METHOD FOR MANUFACTURING AN ANNULAR PART MADE BY ADDITIVE MANUFACTURING

Abstract

The invention relates to a method for manufacturing an annular part (1) comprising a body (2) and connected to a flange (3), the flange comprising an internal edge (32) for connection to the body, a free external edge (34), and two lateral faces, one of which, called the lower face (38), is connected to a surface (20) of the body, adjacent to the flange, this method comprises: a) producing the annular part by additive manufacturing on a powder bed, an annular support (5) is produced simultaneously with the annular part and connects the lower face of the flange to the surface of the body, this annular support having a lattice structure (50) with cells communicating with each other and having a size greater than that of the powder, and b) removing the powder contained in the lattice structure which is intended to remain permanently on the annular part. Figure for abstract: Fig. 3b

Description

Title of the invention: METHOD FOR MANUFACTURING AN ANNULAR PART PRODUCED BY MANUFACTURING ADDITIVE Field of invention

[0001] The present invention relates to the field of additive manufacturing.

[0002] More particularly, the present invention relates to a method of manufacturing a annular part, such as for an aircraft turbomachine. The present invention also relates to an annular part obtained by such a method and an aircraft turbomachine comprising this annular part. Technical background

[0003] It is known to produce an annular part, in particular for an aircraft turbomachine, by additive manufacturing.

[0004] There are several additive manufacturing technologies and the present application relates in particular to powder bed additive manufacturing. The powder is melted using a high-energy beam, such as a laser beam (LBM process, acronym for Laser Beam Melting). This process consists of shaping metal parts (or alternatively polymer parts) which is opposed to traditional processes by subtraction of material (i.e. by machining). This process makes it possible to selectively consolidate layers of powder in order to constitute, layer by layer, a three-dimensional part.

[0005] The powder bed additive manufacturing process makes it possible to produce parts of complex shape. For example, these parts of complex shape may be bearing supports used in an aircraft turbomachine. These bearing supports make it possible to support one or more bearings for guiding the rotation of a shaft of the aircraft turbomachine.

[0006] [Fig.l] illustrates an example of an annular part 1 that can be produced by additive manufacturing on a powder bed. This annular part 1 is a bearing support for an aircraft turbomachine 10.

[0007] The annular part 1 comprises an annular body 2 extending around an axis A and an annular flange 3 connected to the body 2. This flange 3 is oriented radially towards the outside of the body 2. In the example of [Fig.l], the flange 3 extends along a transverse plane T which is substantially perpendicular to the axis A. The flange 3 comprises a radially internal annular edge 32 for connection to the body 2 and a radially external annular edge 34 which is free. The flange 3 also comprises two lateral annular faces, respectively, upper 36 and lower 38. This lower face 38 is connected, for example by a fillet at the level of the internal annular edge 32, to an annular surface 20 of the body 2 which is adjacent to this annular flange 3.

[0008] In order to be able to produce the annular flange 3, an annular support 5 is used or formed during the additive manufacturing process of the annular part 10. This annular support 5 is generally a solid annular part on which the powder layers forming the flange are formed so as to support the production of the flange. Thus, this annular support is bulky and does not provide any function to the annular part. The annular support is therefore intended to be removed (for example by machining the annular support) so that the annular part can be mounted and operational for example in the aircraft turbomachine.

[0009] Figures 2a and 2b illustrate another example of an annular part 1 comprising the annular flange 3 produced by additive manufacturing using an annular support 5. However, the dimensioning of this annular flange, the annular support can be located in a relatively complex zone Z ([Fig.2b]). This zone Z of the annular part 1 comprises reinforcements 4 connecting the body 2 and the flange 3 and distributed circumferentially around the axis A. In the example, each reinforcement 4 is in the form of a bracket so as to support the flange 3 and connect the flange to the body 2. The removal of the annular support 5 from this zone Z can be more tedious for an operator.

[0010] Another solution would be to use an annular support in cellular form. For example, this cellular annular support comprises cells and bars delimiting each of the cells. However, this cellular annular support can be fragile. For example, some of the bars may be in a void and are therefore not supported by the annular flange, nor by the annular body nor by the lattice structure. These bars in the void can easily be damaged during the manufacture of the annular part (for example by a scraper during a step of spreading the powder layers). Furthermore, powders may be found inside the cells of the cellular annular support which can be sintered during a heat treatment of the process and disadvantage the production of the flange. In addition, the cellular annular support may have physical properties which are incompatible with those of the annular part in operation.So this honeycomb ring support also needs to be removed.

