Abstract:
An adjusting device for adjusting a flap at an wing of an aircraft includes at least one flap drive for operating the flap and a plurality of drive stations comprising drive struts structured and arranged to movably connect the flap to the wing. The plurality of drive stations includes at least two first drive stations that guide the flap in a defined position in a wing chord direction. The plurality of drive stations includes at least one second drive station at which the flap is moveable in the wing chord direction. The at least one second drive station includes at least one compensation element structured and arranged to compensate constraining forces occurring in the plurality of drive stations due to relative movements between the flap and the wing in the wing chord direction.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a U.S. National Stage of International Patent Application No. PCT/IB2007/052566 filed Jul. 2, 2007, and claims priority of German Patent Application No. 10 2006 030 315.6 filed Jun. 30, 2006. Moreover, the disclosure of International Patent Application No. PCT/IB2007/052566 is expressly incorporated by reference herein in its entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an adjusting device for adjusting a high-lift flap at the airfoil wing of an aircraft, and to an airfoil wing comprising such an adjusting device. 
     2. Discussion of Background Information 
     In known high-lift systems of modern airliners and transport planes, and in particular in those having a high take-off weight, high-lift flaps provided at the wing trailing edge are movably connected to the airfoil wing by several driving stations. For operating the flap, drive links are used which comprise tension/compression elements (drive struts) connected for example via a torsion shaft to a flap drive which is typically disposed centrally. The tension/compression elements are coupled with lever arms provided at the torsion shaft and are linked with the flap in the area of the drive stations by load leading mountings. A disadvantage of this solution is that constraining forces may occur due to relative movements between flap and wing in high-lift flaps which are connected to the airfoil wing by more than two drive stations. 
     It is known from general prior art to attach the tension/compression elements to a main girder which acts on the flap by pendulum supports. In this regard, it is a disadvantage that there may occur an undesired force coupling between the normal force acting on the flap and the drive force depending on the relative displacement of the main girder due to the pendulum supports. In addition, such high-lift systems have a high weight and involve high manufacturing and mounting costs due to the required components (main girder, pendulum supports, bearings, etc.) and the complexity of the system. 
     SUMMARY OF THE INVENTION 
     In accordance with aspects of the invention, there is an improved adjusting device for adjusting a high-lift flap and an airfoil wing provided with such an adjusting device, wherein constraining forces are avoided or minimized, with minimum time and effort concerning the production. 
     In embodiments, there is an adjusting device for adjusting a high-lift flap at the airfoil wing of an aircraft, comprising at least one flap drive for operating the flap and several drive stations comprising tension and compression forces transmitting devices for movably connecting the high-lift flap to the airfoil wing. The high-lift flap is connected to the airfoil wing via at least three drive stations, including at least two first drive stations at which the flap is guided in a defined position with regard to the wing chord direction. At least one second drive station comprises at least one compensation element at which the flap is movable with regard to the wing chord direction for compensation of relative movements between the flap and the wing for compensation of constraining forces occurring in the drive stations due to relative movements in the direction of the wing chord between the flap and the wing. In additional embodiments, there is an airfoil wing of an aircraft comprising at least one adjusting device as described herein. 
     The adjusting device for adjusting a high-lift flap at the airfoil wing of an aircraft according to aspects of the invention comprises at least one flap drive for operating the flap and several drive stations, which movably connect the high-lift flap to the airfoil wing for guiding the flap by tension/compression elements. The flap drive is connected to several drive stations for adjusting the high-lift flap. According to aspects of the invention, at least one compensation element for compensation of constraining forces which are due to relative movements in the wing chord direction between flap and wing and which occur in the drive links comprising the tension/compression elements is assigned to at least one drive station. Due to the at least one compensation element in the drive links comprising the tension/compression elements, constraining forces are avoided in the flap and in the drive train, such that in comparison with general prior art systems, no additional components (main girder, pendulum supports, bearings, etc.) are required for compensation of the changes of length. Accordingly, the flap normal force is decoupled from the drive force. The adjusting device according to the invention as well as an airfoil wing provided with such an adjusting device has a light weight and can be manufactured easily and in a cost-effective manner. 
     In embodiments, the compensation element is preferably disposed in the drive link comprising the tension/compression element between a torsion shaft connected to the flap drive and the flap. 
     According to an embodiment of the invention, the compensation element is provided at least in sections to be elastic. A consistent load of the tension/compression elements is achieved by a suitable choice of the stiffness of the elastic compensation element. 
     According to an embodiment of the invention, first and second drive stations are provided. The high-lift flap is held in a defined position with respect to the wing chord direction at the first drive stations and is movable with respect to the wing chord direction for compensation of relative movements between flap and wing at the second drive stations. The compensation element inserted in the drive link comprising the tension/compression element is provided in the second drive station. 
