Nozzle for a turbine engine comprising an inner ring provided with a collar in which orifices are formed

Abstract

This nozzle (36, 36a) for a turbine comprises an inner ring (40) and a bladed ring (42) provided with a plurality of blades (46), with an inner platform (48) and with a flange (50) extending radially inwards from the inner platform (48), the inner ring (40) being provided with a platform (52), with an upstream flange (56) and with a downstream flange (58), the upstream and downstream flanges (56, 58) extending radially outwards from the platform (52) of the inner ring (40) while being attached to the flange (50) of the bladed ring (42), the inner ring (40) comprising at least one collar (62) extending at least radially outwards from the platform (52) of the inner ring (40) while remaining at a distance from the upstream and downstream flanges (56, 58), a plurality of orifices (64) being formed in the collar (62).

Description

[0001] DESCRIPTION

[0002] Title of the invention: Distributor for turbomachinery comprising an inner ring provided with a collar in which orifices are formed

[0003] technical field

[0004] The invention has as its technical field turbomachinery, and relates in particular to the cooling of a flange of an inner ring of a distributor of a turbine of the turbomachine.

[0005] In particular, the invention relates to a distributor for a turbomachine, a turbine comprising such a distributor, a turbomachine comprising such a turbine, and an aircraft comprising such a turbomachine.

[0006] Previous techniques

[0007] A turbomachine turbine, for example as described by FR 3 117 147, comprises an alternation of moving wheels and distributors.

[0008] With reference to Figure 1, each distributor comprises an outer ring (not shown), an inner ring 2, and a bladed crown 4 fixed to the outer and inner rings 2.

[0009] The inner ring 2 of the distributor considered includes a platform 6, an upstream spoiler 8 extending axially towards a movable wheel 10 located directly upstream of the distributor considered, and a downstream spoiler 12 extending axially towards a movable wheel located directly downstream of the distributor considered.

[0010] The movable wheel 10 which is located directly upstream of the distributor in question includes a downstream spoiler 14 extending axially towards the distributor in question, being located radially outside the upstream spoiler 8 of the distributor in question.

[0011] The bladed ring 4 of the distributor under consideration includes an inner platform 16 which is located radially outside the downstream spoiler 14 of the moving wheel 10, which is located directly upstream of the distributor under consideration. This configuration is thermo-mechanically unfavorable. Indeed, the centrifugal force of the air generates pressure gradients leading to a lower pressure radially inwards than radially outwards, which in turn generates a temperature gradient between hot zones, located radially outwards, and cold zones, located radially inwards.

[0012] In particular, this configuration does not allow optimization of air circulation between a cavity formed radially inside the upstream spoiler 8 of the distributor considered and an area located radially inside the inner platform 16 of the corresponding bladed ring 4.

[0013] Description of the invention

[0014] The present invention therefore aims to overcome all or part of the aforementioned drawbacks.

[0015] The present invention relates to a distributor for a turbomachine turbine, the distributor comprising an outer ring, an inner ring, and a bladed ring mounted radially between the outer and inner rings, the bladed ring being provided with a plurality of blades, an inner platform and a flange extending radially inwards from the inner platform, the inner ring being provided with a platform, an upstream flange and a downstream flange, the upstream and downstream flanges extending radially outwards from the platform of the inner ring by being fixed to the flange of the bladed ring, the inner ring further comprising at least one collar extending at least radially outwards from the platform of the inner ring while remaining at a distance from the upstream and downstream flanges.

[0016] According to a general characteristic, a plurality of orifices are formed in said collar.

[0017] The collar defines a cavity located axially between the collar and the upstream and downstream flanges. The air pressure within the cavity formed by the collar is greater than the air pressure present axially on the opposite side of the cavity relative to the collar.

[0018] This pressure gradient allows air to circulate through the orifices formed in the flange. This generates an airflow from a cold zone, directed towards a hot zone near a radially external end of the relevant upstream or downstream flange. This airflow bypasses the flange, cools the relevant upstream or downstream flange by mixing with hot air from a turbomachine duct, and then passes through the orifices in the flange.

[0019] The terms "upstream" and "downstream" are defined according to the general direction of fluid flow within the turbomachine.

[0020] The axial, radial, and tangential directions form an orthogonal frame of reference, with the axial direction being parallel to an axis of rotation of the moving wheels of the turbomachine.

[0021] Advantageously, each orifice formed in said collar is oblong in shape and extends circumferentially.

[0022] This particular shape of openings improves air circulation through the collar.

[0023] Optionally, the radial dimension of each orifice is constant over more than 80% of the dimension of the orifice considered in the circumferential direction.

[0024] Advantageously, the flange of the bladed crown is fixed to the upstream and downstream flanges by a plurality of screw / nut systems, said flange comprising a plurality of recesses formed opposite the screw / nut pairs.

[0025] Thus, the collar does not interfere with the attachment of the flange of the bladed crown to the upstream and downstream flanges.

[0026] According to an initial design, the said collar extends purely radially.

[0027] According to a second alternative design, said collar extends radially and axially opposite the upstream and downstream flanges.

