Thrust reverser comprising a deployable flow deflection membrane, and featuring a design that reduces its axial footprint

Abstract

The invention relates to a thrust reverser (30) for an aircraft propulsion system, the reverser comprising a fixed structure (31) and a movable structure (29), and at least one deployable deflection diaphragm (32) designed to deflect at least a portion (20B') of a secondary flow when this diaphragm is in a deployed configuration, the diaphragm comprising an opening contour (112) having a rear portion of the opening contour (112b). According to the invention, the reverser is configured such that the diaphragm (32) moves from a folded configuration to the deployed configuration by rearward displacement of its rear portion of the opening contour (112b), driven by the movable structure (29) during its translational movement from its forward direct thrust position to its rearward thrust reversal position. Figure for the abstract: Fig. 5

Description

Title of the invention: Thrust reverser comprising a deployable membrane OF FLOW DEVIATION, AND PRESENTING A DESIGN REDUCING ITS AXIAL SIZE technical field

[0001] The invention relates to the field of nacelles and thrust reversers for aircraft propulsion systems, and, more particularly, to thrust reversers equipped with deployable membranes to generate flow reversal. Prior art

[0002] Thrust reversers are devices that allow the airflow through the propulsion assembly to be diverted forward, in order to shorten landing distances and limit the stress on the brakes on the landers.

[0003] The grid-type reversers currently used in the aeronautical sector include deflection grids integrated into a fixed or movable structure of the reverser. The movable structure of the reverser comprises one or more movable reverser hoods, and it is mounted to be movable in translation relative to the fixed structure between an advanced position for direct thrust and a rearward position for thrust reversal.

[0004] In the thrust reversing position, to deflect at least part of the secondary flow towards the grilles, the reverser is usually equipped with shutters which, when deployed, at least partially block the secondary flow. In a known manner, this forces the air of the secondary flow radially outwards, towards the grilles, which then generate the forward counter-thrust airflow.

[0005] The flaps are generally pivotally mounted on the radially internal wall of the movable inverter covers, this wall delimiting the secondary stream radially outwards. Thus, recesses are provided in this radially internal wall of the inverter covers to receive the shut-off flaps in the retracted position, as adopted in direct jet operation.

[0006] In the prior art, it has already been proposed to replace the flaps with one or more deployable membranes for obturating the secondary vein. Such a design is, for example, known from document FR 3 076 864 AL

[0007] While the presence of deployable obturation membranes in the secondary vein helps to limit the overall mass of the inverter, this mass remains impacted by the The presence of deflection grilles. These grilles incorporate vanes / blades designed to direct the flow forward to achieve the back-thrust function. Since the radial height of these deflection vanes is limited by the need to house the deflection grilles inside the inverter in a direct jet configuration, it is sometimes necessary to increase the axial length of these grilles to provide a sufficient number of vanes to achieve the required back-thrust performance.

[0008] This increase in the length of the deflection grids generates an increase in the length of several components of the inverter, such as the movable inverter hood(s), actuators, etc. This inevitably leads to a greater mass of the inverter as well as greater drag, synonymous with an increase in specific consumption.

[0009] To address this issue, it has been proposed to replace all or part of the grids with one or more deployable deflection membranes, designed to deflect at least a portion of the secondary flow escaping from the radial extraction opening when this deflection membrane is in a deployed configuration adopted when the moving structure is in the thrust reversing position. Such a design is, for example, described in document FR 3 137 134 A1. The radial deployment of the deflection membrane is automatic. It is created by the air pressure from the secondary flow, after the rearward movement of the moving structure has allowed this air to rush into the membrane, which is held on a frame attached to the fixed structure of the reverser.

[0010] However, there remains a need for optimization of inverters, in particular in order to further reduce their mass and size. Description of the invention

[0011] To at least partially meet the above-mentioned need, the invention first relates to a thrust reverser for an aircraft propulsion system. The reverser comprises a fixed structure equipped with a radially internal boundary wall for a secondary flow of the propulsion system intended to be traversed by a secondary flow. The reverser also comprises a movable structure including at least one movable reverser hood equipped with a radially internal wall for the reverser hood, delimiting the secondary flow radially outwards. The movable structure is translationally displaceable relative to the fixed structure along a longitudinal central axis of the reverser, between an advanced direct thrust position and a rearward thrust reversal position. In the latter position, the movable and fixed structures axially define, on the secondary flow, a radial extraction opening for at least a portion of the flow. secondary, the thrust reverser also comprising at least one deployable deflection membrane designed to deflect at least a portion of the secondary flow escaping from the radial extraction opening, when this deflection membrane is in a deployed configuration adopted when the moving structure is in the thrust reverser rearward position, position in which the deployable deflection membrane defines an air inlet opening in the membrane, delimited by an opening contour comprising a rear portion of the opening contour and two lateral portions of the opening contour, an upstream end of each lateral portion of the opening contour being mounted on a forward membrane support frame, belonging to the fixed structure of the reverser.

