EP4291757A1

EP4291757A1 - Guide vanes assembly with position-maintaining device

Info

Publication number: EP4291757A1
Application number: EP22708195.7A
Authority: EP
Inventors: Sébastien Serge Francis CONGRATEL; Aurélien Gaillard; Matthieu Arnaud GIMAT; Clément Jarrossay; David René Pierre LE CAIR
Original assignee: Safran Aircraft Engines SAS; Safran Ceramics SA
Current assignee: Safran Aircraft Engines SAS; Safran Ceramics SA
Priority date: 2021-02-12
Filing date: 2022-02-08
Publication date: 2023-12-20
Also published as: FR3119861A1; FR3119861B1; CN117062966A; WO2022171955A1

Abstract

Turbomachine guide vanes assembly (10) extending about an axis (70) and comprising blading (20) mounted between an outer shroud (42) and an inner shroud (30), and a position-maintaining device (60) configured to be arranged in an elastically prestressed state between the inner shroud (30) and an inner platform (22) of the blading (20) in order to exert, on the blading (20), a stress towards the outer shroud (42) The contact between the inner shroud (30) and the inner platform (22) is produced by one and the same surface (64) of the position-maintaining device (60).

Description

Title of the invention:

DISTRIBUTOR WITH POSITION HOLDING DEVICE

Technical area

The invention relates to turbomachines, in particular aeronautical turbomachines or industrial turbines comprising a distributor whose blading is made of ceramic matrix composite.

Prior technique

[0002] A composite material with a ceramic matrix, hereinafter referred to by the expression “CMC material” or “CMC”, generally comprises a reinforcement of fibers within an at least partly ceramic matrix.

[0003] Increasingly high operating temperatures are implemented within turbomachines in order to improve their performance and reduce their polluting emissions.

[0004] To this end, the choice of materials for the hottest parts of the turbomachines fell on the CMCs.

[0005] CMC materials have excellent mechanical properties at high temperature, as well as low densities allowing the turbines to be lightened.

[0006] In particular, the use of CMC materials for turbine distributors has been proposed, for example in the French patent application FR 3061928.

[0007] The integration of a CMC part within a turbine nozzle is however complicated within a metallic environment, due to differences in thermal expansion.

[0008]There is therefore a need for a device that facilitates the integration and holding in position of a CMC part within a turbomachine distributor.

Disclosure of Invention

This presentation relates to a turbomachine distributor extending around an axis and comprising: a blading mounted between an outer shroud and an inner shroud, and a position-holding device configured to be disposed in an elastically prestressed state between the inner shroud and an inner platform of the blading in order to exert a constraint on the blading oriented towards the outer shell.

In the present presentation, the main axis is the main axis of the distributor, and by extension the main axis of the turbine in which the distributor is to be mounted. The axial direction corresponds to the direction of the main axis and a radial direction is a direction perpendicular to this axis and intersecting this axis. Similarly, an axial plane is a plane containing the main axis and a radial plane is a plane perpendicular to this axis. A circumference is understood as a circle belonging to a radial plane and whose center belongs to the axis of the distributor. A tangential or circumferential direction is a direction tangent to a circumference; it is perpendicular to the axis but does not pass through the axis. A circumferential plane is a plane strictly parallel to the axis, i.e. not intersecting the axis at infinity and not including the axis. An “at least” extension along an axial (respectively radial) direction is an extension at least partially along a direction which has a non-zero axial (respectively radial) component.

[0011] Unless specified otherwise, the adjectives interior, internal, exterior and external are used with reference to a radial direction so that the interior or internal part of an element is, in a radial direction, closer to the axis than the outer or outer part of the same element.

[0012] Subsequently, and unless otherwise indicated, by "a" or "G" element (for example pipe, bearing, etc.), we mean "at least one" or "the at least one" or even " each » element. Conversely, the generic use of the plural may include the singular. Thereafter, and unless otherwise indicated, by "a plurality" is meant "at least two".

