阅读说明：本技术 飞行器机翼、飞行器、成套部件和改变机翼构型的方法 (Aircraft wing, aircraft, kit of parts and method for changing wing configuration ) 是由 本杰明·毕晓普 于 2019-05-29 设计创作，主要内容包括：本发明涉及一种飞行器机翼(1),其包括固定翼(3)和位于固定翼(3)的梢部处的翼梢装置(4),翼梢装置(4)能够相对于固定翼(3)在用于在飞行期间使用的飞行构型(4a)与用于在基于地面的操作期间使用的地面构型(4b)之间旋转,在地面构型中,翼梢装置(4)相对于固定翼(3)旋转,使得机翼(1)的翼展减小。飞行器机翼(1)具有齿轮组件(31),齿轮组件(31)将翼梢装置(4)联接至致动器(30),使得致动器(30)驱动翼梢装置(4)在飞行构型与地面构型之间旋转,该齿轮组件(31)包括蜗杆传动装置(32)。本发明还涉及一种飞行器、飞行器机翼的成套部件和改变飞行器机翼的构型的方法。(The invention relates to an aircraft wing (1) comprising a fixed wing (3) and a wing tip device (4) at the tip of the fixed wing (3), the wing tip device (4) being rotatable relative to the fixed wing (3) between a flight configuration (4a) for use during flight and a ground configuration (4b) for use during ground-based operations, in which ground configuration the wing tip device (4) is rotated relative to the fixed wing (3) such that the span of the wing (1) is reduced. The aircraft wing (1) has a gear assembly (31), the gear assembly (31) coupling the wing tip device (4) to the actuator (30) such that the actuator (30) drives the wing tip device (4) to rotate between a flight configuration and a ground configuration, the gear assembly (31) including a worm drive (32). The invention also relates to an aircraft, a kit of parts for an aircraft wing and a method of changing the configuration of an aircraft wing.)

1. An aircraft wing comprising a fixed wing and a wing tip device at a tip of the fixed wing, the wing tip device being rotatable relative to the fixed wing between a flight configuration for use during flight and a ground configuration for use during ground-based operations, in which ground configuration the wing tip device is rotated relative to the fixed wing such that the wingspan of the aircraft wing is reduced,

Wherein the aircraft wing comprises a gear assembly that couples the wing tip device to an actuator such that the actuator drives the wing tip device to rotate between the flight configuration and the ground configuration,

And wherein the gear assembly comprises a worm drive.

2. An aircraft wing according to claim 1, wherein the wing tip device is rotatably coupled to the fixed wing by a rotary joint, the rotary joint comprising a follower rotationally fixed relative to the wing tip device and a guide rotationally fixed relative to the fixed wing such that when the wing tip device rotates the follower rotates relative to the guide, and wherein the follower or the guide comprises a rack forming part of the gear assembly.

3. An aircraft wing according to claim 2 wherein the follower comprises the rack.

4. An aircraft wing according to claim 2 or 3 wherein the rack is coupled to the output gear of the worm drive via an intermediate drive.

5. An aircraft wing according to claim 2 or 3 wherein the worm drive comprises a worm which meshes with the rack.

6. An aircraft wing according to any preceding claim wherein the worm drive comprises an input gear configured to rotate about an input axis and an output gear configured to rotate about an output axis, and wherein the input axis and the output axis are oriented at an obtuse angle relative to each other.

7. An aircraft wing according to claim 6, wherein the output axis is substantially parallel to the axis of rotation of the wing tip device.

8. An aircraft wing according to any preceding claim wherein the worm drive comprises a worm and a worm wheel.

9. An aircraft wing according to claim 8, wherein the worm is an input gear of the worm drive and the worm gear is an output gear of the worm drive.

10. An aircraft wing according to claim 8 or 9 when dependent on claim 6 or 7 wherein the worm gear comprises helical teeth.

11. an aircraft wing according to any preceding claim wherein the actuator comprises an output shaft which rotates about an axis and is coupled to an input gear of the worm drive to rotate the input gear about an input axis, and wherein the axis of the output shaft of the actuator is offset from the input axis of the input gear of the worm drive.

12. An aircraft wing according to any preceding claim wherein the wing tip device and the fixed wing are separated along an inclined cutting plane passing through the upper and lower surfaces of the aircraft wing, the inclined cutting plane being oriented normal to the axis of rotation of the wing tip device.

13. An aircraft wing according to any preceding claim wherein the worm drive has an output gear configured to rotate about an axis substantially parallel to the axis of rotation of the wing tip device.

14. An aircraft wing according to claim 13 wherein the wing tip device is rotatably coupled to the fixed wing by a slewing ring.

15. An aircraft wing according to any preceding claim wherein the wing tip device is a wing tip extension.

16. An aircraft comprising an aircraft wing according to any preceding claim.

17. A kit of parts for an aircraft wing, the kit comprising a fixed wing and a wing tip device configured for attachment to a tip of the fixed wing such that the wing tip device is rotatable relative to the fixed wing between a flight configuration for use during flight and a ground configuration for use during ground-based operations, in which ground configuration the wing tip device is rotated relative to the fixed wing such that the wingspan of the aircraft wing is reduced,

wherein the kit of parts further comprises an actuator and a gear assembly for coupling the wing tip device to the actuator such that the actuator drives the wing tip device to rotate between the flight configuration and the ground configuration,

And wherein the gear assembly comprises a worm drive.

18. A method of changing the configuration of an aircraft wing, the aircraft wing comprising a fixed wing and a wing tip device at the tip of the fixed wing, the wing tip device being rotatable relative to the fixed wing between a flight configuration for use during flight and a ground configuration for use during ground-based operations, in which ground configuration the wing tip device is rotated relative to the fixed wing such that the wingspan of the aircraft wing is reduced,

Wherein a gear assembly couples the wing tip device to an actuator such that the actuator drives the wing tip device to rotate between the flight configuration and the ground configuration,

And wherein the gear assembly comprises a worm drive and the method comprises using the actuator to rotate the wing tip device between the flight configuration and the ground configuration.