[0012] According to the invention, the reverser is configured so that the deployable deflection membrane moves from a folded configuration to the deployed configuration by rearward displacement of its rear portion of opening contour, driven by the moving structure during its translational movement from its forward direct thrust position to its rearward thrust reversal position.

[0013] The invention advantageously provides a simple and reliable solution, further reducing the overall size of the reversing device in the axial direction, which also leads to a decrease in the overall mass. This is due to the smaller axial size of the deflection diaphragm in the direct thrust configuration, since its rear portion of the opening contour is closer to the front diaphragm support frame before being driven rearward to perform the thrust reversal function.

[0014] By reducing the length of the reversing gear installed in the nacelle, drag is also reduced, and specific fuel consumption is lowered. The invention is therefore the result of technological research aimed at significantly improving aircraft performance and, in this respect, contributes to reducing the environmental impact of aircraft (decarbonization).

[0015] The invention preferably provides for at least one of the following optional technical features, taken individually or in combination.

[0016] Preferably, the rear portion of the opening contour of the deployable deflection diaphragm is mounted on a rear diaphragm support frame belonging to the moving structure of the inverter. This mounting can be direct or indirect. It is designed so that the translational movement of the rear support frame ensures, directly or indirectly, the axial deployment of the diaphragm when the inverter is opened.

[0017] Preferably, the two lateral portions of the opening contour are mounted on axially extendable elements, which can have various shapes, some of which will be described below.

[0018] Preferably, each of the two lateral portions of the opening contour is mounted on an axially extendable element, each extendable element being any element among:

[0019] - a telescopic follower arm;

[0020] - a plurality of articulated follower rods;

[0021] - an inverter actuator.

[0022] When the extendable element is a telescopic arm, it may include a first arm end part fixed on the front membrane support frame, and a second arm end part fixed on the rear membrane support frame.

[0023] This telescopic arm may be of conventional shape, or it may be designed to include an additional third central arm section to which the rear portion of the opening contour is attached. The first end section of the arm is designed to be deployed upstream relative to the third central arm section, and the second end section is designed to be deployed downstream relative to the third central arm section. This design advantageously allows the deflection membrane to be axially extracted from the movable hood, and thus brought into radial alignment with the radial extraction opening, in order to properly expose it to the secondary flow.

[0024] According to another possibility, the axially extensible elements can form a one or more scissor-following axial deployment system.

[0025] Preferably, the deployable deflection membrane is a double membrane, comprising two primary membranes arranged axially one behind the other, the inverter being configured so that each of the two primary membranes passes from the folded configuration to the deployed configuration by rearward displacement of its rear portion of opening contour, driven by the moving structure during its translational movement from its forward direct thrust position to its rearward thrust reversal position.

[0026] Preferably, the movable reversing hood is equipped with a radially external wall, defining with the radially internal wall of the reversing hood an axially open housing at the upstream end of the reversing hood, and in which is located at least a part of the deflection diaphragm, in the folded configuration, in the direct thrust configuration of the reversing.

[0027] Preferably, the membrane includes a main deflection portion, having a leading edge corresponding to the rear portion of the opening contour of this deployable deflection membrane.

[0028] Finally, the invention also relates to an aircraft propulsion assembly comprising such a reverser.

[0029] Other advantages and features of the invention will appear in the detailed, non-limiting description below. Brief description of the drawings

[0030] The detailed description that follows refers to the accompanying drawings in which:

[0031] [Fig-1] is a schematic half-view in longitudinal section of an assembly propulsion, comprising a thrust reverser shown in direct thrust configuration; [Fig.2] is a longitudinal half-section view of the reverser equipping the propulsion assembly shown in [Fig.1], with the reverser being in the form of a preferred embodiment of the invention, and shown in direct thrust configuration;

[0032] [Fig.3] is a perspective view of the inverter shown in the previous figure;

[0033] [Fig.4] is a perspective view similar to that of the previous figure, on which has had its movable reversing cover removed;

[0034] [Fig.5] is a longitudinal half-sectional view similar to that of [Fig.2], with the reversing gear shown in a thrust reversal configuration;

[0035] [Fig.6] is a perspective view of the inverter shown in the previous figure;

[0036] [Fig.6A] is a perspective view similar to that of the previous figure, with the deflection membrane presented as an alternative;

[0037] [Fig.7] is a perspective view of one of the deflection membranes in configuration deployed, and showing in more detail the means used to achieve its support;

[0038] [Fig.8] is a schematic top view of the membrane shown in the figure previous;

