Aircraft propulsion system comprising an actuator connected to a structural arm such as an outfeed guide vane

Abstract

The invention relates to a propulsion assembly comprising an actuator (40) connected to an external housing (11) of a turbomachine by a connecting structure (45). The connecting structure (45) is fixed to a structural arm (12) connecting the external housing (11) to a hub of the turbomachine, preferably by common fastening means (60, 61), so that the arm (12) can withstand the loading forces of the actuator (40) while relieving the external housing (11). Figure for the abstract: Fig. 6

Description

Title of the invention: Aircraft propulsion assembly comprising an actuator connected to a structural arm such as an exit guide vane technical field

[0001] The invention relates to the field of aircraft propulsion systems incorporating a thrust reverser.

[0002] The invention is of particular interest for sliding-grid inverters. Prior art

[0003] High bypass ratio turbomachinery currently in use in the aeronautical sector generally includes a fan casing extended axially at the rear by an intermediate casing.

[0004] The expression "external casing" is used here to designate the assembly formed by the blower casing and the intermediate casing, or only the blower casing when the turbomachine does not include an intermediate casing.

[0005] In a conventional propulsion assembly equipped with a sliding grid reverser, as described for example in document FR2999239A1, the grids extend around the outer casing when the reverser is in direct thrust configuration.

[0006] In order to avoid excessive loading of the shell formed by the outer casing, the reversing actuators are generally connected to structural flanges formed by axial ends of the blower casing and / or the intermediate casing.

[0007] A known fixing solution in the prior art consists of mounting such an actuator on a connecting structure forming a beam fixed on one side to a front flange and on the other side to a rear flange of the blower housing.

[0008] Such a linkage structure may prove incompatible with contemporary propulsion system architectures in which the available space around the external casing is reduced.

[0009] Furthermore, there is a need to relieve the external casing, in particular with regard to the mechanical loads coming from the inverter. Description of the invention

[0010] The invention aims to provide a propulsion assembly equipped with an axially mobile structure reverser that is compatible with contemporary architectures and that allows the external casing to be reduced or optimized, in particular when the reverser's mobile structure is stressed axially towards the rear.

[0011] To this end, the invention relates to a propulsion system for an aircraft, comprising a fixed structure, a movable thrust reversing structure, and a linear actuator connected to the movable structure so as to be able to move it relative to the fixed structure in translation along a longitudinal axis. The fixed structure comprises an outer casing extending around the longitudinal axis, a hub, at least one structural arm connecting the outer casing to the hub, a linkage structure connecting the actuator to the outer casing, and means for attaching the linkage structure to the outer casing. According to the invention, the attachment means are positioned axially between a leading edge and a trailing edge of a head of the arm.

[0012] The invention makes it possible to support at least part of the actuator's forces by at least one arm, by passing them directly through it via the link structure and the fastening means.

[0013] This helps to relieve the external casing, particularly when the moving structure is stressed axially towards the rear, i.e. in thrust reversal configuration and during the movement of the moving structure towards this configuration.

[0014] The invention also makes it possible to reduce the bulk of the parts of the propulsion assembly, in particular the linkage structure, around the external casing.

[0015] The invention thus makes it possible to improve the performance of the propulsion system and is compatible with contemporary architectures with a high bypass ratio.

[0016] In one embodiment, the arm forms an outlet guide vane, also called an "OGV" from the English "Outlet Guide Vane".

[0017] It is preferred that the mobile structure include deflection grids.

[0018] However, the invention also covers embodiments in which the propulsion assembly includes fixed deflection grids.

[0019] In an embodiment in which the grids belong to the moving structure, the actuator is connected to a rear frame of the grids.

[0020] The mobile structure preferably comprises one or more hoods.

[0021] The actuator can be connected to this or these movable covers.

[0022] When the grilles are movable, the hood(s) are preferably attached to the rear frame of the grilles.

[0023] Regarding the actuator, it is preferably a cylinder.

[0024] In one embodiment, the cylinder is telescopic.

[0025] The actuator can be configured to extend radially below the grids or, alternatively, within their thickness.

