Aircraft propulsion unit

Abstract

An aircraft propulsion assembly (1) is disclosed, comprising a nacelle and a turbojet engine, the nacelle comprising an outer casing (5), the outer casing comprising a fan cowl (4) and the turbojet engine comprising at least one fan casing (6, 6'), the fan cowl (4) and the at least one fan casing (6, 6') being connected by at least one supporting structure (11, 110) and being configured to define an internal space, the internal space being used to accommodate the blade cascade of a thrust reverser (8) having a sliding blade cascade, the thrust reverser (8) being configured to be moved between a first position and a second position by at least one actuator (15), the propulsion unit (1) being notable in that the at least one supporting structure (11, 110) comprises at least one hole (14, 140), the at least one hole being configured to allow a portion of the at least one actuator (15) to pass through.

Description

Technical Field

[0001] The invention relates to an aircraft propulsion unit. Background Art

[0002] The aircraft is propelled by one or more turbojets, each of which is housed in at least one nacelle. Typically, the nacelle has a tubular structure comprising an air intake section upstream of the turbojets, an intermediate section for surrounding the fan of the turbojets, and a downstream section for accommodating thrust reversal devices. The downstream section of the nacelle surrounds the gas generator of the turbojets, which terminates in a nozzle located downstream of the turbojets. In particular, the air intake section of the nacelle comprises a front lip having an overall annular shape, which intercepts the inlet airflow of the nacelle directed to the fan. In particular, for aerodynamic reasons, it is desirable that the front lip of the nacelle be extended so as to extend the laminar flow region downstream. However, its extension is not without influence on the design of the rest of the nacelle. In particular, the nacelle must have mechanical rigidity properties to reduce its deformation during operational stresses.

[0003] In patent FR3004700, a nacelle with an extended front lip for an aircraft turbojet is described. This nacelle for an aircraft turbojet comprises an inner casing of substantially cylindrical shape, an outer casing of substantially cylindrical shape, a downstream partition and an upstream partition fixed to said inner casing, and a front lip arranged in front of said upstream partition, the inner casing being of the type comprising an upstream part, the upstream part comprising an acoustic shield connected to a downstream part comprising a fan casing by an attachment flange. The front lip extends on the upstream partition and is arranged thereon to be fixed to a corresponding edge of the outer casing, thereby maintaining maintenance access to said attachment flange.

[0004] A downstream diaphragm connects the fan cowl situated on the outer casing to the fan cowl situated on the inner casing. The downstream diaphragm is arranged at the limit of the contraction area of ​​the thrust reverser.

[0005] However, a disadvantage of using such a partition is that a useful volume or capacity is required in order to integrate it between the inner and outer casings, which involves increasing the longitudinal dimensions of the nacelle; this is all the more true when the nacelle is of the type that includes sliding cascade thrust reversers, thus preventing the possibility of shortening the nacelle. Summary of the invention

[0006] The object of the present invention is to remedy this drawback by providing an aircraft propulsion unit comprising a nacelle and a turbojet engine, the nacelle comprising an external casing comprising a fan cowl, the turbojet engine comprising at least one fan casing, the fan cowl and the at least one fan casing being connected by at least one supporting structure and being configured to define an internal space for housing a grid of sliding-blade thrust reversers, the thrust reversers being configured to move between a first position corresponding to a position in which the reversers are retracted without producing thrust reversal, and a second position corresponding to a position in which the reversers are deployed by at least one actuator so as to allow the production of thrust reversal, the propulsion unit being notable in that the supporting structure comprises at least one hole configured to allow the passage of part or all of at least one actuator.

[0007] The advantage of this feature is that the support structure integrates a part of the volume of the thrust reverser. Thus, the thrust reverser is arranged further upstream of the propulsion unit and thus the propulsion unit can be shortened.

[0008] Advantageously, a portion of at least one actuator passes through a respective aperture without contacting the support structure.

