Aircraft wing-pylon connector

Abstract

A first aspect of the present invention provides an aircraft assembly including a wing and an engine pylon. A rear end portion of the engine pylon is connected to the wing via a bushing and at least one fastener. The aircraft assembly is configured such that, during operation of the aircraft assembly on the aircraft, the bushing transmits only lateral loads between the engine pylon and the wing, and the at least one fastener transmits only vertical loads between the engine pylon and the wing.

Description

Technical Field

[0001] The present invention relates to an aircraft assembly comprising a wing and an engine mounting pylon connected to the wing, and to an aircraft comprising such a connected wing and pylon. Background Art

[0002] Most conventional aircraft have engines mounted to the wings via engine pylons. For commercial airliners, there is a trend toward using higher-bypass ratio engines, which have larger diameters than lower-bypass ratio engines. To accommodate large-diameter engines while maintaining adequate clearance between the engine and the ground, it is desirable to minimize the vertical distance between the top of the engine and the lower surface of the wing.

[0003] Conventionally, the engine pylon is attached to the wing box by a set of couplings interposed vertically between the wing box and the main structure of the pylon. These couplings generally constitute a statically defined joint, or a low-level, highly static joint. These couplings transmit forces, including the thrust loads generated by the engine, between the engine pylon and the wing box, while allowing a certain degree of freedom of movement between the two components (due to the loads and stiffness of the pylon and wing box). Known designs of such couplings require the top surface of the engine pylon to be vertically spaced from the lower surface of the wing box and are therefore unsuitable for use with engines of very large diameters. Summary of the Invention

[0004] A first aspect of the present invention provides an aircraft assembly comprising a wing and an engine pylon. A rear end portion of the engine pylon is connected to the wing via a bushing and at least one fastener. The aircraft assembly is configured such that, during operation of the aircraft assembly on the aircraft, the bushing transmits only lateral loads between the engine pylon and the wing, and the at least one fastener transmits only vertical loads between the engine pylon and the wing.

[0005] Optionally, the aircraft assembly is configured such that the sleeve only transfers transverse loads perpendicular to the direction of travel of the aircraft.

[0006] Optionally, the aircraft assembly is configured such that the sleeve transfers transverse loads parallel and perpendicular to the direction of travel of the aircraft.

[0007] Optionally, the sleeve extends upwardly from an upper surface of the engine mounting pylon.

[0008] Optionally, the lower surface of the wing includes an opening configured to receive the free end of the sleeve.

[0009] Optionally, the opening comprises a slot having a major axis extending parallel to the direction of travel of the aircraft.

[0010] Optionally, the opening is configured to match the cross-sectional profile of the sleeve such that relative lateral movement of the sleeve and the opening is substantially prevented.

[0011] Optionally, the lower surface of the wing includes a fitting, and wherein the sleeve and the at least one fastener engage the fitting.

[0012] Optionally, the wing comprises a lower cover, and the fitting is attached to the lower cover.

[0013] Optionally, the fitting is located between the top surface of the engine mounting pylon and the lower cover.

[0014] Optionally, the vertical height of the fitting is less than 100 mm.

[0015] Optionally, the bushing is a fail-safe bushing.

[0016] Optionally, the at least one fastener is a fail-safe fastener.

[0017] A second aspect of the invention provides an aircraft comprising the assembly of the first aspect.

[0018] Optionally, the aircraft further includes an ultra-high bypass ratio (UHBR) engine mounted on the engine mounting pylon. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0020] Figure 1a is a schematic side view of an exemplary aircraft assembly according to the present invention;

[0021] Figure 1b yes Figure 1a A schematic top view of an engine mounting pylon of an exemplary aircraft assembly;

[0022] Figure 2a is a schematic diagram of an exemplary sleeve of an aircraft component according to the present invention engaged with a first exemplary opening of an aircraft component according to the present invention;

[0023] Figure 2b is a schematic diagram of an exemplary sleeve of an aircraft component according to the present invention engaged with a second exemplary opening of an aircraft component according to the present invention;

