Propulsion system of aircraft and aircraft

Abstract

The invention relates to a propulsion system of an aircraft and the aircraft. The propulsion system comprises: an engine comprising two parts, an engine housing and an engine core; the invention relates to an aircraft engine assembly comprising a structural duct, a pylon box configured to assemble an engine to an aircraft structure, where the structural duct comprises a fixed structure comprising at least an upper beam and a rear ring, the upper beam being fixed to an engine housing and the ring being fixed to the upper beam and the pylon box at a 12 o'clock position, and the structural duct comprising a panel, the panel is mounted on the upper beam so as to form a closed barrel that at least partially surrounds the engine core, and is configured to transfer a load from the engine housing to the pylon box.

Description

TECHNICAL FIELD

[0001] The present invention relates to the general field of attachment of engines under the wings of an aircraft. It particularly relates to a propulsion system comprising an engine, in particular a twin-flow engine, a pylon and a structural attachment allowing the transmission of loads through the pylon to the aircraft structure. The invention also applies to an aircraft equipped with such a propulsion system. BACKGROUND

[0002] REFERENCE Figure 1 The aircraft 50 comprises a plurality of propulsion systems 100 having an engine each at least partially surrounded by a nacelle 102, the propulsion systems 100 being positioned under the wings 52 of the aircraft 50. These attachment elements generally comprise a front engine attachment and a rear engine attachment, here both attached to a pylon 104.

[0003] As shown in Figure 2 The propulsion system 100 comprises an engine, a nacelle 102 positioned at least partially around the engine and a pylon 104 providing a connection between the engine and the rest of the aircraft 50, in particular the wings 52. The pylon 104 comprises a main structure 106 in the form of a box connected to the engine by a front engine attachment 166, a rear engine attachment 157 and a pair of struts 156 reacting to forces.

[0004] Although this structure is satisfactory, it is desirable to find an alternative arrangement which, among other things, allows better transmission of loads to the rear of the pylon.

[0005] The aim of the present invention is to propose an alternative to such a propulsion system. SUMMARY

[0006] The aim of the present invention is to provide an arrangement which allows better transmission of loads.

[0007] To this end, a propulsion system is proposed, comprising: an engine comprising two parts including an engine casing and an engine core; a pylon box configured to assemble the engine to an aircraft structure, wherein the structural duct comprises a fixed structure comprising at least an upper beam fixed to the engine casing and a rear ring fixed to the upper beam at a 12 o'clock position and to the pylon box, and a panel mounted on the upper beam so as to form a closed barrel at least partially surrounding the engine core and configured to transmit loads from the engine casing to the pylon box.

[0008] The propulsion system can comprise additional features considered separately or in combination:

[0009] - the upper beams are provided with hinges on which the panels are hinged so as to rotate about a longitudinal line L oriented along the axis X.

[0010] - the lower sides of the panels are attached to each other.

[0011] - the fixed structure comprises a lower beam attached to the engine casing and to the ring at the 6 o'clock position.

[0012] - the panels are attached to the lower beam by means of latches.

[0013] - the upper beams have the shape of a box.

[0014] - the upper beams comprise three spars connected with an upper skin and a lower skin to form the box.

[0015] - a centering bar is provided to hold the engine core, the centering bar being positioned so as to form a triangle, each end of the centering bar being attached to the ring and the engine core being attached to each of the centering bars.

[0016] - each spar is attached to a stringer of the engine casing.

[0017] Another object of the application is to provide an aircraft comprising a propulsion system as described above. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a side view of an aircraft provided with a propulsion system;

[0019] Figure 2 is a partial perspective view of a propulsion system according to the prior art;

[0020] Figure 3 is a schematic view of two integral parts of an engine;

[0021] Figure 4 is a perspective view of a propulsion system according to the application with the mobile structure closed;

[0022] Figure 5 is a perspective view with the mobile structure removed;

[0023] Figure 6 is a side view of a propulsion system according to the embodiment with the mobile structure closed;

[0024] Figure 7 is a cross-sectional view according to the plane H3 of Figure 6 ;

[0025] Figure 8 is a cross-sectional view according to the plane H1 / H2 of Figure 6 ;

[0026] Figure 9 is a schematic view of the load transfer in the propulsion system according to the embodiment with the movable structure opened;

