Thrust reverser comprising a simplified-deployment obturator membrane

Abstract

The invention relates to a thrust reverser (30) for an aircraft propulsion unit, comprising a fixed structure (31) equipped with a wall (18) for radially internally delimiting a secondary flow duct (21B), and a mobile structure (29) comprising at least one reverser mobile cowl (33) equipped with a reverser-cowl radially internal wall (52), the mobile structure being movable between a forward direct-thrust position and a retreated reverse-thrust position, the thrust reverser also comprising at least one obturator membrane (58) designed to deflect at least some of the secondary flow towards the cascade vanes (32) when the mobile structure (29) is in the retreated reverse-thrust position. According to the invention, the reverser comprises a mobile frame (60) for deploying the obturator membrane (58), this frame being mounted with the ability to pivot on the mobile structure (29) of the reverser between a retracted position and a position in which it is deployed in the secondary flow duct (21B).

Description

[0001] DESCRIPTION

[0002] TITLE: THRUST REVERSER COMPRISING A SIMPLIFIED DEPLOYMENT SHUT-OFF MEMBRANE

[0003] Technical field

[0004] The invention relates to the field of nacelles and thrust reversers for aircraft propulsion systems, and, more particularly, to thrust reversers equipped with sealing membranes.

[0005] State of the prior art

[0006] Thrust reversers are devices that deflect the airflow passing through the propulsion system forward, in order to shorten landing distances and limit the load on the brakes on the landing gear.

[0007] The grid reversers currently used in the aeronautical sector comprise deflection grids integrated into a fixed or mobile structure of the reverser. The mobile structure of the reverser comprises one or more mobile reverser cowls, and it is mounted so as to be movable in translation relative to the fixed structure between a forward direct thrust position and a rearward thrust reversal position.

[0008] In the rearward thrust reverser position, to divert at least part of the secondary flow towards the grilles, the reverser is usually equipped with shutters, which, when deployed, at least partially close the secondary flow. In a known manner, this forces the air of the secondary flow radially outwards, towards the grilles, which then generate the counter-thrust airflow forward.

[0009] The flaps are generally pivotally mounted on the radially inner wall of the movable reverser cowls, this wall delimiting the secondary flow radially outwards. Thus, recesses are provided in this radially inner wall of the reverser cowls in order to receive the shutter flaps in the retracted position, as adopted in direct jet. However, in direct jet, the presence of the recesses and the flaps is a source of aerodynamic disturbances on the secondary flow. In addition, this presence locally limits the installation of an acoustic panel on the radially inner wall of the reverser cowls.

[0010] To provide a technical solution to these problems, it has been proposed to replace the shutters with one or more sealing membranes. Such a design is known, for example, from document FR 3 076864 Al.

[0011] However, the solutions proposed with sealing membranes remain perfectible, particularly in terms of ease of implementation and reliability of deployment, as well as in terms of preservation of the acoustic surface attached to the secondary vein.

[0012] Statement of the invention

[0013] The invention firstly relates to a thrust reverser for an aircraft propulsion unit, the reverser comprising a fixed structure equipped with a radially internal wall delimiting a secondary flow path of the propulsion unit intended to be traversed by a secondary flow, the reverser also comprising a mobile structure comprising at least one mobile reverser cowl equipped with a radially internal wall of the reverser cowl delimiting the secondary flow path radially outwards, the reverser also comprising at least one deflection grid, the mobile structure being movable in translation relative to the fixed structure along a longitudinal central axis of the reverser, between an advanced direct thrust position and a retracted thrust reversal position,the thrust reverser also comprising at least one blocking membrane designed to divert at least part of the secondary flow towards the deflection grid when the mobile structure is in the retracted thrust reversal position.,

[0014] According to the invention, the reverser also comprises a movable frame for deploying the sealing membrane, a radially internal edge of the membrane being fixed to this movable frame pivotally mounted on the movable structure of the reverser, the movable frame being designed to be moved between a retracted position occupied when the movable structure adopts its forward direct thrust position, and a deployed position in the secondary vein, occupied when the movable structure adopts its retracted thrust reversal position. In addition, in the retracted position of the movable frame, the latter closes an opening through the radially internal wall of the reverser cowl, this opening being used for deploying the sealing membrane in the secondary vein and opening into an internal storage space of the movable reverser cowl, in which the membrane is located when the movable structure adopts its forward direct thrust position.

