MXPA00000955A - Connection of a wind energy plant rotor blade to a rotor hub - Google Patents

Abstract

The invention relates to a rotor blade in a wind energy plant, comprising at least one recess arranged in the area of the base (6) of the rotor blade and extending substantially perpendicular to the longitudinal axis of said rotor blade (6) to accommodate a cross-bolt (16,18) which can be joined to a traction element (20,22) to enable connection of the rotor blade (6) to a rotor hub (11) in a wind energy plant (1). The invention further relates to a rotor for a wind energy plant, comprising a rotor hub (11) and at least one rotor blade (6) secured to said hub (11), in addition to a wind energy plant. The invention is characterized in that the recess only partially crosses through the rotor blade.

Description

CONNECTION OF THE ROTOR ALABE OF ONA PLANT OF EOLIC ENERGY IN A COBO OF ROTOR DESCRIPTION OF THE INVENTION; The present invention relates to a rotor blade for a wind or wind energy apparatus with at least one recess in the region of the base of the rotor blade, which essentially extends transversely to the longitudinal axis of the rotor blade. the taking of a transverse pin, which when connecting the rotor blade in a rotor hub of a wind energy apparatus is connected to a traction element. The invention also relates to a rotor for a wind power plant with a rotor hub and at least one rotor blade attached to the rotor hub as well as a wind power apparatus with such a rotor. A rotor blade as well as the rotor of the aforementioned type for a wind energy apparatus are known. They are presented, for example, in a wind power device under the name AELOUS II for use as a test device developed by Messersc midt -Bolkow Blohm (MBB) ("Wind power apparatus" Erich Hau 2nd edition, Springer Verlag, Berlin Heidelberg, New York, ISBN 3-540-5743-1, page 203). In the wind energy apparatus is the fixation of the blades subjected to high forces in the axis or REF. : 32023 tree of the wind energy device that is coupled with the generator, a general problem, because because of the f? Ferzas that act on the rotor, the parts are subjected to extreme stresses. The constructive design of the so-called rotor blade connection, that is, the fixing of the rotor blade to the rotor hub, is therefore of great importance. In a known wind energy apparatus the rotor blade consists of a composite material in the area of the so-called base of the rotor blade, this in the end area of the rotor blade connected to the rotor hub by means of a metal flange consisting of of an internal and external annular flange, where the base of the rotor blade grips between the internal and external annular flange and is fixed by glue and screw. For the manufacture of the screw connection a bolt is fitted through the rotor blade by a transpasante perforation of the rotor blade and is screwed. The flange is screwed with its exire opposite the base of the rotor blade with the rotor hub. This construction of the rotor blade connection is constructively relatively complicated and heavy, since the metal flange has a great weight. It is particularly disadvantageous that the rotor blade, through the perforations for receiving the bolts in the area of the base of the rotor blade, is weakened in a non-limiting manner. "foteailfci -t,. ssa &aiAasaisasassfc". negligible. Another known wind power device has a steel flange connection as the rotor blade connection, in which the base of the rotor blade is clamped between an internal and an outer flange and the two flanges are screwed together. The connection of the two flanges with the rotor hub is made through a retracted flange ring with the help of high load expansion screws. In this construction, a large part of the metal flanges, often up to one third of the total weight of the rotor blade or blade, form. Furthermore, the course of the force due to a radial application between the base of the rotor blade and the retracted flange is unfavorable, since there is an undesirable lever effect. In the above mentioned test apparatus AEILUS II applies a connection called transverse bolt, where the so-called transverse bolt in the area of the base or root of the rotor blade, (this in the end area next to the hub of the rotor blade) is arranged in transpasante perforations , which are formed in the rotor blade and pass through it completely. The transverse bolts disposed within the transverse perforations are laminated on the rotor blade or rotor blade and serve as running elements within the rotor blade. The bolts ~ &., ** ^ transverse are each connected with a traction element, which is formed as a bolt-shaped traction anchor, which is screwed with the rotor hub. By means of the tensile element subjected to traction, the rotor blade is pressed into the hub and this stops. In this construction, it is equally disadvantageous that the rotor blade in the area of the base of the rotor blade is strongly weakened by the transpassing perforations for the reception of the transverse bolts. In addition, the course of the force in the area of the rotor hub of the flange type is unfavorable. The task proposed by the invention consists in providing a rotor, a blade or rotor blade, as well as a wind energy apparatus, in which the disadvantages of the current state of the art are amply avoided and that present a connection between the blade of the rotor and the easy-to-manufacture rotor hub, which remains safe under extreme stresses. By means of the construction according to the present invention of a notch or recess crossing but not completely but only partially, the rotor blade in the area of the base thereof weakens much less, as is the case, in the current state of the art, where the rotor blade is completely crossed by a through hole to receive the transverse bolt. According to the invention, it is achieved that the rotor blade due to the small weakening, with a comparable construction size, resists greater efforts. With this a rotor blade is securely fixed in a hub of a wind power apparatus, and the size of the rotor blade connection can be kept relatively small, so that it can be constructed comparatively light. The connection of the rotor blade according to the invention supports the extreme stresses to which the rotor blade and the rotor hub are subjected in the area of the base of the rotor blade, with a long life. Especially with the application of epoxy composite material reinforced with fiber with lighter material and simultaneously robust for the rotor blades, a long-lasting movement of the transverse bolts at the base of the rotor blade can be carried out. Thus, a favorable force conduction of a bolt transverse to the epoxy resin composite material of the rotor blade is produced. A particularly preferred embodiment of the rotor blade according to the invention and the rotor is characterized in that the recess is constructed as a blind hole. In this way they can be simply constructed from the outside in the rotor blade. Another advantage occurs because the transverse bolts, which are arranged in the mounting state within the blind holes reachable from the outside, can be replaced if necessary, without damaging the rotor blade. 