according to the invention, and

[0041] [Fig.5] Figure 5 is a schematic perspective view of an axial extension of a ventilation air distributor according to an alternative embodiment of the invention.

[0042] Detailed description of the invention

[0043] Figure 1 shows a turbine 10 of an aircraft turbomachine, for example of the double-spool type. The turbine 10 may be a low-pressure turbine, for example.

[0044] The turbine 10 comprises several expansion stages, four in number in the example shown.

[0045] The expansion stages extend around and along the same axis X. Each of the stages comprises a rotor wheel 12 and a stator blade 14 (also called a distributor blade or turbine distributor). In the example shown, the stator blade 14 is located downstream of the rotor wheel 12 with reference to the flow of gases in the turbine, but the reverse is possible.

[0046] The stator blades 14 are carried by an annular casing 16 which extends around the axis X and all the stages. Each of the stator blades 14 comprises an annular row of blades 18 which extend radially between an inner annular platform 20 and an outer annular platform 22. Each of the stator blades 14 is sectored, which means that the inner and outer platforms 20, 22 are themselves sectored. The outer platform 22 comprises hooks 23 for fixing the blade 14 to the casing 16. The inner platform 20 carries an annular cartridge 24 made of abradable material. The rotor wheels 12 are fixed to each other by clamping and form a single-piece assembly fixed by a journal 26 or the like to a turbine shaft (not shown).

[0047] The rotor wheels 12 each comprise an annular disc 28 carrying blades 30 at its periphery. The disc 28 of each of the rotor wheels 12 comprises an annular flange 32, 34 which is fixed to an annular flange of the disc 28 of an adjacent rotor wheel 12.

[0048] The disc 28 of the most upstream rotor wheel 12 has a single downstream flange 32 for attachment to the disc 28 of the rotor wheel 12 located just downstream. The discs 28 of the other rotor wheels 12 each have an upstream flange 34 and a downstream flange 32 for respective attachment to the disc 28 of the rotor wheel 12 located just upstream, and to the disc of the rotor wheel 12 located just downstream, with the exception of the disc 28 of the most downstream rotor wheel 12 which has its downstream flange 32 which is attached to the aforementioned journal 26.

[0049] The flanges 32, 34 of the discs 28 of two adjacent rotor wheels 12 are located between the discs 28 of these wheels and have a minimum internal diameter denoted D1 between the first and second stages, D1' between the second and third stages, and D1" between the third and fourth stages.

[0050] Furthermore, we note respectively D2, D3, D4, D5 the minimum internal diameters of the rotor wheels 12, and in particular of their discs 28, of the expansion stages from upstream to downstream.

[0051] We can see in the drawing that the diameters D2-D5 increase from upstream to downstream, that is to say that D2 < D3 < D4 < D5.

[0052] We also note that the diameters D1-D1' increase from upstream to downstream, that is to say that D1 < D1' < D1”.

[0053] Finally, we note that D1 is greater than D2 and D3, that D1' is greater than D3 and D4, and that D1” is greater than D4 and D5.

[0054] The flanges 32, 34 of the discs 28 of two adjacent rotor wheels 12 located between the discs 28 of these wheels 12 thus have a minimum internal diameter D1-D1” which is greater than the minimum internal diameters D2-D5 of these discs. The radii corresponding to the diameters D1-D1” and D2-D5 are respectively denoted D1 / 2, D172, D1 2, D2 / 2, D3 / 2, D4 / 2 and D5 / 2.

[0055] In the example shown, flanges 36 of annular plates 38 are interposed between the flanges 32, 34 of the discs 28. These plates 38 carry annular wipers 40 which extend radially outwards and cooperate with the aforementioned cartridges 24.

[0056] Reference 41 designates annular pockets of hot air which are located between the flanges 32, 34 and the discs 28 in operation and which are likely to reach significant and excessive temperatures for the surrounding parts in operation.

[0057] U defines connecting planes of the flanges 32, 34, which are perpendicular to the axis X and which pass between the flanges 32, 34 and for example at the level of the flanges 36 of the plates 38. U1 is the connecting plane of the flanges 32, 34 between the discs 28 of the first and second stages, U2 is the connecting plane of the flanges 32, 34 between the discs 28 of the second and third stages, and U3 is the connecting plane of the flanges 32, 34 between the discs 28 of the third and fourth stages.

