Composite outer race for an intermediate case of an aircraft turbine engine

Abstract

The invention relates to an external collar (23) for an intermediate casing (21) of an aircraft turbine engine, made of composite material, comprising a downstream annular connection end (46) forming a peripheral groove (48) and intended to receive a complementary connection part (50) provided on one or more nacelle covers (38), made of: - a first fibrous preform (64) obtained by three-dimensional weaving of threads and densified by a matrix, the preform (64) defining a barrel (45) of the collar and a structural portion (66) of a downstream groove wall (58); - a second fibrous preform (68) obtained by three-dimensional weaving of threads and densified by a matrix, the preform (68) defining a base (82) in abutment with the outside of the barrel (45) defined by the first preform (64) and a structural portion (72) of an upstream groove wall (52).

Description

Technical Field

[0001] This invention relates to the field of intermediate housings for aircraft turbine engines, and more specifically, to the manufacture of outer rings for such intermediate housings.

[0002] For example, the intermediate casing ring of an aircraft turbine engine is known from document FR2925120A1. Background Technology

[0003] It is known that masts (also known as "engine mounting structures" or "engine pylons") used to mount turbine engines typically suspend the turbine engine from the wing of an aircraft. In fact, a connection interface is defined between the turbine engine and a given structural part of the aircraft (typically the canard wing cavity). This connection interface allows the forces generated by the turbine engine to be transmitted to the structure of the aircraft, and also allows for the routed flow of electrical, hydraulic, and air systems, as well as fuel, between the turbine engine and the aircraft.

[0004] For the nacelle, it is typically equipped with multiple covers that surround the turbine engine and allow access to the turbine engine in the open position. These covers are called fan covers and thrust reverser covers, and they are hinged to the main structure of the attachment pylons.

[0005] The turbojet engine includes a fan casing that extends rearward through a so-called intermediate casing, which includes an outer ring, an inner hub, and structural arms that are angled and extend radially between the outer ring and the hub, where the structural arms are joined.

[0006] Therefore, the intermediate housing corresponds to the structural element arranged between the upstream fan housing and the downstream nacelle. More precisely, the annular downstream end of the intermediate housing is dedicated to providing an interface between the intermediate housing and the nacelle (typically the thrust reverser housing).

[0007] The annular downstream end of the intermediate housing forms an annular or substantially annular peripheral groove that opens radially outward. This groove is used to receive a complementary connecting member disposed on the thrust reverser housing, and is further defined by an upstream groove wall and a downstream groove wall, both of which are radial walls. Therefore, the complementary connecting member can be an inwardly extending radial rib to be received within the groove located between the upstream and downstream walls.

[0008] The fit between the ribs and the grooves allows aerodynamic forces (especially axial forces, and even more so the reverse thrust axial forces when the thrust reverser system equipped on the cabin cowl is engaged) to be transferred from the cabin to the turbine engine during takeoff, flight, and landing.

[0009] This arrangement (characterized by the simple insertion of ribs into grooves) allows the reversing cover, hinged to the pylon, to be opened easily and quickly, for example, to perform maintenance operations on aircraft parked on the ground.

[0010] Several solutions are known for manufacturing the outer collar of the intermediate shell, including a cylinder designed to produce the collar from a composite material and a downstream metal end structure to which a defining groove is added.

[0011] Therefore, the outer ring's cylinder is made of a composite material, typically a fiber reinforcement densified by a matrix (preferably a resin, such as epoxy resin). In this case, the cylinder is made of a fiber preform, which can be obtained in various ways known to those skilled in the art, typically by three-dimensional weaving of threads (3D weaving) or by draping two-dimensional fiber fabrics.

[0012] The use of composite materials for the outer ring cylinder reduces the mass of the turbine engine, but this mass is still affected by the presence of the downstream metal end structure that defines the peripheral groove and the mechanical fastening components (such as bolts) required at the interface.

[0013] Therefore, the object of the present invention is to further reduce the mass of the outer ring of the intermediate housing, while proposing a design that facilitates the manufacture of the outer ring. Summary of the Invention

[0014] To achieve the above objectives, the present invention primarily aims to provide an external collar for an intermediate housing of an aircraft turbine engine, the collar being made of a composite material, the collar including a downstream end of an annular connection forming a radially outwardly opening peripheral groove for receiving complementary connecting components disposed on one or more nacelle canopies, and the groove being defined by an upstream groove wall and a downstream groove wall.

