MX2008008210A - Levelling of root bushings on blades for wind turbines - Google Patents

Abstract

The present invention relates to a method of manufacturing a blade for a wind turbine, wherein the blade is made in one or more moulds;and wherein the blade has integrally moulded root bushings in the root of the blade for direct or indirect attachment to a hub in a wind turbine. The novel aspect of the invention is that the root bushings (203) in the root (201) of the blade are levelled by shortening of at least one of the root bushings prior to the blade being removed from a supporting mould (205). The invention further relates to a blade made in accordance with the method and a levelling unit (207) for levelling the root of the blade, wherein the levelling unit comprises means for mounting on a mould.

Description

LEVEL OF BASE BUSHING IN WIND TURBINES PALLETS DESCRIPTION OF THE INVENTION The invention relates to a method for manufacturing a blade for a wind turbine, wherein the blade is manufactured in one or more molds; and wherein the vane is integrally molded base bushings at the base of the vane for direct or indirect connection to a bucket in a wind turbine. In addition, the invention relates to a pallet made according to the invention. Finally, the method relates to a leveling unit for use in connection with the manufacture of a blade for a wind turbine wherein the blade is made of one or more molds; and wherein the vane has integrally molded base bushings at the base of the vane for direct or indirect connection to a bucket in a wind turbine.

BACKGROUND In the context of manufacturing blades for wind turbines, the manufacturing course is that the laminated pallet covers are molded into molds and subsequently assembled to form a complete pallet. In relation to the molding process, a number of base bushings with threads are distributed in the base of the pallet for use in the connection with the assembly in the wind turbine hub by means of bolts. In the context of this, it is important that the base bushes end in the same base bushing plane and, at the same time, it is important that the plane in whthe base bushing plane is located is the correct plane in relation to the pallet, since otherwise, it can mean that the pallet is mounted obliquely and that the bearing between the hub and the pallet is forced obliquely in this way. If all of the base bushings are not in the same base bushing plane, it may mean that some of the bushings are caused to bear more load than others, whconsiderably impairs the longevity of the bearing and therefore of the turbine. wind. Although tools are known designed to ensure that the base bushings are flat relative to the integral molding at the base of the paddle covers, the covers are deformed as they shrink with respect to the curing of the laminate material whmeans that the base bushings It can cause them to be oblique. This also means that it is impossible to predict the obliquity of the base bushings by simultaneously ending the different obliquity from one pallet to another. Currently, the above concern is solved when the base bushings are exceeded after molding finished and this procedure requires work by the finished pallet that is supported on a support, for example a pallet truck, after the mold is unloaded, after wha cylindrical router machine is mounted on the base of the pallet whit reduces the base bushings and in this way shortens some of the base bushings to produce this so that they end up in the same base bushing plane. The recessing procedure as such is carried out by a person who monitors the spark formation from the base bushings and when sparks are generated in all the base bushings is due to the fact that all the bushings end in a bush plane of common base that corresponds to the plane of recess. The problem with the previous method is that, after the mold is unloaded, the pallet gives way and is deformed due to the weight of the pallet itself and therefore the recess plane in relation to the pallet is no longer precise and homogeneous. This means that the base bushing plane can be oblique in relation to the pallet and the desired plane and also that the base bushing plane does not become a uniform plane either for pallets that do not end up in the wind turbine itself. Regarding the leveling of the base bushing plane frequently, in particular when large pallets of approximately 50 m are involved or greater, a very small tolerance in the surface uniformity of the order of ± 2/10 mm. In addition, a subsequent verification of the base bushing plane is problematic since it is performed in relation to points in the pallet.