[0026] In a first embodiment, the outer casing comprises a blower casing and an intermediate casing.

[0027] According to this first variant, the arm is preferably fixed to the intermediate housing.

[0028] Alternatively, the arm can be fixed to the blower housing.

[0029] In a second embodiment, the outer casing includes a blower casing and is devoid of an intermediate casing.

[0030] In one embodiment, the fastening means extend radially through a ferrule of the external housing.

[0031] Advantageously, the fastening means can be configured to fix the arm to the external casing.

[0032] This makes it possible in particular to pool the means of fixing and to improve the transmission of forces between the arm and the connecting structure.

[0033] By way of example, the means of fastening may include screws and / or studs and / or other types of fasteners.

[0034] In one embodiment, the connecting structure includes a support element integral with the external housing.

[0035] The support element can be an interface part fixed to the outer casing by the engine manufacturer and configured so as to allow the attachment of another part of the connecting structure, such as a fitting. It is thus possible to mount or replace other parts of the connecting structure and the nacelle without altering the turbomachine, and in particular the attachment of said support element to the turbomachine, after the latter has been assembled and tested.

[0036] The connecting structure preferably comprises a fitting fixed to the support element.

[0037] In one embodiment, the propulsion assembly includes a cardan joint configured to articulate the actuator on the fitting or on another part formed by the linkage structure.

[0038] In one embodiment, the fitting is fixed to a flange of the external casing.

[0039] Thus, in one embodiment, the fitting can be fixed on one side to a flange of the external casing and on the other side to a support element as described above.

[0040] More generally, the linkage structure can be fixed on several parts of the external housing and / or the arm, in order for example to distribute the forces of the actuator and to improve the corresponding force path(s).

[0041] The connecting structure can have many geometries.

[0042] For example, the fitting of this connecting structure can form a hinge bracket extending to the right of the arm.

[0043] For another example, the fitting of the connecting structure can form a beam extending longitudinally.

[0044] In one embodiment, the linkage structure includes a front part connected to the actuator and a rear part connected to the external housing so that the actuator extends in cantilever.

[0045] Other advantages and features of the invention will become apparent from the following detailed, non-limiting description. Brief description of the drawings

[0046] The following detailed description refers to the attached drawings on which:

[0047] [Fig-1] is a schematic half-view in longitudinal section of an assembly propulsion system according to the invention, comprising a thrust reverser in direct thrust configuration;

[0048] [Fig.2] is a schematic half view in longitudinal section of the propulsion assembly of the [Fig.1], the reverser being in thrust reversal configuration;

[0049] [Fig.3] is a partial schematic view of an inverter actuation device according to the invention, comprising a cylinder and a linkage structure according to a first embodiment, the cylinder being in the retracted position;

[0050] [Fig.4] is a partial schematic view of the actuation device of [Fig.3], with the cylinder in the deployed position;

[0051] [Fig.5] is a partial schematic perspective view of the actuation device of the [Fig.3];

[0052] [Fig.6] is a partial schematic view of an inverter actuation device according to the invention, comprising a cylinder and a linkage structure according to a second embodiment, the cylinder being in the retracted position;

[0053] [Fig.6A] is a partial schematic cross-sectional view of the actuation device of the [Fig.6];

[0054] [Fig.7] is a partial schematic view of an inverter actuation device according to the invention, comprising a cylinder and a linkage structure according to a third embodiment, the cylinder being in the retracted position;

[0055] [Fig.7A] is a partial schematic cross-sectional view of the actuation device of the [Fig.7]. Detailed description of implementation methods

[0056] Figures 1 and 2 represent a propulsion assembly 1 of an aircraft having a longitudinal central axis Al.

[0057] Subsequently, the terms "forward" and "rear" are defined relative to a principal SI direction of gas flow through the propulsion assembly 1 along the axis Al when it generates thrust.

[0058] 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 of the aircraft.

