Abstract:
The invention relates to a device for using flow energy, in particular wind energy, comprising elements ( 2 ) that have incident-flow surfaces ( 1 ) and that are guided so as to circulate on a track at a distance to each other, wherein a rotational axis about which the elements ( 2 ) move is arranged perpendicularly to the flow direction, and comprising an apparatus ( 5 ) for transmitting the flow energy captured using the elements ( 2 ) to a generator ( 15 ). According to the invention, the apparatus ( 5 ) and the elements ( 2 ) are connected to each other in such a way that forces acting tangentially to the track ( 3 ) are transmitted and forces acting in other directions are not transmitted or are transmitted only in an attenuated manner.

Description:
The present application is a 371 of International application PCT/DE2010/001515, filed Dec. 19, 2010, which claims priority of DE 10 2009 060 437.5, filed Dec. 22, 2009, the priority of these applications is hereby claimed and these applications are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     The invention relates to a device for utilizing flow energy, particularly wind energy, with elements provided with impinged-upon surfaces, wherein the elements circulate on a track and are guided at a distance relative to each other, wherein an axis of rotation around which the elements move is arranged transversely of the flow direction, and comprising a device for transmitting the flow energy picked up by the elements to a generator 
     Such a device is known from WO 2007/118462 A1. The elements are moved parallel relative to each other and, contrary to a conventional wind wheel, are not arranged in a plane perpendicularly of the flow direction. They are fastened on a circular support constructed as a gear wheel by means of which the picked-up flow energy is transmitted to the generator. Since especially in the case of high flow velocities and devices having large dimensions with a gear wheel diameter of &gt;50 m, strong forces and possibly strong vibrations occur, high requirements are made with respect to the mechanical stability of the devices. A guidance of the elements sufficiently precise for transmitting the energy of movement at a generator can only be achieved at great structural expense. 
     SUMMARY OF THE INVENTION 
     The invention is based on the object to facilitate a utilization of the flow energy while being of simple construction and which is less dependent on the weather conditions. 
     The object is met in that the elements and the device are connected to each other in such a way that forces acting in a direction tangentially of the track are transmitted and, forces acting in other directions are not transmitted or are only transmitted to a weakened extent. 
     Weight forces of the elements and horizontal forces caused by the flow and acting on the elements are uncoupled from the device and any vibrations are transmitted only to a small extent to the device. In comparison to known devices, this apparatus can be operated at even higher flow velocities. 
     Since only the forces to be converted into electrical energy i.e., the forces acting in the direction of rotation must be transmitted through the device to the generator, the generator does not have to be rated for loads caused by other force components. 
     The device additionally connects the elements to each other. If one of the elements is in a position in which it is not driven by the flow, it is pulled along by means of the device by the other elements. 
     In one embodiment of the invention the elements and the device are mounted separate from each other, and the device is preferably mounted parallel to the track. 
     It is useful if the connection is releasable, so that in the case of the assembly or repair of the device, the device can be uncoupled from the elements and then coupled back to the elements. Advantageously, the device is provided with a coupling element which has a seat for a preferably foldable member which forms the connection and is arranged at a bearing of the elements. In directions perpendicular of the direction of movement of the elements, the member can slide in the seat. 
     In a further development of the invention, the device for force transmission is provided on a gear wheel of a rack of a gear unit of a generator, or directly on the generator. Advantageously, for this purpose, the device is provided with teeth or is provided for receiving the teeth of a gear wheel or a rack. Moreover, the device can be provided with blocks of ferromagnetic material, preferably iron, which are arranged at a distance from each other and interact with a generator known, for example, from DE 10 2009 025 289 A1. 
     In a further development of the invention, the elements and/or the device are supported preferably on rollers which are guided on rails, or on water. 
     Advantageously, the aforementioned connection is formed between the bearing of the elements and the device. 
     For supporting the elements, a rail is provided which is arranged on a scaffold. The scaffold absorbs through the rail the forces which do not act in the direction of rotation, particularly the weight forces, and the forces acting horizontally through the wind acting against the elements. 
     In a further development of the invention, for each element a separate support is provided, preferably a carriage traveling on rails and provided with at least two wheels. 
     Advantageously, in comparison to the devices known from the prior art in which all elements are fastened together on a ring, the support can be constructed so as to be more compact. 
     In an embodiment of the invention, the carriages are elastically connected to each other. Accordingly, the transmission of vibrations between the carriages and correspondingly between the elements, can be lowered. 
     While it would be conceivable to support the elements approximately in their middle along their length, in a preferred embodiment of the invention, the elements are supported at their underside and possibly additionally at their upper site and/or approximately in their middle. As a supplement or alternative, the elements can also be supported at other locations. 
     Advantageously, the elements which may be longer than 15 m, preferably longer than 25 m, and/or the device whose circular arc may have a length &gt;100 m, preferably a length &gt;300 m, are of modular construction. The transportation of individual parts, particularly the elements to the location where the device is to be installed, is simplified because special transports for large parts are no longer necessary. Even large plants can be transported at relatively lower cost to almost any location which can be reached by vehicle. 
