FR3110630A1 - TURBOMACHINE OUTPUT DIRECTOR VANE, MADE FROM SEVERAL PARTS ASSEMBLED BETWEEN THEM - Google Patents

Abstract

The invention relates to a guide vane arranged in an air flow of a fan (15) of a dual-flow aircraft turbomachine, the vane being produced using an upper surface body (32a) and an intrados body (32b) between which is arranged a thermal conduction matrix (80). In addition, the means for fixing the two bodies (32a, 32b) are arranged outside the aerodynamic part (32) of the blade, and the upstream and downstream parts (63, 61) respectively forming the leading edge ( 64) and the trailing edge (62) are mounted at the ends of the bodies (32a, 32b). Figure for abstract: Figure 3

Description

OUTLET GUIDE VANE FOR TURBOMACHINE, MADE FROM SEVERAL PARTS ASSEMBLED TOGETHER

The present invention relates to the field of dual-flow aircraft turbomachines, and in particular to the design of guide vanes arranged in all or part of an airflow of a fan of the turbomachine.

These are preferably outlet guide vanes, also referred to as OGVs (Outlet Guide Vane), designed to straighten the flow of air at the outlet of the fan. Alternatively or simultaneously, guide vanes could, if necessary, be placed at the inlet of the fan. The guide vanes are conventionally arranged in the secondary stream of the turbomachine.

The invention preferably relates to an aircraft turbojet equipped with such outlet guide vanes.

STATE OF THE PRIOR ART

On certain turbofan engines, it is known to install outlet guide vanes downstream of the fan to straighten the flow escaping from it, and also possibly to fulfill a structural function. This last function aims in fact to allow the passage of the forces from the center of the turbomachine, towards an outer shroud located in the extension of the fan casing. In this case, an engine attachment is conventionally arranged on or close to this outer shroud, to ensure attachment between the turbine engine and an aircraft engine mount.

Recently, it has also been proposed to assign an additional function to the outlet guide vanes. This is a heat exchanger function between the outside air passing through the ring of outlet guide vanes, and the lubricant circulating inside these vanes. This heat exchanger function is for example known from document US 8 616 834, or from document FR 2 989 110.

The lubricant intended to be cooled by the outlet guide vanes can come from different zones of the turbomachine. It may in fact be a lubricant circulating through the lubrication enclosures of the rolling bearings supporting the engine shafts and/or the fan hub, or even a lubricant dedicated to the lubrication of the mechanical transmission elements of the accessory box (AGB “Accessory Geared Box”). Finally, it can also be used to lubricate a fan drive reduction gear, when such a reduction gear is provided on the turbomachine in order to reduce the speed of rotation of its fan.

Growing lubricant needs require the heat dissipation capacity to be adapted accordingly, associated with the exchangers intended for cooling the lubricant. Assigning a role of heat exchanger to the outlet guide vanes, as in the solutions of the two documents cited above, makes it possible in particular to reduce or even eliminate conventional exchangers of the ACOC type (from the English " Air Cooled Oil Cooler”). These ACOC exchangers being generally arranged in the secondary stream, their reduction/removal makes it possible to limit the disturbances of the secondary flow, and thus to increase the overall efficiency of the turbomachine.

Within the internal lubricant cooling passage, it is possible to install obstacles to the circulation of the lubricant, such as studs intended to disrupt the flow and increase the wetted surface, in order to ensure better heat exchange.

However, the realization of this type of blade can prove to be difficult, even impossible with certain techniques nevertheless considered interesting. This is, for example, additive manufacturing, also called 3D printing or direct manufacturing, which may prove to be unsuitable for the production of a single piece of the blade integrating the matrix, in particular when this blade has dimensions that are too large. and/or a network of studs with a geometry unsuitable for additive manufacturing.

To address this problem, it was proposed to produce the blade in several distinct parts, so as to facilitate its manufacture and to limit the aerodynamic losses on the flow crossing this blade. Such a solution is for example known from document FR 3 077 850 A1.

Nevertheless, there remains a need to optimize the design of such blades, so as to achieve an even better compromise in terms of aerodynamic performance, ease of manufacture, and dissociation of the various functions of the blade.

To meet this need, the subject of the invention is first of all a guide vane intended to be arranged in all or part of an air flow of a dual-flow aircraft turbomachine fan, the director comprising an aerodynamic flow straightening part intended to be embraced by said all or part of the fan air flow, said blade being produced using:
- an underside body defining at least a part of an underside surface of the aerodynamic part, the underside body comprising at least a first head fixing member intended for fixing the blade on a outer casing element, as well as at least one first root fixing member intended for fixing the blade to an inner casing element;
- an extrados body defining at least a part of an extrados surface of the aerodynamic part, the extrados body comprising at least one second head fixing member intended for fixing the blade on the outer casing element, as well as at least one second foot fixing member intended for fixing the blade on the inner casing element;
- a thermal conduction matrix arranged in a space delimited between the intrados and extrados bodies, said matrix being intended to be traversed by lubricant and incorporating obstacles to the circulation of lubricant; And
- means for fixing the intrados body to the extrados body, these means comprising first fixing means arranged radially outwards with respect to the first and second head fixing members, and second fixing means arranged radially inward relative to the first and second foot attachment members.

According to the invention, the blade is also produced using an upstream part forming a leading edge of the blade, attached fixedly to at least one of the lower and upper surfaces, and a downstream part forming a trailing edge of the blade, attached fixedly to at least one of the lower and upper surfaces.