[0059] In this example, the turbomachine 2 is a turbofan engine comprising, from front to rear, a fan 5, a low-pressure compressor 6, a high-pressure compressor 7, a combustion chamber 8, and a high-pressure turbine pressure 9 and a low pressure turbine 10. Compressors 6 and 7, combustion chamber 8 and turbines 9 and 10 form a gas generator.

[0060] The turbojet 2 has an external casing 11 surrounding the fan 5 and connected to a hub of the turbojet 2 by structural arms 12 which extend radially through the secondary duct 21B.

[0061] In a manner known per se, the arms 12 are circumferentially distributed around the axis Al and are each fixed by a foot to said hub and by a head to the external casing 11, in particular so as to transmit forces between the gas generator and the mast of the propulsion assembly 1.

[0062] In this example, the arms 12 form outlet guide vanes allowing the secondary flow 20B to be straightened behind the blower 5.

[0063] Each of the arms 12 comprises for this purpose a front end 12A forming a leading edge and a rear end 12B forming a trailing edge.

[0064] The nacelle 3 comprises a front section forming an air inlet 13, a middle section which includes blower hoods 14 enveloping the external casing 11 and a rear section 15.

[0065] 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.

[0066] The secondary vein 21B is delimited radially towards the inside by a fixed internal fairing 18 which encloses the gas generator and radially towards the outside by the external casing 11 and, in the configuration of [Fig.1], by reversing hoods 33 forming the rear section 15 of the nacelle 3 (see further below).

[0067] The nacelle 3 includes a thrust reverser 30 forming a movable structure relative to the turbojet 2 and in particular relative to the external casing 11 which forms a fixed structure of the propulsion assembly 1.

[0068] In this example, the moving structure of the inverter 30 includes deflection grids 32, the aforementioned hoods 33, shutter flaps 34 and connecting rods 35.

[0069] Fig. 1 shows the inverter 30 in a direct thrust configuration.

[0070] In this configuration, the hoods 33 are in a closed position, or advanced position, in which they are substantially supported on a rear end of the middle section and in which the grilles 32 are housed in a space radially delimited by the outer casing 11 on one side and by the blower hoods 14 on the other.

[0071] In direct thrust configuration, the flaps 34 are retracted within a cavity 36 (see [Fig.2]) formed by the hoods 33.

[0072] The inverter 30 thus makes it possible to channel the secondary flow 20B towards the rear of the propulsion assembly 1 in order to generate thrust.

[0073] Fig. 2 shows the reverser 30 in a thrust reversal configuration.

[0074] In this configuration, the hoods 33 are in an open position, or retracted position, in which they are longitudinally away from the median section so as to define a radial opening of the secondary vein 21B. The grids 32 extend through this radial opening.

[0075] In thrust reversal configuration, the flaps 34 are deployed radially in the secondary duct 21B so as to direct the secondary flow 20B towards the grids 32 which allow the flow thus redirected to be directed towards the front of the propulsion assembly 1 in order to generate a counter-thrust.

[0076] The invention relates more specifically to the actuation of the moving structure of the inverter 30.

[0077] Figures 3 to 5 show an actuation device according to a first embodiment.

[0078] This actuation device includes a cylinder 40 comprising a body 41 and a rod 42 movable relative to the body 41 between a retracted position, illustrated in [Fig.3], and a deployed position, illustrated in [Fig.4].

[0079] Cylinder 40 is here a hydraulic cylinder.

[0080] In this example, the cylinder 40 is telescopic, making it possible to overcome the phenomena of deflection and expansion of the moving structure compared to a non-telescopic cylinder. In one embodiment, the cylinder 40 can be non-telescopic.

[0081] The actuation device may also include a buckling limitation device (not shown).

[0082] With reference to Figures 3 and 4, the rod 42 is moved between the retracted and extended positions along an actuation direction parallel to the AL axis. In an alternative embodiment not shown, the actuation direction may be oblique with respect to the AL axis.

[0083] The rod 42 of the cylinder 40 includes a free end 43 connected to the moving structure of the inverter 30.