[0009] The fact that a portion of the at least one actuator passes through the at least one corresponding hole without contacting the support structure prevents the support structure from taking over the load from the at least one actuator. Thus, the function of the support structure is dedicated to supporting the fan guard.

[0010] Likewise advantageously, the support structure is configured to be fixed to at least one fan casing at the height of a flange, referred to as flange for the support structure, the support structure having a profile configured to allow it to be fixed to a selected area of ​​the fan casing so as to ensure good mechanical strength over time.

[0011] This profile makes it possible to adapt the configuration of the supporting structure to fasten it to the fan cowl in the desired area, while taking into account the volume of the thrust reverser.

[0012] Also advantageously, the profile of the support structure comprises at least one inclined portion allowing an offset along the longitudinal axis of the propulsion unit between the first portion and the second radial portion of the support structure.

[0013] In particular, the at least one supporting structure has a substantially S-shape, a cone shape or a ramp shape along the longitudinal axis of the propulsion unit.

[0014] According to one possibility, the at least one supporting structure comprises at least one portion arranged longitudinally at the level of at least one fan casing.

[0015] The support structure thus makes it possible, where appropriate, to constitute an additional interface for a non-restrictive fan shroud in the engine environment.

[0016] According to another possibility, the at least one supporting structure is configured to connect the fan guard and the at least one fan housing around the periphery of the at least one fan housing, the supporting structure being continuous over 360°.

[0017] This feature allows the support structure to support the fan guard around the perimeter of at least one fan housing, thereby providing effective support.

[0018] According to another possibility, at least one supporting structure is discontinuous in the circumferential direction.

[0019] Such a discontinuous configuration of the supporting structure makes it possible to reduce its weight and therefore the weight of the propulsion unit.

[0020] In another embodiment, at least one actuator is fixed to the support structure.

[0021] Such a stabilization between the support structure and the at least one actuator can be achieved by a universal joint.

[0022] This allows the support structure to bear part of the load from the at least one actuator.Thus, the support structure participates in the recovery of the stress path experienced by the at least one actuator.

[0023] Also particularly, at least one supporting structure comprises an additional wall.

[0024] The additional wall serves to strengthen the support of the fan guard.

[0025] Also in particular, the propulsion unit comprises at least a first fan housing and a second fan housing, the second fan housing being arranged downstream of the first fan housing.

[0026] Advantageously, at least one actuator comprises at least one fitting configured to be fixed to the second fan casing at the level of at least one flange, referred to as flange for the actuator.

[0027] The securing of the fitting to the at least one actuator flange ensures that at least a portion of the load of the at least one actuator is exerted on the second fan housing.

[0028] According to another possibility, the at least one actuator is a jack.

[0029] According to yet another possibility, the supporting structure comprises two parts, a first part being fixed to the fan casing and a second part being fixed to at least one fan housing, said first and second parts being connected to each other by a lattice structure.

[0030] The grid structure makes it possible to form holes configured to receive each actuator of a thrust reverser.

[0031] In one embodiment, the support structure is fixed to the flange for the support structure by means of complementary parts.

[0032] The complementary sections allow the support structure to be offset without affecting the integrity of the engine.

[0033] In another embodiment, at least one support structure is integrally formed with at least one fan housing.

[0034] In yet another embodiment, the support structure is removably attached to the fan guard.

[0035] This removable fastening of the support structure to the fan guard ensures a transmission of forces between the fan guard and the at least one fan housing.

[0036] According to another embodiment, the at least one supporting structure comprises at least one hole.

[0037] This ensures ventilation of the cabin interior, in particular ventilation between the individual compartments formed by the at least one supporting structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be described in more detail by means of the various figures presented below, which will facilitate understanding of the present invention.

[0039] Figure 1 A partial cross-sectional view along the longitudinal axis of a propulsion unit according to an embodiment of the present invention is shown.