[0013] “Blade” is understood to mean a set of one or more blades which may have, in the context of a turbomachine distributor, an aerodynamic function of straightening the flow of the working fluid.

[0014] In such a distributor, the position-holding device exerts a stress in reaction to its elastically prestressed state, making it possible to pressing the blading against the outer shroud while limiting the forces in the position-holding device.

[0015] Such a distributor thus makes it possible to hold the blading in position for different operating phases of the turbine and without significant change in the usual structure of a distributor.

[0016] In certain embodiments, the contact between the inner shroud and the inner platform is made by the same surface of the position-holding device.

[0017] Such a device for maintaining position has a simple structure, facilitating its dimensioning and its integration within the dispenser.

[0018] In some embodiments, the surface of the position-keeping device may extend continuously between the two ends of the position-keeping device.

It is understood that the contact does not take place at the same positions of the surface of the position-holding device, but at two different positions of the same surface.

[0020] In some embodiments, the orientation of an outer surface of the position-holding device varies by more than 180° by traversing the outer surface between the two ends. The outer surface may correspond to the surface of the position-holding device.

[0021] In certain embodiments, the position-holding device comprises at least one curved sheet, preferably two curved sheets.

The curved structure of the sheet imparts spring-like deformability properties to the position-holding device, facilitating the application of elastic pre-stress.

[0023] The use of two plates makes it possible to increase the stiffness of the device for holding in position in the direction of application of the elastic prestress. In particular, the use of two sheets makes it possible to increase the level of prestressing for the same deformation compared to a structure with a single sheet. [0024] In some embodiments, the two curved sheets have common ends.

Each sheet thus has a first and a second end, the first ends joining together, the second ends joining together.

[0026] The two curved sheets thus behave like two springs in parallel, the stiffnesses of which can be added, making it possible to facilitate dimensioning by adjusting the desired level of elastic prestress and its corresponding level of deformation by adjusting the stiffness of the hold in position.

[0027] In some embodiments, one of the two sheets is nested in the other of the two sheets.

[0028] By "nested sheets" is understood sheets having a common shape and located successively inside one another.

[0029] In certain embodiments, the prestressing is carried out for a compression corresponding to a displacement between 0.2 mm and 1 mm, preferably 0.4 mm and 0.8 mm, preferably 0.6 mm between a state of rest and the elastically prestressed state. .

The displacement corresponding to the prestress is measured between the positions corresponding to the respective contact zones of the device for maintaining position with the internal shroud and with the internal platform of the blading.

[0031] Such levels of deformation make it possible to ensure a reaction force on the blading sufficient to ensure that the blading is held in position, while presenting low risks of damage to the blading.

[0032] In certain embodiments, the prestressing is carried out by mounting the blading on the device for holding it in position between the outer shroud on the one hand and the inner shroud on the other hand.

[0033] Such a dispenser has an easier assembly operation, reducing the risk of damage. [0034] In some embodiments, the blading comprises at least one hollow vane to allow the passage of a radial mast securing the inner shroud to the outer shroud.

[0035] The mast ensures a function of structural reinforcement structure of the distributor. The at least one vane makes it possible to straighten the flow of gas from the combustion chamber.

[0036] In certain embodiments, the at least one blade can be formed over an entire circumferential contour of the distributor.

[0037] In certain embodiments, a radial mast can be formed between each profiled element.

[0038] In some embodiments, the mast may protrude from the outer shroud and be secured to the inner shroud by quibbling. Alternatively, the mast can also project from the inner shroud and be fixed to the outer shroud by ergotage.

[0039] In some embodiments, the inner shroud has a clamping projection, configured to limit the movement of the position-holding device in an axial direction of the dispenser.

[0040] The clamping projection makes it possible to ensure the correct axial positioning of the device for holding it in position. A distributor having such a device for holding in position thus has easier assembly, while allowing proper application of a stress without risk of damaging the parts.