[0011] In these different contexts, it is interesting to propose a solution making it possible to optimize the production of an annular part by additive manufacturing on a powder bed, this part comprising an annular flange. Summary of the invention

[0012] The invention provides a simple, effective and economical solution to the aforementioned drawbacks of the prior art.

[0013] To this end, the invention proposes a method of manufacturing an annular part for a turbomachine, this annular part having a general annular shape around an axis A and comprising an annular body extending around the axis A and connected to an annular flange oriented radially outwards, the annular flange comprising a radially internal annular edge for connection to the annular body, a free radially external annular edge, and two lateral annular faces, one of which, called the lower face, is connected to an annular surface of the annular body, adjacent to the annular flange.

[0014] According to the invention, the method comprises: a) a step of producing the annular part by additive manufacturing on a powder bed, the axis A of the annular part being oriented vertically so that its lower face is oriented downwards, and in that, during additive manufacturing, an annular support is produced simultaneously with the annular part and connects the lower face of the annular flange to the annular surface of the annular body, this annular support having a lattice structure and comprising identical cells which communicate with each other and which have a size greater than that of the powder, and the method further comprising: b) a step of removing the powder contained in the lattice structure, this lattice structure being intended to remain permanently on the annular part.

[0015] Thus, this solution makes it possible to achieve the aforementioned objective. In general, the method according to the invention makes it possible to simplify and optimize the production of an annular part comprising an annular flange, by additive manufacturing on a powder bed.

[0016] In particular, step a) of the method makes it possible to form in one piece and simultaneously the lattice structure of the annular support and the annular flange by additive manufacturing. This makes it possible to produce the lattice structure with the same material as the annular part and to maintain continuity of material between the lattice structure and the annular flange (as well as the annular body). In this way, the lattice structure intended to remain on the annular part has the same physical properties as the annular part so as not to damage the latter, nor its operation, for example in a turbomachine.

[0017] This lattice structure has identical cells which communicate with each other so as to facilitate step b) of de-powdering unfused powders remaining in the cells. This lattice structure not containing unfused powders can thus be kept on the final annular part without hindering its operation.

[0018] The lattice structure according to the configuration of the invention is also less en- bulky for the annular part to be produced, in particular due to the presence of the cells.

[0019] Furthermore, the integration of the lattice structure during step a) makes it possible to support the annular flange during manufacturing and also subsequently during operation of the annular part. Since the annular flange is reinforced by the lattice structure, the thickness of the annular flange can be reduced while retaining its primary function. In this way, the weight of the annular part can be reduced despite the addition of the lattice structure.

[0020] Consequently, the manufacture of the annular part produced by such a method has a consolidated and reliable annular flange. Thus, the mechanical strength of the annular part in general is reinforced.

[0021] The manufacturing method according to the invention may comprise one or more of the following characteristics, taken in isolation from one another or in combination with one another:

[0022] - the lattice structure has a density less than or equal to 30%;

[0023] - the lattice structure is formed by a spatial repetition of identical patterns, each of the patterns comprising bars connected to each other preferably by spheres;

[0024] - each of the patterns forms a pyramid with a triangular base, the sides of which are each formed by a bar and whose vertices are each formed by a sphere;

[0025] - the patterns are of the octet-truss type;

[0026] — each of the patterns has a general cubic shape;

[0027] - the lattice structure comprises an external frustoconical surface which extends from the outer annular edge of the annular flange to the annular body, this outer frustoconical surface being defined by intersecting bars or by a veil covering the lattice structure and formed with the lattice structure during additive manufacturing;

[0028] - the bars have a length L504 of between 0.5 and 1.5 mm, and preferably between 0.7 and 1.1mm, and the spheres have a diameter D between 1 and 3mm, and preferably between 1.5 and 2.5mm;

[0029] - the bars of the lattice structure which are connected to the lower face or to the annular surface of the annular body, are by fillets;

[0030] - the annular flange has a thickness E3 or axial dimension which decreases progressively sively from its inner annular edge to its outer annular edge.

