Rectifier intermediate housing with arm made of monoblock structure

Description

Domaine de l'invention

[0001] The invention relates to the general field of twin-flow turbomachinery for aircraft. It relates in particular to a fixed turbomachine casing comprising an annular row of fixed blades and an annular row of structural arms. Arrière-plan technique

[0002] Prior art includes documents SE-C2-528183C2, US-B2-10458247 and EP-A1-3450685.

[0003] A turbofan engine, particularly one for aircraft, extending along a longitudinal axis, comprises a movable fan arranged upstream of at least one compressor, following the direction of gas flow within the turbofan. The airflow passing through the shrouded fan is divided into a primary flow circulating in a primary channel where the compressor is housed, at least partially, and a secondary flow circulating in a secondary channel around the compressor. These primary and secondary channels are separated by an annular inter-channel housing which carries an annular separating nozzle.

[0004] The primary flow is formed, at least in part, by an inlet casing located upstream of the compressor and carrying the separation nozzle, a low-pressure compressor casing, a high-pressure compressor casing, and an intermediate casing located downstream of the low-pressure compressor casing and upstream of the high-pressure compressor casing. The inlet and intermediate casings are structural components that transmit forces. The intermediate casing includes structural arms that extend radially across the primary flow and are configured to allow the passage of auxiliary components. The inlet casing also includes an annular row of fixed vanes known by the acronym IGV (Inlet Guide Vane).

[0005] The compressor typically comprises one or more stages, each consisting of an annular row of stator blades mounted upstream of an annular row of moving blades. Typically, there can be up to five annular rows of stator blades. Each annular row of stator (or blades) is supported by the compressor housing, and each annular row of moving blades is mounted on a disc or drum centered on the longitudinal axis of the turbomachine. The fifth stage is generally located upstream of a portion of the turbomachine hub that has a gooseneck shape.

[0006] The structural casings carrying structural arms and the low-pressure compressor with its many stages lengthen the turbomachine along the longitudinal axis and consequently negatively impact the mass of the turbomachine. Résumé de l'invention

[0007] The objective of the present invention is to provide a solution for reducing the size of the turbomachine while maintaining the performance of the turbomachine.

[0008] We achieve this objective in accordance with the invention by means of an annular intermediate housing for a turbomachine with longitudinal axis X, particularly for an aircraft, in which an aerodynamic airflow is intended to circulate, at least in part, the intermediate housing comprising: an annular radially internal ferrule, an annular radially external ferrule, at least one stator blade extending substantially along a radial axis Z, the stator blade comprising a blade with a leading edge and a trailing edge, and at least one aerodynamic component which is formed of a structural arm extending radially at least in part between the radially internal ferrule and the radially external ferrule, the stator blade extending between a first platform and a second platform and the aerodynamic element comprising a leading edge which is aligned with the leading edge of the stator blade in a plane perpendicular to the longitudinal axis X, the leading edge of the aerodynamic element being supported by a profiled portion arranged upstream of the structural arm along the direction of the aerodynamic airflow, the profiled portion and the structural arm being monobloc, and the aerodynamic element being monobloc with the radially internal ferrule and the radially external ferrule, the intermediate casing comprising at least two aerodynamic elements spaced along the circumferential direction around the longitudinal axis and a straightening assembly which is reported between the two aerodynamic elements and which is distinct from the two aerodynamic elements, the straightening assembly comprising the first platform,the second platform and a plurality of stator blades extending radially between the first and second platforms and being regularly distributed along the circumferential direction, each leading edge of the plurality of stator blades is aligned with the leading edge of the aerodynamic element in the plane perpendicular to the longitudinal axis.

[0009] Thus, this solution achieves the aforementioned objective. In particular, it allows for a reduction in the size of the turbomachine, especially its length along the longitudinal axis. This axial reduction can reach at least 30 mm, which is significant in a turbomachine and relative to its mass. Furthermore, manufacturing the aerodynamic component as a single unit, both with itself and with the intermediate casing's ferrules, contributes to the turbomachine's mass reduction and the assembly and disassembly time. The fan is also offset by at least 30 mm in the case of a turbofan. In addition, the assembly and disassembly of such an intermediate casing are facilitated.

[0010] The housing also includes one or more of the following features, taken alone or in combination: The profiled portion extends radially between a radially internal platform and a radially external platform, the radially internal and radially external platforms being respectively integral with the radially internal and radially external ferrules, and in that the radially internal platform has a radially internal surface bearing a first layer of abradable material. The first and second platforms are attached and fixed respectively to the radially internal and radially external ferrules, the first platform having a radially internal surface bearing a second layer of abradable material, the second layer of abradable material being aligned in the circumferential direction with the first layer of abradable material.The first platform comprises a base that is fixed to an annular bearing surface of the radially internal ferrule with at least one fastening element providing axial fixation. The second platform is fixed to a radial wall of the radially external ferrule that extends radially outwards from a radially external surface and via at least one fastening element. The second platform has legs that each extend from its radially external surface, each leg being fixed to an axial leg of the radial wall with fastening elements providing radial fixation.The second platform comprises a radial mounting flange extending radially outwards from its outer radial surface and in the circumferential direction around its entire periphery. The radial mounting flange is fixed to a lower branch of the radial wall extending along the radial axis, with the fastening elements providing axial fixation. The straightening assembly is a single piece. The leading edge of the aerodynamic element is located at an axial distance from an intersection zone between the airfoil portion and the structural arm, and the intersection zone has a circumferential thickness substantially equal to three times the frontal area of ​​the airfoil portion.The stator blade has an axial chord measured between the leading edge and the trailing edge, and the profiled portion has an axial length measured between the leading edge of the aerodynamic element and the intersection zone substantially equal to the axial chord. The radial axis is perpendicular to the longitudinal axis. The intermediate housing is produced by casting or additive manufacturing. The radial wall of the intermediate housing has a T-shape with a lower branch, an upper branch, and an axial leg. The radially inner and radially outer shells are concentric. The intermediate housing comprises six aerodynamic elements. The intermediate housing is arranged axially downstream of a turbomachine compressor housing, in particular a low-pressure compressor housing.The compressor comprises a compressor housing and compressor blades extending substantially radially within the compressor housing, through a primary flow, and from a drum centered on the longitudinal axis. The compressor housing is made of a composite material, while the compressor blades and drum are made of a metallic material. The moving compressor blades are welded to the drum centered on the longitudinal axis. The intermediate housing is an inter-compressor housing.

