Thrust reverser comprising multiple deployable deflection membranes featuring an assembly providing improved performance

Abstract

The invention relates to a thrust reverser for an aircraft propulsion system, comprising a first and a second deployable deflection diaphragm (32), and a diaphragm support frame (66) comprising a first upstream end (66a) and a second downstream end (66b). Each of the first and second deployable deflection diaphragms (32) defines an air inlet opening (110) in the diaphragm, delimited by an opening contour (112) comprising a first and a second lateral portion of the opening contour (112a, 112a'). The first lateral portion of the opening contour (112a) of the first diaphragm and the second lateral portion of the opening contour (112a') of the second diaphragm are engaged on the frame (66) by means of rails (114a, 114a'). Figure for the abstract: Fig. 6

Description

Title of the invention: Thrust reverser comprising several deployable deflection membranes featuring an assembly providing improved performance. 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 the flow reverser. 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 inner wall of the reversing valve covers, this wall delimiting the secondary flow radially outwards. Thus, recesses are provided in this radially inner wall of the reversing valve covers to receive the shut-off flaps in the retracted position, as adopted in direct jet operation. However, in direct jet operation, the presence of the recesses and flaps causes aerodynamic disturbances in the secondary flow. Furthermore, this presence locally limits the placement of an acoustic panel on the radially inner wall of the reversing valve covers.

[0006] To provide a technical solution to these problems, it has been proposed to replace the flaps with one or more deployable vein-closing membranes secondary. Such a design is for example known from document FR 3 076 864 Al.

[0007] While the presence of deployable sealing membranes in the secondary jet helps to limit the overall mass of the inverter, this mass is still affected by the presence of the deflection grids. These grids 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 grids inside the inverter in the direct jet configuration, it is sometimes necessary to increase the axial length of these grids 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 problem, it has been proposed to replace all or part of the grids with one or more deployable deflection membranes, designed to deflect at least part 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 reversal position. However, the solutions provided can be improved, particularly with regard to mass and performance. Description of the invention

[0010] To at least partially solve the problem mentioned above, the invention first relates to a thrust reverser for an aircraft propulsion system, the reverser comprising a fixed structure equipped with a radially internal boundary wall of a secondary flow of the propulsion system intended to be traversed by a secondary flow, the reverser also comprising a movable structure comprising at least one movable reverser hood equipped with a radially internal wall of the reverser hood delimiting the secondary flow radially outwards, the movable structure being translationally movable relative to the fixed structure along a longitudinal central axis of the reverser, between an advanced position of direct thrust, and a rearward position of thrust reversal in which the movable structure and the fixed structure axially define each other, on the secondary flow,a radial extraction opening for at least part of the secondary flow, the thrust reverser also comprising a first and a , second deployable deflection membrane, each 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 rearward position, the first and second membranes being adjacent along a circumferential direction of the inverter, the inverter comprising a membrane support frame including a first upstream end and a second downstream end, and each of the first and second deployable deflection membranes defining an air inlet opening in the membrane, delimited by an opening contour including a first and a second lateral portion of the opening contour,the first lateral portion of the opening contour of the first membrane and the second lateral portion of the opening contour of the second membrane being engaged on said support frame to allow the retention of each of the first and second membranes when this frame is in a nominal operating configuration.

[0011] According to the invention, the support frame comprises a first lateral retaining rail cooperating with the first lateral portion of the opening contour of the first membrane, as well as a second lateral retaining rail distinct from the first rail and cooperating with the second lateral portion of the opening contour of the second membrane.

[0012] The invention is based on the shared use of the means for retaining the deflection membranes, since a single support frame is provided to retain two lateral parts of two adjacent membranes. This shared use results in a significant weight reduction, and in this respect, the invention is the result of technological research aimed at significantly improving aircraft performance. Thus, the invention contributes to reducing the environmental impact of aircraft (decarbonization).

[0013] In addition, the proposed pooling allows the two membranes to be brought circumferentially closer to each other, and thus provides a thrust reversal function with improved performance.

[0014] The rail mounting solution is also advantageous in that it facilitates the mounting and dismounting of the membranes, even independently of one another. This also facilitates maintenance operations requiring the removal of one or more membranes, for example for inspection, repair, or replacement. Maintenance time and costs are thus advantageously reduced.

