Abstract:
A rotor blade of a wind power plant in which the rotor blade has a longitudinal extension that extends from a rotor blade root substantially to a rotor blade tip. At least in one region of the rotor blade, an aerodynamic cross-sectional profile is provided, which has a leading edge (nose) and a trailing edge, which are connected via a suction side and a pressure side of the cross-sectional profile. The rotor blade is subdivided at least in a longitudinally extended section into a front rotor blade section with the leading edge and a rear rotor blade section with the trailing edge. The rear region of the front rotor blade section and the adjacent front region of the rear rotor blade section are connected through an I-beam.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a rotor blade of a wind power plant, wherein the rotor blade has a longitudinal extension, which extends from a rotor blade root substantially to a rotor blade tip, wherein, at least in one region of the rotor blade, an aerodynamic cross-sectional profile is provided, which has a leading edge (nose) and a trailing edge, which are connected via a suction side and a pressure side of the cross-sectional profile. 
     Furthermore, the invention relates to a method for fabricating a corresponding rotor blade. Moreover, the invention relates to a method for producing a belt pair of a rotor blade and a fabrication mold for the production of a belt pair for use in a rotor blade. 
     2. Description of Related Art 
     Rotor blades for wind power plants are normally built in two shells, namely one shell on the suction side of the rotor blade and one shell on the pressure side of the rotor blade, and adhered together. Two webs or spars, which are adhered to the belt for the suction side and to the belt for the pressure side and ensure buckling safety in the blade, are usually located between the shells. The belts provide in particular for the torsional or bending stiffness of the rotor blade and represent, in combination with the webs or respectively spars, the support structure of the rotor blade. 
     In particular in the case of large rotor blades, the production of the rotor blades is time-consuming and expensive. For this reason, such large rotor blades are produced in several parts as just two shells and then adhered. The individual parts hereby become smaller, whereby the production time and the costs from potential production errors are reduced. For example, refer to DE 31 13 079 A1 and EP 1 965 074 A2. 
     Also, reference is made to WO 03/093672 A1, which discloses a rotor blade for wind power plants with a shell, the airfoil cross-section of which is reinforced against bending in the flapwise direction through belts provided pairwise and opposite the airfoil chord of the rotor blade and through webs between them, wherein the belts consist of plastic fiber reinforced in the longitudinal direction and have a glass fiber and a carbon fiber reinforced section in the longitudinal direction. 
     BRIEF SUMMARY OF THE INVENTION 
     The object of the present invention is to provide for a rotor blade that is to be produced simply and precisely as well as cost-effectively, a corresponding method for fabricating said rotor blade as well as an efficient method for producing a belt pair and a corresponding fabrication mold for the production of a belt pair for use in a corresponding rotor blade. 
     The object is achieved through a rotor blade of a wind power plant, wherein the rotor blade has a longitudinal extension, which extends from a rotor blade root substantially to a rotor blade tip, wherein, at least in one region of the rotor blade, an aerodynamic cross-sectional profile is provided, which has a leading edge (nose) and a trailing edge, which are connected via a suction side and a pressure side of the cross-sectional profile, which is further formed in that the rotor blade is subdivided at least in a longitudinally extended section into a front rotor blade section with the leading edge and a rear rotor blade section with the trailing edge, wherein the rear region of the front rotor blade section and the adjacent front region of the rear rotor blade section are connected by an I-beam. 
     By providing an I-beam, which can also be called a double-T beam within the framework of the invention, a very efficient and cost-effective production of a corresponding rotor blade is possible. The rotor blade can hereby be prefabricated in two halves and the connection, in particular adhering of adjacent webs, which extend from a suction side to a pressure side and which are in particular connected with respective belts to an I-beam, contribute to a high stability. It was hereby surprisingly determined that one component, which contributes to the stabilization or respectively strength of the rotor blade and, as an important component, has a load-bearing function, can first be split in the fabrication of the rotor blade and, through corresponding connection of the parts of the load-bearing structure, in particular adhering, a still sufficient stability or respectively preferably even increased stability is generated. 
