GB2323577A

GB2323577A - Interconnection system for moveable wing surfaces

Info

Publication number: GB2323577A
Application number: GB9803077A
Authority: GB
Inventors: Michael Craig Broadbent
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-02-21
Filing date: 1998-02-16
Publication date: 1998-09-30
Also published as: GB9703683D0; JPH10324299A; GB9803077D0

Abstract

Each wing of an aircraft includes a main wing section 1, and a plurality of moveable wing surfaces such as slats 3a, 3b, 3c, that are connected to the main wing section by swing arms 6. The moveable wing surfaces are interconnected by link arms 10,12 that prevent asymmetric deployment and retraction of the surfaces. Electric or hydraulic motors 18,19 are provided to deploy and retract the slats, the motor 18 driving a crank 11, which acts on the links 10. The link arms 12 may be connected to the swing arms by universal joints (16)(fig. 2), and may incorporate a turnbuckle (13). Alternatively the link arms may include a lost motion mechanism in the form of a telescopic joint (figs. 3,4).

Description

INTERCONNECTION SYSTEM FOR MOVEABLE WING SURFACES The present invention relates to an interconnection system for moveable wing surfaces, for example for deploying and retracting flaps and slats.

Technical Field Modern commercial aircraft are generally provided with moveable wing surfaces such as slats and flaps that allow the wing shape to be optimised, with regard to aerodynamic lift and drag, for different flight conditions, such as cruise, takeoff and landing. These lift enhancing devices need to be controlled to ensure against asymmetric deployment, that is, the deployment of surfaces from one wing that is not matched by the simultaneous deployment of equivalent surfaces from the other wing.

Asymmetric deployment causes aircraft roll, which can lead to a crash.

To protect against asymmetric deployment, interconnection systems are provided that link the deployment and retraction mechanisms of the aerodynamic surfaces. These systems ensure that equivalent moveable surfaces on the two wings are always deployed and retracted together.

Another potential cause of aircraft accidents is the uncommanded deployment or retraction of moveable wing surfaces, which can occur for example in the event of a component failure. It is important therefore that no single component failure can cause the uncommanded deployment or retraction of a moveable wing surface.

A common slat deployment mechanism is the paired track system, an example of which is disclosed in US patent No 4,753,402 assigned to The Boeing Company.

This system uses a pair of curved tracks to translate and rotate the slat from a retracted position where it rests directly in front of the main wing to a forward and downwardly extended deployed position.

In most paired track systems, motors at each track position actuate the surface. It is very important that the actuators work simultaneously, as otherwise the mechanism can become jammed. A torque shaft is therefore provided, which connects the tracks together and takes over if an actuator fails. Wing bending requires that the torque shaft is split with universal joints at an intermediate station. Further multiple torque shafts are connected to the tracks of other moveable surfaces, such that all the surfaces along both wings are connected together. Gears are provided at the actuator stations to increase the rotational speed of the torque shaft and reduce the transmitted torque, allowing a reduction in the total mass of the system.

It is also important that the slats of commercial aircraft do not become detached from the wing after a component failure, particularly in the case of the inner slats, because of the likelihood of damage to the fuselage or tailplane from the detached slat. In paired track designs this requirement is achieved through the addition of further tracks.

Another type of slat deployment mechanism is the swing arm, parallelogram system, examples of which are described in US patent No. 2,246,116 and International patent application No. PCT/NZ95/00096, the content of which is incorporated by reference herein. Such systems are required to meet the same safety standards as the paired track designs described above.

Object of Invention It is an object of the present invention to provide an interconnected transmission system for swing arm slat and flap systems that mitigates at least some of the disadvantages of the current systems as described above, or that at least provides the public with a useful choice.

Disclosure of Invention According to one aspect of the present invention there is provided an interconnection system for moveable wing surfaces in an aircraft having a pair of wings, each said wing including a main wing section having a leading edge and at least one moveable wing surface, each moveable wing surface being connected to the main wing section by at least two swing arms and being deployable by swinging the swing arms such that the moveable wing surface is translated both perpendicular to the leading edge of the main wing section and parallel thereto, said interconnection system including at least two link arms, the outer ends of the link arms being connected to a matched pair of moveable wing surfaces on the two wings and the inner ends of the link arms being interconnected to ensure symmetrical deployment and retraction of the matched pair of moveable wing surfaces.

By connecting the moveable wing surfaces on the two wings, asymmetric deployment and retraction of the surfaces can be prevented, thereby reducing the danger of accidents. The link arms are also very light, thereby reducing the overall weight of the aircraft, reliable and inexpensive to manufacture.