[0040] Figure 2 1 and 2 show a portion of a propulsion unit according to another embodiment of the present invention. Figure 1 Similar view.

[0041] Figure 3 1 and 2 show a portion of a propulsion unit according to another embodiment of the present invention. Figure 1 Similar view.

[0042] Figure 4a A partial cross-sectional view along the longitudinal axis of a support structure according to one embodiment of the present invention is shown.

[0043] Figure 4b is based on Figure 4a A partial cross-sectional view of the jack of an embodiment along the longitudinal axis.

[0044] Figure 5a is a cross-sectional view along the longitudinal axis of a support structure according to one embodiment of the present invention.

[0045] Figure 5bis based on Figure 5a A partial cross-sectional view of the jack of an embodiment along the longitudinal axis.

[0046] Figure 6 is a partial cross-sectional view along the longitudinal axis of a support structure according to another embodiment of the present invention.

[0047] Figure 7 FIG. 4 is a partial cross-sectional view along the longitudinal axis of a jack according to another embodiment of the present invention.

[0048] Figure 8 is a partial perspective view of securing a support structure to a first fan housing according to one embodiment of the present invention.

[0049] Fig. 9 is a perspective view of securing a support structure to a fan guard according to the present invention. DETAILED DESCRIPTION

[0050] Figure 1 A partial view of an aircraft propulsion unit 1 is shown, the propulsion unit comprising a nacelle with an air inlet lip 2, an air inlet 3, a fan cowl 4 arranged on an outer casing 5 of the nacelle, and a turbojet engine comprising a first fan casing 6 and a second fan casing 6 arranged downstream of the first fan casing 6 along the longitudinal axis of the propulsion unit 1, a thrust reverser 8 (here with sliding cascades), a main nozzle 9 and a gas injection cone 10. The upstream side of the propulsion unit 1 is located at the level of the air inlet lip 2, and the downstream side of the propulsion unit 1 is located at the gas injection cone 10.

[0051] The thrust reverser 8 with sliding blade cascade is in the retracted position, that is to say in the rest position. The retracted position is the position in which the thrust reverser does not interfere with the airflow from the fan. In this position, the thrust reverser 8 is below the outer casing 5 and more precisely housed between the inner casing 7 and the outer casing 5.

[0052] In contrast, when the thrust reverser 8 is in the deployed position, the flow from the fan is reversed and discharged to the outside of the outer casing 5 .

[0053] The support structure 11 is arranged in the static area of ​​the thrust reverser 8, that is to say the area that accommodates the thrust reverser 8 in the static position. Preferably, the support structure 11 is located at the upstream end of the static area. The support structure 11 is configured to connect the fan cowl 4 to the first fan casing 6.

[0054] More precisely, a first portion 30 of the support structure 11 is fixed to the fan guard 4 and a second portion 31 of the support structure 11 is fixed to the fan casing 6 .

[0055] The support structure 11 is fixed to the first fan housing 6 via a flange 12 for the support structure.

[0056] The second fan casing 6 ′ further comprises a first flange 18 for the actuator and a second flange 22 for the actuator located downstream of the first flange 18 for the actuator.

[0057] In this figure, according to this longitudinal section of the propulsion unit 1, the support structure 11 has a substantially S-shape, so that the support structure 11 integrates the volume of the thrust reverser 8 and is at the same time fixed to the first fan casing 6 and to the fan cover 4, in positions designed to ensure good mechanical strength over time.

[0058] like Figure 2 and 3 As shown, the support structure 11 can have different shapes.

[0059] In practice, the support structure 11 is configured to adapt to the physical constraints of the propulsion unit 1 , in particular to the volume of the thrust reverser 8 and to the fixing points of the support structure 11 on the fan cowl 4 and the first fan casing 6 .

[0060] exist Figure 1 , 2 In 3 , the flange 12 for the support structure, which allows the support structure 11 to be fixed to the first fan housing 6 , is not opposite to the position for fixing the support structure 11 to the fan casing 4 .