19. A method according to claim 18, wherein the aircraft wing is an aircraft wing according to any of claims 1 to 15.

Technical Field

The present invention relates to an aircraft comprising a foldable wing, and to a foldable wing for use on the aircraft.

Background

There is a trend towards larger and larger passenger vehicles with higher performance efficiency (e.g. reduced fuel consumption), for which it is desirable to have correspondingly large wing spans. However, the maximum aircraft span is actually limited by airport operating regulations governing the various clearances required when maneuvering around the airport (e.g., the span and/or ground clearance required for gate and safety ramp use).

In some proposed designs, an aircraft is provided with a wing which may have a wing tip device that can be folded to reduce the span of the aircraft on the ground (compared to when the aircraft is configured for flight). However, such folding wings are relatively complex to design and build and present a number of design obstacles, particularly as to how the wing tip device is coupled to the actuator used to move the wing tip device between the folded and deployed positions.

The present invention seeks to solve or mitigate at least some of the above problems. Alternatively or additionally, the present invention seeks to provide an improved aircraft wing including a wing tip device that is rotatable relative to a fixed wing. Alternatively or additionally, the present invention seeks to provide an improved aircraft having a wing tip device that is rotatable relative to a fixed wing. Alternatively or additionally, the present invention seeks to provide an improved method of changing the configuration of an aircraft wing between a flight configuration and a ground configuration by means of a rotatable wing tip device.

Disclosure of Invention

according to a first aspect of the invention there is provided an aircraft wing comprising a fixed wing and a wing tip device at the tip of the fixed wing, the wing tip device being rotatable relative to the fixed wing 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 rotated relative to the fixed wing such that the wing span of the wing is reduced, wherein the aircraft wing comprises a gear assembly which couples the wing tip device to an actuator such that the actuator drives the wing tip device to rotate between the flight configuration and the ground configuration, and wherein the gear assembly comprises a worm drive.

This may allow for greater flexibility in the arrangement of the gear assemblies, including greater flexibility in the arrangement of the orientation of the gears of the gear assemblies, which is particularly advantageous when used to couple a wing tip device to an actuator, as the space to accommodate such gear assemblies is limited. Furthermore, the movement of the wing tip device as it rotates between the flight configuration and the ground configuration can be relatively complex. The use of a worm drive may allow for a relatively simple gear assembly (discussed further below).

optionally, the wing tip device is rotatably coupled to the fixed wing by a rotational joint comprising a follower rotationally fixed relative to the wing tip device and a guide rotationally fixed relative to the fixed wing, such that when the wing tip device rotates, the follower rotates relative to the guide.

Optionally, the follower comprises a first ring and the guide comprises a second ring, the first and second rings being concentric. Preferably, the follower is located radially outwardly of the guide. Alternatively, the follower may be located radially inward of the guide.

the rotary joint may comprise a slew ring. In this regard, one of the first and second rings may form an inner race and the other of the first and second rings may form an outer race.

The follower or guide may comprise a rack, the rack forming part of a gear assembly. Preferably, the follower comprises said rack.

Optionally, a rack couples the wing tip device to the worm drive. In an embodiment of the invention, a rack couples the wing tip device to the output gear of the worm drive.

Optionally, the worm drive comprises an input gear configured to rotate about an input axis and an output gear configured to rotate about an output axis. In an embodiment of the present invention, the input gear and the output gear are meshed with each other such that rotation of the input gear rotates the output gear (and rotation of the output gear rotates the input gear).

The worm drive may include a worm and a worm wheel. It will be appreciated that the worm is a gear in the form of a screw and the worm wheel is a gear engaged with the worm. In this regard, the teeth of the worm wheel mesh with the screw of the worm such that rotation of the worm rotates the worm wheel (and rotation of the worm wheel rotates the worm).

In an embodiment of the invention, the worm comprises a thread, preferably an external thread. Preferably, the thread is helical.

Preferably, the worm is an input gear and the worm gear is an output gear. Alternatively, the worm gear may be an input gear and the worm may be an output gear.

The rack may be coupled to an output gear of the worm drive via at least one intermediate drive. In this regard, the rack may be coupled to the output gear of the worm drive via at least one idler gear.

This is advantageous because it may allow greater freedom in the positioning of the output gear of the worm drive. In this regard, it may allow the worm drive to be positioned further inboard (i.e., toward the root of the aircraft wing) and further aft (i.e., toward the trailing edge of the aircraft wing), where there is typically more space to accommodate the worm drive.

It should be understood that an idler gear is a transmission that is located between two or more transmissions (e.g., gears, racks, etc.) and couples the transmissions (by meshing with the transmissions). The idler may provide spacing between the transmissions coupled together by it, allowing one or more of the transmissions (coupled by it) to be reduced in size.

The idler gear may be located between and mesh with a transmission mounted on the output shaft of the worm drive so as to rotate with the output shaft and the rack.

Alternatively, the worm of the worm drive may mesh with the rack. In this case, the rack may form the output gear of the worm drive, i.e. the worm drive may comprise a worm and a rack, wherein the worm forms the input gear of the worm drive and the rack comprises the output gear of the worm drive. It will also be appreciated that in this case the rack forms a worm gear (and may have any of the features described for the worm gear).

Preferably, the input axis and the output axis are oriented at an obtuse angle relative to each other.

Preferably, the obtuse angle is greater than or equal to 95 ° and less than or equal to 105 °, more preferably, greater than or equal to 100 ° and less than or equal to 105 °.