The invention thus provides a solution making it possible to facilitate its manufacture, while presenting high aerodynamic performance, and being capable of dissociating the various functions of the blade. Indeed, the manufacture of the blade is made easy by the multiplicity of components adopted, these components each being able to be produced by conventional techniques, even for blades of large dimensions. In addition, the fact of deporting all or part of the fastening means of these components outside the aerodynamic part of the blade, avoids the degradation of the aerodynamic flow crossing the blade. Finally, the separation of the leading and trailing edges, with respect to the lower and upper surfaces, constitutes an additional degree of freedom in the design of the blade, which proves to be particularly advantageous. Indeed, these leading edge and trailing edge zones have a decisive character in the overall aerodynamic performance of the blade, as well as in terms of overall mechanical resistance due to the exposure of the leading edge to hailstones, birds and any other objects. Consequently, by being dissociated from the rest of the blade, the leading edge and the trailing edge can be the subject of specific choices from a material point of view, but also from an aerodynamic point of view in an to make the surfaces the most efficient in terms of roughness, undulation and shape. In addition, the leading edge being more subject to impacts and erosion than the other parts of the blade, it is thus possible to replace it without replacing these other parts of the blade.

The invention thus offers a satisfactory compromise responding effectively to the problem posed, in particular by ensuring a separation of the thermal, aerodynamic and possibly structural functions of the blade, while dissociating the leading edge and the trailing edge of the other constituent elements of dawn.

The invention therefore allows easier manufacture, reduced cost and increased aerodynamic performance.

The invention preferably provides at least one of the following optional features, taken alone or in combination.

Preferably, the upstream part and the downstream part are each made of a material different from that of the material(s) constituting the intrados and extrados bodies, and each preferably made of titanium or a titanium alloy. The same material can be used for the two upstream and downstream parts, or different materials.

The upstream part and the downstream part are each bonded to at least one of the intrados and extrados bodies, and/or fixed to at least one of the intrados and extrados bodies using said first and second fixing means, preferably by being traversed by these means. Alternatively, other fixing means could be provided, preferably outside the vein, which would be added to the first and second means, and which would therefore not participate in the fixing of the two intrados and extrados bodies. one over the other. These other fixing means could be provided alone, or in combination with the glue. These upstream and downstream parts can simultaneously or alternately be brazed or welded to the other blade parts.

According to a first preferred embodiment of the invention, the upstream part has a downstream end forming a break in thickness defining a step, the upstream part extending along a spanning direction of the blade and being superimposed on a upstream end of the assembly formed by the intrados and extrados bodies, and/or the downstream part has an upstream end forming a break in thickness defining a step, the downstream part extending in the span direction of the blade and being superimposed on a downstream end of the assembly formed by the lower and upper surfaces.

According to a second preferred embodiment of the invention, the upstream part has a general U or V shape, one of the branches of the U/V of which forms an upstream end of the lower surface of the blade, and of which the other branch of the U/V forms an upstream end of the upper surface of the blade, and/or the downstream part has a general U or V shape, of which one of the branches of the U/ V forms a downstream end of the lower surface of the blade, and the other branch of the U/V forms a downstream end of the lower surface of the blade.

In this second preferred embodiment, each branch of U/V preferably has a free end with a break in thickness defining a step of reduced thickness, the step being oriented towards the inside of the blade, or towards the dawn exterior. It is noted that a “downward” step in the direction of the flow is less aerodynamically penalizing than an “upward” step.

Preferably, the hollow defined internally by each U/V accommodates one end of the thermal conduction matrix. This type of interlocking makes it possible to further reinforce the mechanical resistance of the blade.

Preferably, whatever the embodiment envisaged, said first fastening means and said second fastening means comprise bolts passing through passage orifices made through the intrados and extrados bodies. Alternatively or simultaneously, these fixing means can be of the welding, brazing or even gluing type.

Preferably, said thermal conduction matrix comprises a lubricant-tight outer sheath, arranged in said space delimited between the intrados and extrados bodies. According to an alternative embodiment, the blade includes a lubricant sealing device, arranged between the lower and upper surfaces. This arrangement is retained in particular when the matrix used has a permeable character.

Preferably, said space housing the thermal conduction matrix has the general shape of a U defining two lubricant passages connected to each other by an elbow. Alternatively, the space could define a single passage, or two passages intended to be connected to each other outside the dawn.

Preferably, the thermal conduction matrix is made in one piece, or else using several distinct matrix elements arranged end-to-end or spaced from each other.

The invention also relates to an aircraft turbomachine, preferably a turbojet, comprising a plurality of guide vanes such as that described above, these vanes being arranged downstream or upstream of a fan of the turbomachine. In addition, the first and second attachment means are arranged outside of said all or part of the fan air flow, preferably delimited by at least one aerodynamic wall arranged between the outer and inner casing elements.

Finally, the subject of the invention is a method for manufacturing a blade as described above, comprising the following steps:
- production of the intrados and extrados bodies and of said thermal conduction matrix, as well as upstream and downstream parts respectively forming the leading edge and the trailing edge;
- Fixing the intrados body on the extrados body, using the first and second fixing means, and fixing the upstream and downstream parts on the intrados/extrados bodies.

Preferably, the thermal conduction matrix is produced independently of the intrados and extrados bodies, and more preferably by the additive manufacturing technique.

Alternatively, at least part of the thermal conduction matrix can be made in one piece with at least one of the intrados and extrados bodies. For example, all the obstacles of the matrix can be made in one piece with one of the intrados and extrados bodies. According to another example, part of these obstacles can be made in one piece with one of the intrados and extrados bodies, and the other obstacles made in one piece on the other of these two bodies. .

Other advantages and characteristics of the invention will appear in the non-limiting detailed description below.