[0015] According to the present invention, the ferrule is made of the following components:

[0016] - A first fiber preform, obtained by three-dimensional weaving of threads and densified by a matrix, the first preform defining a cylindrical body of the collar and a structural portion of the downstream groove wall that projects radially outward relative to the cylindrical body; and

[0017] - A second fiber preform or a set of second fiber preforms, each second fiber preform being obtained by three-dimensional weaving of threads and densified by a matrix, the second preform or the set of second preforms defining: a base externally attached to a cylinder defined by a first preform; and a structural portion of the upstream groove wall that projects radially outward relative to the cylinder.

[0018] Because of its "fully composite" design and the absence of mechanical fastening components such as bolts, this invention offers the advantage of reduced weight. This reduction in the mass of the outer raceway contributes to a reduction in the specific fuel consumption of the turbine engine, and thus makes it suitable for programs aimed at reducing greenhouse gas emissions.

[0019] Furthermore, the present invention advantageously provides the generation of the peripheral groove using two preforms, thereby simplifying the shape of the preform and thus facilitating its production. The downstream groove wall experiences the greatest mechanical stress during the thrust-reversal phase, demonstrating the particular wisdom of incorporating this structural portion of the downstream wall within a single preform, which also defines the cylinder of the collar, corresponding to the most critical structural portion of the outer intermediate shell collar. Since the upstream groove wall, in itself, retains relatively low mechanical stress through the nacelle cover, forming it by a dedicated preform attached to the other preform constitutes a perfectly suitable technical solution.

[0020] Preferably, the present invention provides at least one of the following optional features, which may be considered individually or in combination.

[0021] Preferably, in the case of a single second fiber preform, i.e., having a single second 3D braided fiber preform having an annular or substantially annular shape centered on the longitudinal central axis of the loop, and in another case of a group of second fiber preforms, each of the group of second fiber preforms is in the form of a corner sector to collectively form an annular or substantially annular structure centered on the longitudinal central axis of the loop.

[0022] Preferably, the ferrule includes a non-friction covering layer that covers the upstream and downstream recess walls inside the recess. The non-friction covering layer is preferably a fabric or foil. The non-friction covering layer reduces friction between the outer ferrule and the nacelle housing at the recesses forming the interface between these components. This limits wear on these components and increases their service life.

[0023] Preferably, the ferrule further includes a third fiber preform or a set of third fiber preforms, each third fiber preform being obtained by three-dimensional weaving of the yarn and densified by a matrix. The third preform or set of third preforms defines: a base attached from the inside to the cylinder defined by the first preform; and a structural gasket span portion axially projecting downstream beyond the downstream groove wall. Each of the third preforms or set of third preforms is preferably dispersed during weaving to also define an additional base attached from the outside to the downstream groove wall. While such an additional base is still optional, it should be noted that this additional base enhances the mechanical strength of the structural gasket span portion.

[0024] Another object of the present invention is an aircraft turbine engine comprising such an external intermediate casing ring. Without departing from the scope of the invention, the turbine engine is preferably a turbojet engine, preferably a bypass and / or twin-shaft type, but other types of turbine engines, such as turboprop engines, are also conceivable. Very preferably, the present invention relates to a turbojet engine with a very high bypass ratio, also known as an ultra-high bypass ratio (UHBR) turbojet engine.

[0025] Another object of the present invention is a method for manufacturing an outer ring for an intermediate housing of an aircraft turbine engine, the ring being made of a composite material, the ring including an annular connection downstream end forming a peripheral groove that opens radially outward, the groove for receiving complementary connecting parts disposed on one or more nacelle covers, and the groove being defined by an upstream groove wall and a downstream groove wall.

