Turbomachine component comprising at least one blade obtained by additive manufacturing

Abstract

The present invention relates to a turbomachine element (1), comprising at least one blade (2) obtained by additive manufacturing, the blade (2) having a skin (4) and an internal lattice (6) allowing air circulation within the blade (2) and serving as a support for the additive manufacturing of the skin (4). Figure for the abstract: Fig. 6

Description

Title of the invention: Turbomachine element comprising at least one blade obtained by additive manufacturing FIELD OF THE INVENTION

[0001] The present invention relates to the field of turbomachines and more particularly to systems for cooling turbomachine elements STATE OF THE ART

[0002] Within a turbomachine, the parts are subjected to very high thermal stresses. To prevent certain elements from breaking or wearing out prematurely, it is necessary to cool them during the operation of the turbomachine.

[0003] This is particularly the case for high pressure distributors, inlet guide vanes, and variable stator vanes.

[0004] Currently, several methods of cooling these elements are known, including:

[0005] - Multi-drilled insert (impact): With this technology (shown on the Figures 1 and 2), the ventilation air is guided at high speed through holes (impact holes made in an insert) on the part to be ventilated.

[0006] - Internal serpentine type circuit: With this technology (shown in [Fig.3]), The ventilation air is guided through the room to be cooled in order to achieve convective exchange. It is evacuated into the main vein (hot gas) via vents.

[0007] - Disruptors (bridges / fins): With this technology (shown in [Fig.4]), The ventilation air path can be partially obstructed by disruptors in order to achieve local heat exchanges between the disruptors and the ventilation air (+acceleration of the air to increase convective exchange). These disruptors can also be used to thermally connect the intrados and the extrados of a blade.

[0008] Furthermore, it is known from document FR3085713 to integrate cooling capillaries into a blade (or vane). These capillaries pass through the vane and thus allow air to circulate through the vane.

[0009] This system allows efficient cooling but is not optimal in the case of production of the element (blade, vane or distributor) by additive manufacturing.

[0010] Indeed, since a blade (or a vane) can be a hollow part, when it is produced using additive manufacturing, it may be necessary to integrate a manufacturing support into the blade. Depending on the manufacturing direction, the support allows the deposited material to be supported, for example to produce one of the external faces of the blade.

[0011] However, for many elements of a turbomachine, additive manufacturing by laser fusion on a powder bed requires a manufacturing direction along the axis of the turbine. In this context, a blade with many deviations and hollowed out cannot be produced in a single piece without supports. It is therefore essential to add manufacturing supports in the blade. However, these supports, which are not initially planned, can interfere with the capillaries, and potentially degrade the intrinsic performance of the part. In addition, some unsupported capillaries can be obstructed and inaccessible at the end of the additive manufacturing process.

[0012] In this context, it is necessary to provide a turbomachine element comprising a blade having a structure suitable for being cooled and for being produced by additive manufacturing. Statement of the invention

[0013] According to a first aspect, the invention proposes a turbomachine element, comprising at least one blade obtained by additive manufacturing, the blade having a skin and an internal lattice allowing air circulation in the blade and having a function of supporting additive manufacturing of the skin.

[0014] The lattice may have a variable density.

[0015] The mesh may have a greater density near the skin.

[0016] The blade may have at least one insert positioned in the lattice.

[0017] The insert may have at least one opening allowing air circulation towards the skin.

[0018] The lattice may comprise an inner portion and an outer portion, separated by the insert.

[0019] The element may have two circumferential vein walls between which said at least one blade extends radially, the skin forming two tangential walls of said at least one blade.

[0020] The blade may have openings in a radial plane.

[0021] The blade may not have a wall in a radial plane.

[0022] The element can be chosen from a high pressure distributor, an inlet guide vane, a variable stator vane. DESCRIPTION OF FIGURES

[0023] Other characteristics, aims and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting, and which must be read in conjunction with the appended drawings in which:

[0024] [Fig. 1] [Fig. 1] is a representation of a prior art device.

[0025] [Fig.2] [Fig.2] is a representation of a prior art device.

[0026] [Fig.3] [Fig.3] is a representation of a prior art device.

[0027] [Fig.4] [Fig.4] is a representation of a prior art device.

[0028] [Fig.5] [Fig.5] is a representation of a known additive manufacturing device.

[0029] [Fig.6] [Fig.6] is a radial sectional representation, substantially perpendicular dicular to the flow intended to flow around the blade, of a blade according to the invention.

[0030] [Fig.7] [Fig.7] is an exploded representation of a blade according to the invention.

[0031] [Fig.8] [Fig.8] is an enlarged representation of a portion of a blade according to the invention.