5 Favorably for the purpose pursued multiple blind holes are provided spaced to receive multiple transverse bolts in the rotor blade, because in this way the mechanical strength of the rotor blade connection can be increased, which is especially needed in large wind power devices. The blind holes may be spaced apart so that the material only weakens insignificantly through the blind holes. Especially preferred is a form of embodiment of the invention in which the blade of the blade of the rotor in the area of the base of the blade of the rotor has a widened cross section and the blind hole or blind holes are arranged in the area of the cross-section widened. This measure can also essentially increase the connection between the rotor blade and the rotor hub, since the rotor blade due to the widening of the cross section in the area of the base of the rotor blade will be subjected to low stresses and with this it will be usable with large forces. By the arrangement of according to the invention of the holes in the area of the In the enlarged cross-section, a favorable force conduction from the transverse bolt to the rotor blade material is made possible, while an essentially low surface pressure is present. on the surface, limit between the transverse bolts and the inner surface of the recess. According to a preferred embodiment of the invention, the cross section of the rotor blade on both sides is enlarged in the direction of an end section of the rotor blade on the side of the hub. In this way, a force conduction is made from the transverse bolts to the robust rotor blade. According to a further embodiment of this embodiment, the rotor blade has two opposite thickening sections, each formed in one piece with the rotor blade, and the blind holes are arranged at least partially in the region of a thickening section. . The composite thickening sections for broadening the cross section can be simply shaped by the adhesive laminate of several layers of fiber composite material and epoxide resin. An embodiment is furthermore particularly preferred, in which the rotor blade in the area of the base of the rotor blade has an essentially tubular end section, in which they are formed inside and out blind holes. A tubular end section can be fixed in a particularly uniform and simple manner in the rotor hub and it is especially advantageous in very large wind energy apparatuses, in which extreme forces occur, that the blades of the rotor are transformed from the tubular end section, for fixing, in a profiled wing section. Another construction is characterized by multiple perforations joined with each of the blind holes, which essentially extend in the direction of the longitudinal axis of the rotor blade to receive a corresponding traction element connectable with a transverse bolt. In this way, the tension elements are advantageously arranged partially inside the rotor blade in the perforations and can be arranged centrally in the transverse bolts, where they grip with a perforation provided with a thread, so that the transverse bolts support the force symmetrically of traction and in the main they are arranged inside the blade or rotor blade free of moments. A favorable force conduction and a high mechanical strength occurs, if the blind hole or the blind holes in the essential have a cylindrical shape and have a depth, which is approximately one third of the cross section of the blade or blade of the rotor in the area of the base of the rotor blade. A great lightness of the material together with a high mechanical resistance, are produced by an embodiment, in which the rotor blade consists essentially of an epoxide resin composite material reinforced with glass fiber. The above-explained advantages of a rotor blade according to the invention are produced in a similar manner in a rotor for a wind energy apparatus of the first-mentioned type, which is equipped with a rotor blade according to the invention. In order to avoid repetitions, therefore, as far as the advantageous effects are concerned, reference will be made to the previous embodiments. Another advantageous construction of the rotor according to the invention is characterized in that the hub of the rotor has a flange section essentially T-shaped, in its cross section, which surrounds the hub of the rotor to connect the rotor blade and the hub of the rotor by means of multiple traction elements that are connected with each transverse pin anchored in the rotor blade, is screwed with the flange section. By means of the symmetrical T-shaped flange section suitable for the intended purpose, a force conduction can be made, symmetrical from a rotor blade to the hub, when in the two free sections of the T-shaped flange section that remain essentially in a plane, the perforations are made in passing, through which pass to protrude the elements of traction or tightening. Preferably for the object pursued are the multiple traction elements in pairs parallel to each other and in the essentials in two rows arranged concentrically to each other. Thus, the opposing tightening elements in pairs can be arranged directly opposite or displaced to the traction elements of the other row. The advantages of the invention are also realized in a wind power apparatus, which is equipped with a rotor and / or a rotor blade of the type described above, in view of the advantages according to the invention achievable, we will refer to the embodiments above in dependence on a rotor blade and a rotor according to the present invention. In the following, the invention will be described in more detail by way of an exemplary embodiment of a rotor of a wind energy device with reference to the accompanying drawings. Sample: Figure 1 a schematic representation of a wind energy apparatus; Figure 2 shows the sectional representation of the fixation according to the invention of a rotor blade in a rotor hub of a wind energy apparatus. (rotor blade connection) ^ Figure 3 is a schematic view of an end section of the rotor blade according to the invention of Figure 1; and Figure 4 is another schematic view of an end section of an alternative embodiment of a rotor blade according to the invention. The wind energy apparatus 1 represented in Figure 1 essentially comprises a tower 3 and a nacelle 5 fixed in the tower 5 to receive a generator 7 as well as a rotor directly connected with this 8. The rotor 9 has a rotor hub 11 as well as for example three rotor blades 2 fixed to the hub of the rotor 11. Due to the wind forces acting on the rotor blade 2, the hub of the rotor 11 is turned to drive the generator 7. The generator 7 constructed as The annular generator has a stator and an armature 15. The armature 15 is mounted together with the rotor hub 11 by means of the main supports 17 on a mounting peg 19, which is fixedly attached to the machine holder 21. The machine carrier 21 is pivotable in the tower 3 by means of an azimuth motor 23. In the machine carrier 21 an anemometer 27 is also fixed. Figure 2 shows in a sectional view a section of a rotor blade 2 of an energy apparatus. wind energy l, where it can be, for example, a wind energy apparatus of the type called horizontal axis. The rotor blade 2 partially shown in FIG. 2 is of a lightweight construction made of a composite material, epoxy resin reinforced with fibers and fixedly attached by means of a rotor connection 29 according to the present invention to the rotor hub 11. , where the rotor blade 2 is screwed with a peripheral flange section 4 in the shape of a T in its cross section, which in turn is rigidly connected with the rotor hub 11. The section of the rotor blade 2 shown in FIG. Figure 1 is like the periphery flange section 4 and essentially tubular in shape and is transformed, with increasing distance from the hub of the rotor 11 in the wing profile (not shown). A blade adapter or blade 31 is arranged between the rotor blade connection 29 and the rotor hub 11. With the aid of a blade adjusting motor, a rotor blade 2 can be combined with a blade connection 29 and an adapter of blade 31 rotate about the longitudinal axis of rotor blade 2.