[0011] According to an aspect not part of the invention, an annular intermediate housing for a turbomachine with longitudinal axis X, particularly for an aircraft, in which an aerodynamic airflow is intended to circulate at least partially, comprises: an annular radially internal ferrule, an annular radially external ferrule, at least one stator blade extending substantially along a radial axis Z between a first platform and a second platform, the stator blade comprising a blade with a leading edge and a trailing edge, and at least one aerodynamic component which is formed of a structural arm extending radially at least in part between the radially internal ferrule and the radially external ferrule, the aerodynamic element comprising a leading edge which is aligned with the leading edge of the stator blade in a plane perpendicular to the longitudinal axis X, the leading edge of the aerodynamic element being supported by a profiled portion arranged upstream of the structural arm along the direction of the aerodynamic airflow, the profiled portion and the structural arm being monobloc, and the aerodynamic element being monobloc with the radially internal ferrule and the radially external ferrule, and in that the housing comprises at least two aerodynamic elements spaced along the circumferential direction around the longitudinal axis X and a straightening assembly which is reported between the two aerodynamic elements, the straightening assembly comprising the first platform, the second platform and a plurality of stator blades extending radially between the first and second platforms and being regularly distributed along the circumferential direction,Each leading edge of the plurality of stator blades is aligned with the leading edge of the aerodynamic element in the plane perpendicular to the longitudinal axis X.

[0012] This solution allows for a reduction in the size of the turbomachine, particularly its length along the longitudinal axis, with an axial gain of at least 30 mm, which is significant in a turbomachine and relative to its mass. The construction of the aerodynamic component as a single unit, both itself and with the intermediate casing's ferrules, further reduces the turbomachine's mass and the assembly and disassembly time. The fan is also offset by at least 30 mm in the case of a turbofan. In addition, the assembly and disassembly of such an intermediate casing are simplified.Finally, placing the assembly including the stator blades between the aerodynamic components makes it easier to maintain the intermediate casing and reduces costs by only mounting and dismounting the rectifier assembly and not the entire intermediate casing.

[0013] The invention further relates to an annular intermediate housing for a turbomachine with a longitudinal axis X, particularly for an aircraft, in which an aerodynamic airflow is intended to circulate, at least partially, the intermediate housing comprising: an annular radially internal ferrule, an annular radially external ferrule, at least one stator blade extending substantially along a radial axis Z between a first platform and a second platform, the stator blade comprising a blade with a leading edge and a trailing edge, and at least one aerodynamic component which is formed of a structural arm extending radially at least in part between the radially internal ferrule and the radially external ferrule, the stator blade extends between a first platform and a second platform and the aerodynamic element comprising a leading edge which is aligned with the leading edge of the stator blade in a plane perpendicular to the longitudinal axis X, the leading edge of the aerodynamic element being supported by a profiled portion arranged upstream of the structural arm along the direction of the aerodynamic airflow, the profiled portion and the structural arm being monobloc, and the aerodynamic element being monobloc with the radially internal ferrule and the radially external ferrule, and in that the first platform is monobloc with the radially internal ferrule and the second platform is monobloc with the radially external ferrule, the first and second platforms each respectively comprising a plurality of slots of complementary shape with the blades of the stator blades which are distributed regularly around the longitudinal axis X,each stator blade comprising a radially internal end which is received in a corresponding first slot of the first platform and a radially external end which is received in a corresponding second slot of the second platform.

[0014] This solution allows for a reduction in the size of the turbomachine, particularly its length along the longitudinal axis, with an axial gain of at least 30 mm, which is significant in a turbomachine and relative to its mass. The construction of the aerodynamic component as a single unit, both itself and with the intermediate casing's ferrules, further reduces the turbomachine's mass and the assembly and disassembly time. The fan is also offset by at least 30 mm in the case of a turbofan. In addition, the assembly and disassembly of such an intermediate casing are simplified.Finally, the fact that the stator blades are attached to the first and second platforms, which are integral with the casing ferrules, makes it easier to maintain the intermediate casing by intervening and / or replacing only one or more stator blades at a time, since they are all attached.

[0015] According to a feature of this intermediate housing, each of the radially external or internal ends is integral with a stop platform resting radially outside a first or second platform, and the other of each of the radially internal or external ends opposite radially is blocked or fixed on the first or second platform.

[0016] According to another characteristic of this intermediate housing, the locking or fixing is achieved by a locking device or a weld.

[0017] According to another aspect not part of the invention, a turbomachine module with longitudinal axis X in which an aerodynamic flow circulates, comprises at least one compressor surrounded by a compressor housing which is mounted on the intermediate turbomachine housing as above, the compressor housing comprising a bottom wall fixed on the radial wall of the intermediate housing.