[0027] Figure 10 is a perspective view of the propulsion system according to the embodiment with the movable structure opened without lower beams inside the fixed structure;

[0028] Figure 11 is a cross-sectional view of the plane A-A according to the embodiment; Figure 6

[0029] Figure 12 is a partial perspective view showing the stringers of the engine case in a transparent manner. DETAILED DESCRIPTION

[0030] For the remainder of the description, the longitudinal direction X is parallel to the axis of the engine. The transversal plane is a plane perpendicular to the longitudinal direction X. The transversal and horizontal direction Y is a direction perpendicular to the longitudinal direction X and horizontal. The transversal and vertical direction Z is a direction perpendicular to the longitudinal direction X and vertical. The vertical median plane is a plane parallel to the direction X and containing the engine axis. The terms "front" and "rear" refer to the direction of flow F (indicated by the arrow F in Figure 1 ) of the flow of air in the engine, which flows from front to rear.

[0031] Turning to Figure 3 and Figure 4 , the aircraft 50 comprises a plurality of engines 4 positioned under the wings 52 of the aircraft 50 (same view as in Figure 1 but with the propulsion system described hereafter with reference to Figures 3 to 11 .

[0032] The propulsion system comprises the engines 4 and the pylon boxes 8 providing the connection between the engines 4 and the wings 52 of the aircraft 50. As illustrated in Figure 3 , the engine generally comprises two parts, called the engine core 10 and the engine case 12 located in front of the engine core. The engine case 12 is the part surrounding or holding the fan of the engine according to the type of engine (turbojet (e.g. double-flow / bypass turbojet, turbofan engine, for example), unducted fan engine (e.g. open rotor, propfan engine, etc.). The engine core 10 is the rest of the engine not on the level of the propulsion fan. The structural duct 16 described hereafter at least partially surrounds the engine core 10.

[0033] ​The pylon box 8 comprises a main structure comprising two parts: a front part 20 which is connected to the engine mainly through a set of attachments, which will not be described in detail as they are not part of the invention, and a rear part 22 which is connected to the aircraft, and in particular to the wing, mainly through a wing attachment system. The pylon box 8 is in the form of a box comprising an upper spar 24, a lower spar 26 and two lateral panels 28, 30 to form the pylon box 8.

[0034] The duct 16 of the invention is a structural duct which allows the transmission of loads from the engine to the aircraft structure, here to the wing, through the pylon. The duct 16 comprises a fixed structure 62 and a mobile structure 64.

[0035] The fixed structure 62 of the duct 16 comprises an upper beam 66 and optionally a lower beam 68 (see Figure 5 ). The upper beam 66 of the duct 16 is attached at its front side to the engine casing 12 and at its rear side to the rear part 22 of the pylon. The front end 70 of the upper beam 66 is connected to the engine casing 12 and its rear end 72 is connected to an annular frame 74 called ring 74 which is connected to the pylon 8.

[0036] In the illustrated embodiment, the ring 74 comprises two detachable upper and lower half-rings 74A, 74B: the upper and lower half-rings 74A, 74B are attached to each other by detachable fixing means (not shown as of known type) allowing the transmission of loads to form said one-piece ring 74. This design allows both the lower half-ring and the lower beam (when present) to be separated from the rest of the propulsion system.

[0037] In the present embodiment, and as better seen in Figure 8 , the upper beam 66 comprises three longitudinal spars 76, 78, 80: one central spar 78 located at the 12 o'clock position in the symmetrical vertical median plane YZ and two lateral spars 76, 80 on either side of the central spar 78. Each spar in the present embodiment has a parallelepipedal section with four faces: for example, the spar 76 has an upper face 76A, a lower face 76B and two lateral faces 76C and 76D (see Figure 5 and Figure 8 ) (same for each spar). Also in the present embodiment, as shown in Figure 5 , the front end of each spar 76, 78, 80 is attached to a respective stringer 82, 84 of the engine casing 12 (both of them are shown in transparent manner in Figure 12 ).

[0038] This provides a firm attachment allowing the transmission of loads from the engine casing 12 to the pylon 8 through the duct 16, as illustrated by the small arrows in Figure 9 .