In an embodiment of the invention, the input axis and the output axis are oriented at an obtuse angle relative to each other when viewed in a direction perpendicular to a plane parallel to the input axis and the output axis. It will be appreciated that the projection of the input and output axes in a plane forms an obtuse angle. In this regard, the output axis is inclined outwardly away from the normal to the input axis. The output axis is inclined such that a direction along the output axis from the intersection of the input axis and the output axis towards the follower has a component in a direction along the input axis away from the end of the input shaft closest to the actuator.

Preferably, the output axis is substantially parallel to the axis of rotation of the wing tip device.

This may allow the subsequent transmissions in the gear assembly (i.e. the transmissions of the gear assembly between the output gear of the worm drive and the wing tip device) to have a relatively simple arrangement, for example with their rotational axes substantially parallel to the rotational axis of the wing tip device, thereby providing a relatively simple meshing arrangement between each of these transmissions.

Preferably the transmissions of the gear assembly between the output gear of the worm drive and the wing tip device each have an axis of rotation substantially parallel to the axis of rotation of the wing tip device.

The worm gear preferably includes helical teeth.

Optionally, the actuator comprises an output shaft that rotates about an axis and is coupled to the input gear of the worm drive to rotate the input gear about the input axis, and wherein the axis of the output shaft of the actuator is offset from the axis of the input gear of the worm drive.

This is advantageous as it may provide greater flexibility in the location where the actuator can be located. Additionally, one or more transmissions coupling the output shaft of the actuator to the input gear of the worm drive may provide additional gear reduction.

Preferably, the output shaft of the actuator is coupled to the input gear of the worm drive via a transmission. In this regard, it is preferred that a gear is mounted on the output shaft of the actuator, the gear meshing with a gear coupled to an input gear of the worm drive, such that rotation of the actuator rotates the input gear of the gear. The input gear of the worm drive may be rotationally fixed relative to the gear.

Preferably, the axis of the output shaft of the actuator is parallel to the input axis of the worm drive.

The wing tip device is rotatable about an axis of rotation between a flight configuration and a ground configuration. The orientation of the axis is preferably such that the span of the aircraft wing is reduced as the wing tip device rotates about the axis from a flight configuration to a ground configuration.

Optionally, the wing tip device and the fixed wing are separated along inclined cutting surfaces passing through the upper and lower surfaces of the wing, the inclined cutting surfaces being oriented orthogonal to the axis of rotation of the wing tip device.

The axis of rotation is oriented normal to the main cutting plane. The main cutting plane is preferably inclined. The cutting plane preferably extends through the upper and lower surfaces of the wing. The distance along the upper surface of the wing from the root of the wing to the cutting plane (i.e. to the location where the cutting plane intersects the upper surface) may be less than the distance along the lower surface of the wing from the root of the wing to the cutting plane (i.e. to the location where the cutting plane intersects the lower surface). Thus, the cutting plane may form an undercut (undercut) with respect to the stationary wing. In other embodiments, the distance along the upper surface of the wing from the root of the wing to the cutting plane (i.e., to the location where the cutting plane intersects the upper surface) may be greater than the distance along the lower surface of the wing from the root of the wing to the cutting plane (i.e., where the cutting plane intersects the lower surface). Thus, the cutting plane may form an undercut (undercut) with respect to the stationary wing.

The main cutting plane is preferably an imaginary plane separating the fixed wing from the wing tip device (e.g. a cutting plane generated during the design phase of the wing). It should be understood that the cutting plane does not necessarily represent itself as a physical, planar surface throughout the depth of the entire wing. The main cutting plane will be easily identifiable to the skilled person. The main cutting plane may be the plane in which the wing tip device rotates. Some embodiments of the invention may comprise a support for supporting rotation of the wing tip device, such as a slewing ring. The support may be concentric with the axis of rotation. The primary cutting plane may extend through the thickness of the support and generally through an intermediate thickness of the support (i.e., the intermediate thickness of the support is coplanar with the primary cutting plane).

The axis of rotation may be oriented at an angle (i.e., not including parallel or perpendicular) to the longitudinal direction. Preferably, the axis is at an angle to the transverse direction (i.e., not including parallel or perpendicular). Preferably, the axis is at an angle to the vertical (i.e., not including parallel or perpendicular). The vertical direction, the longitudinal direction and the transverse direction may be perpendicular to each other. In some embodiments, the longitudinal direction, the lateral direction, and the vertical direction may be in an absolute frame of reference (i.e., the longitudinal direction is a fore-aft direction, the lateral direction is a port-starboard direction, and the vertical direction is perpendicular to the ground). The longitudinal direction may be a chordwise direction; the lateral direction may be a spanwise direction. In other embodiments, it may be appropriate to use the longitudinal, transverse and vertical directions in the local reference frame of the wing. For example, for a swept wing, the longitudinal direction may instead be along the length of the wing, and the transverse direction may be along the width of the wing (i.e., measured perpendicular to the longitudinal direction from the leading edge to the trailing edge). Alternatively or additionally, for a wing with a dihedral angle, the vertical direction may be perpendicular to the plane of the wing. In all cases, the cutting plane/axis is oriented such that the span of the wing decreases as the wing tip device rotates about the axis. The forward and aft portions of the axis of rotation may be determined by reference to a boundary defined by an axis perpendicular to the longitudinal axis of the aircraft and intersecting the axis of rotation. All points towards the front of the aircraft relative to the boundary may be considered to be the front of the axis of rotation and all points towards the rear of the aircraft relative to the boundary may be considered to be the rear of the axis of rotation. Alternatively, the forward and aft positions may be determined in a local frame of reference of the wing. The boundary may be aligned in a manner intersecting the axis of rotation and parallel to the leading edge of the airfoil. The aircraft wing may include a spar extending in a generally spanwise direction, and the boundary may be aligned to intersect the axis of rotation and be parallel to the spar.

preferably, the wing tip device is rotatable about a single axis of rotation. For example, the rotation of the wing tip device is preferably not the result of compound rotation (i.e. a net rotation formed by a plurality of individual rotations about individual axes).

the axis is preferably at an angle of less than 45 degrees and more preferably less than 25 degrees to the vertical. The axis may be at an angle of 15 degrees to the vertical axis. The invention has been found to be particularly beneficial in embodiments in which the axis is at a relatively small angle to the vertical, since the orientation of the axis results in a shallower cutting plane and the interface area between the fixed wing and the wing tip device may therefore be relatively large.