[0024] Figure 2c It passes through Figure 2a Exemplary sleeves and openings or Figure 2b cross-sections of exemplary sleeves and openings;

[0025] Figure 3ais a perspective view of another example aircraft assembly according to the present invention, wherein most of the wing structure is omitted;

[0026] Figure 3b yes Figure 3a A top view of an engine mounting pylon of an exemplary aircraft assembly;

[0027] Figure 3c yes Figure 3a a perspective view of an exemplary aircraft assembly;

[0028] Figure 3d It passes through Figure 3a a cross-section of an exemplary aircraft assembly; and

[0029] Figure 4 is a perspective view of an exemplary aircraft including an aircraft assembly according to the present invention. DETAILED DESCRIPTION

[0030] The following examples all relate to an aircraft assembly comprising a wing and an engine pylon, wherein the rear end of the engine pylon is connected to the wing via a bushing and at least one fastener. The aircraft assembly is configured such that, during operation of the assembly on the aircraft, the bushing transmits only lateral loads between the engine pylon and the wing, and the (or each) fastener transmits only vertical loads between the engine pylon and the wing. In other words, the bushing does not transmit any vertical loads, and the (or each) fastener does not transmit any lateral loads.

[0031] Example aircraft assemblies according to the present invention offer the advantage of relatively low torsional loads applied to the wing structure during aircraft operation. This is because the vertical height of the one or more bushings and fasteners is relatively small compared to alternative known arrangements in which a fitting having a relatively large vertical height connects the rear or side surface of the rear end portion of the engine mounting pylon to the wing. Reduced torsional loads applied to the wing structure mean that less wing structure reinforcement is required at the location where it engages the pylon connection mechanism. This, in turn, reduces the weight of the wing and makes its manufacture simpler.

[0032] Figure 1a FIG2 is a schematic side view of an exemplary aircraft assembly 1 according to the present invention. Assembly 1 includes a wing 11 and an engine mounting pylon 12. Pylon 12 is connected to wing 11 via a forward connector 13 and a rearward connector 14. The details of forward connector 13 are not relevant to the present invention, and therefore, this feature will not be described in detail. Rearward connector 14 includes a sleeve 15 and at least one fastener 16. Figure 1b FIG is a top view of the pylon 12 showing the arrangement of the sleeve 15 and at least one fastener 16. Figure 1bIt can be seen that the particular exemplary assembly 1 includes two fasteners 16, which are arranged on either side of the sleeve 15. The aircraft assembly 1 may be included in any type of aircraft, but it may be particularly advantageous when used on a commercial airliner.

[0033] Bushing 15 extends substantially vertically relative to the cruising orientation of aircraft assembly 1. One end of bushing 15 is fixedly attached to the lower surface of wing 11 or the upper surface of pylon 12. The other (free) end of bushing 15 engages an opening (not shown) in the other of the lower surface of wing 11 and the upper surface of pylon 12. The engagement of bushing 15 with the opening allows some axial movement of the bushing relative to the opening. However, relative radial movement of bushing 15 and the opening is limited by the engagement between bushing 15 and the opening, as described further below. In some examples, bushing 15 is a fail-safe bushing. For example, the bushing may include an inner pin nested within an outer pin, each of the inner and outer pins being capable of independently carrying and transmitting a predetermined load. The predetermined load is at least as great as the load that bushing 15 is expected to withstand during operation of an aircraft incorporating assembly 1.

[0034] Figure 2a and Figure 2b An example sleeve 25 is shown fixedly mounted on the upper surface of the engine mounting pylon 22 (only on the Figure 2a 27a and 27b, each formed in the lower surface of the wing 21.

