GB2582603A

GB2582603A - Locking mechanism and actuator

Info

Publication number: GB2582603A
Application number: GB1904243.1A
Authority: GB
Inventors: Horwood Jack; Harding Matt; Morrell Paul
Original assignee: Airbus Operations Ltd
Current assignee: Airbus Operations Ltd
Priority date: 2019-03-27
Filing date: 2019-03-27
Publication date: 2020-09-30
Also published as: GB201904243D0

Abstract

An aircraft has a wing 14 with a wing-tip device 12 moveable between a flight configuration and a ground configuration in which the span of the aircraft wing is reduced, to below an airport gate limit for example. The wing has a rotary actuator 18 which drives a moveable element 22 in a curved path to move the wing-tip device, and a locking device 30 locks the element in position when in the ground configuration. Preferably, the wing-tip, actuator and element all rotate around co-axial axes 16. The moveable element may have an aperture 26 into which a locking pin of the locking device is inserted. The locking device may engage the element and isolate loads on the element exerted by the wing-tip from the rest of the actuator. The rotary actuator may be hydraulic, pneumatic or electrically driven, and may be housed within a wing box of the wing, partially extending beyond the wing box when in the ground configuration. Also claimed is an alternative arrangement utilising a shot bolt assembly which engages an aperture in an extending actuator to hold the wing tip in the ground configuration.

Description

LOCKING MECHANISM AND ACTUATOR

BACKGROUND OF THE INVENTION

100011 There is a trend towards increasingly large passenger aircraft, for which it is desirable to have correspondingly large wing spans. However, the maximum aircraft span is effectively limited by airport operating rules which govern various clearances required when manoeuvring around the airport (such as the span and/or ground clearance required for gate entry and safe taxiway usage).

[0002] Therefore, folding wing tip devices have been introduced into passenger aircraft, where a wing tip device is movable between a flight configuration for use during flight, and a ground configuration for use during ground-based operations. In the ground configuration, the wing tip device is moved away from the flight configuration such that the span of the aircraft wing is reduced, thereby allowing use of existing gates and safe taxiway usage.

[0003] Typically, an actuator is used to move the wing tip device from the flight configuration to the ground configuration, and the actuator holds the wing tip device in the ground configuration during ground based manoeuvres. Stresses and strains during ground based manoeuvres will be passed from the wing tip device through the actuator, thereby potentially damaging the actuator, and/or requiring significant reinforcement of the actuator.

[0004] The present invention seeks to mitigate the above-mentioned problems. Alternatively or additionally the present invention seeks to provide an improved wing tip device and actuation system.

SUMMARY OF THE INVENTION

[0005] The present invention provides an aircraft comprising an aircraft wing, the aircraft wing comprising a fixed wing and a wing tip device at the tip thereof, wherein the wing tip device is configurable between: (i) a flight configuration for use during flight and (ii) a ground configuration for use during ground-based operations, in which ground configuration the wing tip device is moved away from the flight configuration such that -2 -the span of the aircraft wing is reduced, the aircraft wing further comprising a rotary actuator comprising a rotary drive mechanism and a movable element, wherein the rotary drive mechanism is configured to drive the movable element in a curved path to move the wing tip device between the flight configuration and the ground configuration, and a locking device configured to lock the movable element in position when the wing tip device is in the ground configuration.

100061 The wing tip device may move between the flight configuration and ground configuration through rotational movement around an axis, for example, a hinge axis. The rotary drive mechanism may be arranged with an axis of rotation that is parallel to the hinge axis. The rotary drive mechanism may be arranged with an axis of rotation that is parallel to and coincident with the hinge axis. The rotary actuator may be a geared rotary actuator. The rotary actuator may comprise a rack and pinion, for example, with a curved rack.

[0007] The locking device may be configured to mechanically engage the movable element when the wing tip device is in the ground configuration. The locking device may isolate loads on the movable element exerted by the wing tip device from the rest of the actuator. Such an arrangement may allow for an actuator with a lower load rating to be used. The movable element may comprise an aperture, and the locking device may comprise a locking pin which may be extended into the aperture when the wing tip device is in the ground configuration. The aperture may be in the form of a recess or a through-hole. The movable element may comprise a lug and the aperture may be provided in the lug. The movable element may comprise a partial or open lug, or hook, which engages with locking device such that movement away from the ground configuration is prevented. The provision of an open lug or hook may reduce the level of tolerance required when engaging the locking device with the movable element, thus allowing easier locking of the wing tip device in the ground configuration.

[0008] The actuator may be substantially housed within the fixed wing. The fixed wing may comprise a wing box, and the actuator may be substantially housed within the wing box. The actuator may at least partially extend beyond the wing box when the wing tip device is in the ground configuration. The actuator may be substantially housed within the wing tip device. The wing tip device may comprise a wing box, and the actuator may be substantially housed within the wing box. The actuator may at least partially extend beyond the wing box when the wing tip device is in the ground configuration.