This description will be given with regard to the appended drawings, among which;

shows a schematic side view of a turbojet engine according to the invention;

shows an enlarged, more detailed view of an outlet guide vane of the turbojet engine shown in the preceding figure, the vane being presented according to a first preferred embodiment of the invention;

corresponds to a sectional view taken along the line III-III of Figure 2;

is a view similar to that of FIG. 3, showing an alternative embodiment;

shows a perspective view of part of the blade shown in the preceding figures;

represents a perspective view of the upper surface body forming part of the blade shown in the preceding figures;

represents a perspective view similar to the previous one, from another angle of view;

shows a perspective view of the lower surface body forming part of the blade shown in the preceding figures;

represents a perspective view similar to the previous one, from another angle of view;

is a schematic view in longitudinal section of part of the turbojet engine comprising the blade shown in the preceding figures; And

is a view similar to that of FIG. 9, according to an alternative embodiment;

in the preceding figures;

is a perspective view similar to that of the previous figure, with the upstream part of the blade being in the form of an alternative embodiment;

is a partial perspective view of a downstream part of the blade shown in the preceding figures;

is a perspective view similar to that of the previous figure, with the downstream part of the blade being in the form of an alternative embodiment;

shows a sectional view similar to that of FIG. 3, with the blade in the form of a second preferred embodiment of the invention;

shows an enlarged view of the upstream part of the blade shown in FIG. 15;

shows an enlarged view of the downstream part of the blade shown in FIG. 15;

presenting in the form of an alternative embodiment; And

shows an enlarged view of the upstream part of the blade shown in figure 18.

DETAILED DISCUSSION OF PREFERRED EMBODIMENTS

Referring to Figure 1, there is shown a bypass turbojet engine 1 and double body, having a high bypass ratio. The turbojet engine 1 conventionally comprises a gas generator 2 on either side of which are arranged a low pressure compressor 4 and a low pressure turbine 12, this gas generator 2 comprising a high pressure compressor 6, a combustion chamber 8 and a high-pressure turbine 10. Subsequently, the terms "front" and "rear" are considered in a direction 14 opposite to the main direction of gas flow within the turbojet, this direction 14 being parallel to the axis longitudinal 3 thereof. On the other hand, the terms "upstream" and "downstream" are considered according to the main direction of gas flow within the turbojet.

The low pressure compressor 4 and the low pressure turbine 12 form a low pressure body, and are connected to each other by a low pressure shaft 11 centered on the axis 3. Similarly, the high pressure compressor 6 and the high pressure turbine 10 form a high pressure body, and are connected to each other by a high pressure shaft 13 centered on the axis 3 and arranged around the low pressure shaft 11. The shafts are supported by bearings bearing 19, which are lubricated by being arranged in oil chambers. The same is true for the fan hub 17, also supported by rolling bearings 19.

The turbojet engine 1 also comprises, at the front of the gas generator 2 and of the low pressure compressor 4, a single fan 15 which is here arranged directly at the rear of an air inlet cone of the engine. The fan 15 is rotatable along the axis 3, and surrounded by a fan casing 9. In FIG. 1, it is not driven directly by the low-pressure shaft 11, but only driven indirectly by this shaft via a reducer 20, which allows it to rotate with a slower speed. Nevertheless, a solution with direct drive of the fan 15, by the low pressure shaft 11, falls within the scope of the invention.

In addition, the turbojet engine 1 defines a primary stream 16 intended to be traversed by a primary flow, as well as a secondary stream 18 intended to be traversed by a secondary flow located radially outwards with respect to the primary flow, the flow of the blower being therefore divided. As is known to those skilled in the art, the secondary stream 18 is delimited radially outwards in part by an outer shroud 23, preferably metallic, extending the fan casing 9 towards the rear. Alternatively, an aerodynamic wall forms the outer delimitation of the secondary vein 18, as will be detailed below with reference to Figure 9.

Although this has not been shown, the turbojet engine 1 incorporates a set of equipment, for example of the fuel pump type, hydraulic pump, alternator, starter, variable-pitch stator actuator (VSV), wastegate actuator, or electric power generator. These include equipment for lubricating the reducer 20. Such equipment is driven by an accessory box or AGB (not shown), which is also lubricated.

Downstream of the fan 15, in the secondary stream 18, there is provided a crown of guide vanes which are here outlet guide vanes 24 (or OGV, from the English "Outlet Guide Vane"). These stator vanes 24 connect an outer casing element, here the outer shroud 23, to an inner casing element 25 arranged externally with respect to a casing 26 of the low-pressure compressor 4. The inner casing element 25 corresponds here to the hub of the intermediate casing, and it receives the root of the blades 24. In this respect, it is noted that the outer shroud 23 forms the periphery of this intermediate casing, of which the blades 24 also form part by mechanically connecting these two elements 23, 25. Finally , it is noted that the intermediate casing hub 25 is mechanically connected to the reduction gear 20, in order to together constitute a path for the passage of forces in the direction of an engine attachment 30 carried by the outer shroud 23.

The blades 24 are spaced circumferentially from each other, and make it possible to straighten the secondary flow after it has passed through the fan 15. Moreover, as mentioned previously, these blades 24 can also fulfill a structural function. They then ensure the transfer of the forces coming from the reducer 20 and the rolling bearings 19 associated with the motor shafts and the fan hub, towards the outer shroud 23 and its motor attachment 30 (intended to connect the motor to an attachment pylon) .

Finally, the outlet guide vanes 24 ensure, in the embodiments which are described herein, a third heat exchanger function between the secondary air flow passing through the crown of vanes, and the lubricant circulating inside the these blades 24. The lubricant intended to be cooled by the outlet guide vanes 24 is that used to lubricate the rolling bearings 19, and/or the equipment of the turbojet engine, and/or the accessory box, and/or the reducer 20. These vanes 24 thus form part of the fluid circuit(s) in which the lubricant is circulated to successively lubricate the associated element(s), then to be cooled.