[0015] It is noted that the principle of the invention is not limited to two adjacent membranes, but it applies to a number of membranes preferably greater than two, or even to all of the deployable reversing membranes present within the inverter.

[0016] The invention preferably provides for at least one of the following optional technical features, taken individually or in combination.

[0017] Preferably, the inverter is designed so that the mounting / dismounting of the first lateral portion of the opening contour of the first membrane, in the first lateral retaining rail, can be carried out by sliding, preferably with the support frame in its nominal operating configuration, and it is designed so that the mounting / dismounting of the second lateral portion of the opening contour of the second membrane, in the second lateral retaining rail, can also be carried out by sliding, also preferably with the support frame in its nominal operating configuration. It is noted that the ability to mount / dismount these lateral portions of the membranes without having to dismantle the support frame provides a significant time saving during implementation.

[0018] Preferably, at least one of the first and second lateral retaining rails has a hollow track. Alternatively, the hollow track could be provided on the lateral portions of the opening contour, without departing from the scope of the invention.

[0019] Preferably, the first upstream end of the support frame includes a front joining element, mounted on a front support frame of the deployable deflection membranes.

[0020] According to a first preferred embodiment of the invention, the second downstream end of the support frame comprises a rear joining element, mounted on a rear support frame of the deployable deflection membranes.

[0021] According to a second preferred embodiment of the invention, the second downstream end of the support frame merges into a rear support frame of the deployable deflection membranes.

[0022] In this second mode, the rear support frame preferably includes a rear retaining rail cooperating with a rear portion of the opening contour of the first membrane, the rear retaining rail being preferably arranged in continuity with the first lateral retaining rail of said support frame, and also preferably arranged in continuity with the second lateral retaining rail of an adjacent support frame.

[0023] Preferably, the first lateral retaining rail of said support frame, the second lateral retaining rail of the adjacent support frame, and the rear retaining rail together form a retaining rail in the general shape of a U. Thanks to this solution, the assembly / disassembly of the deflection membranes is further simplified.

[0024] Regardless of the embodiment envisaged, within the support frame, the first and second retaining rails are preferably spaced apart from each other in a radial direction of the inverter, and they at least partially overlap along the circumferential direction. Such an arrangement allows the two membranes to be brought even closer together in the circumferential direction, resulting in increased thrust reversal performance.

[0025] Preferably, the frame has an evolving cross-section between its two upstream and downstream ends, preferably with an area that increases as it goes downstream.

[0026] The invention also relates to an aircraft propulsion assembly comprising such a thrust reverser.

[0027] Other advantages and features of the invention will become apparent in the detailed, non-limiting description below. Brief description of the drawings

[0028] The detailed description that follows refers to the accompanying drawings in which:

[0029] [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 first preferred embodiment of the invention, and shown in direct thrust configuration;

[0030] [Fig.3] is a longitudinal half-section 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;

[0031] [Fig.4] is a longitudinal half-section view similar to that of the previous figure, with the reverser shown in a thrust reversal configuration;

[0032] [Fig.5] is a perspective view showing two adjacent deflection membranes of the inverter shown in the previous figure, in a deployed configuration of the membranes;

[0033] [Fig.5A] is a side view of one of the two membranes shown in the previous figure;

[0034] [Fig.5B] is a perspective view similar to that of [Fig.5], without the membranes;

[0035] [Fig.6] is a schematic top view of the two deflection membranes shown in the preceding figures, showing in more detail the means used to make their support;

[0036] [Fig.7] is a perspective view of the frame supporting the two membranes shown in the previous figures;

[0037] [Fig.8] is a rear view of the previous figure;

[0038] [Fig.9] is a perspective view similar to [Fig.7], with the support frame of the two membranes made according to an alternative;

[0039] [Fig. 10] is a perspective view schematically illustrating the assembly / disassembly of one of the two membranes;

[0040] [Fig. 11] is a view similar to that of [Fig. 5B], with the inverter appearing in the form of a second preferred embodiment of the invention; and

[0041] [Fig. 12] is an enlarged view of part of the inverter shown in the previous figure. Detailed description of implementation methods

[0042] Figure [Fig.1] shows a propulsion assembly 1 of an aircraft, having a longitudinal central axis Al.