[0018] The invention further relates to a longitudinal axis X-shaped, dual-flow turbomachine, particularly for aircraft, comprising: at least one blower generating an airflow and comprising at least one annular row of blower blades carried by a hub with longitudinal axis X, a separation nozzle, downstream of the row of blower blades separating the airflow into a primary flow circulating in an annular primary channel and a secondary flow circulating in an annular secondary channel, at least one compressor arranged downstream of an inlet of the primary channel formed by an annular edge of the separation nozzle and comprising annular rows of moving blades and straightening blades, and at least one intermediate turbomachine casing having any of the preceding characteristics, the intermediate casing comprising a plurality of stator blades distributed around the longitudinal axis X so as to straighten the airflow at the outlet of the last row of moving blades of the compressor. Brève description des figures

[0019] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent upon reading the detailed explanatory description that follows, of embodiments of the invention given by way of purely illustrative and non-limiting examples, with reference to the accompanying schematic drawings in which: [ Fig. 1 ] There figure 1 is an axial cross-sectional view of an example of a turbomachine to which the invention applies; [ Fig. 2 ] There figure 2 is a partial axial cross-sectional view of the front of a turbomachine with a separation nozzle partially delimiting a primary and a secondary flow according to the invention; Fig. 3 ] There figure 3 is a perspective and substantially front view of an intermediate turbomachine rectifier housing according to the invention; [ Fig. 4 ] There figure 4 is a perspective and substantially front view of an example of an intermediate rectifier housing with aerodynamic components and which is intended to receive a set of stator blades fitted according to the invention; Fig. 5 ] There figure 5 schematically illustrates in cross-section an aerodynamic component formed of a profiled portion and a structural arm downstream of the profiled portion and an adjacent stator blade in a circumferential direction, the aerodynamic component and the stator blade extending transversely in a primary flow of the turbomachine according to the invention; Fig. 6 ] There figure 6 is a perspective and detail view of an example of the upper attachment of a set of stator blades to the intermediate housing according to the invention; [ Fig. 7 ] There figure 7 represents a perspective and detail view of an example of the lower attachment of a set of stator blades to the intermediate housing according to the invention; Fig. 8 ] There figure 8 illustrates in perspective and front view another embodiment of an intermediate straightening housing receiving a straightening assembly attached between two aerodynamic components according to the invention; [ Fig. 9 ] There figure 9 is an axial cross-sectional view of the intermediate crankcase of the figure 8 according to the invention; [ Fig. 10 ] There figure 10 represents another embodiment of a rectifier assembly intended to be mounted on an intermediate turbomachine casing and which includes stator blades also mounted according to the invention; Fig. 11 ] There figure 11 is a bottom view of an embodiment of radially internal locking of the ends of the stator blades on an intermediate housing platform of a turbomachine according to the invention; Fig. 12 ] There figure 12 illustrates an embodiment of mounting stator blades on platforms of an intermediate turbomachine rectifier housing according to the invention; [ Fig. 13 ] There figure 13 represents another embodiment of the arrangement of stator blades on an intermediate turbomachine rectifier housing according to the invention; and [ Fig. 14 ] There figure 14 is an axial cross-sectional view of the intermediate crankcase according to the figure 13 . Description détaillée de l'invention

[0020] There figure 1 The figure shows an axial cross-sectional view of a turbomachine with longitudinal axis X to which the invention applies. The turbomachine shown is a twin-spool, twin-flow turbomachine intended for mounting on an aircraft, such as an airplane. Of course, the invention is not limited to this type of turbomachine.

[0021] In the present invention, and generally, the terms "upstream" and "downstream" are defined with respect to the circulation of gases or airflows in the turbomachine and here along the longitudinal axis X (and even from left to right on the figure 1 The terms "axial" and "axially" are defined with respect to the longitudinal axis X. The terms "external", "outside", "internal", "internal", and "radial" are defined with respect to a radial axis Z that extends from the longitudinal axis X and with respect to the distance from the longitudinal axis X. The radial axis is perpendicular to the longitudinal axis.

[0022] This double-flow turbomachine 1 generally includes a blower 2 mounted upstream of a gas generator 3 or engine (gas turbine).

[0023] The gas generator 3 comprises, from upstream to downstream, a low-pressure compressor 4, a high-pressure compressor 5, a combustion chamber 6, a high-pressure turbine 7, and a low-pressure turbine 8. Typically, the turbomachine includes a low-pressure shaft 9 that connects the low-pressure compressor 4 and the low-pressure turbine 8 to form a low-pressure unit, and a high-pressure shaft 10 that connects the high-pressure compressor 5 and the high-pressure turbine 7 to form a high-pressure unit. The low-pressure shaft 9, centered on the longitudinal axis X, is intended to drive a fan shaft 2a. A power transmission mechanism 11, such as a speed reducer, may be interposed between the pressure shaft and the fan shaft 2a. The fan comprises fan blades 2b supported by a hub with longitudinal axis X.

[0024] The blower 2 is surrounded by a blower casing 12 carried by a nacelle 13 and compresses the airflow which enters the turbomachine 1 and which is divided into a primary airflow passing through the gas generator and in particular in a primary channel 14, and into a secondary airflow circulating around the gas generator 3 in a secondary channel 15.

[0025] The primary and secondary flows are separated by an annular inter-flow casing 16, which carries a separating nozzle 17. The secondary flow 15 extends radially outside the primary flow 14 and is coaxial with it. The secondary airflow is ejected by a secondary nozzle 18 terminating the nacelle 13, while the primary airflow is ejected outside the turbomachine via an ejection nozzle 19 located downstream of the gas generator 3.

[0026] On the figure 2 The secondary channel 15 is delimited, at least in part, along its longitudinal axis by a compressor housing 21 and an intermediate rectifier housing 22. As previously mentioned, these housings 21 and 22 have a structural role, as they allow the transmission of forces. In this example, the intermediate housing 22 is positioned between the low-pressure compressor 4 and the high-pressure compressor 5. The intermediate housing 22 is referred to as the inter-compressor housing. The compressor housing 21 partially supports the separation nozzle 17.