[0084] In this example, the free end 43 of the rod 42 is articulated on a rear frame 32B of the grids 32 which is integral with the hoods 33 or one of the hoods 33, it being understood that the inverter 30 can have a conventional architecture in C, D or O.

[0085] In this example, the body 41 of the cylinder 40 is articulated to a link structure 45 via a cardan joint 46 around an articulation axis A2 passing through a plane orthogonal to the axis Al (see [Fig.5]).

[0086] In this example, the cardan 46 is mounted on a part of the body 41 located near a front end of the cylinder 40, opposite the free end 43 of the rod 42, so as to envelop the body 41 of the cylinder 40.

[0087] Radially, the cylinder 40 extends between an internal surface and an external surface of the grids 32, that is to say in their thickness.

[0088] In an unrepresented variant, the cylinder 40 extends radially inwards relative to such an internal surface of the grids 32.

[0089] The cardan 46 extends to the front of the grids 32, more precisely to a position located axially forward with respect to a front frame 32A of the grids 32, including when the cylinder 40 is in the retracted position ([Fig.3]).

[0090] The cardan 46 and the linkage structure 45 are thus configured to extend outside the volume of the grids 32, which makes it possible to increase their useful deflection surface.

[0091] The connecting structure 45 of figures 3 to 5 includes a fitting 47 as well as two support elements 48 and 49 of this fitting 47.

[0092] The support elements 48 and 49 are fixed to the external casing 11.

[0093] In this embodiment, the external housing 11 comprises a blower housing 50 and an intermediate housing 51 forming an axial extension of the blower housing 50.

[0094] In a manner known per se, the blower housing 50 forms a ferrule 52 comprising at its axial ends a front flange 53 and a rear flange 54. Similarly, the intermediate housing 51 forms a ferrule 55 comprising at its axial ends a front flange 56 and a rear flange 57.

[0095] The rear flange 54 of the blower housing 50 and the front flange 56 of the intermediate housing 51 are connected to each other by fastening means (not shown) such as bolts or rivets.

[0096] With reference to [Fig.3], the head of each of the arms 12, that is to say their end radially outwards with respect to the axis Al, is arranged radially opposite an internal surface of the ferrule 55 formed by the intermediate housing 51 and is fixed to this ferrule 55 by fixing means 60 and 61 such as studs or screws.

[0097] Each of the arms 12, as well as their leading edge 12A and trailing edge 12B, extend axially between the front flanges 56 and rear flanges 57 of the intermediate housing 51.

[0098] In this example, the fastening means 60 form a first row and are positioned axially near the leading edge 12A of the arms 12. The fastening means 61 form a second row and are positioned axially near the trailing edge 12B of the arms 12, axially towards the rear with respect to the fastening means 60.

[0099] Each of the fastening means 60 and 61 extends radially through the ferrule 55 of the intermediate housing 51.

[0100] In this non-limiting example, each of the arms 12 is thus fixed to the intermediate housing 51 at the front by two fixing means 60 and at the rear by two fixing means 61.

[0101] The support element 49 of the linking structure 45 is disposed on an external surface of the ferrule 55 of the intermediate housing 51.

[0102] In this example, the support element 49 is circumferentially aligned with one of the arms 12 and extends axially between the leading edge 12A and the trailing edge 12B of the head of this arm 12. In the following description, reference is made by default to this arm 12.

[0103] The support element 49 is fixed to the ferrule 55 by the same fixing means 60 which secure the arm 12 to the intermediate housing 51.

[0104] Regarding the support element 48, in this example it has an L-shaped section forming a radial leg and an axial leg.

[0105] The radial leg of the support element 48 is disposed against a front surface of the rear flange 54 of the blower housing 50 and is fixed to it and to the front flange 56 of the intermediate housing 51 by means of fixing such as screws or bolts (not shown) passing axially through these different parts.

[0106] In this example, the support elements 48 and 49 form interface pieces designed to remain attached to the external housing 11 in the event of maintenance work on the actuation device. The support elements 48 and 49 are configured for this purpose to allow the fitting 47 to be attached to them removably, possibly with the destruction of the corresponding fastening means (not shown).