[0031] The invention also relates to an annular part for an aircraft turbomachine obtained by a method according to one of the particularities of the invention, the lattice structure being intended to remain permanently on the annular part.

[0032] The annular part according to the invention may comprise one or more of the following characteristics, taken in isolation from one another or in combination with one another: with others:

[0033] — the annular part has a general annular shape around an axis A and comprising an annular body extending around the axis A and connected to an annular flange oriented radially outwards, the annular flange comprising a radially internal annular edge for connection to the body, a free radially external annular edge, and two lateral annular faces, one of which, called the lower face, is connected to an annular surface of the body, adjacent to the annular flange;

[0034] — the annular part with the lattice structure are made of metal, polymer or ceramics;

[0035] — the annular part is a bearing support(s).

[0036] The invention also relates to an aircraft turbomachine, comprising an annular part according to the invention, this part being for example mounted around rolling bearings of the turbomachine. Brief description of the figures

[0037] The invention will be better understood and other details, characteristics and advantages of the invention will appear more clearly on reading the following description given by way of non-limiting example and with reference to the appended drawings in which:

[0038] [Fig.l] is a schematic perspective view of a first example of an annular part comprising an annular flange according to the prior art,

[0039] [Fig.2a] is a schematic perspective view of a second example of an annular part comprising an annular flange according to the prior art,

[0040] [Fig.2b] is an enlarged schematic perspective view of the annular flange of [Fig.2a],

[0041] [Fig.3a] is a partial schematic and perspective view of a first example of an annular part comprising an annular flange and a lattice structure formed in one piece by additive manufacturing on a powder bed according to the invention,

[0042] [Fig.3b] is an enlarged schematic and perspective view of the annular flange and the lattice structure of [Fig.3a],

[0043] [Fig.4] is a partial schematic and perspective view of the lattice structure of [Fig.3a] or [Fig.3b],

[0044] [Fig.5a] is a schematic perspective view of a pattern of the lattice structure of [Fig.4],

[0045] [Fig.5b] is a schematic perspective view of a mesh of the lattice structure formed by patterns of [Fig.5a],

[0046] [Fig.6a] is a schematic perspective view of a lattice structure according to the invention comprising an external frustoconical surface without reinforcement,

[0047] [Fig.6b] is a schematic perspective view of a lattice structure according to the invention comprising an external frustoconical surface with an example of reinforcement,

[0048] [Fig.6c] is a schematic perspective view of a lattice structure according to the invention comprising an external frustoconical surface with another example of reinforcement,

[0049] [Fig.7a] is a partial schematic view in axial section of an example of a connecting interface between a lattice structure and the annular part according to the invention,

[0050] [Fig.7b] is a partial schematic view in axial section of another example of a connecting interface between a lattice structure and the annular part according to the invention,

[0051] [Fig.8] is a partial schematic and perspective view of a second example of the annular part according to the invention,

[0052] [Fig.9] is a flowchart representing the steps of a manufacturing process of the annular part of [Fig.3a] or [Fig.8] by additive manufacturing on a powder bed,

[0053] [Fig. 10] is a schematic view of a manufacturing apparatus for producing the annular part of [Fig.3a] or [Fig.8].

[0054] Elements having the same functions in different implementations have the same references in the figures. Detailed description of the invention

[0055] By convention, in the description below, the terms "longitudinal" and "axial" qualify the orientation of structural elements extending in the direction of a longitudinal axis (such as that of a turbomachine or an annular part). The terms "radial" or "vertical" qualify an orientation of structural elements extending in a direction perpendicular to the longitudinal axis. The terms "inner" and "outer", and "internal" and "external" are used with reference to a positioning relative to the longitudinal axis. Thus, a structural element extending along the longitudinal axis has an inner face facing the longitudinal axis and an outer surface, opposite its inner surface.

[0056] Figures 1, 2a and 2b have been described in the technical background of the present application and illustrate examples of an annular part for a turbomachine envisaged in the prior art.

[0057] The invention applies in a general and non-limiting manner to different types of annular part 1 of a turbomachine 10, in particular of an aircraft. The turbomachine may be a turboprop or a turbojet.

[0058] The turbomachine may conventionally comprise, from upstream to downstream (relative to the direction of circulation of the gases in the turbomachine), a fan, one or more compressors, an annular combustion chamber, one or more turbines and possibly actually an exhaust nozzle.