[0015] Thus, the reverser according to the invention incorporates one or more shutter membranes, which provide improved aerodynamic and acoustic performance to the propulsion unit equipped with such a reverser. Indeed, in direct jet, the fabric is housed in the mobile reverser cowl, which makes it possible to have an external secondary vein practically free of any parasitic geometric singularity for drag, and deleterious for acoustic treatment. Indeed, only the mobile frame for deploying the shutter membrane reconstitutes the secondary vein in direct thrust configuration, the surface area of ​​this frame remaining negligible compared to that encountered in the solutions of the prior art with mobile shutter flaps.

[0016] Furthermore, the design specific to the invention offers simplicity of implementation of the sealing membrane, as well as high reliability of deployment of this membrane, due to the refined deployment kinematics. The mobile frame also makes it possible to reinforce the stability of the membrane, whether during its deployment, or in its deployed configuration when the mobile structure is in the rearward thrust reversal position.

[0017] It is also noted that the proposed design allows the implementation of a membrane extending over a high angular sector. The number of membranes and associated moving frames can thus remain low within the inverter, for a gain in mass.

[0018] The invention preferably provides at least one of the following optional technical characteristics, taken individually or in combination. According to a preferred embodiment of the invention, the inverter comprises at least one mechanical member for controlling the rotation of the movable frame for deploying the sealing membrane.

[0019] Preferably, the mechanical rotation control member comprises a first end articulated on the fixed radially internal delimiting wall of the secondary vein, as well as a second end, opposite the first, articulated on the mobile frame for deploying the sealing membrane, the mechanical control member preferably being a connecting rod. The presence of one or more of these mechanical control members makes it possible, passively, to cause the pivoting of the mobile frame during the axial displacement of the mobile structure between its direct thrust and thrust reversal positions.

[0020] According to another preferred embodiment of the invention, the sealing membrane is inflatable, and the reverser is designed so that the membrane adopts a deflated configuration when it is housed in the internal storage space of the mobile reverser cowl occupying its forward direct thrust position, and an inflated configuration when it is deployed in the secondary vein with the mobile structure in the rearward thrust reversal position.

[0021] Preferably, the passage of the membrane from its deflated configuration to its inflated configuration causes the pivoting of the movable frame from its retracted position to its deployed position in the secondary vein. This makes it possible to avoid the presence of mechanical control members such as the aforementioned connecting rods, and further reduces the overall mass of the inverter as well as the aerodynamic disturbances in the secondary vein.

[0022] Preferably, the reverser is designed so that the pivoting of the movable frame from its retracted position to its deployed position causes, via a transmission system, an axial displacement of the movable reverser cowl from its forward direct thrust position to its retracted thrust reverser position. With such a design where the inflation of the membrane therefore also indirectly causes the axial displacement of the movable reverser cowl, the actuators for actuating the reverser can advantageously be of the single-acting type, and no longer necessarily of the double-acting type as is conventionally the case in the prior art. This results in savings in terms of costs and mass.

[0023] Regardless of the method of construction envisaged, the sealing membrane is preferably equipped with reinforcing hoops. These hoops not only contribute to the mechanical reinforcement of the membrane, but they also give it greater stability.

[0024] Preferably, the movable frame has a general U shape, with the two free ends of the U pivotally mounted on the movable inverter cover.

[0025] Preferably, the radially inner edge of the membrane also has a general U shape fixed along the entire length of the U formed by the movable frame, using a linear connection or a series of adjacent point connections.

[0026] The invention applies equally well to an inversion grid belonging to the fixed structure of the inverter, or to its mobile structure.

[0027] The invention also relates to a nacelle for an aircraft propulsion unit, comprising at least one fan cowl, as well as a thrust reverser as described above.

[0028] Finally, the invention also relates to a propulsion assembly for aircraft, comprising a turbomachine and such a nacelle.

[0029] Other advantages and characteristics of the invention will appear in the detailed non-limiting description below.

[0030] Brief description of the drawings

[0031] The following detailed description refers to the attached drawings in which:

[0032] [Fig. 1] is a schematic half-view in longitudinal section of a propulsion assembly, including a thrust reverser shown in direct thrust configuration;

[0033] [Fig. 2] is a partial perspective view of the reverser equipping the propulsion assembly shown in Figure 1, with the reverser being in the form of a first preferred embodiment of the invention, and shown in the direct thrust configuration; [Fig. 3] is a partial perspective view similar to that of the previous figure, from another viewing angle;

[0034] [Fig. 4] is a partial perspective view similar to that of Fig. 2, with the reverser shown in the thrust reverser configuration;

[0035] [Fig. 5] is a partial perspective view of the inverter shown in Fig. 4, from another angle;