[0026] According to the present invention, the method includes the following steps:

[0027] - Generate a first fiber preform, which is obtained by three-dimensional weaving of threads and densified by a matrix. The first preform defines a structural portion of the cylinder of the collar and a downstream groove wall, the structural portion projecting radially outward relative to the cylinder; and

[0028] - Generate a second fiber preform or a set of second fiber preforms, each second fiber preform being obtained by three-dimensional weaving of threads and densified by a matrix, the second preform or the set of second preforms being used to define a base and a structural portion of the upstream groove wall that protrudes radially outward relative to the cylinder;

[0029] - Injection and polymerization of the matrix used to densify the first preform; and

[0030] - Injection and polymerization are used to densify the matrix of the second preform or a set of second preforms, so that the base is fixedly attached to the cylinder of the collar from the outside.

[0031] Compared to the outer ring, which also serves the purpose of this invention, the advantages associated with this manufacturing method are those mentioned above. As will be detailed below, the various steps of the injection matrix can be performed simultaneously or continuously through co-injection.

[0032] This is because, for example, it is arranged such that the injection of a matrix for densifying the first preform and the injection of a matrix for densifying the second preform or a group of second preforms are co-injected via the matrix, preferably simultaneously in a flexible injection tool, a rigid mold matrix transfer tool, or a hybrid tool of flexible injection and rigid mold matrix transfer. The injection technique sought with a rigid mold matrix transfer tool is preferably resin transfer molding or RTM. The injection technique sought with a flexible injection tool is preferably performed in an impregnation chamber partially defined by a flexible, impermeable membrane. As known, for example, from document WO2018 / 234669A1, this technique can optionally be achieved by means of a compaction chamber separated from the impregnation chamber by the membrane.

[0033] One or the other of these two preferred injection techniques can actually be used to produce outer rings, or the two preferred injection techniques can preferably be combined.

[0034] According to another example of manufacturing the outer ring, firstly, preferably in a rigid mold matrix transfer tool, a matrix for densifying the first preform is injected and polymerized. Then, in a subsequent curing step, preferably in a rigid mold matrix transfer tool, a matrix for densifying the second preform or a group of second preforms is injected and polymerized. In this example, the consolidation of the second preform or a group of second preforms thus occurs after the consolidation of the first preform. Still in this example, other types of tools and other injection methods can be used without departing from the scope of the invention.

[0035] Preferably, the method includes generating a non-frictional coating layer covering the upstream and downstream groove walls inside the groove. The non-frictional coating layer is preferably generated by co-curing during the curing of a first preform and a second preform or a set of second preforms, or the non-frictional coating layer is bonded to the upstream and downstream groove walls after curing.

[0036] Preferably, the method further includes:

[0037] - Generate a third fiber preform or a set of third fiber preforms, each third fiber preform obtained by three-dimensional weaving of threads, the third preform or set of third preforms serving to define a base and a structural gasket span that axially protrudes downstream beyond the downstream groove wall; and

[0038] - Injection and polymerization are used to densify the matrix for the third preform or a group of third preforms, so that the base is fixedly attached to the cylinder of the collar from the inside.

[0039] Similarly, the curing of the third preform or a group of third preforms can also be accomplished by co-curing during the curing of the first preform or during a subsequent curing step.

[0040] Finally, the method may further include generating a non-friction capping layer that covers the span of the structural gasket. In this case, the non-friction capping layer is preferably generated by co-curing during the curing of a third preform or a group of third preforms, or bonded after said curing.

[0041] Other advantages and features of the invention will become apparent in the following non-limiting detailed description. Attached Figure Description

[0042] The description will refer to the accompanying drawings, in which;

[0043] [ Figure 1 The image shows an axial half-sectional view of an aircraft turbine engine according to a preferred embodiment of the present invention;

[0044] [ Figure 2 This figure shows a perspective view of the outer ring of the intermediate housing equipping the turbine engine shown in the foregoing figures;

[0045] [ Figure 3 [This is an enlarged partial view showing the fit between the outer intermediate shell ring and the nacelle cover in an axial section;]

[0046] [ Figure 4 This shows a partial view of an axial half-section of the outer ferrule prior to the matrix injection and matrix polymerization steps of the outer ferrule;

[0047] [ Figure 5 The diagram illustrates the interaction between the matrix injection and polymerization steps. Figure 4 Similar views;

[0048] [ Figure 6 ] is with Figure 4 A similar view of the outer collar in another embodiment;

[0049] [ Figure 7 ] is with Figure 6 A similar view of the outer collar in the form of another embodiment. Detailed Implementation

[0050] First refer to Figure 1 The illustration shows an aircraft turbine engine 1 according to a preferred embodiment of the invention. Here, the aircraft turbine engine is a bypass twin-shaft turbojet engine. However, without departing from the scope of the invention, the aircraft turbine engine can be another type of turbine engine, such as a turboprop engine.