Referring now to Figures 2 to 8, there will be described one of the outlet guide vanes 24, according to a first preferred embodiment of the invention. It is noted that the invention as it will be described with reference to these figures can be applied to all the blades 24 of the stator crown centered on the axis 3, or else only to some of these blades.

The blade 24 can be of strictly radial orientation as in FIG. 1, or else be slightly inclined axially upstream or downstream, as shown in FIG. 2. In all cases, it is preferentially right in side view as shown in Figure 2, extending in a span direction 27.

The outlet guide vane 24 comprises an aerodynamic part 32 which corresponds to its central part, that is to say that exposed to the secondary flow circulating through the secondary stream 18. On either side of this aerodynamic part 32 used to straighten the flow leaving the fan, the blade 24 comprises respectively a foot 34 and a head 36.

The foot 34 is used to fix the vane 24 on the inner casing element, while the head 36 is used to fix this same vane on the outer shroud extending the fan casing. Although this has not been shown, the blade 24 may comprise at its root and its head platforms serving to reconstitute the secondary vein between the blades 24, in the circumferential direction. Alternatively, these platforms can be added elements between the blade roots and heads, without departing from the scope of the invention.

As will be detailed below, the blade 24 is preferably manufactured using two main bodies 32a, 32b attached fixedly one on the other, using a thermal conduction matrix 80 arranged in a space 81 delimited between these two bodies, and using two upstream and downstream parts 63, 61 respectively forming the leading edge 64 and the trailing edge 62 of the blade.

In this first preferred embodiment of the invention, the aerodynamic part 32 is equipped with two internal passages 50a, 50b substantially parallel to each other, and parallel to the span direction 27. More precisely, it is This is a first internal passage 50a for cooling the lubricant, which extends along a first main direction 52a of flow of the lubricant. This direction 52a is substantially parallel to the direction of span 27, and has a direction going from the foot 34 towards the head 36. Similarly, there is provided a second internal lubricant cooling passage 50b, which extends along a second main direction 52b of flow of the lubricant within this passage. This direction 52b is also substantially parallel to the span direction 27, and has an opposite direction going from the head 36 to the foot 34. The first passage 50a is therefore provided to be crossed radially outwards by the lubricant, while the second passage 50b is designed to be crossed radially inwards. To ensure the passage from one to the other, near the head 36, the outer radial ends of the two passages 50a, 50b are fluidically connected by a 180° elbow 54, this elbow 54 also being defined by the space 81. Alternatively, the passages 50a, 50b do not connect within the aerodynamic part 32 of the blade 24, but each extend separately over the entire length of the blade. To be fluidly connected to each other outside of the blade 24, there is for example provided a connecting elbow arranged radially outwards with respect to the blade head 36, for example resting on this head.

The internal radial ends of the two passages 50a, 50b are for their part connected to the lubricant circuit, shown diagrammatically by the element 56 in FIG. desired direction of circulation within the passages 50a, 50b, namely the introduction of the lubricant through the inner radial end of the first passage 50a, and the extraction of the lubricant through the inner radial end of the second passage 50b. Fittings 66 provide fluid communication between the internal radial ends of the passages 50a, 50b and the circuit 56, these fittings 66 crossing the foot 34. The fittings 66 crossing the foot 34 can also be defined by the space 81.

The two passages 50a, 50b as well as the elbow 54 together form the space 81 in the general shape of a U, with the first passage 50a and the second passage 50b offset from each other in a transverse direction 60 of the blade. substantially orthogonal to the span direction 27. To best optimize heat exchange, the first passage 50a is located on the side of a trailing edge 62 of the blade 24, while the second passage 50b is located on the side of a leading edge 64. However, an opposite situation can be retained, without departing from the scope of the invention. It is also noted that the invention could provide an aerodynamic part 32 only with a single internal cooling passage. In this case, some blades would be crossed by the lubricant from the inside out, while other blades would be crossed in the opposite direction.

The body 32a of the blade corresponds to an extrados body which here defines a majority, or even a very large majority of the extrados surface 72 of the aerodynamic part 32. Only the upstream end 72' and the downstream end 72'' of this extrados surface 2 are respectively formed by the upstream part 63 and the downstream part 61. This extrados body 32a also defines the part of the blade root 34 located on the side of the extrados surface, as well as the part of the blade head located on the side of this same extrados surface 72. Opposite the extrados surface 72, the body 32a delimits a recess 71 referenced in FIG. 6, this recess housing the other body 32b corresponding to an intrados body. Once the bodies 32a, 32b have been assembled, the interior surface of the body 32a which delimits the recess 71 participates in the definition of the space 81 forming the two interior passages 50a, 50b.

The intrados body 32b here defines a majority, or even a very large majority, of the intrados surface 70 of the aerodynamic part 32. Only the upstream end 70' and the downstream end 70'' of this extrados surface 70 are respectively formed by the upstream part 63 and the downstream part 61, just as transition portions 70''' are defined by the body 32a, presenting small surface areas between the parts 61, 63 and the body 32b.

The intrados body 32b has a thickness in which a U-shaped imprint is made to define the space 81, and more precisely the two interior passages 50a, 50b, as well as the elbow 54. This imprint is open on the surface opposite to the intrados surface 70, opposite surface which is intended to be pressed against the bottom of the recess 71 of the extrados body 32a. The imprint defines between the two passages 50a, 50b a solid zone 76 which is also intended to be pressed against the bottom of the recess 71, as can be seen in FIG. 3. In this figure, there is also shown a device for lubricant seal. This is a seal 73 arranged at the interface between the two bodies 32a, 32b, in order to maintain the lubricant in the internal passages 50a, 50b. This joint 73 can be supplemented by other joints at the interface between the two bodies.