[0039] To increase the inertia of the upper beam 66, the spars 76, 78, 80 are connected to form a box 88 (see Figure 5 and Figure 8 ). As can be seen in Figure 8 , the upper faces 76A, 80A of the lateral spars 76, 80 are connected to the upper face 78A of the central spar 78 by respective upper skins 90, 92. The lower faces 76B, 80B of the lateral spars are connected to the lower face 78B of the central spar 78 by respective lower skins 94, 96.

[0040] The skins 90, 92, 94, 96 are curved to follow the profile of the engine core 10 and the overall profile of the duct 16. The box is fully closed at one of its longitudinal ends with the engine casing 12 and at the other longitudinal end with the ring 74. However, some other embodiments are possible: in the illustrated embodiment, the skins 90, 92, 94, 96 do not extend in the panel: compared to the overall profile of the duct, the skins 90, 92, 94, 96 follow a flat shape in order to leave enough space between the upper beam and the pylon.

[0041] Optionally, the fixed structure 62 of the duct 16 comprises a lower beam 68. As shown in Figure 5 and Figure 8 , said lower beam 68 is positioned at the 6 o'clock position in the vertical median plane YZ. Said lower beam 68 comprises an elongated longitudinal surface 201 having a double curvature to follow the profile of the duct 16, intended to follow the outer shape of the engine core: the front end 200 of the lower beam 68 is attached to the engine casing 12 and more precisely to the stringers of the engine casing. The rear end 202 of the lower beam 68 is attached to the lowest portion of the ring 74 or even can be part of the lowest portion of the ring: those solid front and rear attachments allow the transmission of loads from the engine casing to the pylon through the lower beam and the ring. The lower beam 68 comprises side edges 208, 210 in the radial direction, allowing to support latches 211 to lock lateral rotation panels 212, 213 (see Figure 8 ) on the lower beam 68, which will be described later. As shown, the lower beam is optional because the lateral panels 212, 213 can be locked to each other (see Figure 10 ). The locking by one or more latches associated with a pin and a bumper will not be described as known. Any other type of latch suitable for such a configuration can be used.

[0042] Optionally, as Figure 4 , Figure 5 , Figure 7 and Figure 10As shown, three centering rods 214, 216, and 218 can be provided to alleviate the inertial load on the cantilevered engine core 10. These rods 214, 216, and 218 are positioned in the transverse plane YZ to form a triangle around the engine core 10. Each rod is attached to the engine core approximately at its middle portion: these rods allow for limiting the displacement of the engine. Each end 220, 222 of the lower rod 218, oriented in the transverse direction Y, is attached to the lower portion of the ring 74. One end 224, 226 of the two other lateral rods 214, 216 (of the other two sides of the triangle) is attached to the lower portion of the ring near the lower rod 218, and the other ends 228, 230 are attached to the upper portion of the ring near each other.

[0043] The upper beam 66 is equipped with a hinged member 234. Figure 5 The movable structure of pipe 16 includes panels 212 and 213 hinged to hinge member 234. Figure 7 , Figure 8 , Figure 10 Panels 212 and 213 include four sides: such as Figure 10 As shown, there are upper portions 212A and 213A, lower portions 212B and 213B, front portions 212C and 213C, and rear portions 212D and 213D. Upper portions 212A and 213A are connected to the upper beam 66, allowing the panel to rotate about a line L oriented in the longitudinal direction X. Attachment to the hinge allows loads to be transferred from the upper beam to the panel. Figure 4 and Figure 10 As shown, the panel can be Figure 4 The closed position shown is the same as Figure 10 The diagram shows the operator's easy access to the open deployment positions of the engine core 10. The panel has ribs 236 in the lateral direction Y and ribs 238 in the longitudinal direction X. The lateral ribs 236 are hinged to hinge members 234, allowing the panel to rotate about a line L in the direction X. As already mentioned, two alternatives are possible regarding the lower sides 212B and 213B of the panels. In one case, the lower sides are locked to the lower beam by a classic latch. In another case, the lower sides of the two panels are locked to each other.

[0044] The front sides of the panel 212C and 213C pass through Figure 11 The classic J-ring / V-groove locking connection shown in the diagram is attached to the engine housing.