[0043] Hereafter, the terms "upstream" and "downstream" are defined relative to a general SI direction of gas flow through the propulsion unit 1, along the axis Al when this unit generates direct thrust. The terms "upstream" and "downstream" could respectively be substituted by the terms "forward" and "reverse," with the same meaning, and in relation to a direction opposite to the aforementioned SI direction. Furthermore, the figures include a reference frame L, R, and C defining respectively orthogonal longitudinal, radial, and circumferential directions, these directions corresponding to those of the propulsion unit 1, as well as to those of its reversing mechanism.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] During operation, an airflow 20 enters the propulsion assembly 1 through the air inlet 13, passes through the blower 5, and then splits into a primary flow 20A and a secondary flow 20B. The primary flow 20A flows into a primary gas circulation channel 21A passing through the gas generator. The secondary flow 20B flows into a secondary channel 21B surrounding the gas generator. The channel The secondary 21B is radially delimited inwards by a fixed internal fairing that encloses the gas generator. In this example, the fixed internal fairing comprises a first section 17 belonging to the midsection 14, and a second section 18 extending rearwards 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 thrust reverser structure, which will be described below. This same section will subsequently be referred to as the radially internal boundary wall 18 of the secondary 21B.

[0048] 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 hoods 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 hoods 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.

[0049] The nacelle 3 therefore includes a thrust reverser 30 (shown schematically and partially in [Fig. 1]), centered on the axis Al and comprising on the one hand a fixed structure 31 attached to the fan casing 11, and on the other hand a structure 29 movable relative to the fixed structure 31. The fixed structure 31 includes for example a front frame 46 which connects it fixedly to the fan casing 11, preferably via a knife flange assembly located downstream of the outer ferrule 11. This front frame 46 contains a profiled aerodynamic part called a deflection edge 46B, which guides the flow in reverse jet.

[0050] In this first preferred embodiment, the fixed structure 31 also includes several deployable deflection membranes 32, one of which is schematically represented in a non-deployed configuration in [Fig.1].

[0051] Furthermore, the mobile structure 29 comprises the aforementioned movable reversing unit hoods 33, for example, two hoods 33 each extending over an angular range of approximately 180°. This configuration with two hoods 33 is particularly well suited to a nacelle design in which the hoods / walls 18 are also hinged, the reversing unit 30 then having a so-called "D-duct" architecture. In this architecture, the hoods 18 and 33 are connected so as to open / close simultaneously during engine maintenance operations. However, other architectures are possible, such as a so-called "C-duct" architecture. under the Anglo-Saxon name "C-Duct", or an architecture called "in O", known under the Anglo-Saxon name "O-Duct".

[0052] 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 diaphragms 32 are located in the direct thrust configuration.

[0053] Figure 1 shows the reversing gear 30 in a forward thrust configuration, known as the "direct jet" configuration, corresponding to a standard flight configuration. In this configuration, the cowlings 33 of the movable structure 29 are in a closed position, known as the forward thrust or "direct jet" position, in which these reversing gear cowlings 33 bear against the fixed structure 31, in particular against the deflection edge 46B, which is an integral part of the latter. Indeed, in the direct thrust configuration, the upstream end 52a of the radially internal wall 52 of each cowling 33 bears axially against the deflection edge 46B.

[0054] 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 membranes 32 in the folded / non-deployed configuration are arranged 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.

[0055] The direct thrust configuration is also shown in [Fig. 2], while the thrust reversal rearward position of the moving structure 29 is shown in [Fig. 4]. [Fig. 3] shows the reverser in an intermediate position between the positions of Figures 2 and 4. Figures 1 to 8 together show the first preferred embodiment of the present invention.

[0056] In [Fig. 4], it is shown that the deflection edge 46B and the upstream end of the movable hood 33 axially delimit, on the secondary vein 21B, a radial extraction opening 56 for at least a portion 20B' of the secondary flow 20B. This opening 56 of the secondary vein 21B is therefore delimited upstream by the deflection edge 46B, which, conventionally, flares radially outwards towards the rear, to delimit an airflow 20B' intended for air passes through this opening 56 when the moving system is in this rearward thrust reversal position. In other words, the deflection edge 46B, here rigidly constructed, gradually moves away from the axis A1 from front to back, to guide / deflect the air through the opening 56 and towards the deployable deflection membrane 32, in the thrust reversal configuration. Conversely, this opening 56 of the secondary vent 21B is delimited downstream by the upstream end 52a of the radially internal part 52 of the hood 33, and also by the upstream end of the radially external wall 50 of the same hood.