[0058] The turbine 10 may comprise upstream an annular stator 42 centered on the axis X. In the example shown, the stator 42 has its external periphery which is connected to the internal periphery of another turbine distributor 44 located upstream of the expansion stages and which may be part for example of a high pressure turbine. The internal periphery of the stator 42 is connected to an annular cartridge 46 of abradable material which surrounds the lips 48 of another flange 49 integral in rotation with the journal 26.

[0059] Figures 2 to 4 illustrate an embodiment of a ventilation air distributor 50. Essentially, this distributor 50 comprises two parts, namely an annular collector 52 and at least one axial extension 54.

[0060] In the example shown, the distributor 50 is mounted in the annular space located radially between the rotor wheels 12 and the journal 26. Figure 2 shows the turbine 10 of Figure 1 equipped with the distributor 50, and Figures 3 and 4 show respectively the axial extension 54 and the collector 52 of this distributor 50.

[0061] The collector 52 has an annular shape around an axis which is the X axis when the distributor 50 is mounted in the turbine 10.

[0062] The distributor 50 is intended to be fixed to a stator of the turbine 10, preferably via its collector 52. The distributor 50 is preferably fixed to the stator by a flexible connection, in order to allow differential expansions of the parts in operation. This flexibility can be provided by the geometry of the collector. Its curved shape can allow it to deform without breaking within the limits of the characteristics of the elastic resistance of its material.

[0063] By definition, the manifold 52 has an air collection function but also a function of supplying air to the axial extension 54 which is fluidically connected to the manifold 52.

[0064] In the example shown, the collector 52 has a general C-shaped axial section and comprises an annular opening 56 which is oriented axially on the side opposite the axial extension 54 or the axial extensions. The opening 56 is intended to be oriented upstream to collect the air upstream, and the or each axial extension 54 is intended to be oriented downstream to distribute this air downstream.

[0065] In the example shown, the collector 52 is fixed to the stator 42. The collector 52 may comprise one or more annular fixing flanges. In the example shown, it comprises an internal annular fixing flange 58, in particular to the element carrying the abradable cartridge 46 of FIG. 1, and an external annular fixing flange 60 to the distributor 44 or to an intermediate annular part located between the collector 52 and this distributor 44.

[0066] The flanges 58, 60 may be continuous over 360° or include radial notches, or be scalloped, as illustrated in Figure 4. These flanges 58, 60 include axial orifices for the passage of fixing means of the screw or bolt type for example.

[0067] The collector 52 can be sectored or formed from a single piece.

[0068] The manifold 52 may include at least one axially oriented port 62 for fluid connection to the or each axial extension 54. The port 62 may be formed in a sector of the manifold 52 that is integral or integrally formed with one or both axial extensions 54, as shown in Figure 3.

[0069] The following description relates to an axial extension 54 but applies to each axial extension of the distributor 50 in the event that the latter comprises several.

[0070] The axial extension 54 extends from the collector 52 along the X axis.

[0071] The axial extension 54 comprises at least two conduits 64 fluidly connected to the collector 52 and each comprising an air outlet 66 which is oriented radially outwards.

[0072] In the example shown, the axial extension 54 comprises three ducts 64. In the case where the number of stages of the turbine 10 is denoted N, it is understood that the number of ducts 64 of the distributor 50 is N-1. In other words, the number of ducts 64 and air outlets 66 is n, and the number of stages or rotor wheels 12 of the turbine 10 is n+1.

[0073] The air outlets 66 of the ducts 64 are axially spaced from one another or from one another as well as from the collector 52, that is to say that the air outlets 66 are distributed regularly or not along the axis X.

[0074] The distributor 50 thus has a general shape of a comb with several branches. Each of the conduits 64 comprises first and second sections 64a, 64b. The first section 64a of each conduit 64 extends along the axis X from the collector 52 to the second section 64b which is bent.

[0075] The conduits 64 may share the same first section 64a and have second sections 64b independent of each other.

[0076] The ducts 64 may be connected to each other, or even to the collector 52, by at least one web of material 68 which extends in a plane P1 passing through the axis X. The or each web 68 may have a function of stiffening the axial extension 54 and the collector 52. The ducts 54 may have different internal sections to adapt to potential aerodynamic pressure losses.