[0032] [Fig.9] [Fig.9] is a sectional representation, in a substantially circumferential plane ferential, of a portion of a blade according to the invention. DETAILED DESCRIPTION OF THE INVENTION

[0033] Context of a turbomachine

[0034] According to a first aspect, the invention proposes a turbomachine element 1, comprising at least one blade 2 obtained by additive manufacturing.

[0035] The turbomachine may be, for example, a dual-flow aircraft turbojet engine well known to those skilled in the art, conventionally comprising a fan, a compressor, a combustion chamber, a high-pressure turbine, and a low-pressure turbine. In the case of dual-flow turbomachines, the fan has large dimensions compared to the other components, and the airflow passing in particular through the combustion chamber and the high- and low-pressure turbines represents a small portion of the total airflow passing through the fan. Part of the airflow passing through the fan is therefore directly expelled, while another part passes through the compressor, the combustion chamber, and the high- and low-pressure turbines.

[0036] Pale

[0037] As indicated previously, the invention relates to an element 1 comprising a blade 2. Typically, the blade 2 has a skin 4 and a lattice 6. It is specified that in usage conditions, the blade 2 is intended to be cooled by air or a gas colder than the hot gases circulating in a vein of the turbomachine.

[0038] The skin 4 is an external envelope of the blade 2. In a conventional manner, the blade 2 has a geometry with a leading edge 7, a trailing edge 8, a lower surface 10 and an upper surface 12. As will be described below, the blade 2 according to the invention is preferably manufactured using an additive manufacturing process.

[0039] Thus, all of the elements constituting the blade 2 (the skin, the lattice and the insert which will be presented below) are produced using additive manufacturing and are linked to each other so as to form a single, single-piece part.

[0040] In other words, the blade 2 manufactured by additive manufacturing is not made up of several assembled parts, but is a single-piece part comprising several elements.

[0041] In particular, the blade 2 comprises an internal lattice 6 linked to the skin 4. The lattice 6 makes it possible to support the skin 4 to guarantee the mechanical resistance of the blade 2.

[0042] In addition, as will be described below, the lattice 6 allows air to circulate in the blade 2 and has a function of supporting the additive manufacturing of the skin 4. This dual function of the lattice 6 is a particularly advantageous technical arrangement of the invention. Indeed, the lattice 6 is an economical manufacturing support because it has empty zones and therefore requires less material for its manufacture than a solid element. In addition, the use of a lattice 6 as a framework for the blade 2 makes it possible to both guarantee the mechanical strength of the blade while allowing optimal internal cooling. Indeed, since the lattice 6 has numerous empty zones 14, air can circulate satisfactorily in the lattice.

[0043] It is specified that by lattice 6, it is understood a lattice structure, that is to say an architectural structure composed of a material and empty zones. In other words, the lattice is a mesh of material (typically a metal alloy) consisting of a network of solid structures 16 (for example in metal alloy) and empty zones 14 between the structures. By empty zone 14, it is understood zones without solid material consolidated by additive manufacturing. More precisely, in these empty zones 14, powder is deposited during manufacturing. But, this powder is not fused, then is removed at the end of manufacturing. Typically the empty zones 14 are filled with a gas making up the atmosphere in which the lattice 6 is located. Typically, during manufacturing the empty zones 14 can be filled with a neutral gas or ambient terrestrial air (i.e. a gas mixture composed essentially of nitrogen, carbon dioxide and oxygen).

[0044] Advantageously, the lattice 6 may have a variable density. By variable density, it is understood that the quantity of material and the dimensions of the mesh vary in the lattice. Thus, an area of ​​greater density is an area in which (compared to the rest of the lattice) there is a higher concentration of solid structures 16 and a lower concentration of empty areas 14. Conversely, an area of ​​lower density is an area in which (compared to the rest of the lattice) there is a lower concentration of solid structures 16 and a higher concentration of empty areas. In other words, in an area of ​​lower density (compared to the rest of the lattice), the volume of an empty area is greater than the volume of an empty area in an area of ​​higher density.

[0045] According to a particularly advantageous arrangement, the lattice 6 can have a higher density near the skin 4. This arrangement makes it possible to guarantee optimal air circulation in the blade, while providing optimal mechanical support to the skin and participating in thermal exchanges.

[0046] Insert

[0047] According to a particularly advantageous arrangement, the blade may comprise an insert 20 positioned in the lattice 6.

[0048] With reference to [Fig.7] the insert 20 may be a solid element (unlike the lattice). By solid element, it is understood that the insert 20 has solid walls made of solid materials (with the exception of openings made in the insert as will be described below).

