Thrust reverser comprising a movable structure with a hybrid o and c architecture
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-02-06
- Publication Date
- 2026-08-13
Smart Images
Figure FR2026050115_13082026_PF_FP_ABST
Abstract
Description
[0001] Thrust reverser comprising a mobile structure with a hybrid O and C architecture
[0002] technical field
[0003] The invention relates to the field of nacelles and thrust reversers for aircraft propulsion systems, and, more particularly, to the design of the moving structure of such reversers.
[0004] Prior art
[0005] Thrust reversers are devices that divert the airflow through the propulsion system forward, in order to shorten landing distances and limit the stress on the brakes on the landing gear.
[0006] The grid-type reversers currently used in the aeronautical sector include deflection grids integrated into a fixed or movable reverser structure. The movable reverser structure comprises one or more movable reverser hoods and is mounted to move translationally relative to the fixed structure between a forward direct thrust position and a rearward thrust reverser position. In the rearward thrust reverser position, to deflect at least some of the secondary flow toward the grids, the reverser is usually equipped with shutters, which, when deployed, at least partially block the secondary flow. In a known manner, this forces the secondary flow air radially outward toward the grids, which then generate the forward counter-thrust airflow.From prior art, it is also known to replace the flaps with one or more deployable membranes for obturating the secondary vein. Such a design is known, for example, from document FR 3076864 Al.
[0007] The reversing gear's moving structure can be built according to various known designs. Among these is the so-called "O" design, also known as the "O-duct." This O-duct design incorporates an external radial boundary structure for a secondary thrust stream of the propulsion system, extending over a large angular sector, typically greater than 240°, and preferably greater than 270°. For reference, the remaining angular sector required to achieve a complete 360° annular structure corresponds to the space available for the mounting mast and the attachment of this annular O-duct structure to the mast.
[0008] Therefore, the term annular O-shaped structure is commonly accepted, even if the O is not circumferentially complete.
[0009] The O-shaped architecture is known for offering good aerodynamic performance in direct jets, since the secondary flow remains only slightly disturbed by the nearly complete annular structure that surrounds it. Furthermore, it allows for the installation of deflection grids and / or deflection membranes over a large angular sector, which enhances thrust reversal performance.
[0010] However, the O-shaped architecture can complicate engine access for maintenance operations. Indeed, a long rearward travel distance is required within the annular structure to access the engine, along with onboard means to facilitate this movement.
[0011] Among the various known engine architectures, there is also the so-called "C-duct" architecture. In this C-duct architecture, the annular structure of the O-duct architecture is replaced by two C-shaped cowlings, each hinged to the pylon. These two external movable cowlings are conventionally held in the closed flight position by latches. This facilitates opening the cowlings for engine maintenance. However, the discontinuity caused by splitting the annular structure into two C-shaped cowlings impairs aerodynamic performance in direct jet propulsion. This also negatively impacts thrust reverser performance, since no deflection grid or membrane can be installed in the flap locking zone, typically in the 6 o'clock position.
[0012] Therefore, there remains a need to improve the design of the moving structures of inverters, particularly to achieve a better compromise between performance and ease of maintenance. Description of the invention
[0013] To at least partially meet the need mentioned above, the invention first relates to a thrust reverser for an aircraft propulsion system, the reverser comprising a fixed structure and a movable structure that can be translated relative to the fixed structure along a longitudinal central axis of the reverser, between a forward position of direct thrust and a rearward position of thrust reversal, the fixed structure comprising air deflection means configured to generate a counter-thrust airflow, in the rearward position of thrust reversal of the movable structure, the movable structure comprising:
[0014] - a first entity comprising an external radial delimitation structure of a secondary vein of the propulsion assembly, the air deflection means being arranged radially around the external radial delimitation structure in the forward direct thrust position, and the external radial delimitation structure extending around the longitudinal central axis over an angular sector greater than 240°;
[0015] - a second entity comprising at least one external reversing hood equipped with an internal skin for external radial delimitation of the secondary vein, the internal skin being arranged downstream of the external radial delimitation structure of the first entity, the external reversing hood being mounted on the first entity so as to be able to be moved relative to it between a closed flight position, and an open maintenance position.