[0035] The first exemplary opening 27a comprises a slot having a width substantially equal to the diameter of the sleeve 25 but a length significantly greater than the diameter of the sleeve 25. The long axis of the slot is parallel to the direction of travel D of the aircraft including the wing 21 and the pylon 22. T The width of the opening 27a may be slightly larger than the diameter of the sleeve 25 to allow relative vertical (axial) movement of the sleeve 25 and the opening 27a. The first exemplary opening 27a is configured to substantially prevent the sleeve 25 and the opening 27a from moving perpendicular to the direction of travel D. T However, the sleeve 25 and the opening 27a are in the direction of travel D. T Some relative lateral (radial) movement is allowed. T The amount of relative movement depends on the length of the opening 27a. The length of the opening 27a is large enough to accommodate the manufacturing tolerances associated with the wing 21 and the pylon 22. This helps to connect the pylon 22 to the wing 21. Figure 2aThe aircraft assembly of the sleeve-opening combination is configured such that the sleeve transfers only transverse loads perpendicular to the direction of travel of the aircraft. In such an example, thrust loads are not transferred through the sleeve 25. Such an assembly may include a forward connector (or some other feature) configured to transfer transverse loads between the pylon 22 and the wing 21 in a direction parallel to the direction of travel (i.e., thrust loads).

[0036] Figure 2b The second exemplary opening 27b shown in FIG is shaped to match the circumferential shape of the sleeve 25. The second exemplary opening 27b is thereby configured to substantially prevent all relative lateral (radial) movement of the sleeve 25 and the opening 27b. In the example shown, the sleeve 25 has a circular cross-section, and the opening 27b includes a cylindrical recess having a diameter substantially equal to the diameter of the sleeve 25. The diameter of the opening 27b may be slightly larger than the diameter of the sleeve 25 to allow relative vertical movement of the sleeve 25 and the opening 27b. Figure 2b The aircraft assembly of the sleeve-opening combination is configured such that the sleeve transfers lateral loads both parallel and perpendicular to the direction of aircraft travel. In such an example, thrust loads are transferred by sleeve 25. Such an assembly may include a front connector configured to transfer lateral loads between pylon 22 and wing 21 only in a direction perpendicular to the direction of travel.

[0037] Figure 2c Shown along line AA through Figure 2a and Figure 2b For both openings 27a and 27b, the cross section looks identical. Figure 2c The wings 21 and pylons 22 are shown in a "symbolic" configuration corresponding to the situation of the aircraft on the ground. Figure 2c It can be seen in FIG. 1 that the opening 27 (which in this example has the form of a recess) is configured to allow the sleeve 25 to be moved relative to the opening 27 in the vertical direction D. z The amount of relative vertical movement allowed depends on the depth of the recess and the proximity of the distal end of the sleeve 25 to the base of the recess in the indicative configuration. In some examples, the recess and / or sleeve are configured such that all relative vertical (axial) movement of the sleeve 25 and opening 27 expected to occur during operation of the aircraft can be accommodated.

[0038] Figures 2a to 2c Two of the sleeve-opening combinations shown in FIG are suitable for inclusion in Figure 1a and Figure 1b The sleeve 25 and the openings 27a, 27b may have the same configuration as described above. Figure 1a and Figure 1bThe configuration of the front connector 13 may be different depending on the specific configuration of the rear connector 14. For example, if the rear connector 14 includes Figure 2a If the rear connector 14 comprises a sleeve-opening combination, then the front connector 13 can be configured to transfer thrust loads between the pylon 12 and the wing 11 (or the aircraft assembly can include some other mechanism for transferring thrust loads). In contrast, if the rear connector 14 comprises Figure 2b If the sleeve-opening combination is such that thrust loads are transferred between the pylon 12 and the wing 11 via the rear connector 14, the forward connector 13 does not need to be configured to transfer thrust loads. However, as previously mentioned, these details of the forward connector 13 are outside the scope of the present invention.

[0039] Back to Figure 1a and Figure 1b , the (or each) fastener 16 comprises a tensioning bolt of any suitable design. In the example shown, the assembly 1 includes two fasteners 16, which are arranged symmetrically about the direction of travel of the aircraft including the assembly 1. In other examples, the assembly 1 may include one, three or four fasteners 16 in any suitable arrangement. A greater number of fasteners 16 may be used, but this may not be desirable due to the resulting weight, cost and installation time penalties. In some examples, at least one of the fasteners 16 may be a fail-safe fastener. In some examples, the fail-safe function is provided by the assembly 1, which needs to include at least twice the number of fasteners 16 to handle the operational loads expected to be experienced by the fasteners 16. In some examples, at least one of the fasteners 16 may be a single-sided fastener.