The inner ends of the link arms may be connected to a crank located within the body of the aircraft, such that rotation of the crank causes symmetrical movement of the link arms. A drive motor may be provided for driving the crank. Both link arms may thus be driven from a single motor.

According to a further aspect of the present invention there is provided an interconnection system for moveable wing surfaces in an aircraft having a pair of wings, each said wing including a main wing section having a leading edge and a plurality of moveable wing surfaces, each moveable wing surface being connected to the main wing section by at least two swing arms and being deployable by swinging the swing arms such that the moveable wing surface is translated both perpendicular to the leading edge of the main wing section and parallel thereto, said interconnection system including at least one link arm that connects at least one of said moveable wing surfaces to an adjacent moveable wing surface on the same wing to ensure that the moveable wing surfaces connected by said link arm are deployed and retracted synchronously. The interconnection of adjacent wing surfaces also ensures that all the interconnected surfaces are deployed or retracted as desired, even in the event of failure of a drive motor.

Advantageously, at least one moveable wing surface is connected by link arms to at least two adjacent moveable wing surfaces. The provision of two link arms as well as the two swing arms ensures that the moveable wing surface cannot become detached from the wing even in the event of failure of a link arm or a swing arm.

The link arms may extend substantially parallel to the leading edges of the wings.

Sealing means may be provided for sealing the gap between adjacent moveable wing surfaces.

According to a further aspect of the present invention there is provided an interconnection system for moveable wing surfaces in an aircraft having a pair of wings, each said wing including a main wing section having a leading edge and a plurality of moveable wing surfaces, each moveable wing surface being connected to the main wing section by at least two swing arms and being deployable by swinging the swing arms such that the moveable wing surface is translated both perpendicular to the leading edge of the main wing section and parallel thereto, said interconnection system including at least two inner link arms, the outer ends of the inner link arm being connected to a matched pair of moveable wing surfaces on the two wings and the inner ends of the inner link arms being interconnected to ensure symmetrical deployment and retraction of the matched pair of moveable wing surfaces, and at least one outer link arm that connects at least one of said moveable wing surfaces to an adjacent moveable wing surface on the same wing to ensure that the moveable wing surfaces connected by said outer link arm are deployed and retracted synchronously.

The link arms may be connected to the swing arms of the moveable wing surfaces.

The link arms may be connected to the moveable wing surfaces (directly or indirectly, via the swing arms) by means of universal joints.

Advantageously, at least one of the link arms includes an adjustment mechanism for adjusting the length of the link arm, to account for build tolerance differences between the wing and the moveable surfaces.

Advantageously, at least one of the link arms includes a lost motion mechanism for accommodating changes in the length of the link arm, whereby after the lost motion has been taken up, the link arm transmits either tensile or compressive loads.

Drive motors may be connected to one or more of the swing arms for deploying and retracting the moveable wing surfaces.

According to a preferred aspect of the present invention, the interconnection system comprises an inner slat mechanism with two swing arms and two adjacent link arms, such that any single failure of a link arm or a swing arm will not cause the detachment of the slat from the wing.

According to another preferred aspect of the present invention, the interconnection system comprises link arms from the inner slats to a crank housed in the fuselage, such that rotation of the crank controls the moveable surfaces of both wings simultaneously.

According to another preferred aspect of the present invention, the interconnection system comprises a linkage mechanism for deploying wing surfaces, said linkage mechanism being characterised in that it comprises a link arm universally connected at both ends to the adjacent moveable surfaces or swing arms, and an adjustment mechanism to account for build tolerance differences between the wing and the moveable surfaces.

According to another preferred aspect of the present invention, the interconnection system comprises a linkage mechanism for the secondary deployment of wing surfaces (i.e. a backup system), said linkage mechanism being characterised in that it comprises a link arm universally connected at both ends to the adjacent moveable surfaces or swing arms, and a lost motion mechanism, whereby after the lost motion has been taken up, the link arm transmits either tensile or compressive loads.

Brief Description of the drawings Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings wherein: Figure 1 shows diagrammatically a plan view of a wing with three slats at the leading edge separated by an engine pylon, Figure 2 is an diagrammatic front elevation view of a part of the wing, as per arrow 2 of figure 1, showing the gap between two slats with some of the slat leading edges removed, and Figures 3 and 4 are diagrammatic front elevation views of a part of the wing, as per arrow 2 of figure 1, showing an alternative form of the invention.

Best Mode for Carrying out the Invention Figure 1 of the drawings shows an aircraft wing 1 having a main wing section 2 with three slats 3a,3b,3c located along its leading edge 4. The slats 3a,3b,3c are shown in a fully deployed position, the retracted positions 5a, 5b, 5c being indicated by finer lines. In use, the slats 3a,3b,3c are deployed and retracted synchronously, the slats generally being deployed when the aircraft is taking off or landing and retracted when it is cruising.