The two bodies 32a, 32b are each made in one piece using a metallic material, for example by forging or casting, which are techniques for obtaining the surface condition required for the surfaces of intrados and extrados. An aluminum alloy can be used as material for making the two bodies 32a, 32b, in order to promote heat exchange with the matrix 80.

In the passages defined by these intrados and extrados bodies, the thermal conduction matrix 80 is provided, preferably U-shaped so as to fill the entire space 81. The presence of this matrix allows to improve the heat exchange performance, in particular thanks to the fact that it provides an increase in the wetted surface on the side of the lubricant which passes through the passages 50a, 50b. This matrix 80 also makes it possible to disturb the passage of the lubricant, thus generating turbulence which directly influences the convection coefficient of the lubricant passing through the matrix. The definition of such a matrix can thus be carried out in such a way as to maximize the exchange performance, while creating the least possible pressure drop between the entry and the exit of the blade.

In the first embodiment shown in Figure 3, the matrix 80 is independent of the bodies 32a, 32b, and of a nature permeable to the lubricant passing through it. It then comprises a plurality of obstacles to the circulation of the lubricant, these obstacles 82 taking the form of studs, walls, tabs, mesh, or other similar elements extending in the thickness of the passages 50a, 50b, and connected to each other. to others. As mentioned previously, this matrix could consist of simple obstacles made in one piece with the extrados body 32a and/or with the intrados body 32b.

More precisely, the obstacles 82 are interconnected by contact elements 84a resting against the lower surface body 32b, as well as by opposite contact elements 84b, resting against the upper surface body 32a. The obstacles 82 can themselves be arranged in staggered rows or in rows. For example, they are provided with a density of approximately 3 obstacles/cm². More generally, the density is for example between about 1 and 5 obstacles/cm² on average, this density being uniform or changing along the lubricant path. The matrix 80 can have a thickness of the order of several millimeters, which corresponds to the thickness of the internal passages in which it is housed.

It can be manufactured using an alloy based on aluminum or titanium, or any other material deemed to have good heat dissipation properties. This matrix 80 is preferably produced by additive manufacturing, also called 3D printing, without requiring a structural function given that the latter is conferred by the two bodies 32a, 32b. One of the following techniques can be implemented for the manufacture of the matrix 80:
- Selective laser melting (from the English “Selective Laser Melting” or “SLM”) or by electron beam (from the English “Electron Beam Melting” or “EBM”);
- selective laser sintering (from the English "Selective Laser Sintering" or "SLS") or by electron beam;
- any other type of powder solidification technique under the action of a medium to high power energy source, the principle being to melt or sinter a bed of metal powder by laser beam or electron beam.

Other more traditional techniques are also possible, such as stamping or stamping.

To facilitate the manufacture of the matrix 80, instead of being made in one piece all along the U, it can be made using several distinct matrix elements, arranged end-to-end or spaced apart. each other. For example, it can be made using three matrix elements corresponding to the two branches of the U and its base. The smaller size of these matrix elements facilitates their production by additive manufacturing.

According to an alternative embodiment shown diagrammatically in FIG. 3a, the die 80 comprises an outer sheath 84 sealed against the lubricant, and arranged in contact with the two bodies 32a, 32b. This sheath 84 has a shape substantially identical to that of the space 81 in which it is housed. The lubricant thus remains confined in the sheath 84, which makes it possible to no longer require the implementation of the sealing device 73 of the mode of FIG. 3. The obstacles 82 thus connect the opposite wall portions of the sheath 84, according to a configuration identical or similar to that of figure 3.

Returning to Figure 2, during engine operation, lubricant flowing through circuit 56 is introduced into first interior passage 50a, in first radially outward direction 52a. At this stage, the lubricant has a high temperature. A heat exchange then takes place between this lubricant marrying the matrix 80 of the first passage 50a, and the secondary flow marrying the outer surface of the intrados and extrados walls. The lubricant, after having been redirected by the elbow 54 into the second passage 50b, undergoes in the latter a similar cooling, still by heat exchange with the secondary air flow and by circulating according to the second main direction of flow 52b. Then, the cooled lubricant is extracted from the vane 24, and redirected through the closed circuit 56 to elements to be lubricated and/or to a lubricant reservoir from which cooled lubricant is pumped to lubricate elements.

One of the particularities of the invention resides in the attachment of the extrados body 32a to the intrados body 32b. Indeed, the fastening means used to mechanically connect these two bodies 32a, 32b are offset in whole or in part from the aerodynamic part 32 of the blade, in order to be located exclusively at the level of the root 34 and the head 36 of this dawn. This avoids the aerodynamic disturbances of the secondary flow, which no longer encounters these means of fixing the two bodies. In this first preferred embodiment, it is therefore all of the means for fixing the two bodies 32a, 32b to each other which are located outside the secondary vein 18.

To do this, the means in question here consist of first attachment means 90a associated with the head 36 of the blade, and second attachment means 90b associated with the root 34 of the blade. More specifically, the first attachment means 90a are arranged radially outwards with respect to the first and second blade head attachment members on the outer shroud 23. These first and second head attachment members 94a, 94b are respectively provided on the intrados body 32b and on the extrados body 32a, at a radially outer part of these bodies. Of course, the radial direction must be understood as corresponding to the span direction 27 of the blade.

The members 94a, 94b preferably take the form of fittings made in one piece with the blade, and extending substantially axially. They define orifices intended to be traversed by fixing elements of the screw or bolt type 96 as shown diagrammatically in FIG. 9, with the aim of ensuring the mechanical connection of the blade head with the outer shroud 23. Preferably, two members 94a are provided on the lower surface body 32b, and two members 94b on the upper surface body 32a, with orifices arranged substantially radially through these members.