[0009] According to a second aspect, the invention provides an aircraft wing comprising a fixed wing and a wing tip device at the tip thereof, wherein the wing tip device is configurable between: (i) a flight configuration for use during flight and (ii) a ground configuration for use during ground-based operations, in which ground configuration the wing tip device is moved away from the flight configuration such that the span of the aircraft wing is reduced, the aircraft wing further comprising a rotary actuator comprising a rotary drive mechanism and a movable element, wherein the rotary drive mechanism is arranged to drive the movable element in a curved path to move the wing tip device between the flight configuration and the ground configuration, and a locking device configured to lock the movable element in position when the wing tip device is in the ground configuration.

[0010] According to a third aspect, the invention provides a method of moving a wing tip device of an aircraft according to the first aspect of the invention from the flight configuration to the ground configuration, the method comprising the steps of: activating the actuator to drive the wing tip device from the flight configuration to the ground configuration, and activating the locking device to lock the actuator in position.

[0011] The actuator may comprise a movable element with an aperture, the locking device may comprise a locking pin, and the step of activating the locking device to lock the actuator may comprise driving the locking pin into the aperture, thereby preventing movement of the movable element. The movable element may comprise a lug and the aperture may be provided in the lug.

100121 According to a fourth aspect, the invention provides a method of moving a wing tip device of an aircraft according to the first aspect from the ground configuration to the flight configuration, the method comprising the steps of: activating the locking device to unlock the actuator, and activating the actuator to drive the wing tip device from the ground configuration to the flight configuration.

[0013] The actuator may comprise a movable element including an aperture, the locking device may comprise a locking pin, and the step of activating the locking device to unlock the actuator may comprise withdrawing the locking pin from the aperture, thereby -4 -allowing movement of the movable element. The movable member may comprise a lug and the aperture may be provided in the lug.

[0014] In embodiments of the present invention, the wing tip device is configurable between: (a) a flight configuration for use during flight and (b) a ground configuration for use during ground-based operations, in which ground configuration the wing tip device is moved away from the flight configuration such that the span of the aircraft wing is reduced. In the flight configuration, the span may exceed an airport compatibility limit. In the ground configuration the span may be reduced such that the span (with the wing tip device in the ground configuration) is less than, or substantially equal to, the airport compatibility limit. The airport compatibility limit is a span limit (for example relating to clearance restrictions for buildings, signs, other aircraft). The compatibility limit is preferably a gate limit.

[0015] The wing tip device may be a wing tip extension; for example the wing tip device may be a planar tip extension. In other embodiments, the wing tip device may comprise, or consist of a non-planar device, such as a winglet.

[0016] In the flight configuration the trailing edge of the wing tip device is preferably a continuation of the trailing edge of the fixed wing. The leading edge of the wing tip device is preferably a continuation of the leading edge of the fixed wing. There is preferably a smooth transition from the fixed wing to the wing tip device. It will be appreciated that there may be a smooth transition, even where there are changes in sweep or twist at the junction between the fixed wing and wing tip device. However, there are preferably no discontinuities at the junction between the fixed wing and wing tip device. The upper and the lower surfaces of the wing tip device may be continuations of the upper and lower surfaces of the fixed wing. The span ratio of the fixed wing relative to the wing tip device may be such that the fixed wing comprises at least 70%, 80%, 90%, or more, of the overall span of the aircraft wing.

[0017] When the wing tip device is in the ground configuration, the aircraft incorporating the wing, may be unsuitable for flight. For example, the wing tip device may be aerodynamically and/or structurally unsuitable for flight in the ground configuration. The aircraft is preferably configured such that, during flight, the wing tip device is not movable to the ground configuration. The aircraft may comprise a sensor for sensing -5 -when the aircraft is in flight. When the sensor senses that the aircraft is in flight, a control system is preferably arranged to disable the possibility of moving the wing tip device to the ground configuration.

[0018] The aircraft is preferably a passenger aircraft. The passenger aircraft preferably comprises a passenger cabin comprising a plurality of rows and columns of seat units for accommodating a multiplicity of passengers. The aircraft may have a capacity of at least 20, more preferably at least 50 passengers, and more preferably more than 50 passengers. The aircraft is preferably a powered aircraft. The aircraft preferably comprises an engine for propelling the aircraft. The aircraft may comprise wing-mounted, and preferably underwing, engines.