[0051] The turbojet engine 1 has a central longitudinal axis 2 around which its various components extend. The turbojet engine includes, from upstream to downstream, a fan 3, a low-pressure compressor 4, a high-pressure compressor 6, a combustion chamber 11, a high-pressure turbine 7, and a low-pressure turbine 8, depending on the main direction 5 of the airflow passing through it.

[0052] Typically, after passing through the fan, the air is divided into a main flow 12a centered on the main flow and a secondary flow 12b surrounding the main flow. The main flow 12a flows in a main duct that allows gas to pass through compressors 4 and 6, combustion chamber 11, and turbines 7 and 8. The secondary flow 12b itself flows in a secondary duct that is radially outwardly defined by the engine housing, which is surrounded by the engine compartment 32.

[0053] The engine housing is divided into multiple elements, including an intermediate housing 21 that includes an outer ring 23 located aerodynamically downstream of the fan housing 12. The intermediate housing 21 also includes a hub 26 formed by transverse plate-like members 25, 27 radially disposed internally relative to the outer ring 23. The housing 21 also includes structural arms 17 that are angled and extend radially to connect the outer ring 23 and the hub 26.

[0054] The turbojet engine also includes a center casing 16 (also referred to as the "core" casing), which causes the hub 26 of the intermediate casing 21 to extend downstream, and the center casing is connected to the hub. It should be noted that the center casing extends to the rear end 19 (also referred to as the jet casing) with the largest dimensions.

[0055] It is known, and will be described in detail below, that the outer collar 23 of the intermediate housing includes a downstream end for connection with a peripheral recess, the primary purpose of which is to establish a connection between the outer collar 23 and the nacelle cover directly adjacent downstream.

[0056] The nacelle 32 forms a continuous aerodynamic outer surface through adjacent elements that follow each other from upstream to downstream, including an air intake 34, a fan shroud 36, a thrust reverser shroud 38, and a fixed rear shroud 40.

[0057] The thrust reverser cover 38 is typically two in number, hinged to a rigid structure for attaching the turbojet engine 1, and defines the annular secondary flow passage 42 in a known manner by an outer annular skin 44 and an inner annular skin 43.

[0058] Each thrust reverser cover 38 (also referred to as the rear cover or “core” cover) is in the form of a semi-cylindrical shape, with the top end of each thrust reverser cover intended to be hinged to a rigid structure of the mount, and the bottom end of each thrust reverser cover intended to be locked to the bottom end of another cover 38 by conventional means.

[0059] Therefore, each thrust reverser cover 38 is connected to the annular downstream end via its upstream end and in its closed position for connecting the outer collar 23 of the intermediate housing. Figure 2 The outer ring 23 is shown at a larger scale, while Figure 3 This illustrates the fit between the collar 23 and the thrust reverser cover 38 (in this...) Figure 3 Only one of the thrust reverser covers is visible in the image.

[0060] An outer collar 23 (also an object of the invention) extends around a longitudinal central collar axis corresponding to axis 2 of the turbojet engine. The structural portion of the outer collar 23 is entirely made of composite material to form a single piece, which, from upstream to downstream, sequentially includes an upstream radial flange 42 for attachment to the fan housing, a generally cylindrical collar body 45 having a circular cross-section, and a final annular downstream connecting end 46. This forms an annular or generally annular peripheral groove 48 that opens radially outward. This groove 48 may be interrupted by notches 51, for example by two axial notches 51 that pass through the annular downstream connecting end 46 at opposite clock positions in diameter (such as 12 o'clock and 6 o'clock as known to those skilled in the art).