[0045] Regarding the rear 212D and 231D, as from... Figure 7 and Figure 10 As can be seen, one of the transverse ribs 236A faces the ring 74, such that when in the closed position, rib 236A pushes / presses the ring 74 (as if by...). Figure 7The panel can be connected to the fixed structure and to the engine casing using any other known mechanical connection (as indicated by the arrows in FIG. 1 1 ) in order to transmit the loads from the panel to the ring. Any other known mechanical connection can be used to connect the panel to the fixed structure and to the engine casing. For example, for the connection between the panel and the ring, a J-ring / V-groove as in Figure 11 FIG. 1 1 can be applied, or even a latch as for the connection between the panel and the lower beam.

[0046] Once the panel is in the closed position, the duct 16 will be a complete 360° cylinder that surrounds the engine core and transmits the loads to the aircraft structure.

[0047] The fixed structure and the movable structure can be provided with acoustic panels and made of fireproof material.

[0048] The structural duct 16 of the present application combines several functions: aerodynamic surface, acoustic treatment, fireproof barrier, load transmission from the engine to the pylon, easy and quick access to the engine core for maintenance. No ground support equipment is needed and the risk of damaging the duct, the engine or the aircraft is reduced.

[0049] As illustrated in FIG. 1 1, a classical pylon attachment system 240 is provided to connect the ring to the pylon. Figure 4

[0050] Although at least one exemplary embodiment of the present application is disclosed herein, it is to be understood that modifications, substitutions, and alternatives can be apparent to those skilled in the art and can be made without departing from the scope of the present disclosure. The disclosure is intended to cover any adaptations or variations of the exemplary embodiments. Additionally, in the present disclosure, the terms "comprising" or "comprises" do not exclude other elements or steps, the terms "a" or "an" do not exclude a plurality, and the term "or" means either one or both. Furthermore, to the extent that the term "comprising" is used in the disclosure and the claims, it is to be understood that, even if a number of features are claimed, the inventive concept can be practiced with less than all of the features. The disclosure is to be interpreted in the broadest way consistent with the principles of the invention. The disclosure is to be interpreted in the broadest way consistent with the principles of the invention. The complete disclosure of any patent or application to which this disclosure claims right of priority is hereby incorporated by reference.​

Claims

1. A propulsion system (100) of an aircraft, comprising: An engine (4) comprising two parts (10, 12) comprising an engine case (12) and an engine core (10), a pylon box (8) configured to assemble the engine (4) to an aircraft structure, wherein the structural duct comprises a fixed structure (62) comprising at least an upper beam (66) fixed to the engine case (12) and a rear ring (74) fixed to the upper beam (66) at 12 o'clock and to the pylon box (8), and the structural duct comprises panels mounted on the upper beam so as to form a closed cylinder at least partially surrounding the engine core (10) and configured to transmit loads from the engine case (12) to the pylon box (8).

2. The propulsion system (100) of claim 1, wherein, The upper beam (66) is provided with hinges (234) on which the panels are hinged so as to rotate about a longitudinal line L oriented parallel to the longitudinal axis X of the aircraft.

3. The propulsion system (100) of claim 2, wherein, Lower sides of the panels are attached to each other.

4. The propulsion system (100) according to claim 1 or 2, wherein, The fixed structure comprises a lower beam (68) attached to the engine case and to the ring at 6 o'clock.

5. The propulsion system (100) of claim 4, wherein, The panels are attached to the lower beam (68) by latches.

6. The propulsion system (100) according to any one of claims 1 to 5, wherein, The upper beam (66) has the shape of a box.

7. The propulsion system (100) of claim 6, wherein, The upper beam (66) comprises three spars (76, 78, 80) connected with upper and lower skins to form the box.

8. The propulsion system (100) according to any one of claims 1 to 7, wherein, Centering bars (214, 216, 218) are provided to hold the engine core (10), the centering bars (214, 216, 218) being positioned so as to form a triangle, each end of the centering bars being attached to the rear ring (74) and the engine core (10) being attached to each of the centering bars.

9. The propulsion system (100) of claim 7, wherein, Each spar (76, 78, 80) is attached to a stringer (82, 84) of the engine case (10).

10. An aircraft (50) comprising a propulsion system (100) according to any one of claims 1 to 9.

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