[0057] In order to force at least a portion 20B' of the secondary flow 20B towards the opening 56, the inverter 30 comprises one or more shut-off membranes 58. Hereafter, a single membrane 58 will be described, the assembly of which, for example, has an angular amplitude identical or similar to that of the assembly of deflection membranes 32, which will be described later, and which lies in the same axial and radial plane of the propulsion assembly. Thus, several circumferentially adjacent membranes 58 may be provided within the secondary flow 21B. However, the angular extent of the shut-off membrane 58 may be greater than that of the deflection membrane 32, without departing from the scope of the invention.

[0058] The membrane 58 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, such as aramid fibers. The membrane 58 can also be made of a composite material with a particularly flexible matrix, such as aliphatic polyurethane, which allows its use under different temperature conditions, notably lower temperatures for an aliphatic polyurethane membrane than for a silicone membrane. The matrix provides low flexural strength, and the resulting structure behaves like a membrane.One of the major properties of this sealing membrane 58 is its ability to fold 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 small thickness, for example, on the order of 0.1 to 3 mm. For information purposes, it has been observed that this membrane 58 behaves like a boat sail or a parachute / flying wing when it is pressurized.

[0059] A first end 58a of the sealing membrane 58 is fixed to a rear support frame 60 belonging to the fixed structure 31 and extending along the circumferential direction C, this frame being located in or near a rear axial end of the opening 56 and serving to support the membranes 32. Similarly, a front support frame 70 is provided, also belonging to the fixed structure 31 and extending along the circumferential direction C, this front frame 70 located in or near a front axial end of the opening 56 and serving to support the membranes 32. Each of the front and rear frames 70, 60 can be made in one piece, or in a segmented manner, in particular along the circumferential direction C.

[0060] In addition, a second end 58b of the sealing membrane 58, opposite the first membrane end 58a, is fixed to the wall 18. It is noted that the first end 58a can be fixed to the rear of the rear support frame 60 as shown in the figures, or to the front of the same support.

[0061] For this purpose, connecting rods 62 can be used, the first end of each of which is mounted on the wall 18, preferably via a pivot or ball joint 64. This joint 64 can be made using a fitting fixed to the fixed wall 18 and cooperating with the first end of connecting rod 62a.

[0062] The connecting rods 62 are spaced circumferentially from each other within the secondary vein 21 B, and their number can vary.

[0063] Each connecting rod 62 is designed to move from a radially projecting position in the secondary channel 21B, shown in [Fig. 2] and adopted when the moving structure 29 occupies its forward direct thrust position, to a downstream folded-down position, shown in [Fig. 4] and adopted when the moving structure 29 occupies its rearward thrust reversal position. In the projecting position, each connecting rod 62 can adopt a radial or substantially radial orientation with respect to the axis A1, while in the folded-down position, each connecting rod can adopt an axial or substantially axial orientation.

[0064] The second end of each connecting rod 62, opposite the first end, can be connected directly to the second end 58b of the membrane 58. However, other preferred solutions are considered, such as those aimed at integrating cables and / or reinforcing straps within the means of attaching the membrane 58 to its associated elements 18, 60.

[0065] As can be seen in Figures 3 and 4, when the movable structure 29 moves and reaches its rearward thrust reversal position at the end of this movement, the sealing membrane 58 is partially supported against the upstream end 52a of the radially internal wall 52 of the reversing hood, thus corresponding to the acoustic panel. More precisely, during the rearward movement of the movable structure 29, the membrane 58 slides on this upstream end 52a of the radially internal wall 52.