     According to an embodiment, the high-lift flap is movably adjustably connected to the airfoil wing by three drive stations, including two first drive stations at which the flap is held in a defined position with regard to the wing chord direction and a second drive station at which the flap is movable for compensation of relative movements between flap and wing with regard to the wing chord direction. The compensation element inserted in the drive link comprising the tension/compression element is provided in the second drive station. 
     The compensation element may be provided at the tension/compression element or it may be formed by the same. 
     The compensation element may be provided between the tension/compression element and the flap. 
     The compensation element may be provided between the tension/compression element and at least one lever arm assigned to the drive link. 
     The compensation element may be provided at the lever arm element or may be formed by the same. The lever arm element may be formed to be elastic. 
     The compensation element may be provided between the torsion shaft and the lever arm element. 
     The compensation element may be linearly elastic. 
     The compensation element may be torsion elastic. 
     The compensation element may be formed by at least one spring. 
     The compensation element may comprise at least one elastomer element. 
     According to an embodiment, at least one limit stop is provided at the compensation element, limiting the admissible relative movement. Thereby, a functioning in cases of failure is assured. 
     According to an embodiment of the invention, the compensation element has a stiffness which is highly progressive in the compression direction. 
     According to an embodiment of the invention, at least one damping element may be provided for damping vibrations of the compensation element. The damping element may be formed passively or actively in this regard. The damping effect may be achieved, for example, by a spring element having a corresponding spring characteristic. 
     According to an embodiment of the invention, at least one sensor element may be provided for detecting relative movements, in particular inadmissibly large relative movements in the drive link comprising the tension/compression element. 
     The sensor element may be connected in parallel to the elastic element. 
     The adjusting device may be provided at the leading edge of an airfoil wing. 
     According to a preferred embodiment of the invention, the high-lift flap is provided at the trailing edge of the airfoil wing of an aircraft. 
     An airfoil wing of an aircraft according to the invention is provided with at least one adjusting device of that type for adjusting a high-lift flap. 
     In accordance with aspects of the invention, there is an adjusting device for adjusting a flap at a wing of an aircraft including at least one flap drive for operating the flap, and a plurality of drive stations comprising drive struts structured and arranged to movably connect the flap to the wing. The plurality of drive stations includes at least two first drive stations that guide the flap in a defined position in a wing chord direction. The plurality of drive stations includes at least one second drive station at which the flap is moveable in the wing chord direction. The at least one second drive station includes at least one compensation element structured and arranged to compensate constraining forces occurring in the plurality of drive stations due to relative movements between the flap and the wing in the wing chord direction. 
     The at least one compensation element may be arranged in the drive strut of the at least one second drive station between the flap and a torsion shaft connected to the flap drive. The at least one compensation element may be elastic at least in sections. 
     In embodiments, the flap is a high-lift flap and the at least two first drive stations hold the flap in a defined position in the wing chord direction via dropped-hinged kinematics. In further embodiments, the flap is a high-lift flap, the wing is an airfoil wing, and the flap is connected to the wing by a track-rear link arrangement. 
     The at least one compensation element may be provided at or formed by the drive strut of the at least one second drive station. The at least one compensation element may be provided between the flap and the drive strut of the at least one second drive station. 
     In embodiments, the at least one compensation element is provided between the drive strut of the at least one second drive station and a lever arm operatively connected to the drive strut, and the lever arm and the drive strut are included in a drive link. 
     In accordance with aspects of the invention, a drive link includes the drive strut of the at least one second drive station and a lever arm operatively connected to the drive strut. The at least one compensation element may be provided at or formed by the lever arm. The at least one compensation element may be provided between the lever arm and a torsion shaft of the flap drive. 
     The at least one compensation element may be linearly elastic. The at least one compensation element may be torsion elastic. The at least one compensation element may include at least one spring. The at least one compensation element may include at least one elastomer element. 
     In embodiments, the adjusting device further includes at least one limit stop provided at the at least one compensation element, wherein the at least one limit stop limits admissible relative movement. The at least one compensation element may include a stiffness that is progressive in a direction of compression. The adjusting device may further include a damping element structured and arranged to dampen vibrations of the at least one compensation element. 
     The adjusting device may further include at least one sensor element provided in a drive link including the drive strut of the at least one second drive, wherein the at least one sensor element detects relative movements. The at least one sensor element may detect inadmissibly large relative movements. The at least one sensor element may be arranged in parallel with the at least one compensation element. 