[0016] The invention breaks with existing inverter designs, since it provides a mobile structure with a hybrid O and C architecture. Indeed, the first entity of the mobile structure of the inverter according to the invention is similar to an O architecture, while the second entity, with the external inverter cover(s) mounted on the first entity, is similar to a C architecture.
[0017] Thanks to this hybrid architecture, the inverter allows for better performance in direct jet and thrust reversal.
[0018] This is primarily due to the reduction in air disturbances as it passes through the external radial boundary structure of the secondary duct, which has a very large angular range. This reduces drag and specific fuel consumption. The invention is therefore the result of technological research aimed at significantly improving aircraft performance and, in this respect, contributes to reducing the environmental impact of aircraft (decarbonization). Secondly, it is possible to deploy the air deflection devices over a larger angular range, for example, identical or similar to that of the external radial boundary structure of the secondary duct, namely at least 240°, or even 270°, or more.
[0019] Furthermore, maintenance operations are also facilitated, since access to the engine can be obtained by simply moving the external reverser cover(s) from their closed flight position to their open maintenance position.
[0020] The invention preferably provides for at least one of the following optional technical features, taken individually or in combination.
[0021] According to a preferred embodiment of the invention, the first entity also comprises an external front structure surrounding the external radial delimitation structure of the secondary vein, and delimiting with it a housing open axially upstream, housing in which is located at least a part of the air deflection means in the forward direct thrust position.
[0022] According to another preferred embodiment of the invention, the external reverser hood also includes a front external structure extending forward relative to the inner skin, the front external structure surrounding the external radial boundary structure of the first entity, and defining with it a housing open axially upstream, housing in which is located at least a part of the air deflection means in the forward direct thrust position.
[0023] Preferably, the external inverter hood is mounted on the first entity using external hood hinges.
[0024] Preferably, the fixed structure of the inverter comprises: - an internal radial delimitation structure of the secondary vein, arranged radially opposite the external radial delimitation structure of the first entity;
[0025] - at least one internal inverter hood equipped with an external skin for internal radial delimitation of the secondary vein, the external skin being arranged downstream of the internal radial delimitation structure, and also arranged radially opposite the internal skin of the external inverter hood.
[0026] Preferably, the internal reverser hood is mounted so that it can be moved between a closed flight position and an open maintenance position, preferably using internal hood hinges.
[0027] Preferably, the inverter comprises at least one longitudinal beam, and preferably two, each equipped with a fixed part and a movable part connected together by a rail system, so as to allow translational movement of the movable structure, the movable part of each longitudinal beam, integrated into the first entity of the movable structure of the inverter, extending rearward beyond the external radial boundary structure of the secondary vein.
[0028] Preferably, the external radial boundary structure of the secondary channel is formed by two half-shells, and the two half-shells, at their two circumferential ends, are respectively fixed to the two movable sections of the two longitudinal beams, the two fixed sections of these two beams being equipped with beam hinges. This design allows the first element of the inverter's movable structure to be functionalized, providing the possibility of opening the two half-shells, for example, for major maintenance operations or for quick engine change operations, such as "QEC" (Quick Engine Change).
[0029] It should be noted that opening the two halves of the shell, by pivoting them around the axes of the beam hinges, first requires the removal of a fastening device, which preferably requires the use of one or more tools by the operators. This type of removal is, of course, more time-consuming than simply unlocking the locks on a reversing gear cover, which can be done manually by the operators without tools.
[0030] Preferably, the second entity comprises two external inverter covers, mounted respectively on the two movable parts of the two longitudinal beams. These two covers are preferably also in the form of two half-shells, generally in the shape of a C.
[0031] Preferably, the fixed structure of the inverter comprises two internal radial boundary structures of the secondary stream, fixed to one another at two circumferential ends thereof, using a removable fastening device preferably comprising screws, and the two internal radial boundary structures, at the two circumferential ends thereof opposite the circumferential ends cooperating with the fastening device, are respectively fixed to the two fixed parts of the two longitudinal beams, preferably using two bifurcations respectively.