[0027] The compressor casing 21 surrounds the low-pressure compressor 4 and comprises an inner shell 23 and an outer shell 24, concentric along the longitudinal axis. The low-pressure compressor 4, like the high-pressure compressor 5 (and the turbines), comprises several stages of blades, each with an annular row of stator blades mounted upstream of an annular row of rotor blades. On this figure 2 Four annular rows of straightening blades 4b are shown, alternating with four annular rows of movable blades 4a. Each row of straightening blades comprises a plurality of straightening or fixed blades distributed circumferentially around the longitudinal axis X. Each straightening blade comprises a blade extending substantially radially between an inner annular wall and an outer annular wall (not shown). The outer annular wall is advantageously supported by two angular half-shells centered on the longitudinal axis.

[0028] In this example, each row of moving blades 4a of the compressor comprises a plurality of moving blades that are equally distributed circumferentially around a drum (not shown) centered on the longitudinal axis X and radially from this drum. The drum is arranged in a hub 30 through which the low-pressure shaft 9 passes. The moving blades are welded to the drum. The stator blades deflect and straighten the aerodynamic flow exiting each moving blade located upstream of them.

[0029] The compressor housing halves are made of a composite material. The moving blades and the rectifier blades are made of a metallic material.

[0030] With reference to figures 3 et 4 The intermediate straightening housing 22 is annular and centered on the longitudinal axis X. The intermediate housing 22 is located at the "gooseneck" of the hub 30 (illustrated on the figure 1 of the turbomachine. The intermediate housing 22 comprises an annular radially internal ferrule 31 and an annular radially external ferrule 32, both centered on the longitudinal axis. The internal and external radial ferrules are concentric. In this example, the intermediate housing 22 is a single piece with the internal and external radial ferrules 31 and 32 (i.e., the ferrules 31 and 32 are machined from the same material). Advantageously, in this case, the intermediate housing 22 is manufactured by additive manufacturing.

[0031] In another embodiment not shown, the intermediate housing 22 is formed of several sectors of angular one-piece housings which are arranged adjacently in a circumferential direction around the longitudinal axis X and which are fixed together to form a ring.

[0032] The intermediate housing 22 also includes at least one aerodynamic element 33 that extends radially between the radially internal 31 and external 32 ferrules. At least one stator blade 34 is arranged adjacent to the aerodynamic element 33 in the circumferential direction around the longitudinal axis X. In particular, several stator blades 34 are arranged regularly around the longitudinal axis X and between two aerodynamic elements 33.

[0033] The stator blades 34 are also rectifier blades. In the following description, the term "stator blade" is used for the intermediate housing 22, and the term "rectifier blade" is used for the compressor. Here, the last row of rectifier blades of the compressor is integrated into the intermediate housing 22 in such a way as to perform a rectification function on said intermediate housing and to obtain axial gain. In other words, all the stator blades are integrated into an inter-arm space along the circumferential direction. The last annular row of rectifier blades of the compressor belongs to the intermediate housing 22, which is fixed. And this intermediate housing, as configured, rectifies the airflow exiting the last row of moving blades 4a of the low-pressure compressor, here upstream.

[0034] On the figure 5 In particular, the aerodynamic component 33 is formed of a structural arm 35 and a profiled portion 36 arranged upstream of the structural arm 35. The profiled portion 36 has the profile of a stator blade (or stator blade) which is, so to speak, integrated into the structural arm. The profiled portion 36 straightens the aerodynamic flow exiting the low-pressure compressor 4, while the structural arm 35 structurally connects the radially internal ferrule 31 and the external ferrule 32. The structural arm also supports the hub 30 and the inter-flow casing 16 of the turbomachine and transmits the turbomachine's forces.

[0035] Each stator blade 34 comprises a blade 37 which extends substantially radially between a radially internal end 38 and a radially external end 39 (cf. figure 3 The stacking axis of the stator blades (between the radially inner and outer ends 38, 39) may be at an angle to the radial axis Z (the stacking axis is not perfectly parallel to the radial axis Z). The blade 37 comprises an intrados surface 40 and an extrados surface 41, which are connected upstream by a leading edge 42 and downstream by a trailing edge 43. The intrados and extrados surfaces 40, 41 are opposite along a transverse axis T (perpendicular to the longitudinal axis or along the circumferential direction). The cross-section of the blade has a curved profile. Each blade 37 of the stator blade 34 has an axial chord Cx, which is measured between the leading edge 42 and the trailing edge 43 substantially along the longitudinal axis.

[0036] The streamlined portion 36 and the structural arm 35 are advantageously one-piece in order to optimize the mass reduction of the turbomachine and assembly operations. For the same purpose, the aerodynamic element 33 is one-piece with the intermediate casing 22, i.e. with the radially internal and external ferrules 31, 32. The primary flow circulates between the two ferrules 31, 32 and also between the aerodynamic elements 33 (structural arms and streamlined portion).

[0037] The aerodynamic element 33 extends substantially axially between a leading edge 51 and a distal edge 56. The leading edge 51 and the distal edge 56 are connected by an intrados surface 53 and an extrados surface 54. There is surface continuity between the intrados faces of the streamlined portion and the structural arm (which form the intrados surface 53) and between the extrados faces of the streamlined portion and the structural arm (which form the extrados surface 54). The leading edge 51 of the aerodynamic element 33 is aligned with the leading edge 42 of the adjacent stator blades 34 in a plane P perpendicular to the longitudinal axis X.

[0038] Still on the figure 5 The streamlined portion 36 includes an upstream edge that is formed or supported by the leading edge of the aerodynamic element. The upstream edge of the streamlined portion 36 is located at a predetermined axial distance Dx (delimited by a point XA) from an intersection zone (delimited by a point XB) between the streamlined portion and the structural arm. This axial distance Dx corresponds to the axial length of the streamlined portion 36. The axial length is substantially equal to the axial chord length Cx of a stator blade 34. The intersection zone has a thickness e1 in the circumferential direction that is substantially equal to three times the maximum cross-section of the streamlined portion 36 (which also corresponds to the maximum cross-section of a stator blade 34). The thickness e1 is measured between the lower surface 53 and the upper surface 54 of the aerodynamic element 33.The tangent TB which passes through point XB at the level of the intrados surface of the structural arm has a predetermined angle α (alpha) with respect to the longitudinal axis X and which is between 5° and 10°.