[0039] [Fig.9] is a perspective view similar to that of [Fig.3], with the inverter represented in the direct thrust configuration, and appearing in the form of another preferred embodiment of the invention;

[0040] [Fig. 10] is a perspective view similar to that of [Fig.9], with the reverser shown in the thrust reversal configuration;

[0041] [Fig. 11] is a perspective view similar to that of [Fig.4], with the axially extensible elements appearing as an alternative;

[0042] [Fig. 12] is a perspective view similar to that of [Fig.4], showing an alternative with a double deflection membrane;

[0043] [Fig. 13] is a top view, with the reverser appearing in the form of another preferred embodiment of the invention, and shown in the direct thrust configuration;

[0044] [Fig. 14] is a top view similar to that of the previous figure, with the reverser shown in an intermediate configuration between the direct thrust configuration and the thrust reversal configuration;

[0045] [Fig. 15] is a top view similar to that of the previous figure, with the reverser shown in the thrust reversing configuration;

[0046] [Fig. 16] is a top view similar to that of [Fig. 13], with the inverter presented in the form of an alternative;

[0047] [Fig. 17] is a top view similar to that of [Fig. 13], with the reverser appearing in the form of another preferred embodiment of the invention, and shown in the direct thrust configuration;

[0048] [Fig. 18] is a top view similar to that of the previous figure, with the reverser shown in the thrust reversing configuration;

[0049] [Fig. 19] is a top view similar to that of [Fig. 13], with the reverser appearing in the form of another preferred embodiment of the invention, and shown in the direct thrust configuration;

[0050] [Fig.20] is a top view similar to that of the previous figure, with the inverter represented according to an alternative. Detailed description of implementation methods

[0051] Figure [Fig.1] shows a propulsion assembly 1 of an aircraft, having a longitudinal central axis Al.

[0052] Hereafter, the terms "upstream" and "downstream" are defined relative to a general SI sense of gas flow through the propulsion assembly 1, along the axis Al when this assembly generates direct thrust. The terms "upstream" and "downstream" could respectively be substituted by the terms "front" and "rear", with the same meaning.

[0053] The propulsion unit 1 comprises a turbomachine 2, a nacelle 3 and a mast (not shown), intended to connect the propulsion unit 1 to a wing (not shown) of the aircraft.

[0054] In this example, the turbomachine 2 is a twin-spool, turbofan engine comprising, from front to rear, a fan 5, a low-pressure compressor 6, a high-pressure compressor 7, a combustion chamber 8, a high-pressure turbine 9, and a low-pressure turbine 10. The compressors 6 and 7, the combustion chamber 8, and the turbines 9 and 10 form a gas generator. The turbofan engine 2 has a fan casing 11 connected to the gas generator by structural arms 12.

[0055] The nacelle 3 comprises a front section forming an air inlet 13, a middle section which includes two blower hoods 14 enveloping the blower housing 11, and a rear section 15.

[0056] During operation, an airflow 20 enters the propulsion assembly 1 through the air inlet 13, passes through the fan 5, and then splits into a primary flow 20A and a secondary flow 20B. The primary flow 20A flows in a primary gas circulation channel 21A through the gas generator. The secondary flow 20B flows in a secondary channel 21B surrounding the gas generator. The secondary channel 21B is radially delimited inwardly by a fixed internal shroud that encloses the gas generator. In this example, the fixed internal fairing comprises a first section 17 belonging to the middle section 14, and a second section 18 extending rearward from the first section 17, so as to form part of the rear section 15. This second section 18 is an integral part of a fixed structure of a thrust reverser which will be described below.This same section will subsequently be referred to as wall 18 of radially internal delimitation of secondary vein 21 B, or internal wall 18.

[0057] Radially outwards, the secondary stream 21B is delimited by the fan housing 11, and, in the configuration of [Fig. 1], by one or more movable reversing gear covers 33 forming part of the rear section 15 of the nacelle 3, which will be described later. More specifically, between the fan housing 11 and the reversing gear covers 33, there is an outer ring 40 of an intermediate housing 42, the latter comprising the aforementioned structural arms 12, the radially external end of which is fixed to this ring 40. This ring therefore also contributes to delimiting the secondary stream 21B radially outwards, being located in the downstream axial extension of the fan housing 11.

[0058] The nacelle 3 therefore comprises a thrust reverser 30 (shown schematically and partially in [Fig. 1]), centered on the axis A1 and comprising, on the one hand, a fixed structure 31 integral with the fan casing 11, and on the other hand, a structure 29 movable relative to the fixed structure 31. The fixed structure 31 comprises, for example, a front frame 46, onto which is attached a streamlined aerodynamic portion called a deflection edge 46B, which guides the flow of the reversed jet. This front frame 46 allows the connection with the fan casing 11, in a known manner.