According to a second aspect of the invention, there is provided an aircraft wing comprising a fixed wing and a wing tip device at the tip of the fixed wing, the wing tip device is rotatable relative to the fixed wing between a flight configuration for use during flight and a ground configuration for use during ground-based operations, in a ground configuration, the wing tip device is rotated relative to the fixed wing such that the span of the wing is reduced, the wing tip device is rotatably coupled to the fixed wing by a slewing ring, the aircraft wing comprises a gear assembly, the gear assembly coupling the wing tip device to the actuator, such that the actuator drives rotation of the wing tip device between the flight configuration and the ground configuration, wherein the gear assembly comprises a worm drive having an output gear configured to rotate about an axis which is substantially parallel to the axis of rotation of the wing tip device.

The aircraft wing of the second aspect of the invention may have any of the features of the aircraft wing of the first aspect of the invention.

According to a third aspect of the invention there is provided an aircraft comprising an aircraft wing according to the first or second aspect of the invention.

According to a fourth aspect of the invention there is provided a kit of parts for an aircraft wing, the kit of parts comprising a fixed wing and a wing tip device configured for attachment to the tip of the fixed wing such that the wing tip device is rotatable relative to the fixed wing between a flight configuration for use during flight in which the wing tip device is rotated relative to the fixed wing such that the span of the wing is reduced, and a ground configuration for use during ground-based operations, wherein the kit of parts further comprises an actuator and a gear assembly for coupling the wing tip device to the actuator such that the actuator drives the wing tip device to rotate between the flight configuration and the ground configuration, and wherein the gear assembly comprises a worm drive.

According to a fifth aspect of the invention there is provided a method of changing the configuration of an aircraft wing, the aircraft wing comprising a fixed wing and a wing tip device at the tip of the fixed wing, the wing tip device being rotatable relative to the fixed wing 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 rotating relative to the fixed wing such that the span of the wing is reduced, wherein a gear assembly couples the wing tip device to an actuator such that the actuator drives the wing tip device to rotate between the flight configuration and the ground configuration, and wherein the gear assembly comprises a worm drive, and the method comprises rotating the wing tip device between the flight configuration and the ground configuration by use of the actuator.

the aircraft wing in the method of the fifth aspect of the invention may have any of the features of the aircraft wing of the previous aspect of the invention.

Optionally, the aircraft and/or the rotary joint are arranged such that a majority of aerodynamic and inertial loads on the wing tip device during use of the aircraft are transferred to the fixed wing via the rotary joint. Optionally, substantially all aerodynamic and inertial loads on the wing tip device during use of the aircraft are transferred to the fixed wing via the rotary joint.

The wing tip device and the fixed wing may be separated along an inclined cutting plane through the upper and lower surfaces of the wing, the inclined cutting plane being oriented orthogonal to the axis of rotation of the wing tip device. The inclined plane and the axis of rotation may be such that the fixed wing and wing tip device do not collide when rotating between the flight configuration and the ground configuration. An example of a wing tip device that can be rotated in this manner is shown in WO 2015/150835. Embodiments of the invention have been found to be particularly effective in relation to this type of moveable wing tip device, as limited internal space is available during assembly.

The orientation of the axis of rotation of the wing tip device is preferably such that the span of the aircraft wing is reduced as the wing tip device rotates about the axis of rotation from a flight configuration to a ground configuration.

The cutting plane is inclined. The distance along the upper surface of the wing from the root of the wing to the cutting plane (i.e. to the location where the cutting plane intersects the upper surface) may be less than the distance along the lower surface of the wing from the root of the wing to the cutting plane (i.e. to the location where the cutting plane intersects the lower surface). Thus, the cutting plane may form an undercut with respect to the stationary vane. In other embodiments, the distance along the upper surface of the wing from the root of the wing to the cutting plane (i.e., to the location where the cutting plane intersects the upper surface) may be greater than the distance along the lower surface of the wing from the root of the wing to the cutting plane (i.e., where the cutting plane intersects the lower surface). Thus, the cutting plane may form an undercut with respect to the stationary vane.

Preferably, the inclined cutting plane is an imaginary plane separating the fixed wing and the wing tip device (e.g. a cutting plane formed during the design phase of the wing). It should be understood that the cutting plane does not necessarily represent itself as a physical, planar surface throughout the depth of the entire wing.

The axis of rotation may be oriented at an angle (i.e., not including parallel or perpendicular) to the longitudinal axis. Preferably, the axis is at an angle to the transverse direction (i.e., not including parallel or perpendicular). Preferably, the axis is at an angle to the vertical (i.e., not including parallel or perpendicular). The vertical direction, the longitudinal direction and the transverse direction may be perpendicular to each other. In some embodiments, the longitudinal direction, the lateral direction, and the vertical direction may be in an absolute frame of reference (i.e., the longitudinal direction is a fore-aft direction, the lateral direction is a port-starboard direction, and the vertical direction is perpendicular to the ground). The longitudinal direction may be a chordwise direction; the lateral direction may be a spanwise direction. In other embodiments, it may be appropriate to use the longitudinal, transverse and vertical directions in the local reference frame of the wing. For example, for a swept wing, the longitudinal direction may instead be along the length of the wing, and the transverse direction may be along the width of the wing (i.e., measured perpendicular to the longitudinal direction from the leading edge to the trailing edge). Alternatively or additionally, for a wing with a dihedral angle, the vertical direction may be perpendicular to the plane of the wing.

preferably, the wing tip device is rotatable about a single axis of rotation. For example, the rotation of the wing tip device is preferably not the result of compound rotation (i.e. a net rotation formed by a plurality of individual rotations about individual axes).