     The longitudinal extension, which extends from the rotor blade root substantially to a rotor blade tip, means in particular that the longitudinal extension does not have to be present exactly up to the rotor blade tip; it can also be offset at an angle so that the longitudinal extension from the rotor blade root lies at an angle to a longitudinal extension, which would go to the rotor blade tip. The angle can hereby lie, for example, between −5° and 5°. The angle can also be so large that, in the case of a rotor blade fabrication, in which a prefabricated rotor blade tip with an extension in the longitudinal direction of up to 5 m is attached to the rest of the partial span, for example the longitudinal extension to the trailing edge or leading edge can lie on the seam at the joining edge of the partial span to the rotor blade tip. It is particularly preferred if in the longitudinal extension from the rotor blade root to the rotor blade tip a shift towards the leading edge or trailing edge of the rotor blade of 200 mm to 300 mm from the rotor blade tip is provided so that a corresponding angle of the longitudinal extension to an imaginary longitudinal extension from the rotor blade root to the rotor blade tip results. 
     The I-beam preferably has a web, which extends from the pressure side to the suction side within the rotor blade, and also a belt on the pressure side as well as a belt on the suction side. The belt is hereby preferably inserted within the rotor blade and is connected with an outer lying shell. 
     The web preferably comprises web feet, which form with the web the shape of a square bracket or the shape of a Z. 
     A particularly simple and efficient fabrication is given when the I-beam is divided in the longitudinal extension. The I beam parts are preferably connected with each other, in particular adhered. The I-beam preferably has I-beam parts, which comprise a web, wherein the I-beam is divided in longitudinal extension and two-dimensionally, in particular in a plane, which is defined by the web. The web is hereby a substantially two-dimensional component, wherein the plane of the division passes right through the web, substantially parallel to the lateral surfaces of the web. Through the adhesion, which can in particular also be realized using glass fibers, and is realized for example with a plastics technique using at least one resin and at least one fiber layer, in particular glass fibers and/or carbon fibers and/or aramid fibers, an adhesion, for example with a transfer molding technique, an infusion technique or a vacuum-supported infusion technique, can occur. 
     If two belts each close the I-beam preferably towards the suction side and towards the pressure side, which have a distance from each other, which is smaller than the extension of the belts in the direction from the leading edge to the trailing edge of the rotor blade, a particularly stable construction of the rotor blade is possible. 
     The spaced belts are preferably connected on the suction side and/or on the pressure side through adhesion, each with one web foot of the web. The web foot then has a corresponding extension in the chord direction between the leading edge and the trailing edge or respectively an almost tangential extension to the airfoil in the area of the web, which enables a sufficient rigid or respectively stable connection of the belts both on the pressure side as well as on the suction side. 
     The rotor blade is preferably divided in particular during the production additionally at the leading edge and/or the trailing edge. This results in an even more simple and exact fabrication option for the rotor blade. For a corresponding fabrication method and a corresponding fabrication mold, which enables this, we refer in full to the patent application of the patent applicant from Aug. 12, 2008 with the title “Verfahren and Fertigungsform zur Fertigung eines Rotorblatts für eine Windenergieanlage”, with file reference DE 10 2008 038 620.0. 
     Another solution of the object is a rotor blade of a wind power plant, wherein the rotor blade has a longitudinal extension, which extends from a rotor blade root substantially to a rotor blade tip, wherein, at least in one region of the rotor blade, an aerodynamic cross-sectional profile is provided, which has a leading edge (nose) and a trailing edge, which are connected via a suction side and a pressure side of the cross-sectional profile, which is further formed in that a belt divided in the longitudinal extension of the rotor blade is provided, the belt parts of which have a distance from each other, which is smaller than the extension of a belt part in the direction from the leading edge to the trailing edge. The distance of the belts in the chord direction of the airfoil is thus smaller than the width of a belt part. 
     The divided belt hereby has substantially the contour of the rotor blade in the area, in which the belt is arranged in the rotor blade, i.e. the divided belt is accordingly curved and twisted in the longitudinally axial direction, wherein the twist represents, in particular, a type of wringing around the longitudinal axis or respectively around the longitudinal extension and the curvature is, in particular, a type of bending of the rotor blade toward the longitudinal axis. The divided belt is thus correspondingly preferably “flexed” and “twisted.” 
     The division of the belt should be understood in particular such that a corresponding distance is provided from the rotor blade leading edge to the rotor blade trailing edge. Alternatively, the divided belt can also be understood as two belts arranged next to each other, the distance of which is comparatively small. The divided belt can thus also be two belts arranged next to each other, which are designed in particular such that they withstand the load of a normally used single belt. Using a divided belt or respectively two belts arranged next to each other, the fabrication accuracy of rotor blades, which consist in the longitudinal extension of two parts or respectively rotor blade sections or respectively comprise them, is particularly high. 