     Advantageously, the elements are formed of at least two element parts arranged lengthwise one above the other, wherein a connection between the element parts is provided in such a way that the element parts can be tilted toward each other for compensating structural tolerances or thermal expansions of the element parts as well as of the device as a whole by at most 2° in relation to their longitudinal axis. 
     In the following, the invention will be explained in more detail in connection with embodiments and the enclosed drawings which refer to these embodiments. Shown in isometric illustrations, 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  shows a device according to the invention, 
         FIG. 2  shows a detail of the device of  FIG. 1 , 
         FIG. 3  shows an additional detail of the device of  FIG. 1 , 
         FIG. 4  shows the detail of  FIG. 3  in a different view, 
         FIG. 5  shows another detail of the device of  FIG. 1 , 
         FIG. 6  shows another detail of the device of  FIG. 1 , 
         FIG. 7  shows another detail of the device of  FIG. 1 , 
         FIG. 8  shows a detail of another device according to the invention, 
         FIG. 9  shows a detail of a further device according to the invention, 
         FIG. 10  shows an embodiment of a part of the device according to the invention, 
         FIG. 11  shows another embodiment of the part according to  FIG. 10 , 
         FIG. 12  shows details of a part of the device according to the invention, 
         FIG. 13  shows another device according to the invention, and 
         FIG. 14  shows another device according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A device according to the invention according to  FIG. 1  includes ten elements  2  with impinged-upon surfaces  1  for picking up wind energy, which elements are arranged on circular rails  19 ,  23 ,  30  parallel offset relative to each other along a track  3  so as to be rotatable about an axis  4  shown by a broken line. The device is provided with a scaffold  39  which absorbs the forces transmitted by the elements to rails  19 ,  23 ,  30 . 
     The elements  2  which have a total length of 50 m are of modular construction and composed of four parts, each having a length of 12.5 m, and are arranged lengthwise one above the other. 
     As shown in  FIG. 2 , the elements  2  are rotatably supported in a ball head bearing  20  on a carriage  17  arranged on the rails  19 . The carriage  17  has four rollers  18 , wherein always two of the rollers travel on one of the two rails  19 . In addition, ropes  22  are fastened to the carriage  17  which are connected with a middle or upper support of the elements  2  (not shown here). 
     Rods  40  are fastened to joints  21  of the carriage  17 , wherein the rods have certain elasticity, and form a horizontal connection to adjacent carriages  17 . 
     In  FIG. 3  is shown how the elements  2  are supported at the middle thereof. For guiding the elements  2 , a rail  23  is provided which serves for horizontally supporting the elements  2  by means of rollers  24  attached to a support  10 . The support  10  is connected through a connecting member  9  to a ring  5  which is movable parallel to the rail  23  and is provided on its outer side with teeth, not illustrated here, for transmitting the rotational movement of the elements  2  caused by the wind to a generator  15 . The ring  5  is guided horizontally by rollers  28  and vertically, as can be seen especially in  FIG. 4 , by rollers  27 . 
     The ring  5  is made of an aluminum sheet on which a toothed belt is arranged. 
     The connecting element  9 , seen in more detail in  FIG. 4 , engages in a seat provided in a coupling element  11  seated on the ring  5 , wherein the coupling element  11  can slide in the radial direction but transmits any forces generated in the direction of movement of the elements. The elements  2  can be uncoupled from the ring  5  by folding the connecting element  9  out of the coupling element  11 . 
       FIG. 5  shows the upper support  29  of the elements which forms, essentially in the same manner as the support in the middle, a support in the horizontal direction with rollers  24   a  on the rail  30 . 
     As can be seen particularly from  FIG. 6 , the ring  5  is formed of a plurality of individual partial pieces which can be connected to each other at joints  31 . 
       FIG. 7  shows how the ring  5  transmits the movement produced with the elements  2  to a generator  15 . The ring  5  is pressed by means of rollers  41  against an endless belt  32  guided around two cylinders wherein, the belt is provided on its outer side with teeth, not shown here, which engage the teeth of the ring  5 . The movement of a cylinder rotated in this manner is transmitted through a shaft to a generator  15 . At the bottom side of the shaft, a coupling  51  is provided which has a position in which the torque of the shaft is transmitted to the generator  15 , and a different position in which no force is transmitted. 
     The belt  32  is connected via the other cylinder through another shaft and a coupling  52  to a motor  53  by means of which the ring  5  can be driven and, in this manner, the ring and the elements can be brought into a certain position, for example for repair operations. 
     When operating the device, the motor  53  is uncoupled and the movement of the ring is transmitted through the coupling  51  to the generator. Analogously, for moving the ring with the motor  53 , the coupling  51  is adjusted in such a way that no force is transmitted. 
     Reference will now be made to  FIGS. 8 to 13  in which equal or equivalent parts are provided with the same reference numeral as those in  FIGS. 1 to 7  and to the respective reference numeral a letter has been added. 
     In the embodiment illustrated in  FIG. 8 , for transmitting the movement energy of the elements  2   a , a ring  5   a  is configured as a chain of a chain gear unit. It is provided with several links  6  arranged at a distance from each other, wherein the links  6  interact with the gear wheels  7 . When the ring  5   a  is moved, the gear wheels  7  are rotated and drive a generator  15   a.    