     In accordance with additional aspects of the invention, there is a method of adjusting a flap at a wing of an aircraft. The method includes driving and guiding movement of the flap relative to the wing in a wing chord direction using a plurality of drive stations. The method also includes compensating constraining forces occurring in the plurality of drive stations due to relative movements between the flap and the wing in the wing chord direction using at least one compensation element included in at least one of the drive stations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the invention are explained in detail on the basis of schematic drawings, wherein, 
         FIG. 1  shows a perspective general view of an aircraft with an adjusting device at the wing trailing edge driven by a central flap drive via a torsion shafting; 
         FIG. 2  shows a schematized cross-sectional view of adjusting device according to an embodiment of the invention; 
         FIG. 3  shows a schematized cross-sectional view of an adjusting device according to a further embodiment of the invention; and 
         FIG. 4  shows a plan view of a flap of adjusting device according to embodiments of the invention for the purpose of explaining forces and relative movements occurring at the flap. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a perspective view of a modern airliner or transport plane, which is provided with high-lift systems at its airfoil wing at the wing leading edge as well as at the wing trailing edge for increasing lift during takeoff and landing. Several high-lift flaps  2  are provided on each side at the trailing edge of the airfoil wing  1 , which are coupled by a central flap drive  20  via a torsion shafting  30  comprising a number of torsion shafts. The flaps  2  are movably adjustably connected to the airfoil wing  1  at respective drive stations  3 ,  4 ,  5  which are schematically shown in  FIG. 4 , and are held in wing span direction as well as in wing chord direction. 
       FIG. 2  shows a schematized view showing a cross-sectional view through an adjusting device according to a first embodiment of the invention. A high-lift flap (landing flap)  102  is disposed at the rear edge of the airfoil wing  1  of an aircraft, which in the embodiment shown can be operated via so-called dropped-hinge kinematics. In such dropped-hinge kinematics or swivel flap arrangement, the high-lift flap  102  is swivelled at a flap lever  116  about a swivel point  111  provided under the wing. When being extended, the flap is swivelled about the swivel point  111  disposed under the wing on a track having the form of a circular arc. A joint  122  is provided at the flap lever  116 , at which a tension/compression element  107  acts, which serves for operating the flap  102  in the sense of an extending or retracting movement on the above-mentioned circular track about the swivel point  111 , such that a drive station is provided. Preferably, at least a second drive station is provided (which is not shown), such that the high-lift flap  102  is disposed at the wing to be swivelled by two drive stations. The tension/compression element  107  is coupled with the torsion shafting  30  shown in  FIG. 1 . A compensation element formed as an elastic element  110  is inserted in the drive link comprising the tension/compression element  107  between the torsion shafting  30  and the flap  102 , which serves for compensation of relative movements in the wing chord direction between flap  102  and wing  1  and constraining forces caused thereby. In the embodiment shown in  FIG. 2 , the compensation element  110  is provided between the tension/compression element  107  and the joint  122  at the flap lever  116 , or it forms part of the tension/compression element  107  and is formed by a spring or an elastomer element. 
       FIG. 3  shows a schematized view showing a cross-sectional view of an adjusting device according to a second embodiment of the invention. At the rear edge of an airfoil wing  1  of an aircraft a high-lift flap (landing flap)  2  is disposed, which in the embodiment shown can be operated via a so-called track-rear-link arrangement. At the lower surface of the wing  1  a track  18  is provided, extending diagonally backwards and downwards, on which a carriage  19  is displaceably disposed substantially in an aircraft longitudinal direction and in a wing chord direction, respectively. The carriage  19  is coupled with the flap  2  via a first joint  11 . Between a second joint  12  located further at the back at the flap  2  and a third joint  13  disposed at the rear end of the track  18  a lever (rear link)  17  is disposed, by which the rear part of the flap  2  is pulled downwards with an increasing extension movement, thereby positioning the flap  2 . At a torsion shaft  6  comprised in the drive train (torsion shafting  30 ), a lever arm  8  or a lever arm element is provided, with which a load leading mounting  9  is coupled at or near the front end of the flap  2  via a tension/compression element (drive strut)  7 . The load leading mounting  9  is non-detachably connected to the flap  2 . A compensation element formed as an elastic element  10  is inserted in the drive link comprising the tension/compression element  7  between the torsion shaft  6  and the flap  2 , which serves for compensation of relative movements in wing chord direction between the flap  2  and the wing  1  and constraining forces caused thereby. 
     In the embodiment shown in  FIG. 3 , the compensation element  10  is provided between the tension/compression element  7  and the load leading mounting  9  or forms part of the tension/compression element  7  and is formed by a spring or an elastomer element. In this embodiment, the high-lift flap  2  is preferably disposed at the wing to be swivelled by at least three drive stations. 