[0059] The invention finds an advantageous but not exclusive application in annular parts 1 which can be bearing supports of the turbomachine 10. The bearing support makes it possible to support a bearing (for example a rolling bearing) on which a rotation shaft of the turbomachine rotates (for example a rotation shaft driven by the turbine arranged downstream of the bearing support).

[0060] The annular part 1 of the invention will now be described with reference to FIGS. 3a to 8.

[0061] Figures 3a and 3b illustrate an example of an annular part 1 for supporting bearing(s) intended to be mounted in the turbomachine 10. [Fig.8] illustrates another example of this annular part 1 according to the invention.

[0062] The annular part 1 has a general annular shape around an axis A. This axis A, called longitudinal, extends vertically in the examples of FIGS. 3a and 8. The axis A can be oriented vertically during the manufacture of the annular part 1, and this axis A can be oriented horizontally when the annular part 1 is in operation, for example in the turbomachine 10.

[0063] The annular part 1 comprises an annular body 2 which extends around the axis A. The annular body 2 has an annular surface 20.

[0064] The annular part 1 comprises an annular flange 3 extending around the axis A. The annular flange 3 is oriented radially outwards (relative to the axis A). In the example of Figures 3a, 3b and 8, the annular flange 3 can extend in a transverse plane T which is substantially perpendicular to the axis A. This annular flange 3 is connected to the annular body 2.

[0065] The annular flange 3 comprises a first annular edge 32 radially internal (relative to the axis A) which is also designated by internal annular edge 32, and a second annular edge 34 radially external (relative to the axis A) which is also designated by external annular edge 34. The internal annular edge 32 is connected to the annular body 2. The internal annular edge 32 thus forms an internal edge for connection to the annular body 2. The external annular edge 34 is free (i.e. without attachment to another element) in the example of FIGS. 3a, 3b and 8.

[0066] The annular flange 3 comprises two lateral annular faces, such as an upper face 36 and a lower face 38. The lower face 38 is connected to the annular surface 20 of the annular body 2, at the level of the internal annular edge 32, for example via a fillet. The upper face 36 can also be connected to the annular surface 20.

[0067] In the example of figures 3a and 3b, the annular flange 3 has a first thickness E3 (or in other words an axial dimension measured along the axis A) which decreases progressively from the internal annular edge 32 to the annular edge external 34. Alternatively, the first thickness E3 may be constant from the internal annular edge 32 to the external annular edge 34 ([Fig.8]).

[0068] The annular part 1 may comprise one or more partitions 6. Each partition 6 extends axially from the annular flange 3 to the body 2. In the case of a plurality of partitions 6, they are distributed circumferentially around the axis A. The partitions 6 may delimit between them a cavity 60.

[0069] The annular part 1 comprises an annular support 5 which extends around the axis A. This annular support has the function of supporting the production of the annular flange 3 during an additive manufacturing process on a powder bed (described below).

[0070] The annular support 5 comprises a lattice structure 50. In particular, the annular support 5 may be formed from one or more lattice structures 50. In the configuration of several lattice structures, these lattice structures are preferably distributed circumferentially around the axis A. The lattice structure 50 is intended to remain on the annular part 1, for example in operation in the turbomachine 10.

[0071] Figures 4 to 5b illustrate several non-limiting examples of the lattice structure 50 according to the invention.

[0072] As illustrated in [Fig.4], the lattice structure 50 comprises identical cells 500 which communicate with each other.

[0073] The lattice structure 50 may comprise patterns 502 or be formed by patterns 502. Each of the patterns 502 may comprise bars 504 connected to each other. Each of the cells 500 may thus be delimited by at least two of the bars 504. Preferably, these bars 504 may be connected to each other by a sphere 506.

[0074] [Fig.5a] illustrates an example of pattern 502. Each pattern 502 can form a pyramid with a triangular base for example, the sides of which are each formed by one of the bars 504 and the vertices S are each formed by one of the spheres 506.

[0075] In particular, the lattice structure 50 may be formed by a spatial repetition of identical patterns 502. This spatial repetition of identical patterns 502 may form a mesh M. Several meshes M may be assembled together to form the lattice structure 50. Each mesh M may have a general cubic or octagonal shape. Each mesh M making up the lattice structure 50 may be formed of at least eight patterns 502 of pyramidal shape with a triangular base. Thus, each mesh M may comprise thirty-six bars 504 and fifteen vertices S which may be formed of spheres 506.