[0039] With reference to the figure 3 The profiled portion 36 extends radially between a radially internal end 44 and a radially external end 45. Similarly, the structural arm 35 extends radially between a radially internal end 48 and a radially external end 49. The profiled portion 36 and the structural arm 35 have, of course, the same radial height.

[0040] Advantageously, the stator blades 34 and the aerodynamic components 33 are solid.

[0041] As we can see on the figure 4 , a radially internal platform 46 extends axially from a circular radially internal edge 87 of the radially internal ferrule 31. In particular, the platform 47 extends upstream from the radially internal edge as illustrated in the figure 3 This radially internal platform 46 comprises two opposing circumferential sides 59 along the circumferential direction and an upstream rim 60 that is axially offset from the radially internal edge 87. Advantageously, the upstream rim 60 extends in a direction parallel to the radially internal edge 87. The radially internal platform 46 further comprises a radially internal surface 79 that carries a first layer 80 of abradable material. The abradable material decomposes easily and is friable upon contact with the rotor (last row of moving blades of the low-pressure compressor) while still providing a seal with it. The abradable material comprises a metallic or non-metallic material. This first layer 80 extends along the circumferential direction and over the entire transverse width of the radially internal platform.

[0042] A radially external platform 47 also extends axially from a radially external edge 78 of the radially external ferrule 32. Similarly, the platform 47 extends upstream from the radially external edge as illustrated in the figure 3 The radially external platform 47 comprises two opposing circumferential flanks 61 which are connected by an upstream rim 62. The latter is parallel to the radially external edge 78.

[0043] The radially internal and external platforms 46, 47 are integral with the radially internal and external ferrules 31, 32. The radially internal end 44 of the profiled portion 36 is integral with the radially internal platform 46, and the radially external end 45 of the profiled portion 36 is integral with the radially external platform 47. In other words, the profiled portion 36 extends radially between the radially internal and radially external platforms. A portion of the radially internal and external ends of the structural arm 35 is respectively integral with the radially internal and external platforms, as illustrated in the figure. figure 4 .

[0044] In particular, and with reference to the figure 3 The radially internal end 44 is integral with the radially internal ferrule 31 and the radially external end 45 is integral with the radially external ferrule 32. The structural arm 35 also includes a radially internal end 48 which is integral with the radially internal platform 46 and a radially external end 49 which is integral with the radially external platform 47.

[0045] The stator blades 34 between the aerodynamic elements 33 are attached to the intermediate housing 22. By the term "attached" in this description, we mean a part separate (here the stator blades) from the intermediate housing and which is not made using the same manufacturing process as the intermediate housing. In this case, the stator blades are made separately from the rest of the intermediate housing components. They are then attached and fixed to the intermediate housing. For this purpose, the radially internal ends 38 of each stator blade 34 are integral with a first platform 95, which extends over an angular portion in a circumferential direction (cf. figures 3 , 11 ). Similarly, the radially external end 39 of each stator blade is integral with a second platform 96, which extends over an angular portion along the circumferential direction (as illustrated in the figures 3 ,10 The first and second platforms are attached and fixed respectively to the intermediate housing 22 (in particular the ferrules). The stator blades 34 and the first and second platforms 95, 96 are monoblocs so as to form at least one straightening assembly attached between two aerodynamic elements 33 (circumferentially). Six stator blades 34 each extend radially between the first and second platforms 95, 96. These stator blades 34 advantageously have an identical axial chord.

[0046] In general, the intermediate casing 22 comprises about six aerodynamic elements 33 distributed regularly around the longitudinal axis and at least forty stator blades 34 installed around the longitudinal axis also (and between the aerodynamic elements 33 circumferentially).

[0047] As we can see on the figure 4 The radially internal and external platforms 46, 47 form a notch 97 designed to receive the first platform 95 and the second platform 96, respectively. The notches 97 are delimited respectively by the (radially internal or external) edge 78, 87 of a ferrule 31, 32 and two flanks 61, 59 of the adjacent radially internal and external platforms 46, 47, which are spaced apart and face each other in the circumferential direction. The edge 78, 87 and the two flanks 61, 59 have a U-shaped form.

[0048] The second platform 96 includes a downstream edge 94 that abuts the radially external edge 78 of the radially external ferrule 32. Each circumferential end 98 of a second platform abuts a flank 61 of a circumferentially adjacent radially external platform 47. The second platform 96 also includes an upstream edge 99 (axially opposite the downstream edge 94) that has surface continuity with the upstream edge 62 of the radially external platform 47. In other words, the length of the second platform 96 along the longitudinal axis is substantially equal to the length of the radially external platform 47.

[0049] The first platform 95 includes a downstream edge 100 (cf. figure 10 ) which bears against the edge 87 of the radially internal ferrule. Each circumferential end 101 of a first platform 95 bears against a flank 59 of a circumferentially adjacent radially internal platform 46. The first platform 95 also has a radially internal surface 117 which also includes a second layer 118 of abradable material comprising, for example, a metallic or non-metallic material. The second layer 118 of abradable material is aligned in the circumferential direction with the first layer 80 of abradable material of the adjacent radially internal platforms. The first edge 60 of the first layer of material 80 has surface continuity with the second edge 120 of the adjacent second layer 118 of material.The first and second layers 80, 118 of material have the same thickness along the radial axis as well as the same length along the longitudinal axis and the same width transversely.

[0050] On the figure 6 , the second platform 96 is here fixed to the radially external ferrule via fixing members 67. The radially external ferrule 32 comprises an annular radial wall 25 (cf. figures 2 , 8, 9 ) which extends radially outwards from a superior surface 63 (cf. figure 2 ) of the radially external ferrule 32. The radial wall 25 has, along an axial section, a general T-shape with two opposite branches which each extend radially (called lower branch 64 and upper branch 65) and an axial leg 66. The lower branch 64 is connected to the radially external ferrule and the upper branch 65, extending radially outwards, is intended to be connected to a fixed structure of the turbomachine.