     The distance is preferably less than ½, in particular preferably less than ¼ of the extension of a belt part or respectively of a belt in the direction from the leading edge to the trailing edge of the rotor blade. The divided belt is preferably substantially provided over the entire longitudinal extension of the rotor blade. 
     A web, which extends from the suction side to the pressure side of the rotor blade, is preferably connected, in particular adhered, with the belt parts so that the web forms an I-beam with the belt parts. A particularly stable rotor blade is hereby possible. 
     The object is further achieved through a method for fabricating a rotor blade of a wind power plant, wherein the fabricated rotor blade in its longitudinal extension, which extends from a rotor blade root substantially to a rotor blade tip, has at least one region, in which the rotor blade has an aerodynamic cross-sectional profile, which has a leading edge (nose) and a trailing edge, which are connected via a suction side and a pressure side of the cross-sectional profile, with the following method steps:
         Providing at least two rotor blade sections fabricated and divided in the longitudinal direction of the rotor blade, wherein the division is arranged between the leading edge and the trailing edge,   Applying or inserting of a first web part extending substantially from the pressure side to the suction side into a first divided rotor blade section and a second web part extending substantially from the pressure side to the suction side into a second divided rotor blade section and   Connecting, in particular adhesion of, the first web part with the second web part so that a double web forms.       

     The stability of the web is already increased through the establishment of a double web. The application or insertion of a first web part extending substantially from the pressure side to the suction side into a first divided rotor blade section and a second web part extending substantially from the pressure side to the suction side into a second divided rotor blade section includes the application or insertion of these respective web parts into the inside of the rotor blade sections so that they are attached to the inner wall of the rotor blade sections or respectively of a belt arranged there. The understanding of application or insertion also includes attachment. 
     The application or insertion of the first and the second web part preferably comprises a connection, in particular adhesion, of the first and second web part, each to one belt on the pressure side and one belt on the suction side per rotor blade section. 
     Through the connection, in particular adhesion, of the first, in particular square-bracket-shaped, web part with the second, in particular square-bracket-shaped, web part, an I-beam preferably forms, comprising at least four belts and a double web. It is hereby particularly simple to connect the two rotor blade sections with each other so that a very stable structure results. 
     According to the invention, a method for fabricating a rotor blade of a wind power plant is provided, wherein the fabricated rotor blade in its longitudinal extension, which extends from a rotor blade root substantially to a rotor blade tip, has at least one region, in which the rotor blade has an aerodynamic cross-sectional profile, which has a leading edge (nose) and a trailing edge, which are connected via a suction side and a pressure side of the cross-sectional profile, wherein the following method steps are provided:
         Providing at least two rotor blade sections fabricated and divided in the longitudinal direction of the rotor blade, wherein the division is arranged between the leading edge and the trailing edge,   Applying or inserting a web extending substantially from the pressure side to the suction side, which has at least two web feet, into a first divided rotor blade section so that a part of the web feet protrudes out of the rotor blade section:   Connecting, in particular adhesion of, the protruding parts of the web feet with a second divided rotor blade section.       

     An I-beam, comprising four belts and the web, preferably forms through the connection, in particular adhesion, of the web with the rotor blade sections. The terms application or insertion can also include an attachment. 
     During the production of the rotor blade, preferably a rotor blade tip area and/or a rotor blade root can be provided as prefabricated insert, each of which do not necessarily have to be divided in the longitudinal extension. The longitudinal extension of these prefabricated insert parts can extend from a few centimeters up to 5 m. 
     Preferably, one suction side section and one pressure side section are connected, in particular adhered, with each other at least for one rotor blade section for the provision of two rotor blade sections fabricated and divided in the longitudinal extension of the rotor blade. 
     The two rotor blade sections preferably form a nose box and/or an end box of a rotor blade. 
     Preferably, one belt is respectively connected, in particular adhered, to a suction side and a pressure side of each rotor blade section for the provision of two rotor blade sections fabricated and divided in the longitudinal extension of the rotor blade. 
     The method according to the invention and the further developments of the method according to the invention are preferably carried out in a joining device, which is designed to hold the rotor blade sections or respectively suction side sections and pressure side sections as well as webs and the like with corresponding holding devices. Alternatively, these components can also still be at least partially arranged or respectively held in a fabrication mold. A corresponding fabrication mold is disclosed in the aforementioned German patent application DE 10 2008 038 620.0. 