[0036] [Fig. 6] is a partial perspective view similar to that of Fig. 5, with the movable inverter cover removed for clarity;

[0037] [Fig. 7] is a longitudinal half-sectional view, showing the reverser according to an alternative embodiment, and represented in the direct thrust configuration;

[0038] [Fig. 8] is a longitudinal half-sectional view similar to the previous one, with the reverser shown in the thrust reverser configuration;

[0039] [Fig. 9] is a longitudinal half-sectional view, showing the reverser according to another alternative embodiment, and represented in direct thrust configuration;

[0040] [Fig. 10] is a longitudinal half-sectional view similar to the previous one, with the reverser shown in the thrust reverser configuration;

[0041] [Fig. 11] is a schematic view in longitudinal half-section of the reverser in the form of a second preferred embodiment of the invention, and shown in the direct thrust configuration;

[0042] [Fig. 12] is a longitudinal half-sectional view similar to the previous one, with the reverser shown in the thrust reverser configuration;

[0043] [Fig. 13] is a longitudinal half-sectional view, showing the reverser according to an alternative embodiment, and represented in the direct thrust configuration;

[0044] [Fig. 14] is a longitudinal half-sectional view similar to the previous one, with the reverser shown in the thrust reverser configuration; [Fig. 15] is a perspective view showing the inflatable membrane of the alternative shown in Figures 13 and 14, the membrane being in the deflated configuration;

[0045] [Fig. 16] is a perspective view similar to the previous one, with the membrane shown in an inflated configuration;

[0046] [Fig. 17] is a perspective view showing a guide rail system of the mobile reverser cowl on a fixed beam of the propulsion unit allowing the integration of the pneumatic supply necessary for inflating the membrane;

[0047] [Fig. 18] is a schematic top view showing another alternative embodiment for the inverter, with the membrane in the deflated configuration;

[0048] [Fig. 19] is a schematic top view similar to the previous one, with the membrane shown in the inflated configuration;

[0049] [Fig. 20] is a schematic top view showing yet another alternative embodiment for the inverter, this view being similar to that of Fig. 19, and representing the membrane in the inflated configuration;

[0050] [Fig. 21] is a schematic view in longitudinal half-section of the reverser in the form of a third preferred embodiment of the invention, and shown in the direct thrust configuration;

[0051] [Fig. 22] is a longitudinal half-sectional view similar to the previous one, with the reverser shown in the thrust reverser configuration.

[0052] Description of the embodiments

[0053] Figure 1 shows an aircraft propulsion unit 1, having a longitudinal central axis A1.

[0054] Subsequently, the terms "upstream" and "downstream" are defined relative to a general direction SI of gas flow through the propulsion unit 1, along the axis Al when the latter generates direct thrust. These terms "upstream" and "downstream" could respectively be substituted by the terms "front" and "rear", with the same meaning.

[0055] The propulsion unit 1 comprises a turbomachine 2, a nacelle 3 as well as a mast (not shown), intended to connect the propulsion unit 1 to a wing (not shown) of the aircraft.

[0056] The turbomachine 2 is in this example a double-flow, double-spool turbojet 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 turbojet engine 2 is provided with a fan casing 11 connected to the gas generator by structural arms 12.

[0057] The nacelle 3 comprises a front section forming an air inlet 13, a middle section which comprises two fan cowls 14 surrounding the fan casing 11, and a rear section 15.

[0058] In operation, an air flow 20 enters the propulsion unit 1 through the air inlet 13, passes through the fan 5 and then divides into a primary flow 20A and a secondary flow 20B. The primary flow 20A flows in a primary gas circulation vein 21A passing through the gas generator. The secondary flow 20B flows in a secondary vein 21B surrounding the gas generator. The secondary vein 21B is delimited radially inwardly by a fixed internal fairing which envelops 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 rearwardly from the first section 17, so as to form a 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 called wall 18 of radially internal delimitation of secondary vein 21B.

[0059] Radially outwardly, the secondary vein 21B is delimited by the fan casing 11, and, in the configuration of FIG. 1, by one or more movable reverser cowls 33 forming a part of the rear section 15 of the nacelle 3, and which will be described later. More precisely, between the fan casing 11 and the reverser cowls 33, there is provided an outer shroud 40 of an intermediate casing 42, the latter comprising the aforementioned structural arms 12, the radially outer end of which is fixed to this shroud 40. The latter therefore also participates in delimiting the secondary vein 21B radially outwardly, by being located in the downstream axial extension of the fan casing 11.