[0061] The groove 48 is, for example, generally V-shaped and receives a rib 50 disposed on the upstream end of each thrust reverser cover 38. Figure 3 As shown, the ribs 50 preferably extend radially inward and have a generally V-shaped shape that complements the shape of the groove 48. Each rib 50 preferably extends over an angular sector of approximately 180°, or over a slightly smaller angular value. Thus, each rib constitutes a complementary connecting member that mates with the groove 48 to create an interface between the collar 23 and each cover 38.

[0062] The annular groove 48 is first defined axially by the upstream groove wall 52 and then axially by the downstream groove wall 58. Each of these walls 52, 58 extends radially outward relative to the cylinder 45 and each wall has an annular shape centered on axis 2, or approximately annular if an axial notch 51 is formed.

[0063] The fit between the peripheral groove 48 and each complementary rib 50 allows aerodynamic forces (particularly axial forces, and even more particularly axial thrust reversers) to be transmitted from the thrust reverser cover 38 to the turbojet engine.

[0064] Downstream of the downstream recess wall 58, the connecting end 46 includes a structural gasket span 60. This span 60 is positioned to project axially downstream relative to the downstream recess wall 58, and it receives a gasket 62 carried by the upstream end of the thrust reverser cover 38. Therefore, as Figure 3 As shown, when the cover 38 is closed, the gasket 62 can be pressed against the structural span 60, but the gasket can also be pressed against the downstream surface of the downstream groove wall 58.

[0065] Now refer to Figure 4 The diagram shows the various components used to manufacture the outer ring 23. It should be noted that the design, referred to as "fully composite," results in no mechanical attachments between the various parts of the outer ring, and thus eliminates the need for bolts, rivets, etc.

[0066] exist Figure 4 The state of each element constituting the collar 23 shown corresponds to the state before the element is impregnated with a resin-type (preferably epoxy) matrix, and thus before one or more steps leading to resin polymerization / consolidation. Therefore, Figure 4 Particularly shown are fiber preforms produced entirely through 3D weaving of threads, which are intended to be densified by subsequent resin injection. Typically, the fibers used to produce the preforms are carbon fibers, although other conventional materials are conceivable without departing from the scope of the invention.

[0067] First, a first fiber preform 64 is provided, which is intended to define a ferrule for attachment (in Figure 4The structural portion 66 of the upstream flange, the cylinder 45, and the downstream recessed wall 58 (not visible in the middle) extends radially outward relative to the cylinder. This structural portion 66, defined by the first preform 64, extends over the entire radial length of the ultimately formed downstream recessed wall 58, or approximately over the entire length of the ultimately formed downstream recessed wall. Therefore, the first preform 64 is preferably annular, centered on axis 2, and has a generally U-shaped half-section.

[0068] Next, a second fiber preform 68 or a set of second fiber preforms is provided. The choice between these two solutions depends on the desired production method of the upstream groove wall 52, either as a continuous monolithic piece in the circumferential direction or as sectored pieces in that direction. In the first case of a single second fiber preform 68, the single second fiber preform has an annular or substantially annular shape centered on axis 2, and in the second case of a set of second fiber preforms, each of the second fiber preforms in the set is in the form of a corner sector to collectively form an annular or substantially annular structure centered on the same axis 2. This is, for example, the case of two corner sectors, i.e., each corner sector is approximately 180°.

[0069] In the following text, only the first case will be considered. However, when the upstream groove wall 52 is produced in a sector, the principle remains the same or similar, which may be due to the presence of the aforementioned axial notch on the collar 23.

[0070] Therefore, the second fiber preform 68 is woven to define a base 70 at the downstream end of the cylinder 45, which is intended to be fixedly and externally attached to the cylinder, and to define a structural portion 72 of the upstream groove wall 52 that projects radially outward relative to the cylinder 45.

[0071] The structural portion 72 of the upstream groove wall 52 can be inclined upstream, rather than being strictly radial like the structural portion 66 of the downstream groove wall 58, thereby obtaining the approximate V-shaped shape required for the groove 48. In this case, the hollow portion defined by the connection radius between the outer surface of the base 70 and the structural portion 72 can be filled with a filler material 74 (preferably a polymerizable material).