     The object is further achieved through a method for producing a belt pair of a rotor blade of a wind power plant, in particular for the production of a rotor blade according to the invention, wherein the belt pair is produced in a fabrication mold, which has the contour of the rotor blade in the area of the belt pair and extends at least over the length of a section of the rotor blade, in particular in the longitudinal extension. 
     It is hereby possible to produce very precisely a belt pair for use in a rotor blade, which is arranged in the one hand on the suction side and/or on the pressure side of the rotor blade and serves in particular to connect shell segments or respectively rotor blade sections or suction side and pressure side sections with the belt pair so that a very exact fabrication of a rotor blade fabricated with it is possible. In particular, a very high joint accuracy or respectively connection accuracy can be established by adhering to a preferably constant distance between the belt pair over the length of the section, in particular of the aerodynamic region, of the rotor blade and preferably from the blade root up to the blade tip or substantially from the blade root substantially up to the blade tip. 
     The section preferably extends from a region near the rotor blade root up to the rotor blade tip or up to a section end of the rotor blade near the rotor blade tip. In particular, in the last variant with the extension up to a section end of the rotor blade near the rotor blade tip, a fabrication of the rotor blade is hereby provided, in which a prefabricated rotor blade tip is attached to a longitudinally extending, divided rotor blade section. For this, the belt pair is then adjusted according to the section length of the divided rotor blade sections, namely in the longitudinal extension of the divided rotor blade sections. The prefabricated rotor blade tip section or respectively the prefabricated rotor blade tip can hereby have a length of a few centimeters up to several meters, in particular of up to 5 m. 
     An intermediate web, in particular middle web, is preferably provided in the fabrication mold, which is designed either as a single piece with the fabrication mold as intermediate web, in particular middle web, or as a removable intermediate web, in particular middle web. A constant distance can hereby be achieved very exactly between the belt pairs. Within the framework of the invention, the term “belt pair” also means two belts, which are produced next to each other in a fabrication mold, or also the term “in the longitudinal direction or respectively longitudinal extension of the rotor blade of the divided belt.” 
     The object is finally achieved through a fabrication mold for the production of a belt pair of a rotor blade of a wind power plant, in particular for use in a rotor blade according to the invention such that the fabrication mold has the contour of the rotor blade in the area of the belt pair on the suction side or the pressure side of the rotor blade and extends at least over the length of a section, in particular of the aerodynamic region, of the rotor blade. 
     The fabrication mold preferably has an intermediate web, in particular middle web, which is designed either as a single piece with the fabrication mold or as a removable intermediate web, in particular middle web. A recess is preferably provided for the removable intermediate web, in particular middle web. This simplifies the production of the belt pair. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is described below based on embodiments without restricting the general idea of the invention; explicit reference is made to the figures with regard to all particulars according to the invention not explained in more detail in the text. The drawings show in: 
         FIG. 1  a schematic representation of a rotor blade of a wind power plant according to the invention, 
         FIG. 2  a schematic representation of corresponding components of a rotor blade in corresponding joining devices in a first step in the fabrication of the rotor blade, 
         FIG. 3  a schematic representation of a state of the fabrication of a rotor blade that is more advanced compared to  FIG. 2 , 
         FIG. 4  a schematic representation of a state of the rotor blade fabrication that is more advanced compared to  FIG. 3 , 
         FIG. 5  a schematic representation of a state of the rotor blade fabrication that is more advanced compared to  FIG. 4 , 
         FIG. 6  a sectional representation of a fabrication mold according to the invention for the production of a belt pair, 
         FIG. 7  a schematic sectional representation of a further production mold according to the invention for the production of a belt pair, 
         FIG. 8  a schematic representation of a rotor blade of a wind power plant according to the invention, 
         FIG. 9  a schematic representation of the fabrication of a rotor blade in an advanced state, 
         FIG. 10  a schematic sectional representation of a part of a fabricated rotor blade according to the invention, 
         FIG. 11  a schematic sectional representation of a part of a fabricated rotor blade according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following figures, the same or similar types of elements or respectively corresponding parts are provided with the same reference numbers so that a corresponding re-introduction can be omitted. 
       FIG. 1  schematically shows a rotor blade  10  according to the invention, which has a longitudinal extension  11  from a rotor blade root  12  to a rotor blade tip  13 . A cross-sectional profile  15 , which is aerodynamically active and has a suction side  18  and a pressure side  19 , is represented in rotor blade  10 . The aerodynamic cross-sectional profile  15  also has a leading edge  16  (nose) and a trailing edge  17 . 