[0060] The nacelle 3 therefore comprises a thrust reverser 30 (shown only schematically and partially in FIG. 1), centered on the axis A1 and comprising on the one hand a fixed structure 31 secured to 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 which connects it fixedly to the fan casing 11, preferably via a knife-edge flange assembly located downstream of the outer shroud 11. This front frame 46 contains a profiled aerodynamic part called a deflection edge 46B, which guides the flow in an inverted jet.

[0061] In this preferred embodiment, the fixed structure 31 also comprises a plurality of deflection grids 32 arranged adjacent to each other around the axis A1, in a circumferential direction of the reverser 30 and the propulsion assembly 1. Furthermore, the mobile structure 29 comprises the aforementioned mobile reverser cowls 33, for example two cowls 33 each extending over an angular amplitude of approximately 180°. This configuration with two cowls 33 is particularly well suited in the case of a nacelle design in which the cowls / walls 18 are also mounted articulated, the reverser 30 then having a so-called “D-shaped” architecture, known by the English name “D-Duct”. In this architecture, the cowls 18, 33 are connected so as to open / close simultaneously during maintenance operations on the engine.However, other architectures are possible, such as a so-called "C" architecture, known by the Anglo-Saxon name "C-Duct", or a so-called "O" architecture, known by the Anglo-Saxon name "O-.

[0062] Duct ». Each reverser cowl 33 comprises a radially external wall 50 forming an external nacelle aerodynamic surface, as well as a radially internal wall 52 participating in the delimitation of the secondary vein 21B radially outwards. This wall 52 is located in the downstream continuity of the deflection edge 46B, in the direct thrust configuration. The two walls 50, 52 define a housing 54 open axially at the upstream end of the reverser cowl 33, and in which at least a portion of the grids 32 are located in the direct thrust configuration.

[0063] Figure 1 shows the reverser 30 in a forward thrust configuration, called “direct jet”, corresponding to a standard flight configuration. In this configuration, the cowls 33 of the mobile structure 29 are in a closed position, called the advanced thrust or “direct jet” position, in which these reverser cowls 33 are supported on the fixed structure 31, in particular on the deflection edge 46B forming an integral part of the latter. Indeed, in the direct thrust configuration, the upstream end 52A of the radially internal wall 52 of each cowl 33 is in axial support against the deflection edge 46B.

[0064] The mobile structure 29 is thus movable in translation 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 retracted thrust reversal position which will be described later. In the forward direct thrust position of the mobile structure 29, the deflection grids 32 are arranged in the housing 54 of the reverser cowls 33, being isolated from the secondary vein 21B by the radially internal wall 52 of these sliding cowls 33. This wall 52, forming the external wall of the secondary vein, is also called an acoustic internal panel.

[0065] The direct thrust configuration is also shown in Figures 2 and 3, while the rearward thrust reversal position of the mobile structure 29 is shown in Figures 4 to 6, all of these Figures 1 to 6 showing a first preferred embodiment of the present invention. In Figure 4, it is shown that the rearwardly moved internal acoustic panel 52 of the reverser cowls reveals upstream a passage opening 56 of the secondary vein 21B towards the deflection grilles 32. The opening 56 is therefore also delimited upstream by the deflection edge 46B, which flares radially outwards going towards the rear, to delimit an air flow intended to pass through the grilles 32 when the mobile system is in this rearward thrust reversal position.In other words, the deflection edge 46B gradually moves away from the axis A1 from front to rear, to guide / deflect the air towards the grilles 32 in the thrust reversal configuration.

[0066] In order to divert at least part of the secondary flow 20B towards the passage opening 56 defined axially between the diversion edge 46B and the upstream end 52A of the radially internal wall 52 of each cover 33, the inverter 30 comprises one or more closing membranes 58.

[0067] Subsequently, a single membrane 58 will be described for each inverter cover 33. This membrane 58 may extend over a high angular amplitude, for example of the order of 90° to 120°. It is noted that several membranes 58 may follow one another circumferentially along each cover. Similarly, only the cooperation between a membrane 58 and its associated cover 33 will be described below, it being understood that this cooperation is identical or similar for all the covers of the inverter 33.