[0059] The inverter also includes several deployable deflection membranes 32, one of which is schematically shown in a folded / non-deployed configuration in [Fig. 1]. As is known, these deflection membranes 32 replace the more conventional deflection grids, or a combination of grids and membranes 32 can also be provided, for example alternating along the circumferential direction, without departing from the scope of the invention.

[0060] Furthermore, the movable structure 29 comprises the aforementioned movable inverter covers 33, for example, two covers 33 each extending over an angular amplitude of approximately 180°. This configuration with two covers 33 is This design is particularly well-suited to nacelle designs where the cowlings / walls 18 are also hinged, resulting in a D-duct configuration. In this configuration, the cowlings 18 and 33 are connected so that they open and close simultaneously during engine maintenance. However, other configurations are possible, such as a C-duct or an O-duct.

[0061] Each reversing gear cowl 33 comprises a radially external wall 50 forming an external aerodynamic nacelle surface, and a radially internal wall 52 contributing to the outward radial delimitation of the secondary duct 21B. This wall 52 lies in the downstream continuity of the deflection edge 46B in the direct thrust configuration. The two walls 50 and 52 define a housing 54 open axially at the upstream end of the reversing gear cowl 33, and in which at least a portion of the deflection membranes 32 are located in the direct thrust configuration.

[0062] Figure 1 shows the reverser 30 in a forward thrust configuration, known as "direct jet," corresponding to a standard flight configuration. In this configuration, the cowls 33 of the movable structure 29 are in a closed position, known as the forward thrust or "direct jet" position, in which these reverser cowls 33 are supported by the fixed structure 31. Indeed, in the direct thrust configuration, the upstream end 52A of the radially internal wall 52 of each cowl 33 is axially supported against a box section of the forward frame, the deflection edge 46B being arranged radially inwards.

[0063] The movable structure 29 is thus translationally movable relative to the fixed structure 31 along the axis A1 of the reverser, between the forward direct thrust position shown in [Fig. 1], and a rearward thrust reversal position which will be described later. In the forward direct thrust position of the movable structure 29, the deflection membrane(s) 32 in the folded / undeployed configuration are arranged at least partially in the housing 54 of the reverser covers 33, being isolated from the secondary stream 21B by the radially internal wall 52 of these sliding covers 33. This wall 52, forming the external wall of the secondary stream, is also called the internal acoustic panel.

[0064] The deflection membrane 32 can be made of a material known to those skilled in the art for this type of application. For example, it can be an unimpregnated fabric, for example, aramid fibers. The membrane 32 can also be made of a composite material with a particularly flexible matrix, for example, aliphatic polyurethane, which allows its use in Different temperature conditions, notably lower temperatures for an aliphatic polyurethane membrane than for a silicone membrane, are observed. The matrix provides low flexural strength, and the resulting structure behaves like a membrane. One of the key properties of this sealing membrane 32 is its ability to bend in a perfectly reversible manner (elastically or by fiber sliding) with a very small radius of curvature relative to its surface area, and to have a very thin profile, for example, on the order of 0.1 to 3 mm. For informational purposes, it has been observed that this membrane 32 behaves like a sailboat sail or a parachute / flying wing when pressurized.

[0065] The direct thrust configuration is also shown in Figures 2 to 4, while the thrust reversal rearward position of the mobile structure 29 is shown in Figures 5 to 8.

[0066] In [Fig. 5], it is shown that the deflection edge 46B and the upstream end of the movable hood 33 axially define, on the secondary flow 21B, a radial extraction opening 56 for at least a portion 20B' of the secondary flow 20B. This opening 56 of the secondary flow 21B is thus delimited upstream by the deflection edge 46B. Conventionally, this edge flares radially outwards towards the rear, to define an airflow 20B' intended to pass through this opening 56 when the movable structure is in this rearward thrust reversal position. In other words, the deflection edge 46B, here made rigidly, has a shape that gradually moves away from the axis Al from front to back, to guide / deflect the air through the opening 56 and towards the deployable deflection membrane 32, in thrust reversal configuration.Conversely, this opening 56 of the secondary vein 21B is notably delimited downstream by the upstream end 52A of the radially internal part 52 of the hood 33, but also by the upstream end of the radially external wall 50 of this same hood.

[0067] In order to force at least a portion 20B' of the secondary flow 20B towards the opening 56, the diverter 30 includes one or more shutting elements 58. These may be rigid shutting elements, such as flaps, and / or flexible shutting membranes of a deployable nature. In the case of the implementation of secondary flow shutting membranes, the materials used may be identical or similar to those described above for the diverting membranes 32.

[0068] In the preferred embodiment described, the shutter flaps 58 are of conventional design, namely that they are pressed against the wall 52 of the movable hood 33 in the direct thrust configuration, and tilted radially into the secondary vent in the thrust reversal configuration. The kinematics of The movement of the flaps 58 is also known, in particular by means of connecting rods 62 articulated on the internal wall 18.