[0061] The support structure 11 therefore has at least one inclined portion 13 , which provides the possibility of fastening the support structure 11 to the fan casing 4 at a desired position, taking into account the volume of the thrust reverser 8 .

[0062] In fact, the longitudinal offset of the support structure 11 produced by at least one inclined portion 13 enables the second portion 31 of the support structure 11 to be fixed upstream or downstream to the fan casing 6 relative to the fixing of the first portion 30 of the support structure 11 to the fan guard 4 .

[0063] exist Figure 2 In the embodiment, the support structure 11 has a substantially S-shaped longitudinal section along the propulsion unit 1. Figure 1 The S in is in the opposite direction.

[0064] exist Figure 3 In the embodiment shown in FIG. 1 , the support structure 11 has a substantially conical shape.

[0065] Figure 4a A support structure 11 connecting the fan guard 4 to the first fan housing 6 is shown.

[0066] The support structure 11 is arranged on the circumference of the first fan housing 6 .

[0067] It is not excluded that the structure 11 is also arranged longitudinally at least partially along the longitudinal axis of the second fan casing 6 ′, thereby ensuring better resistance of the fan guard 4 .

[0068] The support structure 11 has a hole 14 configured to receive a corresponding actuator 15 of the thrust reverser 8 , here a jack.

[0069] These holes 14 may be formed by windows or openings made in the support structure 11 .

[0070] The support structure 11 includes reinforcements 19 configured to reinforce support for equipment such as TRAS, EBU and / or FADEC elements.

[0071] A TRAS element is a control module. A FADEC element is a full authority electronic control unit, and an EBU is an element such as a hydraulic unit or a fuel unit.

[0072] Here, the support structure 11 is discontinuous, as indicated by the cracks 16 .

[0073] Of course, all possible discontinuities are possible.

[0074] It should be noted that the hole 14 may also be formed by one or more discontinuous portions of the support structure 11 arranged opposite the actuator 15 .

[0075] Figure 4b Shown according to Figure 4a The actuator 15 of the illustrated embodiment.

[0076] The actuator 15 is a jack comprising a fitting 17 fixed to a first flange 18 for the actuator, which fitting is arranged on the second fan casing 6 ′ so as to support the load of the actuator 15 .

[0077] The support structure 11 , which connects the fan guard 4 to the first fan housing 6 via a flange 12 for the support structure, has a hole 14 .

[0078] The actuator 15 is arranged to pass through the hole 14 so that the support structure 11 does not contact the actuator 15 .

[0079] In other words, there is a spacing relative to the support structure 11 on either side of the actuator 15 , thereby forming the hole 14 .

[0080] exist Figure 5a In another embodiment of the invention shown, four actuators 15 of the thrust reverser 8 are fixed to the supporting structure 11 .

[0081] This fixing of each actuator 15 (here a jack) is achieved by means of a universal joint (not shown).

[0082] The support structure 11 comprises reinforcements 19 and additional reinforcements 20 which increase the stability between each actuator 15 and the support structure 11 .

[0083] Figure 5b Shown according to Figure 5a The actuator 15 of the illustrated embodiment.

[0084] Unlike the above-described embodiments, the actuator 15 is connected to the support structure 11 via a universal joint (not shown).

[0085] Furthermore, additional reinforcements 20 ensure the connection between each actuator 15 and the supporting structure 11 .

[0086] The fitting 17 bears part of the load from the actuator 15 , as does the second fan casing 6 ′ by its fixing to the fitting 17 on a first flange 18 for the actuator.

[0087] The region of the support structure 11 connected to the actuator 15 is reinforced by means of an additional reinforcement 20 such as a reinforcement or a greater thickness.

[0088] Figure 6 A support structure 110 is shown connecting the fan guard 4 to the first fan housing 6 via the lattice structure 26 .