[0068] The membrane 58 may be made of a material known to those skilled in the art for this type of application. For example, it may be a non-impregnated fabric, for example aramid fibers. The membrane 58 may also be made using a composite material whose matrix is ​​particularly flexible, for example aliphatic polyurethane, which allows use under different temperature conditions, in particular lower temperatures in the case of an aliphatic polyurethane membrane than in the case of a silicone membrane. The matrix gives a low bending recovery capacity and the behavior of the structure obtained is indeed that of a membrane. One of the major properties of this membrane 58 is that it can bend in a perfectly reversible manner (elastic or by fiber sliding) with a very small radius of curvature relative to its surface, and to have a very small thickness, for example of the order of 0.1 to 3 mm.For information purposes, it is observed that this membrane 58 behaves like a boat sail or a parachute / flying wing when it is pressurized.

[0069] One of the particularities of the invention lies in the attachment of the membrane 58 to the inverter 30. To do this, and still with reference to FIGS. 1 to 6, a movable frame 60 is provided for deploying the membrane 58, the frame 60 being pivotally mounted on the radially internal wall 52 of the movable inverter cover 33. Here, the movable frame 60 preferably has a general U shape, with a base 60A extending circumferentially according to a curvature identical or similar to that of the radially internal wall 52. In addition, the two branches 60B of the U have a substantially axial orientation, being here arranged upstream of the base of the U 60A. The two free ends present on the two branches 60B of the U are pivotally mounted on the radially internal wall 52, by means of two pivot connections 62 of coincident axes 64 (FIG. 6).

[0070] A radially internal edge 64A of the membrane 58 also has a general U shape fixed all along the U formed by the movable frame 60, using a linear connection, namely an uninterrupted connection all along these elements 64A, 60 of identical or similar shapes. Alternatively, the linear connection can be replaced by a series of adjacent point connections, preferably not very far apart from each other.

[0071] The radially inner edge 64A of the membrane 58 is therefore fixed to the pivoting mobile frame 60, while a radially outer edge 64B is fixed to a part of the mobile structure 29 of the inverter, here preferably on an inner web 66 of the mobile inverter cover 33. This web 66, arranged radially around the radially inner wall 52, defines with an upstream end thereof an internal space 68 in the thickness of the panel as storage of the membrane 58, in the direct thrust configuration. This internal storage space 68, within the mobile inverter cover 33, is in fact intended to house the membrane 58 folded on itself, for example in an accordion, when the mobile cover 33 adopts its advanced direct thrust position as shown in FIG. 2.Conversely, in the retracted thrust reversal position, the deployed membrane 58 passes through an opening 70 provided in the radially internal wall 52, and is stretched between its two opposite edges 64A, 64B, as seen in FIGS. 4 to 6.

[0072] Reinforcing hoops 72 may be fitted to the membrane 58 to not only reinforce its mechanical strength, but also to improve its stability and control its folding. The hoops 72 follow one another radially and each preferably has a general U shape, following the shape of the membrane 58.

[0073] The aforementioned opening 70 also has a general U-shape, complementary to that of the frame 60. Indeed, the mobile frame 60 is designed to adopt an occupied retracted position when the mobile structure 29 adopts its advanced direct thrust position. In this retracted position, the frame 60 closes the complementary shaped opening 70, by reconstituting the vein, namely by reconstituting the missing part of the radially internal wall 52. The two parts are flush, so as to limit aerodynamic losses on the secondary flow in the direct thrust configuration.

[0074] This opening 70, which serves to deploy the membrane 58 in the secondary vein 21B, therefore opens into the internal storage space 68 of this membrane.

[0075] The pivoting frame 60 can thus be moved from its retracted position which has just been described, to a deployed position in the secondary vein 21B, shown in FIGS. 4 to 6 and occupied when the mobile structure 29 adopts its retracted thrust reversal position. In this deployed position of the mobile frame 60, the latter is pivoted relative to the radially internal wall 52 of the cowl 33 until its base 60A is in contact with or close to the fixed wall 18, so as to block the secondary vein 21B as much as possible.

[0076] To obtain the rotation of the mobile deployment frame 60, the inverter is here equipped with connecting rods 74 arranged in the secondary vein 21B, and of which a first end 74A is articulated on the fixed wall 18 of the secondary vein 21B, and of which a second end 74B opposite the first is articulated on the mobile frame 60, preferably on its base

[0077] 60A. With this design, the presence of the connecting rods 74 makes it possible, passively, to cause the rotation of the mobile frame 60 between its retracted position and its deployed position, during the axial displacement of the mobile structure 29 between its direct thrust position and its thrust reversal position, and vice versa.