[0041] In some embodiments, the inner shroud has a clamping projection, configured to limit movement in a circumferential direction of the dispenser.

[0042] The clamping projection makes it possible to maintain the circumferential position of the position-holding device. This makes it possible to facilitate contact between the device for maintaining position and the internal shroud, and between the device for maintaining position and the internal platform of the blading. Such a device for holding in position also has easy assembly. [0043] In certain embodiments, the distributor comprises at least two position-holding devices respectively connected circumferentially and each disposed against at least one blade.

Such a structure allows circumferential clamping of the blading. Such a structure also facilitates a uniform distribution of forces over a circumferential contour of the blading.

[0045] The plurality of position-maintaining devices thus forms a position-maintaining crown allowing easy assembly of the position-maintaining devices, by ensuring an assembly of the position-maintaining crown rather than an assembly of each position-maintaining device. hold in position successively. Such a structure also makes it easier to comply with coaxiality tolerances.

In some embodiments, the blading is made of CMC material.

This presentation also relates to a turbine engine comprising a distributor according to this presentation. In particular, the distributor can be arranged downstream of a combustion chamber.

This presentation also relates to an aircraft comprising the turbine engine according to this presentation.

Brief description of the drawings

[0049] [Fig. 1] Figure 1 is a partial schematic view of a turbine nozzle according to the invention.

[0050] [Fig. 2] Figure 2 is a schematic sectional view along an axial plane of a turbine nozzle according to the invention.

[0051] [Fig. 3] Figure 3 is a schematic cutaway perspective view along a circumferential plane of a turbine nozzle according to the invention.

[0052] [Fig. 4] Figure 4 is a schematic sectional view along a radial plane of a turbine nozzle according to the invention, according to section plane IV of Figure 1.

[0053] [Fig. 5A] FIG. 5A is a diagrammatic view of a position-holding device according to the invention. [0054] [Fig. 5B] Figure 5B is a schematic view of a transverse section of a device for maintaining in position according to the invention.

[0055] [Fig. 5C] [Fig. 5D] [Fig. 5E] [Fig. 5F] [Fig. 5G] FIGS. 5C to 5G represent schematic cross-sectional views of alternative position-holding devices.

[0056] [Fig. 6A] FIG. 6A is a schematic cutaway perspective view of a turbine nozzle comprising a ring for holding in position according to a first embodiment.

[0057] [Fig. 6B] FIG. 6B is a schematic cutaway perspective view of a turbine nozzle comprising a ring for holding in position according to a second embodiment.

Description of embodiments

Figures 1 and 2 respectively show a partial schematic view and a schematic sectional view along an axial plane of a turbine distributor 10 according to the invention. Figure 3 shows a schematic view in cutaway perspective along a circumferential plane of a turbine nozzle according to the invention. Figure 4 is a schematic sectional view along plane IV of Figure 1.

[0059] In Figures 1, 2, 3, 4, 6A and 6B, the distributor 10 is shown in a partial view, but it is understood that it extends circumferentially around a main axis 70.

The distributor 10 has an outer shroud 42 and an inner shroud 30. The outer shroud 42 is located at a position radially outside of the distributor 10, and the inner shroud 30 is located at a position radially inside from the distributor 10.

A blading 20 is mounted between the outer shroud 42 and the inner shroud 30. The blading is formed from composite material with a ceramic matrix.

The outer shroud 42 and the inner shroud 30 are connected and secured by a radial mast 44, the radial mast 44 ensures that the structure of the distributor 10 is held in position. [0063] The outer shroud 42 and the mast 44 are formed together in one piece, so as to form a mast and outer shroud assembly 40. The assembly 40 can then be assembled with the inner shroud 30 so that the mast 44 connects the inner shroud 30 and the outer shroud 42. The mast 44 can then be assembled in the blading 20, so as to mount the mast and outer shroud 40 assembly in the distributor 10.