The angle is preferably an oblique angle. The axis is preferably at an angle of less than 45 degrees and more preferably less than 25 degrees to the vertical. The axis may be at an angle of 15 degrees to the vertical axis. The invention has been found to be particularly beneficial in embodiments in which the axis is at a relatively small angle to the vertical, since the orientation of the axis results in a shallower cutting plane and the interface area between the fixed wing and the wing tip device may therefore be relatively large.

In flight configurations, the span may exceed airport compatibility limits. In ground configurations, the span may be reduced such that the span (with the wing tip device in ground configuration) is less than or approximately equal to airport compatibility limits. Airport compatibility limitations are span limitations (e.g., related to clearance constraints for buildings, signs, other aircraft, etc.). The compatibility limit is preferably a threshold limit.

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.

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. Preferably there is a smooth transition from the fixed wing to the wing tip device. It will be appreciated that even in the event of a change in sweep or twist at the interface between the fixed wing and the wing tip device, there may still be a smooth transition. However, there is preferably no discontinuity at the interface between the fixed wing and the wing tip device. The upper and lower surfaces of the wing tip device may be a continuation 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 70%, 80%, 90% or more of the total span of the aircraft wing.

An aircraft incorporating a wing may not be suitable for flight when the wing tip device is in the ground configuration. The aircraft is preferably configured such that the wing tip device cannot be moved to the ground configuration during flight. The aircraft may include sensors for sensing when the aircraft is in flight. When the sensor senses that the aircraft is in flight, the control system is preferably arranged such that there is no possibility of moving the wing tip device to the ground configuration.

The aircraft may be any aircraft, such as a manned aircraft or an unmanned aircraft. More preferably, the aircraft is a passenger aircraft. The passenger aircraft preferably comprises a passenger cabin comprising a plurality of rows and columns of seating units for accommodating a plurality of passengers. The aircraft may be accommodated by at least 20, more preferably by at least 50, and more preferably by 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 an engine mounted to the wing and preferably below the wing.

Of course, it will be appreciated that features described with reference to one aspect of the invention may be incorporated into other aspects of the invention. For example, the method of any aspect of the invention may incorporate any feature described with reference to the apparatus of any aspect of the invention, and vice versa.

Other preferred and advantageous features of the invention will be apparent from the following description.

Drawings

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

Figure 1a shows a perspective view of a swept wing of a passenger aircraft according to a first embodiment of the invention, wherein the wing tip device of the wing is shown in flight configuration (shown in dashed lines) and in ground configuration (shown in solid lines);

Figure 1b shows a front view of the passenger carrier aircraft with the wing tip device in a flight configuration;

Figure 2 shows a plan view of an end region of the wing of figure 1a when the wing tip device is in a flight configuration, the plan view showing a rotary joint of an aircraft wing and wherein, for illustration purposes, part of the wing skin of the wing tip device and fixed wing is omitted;

Figure 3a shows a schematic perspective view of the aircraft wing shown in figures 1 to 3 (with the upper skin omitted to show the wing and some of the internal structure of the wing tip device), with the wing tip device in a flight configuration;

Figure 3b shows a view corresponding to the view of figure 3a, but in figure 3b the wing tip device is rotated towards the ground configuration;

Figure 4 shows a perspective view of the region of the rotary joint coupling the wing tip device to the fixed wing;

Fig. 5 shows an enlarged view of the region G in fig. 4, wherein the housing of the worm drive is omitted for illustration purposes;

Figure 6 is a view of the rotary joint of the aircraft wing and a portion of the actuator and gear assembly of the aircraft wing shown in figures 1 to 5 taken along the axis of rotation of the wing tip device;

FIG. 7 is a view of a portion of the rotary joint, actuator and gear assembly of the aircraft wing shown in FIG. 6 taken along the axis of the output shaft of the motor;

FIG. 8 illustrates a side view of a portion of the rotary joint, actuator and gear assembly of the aircraft wing illustrated in FIGS. 6 and 7;

fig. 9 shows an enlarged view of region H in fig. 8, wherein the worm of the worm drive is omitted for illustrative purposes; and

Fig. 10a to 10c show perspective views of a part of a rotary joint of an aircraft wing according to a second, third and fourth embodiment of the invention, respectively.

Detailed Description

Fig. 1a is a perspective view of an aircraft wing 1 of an aircraft 2 according to a first embodiment of the invention. The aircraft wing 1 comprises a fixed wing 3 and a wing tip device 4.

The aircraft 2 is a passenger aircraft comprising a passenger cabin comprising a plurality of rows and columns of seating units for accommodating a plurality of passengers, in this case more than 50 passengers. The aircraft has a pair of wings 1. The aircraft is a powered aircraft and includes an engine 92 mounted below the wing 1 for propelling the aircraft 2.

The fixed wing 3 extends from the fuselage of the aircraft in a spanwise direction outwardly from a root 20 to a tip 21. The fixed wing 3 also extends in a chordwise direction from a leading edge 5 to a trailing edge 7.