FIG. 2 illustrates the enlargement on both sides according to the invention of the cross-section or thickening of the rotor blade 2 in the area of the base of the rotor blade 6, that is, in the example of FIG. embodiment in the end area of the section of the rotor blade 2 basically formed tubularly, which blade in the assembly state is connected to the flange section 4 of the rotor hub ll. In the opposite lateral areas of the base of the rotor blade 6, thickening sections 8, 10 are formed, which cause a widening of the cross section of the rotor blade 2 in the direction of the end area of the rotor blade 2. in the area of the base of the rotor blade, by means of the section widens basically by the thickening sections 8, 10 formed on both sides of the rotor blade 2, a high mechanical resistance is achieved there. The thickening sections 8, 10 can be made, for example, by adding layers of epoxy resin and additional fibers. In the area of the base of the rotor blade 6, several recesses in the form of blind holes 12, 14 are provided, which do not pass through completely but only partially to the rotor blade 2, which have a cylindrical shape and extend from the surface of the rotor blade to the inside of the rotor blade, the blind holes cylindrical 12 depth, which corresponds to approximately one third of the total thickness (cross section) of the rotor blade 2 in the area of the base of the rotor blade 6. Within the blind aggressors 12, 14, transverse bolts 16 are arranged and rolled. , 18 made of metal as running elements inside the rotor blade 2. The transverse bolts 16, 18 have a through bore provided with an internal thread. They act as clamping elements 20, 22 in the form of cylindrical bolts made of metal, when an external thread of the clamping elements 20, 22 is screwed into the internal thread of the transverse bolts 16, 18. The clamping elements 20, 22 they extend inside respective perforations 24, 26 provided inside the rotor blade 2, as well as inside the respective perforations 28,30 inside the flange section 4. By means of corresponding nuts 32, 34 placed on the inside. the external thread of the clamping or pulling elements 20, 22 and of the intermediate connection of a sleeve 36, 38 can the clamping elements 20, 22 be subject to high tensile forces and with that pull the rotor blade 2 fixedly to the section of flange 4 and thus to the rotor hub 11, so that a fixed connection between the rotor blade 2 and the rotor hub 11 occurs.