[0040] The or each fastener 16 passes through a fastener hole in the structure of the wing 11 and through a fastener hole in the structure of the pylon 12. The diameter of each of the fastener holes is significantly larger than the diameter of the shank of the fastener 16 passing through the fastener hole, thereby allowing a certain amount of relative lateral (radial) movement of the fastener 16 and the fastener hole. This ensures that the (or each) fastener 16 only transmits vertical loads between the engine mounting pylon 12 and the wing 11. The diameter of the fastener hole can be selected to accommodate all relative lateral movement of the fastener 16 that is expected to occur during operation of the aircraft. In some examples, the head end of the (or each) fastener 16 can abut the wing 11, and in other examples, the head end of the (or each) fastener 16 can abut the pylon 12, which is most suitable for the preferred manufacturing process of the assembly 1.

[0041] Figures 3a to 3dA specific example aircraft assembly 3 is shown, which includes a wing 31 suitable for a commercial passenger aircraft and an engine mounting pylon 32. The wing 31 and the pylon 32 may have any of the features of the exemplary wings 11, 21 and pylons 12, 22 described above. The wing 31 includes a reinforcing bracket 311 disposed within the interior space of the wing 31 and a fitting 312 disposed on the lower surface of a lower cover 313 of the wing 31. Figure 3a The main structure of wing 31 is omitted in the figure, so that bracket 311 and fitting 312 are visible. Fitting 312 and reinforcement bracket 311 are included in the rear connector of aircraft assembly 3. Fitting 312 is fixedly attached to reinforcement bracket 311 by fasteners 316 that pass through the lower cover 313 of wing 31. Fitting 312 and reinforcement bracket 311 are configured to react to loads transferred from pylon 32 to the wing and prevent excessive loads from being transferred to the lower cover 313 of wing 31. Figure 3a The engine mounting pylon 32 is shown with its rear end connected to a reinforcement bracket 311 and a fitting 312. Region 33 of the pylon 32 is configured to be connected to the wing 31 via a forward connector, but all features associated with the forward connector have been removed. Figure 3a It is omitted here because the front connecting piece is not related to the present invention.

[0042] The engine mounting pylon 32 is connected to a reinforcement bracket 311 and a fitting 312 of the wing 31 by means of a sleeve 35 and four fasteners 36 . Figure 3b 3 is a top view of the rear end portion of pylon 32, illustrating the arrangement of bushings 35 and fasteners 36. Bushings 35 and fasteners 36 may have any of the features described above for exemplary bushings 15, 25 and exemplary fasteners 16, 26. During operation of aircraft assembly 3 on an aircraft, bushings 35 transfer only lateral loads between engine mounting pylon 32 and wing 31, and each of fasteners 36 transfers only vertical loads between pylon 32 and wing 31.

[0043] Figure 3c and Figure 3d The structure of the rear connection between the wing 31 and the pylon 32 is shown in detail. Figure 3c This is a perspective view of the assembly 3 viewed from the rear of the rack 32. Figure 3c The interior of the rack 32 is omitted so that the interior space of the rack 32 is visible. Figure 3d It is along Figure 3b Line BB passes through the cross section of component 3.

[0044] The bushing 35 is integrally formed with the fitting 312 and extends downwardly from the lower surface of the fitting 312 (the fitting 312 being considered to form part of the lower surface of the wing 31). The bushing 35 is a fail-safe bushing comprising an inner pin 35a nested within an outer pin 35b. Each of the inner pin 35a and the outer pin 35b is configured to independently withstand and transmit all loads expected to be experienced by the bushing 35 during operation of an aircraft incorporating the assembly 3. The distal (free) end of the bushing 35 is received in a circular opening in the top of the pylon 32. This opening is lined with a bushing 39 (in the Figure 3d 35 and the hanger 32 are formed. The sleeve 35 is formed to have a substantially uniform diameter and a substantially uniform width. The sleeve 35 is preferably shaped to fit the hanger 32 and the bushing 39. The sleeve 35 is preferably shaped to fit the hanger 32 and the bushing 39. The bushing 39 is preferably shaped to fit the hanger 32 and the bushing 39. The bushing 39 is preferably shaped to fit the hanger 32 and the bushing 39. The bushing 39 is preferably shaped to fit the hanger 32 and the bushing 35 ...