Each slat 3a, 3b, 3c is connected to the leading edge 4 of the main wing section 2 by a pair of swing arms 6, each of which is pivotally connected at one end to the main wing section 2 and at the other end to one of the slats 3a, 3b, 3c. As the swing arms 6 swing from their retracted positions in which they lie approximately parallel to the leading edge 4 to their deployed positions shown in figure 1, the slats 3a, 3b, 3c are translated forwards and downwards from the leading edge of the wing. The slats 3a, 3b, 3c are also displaced inwards (approximately parallel to the leading edge 4), which ensures that when the slats are fully deployed there is no gap between the innermost slat 3a and the root of the wing 1. The swing arm mechanism is described more fully in PCT/NZ95/00096, the content of which is incorporated by reference herein.

The inner slats 3a of the left- and right-hand wings 1 are connected to one another via two inner link arms 10, which are connected at their outer ends to the inner swing arms 6 of the slats 3a. The inner ends of the inner link arms 10 are connected to a crank 11 that is located on the centreline (CL) of the aircraft. Rotation of the crank 11 drives the two inner link arms 10 inwards or outwards, so deploying or retracting the inner slats 3a. The interconnection of the two inner slats 3a ensures that they are deployed symmetrically.

Adjacent slats 3a-3b, 3b-3c on each wing are connected to one another by outer link arms 12. As shown in more detail in Figure 2, each outer link arm 12 comprises a turnbuckle device including a link tube 13, a threaded shaft 14 and an adjusting nut 15, that controls the length of the outer link arm. The ends of the outer link arm 12 are connected to the swing arms 6 of the adjacent slats 3b,3c via a pair of universal joints 16. A flexible seal 17 may optionally be provided between the ends of the adjacent slats 3b, 3c to improve the aerodynamic performance of the wing and to prevent the ingress of rain and ice. The turnbuckle device allows the length of the link arm 12 to be adjusted to compensate for build tolerance differences between the wing and the slats. The double universal joints 16 allow for wing bending, slat deployment and individual adjustment of slat rotation without adversely loading the slat structures.

The slats 3a, 3b, 3c are deployed and retracted by means of electric or hydraulic motors 18, 19 located within the fuselage and the wings. A central motor 18 is arranged to drive the crank 11, which acts on the inner swing arms 6 of the inner slats 3a via the inner link arms 10. Wing motors 19 are arranged to drive the outer swing arms 6 of the inner and outer slats 3a, 3b, 3c. The inner swing arms 6 of the outer slats 3b, 3c are connected to the outer swing arms 6 of the adjacent inboard slats 3a, 3b via the outer link arms 12. The inner link arms 10 and the outer link arms 12 are capable of transmitting compressive and tensile forces between the slats 3a, 3b, 3c and serve to ensure that the slats on the two wings are deployed symmetrically and synchronously.

When the motors 18, 19 are actuated, each of the swing arms 6 is acted upon either directly by a motor or indirectly via a link arm 10, 12. Only one wing motor is provided per slat and the total number of motors required, including the central motor 18, is only approximately half the number normally required in an equivalent paired track design. Torque shafts and their associated gear and universal joint mechanisms are also omitted. The total weight of the deployment mechanism is therefore considerably less than that of an equivalent paired track design. The mechanism is also simpler and more reliable.

To deploy the slats, the motors 18 and 19 are activated. The central motor 18 drives the crank 11 in an anti-clockwise direction (as shown in the drawings) so that it draws the two inner link arms 10 inwards. This pulls the inner slats 3a forwards and inwards, towards to wing root. The wing motors 19 simultaneously drive the outer swing arms 6 of the outer slats 3b, 3c causing those slats to move forwards and inwards. The outer link arms 12 transmit this movement to the inner swing arms 6 of the outer slats 3b, 3c. The slats 3a, 3b, 3c on both wings are thus deployed simultaneously and symmetrically. The retraction process is simply the reverse of the deployment process and so will not be described in detail.

In the event of one of the motors 18, 19 failing, the interconnection of the slats 3a,3b,3c via the link arms 10, 12 ensures that all the slats will still be properly deployed. Similarly, if one of the link arms 10, 12 fails, the slats will still be properly deployed, as each slat is driven directly by at least one drive motor. The deployment mechanism is therefore fail safe and prevents asymmetric deployment of the slats.