[0078] Figures 7 and 8 show an alternative embodiment, in which certain modifications are provided with respect to the first preferred embodiment described above. First of all, the arrangement of the generally U-shaped movable frame 60 is reversed, since the base of the U 60A is located upstream of the branches of the U 60B, and no longer downstream. Another difference lies in the fact that in the direct thrust configuration shown in Figure 7, the membrane 58 is not folded back on itself, but housed in the internal storage space 68 which is here formed by a part of the housing 54 of the movable reverser cowl 33. More precisely, the membrane 58 extends internally along the wall 52. In addition, the radially external edge 64B of the membrane 58 is fixed to a rear frame of grids 76, whereas in the deployed position of the frame shown in Figure 8, this taut membrane does indeed pass through the opening 70.

[0079] When moving the mobile structure to its forward direct thrust position, the upstream end 52A of the radially inner wall 52 presses on the membrane 58, and gradually forces it to relocate into the internal storage space 68.

[0080] Figures 9 and 10 show another alternative embodiment, in which the rotation control rods of the movable frame are no longer necessary. In this alternative, first of all, the membrane 58 is housed in the internal storage space 68 in a manner folded back on itself, like an accordion. This space 68 is moreover presented more in the form of an internal cavity made in the front end of the radially internal wall 52. The opening 70 of this space remains well closed by the base 60A of the pivoting frame 60, when the latter adopts its retracted position of Figure 9. In addition, the radially external edge 64B of the membrane is fixed on a bottom of the cavity 68.

[0081] In this alternative, a cable or strap 78 connects the rear grid frame 76 to the base 60A of the pivoting frame 60, being arranged downstream of the membrane 58. When the mobile structure is moved towards its forward direct thrust position, the cable 78 gradually forces the membrane 58 to fold back on itself and relocate itself in the internal storage space 68. It is the force generated by this cable 78 on the base 60A which allows the rotation of the mobile frame 60 towards its retracted position, preferably in combination with elastic return means associated with the pivot connections 62.

[0082] It is noted that in the first preferred embodiment and its alternatives, the membrane 58 in the deployed state takes the form of a hood, with a main central closure portion extending substantially radially in the secondary vein 21B. The main central closure portion is completed by two lateral flanks opposite one another, in the circumferential direction.

[0083] A second preferred embodiment of the invention is shown in Figures 11 and 12. This second embodiment differs from the first essentially in that the sealing membrane 58 has an inflatable character, that is to say that it defines an interior volume alternately intended to be filled with an inflation fluid, then emptied of this same fluid. In other words, the inflatable sealing membrane 58 is such that it adopts a deflated configuration of small volume when it is housed in the internal storage space 68, and the mobile reverser cowl 33 occupies its forward direct thrust position of Figure 11. In addition, it adopts an inflated configuration of larger volume when it is deployed in the secondary vein 21B, a configuration observed when the mobile structure 29 is in the rearward thrust reversal position of Figure 12.

[0084] Advantageously, the passage of the membrane 58 from its deflated configuration to its inflated configuration causes the pivoting of the movable frame 60 from its retracted position to its deployed position in the secondary vein 21B. It is in fact the deployment by inflation of the membrane 58 which is used to pivot the movable frame 60 to its deployed position, this frame 60 being represented only schematically in FIGS. 11 and 12 but having a design identical or similar to that described in the first embodiment and its alternatives. For pivoting in the other direction, namely from the deployed position of the frame 60 to its retracted position, the suction of the inflation fluid is used, which pushes the membrane 58 to retract inside the storage space 68, and / or elastic return means associated with the pivot connections connecting this frame to the wall 52 of the movable cover 33.

[0085] For the injection of the inflation fluid into the internal volume of the membrane 58, and its extraction, any means deemed appropriate can be used. For example, in this second preferred embodiment, an inflation cylinder 80 is used, a movable part 82 of which is fixed to the movable reverser cover 33, and a fixed part 84 of which is integral with the fixed structure 31 of the reverser. The movable part 82 here constitutes the body of the cylinder, while the movable part 84 is formed by the rod of the cylinder. Thus, the radially external edge 64B of the membrane 58 is open to communicate with one of the chambers of the inflation cylinder 80.In this way, when the movable reverser cowl 33 is moved axially towards its thrust reversal position, the inflation fluid is expelled from this chamber towards the interior volume to inflate it, while when the movable reverser cowl 33 is moved axially towards its direct thrust position, the inflation fluid is sucked into this chamber by extracting itself from the interior volume of the membrane.

[0086] Therefore, inflation and deflation of the membrane 58 occurs automatically upon axial movement of the movable structure 29, achieved with conventional inverter actuating cylinders (not shown in Figures 11 and 12).