[0051] In the embodiment example, the second platform 96 includes legs 102 (four legs as shown on the figure 3 ) which extend radially outwards from a radially external surface 103 of the second platform 96. Each leg 102 has a generally U-shaped axial cross-section with two branches (hereafter referred to as the first branch 104 and the second branch 105) and a base 106. A rib 107 connects the base of each leg to the second platform 96. The rib 107 is also connected to the first branch 104. The rib 107 is located in a median area of ​​the leg along the circumferential direction in the installed position. The first branch 104 is defined in a plane that has an open angle of approximately 75° with the plane in which the base is defined. On the other hand, the plane of the bottom 106 forms an angle of approximately 90° (right) with the second branch 105. The first branch 104 rises from the radially external surface 103. The bottom 106 is in contact with the lower branch 64 of the radial wall of the radially external ferrule.The second arm 105 rests against and is fixed with the fastening elements 67 to the axial leg 66 of the radial wall. In the installed position, the plane of the second arm 105 is parallel to that in which the axial leg 66 is defined. Similarly, the plane of the base 106 of the leg is also parallel to the plane of the lower arm 64.

[0052] The second branch 105 includes an opening (not shown) passing through it on both sides along an axis parallel to the radial axis. This opening is intended to be aligned with a orifice passing through 123 (one of which is shown in dashed form on the figure 6 ) which comprises the axial leg 66. The axial leg 66 includes several through holes 123 whose axes are substantially parallel to the radial axis. Each opening and its corresponding through hole 123 are designed to cooperate with the fasteners and are evenly distributed along the circumferential direction. The fasteners 67 can provide a threaded connection and can be of the screw, stud, nut, or bolt type. We see a screw 70 passing through each through hole 123 and opening, and a nut 124 tightening the second arm 105 onto the axial leg 66. The nut 124 is advantageously, but not exclusively, a riveted nut. A washer 72 is arranged between the head 71 of the screw 70 and the axial leg 66 of the radial wall of the radially external ferrule. The fastening here is called radial.

[0053] With reference to the figure 7 , the first platform 95 is also fixed to the intermediate casing via fixing devices 67 substantially similar to those described above (screws, bolts, nuts, studs, bolts, any element allowing easy assembly and / or disassembly). The first platform comprises a base 109 extending to its downstream end 82. The first platform and the base here have a substantially V-shaped axial cross-section. The base 109 has a generally T-shaped axial cross-section with an upstream arm 83, a downstream arm 84, and a radial leg 85. The downstream arm 84 extends along the longitudinal axis and comprises a downstream end 86 designed to abut an annular flange 89 defined in a radial plane of the radially internal ferrule 31. The downstream arm 84 is designed to be arranged radially outside a circumferential face of an annular bearing surface 88 of the radially internal ferrule 31.The upstream branch 83 also extends axially. As for the radial leg 85, the latter is intended to bear against the annular span 88 which is defined in a plane perpendicular to the longitudinal axis. The annular span includes several holes 90 (cf. . figure 4 ) which are arranged regularly around the longitudinal axis. Each 90° hole has an axis substantially parallel to the longitudinal axis. In this embodiment example (illustrated on the figure 4 ) there are four holes.

[0054] The radial leg 85 includes a hole 93 (cf. figure 8 ) passing through it from both sides along the longitudinal axis X. Each hole is designed to cooperate with a bore 90 in the annular bearing surface 88 and to receive a screw cooperating with an insert. A washer 72 is provided between the screw head 71 and the radial leg 85. At least one reinforcement 91 also extends between the radially internal surface 79 of the base and the radially internal surface 117 of the first platform 95 so as to provide rigidity to the latter. Several reinforcements (here twelve on the figure 3 ) are distributed regularly around the longitudinal axis. Each reinforcement has a generally triangular axial section with an opening 92 which passes through it on both sides in the circumferential direction (in installation situation) so as not to impact the mass of the turbomachine.

[0055] Another embodiment of a rectification assembly is illustrated in the figures 8 et 9 In particular, the second platform 96 is attached to and fixed onto the intermediate housing 22 by means of a radial mounting flange 130. This flange extends radially from the radially external surface 103 of the second platform 96, and circumferentially around the entire periphery of the second platform 96. The radial mounting flange 130 has a general L-shaped axial cross-section with a first axial wall 131 and a second radial wall 132. The first axial wall 131 extends from the radially external surface 103 of the second platform 96. The second radial wall 132 extends along the radial axis from one end of the first axial wall 131.The second radial wall 132 has a bearing surface (perpendicular to the longitudinal axis) which is intended to bear (plane on plane) against the lower branch 64 of the radial wall 25 of the radially external ferrule 32 as illustrated on the . figure 9 This allows for better positioning of the straightening assembly on the intermediate housing 22. The second radial wall has a lower height than the lower arm 64. It therefore stops just below the axial leg 66 of the radial wall 25. Openings 68 pass through the radial wall 25 on both sides and are regularly spaced around the longitudinal axis. Each of these openings 68 has an axis substantially parallel to the longitudinal axis. The radial mounting flange 130 includes axial holes 133 that pass through it on both sides. The openings 68 and the axial holes 133 are respectively opposite each other on the figure 8 These are designed to cooperate with fastening elements 67 that provide axial fixation. In the illustrated example, a screw cooperating with an insert is inserted into an axial bore 133 and a corresponding orifice. A washer 72 is installed between the screw head 71 and the second radial wall 132.

[0056] The first platform 95 is fixed to the internal radially mounted ferrule 31 in a manner similar to that of the figure 7 The axial fixing here achieves an axial locking of the first platform on the intermediate housing 22.