[0032] Therefore, when the two half-shells of the first section of the inverter's moving structure are pivoted to open, the two internal radial boundary structures of the inverter's fixed structure pivot in conjunction with these half-shells, along the axes of the beam hinges. This pivoting is performed for heavy and / or significant maintenance operations, or for a quick engine change, such as a "Q.EC" type change.
[0033] Thus, as mentioned above, the reversing mechanism is preferably configured so that each half-shell can be moved, along with its associated internal radial delimiter structure, around the beam hinges, from a closed flight position to an open maintenance or engine change position. The reversing mechanism preferably includes two removable mechanical reinforcement tools, each configured to mechanically connect one of the half-shells to its associated internal radial delimiter structure, at least during their movement from the closed flight position to the open maintenance or engine change position. These tools allow the stiffness of these elements to be restored, preferably on or near the circumferential ends opposite those connected to the longitudinal beams. These tools are preferably retained when these elements are in the open maintenance or engine change position.
[0034] In flight, these tools are preferably not mounted on the reversing gear. However, the reversing gear can incorporate specific interfaces for mounting these tools, which are therefore preferably intended to be mounted on the reversing gear only on the ground, before and / or during the opening of the two aforementioned halves of the shell.
[0035] Preferably, the inverter includes secondary flow closure means, configured to be deployed in the thrust reversal rearward position of the moving structure, so as to force at least a portion of the air from the secondary flow radially outwards, in the direction of the air deflection means.
[0036] The sealing means can be rigid elements such as sealing flaps, and / or flexible elements such as sealing membranes. In the case of flaps, their deployment in the stream can be achieved conventionally using connecting rods, or without connecting rods or any other connection to the fixed internal part of the inverter. In the latter case, no flap actuation means passes directly through the secondary stream, which advantageously reduces drag.
[0037] Air deflection means include rigid elements such as deflection grilles, and / or flexible elements such as deflection membranes. A combination of both is also possible, without departing from the scope of the invention.
[0038] Finally, the invention also relates to an aircraft propulsion system comprising such a reverser.
[0039] Other advantages and features of the invention will appear in the detailed, non-limiting description below.
[0040] Brief description of the drawings
[0041] The detailed description that follows refers to the attached drawings on which:
[0042] [Fig. 1] is a schematic perspective view of part of a propulsion assembly according to a preferred embodiment of the invention, comprising a thrust reverser shown in a direct thrust configuration; [Fig. 2] is a schematic perspective view of the reverser shown in the previous figure, from another angle of view, and shown in a direct thrust configuration;
[0043] [Fig. 3] is a longitudinal half-section view of the reverser shown in the previous figures, with the reverser shown in direct thrust configuration;
[0044] [Fig. 4] is a longitudinal half-section view similar to that of Figure 3, with the reverser shown in a thrust reversing configuration;
[0045] [Fig. 5] is a cross-sectional view of the inverter, taken along the VV line of Figure 3;
[0046] [Fig. 6] is a cross-sectional view of the inverter, taken along line VI-VI of figure 3;
[0047] [Fig. 7] is a cross-sectional view of the inverter, similar to that in Figure 6, with various rear elements of the inverter shown in the open maintenance position;
[0048] [Fig. 8] is a perspective view of the inverter shown in its configuration in Figure 7;
[0049] [Fig. 9] is a perspective view of the inverter similar to that of the previous figure, from a different viewing angle;
[0050] [Fig. 10] is a cross-sectional view of the inverter, similar to that in Figure 5, with various forward elements of the inverter shown in the open maintenance or engine change position;
[0051] [Fig. 11] is a schematic perspective view of part of a propulsion assembly according to another preferred embodiment of the invention, comprising a thrust reverser shown in a direct thrust configuration;
[0052] [Fig. 12] is a longitudinal half-sectional view of the reverser shown in the previous figure, with the reverser shown in direct thrust configuration; [Fig. 13] is a schematic longitudinal half-sectional view of a propulsion assembly according to another preferred embodiment of the invention, comprising a thrust reverser shown in direct thrust configuration;
[0053] [Fig. 14] is a longitudinal half-section view of the reverser shown in the previous figure, with the reverser shown in thrust reversing configuration;
[0054] [Fig. 15] is a schematic longitudinal half-section view of a propulsion assembly according to another preferred embodiment of the invention, comprising a thrust reverser shown in a direct thrust configuration;
[0055] [Fig. 16] is a longitudinal half-section view of the reverser shown in the previous figure, with the reverser shown in thrust reversing configuration;
[0056] [Fig. 17] is a schematic longitudinal half-section view of a propulsion assembly according to another preferred embodiment of the invention, comprising a thrust reverser shown in a direct thrust configuration.
