Patent Application
20190367157
This application claims the benefit of the German patent application No. 102018113144.5 filed on Jun. 1, 2018, the entire disclosures of which are incorporated herein by way of reference.
The invention relates to a system for driving a flap arrangement between a retracted position and an extended position, a wing having such a system as well as an aircraft.
In commercial aircraft, often so-called high lift systems are provided on a wing allowing to increase a lift generating area of the wing as well as its camber. Predominantly, these high lift systems comprise a trailing edge flap arrangement and a leading edge flap arrangement. For example, a leading edge flap arrangement comprises a flap that is extended from a recess at an underside of the wing into a position upstream of the wing. For this so-called Kruger flap, numerous different actuation mechanisms exist.
Depending on a storing position of a Kruger flap in its retracted position and the actuation mechanism to extend the Kruger flap into the desired deployed position, an additional cut-out or recess is required in the fixed leading edge to allow an actuation mechanism to reach a maximum deployed position. This cut-out needs to be sealed in order to maintain a smooth outer surface for cruise flight conditions. Typically, these cut-outs are closed by elastomeric seals.
In an alternative solution, the gap is at least partially sealed through a gap covering flap, which is moved between an open and a closed position through the action of a main flap.
DE 10 2008 056 655 A1 shows a gap covering device and an adjusting mechanism for a gap covering device, which is actuated through an arrangement that includes a prestressed lever moved by a flap.
A device that closes a cut-out in a leading edge of a wing for an actuation mechanism coupled with a leading edge Kruger flap that neither requires an elastomer seal nor a complicated mechanism for deploying a covering flap may be helpful.
Therefore, it is an object of the invention to propose a system for driving a flap arrangement that allows the extension of and retraction of a flap and to seal cut-outs required for an actuation mechanism for the flap, while the covering flap actuation mechanism shall be as simple as possible.
A flap system for driving a flap arrangement between a retracted position and an extended position is proposed. The system comprises a main flap, a covering flap, a main link, an auxiliary link, a first connecting link, and a second connecting link, wherein the main link comprises a first main link joint for rotatably supporting the main link on a first structurally fixed point, and a second main link joint rigidly coupled with the main flap, wherein the first connecting link comprises a first connecting link joint for rotatably supporting the first connecting link on a second structurally fixed point, which is located rearward of the first structurally fixed point, and further comprises a second connecting link joint, wherein the second connecting link comprises a third connecting link joint for rotatably supporting the second connecting link on a third structurally fixed point, which is located rearward of the first structurally fixed point and at a distance to the second structurally fixed point, and further comprises a fourth connecting link joint, wherein the auxiliary link comprises a first auxiliary link joint coupled with the main link at a distance to the first main link joint, and further comprises a second auxiliary link joint, wherein the covering flap is rotatably coupled with one of the auxiliary link and the first connecting link, and wherein the other one of the auxiliary link and the first connecting link is rotatably connected to either the first connecting link or the auxiliary link, and wherein the connecting links, the auxiliary link and the main link are arranged to actively place the covering flap forward of the main flap in a retracted position of the main flap and rearward of the main flap in at least one extended position of the main flap.
The main flap may be a flow body having an elongate shape as well as a leading edge and a trailing edge. It may be curved in a similar way to a Kruger flap or another type of flow influencing control surface of an aircraft. In a preferred embodiment, the main flap is a leading edge flap configured to be moved relative to a leading edge of a wing.
The main link is rigidly attached to the main flap and is adapted to move the main flap between a retracted position and one or more extended positions through rotation of the main link about the first main link joint. When placing the main flap at a leading edge region of a wing, it is configured to snugly fit into a recess on an underside of the wing to close the recess completely and provide a continuous surface. However, by using the main link to move the main flap between usually very distinctly distanced positions, the wing additionally has a cut-out for allowing the main link to move between the retracted position and a fully extended position. The covering flap is provided for closing this additional cut-out by being placed on said cut-out. The covering flap is directly adjacent to the main flap, i.e., directly forward of it, when the main flap is in its retracted position. Hence, the covering flap is a part of the aerodynamic surface in the retracted position of the main flap. The main link may be bent or straight.
According to the invention, the covering flap is exclusively moved through a kinematic arrangement comprising the auxiliary link, the first and second connecting links and their attachments to the main link, the second and third structurally fixed point and the covering flap. This means, that the covering flap is exclusively driven by the main link and does not require a dedicated drive.