[0087] Figures 13 and 14 represent an alternative embodiment, in which the inflation and deflation of the membrane 58 can also be carried out by any means. In this alternative, the singularity comes from the presence of a transmission system which uses the pivoting of the membrane 58 to cause the axial displacement of the mobile reverser cowl 33 from its forward direct thrust position to its rearward thrust reversal position. Indeed, in this alternative, it is always the deployment by inflation of the membrane 58 which generates the pivoting of the mobile frame 60 towards its deployed position in the secondary vein 21B, as shown in Figure 14. The frame 60 further cooperates with the transmission system 86, to cause the axial displacement of the mobile cowl 33 towards its rearward thrust reversal position.To do this, the transmission system 86 comprises the cable or strap 78, a first end 78A of which is connected to the rear grid frame 76, and a second opposite end 78B of which is fixed in the bottom of the interior storage space 68. From the first end 78A, the cable 78, in the direct thrust configuration, first extends upstream until it matches the upstream side of a support pulley 90, connected to the wall 52 possibly using a spring-loaded damping device 92. After the support pulley 90, the cable 78 passes through the inflatable membrane 58 folded into the interior storage space 68, traveling from the radially outer edge 64B to the radially inner edge 64A. Near the latter, the cable 78 is wound around a return pulley 88 fixed to the mobile frame 60, and more precisely to its base 60A.It then travels radially inward to its second end 78B fixed in the interior storage space 68.

[0088] Thus, the pivoting of the mobile frame 60 in the vein 21B has the consequence of moving the return pulley 88 radially towards the inside of this vein, and therefore of pulling on the cable 78 which, by its upstream contact with the support pulley 90, forces the latter as well as the entire cover 33 to move axially downstream. One of the advantages linked to this design lies in the possibility of using reverser actuating cylinders no longer of the conventional double-acting type, but of single-acting to control only the axial movement of the mobile structure 29 upstream, towards its advanced direct thrust position and to brake the mobile structure 29 during opening.

[0089] In this regard, it is noted that in this alternative, the inflatable membrane 58 may have a so-called tube design, shown in Figures 15 and 16. The tubes 58A follow one another in the radial direction, and communicate with each other by fluid communication zones 94, which can be crossed by the cable 78 then helping to fold the membrane 58. In the folded state shown in Figure 15, the tubes 58A are flat and stacked on top of each other, considerably limiting the size of the deflated membrane. As indicated previously, the inflation fluid can be injected into the membrane 58, and extracted therefrom, by any means. For example, with reference to FIG. 17, a conduit 100 may be provided through a guide rail system 102 allowing axial sliding of the movable reverser cowl 33 on a fixed beam 98 of the propulsion assembly.This conduit 100 is then obtained by the hollow nature of one of the elements of the guide rail system 102, through which the inflation fluid can circulate towards, and / or from the inflatable membrane 58.

[0090] Another alternative is shown in Figures 18 and 19, using the guide rail systems 102 to define therethrough conduits 100 for the passage of the inflation fluid, communicating with the open radially outer edge 64B of the inflatable membrane 58. Upstream, these conduits 100 also communicate with any source 108 of inflation fluid.

[0091] In this alternative, the transmission system 86 is also provided with its support pulley 90 and its return pulley, both fixed to the mobile inverter cover 33 shown only schematically, and with its cable 78 cooperating with the aforementioned pulleys. The second end 78B of the cable 78 is directly connected to the base 60A of the mobile frame 60.

[0092] The principles set out above remain applicable for this alternative, in particular the fact of generating the rotation of the mobile frame 60 by the inflation of the membrane, or even the driving downstream of the mobile cover 33 by means of the transmission system 86, the cable 78 of which resting on the pulley 90 is pulled radially inwards due to the rotation of the mobile frame 60 towards its deployed position in the secondary vein.

[0093] In this alternative, the single-acting actuating cylinders 106 have been shown for the upstream movement of the mobile structure 29, these cylinders being for example hydraulic, or even electric.

[0094] A similar alternative is shown in Figure 20, in which the inflation fluid circulation lines 100 are now made through the rods of the actuating cylinders 106 of the reverser. One of the chambers of these cylinders 106 is thus occupied by the inflation fluid used indirectly to move the mobile structure 29 to its rearward thrust reversal position, while the other cylinder chamber is occupied by the actuating fluid allowing the mobile structure 29 to return to its forward direct thrust position. This particular functionalization of the actuating cylinders 106 contributes to reducing the overall size of the reverser.

[0095] To ensure such a reduction in the overall size of the inverter, another solution (not shown) consists of replacing the cable 78 with a hose through which the inflation fluid is able to circulate. This essentially contributes to reducing the overall piping within the inverter, for a gain in mass, cost, and size.