[0069] As mentioned previously, several deflection membranes 32 are preferentially arranged in succession within the inverter along the circumferential direction. These membranes 32 can all be identical and arranged in the same way, or configured to generate counter-thrust fluxes 20B” in different directions. Thus, some membranes 32 can be arranged to generate counter-thrust forces with a non-zero tangential component.

[0070] For supporting each deflection diaphragm 32, the inverter also includes a rear diaphragm support frame 60 and a front diaphragm support frame 70, each extending in the circumferential direction. One of the features of the invention is that the front diaphragm support frame 70 is integrated into the fixed structure 31 of the inverter, while the rear diaphragm support frame 60 is integrated into the movable structure 29. The front frame 70 is preferably located in or near a front axial end of the opening 56, whereas in the preferred embodiment described, the rear frame 60 connects the two walls 50, 52 of the movable cover 33, delimiting the housing 54 downstream.

[0071] Each deflection membrane 32 is fixed to these two support frames 60, 70, in a manner which will be detailed below, but only for one of these membranes. However, preferably, all the deflection membranes 32 of the inverter are fixed and operate in an identical or analogous manner.

[0072] First, it is noted that in the deployed configuration adopted when the reverser is in its thrust reversal configuration, the deflection diaphragm 32 defines an air inlet opening 110 in the diaphragm at its base. More generally, and with reference to Figures 6 to 8, the deflection diaphragm 32 comprises a main deflection portion 74, a concave active deflection surface 74a of which has a leading edge 76 mounted directly or indirectly on the rear support frame 60. In the case of direct mounting of the leading edge 76 on the rear frame 60, this mounting can be carried out conventionally, using a fitting, an eyelet, a hanger, etc.

[0073] The main deflection portion 74 is such that it provides a homogeneous exit jet direction, substantially perpendicular to the leakage exit section of this main deflection portion 74 of the membrane 32, located at a trailing edge 78 thereof. Furthermore, at this trailing edge 78, it is noted that the membrane 32 can be equipped with fabric reinforcement, in particular to reinforce the parallelism of its radial flanks 80.

[0074] During operation, the secondary flow 20B passes through the secondary vein 21B, and comes into contact, at least in part, with the obturation flaps 58, which force a part 20B' of this flow to pass through the opening 56, and therefore to pass through the air inlet opening 110 of the deflection membrane 32. The flow of the portion of flow 20B' through the extraction opening 56 thus has the effect of pressurizing the concave active deflection surface 74a, and therefore of radially deploying the membrane 32 to its fully deployed configuration, shown in figures 5 to 7.

[0075] The main deflection portion 74, and its concave active inner deflection surface 74a, have the same curved shape which allows the initially radial or substantially radial flow portion 20B' exiting the opening 56 to be progressively straightened, resulting in a forward-directed counter-thrust flow 20B”, for example with a significant component parallel to the AL axis. This direction of the counter-thrust flow 20B”, which can be adapted according to the requirements, is substantially parallel to a tangent to the trailing edge 78 of the main deflection portion 74 and its concave active inner deflection surface 74a. The main portion 74 and its active inner surface 74a can, for example, extend in the form of a circular arc or similar, preferably over an angular extent between 75 and 90°.With this type of membrane 32, a counter-pressure function is preferably sought, therefore the air outlet flow 20B” used for this counter-pressure preferably has a zero tangential component, but such a tangential component could be non-zero, without departing from the scope of the invention.

[0076] The membrane 32 also includes, circumferentially on either side of its main portion of deviation 74, respectively two radial flanks 80 visible on the [Fig.5]. The inner surfaces of these two radial flanks 80 jointly delimit, with the concave active internal deflection surface 74a of the main portion 74, a channel 82 for deflecting forward the part 20B' of the secondary flow escaping from the radial extraction opening 56, to then generate the counter-thrust flow 20B”. With the presence of these radial flanks 80 which run along and are respectively mounted on the two arms 122, the membrane 32 takes on a general shape of a “sail” inflated by the reverse jet, and whose channel 82 which it delimits internally is bent forward, passing from a radial or substantially radial orientation to an axial or substantially axial orientation.To achieve this, each axial flank 80 of the membrane 32 adopts a general triangular, almost flat shape, with one of its sides arched, following the concave shape of the active deflection surface 74a.

[0077] With more specific reference to Figures 7 and 8, it is shown that at a base 108 thereof, there is an air inlet opening 110 in the membrane, delimited by an opening contour 112. This is thus the base 108 of the membrane which forms this opening contour 112, here in general U shape and schematically represented in dotted lines on [Fig.8].