[0072] A structural portion 72, which is annular or substantially annular in shape, extends radially outward relative to the cylinder 45 and the base 70. The structural portion 72, defined by the second preform 68, extends over the entire radial length of the ultimately formed upstream groove wall 52, or substantially over the entire length of the ultimately formed upstream groove wall. Therefore, the second preform 68 is preferably annular, centered on axis 2, and has a substantially V-shaped half-section that opens axially upstream and radially outward.

[0073] To reduce friction between the two recessed walls 52, 58 and the ribs of the cabin canopy intended to be accommodated in the recess 48, the collar 23 includes a non-frictional covering 76 that mates with all or part of the inner surface of the recess. Specifically, the covering 76 covers both the upstream wall 52 and the downstream wall 58, and more precisely, the two structural portions 72, 66 defined by the preforms 64, 68. As an indication, it should be noted that the non-frictional covering 76, having a V-shape complementary to the shape of the recess 48, may have attachment ribs (not shown) for attachment to the preforms 64, 68, and / or the non-frictional covering may extend radially outward to cover the ends of the structural portions 66, 72 to protect them from impact. This embodiment is known, for example, from document FR2994216A1.

[0074] The non-friction coating 76 may be a woven fabric designed to be impregnated and cured simultaneously with the first fiber preform 64 and the second fiber preform 68. Alternatively, the non-friction coating may be a foil (e.g., a metal foil) bonded to the walls of the grooves 52, 58 during a subsequent stage after the non-friction coating has cured.

[0075] When the above components are positioned, a hollow portion can be formed between the following components:

[0076] - The outer surface of the first preform 64 located at the bottom of the groove 48;

[0077] - Non-friction coating 76; and

[0078] - The connection radius between the structural portion 72 defined by the second preform 68 and the base 70.

[0079] The hollow portion can also be filled with filler material 78, preferably with polymerizable filler material.

[0080] Next, a third fiber preform 80, or a group of third fiber preforms, is provided. Only the first case of a single third fiber preform is described here; however, the principle remains the same or similar when the structural gasket span 60 is produced in sectors.

[0081] Therefore, the third fiber preform 80 is woven to define a base 82 at the downstream end of the cylinder 45, which is intended to be fixedly and internally attached to the cylinder, and also defines a structural gasket span 60 that protrudes axially downstream beyond the downstream groove wall 58.

[0082] Preferably, the third preform 80 is loosely woven to further define an additional base 84, which is intended to be externally attached to the downstream surface of the structural portion 66 defined by the first preform 64. The additional base 84 not only strengthens the mechanical strength of the structural gasket span 80 on the ferrule but also strengthens the structural portion 66 of the downstream recess wall 58, extending along this downstream recess wall, preferably over its entire radial length or substantially over its entire length.

[0083] Therefore, the third preform 80 is preferably annular, centered on axis 2, and has a generally Y-shaped half-section that opens axially upstream and radially outward.

[0084] To reduce friction with the gasket, another non-friction cover 86 may be provided along the downstream outer surface of the additional base 84 and / or the structural span 60.

[0085] The non-friction coating 86 can also be a woven fabric intended to be impregnated and cured simultaneously with the first fiber preform 64, the second fiber preform 68, and the third fiber preform 80. Alternatively, the non-friction coating can be a foil that is subsequently attached by adhesive after the rest of the ferrule has been cured.

[0086] When the third preform 80 is positioned, a hollow portion can be formed between the following elements:

[0087] -The base 82 defined by the third preform 80;

[0088] -Additional base 84 defined by the third preform 80;

[0089] - The connection radius between the structural portion 66 defined by the first preform 64 and the cylinder 45.

[0090] The hollow section can also be filled with filler material 88, preferably with polymerizable filler material.

[0091] Now refer to Figure 5 , Figure 5The step of injecting resin using a mixing tool is shown, the injection of which is intended to impregnate the fiber preforms 64, 68, 80 described with reference to 4, and to impregnate the fabric forming the non-friction covering layers 76, 86.

[0092] The mixing tool 90 can not only achieve co-injection of the resin used for impregnating all components 64, 68, 80, 76, and 86, but also achieve co-curing of the above resins, thereby causing polymerization of the resin of the impregnated components and co-curing of the filler materials 74, 78, and 88.