[0089] and Figures 1 to 5b Unlike the supporting structure 11 of FIG. 1 , the supporting structure 110 consists of two parts, a first part 27 fixed to the fan guard 4 and a second part 28 fixed to the first fan housing 6 .

[0090] The first portion 27 and the second portion 28 of the support structure 110 are interconnected by a lattice structure 26 including a plurality of arms 29 .

[0091] The apertures 140 defined by the lattice structure 26 are configured to receive the actuators 15 of the thrust reverser 8 .

[0092] In practice, the holes 140 are formed by the arms 29 of the lattice structure 26 , and each actuator 15 is configured to fit between the arms 29 .

[0093] It should be noted that the first portion 27 and the second portion 28 of the support structure 110 may extend continuously for 360° or discontinuously in the circumferential direction of the fan guard 4 and the circumferential direction of the first fan case 6 , respectively.

[0094] Of course, the first portion 27 and the second portion 28 of the support structure 110 may be offset relative to each other along the longitudinal axis. In fact, as shown in this figure, the first portion 27 opposite the second portion 28 of the support structure 110 does not limit the present invention.

[0095] according to Figure 7 In another embodiment shown, the actuator 15 is fixed to the support structure 11. The fitting 17 is fixed to the second fan housing 6' on the second flange 22 for the actuator according to this other embodiment, longitudinally between the flange 12 for the support structure and the flange 22 according to Figure 4b The embodiment of the present invention is used downstream of the first flange 18 of the actuator, thereby bearing the axial load of the actuator 15.

[0096] Furthermore, the supporting structure 11 comprises a reinforcement formed by an additional wall 23 .

[0097] Figure 8 The fixing of the support structure 11 on the first fan housing 6 is shown. This fixing is carried out on the flange 12 for the support structure and on the flange 18 for the actuator via complementary parts 24. The support structure 11 is therefore not in direct contact with the flange 12 for the support structure, but is indirectly fixed via this complementary part 24.

[0098] In practice, the supporting structure is fixed to the first fan casing 6 by means of complementary portions 24 fixed to the flange 12 for the supporting structure and to the flange 18 for the actuator.

[0099] The complementary portion 24 allows the support structure 11 to be deflected without affecting the integrity of the engine.

[0100] Of course, the supporting structure 11 can be fixed directly to the flange 12 for the supporting structure, without the complementary portion 24 being required.

[0101] Furthermore, the support structure 11 may be formed integrally with the first fan housing 6 , that is, the support structure 11 and the first fan housing 6 are formed as one body.

[0102] In a manner not shown, according to Figure 6 The support structure 110 of the embodiment of FIG. 1 is fixed to the first fan housing 6 in the same manner.

[0103] Fig. 9 The fixing of the support structure 11 to the fan guard 4 is shown.

[0104] The support structure 11 is connected to the fan guard 4 by removable fixing means 25, here two nut assemblies. These removable fixing means 25 can be different, such as rivets.

[0105] This connection is made directly on the fan guard 4 .

[0106] These removable fixing means 25 ensure that the forces are transmitted to the fan guard 4 according to all degrees of freedom of the supporting structure 11 , thereby providing a force transmission between the fan guard 4 and the first fan housing 6 .

[0107] In a manner not shown, according to Figure 6 The support structure 110 of the embodiment of FIG. 1 is fixed to the fan guard 4 in the same manner.

[0108] Now, various advantages of these support structures 11 and 110 are presented below.

[0109] The support structures 11 and 110 therefore participate in the radial and longitudinal force paths between the fan guard 4 and the first fan casing 6 .

[0110] These support structures 11 and 110 make it possible to adapt the volume of the thrust reverser 8 with sliding cascades, taking into account the actuator 15 configured to displace the thrust reverser 8 from the retracted position to the deployed position, and at the same time to adapt the fixing of these support structures 11 and 110 on the first fan cowl 6 by means of the flange 12 for the support structure. In practice, this flange 12 is not always opposite the fixing point of the fan cowl 4.