[0019] According to yet another aspect, there is provided, an aircraft wing comprising a fixed wing and a foldable wing tip device at the tip thereof, the wing tip device being configurable via activation of a rotary actuator, between a flight configuration and a ground configuration in which the span is reduced below an airport gate limit, wherein the wing comprises a shot bolt assembly for selectively extending a shot bolt through an aperture associated with the rotary actuator, to lock the actuator in a rotated configuration, such that the wing tip device can be held in the ground configuration. [0020] It will of course be appreciated that features described in relation to one aspect of the present invention may be incorporated into other aspects of the present invention. For example, the method of the invention may incorporate any of the features described with reference to the apparatus of the invention and vice versa.

[0021] The term 'or' shall be interpreted as 'and/or' unless the context requires otherwise.

DESCRIPTION OF THE DRAWINGS

[0022] Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings of which: [0023] Figure 1A shows a schematic view of an aircraft wing according to a first embodiment of the invention; -6 - [0024] Figure 1B shows a schematic view of an aircraft according to a second embodiment of the invention; [0025] Figure 2 shows a schematic cross-sectional view of an aircraft wing according to the first embodiment of the invention in a flight configuration; and [0026] Figure 3 shows a schematic cross-sectional view of an aircraft wing as also shown in figure 2, though in the ground configuration.

DETAILED DESCRIPTION

[0027] Figure I A shows a wing 10 comprising a wing tip device 12 and a fixed wing 14. Figure 1B shows an aircraft 100 comprising the wing 10. The wing tip device 12 is configurable between: (i) a flight configuration for use during flight, as shown in figure IB and (ii) a ground configuration for use during ground-based operations, as shown in figure I A, in which ground configuration the wing tip device 12 is moved away from the flight configuration such that the span of the aircraft wing 10 is reduced.

[0028] Figures 2 and 3 show an actuator arrangement according to a first embodiment of the invention. Figure 2 shows the wing tip device 12 in a flight configuration for use during flight. Figure 3 shows the wing tip device 12 in a ground configuration for use during ground-based operations. As can be seen, in figure 3, the wing tip device 12 has been rotated around a hinge axis 16, which causes the wing tip device to move upwards (relative to the ground), thereby reducing the wing span of the aircraft. A rotary actuator 18 is associated with both the fixed wing 14 and the wing tip device 12 to drive and control the movement between the fixed wing 14 and the wing tip device 12. The rotary actuator 18 comprises a rotary drive mechanism 20 and a movable element 22. At least part of the rotary drive mechanism 20 is arranged with the axis of rotation aligned parallel to the hinge axis 16. Rotary movement of the rotary drive mechanism 20 is transferred to the movable element 22, causing the movable element to rotate around the hinge axis 16 in a curved path. Rotation of the rotary drive mechanism 20 in a first direction, when the aircraft is initially in the flight configuration, causes the wing tip device 12 to be driven into a ground configuration. Rotation of the rotary drive mechanism 20 in a second, opposite direction, when the aircraft is in the ground configuration, causes the wing tip device 12 to be driven into the flight configuration. The skilled person will understand that the rotary drive mechanism may be electrically, pneumatically, hydraulically, or mechanically driven.

[0029] The movable element 22 comprises a lug 24 including an aperture 26. The lug 24 is located at the external surface of the movable element 22. M. the flight configuration, the lug 24 does not have any function and the wing tip device 12 is locked in the flight configuration by conventional apparatus. Various such locking apparatus exist and would be known and understood by the skilled person. As such, no further disclosure is required. Once the wing tip device 12 is unlocked from the flight configuration, and as the wing tip device 12 is moved into the ground configuration, the lug 24 is rotated around along with the movable element 22. When in the ground configuration, as shown in figure 3, the lug 24, and specifically the aperture 26, is aligned with a locking mechanism 30, which comprises a locking pin 28 which may be inserted through the aperture 26 such that movement away from the ground configuration is prevented. The skilled person will understand that the locking mechanism 30 may be electrically, pneumatically, hydraulically, or mechanically driven. The locking mechanism 30 may be mechanically attached to one or more of the main load bearing structures of the aircraft wing, in this case the fixed wing 14, such that loads are transferred from the wing tip device 12 directly into the main load bearing structure of the wing when the wing tip device 12 is in the ground configuration.

[0030] Additionally, the insertion of the locking pin 28 through the aperture 26 provides a load path, through which any loads exerted on the wing tip device 12 are passed. Therefore, the engagement of the lug 24 and the locking mechanism 30 when the wing tip device is in the ground configuration acts to isolate the rotary drive mechanism 20. As wing tip loads are not passed onto the rotary drive mechanism 20, the rotary drive mechanism 20 has no role to play in maintaining the wing tip device 12 in the ground configuration. As such, the load capacity of the rotary drive mechanism 20 may not need to be as high as if a locking function were to be provided by the rotary drive mechanism 20. Additionally, the risk of ground loads on the wing tip device damaging the rotary drive mechanism is reduced or eliminated. This may reduce the possibility of ground -8 -damage resulting in the wing tip device being unable to be moved to the flight configuration.