[0096] Finally, it is noted that all of the designs described above are for fixed-gate inverter architectures, but each could be adapted to a moving-gate architecture.

[0097] For example, in the third preferred embodiment of the invention shown in Figures 21 and 22, the first end 78A of the cable 78 is fixed to the fixed structure 31 near or on the deflection edge 46B. The support pulley 90 is fixed to the front frame of grids 76', and the second end 78B of the cable 78 is fixed to the base 60A of the movable frame 60. Here, the inflation of the membrane 58 causes the pivoting of the frame 60, which pulls on the cable 78 radially inward with the consequence that it presses on the pulley 90, which causes the entire movable structure 29, including the grids 32, to move downstream towards the rearward thrust reversal position.

[0098] Various modifications may be made by those skilled in the art to the invention which has just been described, solely by way of non-limiting examples, and the scope of which is defined by the appended claims. For example, the thrust reverser 30 may alternatively have a “C” or “O” architecture. In addition, all the features disclosed above, in the various preferred embodiments and their alternatives, are combinable with each other. Moreover, it is noted that in all the figures which have been described above, the elements which bear the same numerical references correspond to identical or similar elements.

Claims

DEMANDS 1. 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 reverser also comprising at least one deflection grid (32), the movable structure being translationally displaceable relative to the fixed structure along a longitudinal central axis (Al1) of the reverser, between an advanced direct thrust position and a rearward thrust reversal position,the thrust reverser also comprising at least one shut-off membrane (58) designed to deflect at least a portion of the secondary flow towards the deflection grid (32) when the moving structure (29) is in the thrust reverser retracted position, characterized in that it also comprises a movable frame (60) for deploying the shut-off membrane (58), a radially internal edge (64A) of the membrane being fixed to this movable frame (60) pivotally mounted on the moving structure (29) of the reverser, the movable frame being designed to be moved between a retracted position occupied when the moving structure (29) adopts its forward direct thrust position, and a deployed position in the secondary flow (21B), occupied when the moving structure adopts its thrust reverser retracted position, and in that in the retracted position of the movable frame (60), it shuts off an opening (70) through the radially internal wall of the reverser hood (52),this opening (70) serves for the deployment of the sealing membrane (58) in the secondary vein and opens into an internal storage space (68) of the reversing movable cover, in which the membrane (58) is located when the movable structure (29) adopts its forward direct thrust position.

2. Thrust reverser according to claim 1, characterized in that it comprises at least one mechanical element (74) for rotation control of the movable frame (60) for deployment of the sealing membrane (58).

3. Thrust reverser according to claim 2, characterized in that the mechanical rotation control member (74) comprises a first end (74A) articulated on the fixed radially internal delimiting wall (18) of the secondary vein (21B), and a second end (74B), opposite to the first, articulated on the mobile frame (60) for deploying the sealing membrane, the mechanical control member preferably being a connecting rod (74).

4. Thrust reverser according to claim 1, characterized in that the sealing membrane is inflatable, the reverser being designed so that the membrane adopts a deflated configuration when housed in the internal storage space (68) of the reverser movable cover (33) occupying its forward direct thrust position, and an inflated configuration when deployed in the secondary vein (21B) with the movable structure (29) in the rearward thrust reversal position.

5. Thrust reverser according to claim 4, characterized in that it is designed so that the passage of the membrane (58) from its deflated configuration to its inflated configuration causes the pivoting of the movable frame (60) from its retracted position to its deployed position in the secondary vein (21B).

6. Thrust reverser according to claim 5, characterized in that it is designed so that the pivoting of the movable frame (60) from its retracted position to its deployed position causes, via a transmission system (86), an axial displacement of the movable reverser cover (33) from its forward direct thrust position to its rearward thrust reversal position.

7. A thrust reverser according to any one of the preceding claims, characterized in that the movable frame (60) has a general U-shape, with the two free ends of the U pivotally mounted on the movable reverser hood (33).

8. A thrust reverser according to the preceding claim, characterized in that the radially inner edge (64A) of the diaphragm (58) also has a general U-shape fixed along the entire length of the U formed by the movable frame (60) by means of a linear connection or a series of adjacent point connections.

9. A nacelle (3) for an aircraft propulsion system, comprising at least one fan hood (14), and a thrust reverser (30) according to any one of the preceding claims.

10. Propulsion assembly (1) for aircraft, comprising a turbomachine (2) and a nacelle (3) according to the preceding claim.

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