[0049] Typically, the insert 20 has a geometry similar to the geometry of the blade 2. Thus, the insert 20 has a wing geometry with a leading edge, a trailing edge, a lower surface and an upper surface. The insert has a hollow radial section and defines an interior volume 22.

[0050] As indicated previously, the insert 20 may have at least one opening 21 allowing air to circulate towards the skin. Preferably, the insert 20 has a plurality of openings 21. The openings 21 pass through the wall of the insert to allow air to circulate from the interior volume to the exterior.

[0051] The insert 20 is manufactured and positioned in the lattice 6, so that it divides the lattice 6 into an internal portion 61 positioned inside the insert 6 and an external portion 62 located outside the insert 20. It is specified that in [Fig.7] the insert 20 and the lattice 6 are shown separate. However, this is an exploded representation allowing only each element to be observed separately. Indeed, the lattice 6 and the insert 20 are manufactured at the same time and are linked so as to form a single piece (with the skin 4 as well).

[0052] As shown in [Fig.8] the openings 21 of the insert 20 are positioned so as to open into empty zones 14 of the mesh 6, to allow the most optimal air circulation possible.

[0053] In addition, the element may have two circumferential vein walls 24 between which said at least one blade extends radially, the skin forming two tangential walls of said at least one blade.

[0054] These vein walls each define a radial opening. Thus, the blade has openings in a radial plane.

[0055] The vein walls 24 act as radial stops framing the lattice. Thus, in other words, the blade is hollow along the radial axis and may not have a wall in a radial plane.

[0056] According to a particularly advantageous arrangement, the blade 2 does not have a wall in a radial plane. Thus, air can enter the blade 2 (as represented by arrow IV) and circulate there via the mesh 6 and the openings of the insert, to cool the skin.

[0057] Typically, the element is chosen from a high pressure distributor, an inlet guide vane, a variable stator vane.

[0058] Manufacturing process

[0059] According to a second aspect, the invention relates to a method of additive manufacturing of an element according to the invention.

[0060] Typically, the additive manufacturing process is a laser powder bed fusion process (also called LBM Laser Beam Melting or SLM Selective Laser Melting). This is a raw material production process that is part of the family of additive manufacturing processes.

[0061] In a known manner, an LBM process uses an additive manufacturing machine A (shown in [Fig.5]) integrating a laser B, a mirror C, a scraper D, a powder tank E and a manufacturing plate F.

[0062] The LBM process takes place in different stages which are repeated until the final object is obtained:

[0063] - A layer of metal powder is spread using a scraper on the manufacturing platform. The powder is locally fused by a laser The build plate descends by the thickness of one layer A new layer of metal powder is spread and so on

[0064] As indicated previously, with this process, the different constituent parts (skin, mesh and insert) are manufactured simultaneously layer by layer, to form a single single piece.

[0065] During the manufacturing process, the mesh supports the skin and the insert. Thus, as explained above, the mesh has a dual function of support during manufacturing and mechanical structure contributing to the strength and cooling of the element.

[0066] Turbomachine

[0067] According to another aspect, the invention relates to a turbomachine comprising a regulation assembly 10.

[0068] Aircraft

[0069] According to another aspect, the invention relates to an aircraft comprising at least one turbomachine.

Claims

Claims

1. Turbomachine element (1), comprising at least one blade (2) obtained by additive manufacturing, the blade (2) having a skin (4) and an internal lattice (6) allowing air circulation in the blade (2) and having a function of supporting additive manufacturing of the skin (4).

2. Element (1) according to claim 1, in which the mesh (6) has a variable density.

3. Element (1) according to claim 2, in which the mesh (6) has a greater density near the skin (4).

4. Element (1) according to any one of the preceding claims, in which the blade (2) has at least one insert (20) positioned in the lattice (6).

5. Element (1) according to claim 4, in which the insert (20) has at least one opening (21) allowing air circulation towards the skin (4).

6. Element (1) according to any one of claims 4 or 5, in which the mesh (6) comprises an internal portion (61) and an external portion (62), separated by the insert (20).

7. Element (1) according to any one of the preceding claims having two circumferential vein walls (24) between which said at least one blade (2) extends radially, the skin (4) forming two tangential walls of said at least one blade (2).

8. Element (1) according to claim 7, in which the blade (2) has openings in a radial plane.

9. Element (1) according to claim 8 in which the blade (2) does not have a wall in a radial plane.

10. Element (1) according to any one of the preceding claims, characterized in that the element (1) is chosen from a high pressure distributor, an inlet guide vane, a variable stator vane.

Images