Sealing strip for turbomachine turbine

Abstract

Sealing flap for turbomachine turbine. This document relates to a sealing flap (30a, 30b, 30c, 30d) for a turbomachine turbine, in particular for a turbine wheel, extending in a first direction (L1) and a second direction (L2) substantially perpendicular to each other, comprising a first part (32) and a second part (34) connected to each other by an intermediate portion (36a, 36b, 36c, 36d) in the first direction, wherein the first part (32) and the second part (34) are substantially planar in the first direction (L1) and the second direction (L2), and wherein the intermediate portion (36a, 36b, 36c, 36d) is shaped to have less rigidity than the first part (32) and the second part (34) in a third direction (L3) perpendicular to the first direction. (L1) and the second direction (L2). Abbreviated figure: Figure 5

Description

Title of the invention: Sealing strip for turbomachine turbine technical field

[0001] This document relates to the field of sealing fins for turbine ring sectors and to a ring comprising such fins. Prior art

[0002] Figure 1 represents a twin-spool, twin-flow turbomachine 1. The axis of the turbomachine is referenced as X and corresponds to the axis of rotation of the rotating parts. In what follows, the terms axial and radial are defined with respect to the X axis.

[0003] The turbomachine 1 comprises, from upstream to downstream in the direction of gas flow, a blower 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.

[0004] The air from the blower 2 is divided into a primary flow 8 flowing into a primary annular vein 9, and a secondary flow 10 flowing into a secondary annular vein 11 surrounding the primary annular vein 10.

[0005] The low pressure compressor 3, the high pressure compressor 4, the combustion chamber 5, the high pressure turbine 6 and the low pressure turbine 7 are provided in the primary vein 9.

[0006] The rotor of the high-pressure turbine 6 and the rotor of the high-pressure compressor 4 are coupled in rotation via a first shaft 12 so as to form a high-pressure body.

[0007] The rotor of the low-pressure turbine 7 and the rotor of the low-pressure compressor 3 are coupled in rotation via a second shaft 13 so as to form a low-pressure body, the blower 2 being able to be connected directly to the rotor of the low-pressure compressor 3 or via an epicyclic gear train for example.

[0008] As can be seen more clearly in [Fig. 2], the low-pressure turbine 7 comprises, in particular, several successive stages including rotating wheels 14 and stationary parts. The rotating wheel has a disc 15 on which blades 16 are mounted. The ends of the blades 16 are surrounded by a fixed ring 17 made of abradable material, said ring 17 being fixed to the turbine housing 18. Distributors 19 are located downstream of the rotating wheels 14. The distributors 19 and the rings 17 are mounted on the housing by means of flanges or hooks 20 extending from the radially internal surface of the housing 18.

[0009] Each ring 17 is sectorized, that is, it is composed of several angular sectors 21 arranged contiguously. A sector 21 of ring 17 is shown in [Fig. 3]. Each sector 21 has a radially external part 22 and a radially internal part formed by a block of abradable material 23 fixed, for example by brazing, to the radially internal surface 24 of the external part 22. The circumferential ends of the support have slots 25 in which sealing strips 26 are mounted extending between the sectors 21, as illustrated in [Fig. 4].

[0010] The use of sectors makes it possible to compensate for the effects of thermal expansion during operation and the fins make it possible to avoid or limit leaks of hot gas outside the primary stream.

[0011] Mounting the slats 26 between the sectors is relatively tedious, due in particular to the small size of the slats 26 and the slots 25. Indeed, a radial offset between two circumferentially facing slots can make mounting the slat difficult, or even impossible (Figure 4B). In such a configuration, it may then be necessary to disassemble one of the sectors and replace it with a sector having a slot positioned in a way suitable for mounting a slat. Furthermore, as illustrated in Figure 4A, the slats can have complex shapes formed of several parts allowing insertion into several slots 25 of the circumferential edges of the sectors 21, which further stiffens the slats 26 and further complicates their mounting. Summary

[0012] This document relates to a sealing flap for a turbomachine turbine, in particular for a turbine wheel, extending along a first direction and a second direction substantially perpendicular to each other, comprising a first part and a second part connected to each other by an intermediate part along the first direction, in which the first part and the second part are substantially planar along the first and second directions and in which the intermediate part is shaped so as to exhibit a lower rigidity than the first and second parts along a third direction perpendicular to the first and second directions.