[0028] According to a first variant, said collar extends from an upstream end of the inner ring platform. According to a second alternative variant, said collar extends from a downstream end of the inner ring platform.

[0029] The present invention also relates to a turbine for a turbomachine comprising at least one distributor as defined above, and at least one moving wheel adjacent to said distributor.

[0030] Optionally, said wheel includes a spoiler extending at least axially towards said distributor, the diameter of a large diameter edge of said collar of said distributor being less than the diameter of a small diameter edge of the spoiler of said wheel.

[0031] Preferably, the turbine is a low-pressure turbine for a turbomachine.

[0032] The present invention also relates to an aircraft turbomachine comprising at least one turbine as defined above.

[0033] The present invention also relates to an aircraft comprising at least one turbomachine as defined above.

[0034] Brief description of the drawings

[0035] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example and made with reference to the accompanying drawings in which:

[0036] [Fig 1] illustrates a radially internal part of a distributor according to the prior art;

[0037] [Fig 2] illustrates an aircraft according to an example of an embodiment of the invention;

[0038] [Fig 3] is a cross-sectional view of a turbomachine from the aircraft in Figure 2;

[0039] [Fig 4] is a cross-sectional view of a low-pressure turbine from the turbomachine in Figure 3;

[0040] [Fig 5] is a cross-sectional view of a radially internal portion of a distributor of the turbine in Figure 4; and [Fig 6] is a perspective view of a radially internal portion of the distributor in Figure 5.

[0041] Detailed description

[0042] Figure 2 schematically represents an aircraft 18 comprising a plurality of turbomachines 20.

[0043] With reference to Figure 3, each turbomachine 20 comprises, axially from upstream to downstream, a blower 22, a low-pressure compressor 24, a high-pressure compressor 26, a combustion chamber 28, a high-pressure turbine 30, and a low-pressure turbine 32. The axial direction Z, radial direction R, and tangential direction T form an orthogonal frame of reference.

[0044] As illustrated in figures 4 to 6, the low pressure turbine 32 comprises an alternation along the axial direction of moving wheels 34 and distributors 36, and here comprises four moving wheels 34a, 34b, 34c, 34d and three distributors 36, namely an upstream distributor 36a, a central distributor 36b and a downstream distributor 36c.

[0045] Each wheel 34 comprises a plurality of movable blades rotating about a longitudinal axis of the turbomachine 20. Each wheel 34 comprises an upstream blade extending axially upstream from an inner platform of the wheel 34 under consideration, and a downstream blade 38 extending axially downstream from the inner platform of the wheel 34 under consideration.

[0046] Each distributor 36 comprises an outer ring, an inner ring 40, a bladed crown 42 mounted radially between the outer and inner rings 40, and a plurality of screw / nut systems 44.

[0047] The bladed ring 42 comprises a plurality of fixed blades 46 circumferentially arranged around the longitudinal axis, an inner platform 48, and an outer platform. The inner 48 and outer platforms of the bladed ring 42 define a primary flow channel of the turbomachine 20. The bladed ring 42 is annular and is, for example, sectored. The bladed ring 42 further comprises a flange 50 extending radially inward from the inner platform 48.

[0048] The inner ring 40 includes a platform 52, an abradable material 54, an upstream flange 56 and a downstream flange 58. The inner ring 40 is annular and is, for example, sectorized.

[0049] The abradable material 54 extends radially inwards from a radially inner face of the platform 52 of the inner ring 40. The abradable material 54 forms a dynamic seal with the lugs 60 of a ferrule which is connected to the movable wheels 34.

[0050] The upstream and downstream flanges 56, 58 are axially spaced from each other and extend radially outwards from a radially outward face of the platform 52 of the inner ring 40, and substantially parallel to each other.

[0051] The upstream and downstream flanges 56, 58 of the platform 52 of the inner ring 40 and the flange 50 of the bladed ring 42 are each provided with holes inside which the screw / nut pairs 44 are arranged so as to secure the inner ring 40 and the bladed ring 42.

[0052] Each distributor 36 includes at least one collar 62 extending at least radially outwards from the platform 52 of the inner ring 40 while remaining at a distance from the upstream and downstream flanges 56, 58. A plurality of orifices 64 are formed in each of the collars 62.

[0053] As illustrated more visibly in Figures 5 and 6, the upstream distributor 36a includes a collar 62 which extends purely radially outwards from the upstream end of the platform 52 of the inner ring 40 of the upstream distributor 36a.

[0054] The flange 62 of the upstream distributor 36a extends towards the downstream spur 38 of the moving wheel 34a, which is located directly upstream of the upstream distributor 36a. The diameter of the large-diameter edge of the flange 62 of the upstream distributor 36a is strictly smaller than the diameter of the small-diameter edge of the downstream spur 38 of the moving wheel 34a, which is located directly upstream of the upstream distributor 36a.

[0055] The orifices 64 formed in the flange 62 of the upstream distributor 36a are oblong in shape and each extends circumferentially over a limited circumferential sector. These orifices 64 have a substantially constant radial dimension, that is to say, a constant radial dimension over more than 80% of the circumferential dimension of the orifice 64 under consideration.