The formation of a single piece of the assembly mast and outer shroud 40 can be achieved by an additive manufacturing method, for example by laser fusion on a powder bed.

The distributor 10 may comprise a plurality of masts 44 arranged on a circumferential contour of the distributor 10. The plurality of masts 44 is arranged regularly along a circumferential contour of the distributor 10.

The blading 20 has an outer platform 26, at a position of the blading 20 radially outside. The blading 20 has an internal platform 22, at a position of the blading 20 radially inside.

The blading 20 comprises one or more vanes 24.

The blades 24 allow the straightening of a gas flow, in particular a flow of combustion gas from a combustion chamber of the turbine. For the sake of visibility of the internal elements of the distributor 10, the vanes 24 are not shown in Figures 1 and 2, and are shown in section in Figures 3, 4, 6A and 6B.

These blades 24 extend radially between the internal platform 22 and the external shroud 42.

The blades 24 are delimited radially on the inside by the internal platform 22, and radially on the outside by an external platform 26.

[0071] A thermal cowling 23 can be positioned against a radially inner face of the internal platform 22. The thermal cowling 23 makes it possible to thermally protect the hot fluid flowing through the distributor from the elements radially inside the distributor.

As shown in the view of Figure 3, the blade 20 is hollow, to allow the passage of a mast 44 radial. In particular, the blades 24 are hollow. These blades 24 make it possible to improve the aerodynamics of the distributor 10, while the radial mast 44 makes it possible to reinforce the structure of the distributor 10.

[0073] The mast 44 is inserted into an opening 22A provided in the inner shroud 22A

As shown in the sectional view of Figure 4, the mast 44 extends through an opening 22A of the internal platform 22, and is inserted into an orifice 30A of the internal shroud 30.

The radial mast 44 can be fixed to the inner shroud 30 by ergotage. For example, the mast can be inserted into the hole 30A provided in the inner shroud 30. The hole 30A can take the form of a blind hole or a notch. An outline of the orifice 30A protrudes so as to form a protrusion surrounding the mast 44. The protrusion around the orifice 30A of the inner shroud 30 and the radial mast 44 each have orifices 52, and the connection between the protrusion and the radial mast 44 is made by inserting a pin 54 through the holes 52 of the protrusion around the hole 30A and the radial mast 44.

In the view of Figure 4, different configurations of mast 44 have been shown, with or without orifice 52, with or without pin 54 for illustration purposes. It will be understood that all or part of the masts 44 may have an orifice 52, and that this orifice 52 is provided for the insertion of a pin 54.

A position holding device 60 is disposed between the inner shroud 30 and the inner platform 22 of the blading 20.

In particular, in the embodiment of Figures 1 and 2, the inner shroud 30 and the inner platform 22 of the blade 20 have surfaces having an extension substantially in the axial direction seen in an axial plane, in particular in the sectional view along the axial plane of Figure 2.

Thus, the position-holding device 60 extends in a substantially radial direction between the inner shroud 30 and the inner platform 22 of the blading 20.

As shown in Figures 1 and 2, the thermal cowling 23 is positioned between the position holding device 60 and the inner platform 22, forming an intermediate piece to improve the distribution of forces between the position holding device 60 and the inner platform 22. The thermal cowling 23 may be absent, and the position holding device 60 can be positioned directly between and in contact with the inner platform 22 and the shroud 30. For this reason, the thermal cowling 23 is not shown in the views of Figures 3, 4, 6A and 6B.

FIG. 5A represents a schematic view of the device for maintaining position 60, and FIG. 5B represents a cross-sectional view of the device for maintaining position 60.

In the embodiment of Figures 5A and 5B, the position holding device 60 is formed by an assembly of two sheets 62 each having a curved shape.

The two sheets 62 meet at two respective ends at two common ends.