Figure 3 shows a view of the rotor blade 2 according to a first embodiment of the invention shown in Figure 2, where multiple clamping elements 20, 22 are arranged in opposite pairs 5 (Figure 2) spaced between Yes, in two concentric rows. In FIG. 3, perforations 24, 26 are recognizable in the rotor blade 2, which are disposed along two concentric circular rows. Figure 4 shows an alternative embodiment of the invention, in which the perforations 26, 24 t with this also the clamping or traction elements 20, 22 and the transverse bolts 16 18 are also arranged in two essentially concentric rows a the of the rotor blade base 6 of tubular shape, in both rows displaced from each other. It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the products to which it refers.

Claims (4)

1. CLAIMS Having described the invention as above, the content of the following is claimed as property: 1.- Alabe or rotor blade for a wind energy apparatus with at least one notch disposed in the area of the base of the rotor blade, which it essentially extends transversely to the longitudinal axis of the rotor blade to receive a transverse bolt or pin, which is connectable for connection of the rotor blade to a rotor hub of a wind power apparatus with a clamping traction element, characterized because, the notch only partially penetrates the rotor blade.
2. 2. Rotor blade according to claim 1, characterized in that the rotor blade in the region of the base of the rotor blade has a widened cross-section and the blind hole or the blind holes are arranged in the area of the section widened cross section.
3. 3. Rotor blade according to claim 2, characterized in that the cross section of the rotor blade is enlarged on both sides in the direction of the end section of the rotor blade on the side of the hub.
4. 4. Rotor blade according to claim 3, characterized in that the rotor blade has two opposite thickening sections in one piece with the rotor blade and the blind holes are arranged at least partially in the area of the rotor section. thickening. 5. - Rotor blade according to at least one of the preceding claims, characterized in that the rotor blade in the area of the base of the rotor blade has an end section in the shape of a rotor. 10 essentially tubular in which multiple blind holes are formed inside and out. 6. Rotor blade according to at least one of the preceding claims, characterized in that there are multiple single perforations with respective holes 15 blind, which extends in the direction of the longitudinal axis of the rotor blade, to receive two elements of traction or tightening unible with a bolt or transverse pin. 7. - Rotor blade according to at least 20 one of the preceding claims, characterized in that the blind hole or the blind holes in the essential have a cylindrical shape and have a depth that corresponds approximately to a third of the cross section of the rotor blade in the area of the base of the 25 rotor blade. T? A? - "" 5 * 8. - Reaffirming blade according to at least one of the lower claims, characterized in that, in essence, it consists of an epoxy resin bonded material reinforced with fiberglass 9. Rotor for a wind energy device with a rotor hub and at least one rotor blade fixed to the rotor hub, characterized in that the at least one rotor blade is constructed according to one of the preceding claims. 10. Rotor according to claim 9, characterized in that, the rotor hub has a flange section essentially T-shaped in the cross section, peripheral to connect the rotor blade, and the rotor blade is screwed with flange section 15 by means of tension or clamping elements, which are joined with transverse bolts anchored in the rotor blade. 11. Rotor according to claim 10, characterized in that, the multiple traction elements 20 are arranged in pairs parallel to each other and in two rows disposed essentially concentrically. 12. Rotor according to claim 11, characterized in that the traction elements of a row are offset with respect to the tensile elements of 25 the other row. Sxm® »? * ® s? &? ^^ __________ j _ ^^ _ s * ^ ^^^^^^^^^^^^^^ g