[0078] The membrane's opening contour 110 comprises a rear portion of the opening contour 112b, here straight, or alternatively rounded, corresponding to the aforementioned leading edge 76. Its attachment to the rear frame 60 is achieved either at specific points or linearly along this rear portion of the opening contour 112b. For example, as schematically shown in [Fig. 8], direct attachment to the rear frame 60 can be achieved by means of two attachment points 61 arranged at the circumferential ends of this portion 112b. These two attachment points 61 can also be considered as arranged on the base of the membrane, at the rear ends of the axial flanks 80. Other attachment points can nevertheless be added along the rear portion of the opening contour 112b, without departing from the scope of the invention.

[0079] The membrane opening contour 112 also includes two lateral opening contour portions 112a, here of straight shape. Each lateral portion 112a includes an upstream end which is mounted on the front support frame of the membrane 70, via a fixing point 63. The fixing is preferably direct, and it is also carried out conventionally, using a fitting, an eyelet, a hanger, etc.

[0080] The inverter also includes one or more actuators 120, one of which is shown schematically in Figures 3 and 6. These actuators 120 are designed to generate the translational movement of the movable cover 33 when the inverter is opened. They are circumferentially spaced from each other and, in this preferred embodiment, are also circumferentially spaced from axially extendable follower elements 122 associated with the deflection diaphragm 32. The actuators can be connected downstream of the rear frame 60, on one and / or the other of the two walls 50, 52 of the movable cover 33.

[0081] Indeed, it is provided here that each of the two lateral portions of the opening contour 112a is mounted on an axially extendable element 122, which here takes the form of a telescopic follower arm. This mounting is carried out at the base 108 of the membrane, for example by means of retaining eyelets 124 provided on this base at the level of the lateral portions 112a, and surrounding the telescopic arms 122. According to an alternative shown in [Fig. 6A] and at the bottom of [Fig. 8], the eyelets 124 can be replaced by one or more retaining hems 126, also surrounding the telescopic follower arms 122. The latter can each comprise two or more portions, movable relative to each other in the direction of the arm, which is preferably parallel or substantially parallel to the axis AL

[0082] A first arm end part 122a, corresponding to the front end part of each arm 122, is fixed to the front frame 70, while a second arm end part 122b, corresponding to the rear end part of each arm 122, is fixed to the rear frame 60, or possibly to any other element of the movable hood 33. Also, it is possible, for example, to provide each fixing point 61 of the membrane 32 on the rear end of the telescopic arm 122, and to fix this rear end on the rear frame 60, thus leading to an indirect mounting of the rear portion of the opening contour 112b of the membrane 32, on the rear frame 60.

[0083] One of the features of the invention is that the deflection diaphragm 32 can move from the folded to the deployed configuration by moving its rear portion of the opening contour 112b rearward. To achieve this, during the opening of the reversing gear, the rear portion of the opening contour 112b is driven by the rear frame 60, which itself undergoes a translational movement of the movable cover 33 from its forward direct thrust position to its rearward thrust reversal position. During this movement, the telescopic follower arms 122 also extend, due to their attachment to the rear frame 60.

[0084] Consequently, during the opening of the inverter, the diaphragm 32 gradually unfolds in the axial direction, by displacement of its rear portion of the opening contour 112b. This axial unfolding occurs at the same time as the radial unfolding of the diaphragm 32, the latter resulting from the air rushing into this diaphragm through the opening 110, at the level of its base 108.

[0085] This design advantageously reduces the axial size of the inverter in direct jet configuration, thus decreasing the overall mass and drag.

[0086] When the inverter is closed, the operations described above take place in the opposite direction. The upstream ends of the walls 50, 52 of the moving cover allow the diaphragm 32 to be folded radially, progressively giving it its folded configuration.

[0087] Alternatives and other preferred embodiments will now be described below.

[0088] First, it is noted that a sharing of resources can be provided between the inverter actuators 120 and the axially extendable elements. In the embodiment described above, this would amount to providing that the telescopic arms 122 also fulfill the function of inverter actuators.

[0089] Another preferred embodiment of the invention is shown in Figures 9 and 10.

[0090] In this mode, each telescopic arm 122 further comprises a third central arm part 122c, on which the rear portion of the opening contour is fixed 112b. In other words, this rear portion 112b of the membrane is no longer fixed directly to the rear frame 60, but indirectly via the second end section of the arm 122b. Indeed, the first end section of the arm 122a is designed to be deployed upstream relative to the third central arm section 122c, while the second end section of the arm 122b is designed to be deployed downstream relative to this same third central arm section 122c. Other sections can be added to the telescopic arms 122. But providing different deployment directions for the telescopic sections within each arm also allows, when the inverter is opened, for the rear portion of the opening contour 112b to move axially upstream relative to the rear frame 60, that is, in the opposite direction to the general deployment direction of the arms 122.The advantage then lies in adapting to movable hoods 33 whose rear frame 60 is arranged deeper towards the rear within these hoods. In other words, this allows all or part of the membrane 32 to be extracted from the housing 54, upstream, in order to bring the openings 110, 56 axially to the same level, and thus allow the deflection membrane 32 to function optimally.