[0093] For this purpose, the hybrid tool 90 used is, for example, a combination of a rigid mold resin transfer tool 92 (RTM type) and a flexible injection tool 94.

[0094] More precisely, the rigid mold portion 96 is arranged on both sides of the upstream groove wall 52 and the downstream groove wall 58, as well as inside the groove 48. The rigid tool 92 is thus positioned to mate with the annular downstream connecting end of the outer collar 23.

[0095] Furthermore, the flexible injection tool 94 includes a flexible impermeable membrane 98 that covers the outer surface of the cylinder 45 defined by the first preform 64 and extends to the outer surface of the base 70 defined by the second preform 68. One or more gaskets 99 are inserted and compressed between the end of the membrane 98 that rests on the base 70 and one of the rigid mold portions 96 of the RTM tool 92. The membrane 98 provides pressure to the component to be solidified during resin injection by either creating a vacuum in the impregnation chamber defined by the membrane or by a compaction chamber located on the opposite side of the membrane 98.

[0096] Using the mixing tool 90, resin is co-injected to impregnate all fiber elements 64, 68, 80, 76, and 86 in one and the same stage. The heating obtained by the tool also enables the co-curing of these elements, as well as the co-curing of the filler materials 74, 78, and 88. Therefore, the resin associated with all elements 64, 68, 80, 76, 86, 74, 78, and 88 can be copolymerized during one and the same heating stage. After this co-curing stage, the result is a "fully composite" monolithic piece in which all the consolidated / densified elements are firmly adhered to each other.

[0097] Many alternatives are conceivable, particularly because of the optional characteristics of the multiple portions of the race disclosed above, such as non-friction coverings 76, 86, gasket span 60, or additional base 84 when such gasket span is provided. Other alternatives also stem from the fact that all elements of the race do not necessarily need to be cured simultaneously; staged curing can be effectively used to implement continuous curing, rather than a single co-curing as described above.

[0098] Therefore, another preferred implementation is, for example Figure 6 As shown, the third preform 80 includes only the base 82 and not the additional base. For this embodiment, it is still conceivable to co-cure the three preforms 64, 68, and 80, but the third preform 80 can be subsequently cured after the first preform 64 and the second preform 68 have been cured.

[0099] Figure 7 Another preferred embodiment is shown in which the third preform 80 is no longer provided because the spacer span 60 is no longer needed. For this embodiment, it is still conceivable to co-cure the two preforms 64, 68, but after the first preform 68 has been cured (and subsequently used as a support on which the second preform 68 will be cured / densified), subsequent curing of the second preform 68 can be carried out.

[0100] Of course, those skilled in the art can make various modifications to the invention described above by way of non-limiting example only, and the scope of the invention is defined by the appended claims.

Claims

1. An outer ring (23) for an intermediate housing (21) of an aircraft turbine engine, the outer ring being made of a composite material, the outer ring including an annular connecting downstream end (46) forming a radially outwardly opening peripheral groove (48) for receiving complementary connecting parts (50) disposed on one or more nacelle covers (38), and the groove being axially defined by an upstream groove wall (52) and a downstream groove wall (58). Its features are, The outer collar is made of the following components: - A first fiber preform (64), obtained by three-dimensional weaving of threads and densified by a matrix, the first fiber preform (64) defining a structural portion (66) of the outer ring's cylinder (45) and the downstream groove wall (58) projecting radially outward relative to the cylinder; and - At least one second fiber preform (68), each second fiber preform (68) being obtained by three-dimensional weaving of threads and densified by a matrix, the at least one second fiber preform (68) defining: a base (70) externally attached to the cylinder (45) defined by the first fiber preform (64); and a structural portion (72) of the upstream groove wall (52) that protrudes radially outward relative to the cylinder.

2. The outer ferrule according to claim 1, characterized in that, In the case of a second fiber preform (68), the second fiber preform has an annular shape centered on the longitudinal central axis (2) of the outer ferrule, and in another case of a group of second fiber preforms (68), each of the second fiber preforms in the group of second fiber preforms is in the form of a corner sector to collectively form an annular structure centered on the longitudinal central axis (2) of the outer ferrule.