     Furthermore, a belt pair consisting of the belts  28  and  29  is represented schematically, which have a distance  50  from each other and are arranged, for example, on the suction side  18 . The belts  28  and  29  are provided in section  20 , i.e. in this exemplary embodiment of  FIG. 1  from the blade root  12  to the rotor blade tip  13 . A corresponding belt pair consisting of the belts  30  and  31  on the pressure side  19  of the rotor blade  10  is not shown. The aerodynamic region  14  of the rotor blade  10  is also sketched, which substantially ensures the lift. The section  20  can also be accordingly shorter, for example end with a specifiable first distance from the rotor blade tip  13  and/or with a specifiable second distance from the rotor blade root  12 . The rotor blade  10  can be divided during production in the area of the longitudinal extension  11  shown in  FIG. 1 . Furthermore, it can also be divided at the leading edge  16  and the trailing edge  17 . 
       FIG. 2  shows an apparatus for fabricating a rotor blade  10 , wherein two joining devices  36  and  37  are provided, onto which shell segments  32 ,  33 ,  34 ,  35  of a rotor blade  10  are held. The shell segment  32  corresponds with a rotor blade shell on the pressure side  19  associated with a leading box or respectively a nose box  21  and the shell segment  34  belongs to the suction side  18  of the leading box or respectively of the nose box  21 . Corresponding belts  28  and  30  are connected, in particular adhered, with the shell segments  32  and  34 . The adhesion can be realized, for example, with a resin. The shell segments  32  and  34  are fixed by means of a few suction elements  44  using suction air in the joining device  36 . The shell segments  33  and  35  are accordingly fixed through suction elements  44  through suction air in the joining device  37 . 
     The shell segment  33  can belong to the suction side of an end box  23  and the shell segment  35  to the pressure side of an end box  22 . The shell segments  32  through  35  can be made for example of a glass fiber reinforced fabric with a resin, e.g. epoxy resin. The rotor blade parts are preferably fabricated using a plastics technique. In the plastics technique, a resin and at least one fiber layer, in particular made of glass fibers and/or carbon fibers and/or aramid, such as kevlar fibers in particular, are preferably used. A resin transfer molding (RTM) technique or a resin infusion molding (RIM) technique, in particular a vacuum-assisted resin (VAR) infusion technique and/or a laminating technique, for example with so-called prepregs, can be used for fabrication of the rotor blade shell segments  32 - 35 . The fabrication of the rotor blade shell segments  32 - 35  is already finished in  FIG. 2  so that the fabricated shell segments can be applied onto or respectively inserted into the joining devices  36  and  37 . 
     The belts  28 - 31  applied on the shell segments or respectively connected or respectively adhered with them can already be connected with the shell segments in the fabrication in a fabrication mold. 
     The joining devices  36  and  37  each have pivot axes  45  and  46  in order to be able to pivot the pivot parts  38 - 41 . 
       FIG. 3  represents an advanced stage of fabrication of the rotor blade according to the invention. A web part  26  is fixed via suction elements  44  on a positioning device  63  attached precisely to the second pivot part  39  or respectively aligned with it. The web part  26  has a web foot  65  towards the suction side  18  and a web foot  67  towards the pressure side  19 . The web foot  65  is adhered precisely with the belt  30  by means of an adhesion  60 , for example made of a resin. Accordingly, a positioning device  62  is connected or aligned with the third pivot part  40 . A web part  27  is fixed on the positioning device  62  via suction elements  44 . The web part  27  has web feet  64  and  66 . The web foot  65  is connected with the belt  31  via an adhesion  61 . A precise alignment of the web part  27  with the belt  31  and the shell segment  33  is also possible here. 
     Subsequently, as shown in  FIG. 4 , the first pivot part  38  is pivoted around the pivot axis  45  so that an adhesion  68  of the web foot  67  with the belt  28  can take place. This can also be done in a precise manner. Furthermore, an adhesion  77  of the shell segment  32  with the shell segment  34  is realized via an adhesion part  78  connected with the shell segment  34  in the nose area of the nose box  21 . 
     In order to produce an end box  22 , the fourth pivot part  41  is pivoted around the pivot axis  46  and the web foot  66  is adhered with a glue  69  with the belt  29  so that a precise adhesion takes place between the web  27  and the belt  29  or respectively the shell segment  35 . The trailing edge of the rotor blade is also connected correspondingly via an adhesion  76 . 