[0091] In other words, the second end portion of the arm 122b acts as a connecting follower between the rear support frame 60 and a connecting member of the rear portion of the opening contour 112b of the membrane. This connecting follower 122b is thus mounted to move relative to the connecting member of the rear portion of the opening contour 112b, so as to adopt a retracted position when the movable structure 29 is in its forward direct thrust position, and an axially offset position of the membrane when the movable structure 29 is in its rearward thrust reversal position. In this axially offset position, the connecting member of the rear portion of the opening contour 112b is further axially away from the rear frame 60 than in the forward direct thrust position.

[0092] The connecting follower element could be a separate element of the telescopic arm 122, without departing from the scope of the invention. Similarly, the connecting element of the rear portion of the opening contour 112b corresponds here to the attachment points of this portion 112b on the rear end of the third central arm sections 122c, but it could also be other elements, such as a bar connecting these two sections 122c.

[0093] In this preferred embodiment, another advantage lies in not requiring the actuators 120 to pass through the rear frame 60, as may possibly be the case in the previous embodiment.

[0094] Figure 11 represents an alternative, applicable to all preferred embodiments. In the direct thrust configuration, part of the follower arms The telescopic arms are arranged upstream of the front frame 70, in a so-called blower zone. This allows for a further reduction in the axial length of the reverser.

[0095] Figure 12 represents another alternative, also applicable to all preferred embodiments, in which the membrane 32 can be replaced by a double membrane. This consists of two primary membranes 32a arranged axially one behind the other, and having rear portions of the opening contour 112b attached in different axial positions on their common follower arms 122, or on the rear frame 60. Consequently, each of the two primary membranes 32a is designed to move from the folded configuration to the deployed configuration by rearward movement of its rear portion of the opening contour 112b, driven by the moving structure during its translational movement from its forward direct thrust position to its rearward thrust reversal position.

[0096] In the embodiment shown in Figures 13 to 15, the axially extendable elements are no longer telescopic follower arms, but articulated follower rods 130. For each extendable element, for example, two rods 130 are provided, articulated to each other and also articulated respectively to the front frame 70 and to the rear frame 60. For each extendable element, which is associated with one of the lateral portions of the opening contour 112a, the three articulation points are preferably attached to this lateral portion 112a. This facilitates the axial deployment of the membrane 32 and ensures its stability in the deployed configuration during thrust reversal phases. It should be noted that the articulation points of the rods can, for some of them, also form all or part of the attachment points 61, 63 on the frames 60, 70.

[0097] In this preferred embodiment, the two extendable elements, each formed of two articulated connecting rods, are preferably symmetrical with respect to a fictitious radial and axial median plane of the membrane 32. They also extend symmetrically with respect to this plane. Moreover, although this could be otherwise, the two articulated connecting rods 130 of each extendable element preferably remain in the same plane during axial extension. Here, the two connecting rods 130 of each extendable element are preferably of the same length, but different lengths could be provided.

[0098] In the alternative of [Fig. 16], the two extendable elements are no longer arranged symmetrically with respect to the aforementioned fictitious median plane. For example, the inter-connecting rod joint 132 of one of the two extendable elements can be axially offset from the inter-connecting rod joint 132 of the other of these two extendable elements. This allows for a reduction in size and a greater extension length. Furthermore, these two joints 132 could also be offset from each other. in the radial and / or circumferential direction, the deployment of the extendable elements does not necessarily remain in the same plane.

[0099] In the preferred embodiment of Figures 17 and 18, the axially extendable elements are replaced to form a one- or more-scissor axial deployment system 134. Here, for example, it is a system with two scissors arranged axially in series, each scissor conventionally formed by two connecting rods 130 of the same length, articulated at their midpoints. In this type of deployment system, the scissors are also called "X"s, referring to the shape of the connecting rods articulated in pairs at their midpoints. In addition, each connecting rod 130 is also articulated at its end to another connecting rod 130 of the system 134, via an end joint 136.These end joints 136 are connected to the two lateral portions of the opening contour 112a, and possibly, for some, also connected to the frames 60, 70 in order to form all or part of the aforementioned fixing points 61, 63.

[0100] On one circumferential side of the membrane, the two end joints 136, located at the axial ends of the deployment system 134, are fixed respectively to the frames 60, 70.

[0101] On the other circumferential side of the membrane, the two end joints 136, located at the axial ends of the follower deployment system 134, are respectively housed in two grooves 138, provided on the two frames 60, 70. They can thus slide in these grooves 138 as the axial deployment of the membrane 32 progresses, to adapt to the variation in angle formed by the scissors, and to the evolution of their axial length of the system 134 which results therefrom.