[0107] With reference to [Fig.5], the fitting 47 extends longitudinally so as to form a double beam comprising two arms 47A and 47B extending circumferentially on either side of the cylinder 40 (see [Fig.5]).

[0108] A front part of the arms 47A and 47B is articulated on the cardan joint 46.

[0109] Each of the arms 47A and 47B of the fitting 47 forms a surface arranged opposite said axial lug of the support element 48. The arms 47A and 47B are secured to this axial lug of the support element 48 by means of fastening such as screws or bolts (not shown).

[0110] The fitting 47 includes a rear part forming a rear leg 70 extending circumferentially so as to connect the arms 47A and 47B to each other (see [Fig.5]).

[0111] The rear tab 70 of the fitting 47 is disposed on an external surface of the support element 49 and is fixed to this support element 49 by fastening means such than screws or studs (not shown) which in this example are different from the aforementioned means of fixing 60.

[0112] Of course, the fitting 47 may have a different geometry from that illustrated in [Fig.5] and form, for example, a beam having a single arm (not shown) extending radially under the cylinder 40.

[0113] In this example, the means for fixing the fitting 47 to the support element 49 are axially arranged near the leading edge 12A of the head of the arm 12 (see [Fig.3]).

[0114] The link structure 45 thus makes it possible to connect the cylinder 40 to the external housing 11 so as to define a main path of force passing through the arm 12. In particular, when the mobile structure of the reverser 30 is in thrust reversal configuration or is moved towards this configuration, the mobile structure exerts on the cylinder 40 an axial force which is supported by the arm 12, this force passing through the fitting 47, the support element 49 and the fastening means 60.

[0115] The invention thus makes it possible to reduce the load on the outer casing 11 and a fortiori on the ferrule 52 of the blower casing 50 which is liable to deform in the event of the breakage of one or more blades of the blower 5. In this regard, the body 41 of the cylinder 40 and the fitting 47 are mounted in cantilever on the blower casing 50 taking into account the relative arrangement of the support elements 48 and 49 (see [Fig.3]).

[0116] The fitting 47 acts in effect as an axial load transfer beam supported by the arm 12.

[0117] Figures 6 and 6A show an actuation device according to a second embodiment.

[0118] This second embodiment is described solely in terms of its differences from the first embodiment. The preceding description applies by analogy, with regard to these differences.

[0119] In this example, the connecting structure 45 comprises a fitting 47 and a single support element 49.

[0120] The support element 49 is fixed to the ferrule 55 by the same fixing means 60 and 61 which secure the arm 12 to the intermediate housing 51.

[0121] The fitting 47 of the connecting structure 45 has a U-shaped section (see [Fig.6A]) comprising a base 80 and two radial tabs 81 and 82.

[0122] The base 80 of the fitting 47 is disposed on the support element 49 and fixed to it by means of fixing (not shown) such as screws.

[0123] With reference to [Fig. 6A], which shows the actuation device along a cutting plane passing through the axis A2 of articulation of the body 41 of the cylinder 40 to the fitting 47, the lugs 81 and 82 extend circumferentially on either side of the cardan joint 46 and are connected to the cardan joint 46 so that the axis A2 is radially offset with respect to the axis actuation of the cylinder 40 so that the fitting 47 extends outside the volume of the grids 32.

[0124] The fitting 47 and more generally the connecting structure 45 thus extend to the arm 12 so that the main path of effort is substantially shortened compared to the first embodiment.

[0125] In this example, the cardan 46 is mounted on a middle part of the body 41 of the cylinder 40 which is close to the center of gravity of the cylinder 40.

[0126] This arrangement improves the transfer of forces from cylinder 40 by arm 12.

[0127] This arrangement also makes it possible to reduce the risk of buckling of the cylinder 40 and therefore to reduce its size and the mass of the actuation device.

[0128] In this example, a retention structure 90 is fixed on the rear flange 54 of the blower housing 50 so as to form an axial stop for the cylinder 40 allowing it to be retained for example in the event of a blower blade(s) breaking 5.