     The joining devices  36  and  37  preferably have, in addition to the pivot axes  45  and  46 , a linear motion device (not shown), with which the molded parts  38  and  39  or respectively  40  and  41 , that is the corresponding pivot parts  38  through  41 , can be closed in a straight-line movement. 
     As shown by arrow  85 , the joining device  37  provided with the wheels  42  and  43  is subsequently moved in the direction of the joining device  36 , namely after a hardening of the adhesions  60 ,  68 ,  77 ,  61 ,  69  and  76  and after a removal of the positioning devices  62  and  63 . 
     As represented schematically in  FIG. 5 , a glue gap results between the web parts  26  and  27 . Therein, a flow medium, for example a glass fiber entanglement  70 , is provided. This can be one or more layers of continuous mat, glass fabric, glass cloth or a spun material compressible in the thickness direction. The glue gap is preferably sealed vacuum-tight all around. Seals  72  and  73  are provided for this, which can be realized as vacuum film or as a solid sealing surface. Corresponding rubber seals, which do not have reference numbers, are also indicated. 
     A resin sprue  74  is indicated on the bottom end of the glue gap and a vacuum connection  75  on the top end. When establishing negative pressure or respectively vacuum, a gluing medium in the form of, for example resin  71 , is suctioned into the glue gap through the sprue so that the gap is completely filled. The leading and trailing web or respectively the web parts  26  and  27  hereby result in a web, which can also be called the middle web, which is located in the middle of the belts  28 ,  29  and  30 ,  31 . It can be seen that the belts  28  and  29  have a distance from each other and the belts  30  and  31  have a corresponding distance from each other. The gluing medium can be an infusion resin or a low-viscosity adhesive resin. The arrangement of sprue  74  or respectively resin sprue  74  and vacuum connection  75  can also be interchanged. 
     Over the longitudinal extension of the rotor blade  10 , more sprues may be necessary under certain circumstances. Accordingly, several vacuum connections can also be provided. In particular when the blade length is relatively long, for example around 60 m. 
     The arrangement of the rotor blade  10  or respectively the rotor blade shell segments  32 - 35  with the suction side elements facing downward is not absolutely necessary. It can also be positioned the other way round. 
     After the resin sprue, for an aerodynamically sensible connection and for closing the gap between the belt parts or respectively the belt pairs  28 ,  29  and  30 ,  31 , this gap can be closed flush with a resin and, if applicable, also with a glass fiber entanglement or the like. 
     The web parts  26  and  27  can be made for example of biaxial fabric, i.e. of glass fiber or carbon fiber or respectively aramid fiber fabric or comprise them. The fabrics have orientations of ±20° to ±50° and lie in particular in a range of ±30° to ±45°. Towards the inside, i.e. towards the glass fiber entanglement  70 , a layer of fabric, in particular biaxial fabric, can be provided and, for example, four layers of biaxial fabric in the area of the rotor blade root  12  can be provided on the outer surface and a layer of biaxial fabric in the area of the rotor blade tip  13 . The distance of the web parts  26  and  27  preferably lies in a range between 1 mm and 20 mm, in particular preferably between 2 mm and 3 mm. 
     In order to achieve a sufficient buckling resistance of the produced rotor blade  10 , the blade can also have a trailing edge web outside the area of the I beam  25 , which results from the adhesion of the web parts  26 ,  27  with the belts  28 ,  29  and  30 ,  31 . The trailing edge web is preferably arranged in the end box  22  and can be arranged there on the suction side and/or on the pressure side and reaches, for example, in the case of a 61 m blade from approx. 8 m to 52 m calculated from the rotor blade root  12 . 
     The joining device  36 ,  37  is preferably used since the occupancy time of the rotor blade production mold is thus reduced. The four shell segments  32  through  35  are correspondingly aligned in the pivot parts  38  through  41 . The adhesion of the web parts  26  and  27  takes place in particular two-dimensionally. The particularly exact positioning and alignment of the shell segments  32  through  35  and the web parts  26  and  27  preferably takes place through the positioning device indicated in  FIGS. 1 through 5 , which are represented as suction elements  44  and are preferably adjustable in height or respectively distance to the pivot parts. The very large mold accuracy is thereby achieved in that the belts or respectively belt parts  28 ,  29  and  30 ,  31  are each produced together, that is the belts  28  and  29  together and the belts  30  and  31  together in one fabrication mold. For this, schematic sectional representations of corresponding fabrication molds, in which the corresponding belts  28  and  29 , which serve as examples here, are fabricated, are shown in  FIGS. 6 and 7 . 