3. The outer ferrule according to claim 1 or claim 2, characterized in that, The outer collar includes a non-friction cover (76) that covers the upstream groove wall (52) and the downstream groove wall (58) inside the groove (48).

4. The outer ferrule according to claim 1 or 2, characterized in that, The outer ring also includes at least one third fiber preform (80), each third fiber preform being obtained by three-dimensional weaving of the thread and densified by a matrix, the at least one third fiber preform (80) defining: a base (82) attached from the inside to the cylinder (45) defined by the first fiber preform (64); and a structural gasket span (60) protruding axially downstream beyond the downstream groove wall (58).

5. The outer ferrule according to claim 4, characterized in that, The at least one third fiber preform (80) is dispersed during weaving so as to further define an additional base (84) attached from the outside to the downstream groove wall (58).

6. The outer ferrule according to claim 3, characterized in that, The non-friction covering layer (76) is a fabric or foil.

7. An aircraft turbine engine (1), the aircraft turbine engine comprising an outer ring (23) according to any one of claims 1 to 6.

8. A method for manufacturing an outer ring (23) for an intermediate housing (21) of an aircraft turbine engine, the outer ring being made of a composite material, the outer ring including an annular connecting downstream end (46) forming a radially outwardly opening peripheral groove (48) for receiving complementary connecting parts (50) disposed on one or more nacelle covers (38), and the groove being axially defined by an upstream groove wall (52) and a downstream groove wall (58). Its features are, The method includes the following steps: - A first fiber preform (64) is generated by three-dimensional weaving of the thread, the first fiber preform being used to define the cylindrical body (45) of the outer ring and the structural portion (66) of the downstream groove wall (58) that protrudes radially outward relative to the cylindrical body. - Generate at least one second fiber preform (68), each second fiber preform (68) being obtained by three-dimensional weaving of threads, the at least one second fiber preform being used to define a base (70) and a structural portion (72) of the upstream groove wall (52) that protrudes radially outward relative to the cylinder. - Injection and polymerization of a matrix for densifying the first fiber preform (64); and - Injection and polymerization of a matrix for densifying the at least one second fiber preform (68) such that the base (70) is fixedly and externally attached to the cylinder (45) of the outer collar.

9. The method according to claim 8, characterized in that, The matrix for densifying the first fiber preform (64) and the matrix for densifying the at least one second fiber preform (68) are injected simultaneously via matrix co-injection.

10. The method according to claim 8, characterized in that, First, an injection and polymerization of a matrix for densifying the first fiber preform (64) is performed, and then, in a subsequent curing step, an injection and polymerization of a matrix for densifying the at least one second fiber preform (68) is performed.

11. The method according to any one of claims 8 to 10, characterized in that, The method includes generating a non-frictional coating (76) that covers the upstream groove wall (52) and the downstream groove wall (58) inside the groove (48).

12. The method according to any one of claims 8 to 10, characterized in that, The method further includes: - Generate at least one third fiber preform (80), each third fiber preform (80) obtained by three-dimensional weaving of threads, the at least one third fiber preform serving to define a base (82) and a structural gasket span (60) protruding axially downstream beyond the downstream groove wall; and - Injection and polymerization of a matrix for densifying the at least one third fiber preform (80) such that the base (82) is fixedly and internally attached to the cylinder (45) of the outer collar.

13. The method according to claim 9, characterized in that, The injection of a matrix for densifying the first fiber preform (64) and the injection of a matrix for densifying the at least one second fiber preform (68) are performed simultaneously in a flexible injection tool, a rigid mold matrix transfer tool, or a hybrid tool (90) for flexible injection and rigid mold matrix transfer.

14. The method according to claim 10, characterized in that, First, a matrix for densifying the first fiber preform (64) is injected and polymerized in a rigid mold matrix transfer tool. Then, in a subsequent curing step, a matrix for densifying the at least one second fiber preform (68) is injected and polymerized in a rigid mold matrix transfer tool.

15. The method according to claim 11, characterized in that, The non-friction coating (76) is generated by co-curing during the curing of the first fiber preform (64) and the at least one second fiber preform (68), or the non-friction coating is bonded to the upstream groove wall (52) and the downstream groove wall (58) after the curing.

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