Thus, the first fastening means 90a of the bodies 32a, 32b are arranged radially outwards with respect to these head fastening members 94a, 94b. The first means 90a comprise passage orifices 92 passing through the two bodies, as well as fixing elements of the screw or bolt type 95 passing through these orifices 92. Preferably, each body has a substantially axial row of passage orifices 92, formed in the head part of the body concerned. In other words, this row extends in the head part of the body concerned, substantially in the direction of the blade chord.

In the example shown in Figure 9, the secondary vein 18 is not delimited externally by the ferrule 23, but by a non-structural aerodynamic wall 97 arranged radially inward relative to the head fixing members 94a, 94b . Consequently, this wall 97 makes it possible to hide all of the elements 90a, 94a, 94b of the secondary flow.

Similarly, the second attachment means 90b are arranged radially inward relative to the first and second root attachment members of the blade on the intermediate casing hub 25. These first and second root attachment members 98a, 98b are respectively provided on the intrados body 32b and on the extrados body 32a, at the level of a radially internal part of these bodies.

The members 98a, 98b preferably take the form of fittings made in one piece with the blade, and extending substantially axially. They define orifices intended to be traversed by fixing elements of the screw or bolt type 96 as shown diagrammatically in FIG. 9, with the aim of ensuring the mechanical connection of the blade root with the casing hub. intermediate 25. Preferably, two members 98a are provided on the lower surface body 32b, and two members 98b on the upper surface body 32a, with orifices arranged substantially radially through these members.

Thus, the second attachment means 90b of the bodies 32a, 32b are arranged radially inward relative to these foot attachment members 98a, 98b. The second means 90b comprise passage orifices 92 passing through the two bodies, as well as fixing elements of the screw or bolt type 95 passing through these orifices 92. Preferably, each body has a substantially axial row of passage orifices 92, formed in the foot part of the concerned body.

In the example shown in Figure 9, the secondary vein 18 is not delimited internally by the intermediate casing hub 25, but by a non-structural aerodynamic wall 99 arranged radially outwards with respect to the foot attachment members 98a, 98b. Consequently, this wall 99 makes it possible to hide all of the elements 90b, 98a, 98b of the secondary flow.

Alternatively, it is noted that the first and second fixing means 90a, 90b described above can be replaced by means of the welding, brazing or even gluing type, still being located outside the aerodynamic part 32.

The example of figure 10 is similar to that of figure 9. The only differences reside in the design of the ferrule 23 and of the intermediate casing hub 25, at the level of the blades 24. Indeed, in this other example of the Figure 10, the elements 23, 25 define housings 100 in which are inserted the feet 34 and the heads 36 of the blades.

Referring now to FIG. 11, there is shown an enlarged view of an upstream part of the blade, at the level of which the upstream part 63 is attached fixedly to the upstream end 102 of the upper surface body 32a, this end 102 here also constituting the upstream end of the assembly formed by the two bodies 32a, 32b assembled.

Preferably, this fixing is carried out by gluing, continuous or in points all along the interface between the body 32a and the upstream part 63, along the spanning direction 27. As has been represented on the alternative in Figure 12, the attachment can be replaced or supplemented by attachment means 90'a, 90'b arranged outside the secondary vein, and of identical or similar design to that of the first and second attachment means 90a, 90b to which they are added. Thus these means 90'a, 90'b can comprise orifices 92 passing through the head and the foot of a downstream end 104 of the upstream part 63 and of the upstream end 102 of the extrados body 32a, these holes 92 being traversed by bolts 95 or similar elements.

In this regard, it is noted that the downstream end 104 of the upstream part 63 forms a break in thickness defining a step 106 of reduced thickness in the direction of the thickness of the blade. Similarly, the upstream end 102 of the extrados body 32a also forms a thickness break defining a step 108 of reduced thickness, superimposed on the step 106. Thus, the two steps of reduced thickness 106, 108 are pressed one against the other so as to present a progressive cumulative thickness, but continuous in the transition zone between the upstream part 63 and the extrados body 32a.

The upstream part 63, which extends in a tapered and continuous or substantially continuous manner all along the blade in the direction 27, is preferably made of a titanium alloy. This material makes it possible to confer excellent properties of mechanical resistance in view of the possible impacts of hailstones or birds, while offering the possibility of making aerodynamic surfaces efficient in the sense of roughness, undulation and shape.

Referring now to FIG. 13, there is shown an enlarged view of a downstream part of the blade, at the level of which the downstream part 61 is attached fixedly to the downstream end 110 of the upper surface body 32a, this end 110 here also constituting the downstream end of the assembly formed by the two bodies 32a, 32b.

Preferably, this fixing is also carried out by gluing, continuous or by points all along the interface between the body 32a and the downstream part 61, along the spanning direction 27. As shown in Fig. 14, the attachment can be replaced or supplemented by attachment means 90'a, 90'b arranged outside the secondary vein, and of identical or similar design to that of the first and second attachment means 90a , 90b to which they are added. Thus these means 90'a, 90'b can comprise orifices 92 passing through the head and the foot of an upstream end 112 of the downstream part 61 and of the downstream end 110 of the extrados body 32a, these holes 92 being traversed by bolts 95 or similar elements.

In this regard, it is noted that the upstream end 112 of the downstream part 61 forms a break in thickness defining a step 116 of reduced thickness in the direction of the thickness of the blade. Similarly, the downstream end 110 of the extrados body 32a also forms a break in thickness defining a step 118 of reduced thickness, superimposed on the step 116. Thus, the two steps of reduced thickness 116, 118 are pressed one against the other so as to present a progressive cumulative thickness, but continuous in the transition zone between the downstream part 61 and the extrados body 32a.

The downstream part 61, which extends in a tapered and continuous or substantially continuous manner all along the blade in the direction 27, is also preferably made of a titanium alloy, so as to make the aerodynamic surfaces efficient in the sense of roughness, waviness and shape.