     The type of flap kinematics is not essential for the present invention; other types of flap kinematics than the kinematics shown in  FIG. 2  or  3  might be used as well. 
     Relative movements between the flap  2 ;  102  and the drive link comprising the tension/compression element  7 ;  107  and constraining forces caused thereby due to reciprocal movements between the flap  2 ;  102  and the airfoil wing  1 , for example by bending, torsion or vibration of wing  1 , are compensated by the compensation element  10 ;  110 . In particular, a coupling effect is avoided between the flap normal force Fz and the tension/compression element  7 ;  107  and the torsion shafting  30 , respectively. The forces transmitted via the tension/compression element  7 ;  107  now are coupled with the relative displacement “dy” between flap  2 ;  102  and wing  1  via the spring stiffness of the compensation element  10 ;  110 . By a suitable choice of the spring stiffness and possibly also non-linear stiffness developments, a consistent load of the tension/compression elements  7 ;  107  can be achieved. 
       FIG. 4  shows a plan view of the flap  2 ;  102 , of  FIG. 2  and  FIG. 3 , respectively. The flap  2 ;  102  is held at first drive stations  3 ,  5  in a defined position with regard to the wing chord direction, and released for compensation of relative movements between flap  2 ;  102  and wing  1  with regard to wing span direction. The flap  2 ;  102  is held in a defined position with regard to the wing span direction at a second drive station  4  and released for compensation of said relative movements between flap  2 ;  102  and wing  1  with regard to the wing chord direction. The compensation element  10  or  110  is provided in this second drive station  4 , which is inserted in the drive link comprising the tension/compression element  7 ;  107  for compensation of the relative movements in the wing chord direction. This is shown in  FIG. 4  in a schematized manner. The forces acting at the first drive stations  3 ,  5  (slave stations) and the second drive station  4  (master station) in the direction of the wing chord are designated by Fy # 3 , Fy # 4 , and Fy # 5 . 
     The compensation element  10 ;  110  is preferably provided with a limit stop limiting the relative movement, such that it is limited when a determined relative movement is exceeded. In addition, the compensation element  10 ;  110  may comprise a progressive stiffness in the compression area. Thereby, the functioning in cases of failure can be assured as well. 
     In addition, a damping element for damping vibrations of the compensation element  10 ;  110  may be provided, which may be arranged within the drive link comprising the tension/compression element  7 ;  107  parallel to the compensation element  10 ;  110  or between the flap  2 ;  102  and the wing  1 . Instead of a damping by an additional specially designed damping element, a compensation element  10 ;  110  having an intrinsic damping characteristic may also be provided. 
     In order to detect inadmissibly large relative movements in the drive link comprising the tension/compression element  7 ;  107  and/or between the flap  2 ;  102  and the wing  1 , also a sensor element may be provided, which signals cases of failure, such as the breakdown of the drive at a drive station. This sensor element may be connected in parallel to the compensation element  10 ;  110 . 
     Instead of the arrangement of the compensation element  10 ;  110  in or at the tension/compression element  7 ;  107  as shown in  FIGS. 2 and 3 , the compensation element  10 ;  110  may also be provided in the lever arm element  8  of  FIG. 3  or it may be formed by the same. Furthermore, the compensation element  10  may be assembled between the torsion shaft  6  and the lever arm  8 . The compensation element  10 ;  110  may be linear-elastic, i.e., it may respond to compression or tension, or it may be torsion elastic, depending on whether it is arranged on the side of the torsion shaft as the torsion shaft  6  of  FIG. 3 , or on the side of the tension/compression element  7 ;  107  with regard to the link connection between these two parts. 
     Advantages of the adjusting device and the airfoil wing provided with the same according to the invention are a minor complexity and weight of the system, lower costs for manufacturing and mounting, and a larger available space in the area of the drive stations. Further advantages are less force coupling between the flap and its drive and less loads in the flap drive in the case of jamming or other malfunctions. 
     REFERENCE NUMBERS 
     
         
         
           
               1  airfoil wing 
               2 ;  102  high-lift flap 
               3  drive station 
               4  drive station 
               5  drive station 
               6  torsion shaft 
               7 ;  107  tension/compression element (drive strut) 
               8  lever arm 
               9  load leading mounting 
               10 ;  110  compensation element 
               11 ;  111  first joint 
               12  second joint 
               13  third joint 
               116  flap lever 
               17  lever (rear link) 
               18  track 
               19  carriage 
               20  flap drive 
               21  joint 
               22 ;  122  joint 
               30  torsion shafting