[0013] According to the invention, varying the rigidity of the intermediate part and lowering its rigidity relative to the first and second parts makes it possible to create an intermediate part that allows the first part to be angled relative to the second part. This intermediate part acts as a pivot whose axis lies in the plane formed by the first and second directions.

[0014] According to another feature, the intermediate part comprises at least two segments extending along the third direction, a first segment of said two segments extending along a first direction of the third direction and a second segment extending along a second direction of the third direction, the first direction being opposite to the second direction.

[0015] According to the present document, the lamella thus comprises an intermediate part which is a median portion because it is intercalated along the first direction and the second direction along the first direction, this second part comprising two segments whose conformation along the third direction makes it possible to facilitate the angular deformation of the first portion relative to the third part by means of the intermediate part.

[0016] The first segment and the second segment can be directly connected to each other.

[0017] According to this configuration, the first segment and the second segment can each have a common end connecting the two segments together and an opposite end connected respectively to the first part and the second part.

[0018] The first segment and the second segment can be connected to each other by a third segment.

[0019] The intermediate part may comprise N segments arranged successively one after the other so as to form one or more successive undulations.

[0020] In a particular embodiment of the invention, the undulations are linearly shaped.

[0021] The lamella may have a generatrix along the first direction and a director along a direction extending at least along the second direction.

[0022] The director can extend along the second direction.

[0023] The lamella may have a plane of symmetry extending along the second and third directions.

[0024] The lamella may have a central axis of symmetry along an axis extending along the second and third directions.

[0025] The lamella can have a substantially constant thickness from one end of the lamella to the other along the first direction.

[0026] The intermediate part may comprise two pairs of segments symmetrical to each other with respect to a plane comprising the first direction and the third direction, said two pairs of segments being connected to each other by a segment in C.

[0027] This shape allows for good flexibility of the intermediate part while having a reduced bulk along the first direction.

[0028] The segment in C may have a concavity oriented along the third direction.

[0029] This document also relates to a sectored ring, in particular a turbine ring, comprising a plurality of sectors arranged circumferentially end to end and each having a slot at each circumferential end, a lamella such that described previously being mounted in a slot of a sector and in a circumferentially opposite slot of a circumferentially adjacent sector. Brief description of the drawings

[0030] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analysis of the accompanying drawings, on which:

[0031] [Fig-1] is an axial cross-sectional view of a state-of-the-art turbofan engine prior,

[0032] [Fig.2] is an axial cross-sectional view of a portion of the prior art turbojet engine, illustrating in particular the low-pressure turbine,

[0033] [Fig.3] is a detailed perspective view illustrating part of a prior art sectorized turbine ring,

[0034] [Fig.4] is a schematic view illustrating the problem of assembling a complex lamella in a plurality of circumferential sector slots,

[0035] [Fig.5] comprises several parts each illustrating an embodiment of a lamella according to the invention and according to a cutting plane comprising a first direction and a third direction perpendicular to each other. Detailed description of the invention

[0036] Reference is now made to [Fig. 5], which shows several embodiments of the invention of a lamella 30a, 30b, 30c, 30d. In each embodiment, the lamella 30a, 30b, 30c, 30d extends along a first direction L1 and a second direction L2, substantially perpendicular to each other. In [Fig. 5], the second direction L2 corresponds to a direction perpendicular to the plane of the figure. A third direction L3 is formed by the direction perpendicular to the first and second directions L1, L2.The lamella 30a, 30b, 30c, 30d comprises a first part 32 and a second part 34 connected to each other by an intermediate portion 36a, 36b, 36c, 36d along the first direction L1, in which the first part 32 and the second part 34 are substantially planar along the first direction L1 and the second direction L2, and in which the intermediate portion 36a, 36b, 36c, 36d is shaped so as to exhibit a lower rigidity than the first part 32 and the second part 34 along a third direction L3 perpendicular to the first direction L1 and the second direction L2. It is observed that the first part 32 and the second part 34 extend in the same plane comprising the first direction L1 and the second direction L2.