[0057] Following yet another embodiment illustrated on the figures 10 And 11The straightening assembly is attached to and fixed radially on the inner and outer flanges 31, 32. The radial mounting flange 130 includes axial holes 133 that pass through it on both sides and cooperate with the openings 68 in the radial wall 25. Fasteners 67 (screws, inserts, washers) secure the mounting flange 130 to the radial wall 25. This embodiment differs from the previous embodiment in that the first and second platforms include first and second slots 135, 136, which are designed to receive, respectively, the radially inner and outer ends 38, 39 of the stator blades 34, which are attached to them. In particular, each first slot 135 and second slot 136 passes through the platforms 95, 96 on both sides along the radial axis.These first and second slots 135, 136 are also regularly distributed around the longitudinal axis. The radially external end 38 of each stator blade 34 is integral with a head platform (or thrust plate) 137, which has a dimension larger than that of the slots. The latter have a shape complementary to that of the blades. More precisely, their dimensions are equal to or slightly larger (by about +0.2 mm) than those of the blade 37 of the stator blade 34, so as to allow the passage of a blade. The head platform 137 rests on the radially external surface 103 of the second platform 96. Advantageously, but not exclusively, the head platforms 137 are welded to the second platform 96.

[0058] As regards the radially inner end 38 of the blades 37, these cooperate with at least one locking device 139 to hold them on the first platform 95. For this purpose, each radially inner end 38 includes an opening 138 which passes transversely through the blade on both sides. Each opening 138 has an oblong or elongated shape along a direction substantially parallel to the longitudinal axis. As we can see more precisely on the figure 11 A locking device 139 includes a fastener 140 which is inserted into at least one opening 138 so as to allow radial locking of the radially internal end on the first platform 95. Each fastener 140 has a cross-section substantially complementary to the axial cross-section of the opening. On the figure 11 A fastener 140 is slid into two adjacent stator blade openings 138. The locking device 139 also includes a rod 141 and a stop 142, the rod 141 being free at one end and connected at the other end to the stop 142. The stop 142 also extends transversely between two radially internal ends of the blades so as to hold them in position relative to each other.

[0059] Another embodiment of the intermediate casing is illustrated on the figures 12 à 14 We see that the aerodynamic elements 33 are monobloc (made from a single piece) with radially internal and radially external ferrules. The first platform 95 and the second platform 96 are also monobloc with radially internal and radially external ferrules. Advantageously, the intermediate housing (with the monobloc ferrules and aerodynamic elements) is cast. The first platform 95 and the second platform 96 are continuous between two aerodynamic elements 33. The first and second platforms include, respectively, first and second slots 135', 136', which are designed to receive the radially internal and external ends of the stator blades 34. The slots 135', 135' pass radially through the walls of the first and second platforms 95, 96. The stator blades 34 are mounted on these slots.The stator blades 34 are made separately from the first and second platforms 95, 96 and the rest of the intermediate housing components. In particular, each stator blade 34 is slid radially into a first slot 135' of the first platform 95 towards the corresponding second slot 136'. The radially inner end 38 of each stator blade is in this case fitted with a stop platform (or foot platform) 137' (illustrated precisely on the figure). figure 13 ) which comes against the radially internal surface of the first platform 95. The radially external ends are each fixed to the second platform 96. Advantageously, but not exclusively, the radially internal ends are fixed by welding. Each thrust plate 137' is also welded to the first platform 95. Here, the intermediate housing is formed from several one-piece angular sectors. Alternatively, the intermediate housing can be formed by creating a single wheel comprising the radially internal ferrule 31 (with the first platform 95 formed from material) and the radially external ferrule 32 (with the second platform 96 formed from material). Such a configuration facilitates maintenance of the housing by requiring intervention only on the damaged stator blade(s), thus reducing maintenance and manufacturing costs.

[0060] With reference to figures 9And 14 The compressor housing 21 is fixed to the intermediate housing 22 at the radial wall 25. The compressor housing 21 includes a bottom wall 122 defined in a plane containing the radial axis. This bottom wall 122 is designed to be fixed to the radial wall 25, and in particular to the upper arm 65. The axial leg 66 centers the compressor housing on the radial wall 25 of the intermediate housing 22. The bottom wall 122 extends radially above the axial leg 66. The bottom wall includes openings allowing the passage of fasteners onto the axial leg 66.

Claims

1. An annular intermediate casing (22) for a turbomachine (1) of longitudinal axis X, in particular, for an aircraft, through which an aerodynamic air flow is intended to circulate at least in part, the intermediate casing (22) comprising: - an annular radially inner shroud (31), - an annular radially outer shroud (32), - at least one stator vane (34) extending substantially along a radial axis Z, the stator vane (34) comprising a blade (37) with a leading edge (42) and a trailing edge (43), and - at least one aerodynamic member (33) which is formed of a structural arm (35) extending radially at least in part between the radially inner shroud (31) and the radially outer shroud (32), characterised in that the stator vane extends between a first platform (95) and a second platform (96) and the aerodynamic member (33) comprises a leading edge (51) which is aligned with the leading edge (42) of the stator vane (34) in a plane (P) perpendicular to the longitudinal axis X, the leading edge (51) of the aerodynamic member (33) being borne by a profiled portion (36) positioned upstream of the structural arm (35) in the direction of circulation of the aerodynamic air flow, the profiled portion (36) and the structural arm (35) being monobloc, and in that the aerodynamic member (33) is monobloc with the radially inner shroud (31) and the radially outer shroud (32), the intermediate casing (22) comprising at least two aerodynamic members (33) spaced along the circumferential direction about the longitudinal axis X and a straightening assembly which is added on between the two aerodynamic members (33) and which are distinct from the two aerodynamic members (33), the straightening assembly comprising the first platform (95), the second platform (96) and a plurality of stator vanes (34) extending radially between the first and second platforms (95, 96) and being distributed regularly along the circumferential direction, each leading edge (42) of the plurality of stator vanes (34) is aligned with the leading edge (51) of the aerodynamic member in the plane (P) perpendicular to the longitudinal axis X.