[0066] In the retracted thrust reversal position of [Fig. 4], the membrane 58 is therefore axially supported downstream against the upstream end 52a. It should be noted that, depending on the extent of the axial stroke of the inverter, the membrane 58 may no longer be in contact with the internal acoustic panel 52 in the fully deployed position of the inverter, where Hood 33 is in its rearmost position. The contact option corresponds to a minimized stroke of the inverter, while the non-contact option generally corresponds to a smoother membrane shape in reverse jet, therefore more efficient from an aerodynamic point of view.

[0067] Thus, the part of the membrane 58 which is located radially outwards with respect to its bearing area on the wall 52 closes a part of the upstream axial opening of the housing 54, while the other part located radially inwards closes at least a part of the secondary vein 21B, thereby deviating at least a part 20B' of the secondary flow 20B towards the opening 56 in the direction of the deployable deflection membrane 32.

[0068] It is noted that the membranes 58 could be replaced by more conventional sealing flaps, or be provided in combination with these flaps.

[0069] The material used to make the membranes 32 is any one of those already mentioned above, for making the sealing membrane 58.

[0070] As mentioned previously, in this preferred embodiment, several deflection membranes 32 are arranged circumferentially within the inverter. These membranes 32 can all be identical and arranged in the same way, or configured to generate counter-thrust flows from different directions, without departing from the scope of the invention.

[0071] Each deployable deflection membrane 32 is mounted on the two support frames 60, 70, by means which are specific to the present invention and which will now be detailed with reference to figures 5 to 8.

[0072] These figures will describe the arrangement of two adjacent membranes 32 along the circumferential direction C, namely two membranes 32 directly consecutive along this same direction. However, the principle of the invention, which will be explained below, applies similarly to a number of adjacent membranes greater than two, or even to all of the deflection membranes 32 of the inverter.

[0073] For mounting these two membranes 32, support frames 66 are provided, spaced circumferentially from one another. Each support frame 66 preferably extends along the longitudinal direction L, or is inclined with respect to it. It comprises a first upstream end 66a, having a front joining element 67 mounted on the front support frame 70. Furthermore, in this first preferred embodiment of the invention, it comprises a second downstream end 66b, having a rear joining element 69, mounted on the rear support frame 60.

[0074] Here, each armature 66 is in the shape of a connecting rod fixed at its opposite ends to the frames 70, 60, respectively via the connecting elements 67, 69, forming preferably reversible / removable mechanical connections, for example connections Ball joints. For example, the front connecting member 67 takes the form of a ball joint fixed to a bracket 71 of the front frame 70, with a shaft 73 passing through the assembly. As for the rear connecting member 69, it comprises, for example, a ring surrounding and clamping the rear frame 60, for example, with a circular cross-section.

[0075] One of the features of the invention, which will be described below, lies in the shared use of the support brackets 66 for mounting the diaphragms 32 within the inverter. Indeed, each bracket 66 is designed to retain two adjacent diaphragms 32. In other words, at the circumferential transition between two deflection diaphragms 32, only one connecting rod-shaped retaining bracket 66 is provided, and not two separate and adjacent brackets as in more conventional prior art solutions.

[0076] Each deflection membrane 32 comprises a main deflection portion 74, of which a concave deflection active surface 74a has a leading edge 76 fixed to the rear support frame 60, preferably using a hanger or loops 77 formed by the membrane, and surrounding the rear frame.

[0077] Figures 5, 5A and 5B show that the first mechanical link 67 is fixed to a portion of the frame 70 which acts as a solid extension of the deflection edge 46B, with a streamlined shape that is aerodynamically continuous with the latter. This bypass zone with a small radius of curvature makes it possible to obtain an outlet jet with a homogeneous direction substantially perpendicular to the leakage outlet section of the main deflection portion 74 of the membrane 32, located at a trailing edge 78 thereof.

[0078] Furthermore, at the level of this trailing edge 78, it is noted that the membrane 32 can be equipped with a fabric reinforcement 83 schematically shown in [Fig.5A], in particular to reinforce the parallelism of its radial sides 80.

[0079] In operation, the secondary flow 20B passes through the secondary vein 21B, and comes into contact at least in part with the deployed sealing membrane 58, which forces a part 20B' of this flow to pass through the opening 56, therefore through the opening defined by the frames 70, 60 and the armatures 66. The flow of the part of the flow 20B' through the extraction opening 56 thus has the effect of pressurizing the concave active deflection surface 74a, and therefore of deploying the deflection membrane 32 to its fully deployed configuration shown in figures 4 and 5 and 5A.