The two sheets 62 have an interlocking structure, that is to say that a first sheet 62 is nested in a second sheet 62.

One of the two common ends of the two sheets 62 corresponds to a contact zone 64 between the device for maintaining position 60 and the internal platform 22 of the blade 20, when the device for maintaining position 60 is mounted in distributor 10.

The other of the two common ends of the two sheets 62 corresponds to a contact zone between the device for holding in position 60 and the inner shroud 30, when the device for holding in position 60 is mounted in the distributor 10.

The contact zone 64 between the position holding device 60 and the internal platform 22 of the blading 20, and the contact zone between the position holding device 60 and the internal shroud 30 are formed on the same curved surface of a sheet 62, called the first surface.

The first surface being curved, the normal to the first surface has a variable orientation. In particular, the orientation of the first surface can vary by more than 180° by traversing the first surface between its end corresponding to the contact zone 64 between the device for holding in position 60 and the internal platform 22 of the blading 20, and its end corresponding to the contact zone between the device for holding in position 60 and the internal shroud 30.

[0089] The position holding device 60 is designed to be arranged in an elastically prestressed state between the inner shroud 30 and the inner platform 22 of the blading 20.

Such an elastically prestressed state corresponds for example to a stress exerted in a direction connecting the two contact zones of the device for holding in position 60, in order to cause a deformation bringing these two contact zones closer together.

Such an elastically prestressed state can be achieved by applying a deformation corresponding to a displacement between 0.2 mm and 1 mm, preferably between 0.4 mm 0.8 mm, and preferably 0.6 mm, between a state at rest or not stressed and the elastically prestressed state.

[0092] In particular, the application of a prestress corresponding to the prestressed state can be achieved by mounting the blade 20 between on the one hand the outer shroud 42, and on the other by the inner shroud 30 and the device for holding in position 60. This assembly is carried out when the outer shroud 42, the inner shroud 30 and the device for holding in position 60 are previously mounted in the distributor 10.

In other words, the application of a prestress is carried out by mounting the blade 20 between on the one hand, on an outer part of the blade 20, the outer shroud 42, and on the other hand, on an internal part of the blading 20, the internal shroud 30 and the position holding device 60.

Thus, between an "at rest" or unstressed state, corresponding to the position-holding device 60 shown isolated in FIGS. 5A and 5B, and an elastically prestressed state, a force is applied to the position-holding device 60.

[0095] Figures 5C, 5D, 5E, 5F and 5G show schematic cross-sectional views of alternative position-holding devices 60 . In the embodiments of FIGS. 5C to 5G, only the structure of the position-holding devices 60 vary, the other characteristics of the distributor 10 being otherwise similar to the embodiments of Figures 1-5B and are not repeated.

In particular, a sheet 62 may have a curvature changing orientation, as shown in Figures 5C and 5D. A sheet 62 can also be nested in another sheet 62 as shown in Figures 5B, 5D, or 5G, or two sheets 62 can only be partially nested at a contact zone 64 as in Figures 5E or 5F.

[0097] It is understood that any combination of curvature or nesting can also be considered in order to ensure the application of a force allowing the blading to be maintained in position.

[0098] Figures 6A and 6B show two schematic views of a turbine distributor 10 comprising position holding rings, respectively according to the first and second embodiment, in which an outer part of the distributor 10 comprising the blade 20 , the outer shroud 42 and the radial mast 44 is shown in a sectional view.

The embodiments of Figures 6A and 6B are compatible with the representation of Figures 1 to 5G and the common elements will not be described.

The views of Figures 6A and 6B show the extension of a radial mast 44 between the outer shroud 42 and the inner shroud 30 through the hollow vanes 24.

The embodiments of Figures 6A and 6B differ in the structure of a holding ring in position 68.

[0102] In the first embodiment of a position-holding ring 68 of FIG. 6A, a position-keeping ring 68 is formed from one or more position-keeping devices.