[0077] In the example shown, a first web 68a extends in the plane P1 between the collector 52 and a first conduit 64 whose outlet 66 is located furthest upstream, a second web 68b extends in the plane P1 between the first conduit 64 and the second conduit 64 whose outlet 66 is located just downstream of that of the first conduit 64, and a third web 68c extends in the plane P1 between the second conduit 64 and the third conduit 64 whose outlet 66 is located furthest downstream.

[0078] The or each material veil 68 may be perforated, as is the case in the example shown. The openings 70 make it possible to reduce the mass of the axial extension 54 and therefore of the distributor 50. They also allow the rotating air to pass through (the air pulsed onto the flange will be driven by the rotation of the rotor and non-aerodynamic elements such as the screws). It is indeed preferable to let this rotating air circulate so as not to create heating.

[0079] As seen in the drawings, at least some of the outlets 66, and preferably all of the outlets 66, are located at radial distances H1, H2, H3 different from the axis X. Advantageously, the radial distances H1-H3 increase as one moves away from the collector 52, that is to say that the distance H1 for the most upstream air outlet 66 is less than the distance for the intermediate air outlet 66 which is itself less than the distance for the most downstream air outlet 66. Thus, H1 < H2 < H3.

[0080] We see in figures 1 and 2 that:

[0081] - H1 < D1 / 2; H2 < D172; H3 < D1 2;

[0082] - H1 > D2 / 2; H2 < D3 / 2; H3 < D4 / 2;

[0083] - H1 can be less than or equal to D3 / 2;

[0084] - H2 can be less than or equal to D4; - H3 can be greater than D5.

[0085] These dimensions are particularly advantageous for optimizing ventilation without impacting the assembly of the rotor of the turbine 10, i.e. the fixing and clamping of the rotor wheels 12, as will be described below.

[0086] Each of the air outlets 66 may have a circular shape or an elongated shape along a circumference centered on the X axis. The elongated shape may be obtained by pinching this outlet 66 or the end of the duct 64 comprising the outlet 66, and may allow better distribution of the air at the outlet of the duct 64.

[0087] It is also noted in the drawings that the outlets 68 are respectively located in (or crossed by) the aforementioned planes U1 to U3, respectively. This means that the outlets 68 are oriented so that the air leaving the ducts 64 is projected onto the flanges 32, 34.

[0088] In the case where the distributor 50 comprises two or more axial extensions 54, these extensions would be distributed, regularly or not, around the axis X.

[0089] Figure 5 shows an alternative embodiment of the distributor 50 in which one or more of its air outlets 66 is equipped with one or more air projection nozzles 72. In the example shown, one of the outlets 68 is equipped with an element 74 comprising three air projection nozzles 72 in different directions. The element 74 is directly fitted by male-female fitting into the outlet 66 of the conduit 64. In another embodiment, the connection could be threaded.

[0090] In operation, air is collected by the distributor 50 at the collector 52 and is conveyed through the conduits 64 to their outlets 68. The air can be compressed in the sections 64a and expanded in the sections 64b. The air is then expelled at the flanges 32, 34 and is rotated by the screws or bolts fixing these flanges. This thus creates a cooling zone between 10° and 20° angular rather than a point cooling. This propagation makes the cooling more efficient. The distributor 50 is fixed and the flanges 32, 34 with the rotor of the turbine 10 are movable. The air is rotated around the X axis and ventilates the aforementioned air pockets 41 of the turbine 10, thus preventing an excessive increase in temperature in this zone.

[0091] When assembling the rotor of the turbine 10, the following steps can be carried out successively:

[0092] - the most downstream rotor wheel 14 or the disc 28 of the most downstream wheel 14 is positioned flat so that its X axis is oriented vertically,

[0093] - the distributor 50 is prepositioned axially above this wheel 14 or this disc, in its desired final position, and held in place by a frame for example,

[0094] - the other rotor wheels 14 or the other discs 28 are stacked and fixed at their flanges 32, 34, which is permitted thanks to the aforementioned dimensions.

[0095] During the step of clamping the discs 28, the distributor 50 can be moved in rotation around the X axis so as not to hinder the passage and handling of the tool to carry out this clamping, then is repositioned in its desired final position.