[0037] In a first embodiment shown in Figure 5A, the intermediate part 36a comprises at least two segments 38, 40 extending along the third direction L3, a first segment 38 of said two segments extending along a first direction L3-1 of the third direction L3 and a second segment 40 extending along a second direction L3-2 of the third direction L3, the first direction L3-1 being opposite to the second direction L3-2. The first part 32 is therefore connected to a first segment 38 which is connected to the second segment 40, the latter being connected to the second part 34.

[0038] According to a more general formulation, the intermediate portion 36a, 36b, 36c, 36d may comprise N segments arranged successively one after the other in a given direction of the first direction L1 so as to form one or more successive undulations. The number of segments may be even or odd. It is understood that the 2k+l segments extend in a first direction L3-1 of the third direction L3 and that the 2k segments extend in a second direction L3-2 of the third direction L3. The ends of the segments are connected to each other by rounded portions 42 in order to facilitate the deformation of the intermediate portion. The radius of curvature of said rounded portions 42 may be less than 0.2 mm, preferably less than 0.1 mm. There could be an even number of segments (figures 5A and 5B) or an odd number of segments (figures 5C and 5D).

[0039] The term "segment" should be interpreted as a portion of the junction between two elements and is not necessarily rectilinear in section along a plane comprising the first direction L1 and the third direction L3.

[0040] As shown in Figure 5B, the intermediate part 36b may exhibit symmetry about a plane comprising the second direction L2 and the third direction L3. It has an even number of segments, in particular four segments 44. In the case of Figure 5C, the lamella 30b has an axis of central symmetry about an axis extending along the second direction L2 and the third direction L3. It has an odd number of segments.

[0041] Although not shown in the figures, the lamella 30a, 30b, 30c, 30d could have a generatrix along the first direction and a director along a direction extending at least along the second direction. This director could be oriented strictly along the second direction L2 or extend partially along the second direction. The generatrix is ​​formed by the cutting line of the lamella 30a, 30b, 30c, 30d illustrated in [Fig. 5].

[0042] In the embodiment of Figure 5A, the lamella 30a comprises only two segments 38, 40 of the same length and which are symmetrical to each other along a plane comprising the second direction L2 and the third direction L3. The two segments 38, 40 could still have different lengths.

[0043] The lamella 30a, 30b, 30c, 30d can have a substantially constant thickness from one end to the other along the first direction LL. The lamella 30a, 30b, 30c, 30d can be formed by successive deformation operations of an initially completely flat lamella.

[0044] In the embodiments of figures 5A, 5B and 5C, the lamella 30a, 30b, 30c could extend relative to the first part 32 and the second part 34 over a distance along the third direction L3 which could be identical or different.

[0045] Figure 5D illustrates an intermediate portion 30d comprising two pairs of segments symmetrical to each other with respect to a plane comprising the first direction L1 and the third direction L3, said two pairs of segments being connected to each other by a portion C. The first pair of segments comprises a first segment 46 oriented along the first direction of the third direction L3 from the first portion 32 and a second segment 48 oriented along the second direction of the third direction from the first segment. The first segment 46 is shorter than the second segment 48. The second segment 48 comprises two successive portions, a first portion 48a substantially parallel to the first segment 46 and a second portion 48b crossing the plane formed by the first direction L1 and the second direction L3.The second pair of segments 52, 54 is identical to the first pair of segments and is symmetric to the first pair of segments with respect to a plane comprising the second direction L2 and the third direction L3. The ends of the second segments 48 of each pair of segments are connected by a segment 50 having a C shape whose concave portion is oriented along the second direction L3-2 of the third direction L3. The junctions of the segment 50 to the said ends of the second segments 48, 54 are made by rounded portions 42.