[0057] Detailed description of implementation methods
[0058] Figure 1 shows a propulsion assembly 1 of an aircraft, presenting a longitudinal central axis Al.
[0059] Subsequently, the terms "upstream" and "downstream" are defined relative to a general SI sense of gas flow through the propulsion assembly 1, along the axis Al when this assembly generates direct thrust. The terms "upstream" and "downstream" could respectively be substituted by the terms "front" and "rear," with the same meaning.
[0060] The propulsion unit 1 includes a turbomachine 2, a nacelle 3 and a mounting mast 4 intended to connect the propulsion unit 1 to a wing (not shown) of the aircraft.
[0061] The turbomachine 2 in this example is a twin-spool, twin-flow turbojet engine of conventional design, preferably with a shrouded fan. Therefore, its design will not be described further. The nacelle 3 comprises a front section forming an air intake 13, a mid-section 14 with two fan cowls enclosing the fan casing, and a rear section 15 containing the thrust reverser. In Figure 1, the front and mid-sections 13 and 14 of the nacelle are shown schematically and only partially.
[0062] During operation, an airflow 20 enters the propulsion assembly 1 through the air inlet 13, passes through the blower, 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 secondary channel 21B is radially delimited inwards and outwards by various elements, which are specific to the present invention, in the rear section 15, incorporating a thrust reverser 30 centered on the axis A1.
[0063] With reference now to figures 1 to 10, the thrust reverser 30 will be described, which is presented in the form of a preferred embodiment of the invention.
[0064] Firstly, the inverter 30 comprises on the one hand a fixed structure 31 attached to the blower housing, and on the other hand a structure 29 movable relative to the fixed structure 31. More precisely, the movable structure 29 is displaceable in translation relative to the fixed structure 31, along the longitudinal central axis Al of the inverter, between an advanced position of direct thrust represented on figure 3, and a rearward position of thrust reversal represented on figure 4.
[0065] The fixed structure 31, for example, includes a front frame 46, onto which is attached a streamlined aerodynamic part called a deflection edge 46B, which guides the flow of the reverse jet. This front frame 46 allows the connection with the fan casing, in a known manner that will not be described in further detail.
[0066] The fixed structure 31 also includes air deflection means configured to generate a counter-thrust airflow. In this preferred embodiment, these means take the form of fixed and rigid deflection grids 32. These grids 32, only one of which is visible in Figures 3 and 4, are arranged in succession in the circumferential direction of the inverter.
[0067] One of the features of the invention is to provide a hybrid O and C architecture for the mobile structure 29. To do this, the mobile structure 29 comprises a first entity 29a, which has an O architecture, and a second entity 29b mounted on the first entity 29a, which has a C architecture.
[0068] The first entity 29a comprises an external radial boundary structure 72 for the secondary channel 21B. This structure 72, preferably annular in shape and centered on the axis A1, extends around it over an angular sector greater than 240°, or even greater than 270°. In the circumferential direction, the only missing portion allows the passage of the mast 4, as well as the attachment of the external radial boundary structure 72 to this mast. The air deflection grilles 32 are arranged radially around the external radial boundary structure 72 when the movable structure 29 is in its forward direct thrust position. This same structure 72 also carries internally the flaps 73 for closing off the secondary channel 21B.The deployment of these flaps 73 is ensured here in a conventional manner, with connecting rods 74 passing through the secondary vein 21B, one end of which is mounted on one of the flaps 73, and the other end of which is mounted on the fixed structure of the inverter.