[0076] [Fig.5b] illustrates an example of patterns 502 of the “octet-truss” type. These 502 octet-truss patterns (forming each mesh M of the lattice structure 50) therefore have a general cubic shape with a first length L, a height H and a width 1 identical to each other. Each of the first lengths L, heights H or widths 1 of the mesh M is measured between two vertices S of the cubic shape of the mesh M.

[0077] Each mesh M may have a size (for example the first length L) of between 1 and 6 mm. Preferably, the size of each mesh M may be approximately 5 mm.

[0078] The bars 504 may each have a second length L504 of between 0.5 and 1.5 mm. Preferably, the second length L504 of each bar 504 may be approximately 0.9 mm.

[0079] The bars 504 may each have a second thickness E504. Advantageously, a ratio between the second thickness E504 and the first thickness E3 may be between 0.5 and 2. Preferably, this ratio E504 / E3 may be between 0.8 and 1.5. This makes it possible to optimize the mechanical strength between the annular flange and the geometry of the lattice structure.

[0080] For example, the ratio E5o4 / E3 may be 1.5 for a thickness E3 of 1.5 mm of the annular flange 3. This makes it possible to limit the risk of the lattice structure weakening (for example by punching or cracking) the annular flange 3 or the annular surface 20 of the annular body 2.

[0081] The spheres 506 may each have a diameter D of between 1 and 3 mm. Preferably, the diameter D of each sphere 506 may be between 1.5 and 2.5 mm. Even more preferably, the diameter D of each sphere 506 may be approximately 1.8 mm.

[0082] The aforementioned sizes (namely meshes M, bars 504 and spheres 506) may vary depending on the dimensions (size and shape) of the desired lattice structure 50.

[0083] The lattice structure 50 may have a density less than or equal to 30%. By "density", it is meant that this is the volume occupied by the lattice structure, that is to say the sum of the volumes of the branches, divided by the volume of a cube equivalent to the size of the mesh. The annular flange 3 has a solid material and therefore has a density of 100%. Indeed, the cells 500 of the lattice structure 50 make it possible to significantly reduce its weight for a given volume occupied by this lattice structure in the annular part.

[0084] The lattice structure 50 may comprise an external frustoconical surface 52. This external frustoconical surface 52 extends from the second annular edge 34 to the body 2. The external frustoconical surface 52 may be inclined relative to the plane T by an angle α. This angle α may be between 25 and 135°. In the example of [Fig.3b] or [Fig.8], the angle α may be approximately 110°.

[0085] The external frustoconical surface 52 may be formed of intersecting bars 504a (Figures 6b and 6c). This makes it possible to form a reinforcing surface. The bars between crossed bars 504a of [Fig.6c] are denser (i.e. more numerous) than those of [Fig.6b]. The higher the density (or in other words the number) of the crossed bars, the stronger the cohesion between the patterns 502 (and consequently the meshes M). [Fig.6a] illustrates the external truncated cone surface 52 without crossed bars 504a.

[0086] According to another variant, the external frustoconical surface 52 can be formed from a sail 520 covering the lattice structure 50 ([Fig.8]).

[0087] In the examples of Figures 3a, 3b and 8, the lattice structures 50 are located under the annular flange 3. In particular, the lattice structure 50 can be connected to the lower face 38 of the annular flange 3. This lattice structure 50 can be connected to the annular surface 20 of the annular body 2.

[0088] Figures 7a and 7b schematically illustrate a connection interface I between the lattice structure 50 and either the lower face 38 of the annular flange 3 or the annular surface 20 of the body 2. With reference to [Fig.7a], the connection interface I can be produced by at least one of the elements chosen from the bars 504, the vertices S and the spheres 506. With reference to [Fig.7b], the bars 504 can comprise fillets 540. These fillets 540 can connect the bars 504 either to the lower face 38 or the annular surface 20. The presence of the fillets 540 makes it possible in particular to reinforce the connection interface I and to limit the risk of damaging (for example by punching P of the bars 504 illustrated in [Fig.7a]) the lower face 38 or the annular surface 20. Each fillet The connection point may have a radius of, for example, between 0.5 and 1 mm.

[0089] In the example of figures 3a and 3b, the annular part 1 comprises several partitions 6. The lattice structures 50 can be located and formed in the cavities 60.