The covering flap is connected to the second connecting link and one of the first connecting link and the auxiliary link. Hence, the covering flap is coupled with two independent links in form of a four-link chain. It is moved by the other one of the first connecting link and the auxiliary link that is not directly connected to the covering flap. Consequently, in a first alternative, the first connecting link may hold one point of the covering flap in a fixed distance to the second structurally fixed point and is moved by the auxiliary link that is coupled to the main link. In the other alternative, the auxiliary link holds the respective point of the covering flap in a fixed distance to the first auxiliary link joint and may be moved by the first connecting link that is coupled to the second structurally fixed point, when the main link is moved. As the second structurally fixed point is located rearward of the first structurally fixed point, the motion of the covering flap relative to the main flap not only depends on the coupling to the first connecting link or the auxiliary link, but also on the arrangement of both flaps in the retracted position of the main flap. Preferably, the covering flap is located forward of the main flap in the retracted position of the main flap. Hence, the main link and the connecting link cross each other when the main flap is in the retracted position.
As indicated, the auxiliary link is moved through the induced motion of the first auxiliary link joint. Thereby, a motion of the second auxiliary link joint is influenced. Depending on the setup of the first connecting link and the auxiliary link the covering flap is thereby moved, too.
If the main link is moved into an extended position in a first rotation orientation, the auxiliary link moves at least in a certain motion stage in an opposite rotation direction if the auxiliary link is coupled with the covering flap and if the first connecting link is to the auxiliary link. Hence, by moving the main flap into a forward direction, the covering flap is moved rearwardly and releases the additional cut-out for allowing the motion of the main link into a forward direction into the cut-out. Additionally, since the covering flap is also coupled with the second connecting link, it changes its orientation during this motion.
In this regard, the “forward” direction is to be understood as a first direction, which may be considered a flight direction when the flap system is attached to an aircraft. Consequently, the rearward direction is to be considered the opposite direction.
Further, the term “rigidly” is to be understood as firmly holding the main flap or the covering flap, while a rotation or a translational motion of the respective cover relative to the respective link is not permitted.
Additionally, the flap arrangement is to be understood as the main flap and the covering flap.
By using a covering flap to actively close the additional cut-out for accommodating the motion of the main link, additional elastomer seals are not required. The covering flap may be designed such that it snugly fits into the additional cut-out. Further, the cut-out may comprise resting surfaces that at least partially surround the additional cut-out to allow the covering flap to conduct a circumferential contact of the resting surfaces when covering the additional cut-out.
It may also be preferred to arrange the resting surfaces and corresponding contacting surfaces of the covering flap in such manner that the covering flap experiences a certain pre-tension force between the resting surfaces and a rim section of the covering flap. The pre-tension force supports an exact alignment of the covering flap relative to the cut-out.
In an advantageous embodiment, the main link has an L-shape. The L shape may comprise a first leg and a second leg that are connected to each other substantially under a right angle. The first leg and the second leg may comprise different lengths. For example, the first leg may include the first main link joint. The first leg may comprise a greater length than the second leg. With such a setup, the first structurally fixed point may be placed in an upper, forward location of the flap system, wherein the main link extends into a rearward direction. At a rearwardmost position the second leg may extend into a lower direction. Resultantly, the main link may carry the main flap in an upside-down position at a lowermost space of the flap system. An L-shaped main link is commonly found in many leading edge high lift systems of an aircraft. However, such a shape of a main link is not mandatory and any shape is suitable, as long as the main link is able to hold the main flap and to provide a swiveling motion of the main flap.
In an advantageous embodiment, the main link has a first main link section that extends from the first main link joint in the direction of the second main link joint up to a transition region, wherein the main link has a second main link section that extends from the transition region in the direction of the second main link joint and wherein the second main link section has a larger width in a direction parallel to a swivel axis of the first main link joint than the first main link section. Hence, the route along which the second main link joint extends along the main flap clearly exceeds the route of the first main link joint along a direction parallel to said swivel axis. The cut-out to be covered by the covering flap for accommodating the main link motion, however, is dimensioned to conform the first main link section. It is therefore advantageous to dimension the first main link section to be as narrow as suitable.
Advantageously, the main link may comprise a recess extending vertically to a swivel axis of the first main link joint and the recess is designed for moving at least the auxiliary link, the first connecting link and the covering flap through the recess when moving the main flap. As stated above, the auxiliary link and the main link may cross each other due to the distanced positions of the first structurally fixed point and the second structurally fixed point and the opposite positions of the main flap and the covering flap in the retracted state. Hence, the auxiliary link and the first connecting link either have to pass the motion of the main link in a side by side relationship or, as proposed, they pass the main link through the recess. By this, a symmetric introduction of loads between the main link, the first connecting link and the auxiliary link is achieved.