[0080] 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' to be progressively straightened upon exiting the opening 56, resulting in a forward-oriented counter-thrust flow 20B”, for example with a significant component parallel to the A1 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 range between 75 and 90°. With this type of membrane 32, a counter-thrust function is preferably sought, in which the air outlet flow 20B” used for this counter-thrust preferably has a zero tangential component. Only an axial component, and possibly a radial component, are present.

[0081] Each membrane 32 also includes, circumferentially on either side of its main deflection portion 74, respectively two radial flanks 80. The inner surface of these two radial flanks 80 jointly delimit, with the concave active inner deflection surface 74a of the main portion 74, a forward deflection channel 82 of the part 20B' of the secondary flow escaping from the radial extraction opening 56, to subsequently generate the counter-thrust flow 20B”. With the presence of these radial flanks 80 which run along and are respectively mounted on the two frames 66, the membrane 32 takes on a general “hood” shape, the channel 82 of which it internally delimits is bent forward, passing from a radial or substantially radial orientation to an axial or substantially axial orientation.To achieve this, each radial 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.

[0082] At a base 108 of each membrane, there is an air inlet opening 110 in the membrane, delimited by an opening contour 112. It is thus the base 108 of the membrane which forms this opening contour 112, here in the general shape of a U and schematically represented in dotted lines on the [Fig.6].

[0083] The membrane opening contour includes a rear portion of the opening contour 112b, here straight in shape, connected to loops 77 for attachment to the rear support frame 60. Alternatively, the rear portion of the opening contour 112b could be rounded, with the hollow of the arc facing forward. Alternatively, regardless of its shape, this rear portion of the opening contour 112b can be mounted on the rear ends of the support frames 66, thus without a direct connection to the rear frame 60.

[0084] The opening contour 112 of the membrane also includes two lateral opening contour portions 112a, 112a', here straight in shape, following the two frames 66 on which these portions 112a, 112a' are respectively engaged. Indeed, the engagement between the lateral opening contour portions 112a, 112a', and the supports 66, is intended to ensure the retention of the membranes 32, when these support supports 66 are in a nominal operating configuration, in which the two mechanical links 67, 69 of each support 66 are in a mounted state, on their respective frames 70, 60.

[0085] As mentioned above, each of the first and second deployable deflection membranes 32, shown in Figures 5 and 6, defines an air inlet opening 110 in the membrane, delimited by the opening contour 112 comprising a first 112a and a second lateral portion of the opening contour 112a'. For these two membranes 32, the first lateral portion of the opening contour 112a of the first membrane, and the second lateral portion of the opening contour 112a' of the second membrane, are engaged on the same support frame 66. Consequently, this connecting rod-shaped frame 66 allows each of the first and second membranes 32 to be retained when this frame is in its nominal operating configuration, shown in the figures.

[0086] To ensure this retention, this support frame 66 includes a first lateral retention rail 114a, which preferably extends along the entire length of the frame 66 between its two connecting members 67, 69, parallel to the longitudinal direction of this frame. This first rail 114a has a hollow track, which receives the first lateral portion of the opening contour 112a of the first membrane 32, this thickened portion 112a preferably taking the form of a rod, or a rope inserted into the hollow track of the first rail 114a. Similarly, this same support frame 66 includes a second lateral retention rail 114a', separate from the first and which preferably also extends along the entire length of the frame 66 between its two connecting members 67, 69, parallel or substantially parallel to the first rail 114a.The second rail 114a' has a hollow track, which receives the second lateral portion of the opening contour 112a' of the second membrane 32, this thickened portion 112a' also preferably taking the form of a rod or a rope, inserted into the hollow track of the second rail 114a'. .

[0087] Preferably, several of the support frames 66 have such a design, and even more preferably all those which are at the circumferential interface between two adjacent deflection membranes 32.

[0088] In Figures 5 and 5B, it is shown that a front end of each lateral portion of the opening contour 112a, 112a' of each membrane may have a load-bearing eyelet 116. This eyelet is either mounted on the support rod 66, or, as shown in these figures, mounted on the front support frame 70, preferably via the same clevis-shaped fitting 71 as that used to attach the front connecting member 67 to this frame 70. The eyelet 116, through which passes a shaft 79 carried by The fitting 71 essentially allows the absorption of axial forces exerted on the membrane 32.