[0046] It is observed that the first segment 46 of the first pair of segments and the first segment 52 of the second pair of segments extend along the first direction L3-1 of the third direction L3 and extend towards each other along the first direction LL. Together they define a circular arc with a radius of curvature RC1. The C-shaped segment 50 may have a constant radius of curvature RC2. This radius of curvature RC2 may be between 40 and 60% of the radius of curvature RC1 and preferably about 50% of the radius of curvature RC1. The circle Cl defined by the first segments 46 and 52 is concentric with the circle defined by the C-shaped segment 50.

[0047] The intermediate part 36a, 36b, 36c, 36d could have a dimension along the third direction L3 between 1 and 4 mm and a dimension along the first direction L1 between 1 and 3 mm.

[0048] With regard to figure 5A, the height of the intermediate part can be substantially also to its width.

[0049] With regard to figures 5B and 5C, the intermediate part can extend along the third direction L3 over a distance between 2 and 3 times the distance over which a complete undulation extends along the first direction LL. An undulation is formed by the equivalent of one wavelength.

[0050] With regard to figure 5D, the height of the intermediate part can be substantially also to its width.

Claims

Demands

1. A sealing blade (30a, 30b, 30c, 30d) for a turbomachine turbine, in particular for a turbine wheel, extending along a first direction (L1) and a second direction (L2) substantially perpendicular to each other, comprising a first portion (32) and a second portion (34) connected to each other by an intermediate portion (36a, 36b, 36c, 36d) along the first direction, wherein the first portion (32) and the second portion (34) are substantially planar along the first direction (L1) and the second direction (L2), and wherein the intermediate portion (36a, 36b, 36c, 36d) is shaped to have less rigidity than the first portion (32) and the second portion (34) along a third direction (L3) perpendicular to the first direction (L1) and the second direction (L2). (L2).

2. Sealing strip according to claim 1, wherein the intermediate part (36a, 36b, 36c, 36d) comprises at least two segments (38, 40, 44) extending along the third direction (L3), a first segment (38, 44) of said two segments extending along a first direction of the third direction (L3) and a second segment extending along a second direction of the third direction (L3), the first direction being opposite to the second direction.

3. Lamella according to claim 1 or 2, wherein the first segment (38) and the second segment (40) are directly connected to each other.

4. Lamella according to claim 1 to 3, wherein the intermediate part (36a, 36b, 36c, 36d) comprises N segments arranged successively one after another so as to form one or more successive undulations.

5. Lamella according to any one of the preceding claims, wherein the lamella (36a, 36b, 36c, 36d) has a generatrix along the first direction and a director along a direction extending at least along the second direction.

6. Lamella according to the preceding claim, in which the director extends along the second direction.

7. Lamella according to any one of the preceding claims, wherein the lamella (30a, 30b, 30d) has a plane of symmetry extending along the second direction (L2) and the third direction (L3).

8. Lamella according to any one of claims 1 to 6, wherein the lamella (36c) has a central axis of symmetry along an axis extending along the second direction (L2) and the third direction (L3).

9. Lamella according to any one of the preceding claims, wherein it has a substantially constant thickness from one end to the other of the lamella along the first direction (Ll).

10. Lamella according to any one of the preceding claims, wherein the intermediate part (36d) comprises two pairs of segments symmetric to each other with respect to a plane comprising the first direction (L1) and the third direction (L3), said two pairs of segments being connected to each other by a segment (50) at C.

11. Lamella according to claim 10, wherein the segment in C has a concavity oriented along the third direction.

12. Sectorized ring, in particular turbine, comprising a plurality of sectors arranged circumferentially end to end and each comprising a slot at each circumferential end, a blade according to one of the preceding claims being mounted in a slot of a sector and in a circumferentially opposite slot of a circumferentially adjacent sector.

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