In this regard, it is mentioned that the auxiliary link may exemplarily be connected to the main link from within the recess. Hence, the first connecting link joint may be coupled with a surface that faces in a direction parallel to a swivel axis defined by the first connecting link joint. Advantageously, two opposite attachment points to couple the first connecting link with the main link may be used.
In an advantageous embodiment, the recess extends into the second main link section. Since the second main link section advantageously has a larger width than the first main link section, the covering flap may simply pass through the recess in a region in the second main link section. As the covering flap is configured for covering the additional cut-out for accommodating the first main link section, it is of a clearly smaller width than the second main link section.
As indicated above, the covering flap has a width that exceeds the width of at least a part of the main link in a direction parallel to a swivel axis of the first main link joint. The covering flap has a width that at least slightly exceeds the width of the main link in a region around the first main link joint. Also, the covering flap has a width that is less than the width of at least a part of the main link in a direction parallel to a swivel axis of the first main link joint. In the example of the second main link section having a larger width than the first main link section the covering flap has a width that is between both widths of the main link sections.
Preferably, the second auxiliary link joint is swivably connected to the covering flap. The position of a part of the covering flap is therefore clearly defined by the motion of the auxiliary link.
In an advantageous embodiment, the auxiliary link comprises a third auxiliary link joint, which is arranged between the first auxiliary link joint and the second auxiliary link joint, wherein the second connecting link joint is rotatably connected to the third auxiliary link joint. Hence, the third auxiliary link joint is coupled with the second structurally fixed point, such that the motion of the auxiliary link is limited. At the same time, the second auxiliary link joint is preferably rotatably connected to the covering flap. The point of the covering flap, which is connected to the auxiliary link is therefore urged to move through the auxiliary link, if the main link is moved. Together with a rigid structure defined by the covering flap as well as the second connecting link the mechanism realized by the system according to the invention is a six-link-chain.
In a preferred embodiment, the third auxiliary link joint is arranged less than 25% away from a center of the auxiliary link. Hence, the third auxiliary link joint is arranged roughly in the center of the auxiliary link. The auxiliary link may therefore provide a distinct swiveling motion induced by the connection to the main link through the first connecting link.
Still further, a connecting line between the first auxiliary link joint and the second auxiliary link joint is substantially parallel to the second connecting link in the retracted position of the main flap. In this regard, said connecting line and the second connecting link may be aligned in such a way that they enclose an angle of 10° at a maximum in the retracted position.
The first connecting link may further extend into the direction of the first main link joint when the main flap is in the retracted position.
The invention further relates to a wing for an aircraft, the wing comprising a leading edge region and a trailing edge region, the wing further comprising at least one system according to the above description.
It is clear that when introducing the system to the wing, a main flap is preferably supported through at least two main links, which leads to the integration of at least two auxiliary links and two connecting links for carrying two covering flaps.
Further, it is clear that a wing may be equipped with a plurality of flap systems.
Preferably, the system according to the invention is arranged in the leading edge region of the wing.
It is further preferred that the wing comprises a cut-out for receiving at least a part of the main link, wherein the covering flap is designed to cover the cut-out in the retracted position of the main flap. The covering flap constitutes a part of the aerodynamic surface of the wing when the main flap is in the retracted position. Also, the cut-out is preferably arranged at an underside of the leading edge region.
The invention further relates to an aircraft having at least one such wing.
Other characteristics, advantages and potential applications of the present invention result from the following description of the exemplary embodiments illustrated in the figures. In this respect, all described and/or graphically illustrated characteristics also form the object of the invention individually and in arbitrary combination regardless of their composition in the individual claims or their references to other claims. Furthermore, identical or similar objects are identified by the same reference symbols in the figures.
In
The main link 12 exemplarily comprises an L-shape. Here, a first main link section 32 that extends up to the first main link joint 28 represents a first leg of the L-shape. A second main link section 34, which is substantially arranged at a right angle to the first main link section 32 and extends up to the second main link joint 30, represents a second leg of the L-shape. Between both main link sections 32 and 34 a transition region 36 is present, which connects both main link sections 32 and 34 in a tangentially continuous manner.