     In the fabrication molds  54  and  55 , two cavities for the belts  28  and  29  to be produced, which are divided in the middle, are correspondingly provided. In the exemplary embodiment according to  FIG. 6 , the division takes place through a middle web  56  insertable in a recess  58  and in the exemplary embodiment according to  FIG. 7  through a middle web  57  fabricated as one piece with the fabrication mold  55 . 
     Dry glass fibers are laid into the mold and immersed through a resin sprue  74  in the cavities with a resin  71 . Through the fixed mold division or respectively the production of the two belts  28  and  29  in one single mold, the two belts  28  and  29  always fit together perfectly. Both belts have an identical curvature and twist, which corresponds with the rotor blade  10  to be fabricated in the area of the respective belts. The fabrication of the belts  28  and  29  occurs in the exemplary embodiments according to  FIGS. 6 and 7  preferably with a vacuum-supported infusion technique, for which resin sprue connections  83  and  84  and vacuum connections  81  and  82  are provided. A vacuum film  80  is provided for sealing, which is connected left and right in the  FIGS. 6 and 7  with sealing strips, which have no reference number and, for example, can be designed as rubber lips, with the fabrication molds  54  or respectively  55 . After fabrication, the belt  28  has an extension  52  and the belt  29  an extension  52 ′ according to the embodiment according to  FIG. 6  and in  FIG. 7  the belt  28  has an extension  53  and the belt  29  an extension  53 ′. Accordingly, the distance  50  in the case of the use of a middle web  56  according to  FIG. 6  is smaller than in the case of a middle web  51  according to  FIG. 7 , since the middle web  51  in  FIG. 7  is sloped or respectively beveled. 
     In the case of the embodiment according to  FIG. 6 , both belts  28 ,  29  are demolded from the fabrication mold  54  together and the parting strip is subsequently removed. Smaller alignment errors of the parting strip can hereby occur, which are however insignificant, since the two belt halves are always designed complementarily, i.e. substantially uniformly. The embodiment according to  FIG. 7  enables lower tolerances of the belts  28 ,  29  or respectively a lower tolerance or respectively differences in the distance  51  in the longitudinal extension of the rotor blade, but leads to greater distances  51  and thus to greater glue gaps between the web parts  25  and  26  in  FIG. 5 . The distance of the web parts  25  and  26  can then lie in the range of 10 mm or more. 
     The joint fabrication of two belts in one fabrication mold saves production space and time during fabrication. Moreover, belts produced in this manner, which are then used in the longitudinal extension of the rotor blade on a pressure side or a suction side, also instead of a web, which connects the belts and which is adhered in the middle, i.e. a double web, for example in a connection by means of a box spar according to patent application DE 10 2008 038 620.0, can be used. 
     A controllable, process-secure and accessible web-to-shell adhesion is possible through the invention. High forces can be transferred through a large-area middle web adhesion or respectively web adhesion, through which an I-beam forms. It is also not necessary to use an external pressing force to displace the glue, since the web parts  26  and  27  are pressed onto each other through the supplied vacuum. The web parts are resilent to tension, but are relatively soft in themselves. Local differences in the thickness of the glue gap, that is the gap between the web parts  26  and  27 , which result from tolerances in the adhesive surfaces or respectively of the web surfaces, are leveled out to the thickness of the flow medium through the vacuum. The flow medium also ensures the resin flow through the pressed-together surfaces. This is not visible on the fabricated blade. 
       FIG. 8  shows a schematically represented rotor blade  10  according to the invention. In the case of this rotor blade, a longitudinal division of the rotor blade  10  into rotor blade sections  21  and  22  is provided, wherein the division takes place along a longitudinal extension  11  or respectively  11 ′ or  11 ″. The longitudinal extension  11  goes from the rotor blade root to the rotor blade tip  13 . The longitudinal extension  11 ′ runs from the rotor blade root substantially to the rotor blade tip  13  and ends in the area of the rotor blade tip  13  at a distance h 2  from this tip. Accordingly, in the case of a distribution in the longitudinal extension  11 ″, it can go up to an edge in the area of the rotor blade tip  13 , which shows a connection edge  95  between a prefabricated rotor blade tip and the rest of the rotor blade or respectively rotor blade section  20 . In this case for example, the rotor blade tip does not have to be divided in the longitudinal extension. 