[0069] Alternatively, the deployment of the shutter flaps 73 could be carried out without a connecting rod and without any other means crossing the secondary vein in a direct jet configuration, this design being known under the English name "linkless".
[0070] The flaps 73 also follow one another in the circumferential direction, over a cumulative angular extent identical or close to that of the external radial boundary structure 72, just like the set of deflection grids 32.
[0071] In this preferred embodiment, the first entity 29a also includes a forward external structure 76, surrounding the external radial boundary structure 72. These two structures 72 and 76, having the same angular sector, together define an annular housing 54 open axially upstream, in which at least part of the grids 32 are located in the forward direct thrust position. The external radial boundary structure 72 may be continuous along the aforementioned angular sector, or made up of angular sections arranged circumferentially and fixed to one another. The same applies to the forward external structure 76, whose radially external surface is exposed to the air outside the propulsion assembly 1.
[0072] In this preferred embodiment, the external radial delimitation structure 72 of the secondary vein 21B is formed by two half-shells 72a, 72b, each generally C-shaped, fixed to one another at their two circumferential ends, preferably arranged clockwise at 6 o'clock. This fixing is achieved using a removable fixing device 78, schematically shown in Figure 5, preferably comprising screws and requiring one or more tools for the operators to be assembled and disassembled.
[0073] Similarly, the external front structure 76 is formed by two half-shells 76a, 76b, each generally C-shaped, fixed to one another at their two circumferential ends, preferably arranged in a clockwise position at 6 o'clock. This fixing is achieved using the same removable fixing device 78, or alternatively using another identical or similar removable fixing device. The four half-shells 72a, 72b, 76a, 76b are thus distributed two by two to form two front hoods 80a, 80b, each in general C shape and double walled, to delimit the housing 54 of the grids 32. By way of indication, the fixing of the two front hoods 80a, 80b can be carried out using one or more devices 78 cooperating only with the circumferential ends of two external half-shells 76a, 76b, without departing from the scope of the invention.Even though this type of device 78 requires tools, particularly for tightening / loosening the screws, it should be noted that opening these two front covers 80a, 80b should be very occasional and not required for every maintenance operation. In fact, opening the front covers 80a, 80b is preferably only done for major maintenance or for quick engine changes. The reversing unit 30 also includes two longitudinal beams 82 arranged on either side of the mast 4, in the circumferential direction. Each beam 82 is equipped with a fixed part 82' and a moving part 82'', connected by a rail system 84, so as to allow translational movement of the moving structure 29.The movable part 82" of each longitudinal beam 82 is integrated into the first entity 29a of the movable structure 29 of the inverter, and it extends rearward beyond the external radial boundary structure 72, and the external front structure 76.
[0074] The four half-shells 72a, 72b, 76a, 76b, at their four circumferential ends opposite the circumferential ends cooperating with the fastening device 78, are respectively fixed to the two movable parts 82" of the two longitudinal beams 82, in clockwise positions close to 12 o'clock. The two fixed parts 82' of these two beams 82 are in turn equipped with beam hinges 86 connected to the mast 4, and defining articulation axes of the external front cowlings 80a, 80b parallel or substantially parallel to the axis Al.
[0075] The second entity 29b of the mobile structure 29 comprises two external reversing hoods 86a, 86b, arranged on either side of the mast 4. Each of these hoods is equipped with an inner skin 88 for external radial delimitation of the secondary vein 21B, as well as an outer skin 90 intended to be enveloped by air external to the propulsion assembly 1. The two skins 88, 90 meet at a point at the rear of these hoods 86a, 86b, in order to delimit the outlet of the secondary vein 21B. The two external reversing hoods 86a, 86b are mounted respectively on the two beams 82, and more precisely on the two movable parts 82" of these two beams 82, by means of external hood hinges 92. The two axes of these hinges 92 are also preferably parallel or substantially parallel to the axis Al.
[0076] Each of the two external rear reversing gear covers 86a, 86b is mounted on the movable section 82" of one of the two beams 82, so that it can be moved relative to the beam between a closed flight position and an open maintenance position for carrying out the most common maintenance operations. The external rear reversing gear covers 86a, 86b are held in the closed flight position conventionally using latches 99, preferably manually operated by the operators.