[0045] Each fastener 36 comprises a tensioning bolt. Each fastener 36 extends through a stack of structures comprising the top wall of pylon 32, fitting 312, lower cover plate 313 of wing 31, and the flange of reinforcement bracket 311. The hole in the structure through which the stem of each fastener 36 extends has a diameter larger than the diameter of the fastener stem to prevent any lateral load transfer between the fastener 36 and the structure through which it passes. The head end of fastener 36 is disposed within the interior of pylon 32. In this particular example, fastener 36 is a single-faced fastener, so that the tail end of fastener 36 does not need to be accessed during installation. This means that the interior of wing 31 does not need to be entered during the process of forming assembly 3. In other examples, it may be advantageous to locate the head end of one or more of the fasteners 36 within the interior of wing 31, for example to avoid the need to enter the interior of pylon 32 during the process of forming assembly 3.

[0046] The reinforcement bracket 311 includes two sections 311a and 311b, each of which has a substantially identical configuration. Each section 311a, 311b has a horizontal flange and a vertical flange. The horizontal flange has a lower surface configured to conform to the inner surface of the lower cover 313 of the wing 31, and the vertical flange has a lower surface configured to conform to the rib 314 (at the bottom of the wing 31). Figure 3dThe inner surface of the reinforcement bracket 311 is consistent with the side surface (visible in FIG). Segments 311a and 311b are arranged on opposite sides of rib 314. The vertical flanges are fastened to each other through rib 314 by a plurality of fasteners 315. Each horizontal flange is fastened to fitting 312 through lower wing cover 313 by at least one fastener 316. The function of reinforcement bracket 311 is to receive tensile loads from pylon 32 via fasteners 36 and lateral loads from pylon 32 via fasteners 316, and to transfer these loads to rib 314. The size, shape, and material composition of reinforcement bracket 311 are selected according to the requirements of the specific application.

[0047] The fitting 312 is shaped so that it has an upper surface that is consistent with the lower surface of the lower wing cover 313. The shape and size of the upper surface of the fitting 312 correspond to the shape and size of the combined lower surface of the horizontal flanges of the reinforcement bracket 311. The fitting 312 further includes a lower surface that is consistent with the upper surface of the pylon 32 (and is therefore in close contact with it) across one or more areas containing the location of the fastener 36. The size of the contact area is selected to help transfer the tension load from the pylon 32 to the reinforcement bracket 311. The function of the fitting 312 is to receive lateral loads from the pylon 32 (via the sleeve 35) and transfer the lateral loads (via the fastener 316) to the reinforcement bracket 311. The size, shape and material composition of the fitting 312 are selected according to the requirements of the specific application. However, preferably, the vertical height of the fitting is less than 300 mm. In some examples, the vertical height of the fitting is less than 100 mm.

[0048] In the example shown, the structure of pylon 32 is constructed to be sufficiently strong to transfer the operational loads generated by the thrust and mass of the engine mounted on pylon 32 to wing 31 via a reinforcement structure formed integrally with pylon 32. In other examples, one or more reinforcement brackets similar to reinforcement bracket 311 may be provided on and / or in the pylon to locally increase its strength at the location where the loads are transferred.

[0049] from Figures 3a to 3d As can be seen in FIG3 , the overall vertical height h of the rear connector between wing 31 and pylon 32 is very small compared to the vertical height of pylon 32. The overall vertical height of the rear connector included in assembly 3 is also very small compared to the vertical height of other known mechanisms for connecting the rear end of the pylon to a wing. This means that the torsional loads transmitted to the wing lower cover 313 and reinforcement bracket 311 due to the swinging or twisting movement of pylon 32 (which is expected during normal operation of an aircraft including assembly 3) are significantly smaller than with connectors having a greater vertical height. This allows reinforcement bracket 311 to be significantly smaller and lighter than would be the case with other known rear connector designs.