2. The intermediate casing (22) according to the preceding claim, characterised in that the profiled portion (36) extends radially between a radially inner platform (46) and a radially outer platform (47), the radially inner and radially outer platforms being respectively monobloc with the radially inner shroud (31) and the radially outer shroud (32), and in that the radially inner platform (46) has a radially inner surface (79) bearing a first layer (80) of abradable material.

3. The intermediate casing (22) according to the preceding claim, characterised in that the first platform (95) and the second platform (96) are added on and fixed to the radially inner shroud (31) and the radially outer shroud (32) respectively, the first platform (95) having a radially inner surface (117) bearing a second layer (118) of abradable material, the second layer of abradable material (118) being aligned along the circumferential direction with the first layer (80) of abradable material.

4. The intermediate casing (22) according to any one of the preceding claims, characterised in that the first platform (95) comprises a base (109) which is fixed to an annular range (88) of the radially inner shroud (31) with at least one fixing member (67) providing an axial fixation.

5. The intermediate casing (22) according to any one of the preceding claims, characterised in that the second platform (96) is fixed to a radial wall (25) of the radially outer shroud (32) which extends radially towards the outside from a radially outer surface (63) and via at least one fixing member.

6. The intermediate casing (22) according to the preceding claim, characterised in that the second platform (96) has tabs (102) each extending from its radially outer surface (103), each tab (102) being fixed to an axial leg (66) of the radial wall (25) with the fixing members (67) providing a radial fixation.

7. The intermediate casing (22) according to claim 6, characterised in that the second platform (96) comprises a radial attachment flange (130) extending radially towards the outside from its radially outer surface (103) and along the circumferential direction on its entire periphery, the radial attachment flange (130) being fixed to a lower branch (64) of the radial wall (25) that extends along the radial axis and with the fixing members (67) providing an axial fixation.

8. The intermediate casing (22) according to any one of the preceding claims, characterised in that the straightening assembly is monobloc.

9. The intermediate casing (22) according to any one of the preceding claims, characterised in that the leading edge (51) of the aerodynamic member is located at an axial distance (Dx) from a zone of intersection between the profiled portion (36) and the structural arm (35), and in that the zone of intersection has a thickness (e1) along the circumferential direction substantially equal to three times the master torque of the profiled portion (36).

10. The intermediate casing (22) according to any one of the preceding claims, characterised in that the stator vane (34) has an axial chord (Cx) measured between its leading edge (42) and its trailing edge (43) and in that the profiled portion (36) has an axial length measured between the leading edge (51) of the aerodynamic member (33) and the zone of intersection substantially equal to the axial chord (Cx).

11. The intermediate casing (22) according to any one of the preceding claims, characterised in that it is made by casting or additive manufacturing.

12. An annular intermediate casing (22) for a turbomachine (1) with a longitudinal axis X, in particular, for an aircraft, through which an aerodynamic air flow is intended to circulate at least in part, the intermediate casing (22) comprising: - an annular radially inner shroud (31), - an annular radially outer shroud (32), - at least one stator vane (34) extending substantially along a radial axis Z, the stator vane (34) comprising a blade (37) with a leading edge (42) and a trailing edge (43), and - at least one aerodynamic member (33) which is formed of a structural arm (35) extending radially at least in part between the radially inner shroud (31) and the radially outer shroud (32), characterised in that the stator vane extends between a first platform (95) and a second platform (96) and the aerodynamic member (33) comprises a leading edge (51) which is aligned with the leading edge (42) of the stator vane (34) in a plane (P) perpendicular to the longitudinal axis X, the leading edge (51) of the aerodynamic member (33) being borne by a profiled portion (36) arranged upstream of the structural arm (35) along the direction of circulation of the aerodynamic air flow, the profiled portion (36) and the structural arm (35) being monobloc, and in that the aerodynamic member (33) is monobloc with the radially inner shroud (31) and the radially outer shroud (32) and in that the first platform (95) is monobloc with the radially inner shroud (31) and the second platform (96) is monobloc with the radially outer shroud (32), the first and second platforms (95, 96) each comprising respectively a plurality of slots (135, 135', 136, 136') of complementary shape with the blades (37) of the stator vanes (34) which are distributed regularly about the longitudinal axis X, each stator vane (34) comprising a radially inner end (38) which is received in a corresponding first slot (135, 135') of the first platform (95) and a radially outer end which is received in a corresponding second slot (136, 136') of the second platform (96).

13. The intermediate casing (22) according to the preceding claim, characterised in that each of the radially outer or inner ends is secured to an abutment platform (137, 137') lying radially towards the outside of a first or second platform (95, 96) and the other of each of the radially inner or outer ends radially opposite is locked or fixed to the first or second platform.

14. The intermediate casing (22) according to the preceding claim, characterised in that the locking or fixing is achieved by a locking device (139) or a weld.

15. A dual flow turbomachine (1) with a longitudinal axis X, in particular, for aircraft, comprising: - at least one fan (2) generating an air flow and comprising at least one annular row of fan blades (2b) carried by a hub (30) of longitudinal axis X, - a splitter nose (17), downstream of the row of fan blades (2b) separating the air flow into a primary flow circulating in an annular primary vein (14) and a secondary flow circulating in an annular secondary vein (15), - at least one compressor (4, 5) arranged downstream of an inlet to the primary vein formed of an annular edge of the splitter nose (17) and comprising annular rows of movable vanes (4a) and guide vanes (4b), and - at least one turbomachine intermediate casing (22) according to any one of the preceding claims, the intermediate casing (22) comprising a plurality of stator vanes (34) distributed around the longitudinal axis X so as to straighten the air flow leaving the last row of movable vanes (4a) of the compressor.