[0111] Furthermore, these supporting structures 11 and 110 are airtight and may comprise one or more holes to ensure ventilation of the various compartments separated by these supporting structures 11 and 110 .

[0112] When the actuator 15 of the thrust reverser 8 is fixed to the support structures 11 and 110 , these support structures 11 and 110 can also bear part of the load of this actuator 15 .

[0113] Finally, these support structures 11 and 110 may support TRAS, FADEC or even EBU elements.

Claims

1. An aircraft propulsion unit (1) comprising a nacelle and a turbojet engine, the nacelle comprising an outer casing (5), the outer casing comprising a fan cowl (4), the turbojet engine comprising at least one fan casing (6, 6'), the fan cowl (4) and the at least one fan casing (6, 6') being connected by at least one supporting structure (11, 110) and being configured to define an inner space, the inner space being used to accommodate the cascade of a sliding cascade thrust reverser (8), the thrust reverser (8) being configured to be moved between a first position and a second position by at least one actuator (15), wherein The at least one support structure (11, 110) comprises at least one hole (14, 140) configured to allow a portion of the at least one actuator (15) to pass through, The propulsion unit comprises at least a first fan housing (6) and a second fan housing (6'), wherein the second fan housing (6') is arranged downstream of the first fan housing (6). wherein the at least one support structure (11, 110) connects the fan guard (4) to the first fan housing (6), wherein the at least one actuator (15) comprises at least one fitting (17) configured to be fixed to the second fan casing (6') at the level of at least one flange (18, 22), The support structure (11, 110) is configured to be fixed to the at least one fan casing (6, 6') at a height referred to as a flange (12) for the support structure, the at least one support structure (11, 110) being fixed to the flange (12) for the support structure by means of a complementary portion (24), the complementary portion (24) being fixed to the flange (12) for the support structure and to the flange (18) for the actuator.

2. The propulsion unit (1) according to claim 1, wherein: A portion of the at least one actuator (15) passes through the corresponding hole (14, 140) without contacting the support structure (11, 110).

3. The propulsion unit (1) according to claim 1, wherein: The support structure (11, 110) has a profile comprising at least one inclined portion (13) allowing an offset along the longitudinal axis of the propulsion unit (1) between a first portion (30) and a second radial portion (31) of the support structure.

4. The propulsion unit (1) according to claim 1, wherein: The at least one supporting structure (11, 110) has a substantially S-shape, a conical shape or a ramp shape according to the longitudinal axis of the propulsion unit (1).

5. The propulsion unit (1) according to claim 1, wherein: The at least one supporting structure (11, 110) comprises at least one portion arranged longitudinally at the height of the at least one fan casing (6, 6').

6. The propulsion unit (1) according to claim 1, wherein: The at least one support structure (11, 110) is configured to connect the fan guard (4) and the at least one fan housing (6, 6') around the periphery of the at least one fan housing (6, 6'), the support structure (11) being continuous over 360°.

7. The propulsion unit (1) according to claim 1, wherein: The at least one support structure (11, 110) is discontinuous in the circumferential direction.

8. The propulsion unit (1) according to claim 1, wherein: The at least one actuator (15) is fixed to the support structure (11, 110).

9. The propulsion unit (1) according to claim 1, wherein: The at least one actuator (15) is a jack.

10. The propulsion unit (1) according to claim 1, wherein: The support structure (110) comprises two parts, a first part (27) fixed to the fan casing (4) and a second part (28) fixed to the at least one fan housing (6, 6'), the first and second parts (27, 28) being connected to each other by a lattice structure (26).

11. The propulsion unit (1) according to claim 1, wherein: The at least one support structure (11, 110) is formed integrally with at least one fan housing (6, 6').

12. The propulsion unit (1) according to claim 1, wherein: The at least one support structure (11, 110) is removably secured to the fan guard (4).

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