[0089] Figures 7 and 8 show that in this first preferred embodiment of the invention, the two rails 114a, 114a' are adjacent along the circumferential direction C and arranged substantially at the same radial level, opening radially outwards. According to an alternative shown in [Fig. 9], the first and second retaining rails 114a, 114a' are spaced apart along the radial direction R, so as to be able to overlap at least partially along the circumferential direction C. With this solution, the two adjacent membranes 32 can be brought closer together along this same direction C, for improved inverter performance.

[0090] Thanks to the invention and the pooling of its means of retaining the deflection membranes, the overall mass of the inverter can advantageously be reduced, and the membranes brought closer together.

[0091] Furthermore, the retaining rail solution facilitates the mounting and dismounting of the membranes 32, even independently of one another. As shown schematically in [Fig. 10], this mounting / dismounting can be carried out by simply sliding the membrane ropes in their respective rails from one end of these rails, for example, from the front end. Preferably, this mounting / dismounting can be carried out with the support frames 66 maintained in their nominal operating configuration, i.e., without dismantling the connecting elements 67, 69, which remain fixed to the support frames 70, 60. Such dismantling of one or both of these elements 67, 69 may nevertheless be required, without departing from the scope of the invention. In addition, it is noted that once the insertion into the rail is complete, the rail can be sealed with a removable plug.Alternatively, one or both opposite ends of each rail can be left open, since, due to the air pressure to which each membrane is subjected during operation, the risk of these membranes accidentally detaching from the rails remains nil.

[0092] Figures 11 and 12 illustrate a second preferred embodiment of the invention, in which the second downstream end 66b of the support frame 66 is integrated into the rear support frame 60 of the deployable deflection membranes 32. This second downstream end 66b can be formed in one piece with this portion of the rear frame 60, or attached to it, preferably ensuring continuity of material. In this regard, it is noted that in this preferred embodiment, the support frame 66, preferably beam-shaped, has a cross-section that changes between its two upstream and downstream ends 66a, 66b, with a surface area that increases downstream. This widening of the frame 66 along the circumferential direction C continues at the level of the support frame 60. which flares out considerably, always moving downstream. This design aims to obtain frame sections 60a in the general shape of a U open upstream, which connect the reinforcements 66 at their downstream ends 66b. Each of these frame sections 60a can be made using two half-sections fixed one on top of the other and arranged in succession along the circumferential direction C, each made in one piece with two directly consecutive support reinforcements 66.

[0093] The advantage of such a design lies in the fact that each portion of the rear frame 60a, generally U-shaped, can also integrate a membrane retaining rail.

[0094] Indeed, it is preferably provided that the rear support frame 60 has, at one of its portions 60a between two frames 66, a rear retaining rail 114b cooperating with the rear portion of the opening contour 112b of the first membrane 32. To do this, the rear rail 114b has a hollow track, which receives the rear portion of the opening contour 112b of the first membrane 32. This thickened portion 112b also preferably takes the form of a rod or a rope, inserted into the hollow track of the rear rail 114b.

[0095] In this way, the rear rail 114b is arranged in the downstream continuity of the first lateral retaining rail 114a of one of the two support frames 66 of the first membrane 32, and also arranged, at its other end, in the downstream continuity of the second lateral retaining rail 114a' of the other of these two support frames 66. An identical or similar arrangement is provided for the second membrane 32, and for all or part of the other deflection membranes 32 of the inverter.

[0096] In this arrangement, the first lateral retaining rail 114a of the first support frame 66, the second lateral retaining rail 114a' of the adjacent support frame 66, and the rear retaining rail 114b between these two frames, together form a retaining rail in the general shape of a U. This single rail is preferably continuous between the two upstream ends 66a of the two support frames 66, and therefore cooperates with a complementary shaped bead / rope, corresponding to the assembly formed by the three opening contour portions 112a, 112a' and 112b of each deflection membrane 32. These three portions 112a, 112a' and 112b thus form a preferably continuous bead / rope, in the shape of a U when inserted in the single rail.