Further, the interconnection of the slats to one another via the link arms 10,12 reduces the risk of a slat becoming detached from the wing in the event of the failure of one of the swing arms connecting the slat to the main wing section.

An alternative form of the invention is shown in Figures 3 and 4, in which the link arm 10 or 12 includes a lost motion mechanism. In this embodiment, the link arm 12 comprises a pair of tubes 23, 24 that are connected to one another by means of a telescopic joint 25. The outer ends of the tubes 23, 24 are connected via universal joints 16 to the adjacent swing arms 6 of the slats 3b,3c. The telescopic joint 25 allows small changes in the separation of the slats 3b, 3c to be accommodated without adversely loading the slat structures. The joint 25 includes stop mechanisms such that, after the lost motion has been taken up, tensile or compressive loads are transmitted to ensure synchronous and symmetrical deployment and retraction of the slats.

Various modification s of the slat deployment mechanism are possible: for example, the link arms 10,12 may be connected directly to the moveable wing surfaces (for example, by means of universal joints) rather than to the swing arms.

The deployment mechanism described above may also be employed for deploying other moveable wing surfaces, for example wing flaps.

Claims

1. An interconnection system for moveable wing surfaces in an aircraft having a pair of wings, each said wing including a main wing section having a leading edge and at least one moveable wing surface, each moveable wing surface being connected to the main wing section by at least two swing arms and being deployable by swinging the swing arms such that the moveable wing surface is translated both perpendicular to the leading edge of the main wing section and parallel thereto, said interconnection system including at least two link arms, the outer ends of the link arms being connected to a matched pair of moveable wing surfaces on the two wings and the inner ends of the link arms being interconnected to ensure symmetrical deployment and retraction of the matched pair of moveable wing surfaces.

2. An interconnection system according to claim 1, wherein the inner ends of the link arms are connected to a crank located within the body of the aircraft, such that rotation of the crank causes symmetrical movement of the link arms.

3. An interconnection system according to claim 1, including a drive motor for driving the crank.

4. An interconnection system for moveable wing surfaces in an aircraft having a pair of wings, each said wing including a main wing section having a leading edge and a plurality of moveable wing surfaces, each moveable wing surface being connected to the main wing section by at least two swing arms and being deployable by swinging the swing arms such that the moveable wing surface is translated both perpendicular to the leading edge of the main wing section and parallel thereto, said interconnection system including at least one link arm that connects at least one of said moveable wing surfaces to an adjacent moveable wing surface on the same wing to ensure that the moveable wing surfaces connected by said link arm are deployed and retracted synchronously.

5. An interconnection system according to claim 4, wherein at least one moveable wing surface is connected by link arms to at least two adjacent moveable wing surfaces.

6. An interconnection system according to claim 4 or claim 5, wherein said link arms extend substantially parallel to the leading edges of the wings.

7. An interconnection system according to any one of claims 4 to 6, including sealing means for sealing the gap between adjacent moveable wing surfaces.

8. An interconnection system for moveable wing surfaces in an aircraft having a pair of wings, each said wing including a main wing section having a leading edge and a plurality of moveable wing surfaces, each moveable wing surface being connected to the main wing section by at least two swing arms and being deployable by swinging the swing arms such that the moveable wing surface is translated both perpendicular to the leading edge of the main wing section and parallel thereto, said interconnection system including at least two inner link arms, the outer ends of the inner link arm being connected to a matched pair of moveable wing surfaces on the two wings and the inner ends of the inner link arms being interconnected to ensure symmetrical deployment and retraction of the matched pair of moveable wing surfaces, and at least one outer link arm that connects at least one of said moveable wing surfaces to an adjacent moveable wing surface on the same wing to ensure that the moveable wing surfaces connected by said outer link arm are deployed and retracted synchronously.

9. An interconnection system according to any one of the preceding claims, wherein the link arms are connected to the swing arms of the moveable wing surfaces.

10. An interconnection system according to any one of the preceding claims, wherein the link arms are connected to the moveable wing surfaces by means of universal joints.

11. An interconnection system according to any one of the preceding claims, wherein at least one of the link arms includes an adjustment mechanism for adjusting the length of the link arm.

12. An interconnection system according to any one of the preceding claims, wherein at least one of the link arms includes a lost motion mechanism, whereby compressive and tensile loads are transmitted by the link arm only after the lost motion has been taken up.

13. An interconnection system according to any one of the preceding claims, in which drive motors are connected to one or more of the swing arms for deploying and retracting the moveable wing surfaces.

14. An interconnection system for moveable wing surfaces, the interconnection system being substantially as described herein with reference to, and as illustrated by, Figures 1 and 2 or Figures 3 and 4 of the accompanying drawings.