[0090] In particular, the lattice structure 50 and the annular flange 3 (and therefore also with the body 2) can be formed in one piece (i.e. from one piece) and simultaneously by additive manufacturing on a powder bed.

[0091] The annular part 1 with the lattice structure can be made of metal, polymer or ceramic.

[0092] The present application will now describe a method of manufacturing the annular part 1 described above with reference to FIGS. 3a to 8.

[0093] The manufacturing method 100 is summarized in the flowchart of [Fig.9] whose optional steps are represented in dotted lines.

[0094] The method 100 comprises a first step a) of producing the annular part 1 by additive manufacturing on a powder bed, in which the axis A of the annular part 1 is oriented vertically so that the lower face 38 of the annular flange 3 is oriented downwards. During this step a), the annular support 5 having the lattice structure 50 is produced simultaneously with the annular part 1 and connects the face lower 38 of the annular flange 3 to the annular surface 20 of the body 2. As described above, the cells 500 of the lattice structure 50 communicate with each other. In addition, these cells 500 have a size greater than that of the powder used by additive manufacturing.

[0095] In particular, the method 100 may comprise a preliminary step i) of producing a digital production file using suitable software. This digital file is for example produced from a cutting into slices of given thickness from CAD software (abbreviation for Computer Aided Design) of an annular part. The digital file comprises a set of instructions, such as laser trajectories, so that a manufacturing apparatus 7 can produce, slice by slice, the annular part.

[0096] Application WO-A1-2020 / 234526 filed by the applicant describes an example of a manufacturing apparatus and a method for additive manufacturing on a powder bed of a part which can be used to carry out, for example, step a) of the method 100 of the invention.

[0097] [Fig. 10] illustrates an example of a manufacturing apparatus 7 which may comprise: - a manufacturing plate 70 serving as support for the production of the annular part 1, - a feed member 72 for supplying powder 73 of a desired material onto the manufacturing plate 70, - a spreading member 74 for powder 73 on the manufacturing plate 70, - a laser beam generator 76 configured to generate a laser beam 78 intended to scan the layer(s) of Cb C2 powder for the purpose of localized melting of the powder and the manufacture of the annular part 1 layer by layer.

[0098] By way of example, step a) may comprise a step of depositing powder 73 of the desired material on the manufacturing plate 70. The powder 73 deposited on the manufacturing plate 70 forms a powder bed. The powder feed member 72 may be a feed bin containing powder 73 of the desired material or a nozzle depositing the powder 73 of the desired material on the manufacturing plate 70.

[0099] Step a) may comprise a step a2) of spreading powder 73 in a layer of powder Ci, C2 of the desired material on the manufacturing plate 70 with a desired thickness. The spreading member 74 may be a roller or a scraper which can move in translation on either side of the powder bed.

[0100] After deposition of a first layer of powder Ci, step a) may comprise a selective scanning step a3) of certain zones of the first layer of powder Ci corresponding to a slice of the annular part 1 to be produced. The scanning may be carried out by one or more lasers of the generator 76 of laser beam 78. The scanning pattern and the lasing parameters (such as the laser power, the speed of scanning, the spacing between two laser passes, etc.) are dictated to the manufacturing device 7 by the digital file. Scanning makes it possible to raise the first layer of powder Ci to a temperature higher than the melting temperature of the desired material making up the powder bed to form a molten bath. This molten bath, upon cooling, consolidates and forms a solid bead. At the end of the scanning step, a two-dimensional section of a part of the annular part 1 to be produced is obtained.

[0101] The steps of deposition aj, spreading a2) and scanning a3) can be repeated as many times as necessary to produce the final annular part 1. This therefore makes it possible to deposit and spread a new layer of secondary powder C2 (or following) over the previous layer of powder and a new scan can be carried out in order to consolidate a new section of the annular part to be produced. Thus, iteratively, a three-dimensional part is reconstituted by successive consolidation of two-dimensional sections.

[0102] As described previously, the first thickness E3 of the annular flange 3 can decrease progressively from the internal annular edge 32 to the external annular edge 34. This makes it possible in particular to manufacture the annular flange progressively and thus avoid fusing a large surface area of powder layer onto the lattice structure.