The wing tip device 4 is located at the outboard tip 21 of the fixed wing 3. In the embodiment described the wing tip device 4 is in the form of a planar wing tip extension, but the invention is applicable to other types of wing tip devices (e.g. non-planar wing tip devices such as winglets).

the wing tip device 4 is movable between a flight configuration 4a (shown in dotted lines in figure 1 a) and a ground configuration 4b (shown in solid lines in figure 1 a). When the wing tip device 4 is in the flight configuration, it extends in a spanwise direction outwardly from an inboard end 24 at the tip 21 of the fixed wing 3 to a tip 25. The wing tip device 4 also extends in a chordwise direction from the leading edge 5 'to the trailing edge 7'.

In the flight configuration, the leading edge 5 'and the trailing edge 7' of the wing tip device 4 are continuations of the leading edge 5 and the trailing edge 7 of the fixed wing 3. Furthermore, the upper and lower surfaces of the wing tip device 4 are a continuation of the upper and lower surfaces of the fixed wing 3. Thus, there is a smooth transition from the fixed wing 3 to the wing tip device 4.

It will be appreciated that even in the event of a change in sweep or twist at the interface between the fixed wing 3 and the wing tip device 4, there may still be a smooth transition. However, there is preferably no discontinuity at the junction between the fixed wing 3 and the wing tip device 4.

the wing tip device 4 is arranged in a flight configuration for flight. Thus, in the flight configuration, the wing tip device 4 increases the span of the aircraft (thereby providing beneficial aerodynamic effects such as a reduction in the component of induced drag and an increase in lift). In principle, it is desirable to maintain this large span at all times and to have only large stationary wings. However, the maximum aircraft span is actually limited by airport operating regulations governing the various clearances required when maneuvering around the airport (e.g., the span and/or ground clearance required for gate and safety ramp use). In this regard, in flight configurations, the span may exceed airport compatibility door limits. Thus, the wing tip device 4 can be moved to a ground configuration for use when the aircraft is on the ground.

In the ground configuration 4b, the wing tip device 4 is folded from the flight configuration described above such that the wing tip device 4 rotates rearwardly (aft) sweeping in an arc. When the wing tip device 4 is in the ground configuration, the span of the wing 1 is reduced (compared to when the wing tip device 4 is in the flight configuration) and the aircraft 2 therefore conforms to the airport gaps etc. described above. In this regard, in ground configurations, the span may be reduced such that the span (with the wing tip device in ground configuration) is less than or substantially equal to the airport compatibility door limit.

When the wing tip device 4 is in the ground configuration, the aircraft 2 incorporating the wing 1 is not suitable for flight. The aircraft 2 is configured such that the wing tip device 4 cannot be moved to the ground configuration during flight. The aircraft 2 includes sensors for sensing when the aircraft is in flight. When the sensor senses that the aircraft 2 is in flight, the control system is arranged such that there is no possibility of moving the wing tip device 4 to the ground configuration.

Referring to fig. 2, an aircraft wing 1 comprises a rotary joint 10. The swivel joint 10 rotatably couples the wing tip device 4 to the fixed wing 3 to allow the wing tip device 4 to rotate about the axis of rotation B between the flight configuration 4a and the ground configuration 4B.

With reference to figures 3a and 3b, to achieve the above described movement, the wing tip device 4 and the fixed wing 3 are separated along an inclined cut plane 13 passing through the upper and lower surfaces of the wing 1. The axis of rotation B of the wing tip device 4 extends in a direction perpendicular to the inclined cutting plane 13. The axis of rotation B is oriented at an acute angle relative to all three mutually perpendicular axes X, Y and Z (i.e., chordwise, spanwise, and vertically).

The inclined plane 13 and the axis of rotation B are such that the fixed wing 3 and the wing tip device 4 do not collide when the wing tip device 4 rotates between the flight configuration and the ground configuration. An example of a wing tip device 4 that may be rotated in this manner is shown in WO 2015/150835, the contents of which are incorporated herein by reference.

The aircraft 2 is arranged such that substantially all aerodynamic and inertial loads on the wing tip device 4 during use of the aircraft are transferred to the fixed wing 3 via the rotary joint 10.

the rotary joint 10 is in the form of a slew ring comprising an outer race 8 and an inner race 9 (see figure 2). Each of the inner race 9 and the outer race 8 is a substantially circular ring. The inner race 9 is concentrically mounted within the outer race 8, the outer race 8 being arranged to rotate about the inner race 9.

The inner race 9 is integrated with the stationary vane 3 such that the inner race 9 is rotationally fixed relative to the stationary vane 3.

The outer race 8 is rotationally fixed to the wing tip device 4 such that the wing tip device 4 rotates with the outer race 8 about the axis of rotation B between the flight configuration and the ground configuration. In this regard, the outer race 8 is attached to an inboard rib of the wing tip device 4.

The inner race 9 is nested within the outer race 8 and is concentric with the outer race 8. In this regard, the outer race 8 and the inner race 9 are both centred on the axis of rotation B of the wing tip device 4.

The outer race 8 is arranged to rotate about an axis of rotation B. Between the inner race 9 and the outer race 8, i.e. between the radially outer surface of the inner race 9 and the radially inner surface of the outer race 8, bearing elements in the form of steel cylindrical rings (not shown) provided with a low friction polymer coating are provided to support the outer race 8 in rotation about the inner race 9. In this regard, the outer race 8 functions as a follower, and the inner race 9 functions as a guide to guide the rotation of the outer race 8. It will be appreciated that any suitable bearing arrangement may be used.

The aircraft wing 1 further comprises a prime mover 30 and a gear assembly 31, the gear assembly 31 coupling the prime mover 30 to the wing tip device 4 to rotate the wing tip device 4 between the flight configuration 4a and the ground configuration 4 b.

In more detail, the prime mover 30 is an actuator in the form of an electric motor 30. The electric motor 30 is configured to drive an output shaft 40 about a rotational axis a (see fig. 5).