According to a second preferred embodiment of the invention, represented in FIGS. 15 to 17, one of the particularities resides in the shape of the upstream and downstream parts 63, 61, whose section in the general shape of a U or V s observed all along the span direction 27. In the following, reference will be made to a V, but a general U-shape remains possible, without departing from the scope of the invention.

The tip of the V forms the upstream end of the leading edge 64 for the upstream part 63, while the tip of the V forms the downstream end of the trailing edge 62 for the downstream part 61.

For the upstream part 63, one of the branches of the V forms the upstream end 72' of the extrados surface 72, while the other branch of the V forms the upstream end 70' of the intrados surface 70 Similarly, for the upstream part 63, one of the branches of the V forms the downstream end 72" of the extrados surface 72, while the other branch of the V forms the downstream end 70". of the intrados surface 70.

Thanks to this V-shape of the upstream and downstream parts 63, 61, these each define internally a hollow 120 between the branches, for receiving and housing a respective axial end of the thermal conduction matrix 80. A kind fitting can be made for the axial ends of the matrix 80, in the recesses 120 of the parts 63, 61, so as to reinforce the overall mechanical strength of the blade.

Unlike the first preferred embodiment, this second mode provides for each part 63, 61 to be fixed to each of the two extrados 32a and intrados 32b bodies.

Thus, one of the branches of the V of the upstream part 63 has a free end which forms a break in thickness, defining a step 106' of reduced thickness in the direction of the thickness of the blade. Similarly, the upstream end 102 of the extrados body 32a also forms a break in thickness defining a step 108' of reduced thickness, superimposed on the step 106'. Thus, the two steps of reduced thickness 106', 108' are pressed against each other so as to present a progressive cumulative thickness, but continuous in the transition zone between the upstream part 63 and the extrados body 32a. Preferably, there is provided a fixing by gluing, continuous or by points, all along the interface between the body 32a and the upstream part 63, along the spanning direction 27.

In addition, the other branch of the V of the upstream part 63 has a free end which also forms a break in thickness, also defining a step 106' of reduced thickness in the direction of the thickness of the blade. Similarly, the upstream end 102' of the lower surface body 32b also forms a thickness break defining a step 108' of reduced thickness, superimposed on the step 106'. Thus, the two steps of reduced thickness 106', 108' are also pressed one against the other so as to present a progressive cumulative thickness, but continuous in the transition zone between the upstream part 63 and the body of intrados 32b. Preferably, there is provided a fixing by gluing, continuous or by points, all along the interface between the body 32b and the upstream part 63, along the span direction 27.

On the other hand, one of the branches of the V of the downstream part 61 has a free end which forms a break in thickness, defining a step 116' of reduced thickness in the direction of the thickness of the blade. Similarly, the downstream end 110 of the extrados body 32a also forms a thickness break defining a step 118' of reduced thickness, superimposed on the step 116'. Thus, the two steps of reduced thickness 116', 118' are pressed against each other so as to present a progressive cumulative thickness, but continuous in the transition zone between the downstream part 61 and the extrados body 32a. Preferably, there is provided a fixing by gluing, continuous or by points, all along the interface between the body 32a and the downstream part 61, along the span direction 27.

In addition, the other branch of the V of the downstream part 61 has a free end which forms a break in thickness, also defining a step 116' of reduced thickness in the direction of the thickness of the blade. Similarly, the downstream end 110' of the lower surface body 32b also forms a thickness break defining a step 118' of reduced thickness, superimposed on the step 116'. Thus, the two steps of reduced thickness 116', 118' are pressed against each other so as to present a progressive cumulative thickness, but continuous in the transition zone between the downstream part 61 and the intrados body 32b. Preferably, there is provided a fixing by gluing, continuous or by points, all along the interface between the body 32b and the downstream part 61, along the spanning direction 27.

By connecting the two extrados and intrados bodies 32a, 32b, the upstream 63 and downstream 61 parts also participate in fixing these bodies 32a, 32b to each other.

In this second preferred embodiment of the invention, the steps 106', 116' of the parts 63, 61 are oriented towards the outside of the blade, while the corresponding steps 108', 118' of the bodies 32a, 32b are oriented towards the inside of the blade. Nevertheless, an inverted design can be envisaged, in which the steps 106', 116' of the parts 63, 61 are oriented towards the inside of the blade, as shown in the alternative of figure 18.

Figure 19 shows that the fixing of the upstream and downstream parts 63, 61, on the extrados and intrados bodies 32a, 32b, can be replaced or supplemented by fixing means 90'a, 90'b arranged outside of the secondary vein, and of identical or similar design to that of the first and second fixing means 90a, 90b to which they are added, or with which they can be confused when these means participate simultaneously in the fixing of two bodies 32a, 32b l on top of each other. Thus these means 90'a, 90'b can comprise orifices 92 passing through the head and the foot of the upstream end 102 of the upper surface body 32a, of the upstream end 102' of the lower surface body 32b, and the two branches of the V of the upstream part 63, these orifices 92 being crossed by bolts 95 or similar elements also offset from the secondary stream.

A similar configuration (not shown) can be adopted for the downstream part 61, and it is further specified that these additional/alternative fixing means 90'a, 90'b are equally applicable to the second embodiment of Figures 15 to 17 , than to its alternative of figures 18 and 19.

In view of the foregoing, the blade 24 can be manufactured simply by separately producing each of its five constituent parts, namely the two bodies 32a, 32b, the matrix 80 and the two upstream and downstream parts 63, 61, then by assembling them to each other so that the matrix 80 is located in the space 81 between the two bodies 32a, 32b, before fixing these using the bolts 95. For example, the two upstream and downstream parts 63, 61 can be fixed on the bodies 32a, 32b, after the assembly of these one on the other. This solution makes it possible to confer better interchangeability of the upstream part 63 and of the downstream part 61, in the event of degradation. Alternatively, the upstream and downstream parts 63, 61 can first be assembled to the thermal conduction matrix 80, before the extrados and intrados bodies 32a, 32b are attached.