[0103] With the integration of the lattice structure 50 during step a), the first thickness E3 of the annular flange 3 can be reduced by 50% while optimally retaining the functional and design aspects of this annular flange.

[0104] As described above, the lattice structure 50 may comprise the outer frustoconical surface 52. This outer frustoconical surface 52 defined by the intersecting bars 504b or the web 520 may be formed with the lattice structure 50 during step a).

[0105] The method 100 comprises a second step b) of removing the powder contained in the lattice structure 50, this lattice structure being intended to remain permanently on the annular part 1.

[0106] Step b) makes it possible to remove the so-called unfused powders from the annular part 1, and in particular from the cells 500 of the lattice structure. This step b) can be carried out manually by an operator by sweeping and vacuuming the unfused powders. Alternatively, a machine suitable for depowdering unfused powders can also be used to carry out step b).

[0107] In the case of [Fig.8], the annular flange 3 and / or the external frustoconical surface 52 of the lattice structure 50 may comprise holes so as to evacuate these unfused powders.

[0108] In the present application, the annular part 1 is described with reference to a support bearing (for example that of a rolling bearing) of the turbomachine 10. However, the annular part 1 of the invention may be any other type of annular part for a turbomachine with an annular flange obtained by additive manufacturing on a powder bed.

Claims

Claims

1. Method for manufacturing (100) an annular part (1) for a turbomachine (10), this annular part (1) having a generally annular shape around an axis (A) and comprising an annular body (2) extending around the axis (A) and connected to an annular flange (3) oriented radially outwards, the annular flange (3) comprising a radially internal annular edge (32) for connection to the annular body (2), a free radially external annular edge (34), and two lateral annular faces, one of which, called the lower face (38), is connected to an annular surface (20) of the annular body (2), adjacent to the annular flange (3), characterized in that it comprises: a) a step of producing the annular part (1) by additive manufacturing on a powder bed, the axis (A) of the annular part being oriented vertically so that its lower face (38) is oriented towards the bottom, and that, during additive manufacturing,an annular support (5) is produced simultaneously with the annular part (1) and connects the lower face (38) of the annular flange (3) to the annular surface (20) of the annular body (2), this annular support (5) having a lattice structure (50) and comprising identical cells (500) which communicate with each other and which have a size greater than that of the powder, the method further comprising: b) a step of removing the powder contained in the lattice structure (50), this lattice structure being intended to remain permanently on the annular part (1).,

2. The method of claim 1, wherein the lattice structure (50) has a density less than or equal to 30%.

3. A method according to claim 1 or 2, wherein the lattice structure (50) is formed by a spatial repetition of identical patterns (502), each of the patterns (502) comprising bars (504) connected to each other preferably by spheres (506).

4. Method according to claim 3, in which each of the patterns (502) forms a pyramid with a triangular base, the sides of which are each formed by a bar (504) and the vertices (S) of which are each formed by a sphere (506).

5. A method according to claim 3 or 4, wherein the patterns (502) are of the octet-truss type.

6. A method according to one of claims 3 to 5, wherein the lattice structure (50) comprises an outer frustoconical surface (52) which extends from the outer annular edge (34) of the annular flange to the annular body (2), this outer frustoconical surface (52) being defined by intersecting bars (504a) or by a web (520) covering the lattice structure (50) and formed with the lattice structure (50) during additive manufacturing.

7. Method according to one of claims 3 to 6, in which the bars (504, 504a) have a length (L504) of between 0.5 and 1.5mm, and preferably between 0.7 and 1.1mm, and the spheres (506) have a diameter (D) of between 1 and 3mm, and preferably between 1.5 and 2.5mm.

8. Method according to one of claims 3 to 7, in which the bars (504) of the lattice structure (50) which are connected to the lower face (38) or to the annular surface (20) of the annular body (2), are connected by connecting fillets (540).

9. A method according to any preceding claim, wherein the annular flange (3) has a thickness (E3) or axial dimension which progressively decreases from its inner annular edge (32) to its outer annular edge (34).

10. Annular part (1) for a turbomachine (10), in particular an aircraft, obtained by a method (100) according to one of the preceding claims, the lattice structure (50) being intended to remain permanently on the annular part (1).

11. Turbomachine (10), in particular for an aircraft, comprising an annular part (1) according to claim 10, this annular part (1) being for example mounted around rolling bearings of the turbomachine.

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