The covering flap 10 has a crescent-shaped profile and is thinner than the main flap 8. In the retracted position, the covering flap 10 is placed forward of the main flap 8 and directly connects to the trailing edge 22 of the main flap 8. As demonstrated in further figures, the covering flap 10 is configured for covering a cut-out 38 for accommodating the main link 12 during an extension motion. This is further demonstrated in
The covering flap 10 is rotatably connected to the auxiliary link 18 through a second auxiliary link joint 40. A first auxiliary link joint 42 is rotatably connected to the main link 12.
The auxiliary link 18 comprises a third auxiliary link joint 44, to which the first connecting link 14 is attached. Additionally, the first connecting link 14 comprises a first connecting link joint 46, which is attached to a second structurally fixed position 48. Said second structurally fixed position 48 is rearward of the first structurally fixed position 26.
Furthermore, the second connecting link 16 comprises a third connecting link joint 50, which is rotatably connected to a third structurally fixed point 52. A fourth connecting link joint 54 is rotatably coupled with the covering flap 10. Hence, the motion of the covering flap 10 is determined by the combined motions of the auxiliary link 18 and the second connecting link 16. By moving the main link 12 about the first structurally fixed point 28, holding the first connecting link 14 at the second structurally fixed point 48, and holding the second connecting link 16 at the third structurally fixed point 52, the auxiliary link 18 rotates about the first auxiliary link joint 42 and the second connecting link 16 swivels around the third structurally fixed position 52. In the retracted position, i.e., an initial position, the first connecting link 14, the auxiliary link 18 as well as the main link 12 pairwisely cross each other. Additionally, a connection line between the first auxiliary link joint 42 and the second auxiliary link joint 40 is substantially parallel to the second connecting link 16.
In
Due to the first connecting link 14 being held at the second structurally fixed point 48 by the first connecting link joint 46, the auxiliary link 18 is urged into an anti-clockwise rotation. The second auxiliary link joint 40 therefore moves in a rearward direction. The main link 12, however, rotates in a clockwise direction during the extension of the main flap 8. Due to being coupled with the covering flap 10, which is urged into an anti-clockwise direction by the auxiliary link 18, the second connecting link 16 also conducts a swiveling movement around the third structurally fixed point 52 and thereby determines the orientation of the covering flap 10. In this situation, the fourth connecting link joint 54 is moved rearwardly.
During this motion, the covering flap 10 is moved rearwardly and passes the main link 12. The orientation of the covering flap 10 is determined by the auxiliary link 18 and the second connecting link 16. While in the retracted position the covering flap 10 slightly points upwardly in a forward oriented direction, it slightly points downward in the motion state shown in
In
In
It may also be preferred to arrange the resting surfaces and corresponding contacting surfaces of the covering flap 10 in such manner that the covering flap 10 experiences a certain pre-tension force between the resting surfaces and a rim section of the covering flap 10. The pre-tension force supports an exact alignment of the covering flap 10 relative to the cut-out 38.
A recess 60 is apparent in the main link 12, which extends through the main link 12 vertically to the swivel axis 58. Due to the different widths of the main link section 32 and 34, the recess 60 is designed to have a T-shape. A wider part of the T-shape is arranged in the second main link section 34, while the narrower part of the T-shape is arranged in the first main link section 32. Since the cut-out 38 for accommodating the main link 12 only needs to receive the first main link section 32, the covering flap 10 only needs to cover a width slightly larger than the width w1 of the first main link section 32. This allows the covering flap 10 to pass through the recess 60. The auxiliary link 18, however, is able to pass through the part of the recess 60 arranged in the first main link section 32.
Due to the symmetric design of the main link 12, the auxiliary link 18 and the covering flap 10, it is advantageous to use two first connecting links 14 instead of just one connecting link 14. They may be arranged parallel to each other to symmetrically enclose the auxiliary link 18. The arrangement of two first connecting links 14 and one auxiliary link 18 is able to pass through the recess 60 as well. Still further, the second connecting link 16 may be a single connecting link 16, which is able to pass through the two first connecting links 14. Altogether, the forces are transferred symmetrically. However, also a single connecting link 14 and two auxiliary links 16 may be used instead. In this case, the two auxiliary links 16 enclose the connecting link 14.
The first auxiliary link joint 42 may be placed inside the recess 60 and furthermore allows a very space-efficient design. For this purpose, the first main link section 32 may comprise two inner surfaces 62 that face each other. Here, two devices for coupling two first auxiliary link joints 42 are arranged. The devices may be threaded bore holes or other suitable devices.
Lastly,
While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102018113144.5 | Jun 2018 | DE | national |