[0129] Figures 7 and 7A show an actuation device according to a third embodiment.

[0130] This third embodiment is described solely in terms of its differences from the second embodiment. The preceding description applies by analogy, with regard to these differences.

[0131] In this embodiment, the body 41 of the cylinder 40 is articulated on the fitting 47 by a frame-type structure 100.

[0132] With reference to [Fig.7A], which shows the actuation device of [Fig.7] along a cutting plane passing through the axis A2 of articulation of the body 41 of the cylinder 40 to the fitting 47, the carriage 100 comprises a base 101 and fitting elements 102 and 103 extending on either side of the body 41 of the cylinder 40.

[0133] The base 101 and the fitting elements 102 and 103 extend radially below the grids 32, outside the volume they define, which allows their useful deflection surface to be increased.

[0134] Such a mount 100 is also more compact than a gimbal 46 such as those illustrated in figures 3 and 6A.

[0135] The invention is not limited to the embodiments described above. Thus, for example, the outer casing 11 may be without an intermediate casing 51, the arms 12 may be connected to the blower casing 50 and the connecting structure 45 may be connected to the blower casing 50 so as to transmit the loads of the actuation device to one of these arms 12.

[0136] For another example, in each of the embodiments described above, the actuator 40 can be connected to the linking structure 45 by a joint element different from the cardan 46 of Figures 3 to 6A and the mount 100 of [Fig.7A].

[0137] The embodiments described above can also be combined. For example, in a variant not shown, the cardan joint 46 of the actuation device of [Fig.3] can be replaced by a bearing 100 similar to that of [Fig.7A], the geometry of the fitting 47 being able to be adapted accordingly.

[0138] Of course, the actuation device can include several actuators 40 and corresponding linkage structures 45 as described above, each actuator 40 being able to be configured to define a main force path passing through a respective arm 12 of the propulsion assembly 1.

[0139] Furthermore, the inverter 30 may differ from that given as an example in these embodiments. In particular, the inverter may include fixed grids, in which case the actuation device is configured to actuate only one or more movable covers of the inverter.

Claims

Demands

1. Aircraft propulsion assembly (1) comprising a fixed structure (11), a movable thrust reversing structure (32, 33), and a linear actuator (40) connected to the movable structure (32, 33) so as to be able to move it relative to the fixed structure (11) in translation along a longitudinal axis (A1). The fixed structure (11) comprises an outer casing (11) extending around the longitudinal axis (A1), a hub, at least one structural arm (12) connecting the outer casing (11) to the hub, a linkage structure (45) connecting the actuator (40) to the outer casing (11), and means (60, 61) for attaching the linkage structure (45) to the outer casing (11). The movable structure (32, 33) comprises deflection grids (32), and the attachment means (60, 61) are positioned axially between an edge leading edge (12A) and trailing edge (12B) of a head of the arm (12),characterized in that the connecting structure (45) comprises a support element (49) integral with the external casing (11) and a fitting (47) fixed to the support element (49).

2. Propulsive assembly (1) according to claim 1, wherein the fastening means (60, 61) extend radially through a ferrule (55) of the outer casing (11).

3. Propulsion assembly (1) according to claim 1 or 2, wherein the fastening means (60, 61) are configured to fix the arm (12) to the external casing (11).

4. Propulsion assembly (1) according to claim 1, wherein the fitting (47) is fixed on a flange (54) of the outer casing (11).

5. Propulsion assembly (1) according to any one of claims 1 to 4, wherein the linkage structure (45) comprises a front part connected to the actuator (40) and a rear part (70) connected to the external housing (11) so that the actuator (40) extends in cantilever.

6. Propulsive assembly (1) according to any one of claims 1 to 5, wherein the arm (12) forms an exit guide vane.

7. Propulsion assembly (1) according to any one of claims 1 to 6, wherein the outer casing (11) comprises a blower casing (50) and an intermediate casing (51), the arm (12) being fixed to the intermediate casing (51).

8. Propulsion assembly (1) according to any one of claims 1 to 7, wherein the actuator (40) is a telescopic cylinder.