[0103] Position holding ring 68 may be formed of a plurality of independent position holding elements arranged on a circumferential contour of distributor 10.

[0104] The axial positioning of these position-holding devices is ensured by projections 32 intended to rest on the holding device in position. position 60 in an at least axial direction, that is to say having a non-zero axial component.

The tangential positioning of these position-holding devices is ensured by projections 34 intended to rest on the position-holding device 60 in a direction that is at least tangential, that is to say having a tangential component not nothing.

[0106] Position holding ring 68 can also be formed of a single position holding device 60 formed over an entire circumferential contour of distributor 10.

In the second embodiment of a position-holding ring 68 of FIG. 6B, a position-keeping ring 68 is formed from a plurality of position-keeping devices connected circumferentially by one or more junctions 69.

[0108] Thus, the positions of the devices for maintaining in position can be provided to correspond with the circumferential positions of the blades 24, and thus be arranged against each of the plurality of blades 24. Such a ring for maintaining in position 68 has a lightweight structure.

The axial and tangential positioning of the devices for holding the crown in position is ensured by the projections 32, 34.

A plate 62 of the device for maintaining position 60 can be designed in a nickel-based alloy. However, it is understood that the general principle of the device for maintaining position 60 is not limited to such a family of materials.

Although the present invention has been described with reference to specific embodiments, it is obvious that modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the revendications. In particular, individual features of the different illustrated/mentioned embodiments can be combined in additional embodiments. Accordingly, the description and the drawings should be considered in an illustrative rather than restrictive sense. In particular, the present invention has been described in the case of a CMC distributor 10, but it is understood that the general principle of maintaining a blade 20 in position in a distributor 10 is not limited to the use of a material

CMC.

Claims

[Claim 1] Turbomachine distributor (10) extending around an axis (70) and comprising: a blade (20) mounted between an outer shroud (42) and an inner shroud (30), and a holding device in position (60) configured to be disposed in an elastically prestressed state between the inner shroud (30) and an internal platform (22) of the blading (20) in order to exert on the blading (20) a stress oriented towards the outer shroud (42), in which the contact between the inner shroud (30) and the inner platform (22) is made by the same surface (64) of the position-holding device (60).

[Claim 2] A dispenser (10) according to claim 1, wherein the position holding device (60) comprises at least one curved plate (62), preferably two curved plates (62).

[Claim 3] A dispenser (10) according to claim 2, comprising two curved sheets (62) having common ends.

[Claim 4] A distributor (10) according to claim 3, wherein one of the two sheets (62) is nested in the other of the two sheets (62).

[Claim 5] Distributor (10) according to any one of Claims 1 to 4, in which the prestressing is carried out for a compression corresponding to a displacement between 0.2 mm and 1 mm, preferably 0.4 mm and 0.8 mm, preferably 0.6 mm between a state of rest and the elastically prestressed state.

[Claim 6] Distributor (10) according to any one of Claims 1 to 5, in which the prestressing is carried out by mounting the blading (20) on the position-holding device (60) between on the one hand the outer shroud (42) and on the other hand the inner shroud (30).

[Claim 7] Distributor (10) according to claim 6, in which the blading (20) comprises at least one hollow vane (24) to allow the passage of a radial mast (44) securing the inner shroud (30) to the outer shroud (42).

[Claim 8] A dispenser (10) according to claim 6 or 7, wherein the inner shroud (30) has a clamping projection (32) configured to limit movement of the position holding device (60) in a circumferential direction. of the distributor (10).

[Claim 9] A distributor (10) according to claim 7 in combination with claim 6 or 8, comprising at least two position-holding devices (60) connected circumferentially and each disposed against at least one vane (24).

[Claim 10] A distributor (10) according to any one of claims 1 to 9, wherein the vane (20) is made of CMC (ceramic matrix composite).

[Claim 11] Turbomachine comprising the distributor (10) according to any one of claims 1 to 10.