[0077] Here, the two skins 88, 90 are arranged downstream of the external radial boundary structure 72 and the external front structure 76 of the first entity 29a.
[0078] The junction 94 between the rear end of the external front covers 80a, 80b, and the front end of the external rear reverser covers 86a, 86b, is preferably made in such a way as to allow radial and axial retention of these covers relative to each other. For this purpose, any conventionally shaped arrangement can be considered, such as a J-shaped, V-shaped, etc., rib.
[0079] The fixed structure 31 of the inverter comprises at least one internal radial boundary structure 96a, 96b of the secondary flow 21B, arranged radially opposite the external radial boundary structure 72. More precisely, it consists of two internal radial boundary structures 96a, 96b of the secondary flow, fixed to one another at their two circumferential ends by means of another removable fastening device 78, preferably also comprising screws. These two structures 96a, 96b also form two generally C-shaped half-shells, located axially at the two external front covers 80a, 80b. The connecting rods 74 for deploying the secondary flow shut-off flaps 73 are articulated on these structures 96a, 96b.
[0080] The two internal radial delimitation structures 96a, 96b, at the level of the two circumferential ends of these opposite the circumferential ends which cooperate with the fixing device 78, are respectively fixed to the two fixed parts 82' of the two longitudinal beams 82. This fixing is carried out by means of radial bifurcations 98, visible in particular on figures 2 and 5.
[0081] After dismantling all the fastening devices 78, each external front cowl 80a, 80b, incorporating two half-shells 72a, 72b, 76a, 76b, can be moved with its associated internal radial boundary structure 96a, 96b, around the beam hinges 86. This allows the elements 80a, 80b, 96a, 96b to move from a closed flight position shown in particular in figures 1 to 3 and 5, to an open maintenance or engine change position, shown in particular in figure 10.
[0082] As illustrated in Figure 10, the reverser may include two removable mechanical reinforcement tools 100, each configured to mechanically connect one of the half-shells 72a, 72b and its associated internal radial boundary structure 96a, 96b, at least during their movement from the closed flight position to the open maintenance or engine change position. Preferably, these tools 100 are also retained during maintenance operations, when the openings are in the open maintenance position, again to provide the required structural reinforcement between the elements 80a, 80b, 96a, 96b. The tools 100 are thus arranged in the space corresponding to the secondary channel, and are preferably located on or near the circumferential ends intended to cooperate with the fastening devices in the closed position.
[0083] Furthermore, the fixed structure 31 of the inverter comprises, downstream and in line with the internal radial boundary structures 96a, 96b, two internal inverter covers 102a, 102b. Each of these covers 102a, 102b is equipped with an outer skin 104 for the internal radial boundary of the secondary vein 21B. This outer skin is therefore arranged downstream of the internal radial boundary structures 96a, 96b, and also arranged radially opposite the inner skin 88 of the external inverter covers 86a, 86b. It is noted that the internal reverser hoods 102a, 102b are arranged downstream of the external radial boundary structure 72, and also downstream of the junction 94, as this allows a wide opening for maintenance of these hoods 102a and 102b, without having to open the external upstream structure 72 and internal structure 96. This advantageously facilitates access to the motor.
[0084] Furthermore, each of the two internal reversing hoods 102a, 102b is mounted so as to be able to be moved between a closed flight position shown in particular in figures 1 to 3 and 6, and an open maintenance position shown in particular in figures 7 to 9. To do this, internal hood hinges 106 are provided, with axes preferably parallel or substantially parallel to the axis Al, and connecting these hoods 102a, 102b to the mast 4. Here too, the closed position of these hoods can be ensured by simple locks 99, which can be operated manually, without tools, by the operators.
[0085] The operation of the thrust reverser 30 will be described below.