Of course, various modifications can be made by those skilled in the art to the invention which has just been described, solely by way of non-limiting examples and the scope of which is delimited by the appended claims. In particular, it is noted that in the case not shown of the inlet guide vanes for straightening the airflow upstream of the fan, these vanes are arranged throughout the airflow of the fan around a cone non-rotating air inlet, the roots of the blades then being connected to this fixed air inlet cone.

Furthermore, other engine architectures also fall within the scope of the invention, responding to the designation “dual-flow aircraft turbomachine”. It may be for example a triple body architecture (namely comprising three shafts respectively connecting first turbine stages to a fan, second turbine stages to low pressure compressor stages, and third turbine stages to high pressure compressor stages).

Claims (10)

Guide vane (24) intended to be arranged in all or part of an air flow of a fan (15) of a dual-flow aircraft turbomachine, the guide vane comprising an aerodynamic part (32) for straightening flow intended to be embraced by said all or part of the fan air flow, said blade being produced using:
- an intrados body (32b) defining at least a part of an intrados surface (70) of the aerodynamic part (32), the intrados body comprising at least a first head attachment member ( 94a) intended for fixing the blade to an outer casing element (23), as well as at least one first root fixing member (98a) intended for fixing the vane to an inner casing element ( 25);
- an extrados body (32a) defining at least a part of an extrados surface (72) of the aerodynamic part (32), the extrados body comprising at least one second head attachment member ( 94b) intended for fixing the blade to the outer casing element (23), as well as at least one second root fixing member (98b) intended for fixing the vane to the inner housing (25);
- a thermal conduction matrix (80) arranged in a space (81) delimited between the intrados and extrados bodies (32b, 32a), said matrix being intended to be traversed by lubricant and integrating obstacles ( 82) to the circulation of lubricant; And
- means (90a, 90b) for fixing the intrados body (32b) to the extrados body (32a), said means for fixing the intrados body to the extrados body comprising first fixing means ( 90a) arranged radially outward relative to the first and second head attachment members (94a, 94b), and second attachment means (90b) arranged radially inward relative to the first and second foot (98a, 98b),
characterized in that the blade is also produced using an upstream part (63) forming a leading edge (64) of the blade, attached fixedly to at least one of the lower surfaces and upper surface (32b, 32a), and a downstream part (61) forming a trailing edge (62) of the blade, attached fixedly to at least one of the lower and upper surfaces (32b , 32a). Blade according to Claim 1, characterized in that the upstream part (63) and the downstream part (61) are each made of a material different from that of the material(s) constituting the intrados and extrados bodies (32b, 32a ), and preferably each made of titanium or a titanium alloy. Blade according to Claim 1 or Claim 2, characterized in that the upstream part (63) and the downstream part (61) are each bonded to at least one of the intrados and extrados bodies (32b, 32a) , and/or fixed to at least one of the intrados and extrados bodies using said first and second fixing means (90a, 90b), preferably by being traversed by these means. Blade according to any one of the preceding claims, characterized in that the upstream part (63) has a downstream end (104) forming a break in thickness defining a step (106), the upstream part extending in a direction wingspan (27) of the blade and being superimposed on an upstream end (102) of the assembly formed by the intrados and extrados bodies (32b, 32a), and/or in that the downstream part ( 61) has an upstream end (112) forming a break in thickness defining a step (116), the downstream part extending along the span direction (27) of the blade and being superimposed on a downstream end (110 ) of the assembly formed by the intrados and extrados bodies (32b, 32a). Blade according to any one of Claims 1 to 3, characterized in that the upstream part (63) has the general shape of a U or a V, of which one of the branches of the U/V forms an upstream end (70') of the intrados surface (70) of the blade, and whose other branch of the U/V forms an upstream end (72') of the extrados surface (72) of the blade, and/or in that the downstream part (61) has a general U or V shape, one of the branches of the U/V of which forms a downstream end (70'') of the lower surface (70) of the blade , and whose other branch of the U/V forms a downstream end (72'') of the extrados surface (72) of the blade. Blade according to Claim 5, characterized in that each branch of U/V has a free end with a break in thickness defining a step (106', 116') of reduced thickness, the step being oriented towards the inside of dawn, or outward from dawn. Blade according to Claim 5 or Claim 6, characterized in that the hollow (120) defined internally by each U/V houses one end of the thermal conduction matrix (80). Guide vane according to any one of the preceding claims, characterized in that the said first fixing means (90a) and the said second fixing means (90b) comprise bolts (95) passing through passage orifices (92) made through the intrados and extrados bodies (32b, 32a). Aircraft turbomachine (1), preferably a turbojet engine, comprising a plurality of guide vanes (24) according to any one of the preceding claims, arranged downstream or upstream of a fan (15) of the turbomachine, and in that the first and second fixing means (90a, 90b) are arranged outside of said all or part of the fan air flow (15), preferably delimited by at least one aerodynamic wall (97, 99) arranged between outer and inner housing members (23, 25). Method of manufacturing a blade (24) according to any one of Claims 1 to 8, characterized in that it comprises the following steps:
- production of the intrados and extrados bodies (32b, 32a) and of said thermal conduction matrix (80), as well as upstream and downstream parts (63, 61) respectively forming the leading edge (64) and the trailing edge (62);
- fixing of the intrados body (32b) on the extrados body (32a), using the first and second fixing means (90a, 90b), and fixing of the upstream and downstream parts (63, 61) on the intrados/extrados bodies (32b, 32a).