[0097] It is noted that all the retaining rails 114a, 114a', 114b described above, in the various preferred embodiments, can be made in one piece with the elements 66, 60 that support them. Alternatively, they can be attached to these same elements, without departing from the scope of the invention.

[0098] Various modifications can be made by a person skilled in the art to the invention just described, solely by way of non-limiting examples, and of which the The scope is defined by the attached claims. For example, the thrust reverser 30 can alternatively have a "C" or "O" shaped architecture. Furthermore, the membranes specific to the invention can coexist with conventional grids within the reverser. Moreover, all the features disclosed above, in the various preferred embodiments and their alternatives, are combinable. It should also be noted that in all the figures described above, elements bearing the same numerical references correspond to identical or similar elements. Finally, it should be noted that the closure of the secondary channel is preferably achieved by a flexible structure, such as a membrane / textile, and / or by a rigid structure, such as conventional flaps of the prior art.

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 a first and a second deployable deflection membrane (32), each designed to deflect at least a portion (20B') of the secondary flow escaping from the radial extraction opening (56), when this deflection membrane is in a deployed configuration adopted when the movable structure (29) is in the thrust reverser rearward position, the first and second membranes (32) being adjacent along a circumferential direction (C) of the reverser, the reverser comprising a membrane support frame (66) comprising a first upstream end (66a) and a second downstream end (66b), each of the first and second deployable deflection membranes (32) defining an air inlet opening (110) in the membrane, delimited by an opening contour (112) comprising a first and a second lateral portion of the opening contour (112a, 112a'),the first lateral portion of the opening contour (112a) of the first membrane and the second lateral portion of the opening contour (112a') of the second membrane being engaged on said support armature (66) to allow the retention of each of the first and second membranes (32) when this armature is in a nominal operating configuration, characterized in that the support frame (66) comprises a first lateral retaining rail (114a) cooperating with the first lateral portion of the opening contour (112a) of the first membrane (32), and a second lateral retaining rail (114a') distinct from the first rail and cooperating with the second lateral portion of the opening contour (112a') of the second membrane (32).

2. Inverter according to claim 1, characterized in that it is designed so that the mounting / dismounting of the first lateral portion of the opening contour (112a) of the first membrane (32), in the first lateral retaining rail (114a), can be carried out by sliding, preferably with the support armature (66) in its nominal operating configuration, and in that it is designed so that the mounting / dismounting of the second lateral portion of the opening contour (112a') of the second membrane (32), in the second lateral retaining rail (114a'), can be carried out by sliding, preferably with the support armature (66) in its nominal operating configuration.

3. Inverter according to claim 1 or 2, characterized in that at least one of the first and second lateral retaining rails (114a, 114a') has a hollow track.

4. Inverter according to any one of the preceding claims, characterized in that the first upstream end (66a) of the support frame (66) comprises a front joining member (67), mounted on a front support frame (70) of the deployable deflection membranes (32).

5. Inverter according to any one of the preceding claims, characterized in that the second downstream end (66b) of the support frame (66) comprises a rear connecting member (69), mounted on a rear support frame (60) of the deployable deflection membranes (32).

6. Inverter according to any one of claims 1 to 4, characterized in that the second downstream end (66b) of the support armature (66) merges into a rear support frame (60) of the deployable deflection membranes (32).

7. Inverter according to claim 6, characterized in that the rear support frame (60) comprises a rear retaining rail (114b) cooperating with a rear portion of the opening contour (112b) of the first membrane, the rear retaining rail (114b) being preferably arranged in continuity with the first lateral retaining rail (114a) of said support frame (66), and also preferably arranged in continuity with the second lateral retaining rail (114a') of an adjacent support frame (66).

8. Inverter according to claim 7, characterized in that the first lateral retaining rail (114a) of said support frame (66), the second lateral retaining rail (114a') of the adjacent support frame (66), and the rear retaining rail (114b) together form a retaining rail in the general shape of a U.

9. Inverter according to any one of the preceding claims, characterized in that within the support frame (66), the first and second retaining rails (114a, 114a') are spaced apart from each other in a radial direction (R) of the inverter, and they overlap at least partially in the circumferential direction (C).

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

Images