[0086] First, it is noted with reference to Figure 4 that the deflection edge 46B and the upstream end of the half-shells 72a, 72b axially define, on the secondary channel 21B, a radial extraction opening 56 for at least a portion 20B' of the secondary flow 20B. This opening 56 of the secondary channel 21B is therefore delimited upstream by the deflection edge 46B. Conventionally, this edge flares radially outwards towards the rear, to define an airflow 20B' intended to pass through this opening 56 when the moving structure is in this rearward thrust reversal position. In other words, the deflection edge 46B, here made rigidly, has a shape that gradually moves away from the axis Al from front to back, to guide / deflect the air through the opening 56 and towards the grids 32, in thrust reversal configuration.On the contrary, this opening 56 of the secondary vein 21B is notably delimited downstream by the upstream end of the half-shells 72a, 72b.
[0087] In order to force at least part 20B' of the secondary flow 20B towards the opening 56, the flaps 73 are deployed in the secondary channel 21B, using the connecting rods 74, and in a conventional manner, by recoiling the mobile structure 29. Indeed, in figure 3, the closing flaps 73 are of conventional design, namely that they are pressed against the half-shells 72a, 72b in direct thrust configuration, and tilted radially into the secondary channel in thrust reversal configuration.
[0088] As mentioned previously, several fixed grids 32 are preferentially arranged in succession within the inverter along the circumferential direction. These grids 32 can all be identical and arranged in the same way, so as to generate a counter-thrust flux 20B" with an axial component towards the front.
[0089] For supporting the deflection grids 32, the inverter includes a rear grid support frame 60 and a front grid support frame 70, each extending in the circumferential direction. The front support frame 70 is integrated into the fixed structure 31 of the inverter, near the deflection edge 46B and the opening 56.
[0090] Furthermore, for conventional and routine maintenance operations, only the hoods 86a, 86b and 102a, 102b are pivoted around the hinges 92, 106, as shown in Figures 7 to 9. On the other hand, for less frequent major maintenance operations, such as heavy and / or significant operations, or for a quick engine change, the external front hoods 80a, 80b and their associated internal radial boundary structures 96a, 96b are pivoted around the hinges 86, as shown in Figure 10. It should be noted, however, that this opening, via the beam hinges 86, also causes the two external reverser hoods 86a, 86b to move, since they pivot in conjunction with the external front hoods 80a, 80b of the first entity 29a of the moving structure, on which they are mounted. With reference now to figures 11 and 12, another preferred embodiment of the invention is shown.The only difference from the previous preferred embodiment lies in the placement of the external structure forward 76. The two external half-shells 76a, 76b, generally C-shaped, are now respectively integrated into the two external reversing hoods 86a, 86b, belonging to the second entity 29b of the reversing movable structure 29. Indeed, each half-shell 76a, 76b extends forward the outer skin 90, so as to cover the deflection grids 32 in the direct jet configuration, and thus participate in the external radial delimitation of the housing 54. Each external half-shell 76a, 76b therefore also surrounds one of the internal half-shells 72a, 72b.
[0091] Figures 13 and 14 represent another preferred embodiment of the invention, in which the means for obturating the secondary vein are replaced by one or more flexible elements, such as one or more deployable obturating membranes 62. In direct jet configuration, each membrane 62 can be housed in the housing 54, radially between the grids 32 and the internal half-shells 72a, 72b. One end of each membrane 62 is, for example, fixed to the rear frame 60, while the opposite end is fixed to the deployment rods 74. Figures 15 and 16 represent another preferred embodiment of the invention, in which the deflection grids are replaced by one or more flexible elements, such as deflection membranes 64. In direct jet configuration, each membrane 64 can be housed in the housing 54, radially between the grids 32 and the outer half-shells 76a, 76b.One end of each membrane 64 is for example attached to the rear frame 60, while the opposite end is attached to the front frame 70. The grids 32 and the membranes 64 can also be arranged in combination, without going out of the scope of the invention.
[0092] Finally, Figure 17 illustrates another preferred embodiment of the invention, in which each sealing membrane 62 is folded around the grids 32 in a direct jet configuration. To achieve this, in the direct jet configuration, each membrane 62 can be housed in the housing 54, comprising a first portion located radially between the grids 32 and the inner half-shells 72a, 72b. Each membrane 62 flows around the grids 32 via the rear frame 60 and includes a second portion located radially between the grids 32 and the outer half-shells 76a, 76b. One end of each membrane 62 is, for example, attached to an upstream end of the outer half-shells 76a, 76b, while the opposite end is attached to the deployment rods 74.