[0050] Figure 4An exemplary aircraft 40 is shown, which includes one or more aircraft assemblies according to the present invention. In particular, aircraft 40 includes a wing 401, to which an engine mounting pylon 402 is attached. Wing 401 and pylon 402 together form an aircraft assembly according to the present invention, such as any of the example assemblies 1 and 3 described above, and therefore the rear end of engine mounting pylon 402 is connected to wing 401 in the manner described above. An ultra-high bypass ratio (UHBR) engine 403 is mounted on engine mounting pylon 402. Engine mounting pylon 402 is tightly coupled to wing 401. Aircraft 40 also includes another wing, an engine mounting pylon, and a UHBR engine. Another wing and engine mounting pylon may also be included in the aircraft assembly according to the present invention.

[0051] Although the invention has been described above with reference to one or more preferred examples or embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope of the invention as defined in the appended claims.

[0052] Although the present invention has been described above primarily in the context of fixed-wing aircraft applications, it may also be advantageously applied to a variety of other applications, including but not limited to applications on vehicles such as helicopters, drones, trains, automobiles, and spacecraft.

[0053] Where the term "or" is used in the preceding description, the term should be understood to mean "and / or" unless expressly stated otherwise.

Claims

1. An aircraft assembly comprising: Wings; as well as Engine mounting bracket; wherein the rear end of the engine mounting pylon is connected to the wing by a bushing and at least one fastener, and wherein the aircraft assembly is configured such that during operation of the aircraft assembly on an aircraft, the bushing transfers only lateral loads between the engine mounting pylon and the wing, and the at least one fastener transfers only vertical loads between the engine mounting pylon and the wing, One end of the sleeve is fixedly attached to one of the lower surface of the wing and the upper surface of the engine mounting pylon, and the other end of the sleeve engages an opening provided in the other of the lower surface of the wing and the upper surface of the engine mounting pylon to allow the sleeve to move in a vertical direction relative to the opening. 2 . The aircraft assembly of claim 1 , configured so that the sleeve transfers only transverse loads perpendicular to the direction of travel of the aircraft. 3 . The aircraft assembly of claim 1 , configured such that the sleeve transfers lateral loads parallel and perpendicular to the direction of travel of the aircraft.

4. The aircraft assembly according to claim 2, wherein: The opening is provided on a lower surface of the wing and comprises a slot having a major axis extending parallel to the direction of travel of the aircraft.

5. The aircraft assembly according to claim 3, wherein: The opening is disposed in the lower surface of the wing and is configured to match the cross-sectional profile of the sleeve such that relative lateral movement of the sleeve and the opening is substantially prevented.

6. The aircraft assembly according to any one of claims 1 to 5, wherein: The lower surface of the wing includes a fitting, and wherein the sleeve and the at least one fastener engage the fitting.

7. The aircraft assembly according to claim 6, wherein: The wing includes a lower cover, and wherein the fitting is attached to the lower cover.

8. The aircraft assembly according to claim 7, wherein: The fitting is located between the top surface of the engine mounting bracket and the lower cover.

9. The aircraft assembly according to claim 6, wherein: The vertical height of the fitting is less than 100 mm.

10. The aircraft assembly according to any one of claims 1 to 5, wherein: The bushing is a fail-safe bushing.

11. The aircraft assembly according to any one of claims 1 to 5, wherein: The at least one fastener is a fail-safe fastener.

12. An aircraft assembly according to any one of claims 1 to 5, wherein: The diameter of the hole in the structure through which the shank of each said fastener extends is greater than the diameter of the shank of the said fastener.

13. An aircraft comprising an aircraft assembly according to any one of claims 1 to 12.

14. The aircraft of claim 13, further comprising an ultra-high bypass ratio engine mounted on the engine mounting pylon.

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