An actuator output gear in the form of a gear 41 is mounted on the output shaft 40 and is rotationally fixed to the shaft so that it rotates with the shaft 40.

The worm drive 32 comprises an input gear in the form of a worm 34 (see fig. 8) and an output gear in the form of a worm wheel 35 (see fig. 5). The worm 34 and the worm wheel 35 are accommodated in a housing 49, and the housing 49 is fixed to the casing of the motor 30. In this regard, the housing 49 is rotationally fixed. An electric motor 30 and a gear assembly 31 are mounted to the fixed wing 3.

The worm 34 is a transmission in the form of a screw provided with an external helical thread 45.

The worm gear 35 is in the form of a gear wheel provided with helical teeth 38 distributed around its circumference. The teeth 38 of the worm wheel 35 mesh with the threads of the worm 34 such that rotation of the worm 34 rotates the worm wheel 35 (and rotation of the worm wheel 35 rotates the worm 34).

A coupling gear 44 in the form of a gear wheel meshes with the actuator output gear 41. The coupling gear 44 is fixed to one end of the worm 34 such that rotation of the coupling gear 44 by the prime mover 30 (via the actuator output gear 41) rotates the worm 34 about an axis of rotation C (on the fixed shaft 50) which will be referred to as the input axis C (see fig. 8).

The worm 34 is rotatably mounted in the housing by first and second bearing assemblies disposed at opposite axial ends of the worm 34. Fig. 7 shows a cross-sectional view of the second bearing assembly. The first bearing assembly is not shown in the drawings, but it will be appreciated that it is identical to the second bearing assembly, but is provided at the opposite axial end of the worm 34, i.e. adjacent the coupling gear 44. Each bearing assembly comprises an inner race 61 and an outer race 62 with a plurality of rolling bearing elements (not shown) disposed between the inner and outer races 61, 62. The inner race 61 is rotationally fixed to the worm (i.e., the cylindrical outer surface of the worm 34 on which the helical thread 45 is mounted), and the outer race 62 is rotationally fixed to the radially inner surface of the housing 49.

The input axis C and the rotation axis a of the output shaft 40 of the electric motor 30 are substantially parallel to each other (see fig. 9). Further, the input axis C and the rotational axis a of the output shaft 40 of the prime mover 30 are offset from each other, i.e., they are not coaxial with each other. In this regard, the use of the actuator output gear 41 and the coupling gear 44 allows the input axis C of the worm drive 32 to be offset from the output shaft 40 of the electric motor 30.

This is advantageous because it provides greater flexibility (e.g., relatively more posteriorly) in the location where the electric motor 30 can be positioned. In addition, this provides an additional gear reduction (between the electric motor 31 and the wing tip device 4).

The worm wheel 35 is fixedly mounted on an output shaft 39 (of the worm drive 32) such that the worm wheel 35 and the output shaft 39 rotate about an axis D, which will be referred to as the output axis D.

Thus, the worm 34 engages the worm gear 35 such that rotation of the worm 34 (about the input axis C) rotates the worm gear 35 (about the output axis D).

Unlike conventional worm drives, whose input and output axes are perpendicular to each other, the input and output axes C, D are inclined at an obtuse angle θ relative to each other.

In this regard, the input axis C and the output axis D are oriented at an obtuse angle θ relative to each other when viewed along a direction perpendicular to a plane P (see fig. 9) parallel to the input axis C and the output axis D. It will be appreciated that the projections of the input and output axes in the plane P form an obtuse angle θ. The output axis D is inclined outboard (i.e. towards the tip of the wing tip device 4 when in the flight configuration) away from the normal N to the input axis C.

In this regard, the output axis D is inclined relative to the normal N such that a direction along the output axis D from the intersection of the input axis C and the output axis D toward the outer race 8 has a component in a direction along the input axis C away from the end of the worm 34 at which the coupling gear 44 is disposed.

In the presently described embodiment, the obtuse angle θ is 102.5 °.

The output axis D is substantially parallel to the axis of rotation B of the wing tip device 4. This may allow a relatively simple arrangement of the subsequent transmission in the gear assembly 31 (i.e. the transmission of the gear assembly 31 between the worm wheel 35 and the wing tip device 4). In this regard, the gear 42, the idler gear 33 and the rack 43 (see below) are allowed to have respective axes of rotation that are substantially parallel to the axis of rotation B of the wing tip device 4, thereby providing a relatively simple meshing arrangement between each of these transmissions.

To accommodate the obtuse angular orientation of the output axis D, the teeth 38 of the worm gear 35 are helical (see fig. 9), i.e., the teeth 38 each describe the shape of a portion of a helix extending about the axis of rotation of the worm gear 35.

A gear 42 is fixedly mounted on the output shaft 39 of the worm drive 32 at an opposite end of the worm wheel 35 for rotation with the output shaft 39.

A part of the outer periphery of the outer race 8 is provided with a plurality of teeth distributed in the circumferential direction to form a rack 43.

The idler gear 33 is in the form of a gear and is mounted on a rotatable shaft for rotation about an axis. The idle gear 33 is disposed between the rack gear 43 and the pinion gear 42, and the teeth of the idle gear 33 engage with the teeth of the rack gear 43 and the pinion gear 42 to rotatably couple them together.

The idler gear 33 has the advantage of allowing a greater freedom of positioning of the output shaft 39 of the worm drive 32. In this regard, this allows the worm drive 32 to be positioned further inboard and further aft, where there is typically more room to accommodate the worm drive 32.

Accordingly, the electric motor 30 is coupled to the outer race 8 through a gear assembly 31 to rotate the outer race 8, the gear assembly 31 including an actuator output gear 41, a coupling gear 44, a worm 34, a worm wheel 35, a gear 42, an idler gear 33, and a rack 43.