Claims

CLAIMS 1. Distributor (50) of ventilation air for a turbine (10) of an aircraft turbomachine, this distributor (50) comprising: - an annular air collector (52) extending around an axis (X), and - at least one axial extension (54) extending from the collector (52) along said axis (X), this axial extension (54) comprising at least two conduits (64) fluidically connected to the collector (52) and each comprising an air outlet (66) which is oriented radially outwards, the air outlets (66) of the conduits (64) being axially spaced from one another or from one another as well as from the collector (52).

2. Distributor (50) according to claim 1, wherein each of the conduits (64) comprises first and second sections (64a, 64b), the first section (64a) of each conduit (64) extending along the axis (X) from the manifold (52) to the second section (64b) which is bent.

3. Distributor (50) according to claim 2, in which the conduits (64) share the same first section (64a) and have second sections (64b) independent of each other.

4. Distributor (50) according to one of the preceding claims, in which the conduits (64) are connected to one another or to one another, or even also to said collector (62), by at least one web of material (68) which extends in a plane (P1) passing through said axis (X).

5. Dispenser (50) according to claim 4, wherein said at least one web of material (68) is perforated.

6. Distributor (50) according to one of the preceding claims, in which the collector (62) has a general C-shaped axial section and comprises an annular opening (56) which is oriented axially on the side opposite said at least one axial extension (54).

7. Distributor (50) according to one of the preceding claims, in which the collector (52) comprises an internal annular fixing flange (58) and / or an external annular fixing flange (60).

8. Distributor (50) according to one of the preceding claims, in which at least some of the air outlets (66) are located at radial distances (H1, H2, H3) different from said axis (X), and in particular at radial distances (H1, H2, H3) which increase as one moves away from said collector (52).

9. Dispenser (50) according to one of the preceding claims, wherein each of the air outlets (66) has a circular shape or an elongated shape along a circumference centered on the axis (X).

10. Dispenser (50) according to one of the preceding claims, wherein at least one of said air outlets (66) is equipped with one or more air projection nozzles (72).

11. Distributor (50) according to one of the preceding claims, wherein said at least one axial extension (54) is fluidically connected to said manifold (52) by an orifice (62) passing axially through and formed in the manifold (52).

12. Dispenser (50) according to one of the preceding claims, in which it comprises two or more axial extensions (54) distributed around said axis (X).

13. Turbine (10) for an aircraft turbomachine, comprising several expansion stages which extend around and along the same axis (X), and which each comprise a rotor wheel (12) and a stator blade (14), the rotor wheels (12) each comprising an annular disc (28) carrying blades (30) at its periphery, the disc (28) of each of the rotor wheels (12) comprising an annular flange (32) which is fixed to an annular flange (34) of the disc (28) of an adjacent rotor wheel (12), the flanges (32, 34) of the discs (28) of two adjacent rotor wheels (12) being located between the discs (28) of these wheels (12) and comprising a minimum internal diameter (D1, DT, D1”) which is greater than the minimum internal diameters (D2, D3, D4, D5) of these discs (28), the turbine (10) further comprising a distributor (50) according to one of the preceding claims which is fixed to a stator (42) of the turbine (10), this distributor (50) having its axis which is merged with the axis (X) of the turbine (10) and having its collector (52) which is located upstream of the expansion stages with reference to the flow of air in the distributor (50) from the collector (52) to the ducts (64), the air outlets (66) of the distributor (50) being located in connecting planes (U1, U2, U3) of said flanges (32, 34) which are perpendicular to said axis (X).

14. Turbine (10) according to claim 13, wherein the number of ducts (64) and air outlets (66) is n, and the number of stages or rotor wheels (12) of the turbine (10) is n+1.

15. Turbine (10) according to claim 13 or 14, wherein the air outlets (66) are located at radial distances (H1, H2, H3) from said axis (X) which increase as one moves away from said collector (52), and the discs (28) of the rotor wheels (12) have internal radii (D2 / 2, D3 / 2, D4 / 2) which increase as one moves away from said collector (52) and which are respectively less than the aforementioned distances (H1, H2, H3) of the air outlets (66) arranged directly downstream of these wheels (12) with reference to the flow of air in the distributor (50) from the collector (52) to the ducts (64).

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