     In the embodiment according to  FIG. 9 , iron blocks  8  are arranged at a distance from each other and on a ring  5   b  for transmitting the movement energy, wherein the iron blocks are guided by a generator  16  known from DE 10 2009 025 298 A1. When the iron blocks  8  are moved over coils of the generator  16 , a voltage is induced at the coil because of the permeability of the space at the coil which changes over time. 
     Reference will now be made to  FIGS. 3, 10 and 11  in which various devices for aligning the elements  2  are illustrated. The device according to  FIG. 3  includes a gear wheel  35  which engages in another gear wheel provided with an electric motor  26 . By rotating the gear wheel connected to the electric motor, the elements  2  can be rotated about its longitudinal axis. 
     In the embodiment illustrated in  FIG. 10 , the elements  2  are each connected to a plate  37  which has a lateral recess in which a support is fastened. The support is provided with a rope or a leaf spring  36 . By means of an electric motor, the possible radius of movement of the plate  37  can be adjusted and, thus, a possible pivoting radius of the elements  2  can be adjusted. Depending on the wind direction acting on the elements  2 , the elements  2  can be pivoted in positions to the left and to the right of the support  36 . 
     By means of a control device  38  illustrated in  FIG. 11 , a position of the elements  2  can be exactly controlled. A protrusion  44  engaging in a recess in a plate  37   a  is mounted so as to be slidable along a rod  35 . By displacing the protrusion  44  on the rod  45 , the plate  37   a , together with the elements  2 , are rotated. 
       FIG. 12  shows connections of parts of the elements  2  of modular construction which permit tilting of the elements relative to each other by at most 1°. In the example according to  FIG. 12 a   , two sheet metal pieces  46  provided with slots engage into each other.  FIG. 11 b    shows a rod  47  of an elastically deformable synthetic material. 
     As can be seen particularly in  FIGS. 12 c  and 12 d   , the elements  2  can also be connected to each other through pipes  48  and  49  which can be pushed into each other. They are secured against rotation and displacement in an axial direction by a protrusion  50  projecting into a recess in the outer pipe  49 . 
     During operation of the device, the elements  2  are put in motion under the influence of wind and they travel along the rails  19 ,  23  and  30  on a circular track. 
     The alignment of the elements  2  in relation to the wind direction and in dependence on their respective positions can be adjusted by means of the control devices  35 ,  36  or  38 . The alignment can be controlled by means of a computer program in dependence on the wind direction and the wind speed. 
     During their movement along the rails  19 ,  23  and  30 , the elements  2  take along the ring  5 . For this purpose, they are each connected to the ring  5  through the connecting member  9  which only transmits forces in a tangential direction relative to the ring  5  and is otherwise, particularly in the radial and vertical directions, displaceable with negligible force transmission in the coupling element  10 . Accordingly, only forces in the direction of rotation of the elements  2  are transmitted to the ring  5 . Any forces which occur during operation of the device, particularly also forces caused by vibrations which do not act in the direction of rotation, are absorbed by the rails  19 ,  23  and  30  or by the support scaffold on which the rails  29 ,  23  and  30  are fastened, are not transmitted to the ring  5  or are transmitted to the ring  5  only to a small extent. 
     The movement of the ring  5  is transmitted, in accordance with  FIG. 7 or 8  by the gear wheels to the generators  15 ,  15   a  and are there transformed into electrical energy or are conducted by means of the iron blocks  8  via the generators  16  and there, as is known from DE 10 2009 025 298 A1, electrical voltage is induced. 
     As is apparent particularly from  FIG. 13 , the elements  2  can also be stored lengthwise in the middle of carriages  17 . The carriages  17  are rotatably mounted by means of radially aligned rods  13  on a pole arranged in an axis of rotation of the pole  12  arranged in an axis of rotation of the rotary movement of the elements  2 . The transmission to a generator  15   a  takes place in accordance with the embodiment illustrated in  FIG. 8 . Alternatively, the movement of the elements  2  could be picked up by means of a generator arranged on the pole  12  to which the movement of the elements  2  is transmitted through the rods  13 . 
     In another embodiment, not illustrated, a rail  23   a , in comparison to the embodiment of  FIG. 12 , could also be offset further inwardly, particularly at a center of gravity of the elements  2  and the rods  13 . 
       FIG. 14  shows another device according to the invention in which the elements  2   c  as well as rails  19   a ,  23   a  and  30   a , and a ring  5   c  are arranged on an outer side of a scaffold  39   c . In this embodiment, the scaffold  39   c  is arranged on the side of the device facing the wind, not in front of the elements  2   c  as seen in the wind direction. Accordingly, turbulence of the wind prior to impinging on the elements  2   c  is completely eliminated. 
     It is further conceivable to arrange several of the devices one above the other as illustrated in  FIGS. 1, 13 and 14 , as described above. In this manner, a tower is formed with several groups of rotating elements, devices and appropriate supports, wherein the produced current can be picked up separately by one of them.