[0031] Whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein. The embodiment has been described with relation to a simple folding wing tip mechanism, but could be equally applicable to rotary wing tip mechanisms, for example where a wing tip device is rotated in an oblique plane around a slew ring. The lug 24 may comprise an open lug, or a hook, which is engagable with the locking mechanism 30. The locking mechanism 30 may be mechanically attached to a substantial portion of the actuator 30. Such an arrangement, where the actuator 18 and locking mechanism 30, are supplied as a modular unit may make it easier to install on an aircraft wing.

[0032] Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments. -9 -

Claims

CLAIMS1. An aircraft comprising an aircraft wing, the aircraft wing comprising a fixed wing and a wing tip device at the tip thereof, wherein the wing tip device is configurable between: (i) a flight configuration for use during flight and (ii) a ground configuration for use during ground-based operations, in which ground configuration the wing tip device is moved away from the flight configuration such that the span of the aircraft wing is reduced, the aircraft wing further comprising a rotary actuator comprising a rotary drive mechanism and a movable element, wherein the rotary drive mechanism is arranged to drive the movable element in a curved path to move the wing tip device between the flight configuration and the ground configuration, and a locking device configured to lock the movable element in position when the wing tip device is in the ground configuration.
2. An aircraft as claimed in claim I, wherein the wing tip device is configured to move between the flight configuration and ground configuration by rotation around a wing fold axis, and the rotary actuator is configured to rotate around an axis co-axial with the wing fold axis.
3. An aircraft as claimed in claim 1 or claim 2, wherein the movable element is arranged to drive the wing tip device between the flight configuration and ground configuration by rotary movement around the wing fold axis.
4. An aircraft as claimed in any preceding claim, wherein the locking device is configured to mechanically engage with the movable element when the wing tip device is in the ground configuration.
5. An aircraft as claimed in claim 4, wherein the locking device isolates loads on the movable element exerted by the wing tip device from the rest of the actuator.
6. An aircraft as claimed in any preceding claim, wherein the movable element comprises an aperture, and the locking device comprises a locking pin configured to be extended into the aperture when the wing tip device is in the ground configuration -10 -
7. An aircraft as claimed in any preceding claim 6, wherein the rotary drive mechanism is hydraulically driven.
8. An aircraft as claimed in any of claims 1 to 6, wherein the rotary drive mechanism is pneumatically driven.
9. An aircraft as claimed in any of claims 1 to 6, where the rotary drive mechanism is electrically driven.
10. An aircraft as claimed in any preceding claim, wherein the actuator is substantially housed within the fixed wing.
11. An aircraft as claimed in claim 10, wherein the fixed wing comprises a wing box, and the actuator is substantially housed within the wing box.
12. An aircraft as claimed in claim 11, wherein the actuator at least partially extends beyond the wing box when the wing tip device is in the ground configuration.
13. An aircraft wing comprising a fixed wing and a wing tip device at the tip thereof, wherein the wing tip device is configurable between: (i) a flight configuration for use during flight and (ii) a ground configuration for use during ground-based operations, in which ground configuration the wing tip device is moved away from the flight configuration such that the span of the aircraft wing is reduced, the aircraft wing further comprising a rotary actuator comprising a rotary drive mechanism and a movable element, wherein the rotary drive mechanism is arranged to drive the movable element in a curved path to move the wing tip device between the flight configuration and the ground configuration, and a locking device configured to lock the movable element in position when the wing tip device is in the ground configuration..
14. A method of moving a wing tip device of an aircraft according to claim 1 from the flight configuration to the ground configuration, the method comprising the steps of: activating the actuator to drive the wing tip device from the flight configuration to the ground configuration, and activing the locking device to lock the actuator n position.
15. A method as claimed in claim 14, wherein the actuator comprises a movable element with an aperture, the locking device comprises a locking pin, and the step of activating the locking device to lock the actuator comprises driving the locking pin into the aperture, thereby preventing movement of the movable element.
16. A method of moving a wing tip device of an aircraft according to claim 1 from the ground configuration to the flight configuration, the method comprising the steps of: activating the locking device to unlock the actuator, and activating the actuator to drive the wing tip device from the ground configuration to the flight configuration.
17. An aircraft wing comprising a fixed wing and a foldable wing tip device at the tip thereof, the wing tip device being configurable via extension of an actuator, between a flight configuration and a ground configuration in which the span is reduced below an airport gate limit, wherein the wing comprises a shot bolt assembly for selectively extending a shot bolt through an aperture associated with the actuator, to lock the actuator in an extended configuration, such that the wing tip device can be held in the ground configuration.