[0102] In the alternative shown in [Fig.19], the two most upstream end joints 136 are both fixed to the front frame 70, while the two most downstream end joints 136 are both housed sliding in one or two grooves 138 of the rear frame 60. An inverted configuration to this is also conceivable.

[0103] Finally, in the alternative of [Fig. 20], the two grooves 138 of the rear frame 60 no longer have a purely circumferential orientation, but an axial component is also present. Preferably, the axial component is such that the two grooves 138 extend upstream as they approach each other.

[0104] Various modifications can be made by a person skilled in the art to the invention just described, solely by way of non-limiting examples, the scope of which is defined by the appended claims. For example, the thrust reverser 30 can alternatively have a "C" or "O" configuration. Furthermore, all the features disclosed above, in the various preferred embodiments and their alternatives, are combinable. Moreover, it is noted that In all the figures described above, elements bearing the same numerical references correspond to identical or similar elements.

Claims

1. Demands Thrust reverser (30) for an aircraft propulsion system, the reverser comprising a fixed structure (31) equipped with a radially internal boundary wall (18) of a secondary flow (21B) of the propulsion system intended to be traversed by a secondary flow (20B), the reverser also comprising a movable structure (29) comprising at least one movable reverser hood (33) equipped with a radially internal reverser hood wall (52) delimiting the secondary flow (21B) radially outwards, the movable structure being translationally movable relative to the fixed structure along a longitudinal central axis (Al) of the reverser, between an advanced direct thrust position, and a rearward thrust reversal position in which the movable structure (29) and the fixed structure (31) axially define between them, on the secondary flow, a radial extraction opening (56) for at least a portion of the secondary flow (20B),the thrust reverser also comprising at least one deployable deflection diaphragm (32) designed to deflect at least a portion (20B') of the secondary flow escaping from the radial extraction opening (56), when this deflection diaphragm is in a deployed configuration adopted when the movable structure (29) is in the thrust reverser rearward position, position in which the deployable deflection diaphragm (32) defines an air inlet opening (110) in the diaphragm, delimited by an opening contour (112) comprising a rear portion of the opening contour (112b) and two lateral portions of the opening contour (112a), an upstream end of each lateral portion of the opening contour (112a) being mounted on a forward diaphragm support frame (70), belonging to the fixed structure (31) of the reverser,characterized in that the reversing device is configured such that the deployable deflection membrane (32) moves from a folded configuration to the deployed configuration by rearward displacement of its rear portion of the opening contour (112b), driven by the movable structure (29) during its translational movement from its forward direct thrust position to its rearward thrust reversal position.

2. Inverter according to claim 1, characterized in that the rear portion of the opening contour (112b) of the deployable deflection membrane (32) is mounted on a rear membrane support frame (60), belonging to the movable structure (29) of the inverter.

3. Inverter according to claim 2, characterized in that the two lateral portions of opening contour (112a) are mounted on axially extendable elements (120, 122, 130, 134).

4. Inverter according to claim 3, characterized in that each of the two lateral portions of opening contour (112a) is mounted on an axially extendable element, each extendable element being any element among: - a telescopic follower arm (122); - a plurality of articulated follower rods (130); - an inverter actuator (120).

5. Inverter according to claim 4, characterized in that when the extendable element is a telescopic arm (122), it comprises a first arm end part (122a) fixed on the front membrane support frame (70), and a second arm end part (122b) fixed on the rear membrane support frame (60).

6. Inverter according to any one of the preceding claims, characterized in that the deployable deflection membrane (32) is a double membrane, comprising two primary membranes (32a) arranged axially one behind the other, the inverter being configured so that each of the two primary membranes (32a) passes from the folded configuration to the deployed configuration by rearward displacement of its rear portion of opening contour (112b), driven by the movable structure (29) during its translational movement from its forward direct thrust position to its rearward thrust reversal position.

7. Inverter according to claim 3, characterized in that the axially extensible elements form a one or more scissor-following axial deployment system (134).

8. Inverter according to any one of the preceding claims, characterized in that the movable inverter cover (33) is equipped with a radially external wall (50), defining with the radially internal wall of the inverter cover (52) a housing (54) open axially at the upstream end of the inverter cover (33), and in which is at least a part of the deflection membrane (32), in the folded configuration, in the direct thrust configuration of the inverter.

9. Inverter according to any one of the preceding claims, characterized in that the membrane (32) comprises a main deflection portion (74), having a leading edge (76) corresponding to the rear portion of the opening contour (112b) of this deployable deflection membrane (32).

10. Aircraft propulsion assembly (1) comprising a reverser (30) according to any one of the preceding claims.

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