In this regard, rotation of the electric motor 30 rotates the actuator output gear 41, the actuator output gear 41 rotates the coupling gear 44, the coupling gear 44 rotates the worm 34, the worm 34 rotates the worm wheel 35, the worm wheel 35 rotates the gear 42, the gear 42 rotates the idle gear 33, and the idle gear 33 rotates the rack 43.

As the outer race 8 is fixed to the inboard rib 34 of the wing tip device 4, this in turn rotates the wing tip device 4 about the axis of rotation B between the flight configuration 4a and the ground configuration 4B. The electric motor 30 and gear assembly 31 are arranged to rotate the outer race 8 in both rotational directions about axis B (i.e. clockwise and anticlockwise) to rotate the wing tip device 4 from the flight configuration to the ground configuration and vice versa.

The gear assembly 31 is a reduction transmission. In this regard, the gear assembly 31 is configured to convert the high speed low torque input of the electric motor 30 into a low speed high torque of the wing tip device 4 (it should be understood that the terms "high" and "low" are used with respect to each other). The input-to-output gear ratio of the transmission 31 is 292.4:1, i.e. the electric motor 30 must rotate 292.4 times to make the outer race 8 rotate one full revolution. Conversely, for each revolution of the electric motor 30, the outer race 8 rotates 0.00342 turns, corresponding to 1.23 °.

The rotary joint 10 further comprises a locking mechanism assembly (not shown) configured to selectively lock the rotary joint 10 such that the wing tip device 4 is locked in either the flight configuration 4a or the ground configuration 4 b.

referring to fig. 10a, there is shown a portion of a rotary joint 110 of an aircraft wing according to a second embodiment of the invention. The second embodiment of the present invention is the same as the first embodiment of the present invention except for the differences described below. Corresponding features have been given corresponding reference numerals increased by 100.

the aircraft wing (and rotary joint 110) of the second embodiment is the same as the aircraft wing (and rotary joint) of the first embodiment, except that the worm 134 directly engages with the rack (not visible in figure 10 a) of the outer race 8 to rotate the outer race 8 (between the flight configuration and the ground configuration). In this case, the worm 134 forms the input gear of the worm drive and the rack forms the output gear of the worm drive.

in this regard, in this embodiment, the worm wheel 135, the output shaft 139, the gear 142 and the idler wheel 133 are not present, but the teeth of the worm 134 instead directly engage with the teeth of the rack.

Fig. 10b shows a part of a rotary joint 210 of an aircraft wing according to a third embodiment of the invention. The third embodiment of the present invention is the same as the second embodiment of the present invention except for the differences described below. Corresponding features are given corresponding reference numerals increased by 100 (with respect to the reference numerals of the second embodiment).

The third embodiment of the present invention is the same as the second embodiment of the present invention except that the worm 234 and the rack are located at a different circumferential position (about the rotation axis B) from that in the second embodiment.

Referring to fig. 10c, a portion of a rotary joint 310 of an aircraft wing according to a fourth embodiment of the invention is shown. The fourth embodiment of the present invention is the same as the second embodiment of the present invention except for the differences described below. Corresponding features are given corresponding reference numerals increased by 200 (with respect to the reference numerals of the second embodiment).

the aircraft wing (and rotary joint 310) of the fourth embodiment is the same as the aircraft wing (and rotary joint) of the second embodiment, except that the inner race 309 is rotationally fixed relative to the wing tip device such that the inner race 309 rotates with the wing tip device and the outer race 308 is fixed to the fixed wing. Thus, in this embodiment, the inner race 309 functions as a follower and the outer race 308 functions as a guide to guide the rotation of the inner race 309.

The splines (not shown) are provided on an annular flange 370, the annular flange 370 extending axially from the inner race 309 below the lower surface of the outer race 308.

As in the second and third embodiments, the worm 334 directly engages with the rack. However, in this embodiment, this rotates the inner race 309 to rotate the wing tip device.

While the invention has been described and illustrated with reference to specific embodiments, those skilled in the art will appreciate that the invention lends itself to many different variations not specifically illustrated herein.

For example, in the illustrated embodiment, the worm is the input gear and the worm gear is the output gear. Alternatively, the worm gear may be an input gear and the worm may be an output gear.

In the described embodiment, the rack is provided on the follower, i.e. on a race that rotates with the wing tip device. Alternatively, the toothed rack may be arranged on the guide, i.e. on a race which is rotationally fixed relative to the stationary vane. In this case the transmission of the electric motor 30 and gear assembly 31 between the electric motor 30 and the rack 43 would be mounted in the wing tip device 4. Rotation of the electric motor 30 will cause the transmission of the worm drive 32, the electric motor 30 and the gear assembly 31 between the electric motor 30 and the rack 43 to rotate about the rack 43 (which is rotationally fixed to the fixed wing 3), thereby rotating the wing tip device 4 about the axis of rotation B between the flight configuration and the ground configuration. This arrangement may be used in any of the above embodiments.

In the described embodiment, the wing tip device is a planar tip extension. In other embodiments, the wing tip device may comprise or consist of a non-planar device such as a winglet.

In the illustrated embodiment, the prime mover 30 is an actuator in the form of an electric motor 30. It should be understood that any suitable actuator may be used, including, for example, a hydraulic or pneumatic actuator.

The aircraft may be any type of aircraft, including any aircraft, such as a manned aircraft or an Unmanned Aerial Vehicle (UAV). However, the aircraft is preferably a passenger aircraft.

Where in the foregoing description reference has been made to integers or elements having 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. The reader will also appreciate 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, while potentially beneficial in certain embodiments of the invention, may not be desirable in other embodiments and therefore may not be present. Where "or" is used in the foregoing description, it means "and/or".