[0093] Various modifications can be made to the invention described above by a person skilled in the art, by way of non-limiting examples only. All the features disclosed above, in the various preferred embodiments and their alternatives, are combinable. Furthermore, it should be noted that in all the figures described above, elements bearing 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) and a movable structure (29) that can be translated relative to the fixed structure along a longitudinal central axis (Al) of the reverser, between an advanced position of direct thrust, and a rearward position of thrust reversal, the fixed structure (31) comprising air deflection means (32, 64) configured to generate a counter-thrust airflow, in the rearward thrust reversal position of the mobile structure (29), the mobile structure (29) comprising: - a first entity (29a) comprising an external radial delimitation structure (72) of a secondary vein (21B) of the propulsion assembly, the air deflection means (32, 64) being arranged radially around the external radial delimitation structure (72) in the forward direct thrust position, and the external radial delimitation structure (72) extending around the longitudinal central axis (Al) over an angular sector greater than 240°; - a second entity (29b) comprising at least one external reversing hood (86a, 86b) equipped with an inner skin (88) for external radial delimitation of the secondary vein (21B), the inner skin (88) being arranged downstream of the external radial delimitation structure (72) of the first entity (29a), the external reversing hood (86a, 86b) being mounted on the first entity (29a) so as to be able to be moved relative to it between a closed flight position, and an open maintenance position.
2. Inverter according to claim 1, characterized in that the first entity (29a) also comprises an external front structure (76) surrounding the external radial delimitation structure (72) of the secondary vein, and delimiting with it a housing (54) open axially upstream, housing in which at least a part of the air deflection means (32, 64) are located in the forward direct thrust position.
3. Inverter according to claim 1, characterized in that the external inverter cover (86a, 86b) also comprises an external front structure (76) extending forward relative to the inner skin (88), the external front structure (76) surrounding the external radial delimiting structure (72) of the first entity (29a), and delimiting with it a housing (54) open axially upstream, housing in which at least a part of the air deflection means (32, 64) are located in the forward direct thrust position.
4. Inverter according to any one of the preceding claims, characterized in that the external inverter hood (86a, 86b) is mounted on the first entity (29a) using external hood hinges (92).
5. Inverter according to any one of the preceding claims, characterized in that the fixed structure (31) of the inverter comprises: - an internal radial delimitation structure (96a, 96b) of the secondary vein, arranged radially opposite the external radial delimitation structure (72) of the first entity (29a); - at least one internal inverter hood (102a, 102b) equipped with an external skin (104) for internal radial delimitation of the secondary vein (21B), the external skin (104) being arranged downstream of the internal radial delimitation structure (96a, 96b), and also arranged radially opposite the internal skin (88) of the external inverter hood (86a, 86b).
6. Inverter according to the preceding claim, characterized in that the internal hood of the inverter (102a, 102b) is mounted so as to be able to be moved between a closed flight position, and an open maintenance position, preferably by means of internal hood hinges (106).
7. Inverter according to any one of the preceding claims, characterized in that it comprises at least one longitudinal beam (82), and preferably two, each equipped with a fixed part (82') and a movable part (82") connected to each other by a rail system (84), so as to allow translational movement of the movable structure (29), the movable part (82") of each longitudinal beam (82), integrated into the first entity (29a) of the inverter's movable structure, extending rearward beyond the external radial boundary structure (72) of the secondary channel (21B). 8.Thrust reverser according to any one of the preceding claims, characterized in that it comprises secondary flow closure means (73, 62), configured to be deployed in the thrust reversal rearward position of the mobile structure (29), so as to force at least a portion of the air from the secondary flow radially outwards, in the direction of the air deflection means (32, 64).
9. Inverter according to the preceding claim, characterized in that the sealing means (73, 62) are rigid elements such as sealing flaps (73), and / or flexible elements such as sealing membranes (62).
10. Aircraft propulsion assembly (1) comprising a reverser (30) according to any one of the preceding claims.