[0056] The flange 62 of the upstream distributor 36a is perforated. In particular, the flange 62 comprises a plurality of recesses 66, each formed opposite one of the screw / nut pairs 44.

[0057] The upstream distributor 36a further includes a downstream spoiler extending axially downstream from the downstream flange 58. The diameter of the large-diameter edge of the downstream spoiler of the upstream distributor 36a is strictly smaller than the diameter of the small-diameter edge of the upstream spoiler of the rotating wheel 34b, which is located directly downstream of the upstream distributor 36a.

[0058] An arrow in Figure 5 represents an airflow path generated by the presence of the flange 62 of the upstream distributor 36a. The symbols "+" and "-" schematically represent the distribution of air pressure around the flange 62 of the upstream distributor 36a, the pressure "++" being greater than the pressure "+" which is greater than the pressure "-" which is greater than the pressure "-".

[0059] With reference to Figure 4, the inner ring 40 of the central distributor 36b comprises an upstream flange 62 extending radially outwards and axially upstream from the upstream end of the platform 52 of the inner ring 40 of the central distributor 36b, and a downstream flange 62 extending radially outwards and axially upstream from the downstream end of the platform 52 of the inner ring 40 of the central distributor 36b. The inner ring 40 of the downstream distributor 36c comprises an upstream flange 62 extending radially outwards and axially upstream from the upstream end of the platform 52 of the inner ring 40 of the downstream distributor 36c. The flanges 62 of the central and downstream distributors 36b, 36c may include recesses 66 opposite the screw / nut pairs 44.The orifices 64 of the collars 62 of the central and downstream distributors 36b, 36c can be identical to the orifices 64 of the collar 62 of the upstream distributor 36a.

[0060] In the example shown, each distributor 36 includes a collar 62 extending from the upstream end of the platform 52 of the inner ring 40 concerned. Alternatively, a distributor 36 could include a collar 62 extending from the downstream end of the platform 52 of the inner ring 40 concerned, while lacking a collar 62 extending from the upstream end of the platform 52 of the inner ring 40 concerned.

Claims

DEMANDS 1. Distributor (36, 36a, 36b, 36c) for a turbine (30, 32) of a turbomachine (20), the distributor (36, 36a, 36b, 36c) comprising an outer ring, an inner ring (40), and a bladed ring (42) mounted radially between the outer and inner rings (40), the bladed ring (42) being provided with a plurality of blades (46), an inner platform (48), and a flange (50) extending radially inward from the inner platform (48), the inner ring (40) being provided with a platform (52), an upstream flange (56), and a downstream flange (58), the upstream and downstream flanges (56, 58) extending radially outward from the platform (52) of the inner ring (40) by being fixed to the flange (50) of the winged crown (42), the inner ring (40) further comprising at least one collar (62) extending at least radially outwards from the platform (52) of the inner ring (40) while remaining at a distance from the upstream and downstream flanges (56, 58),characterized in that a plurality of orifices (64) are formed in said collar (62), the flange (50) of the bladed crown (42) being fixed to the upstream and downstream flanges (56, 58) by a plurality of screw / nut systems (44), said collar (62) comprising a plurality of recesses (66) formed opposite the screw / nut pairs (44).

2. Distributor (36, 36a, 36b, 36c) according to claim 1, wherein each orifice (64) formed in said collar (62) is oblong in shape and extends circumferentially.

3. Distributor (36, 36a, 36b, 36c) according to claim 1 or 2, in which said collar (62) extends purely radially.

4. Distributor (36, 36a, 36b, 36c) according to claim 1 or 2, wherein said collar (62) extends radially and axially opposite the upstream and downstream flanges (56, 58).

5. Distributor (36, 36a, 36b, 36c) according to any one of claims 1 to 4, wherein said collar (62) extends from an upstream end of the platform (52) of the inner ring (40).

6. Distributor (36, 36a, 36b, 36c) according to any one of claims 1 to 4, wherein said collar (62) extends from a downstream end of the platform (52) of the inner ring (40).

7. Turbine (30, 32) for turbomachine (20) comprising at least one distributor (36, 36a, 36b, 36c) according to any one of claims 1 to 6, and at least one wheel (34, 34a, 34b, 34c, 34d) adjacent to said distributor (36, 36a, 36b, 36c).

8. Turbine (30, 32) according to claim 7, wherein said wheel (34, 34a, 34b, 34c, 34d) comprises a spoiler (38) extending at least axially towards said distributor (36, 36a, 36b, 36c), the diameter of a large diameter edge of said collar (62) of said distributor (36, 36a, 36b, 36c) being less than the diameter of a small diameter edge of the spoiler of said wheel (34, 34a, 34b, 34c, 34d).

9. Turbine (30, 32) according to claim 7 or 8, constituting a low pressure turbine (32) for turbomachine (20).

10. Turbomachine (20) for aircraft (18) comprising at least one turbine (30, 32) according to any one of claims 7 to 9.

11. Aircraft (18) comprising at least one turbomachine (20) according to claim 10.

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