     The distance to the connection edge  95  is specified with h 1 . It can be up to 5 m. However, a distance of a few centimeters can also be provided. As mentioned above, the rotor blade tip section  94  can be prefabricated separately. Accordingly, angle α and β to longitudinal extension  11 ′ or respectively longitudinal extension  11 ″ can be provided between the longitudinal extension  11  between the rotor blade root  12  and the rotor blade tip  13 . α can lie, for example, in the range from 0.1 to 2° and β in the range from 2° to 5°. 
       FIG. 9  shows a schematic sectional representation through the fabrication device, in which corresponding rotor blade sections are already inserted, wherein in this case in the trailing rotor blade section  22 , i.e. in the end box, a web  90  is glued in, which has web feet  92  and  93 , each of which overlap to the left and right and are adhered to the belts  29  and  31  with corresponding adhesions  69  and  61 . The protruding parts of the web feet  92  and  93  are then adhered to the belts  28  and  30  after the removal of the positioning device  62  and the pushing together of the rotor blade sections in the direction of the arrow  85 . 
       FIG. 10  and  FIG. 11  show further schematic cross-sectional representations of connection options of rotor blade sections, which are not shown here. The belts  29  through  31 , which are adhered with corresponding adhesions  110  to the respective web feet  97  and  98  of the web  96 , are represented. The web  96  has the shape of a square bracket or respectively of a square C. The web feet  97  and  98  protrude beyond the distance of the belts  28  and  29  or respectively  30  and  31 . 
     Accordingly,  FIG. 11  shows a connection, in which a web  99  is provided that is Z-shaped. Accordingly, the web feet  100  and  101  are adhered to the belts  28  and  29  or respectively  30  and  31  through adhesions  110 . 
     All named characteristics, including those taken from the drawings alone, and individual characteristics, which are disclosed in combination with other characteristics, are considered alone and in combination as important to the invention. Embodiments according to the invention can be fulfilled through individual characteristics or a combination of several characteristics. 
     REFERENCE NUMBER LIST 
     
         
         
           
               10  Rotor blade 
               11 ,  11 ′,  11 ″ Longitudinal extension 
               12  Rotor blade root 
               13  Rotor blade tip 
               14  Aerodynamic area 
               15  Cross-sectional profile 
               16  Leading edge 
               17  Trailing edge 
               18  Suction side 
               19  Pressure side 
               20  Section 
               21  Nose box 
               22  End box 
               23  Trailing area 
               24  Leading area 
               25  I-beam 
               26  Web part 
               27  Web part 
               28  Belt 
               29  Belt 
               30  Belt 
               31  Belt 
               32  Shell segment 
               33  Shell segment 
               34  Shell segment 
               35  Shell segment 
               36  Joining device 
               37  Joining device 
               38  First pivot part 
               39  Second pivot part 
               40  Third pivot part 
               41  Fourth pivot part 
               42  Wheel 
               43  Wheel 
               44  Suction element 
               45  Pivot axis 
               46  Pivot axis 
               47  Double web 
               50  Distance 
               51  Distance 
               52 ,  52 ′ Extension 
               53 ,  53 ′ Extension 
               54  Fabrication mold 
               55  Fabrication mold 
               56  Middle web 
               57  Middle web 
               58  Recess 
               60  Adhesion 
               61  Adhesion 
               62  Positioning device 
               63  Positioning device 
               64 - 67  Web foot 
               68  Adhesion 
               69  Adhesion 
               70  Glass fiber entanglement 
               71  Resin 
               72  Seal 
               73  Seal 
               74  Resin sprue 
               75  Vacuum connection 
               76  Adhesion 
               77  Adhesion 
               78  Adhesion part 
               80  Vacuum film 
               81  Vacuum connection 
               82  Vacuum connection 
               83  Resin sprue connection 
               84  Resin sprue connection 
               85  Arrow 
               90  Web 
               91  Web 
               92  Web foot 
               93  Web foot 
               94  Rotor blade tip section 
               95  Connection edge 
               96  Web 
               97  Web foot 
               98  Web foot 
               99  Web 
               100  Web foot 
               101  Web foot 
               110  Adhesion 
             h 1  Distance 
             h 2  Distance 
             α Angle 
             β Angle