OBJECTIVE AND DESCRIPTION OF THE INVENTION The objective of the invention is to provide a solution to the above problem. The present invention therefore relates to a method of manufacturing a vane for a wind turbine wherein the vane comprises laminated covers made in molds, wherein the covers are assembled to form a vane subsequent to the molding simultaneously which is supported by the mold of at least one shell, and wherein the blade has integrally molded base bushings at the base of the blade for attachment to a hub in a wind turbine. The base bushings at the base of the vane are leveled by shortening at least one of the base bushings before the vane is separated from the supporting mold. In this way it is ensured that the pallet is optimally supported during the leveling process since the mold supports the pallet uniformly over its entire surface. This ensures a more precise leveling through which a homogenous base plane is ensured. In addition, it also ensures a - Plane of uniform base bushing for different pallets as they are molded in the same mold, the support for different pallets is the same when they are molded in the same mold. When base bushes are leveled, it is not necessary to provide a base plate and therefore it is possible to handle the pallet from the base. In addition, the leveling can be carried out simultaneously when the pallet heals completely and in this way time is saved in relation to the total processing procedure of the pallet. According to one modality, leveling is carried out by grinding. By means of this shortening technique less heat is generated than by lowering and therefore it is possible to carry out the leveling more quickly, as opposed to the lowering where it is often performed very slowly to reduce the heating of the base bushings. According to one embodiment, the leveling is performed by a leveling unit mounted on the mold. In this way the leveling unit is secured on a stable platform and by allowing the leveling to be performed in relation to it, the risk of imprecise leveling is minimized. According to one embodiment, the leveling unit measures how much of the base bushings are going to shorten before leveling the base bushings. By measuring this, the leveling unit will be able, via a control, to determine this moment the leveling has finished and in this way the leveling procedure becomes automated and does not necessarily need to be monitored. The invention also relates to a wind turbine comprising a paddle made according to the method as described above. According to one modality a leveling check is made in relation to one or more points in the mold. The use of points in the mold as reference points for the verification of leveling is advantageous since in this way uniform and static reference points are ensured. This provides a uniform and precise leveling. The invention also relates to a leveling unit for use in connection with the manufacture of a blade for a wind turbine, wherein the blade is a laminated element composed of laminated covers made in molds, wherein the covers are subsequently assembled to form a pallet simultaneously where the latter is supported by the mold of a cover; and wherein the vane has base bushings integrally molded into the base for attachment to a hub in a wind turbine. The leveling unit comprises a means for joining on the mold to carry out that the base bushings at the base of the blade can be leveled by shortening at least one of the base bushings before the blade is separated from the support mold. In this way, the leveling unit is secured on a stable platform and allowing the leveling to be carried out in relation to it, the risk of imprecise leveling is minimized. According to one embodiment, the leveling unit comprises a grinding medium for shortening the base bushings. This shortening technique emits less heat than the recess and therefore the leveling can be carried out more quickly since, as regards recess, it is often necessary to do it very slowly to reduce the heating of the base bushings . According to one embodiment, the leveling unit comprises measuring units for measuring how short the base bushings should be shortened. By measuring this, the leveling unit will be able to determine, via a control, when the leveling should end and in this way the leveling procedure becomes automated and does not necessarily need to be monitored. According to one modality, the measurement units are optical meters. These meters are meters that They are able to measure with high precision and therefore comply with strict standards that are applied in relation to the leveling of the base bushings.

BRIEF DESCRIPTION OF THE DRAWINGS In the following, the invention will be described with reference to figures a to 2b, in which: the figure shows a blade for a wind turbine; Figure Ib shows the base, which is observed from the end of the blade, showing the base bushings; Figure 2a shows the base of a pallet before leveling, when the pallet is placed in a mold and where the leveling unit is mounted on the mold; Figure 2b shows the base of a pallet before leveling.

DESCRIPTION OF THE MODALITIES The figure shows a blade for wind turbine, where the base 103 is indicated. When the pallet is to be mounted in the hub of a wind turbine, it is base 103 that is fixedly mounted in the hub in contact therewith. Figure Ib shows the base 103 of the palette, which is observed from the end of the palette.

Here the base bushings 105 are illustrated and these bushings are used when the paddle is to be fixed to the hub. The number of bushings depends on the size of the pallet but they can be, for example between 60 and 90 bushings. With respect to the molding of the vane covers, the base bushings, which may be made of metal, are integrally mounted, evenly distributed along a circular cross-section of the base. For example, the bushings can be provided with threads, and in that case the palette can be fixed to the hub by mounting bolts through the hub and into the bushings. Figure 2a shows the base 201 of a pallet where the pallet is placed in a mold 205 and where couplings, hinges or the like are used to mount a leveling unit 207 in the mold. The leveling unit 207 has the purpose of leveling the base bushes 203 at the base of the pallet, the leveling unit levels when cutting part or all of the bushings with the effect that all are caused to end up in the same plane; the shortening as such is carried out, for example, by deburring or grinding. An example of the functionality of the leveling unit can be the following: 1. The pallet covers have been bonded by glue and are now supported mainly by the molds of one of the covers of the pallet. The mold for the pallet, in one embodiment, can remain on the upper pallet cover during leveling, so that the mold contributes to securing the cover, which is still supported on the mold. This assurance can contribute to further ensure support for the palette. Alternatively, the upper vane cover can be leveled from the mold in order to ensure in this way that the vane covers have been caused to correctly coincide with each other before the base bushings are leveled. 2. The leveling unit is secured by means of securing the support mold. 3. The leveling unit identifies the base bushing protruding further from the base and the base bushing protruding less from the base and, based on this, determining how much of the other base bushes should be shortened and for all Base bushes end up in the same plane. This identification procedure can be carried out, for example by the use of optical distance meters mounted on the leveling unit but other types of distance meters can also be used. 4. The leveling unit begins its leveling in the base bushing that protrudes further from the base and shortens the base bushings until the base bushing ends are in the same plane. The shortening is such that, according to - ¬ In one embodiment, it can be carried out by the ends of the base bushing that are shortened by grinding or cutting. 5. After shortening the base bushing ends so that all of the base bushing ends end up in the same base bushing plane, the leveling unit stops and the leveling procedure is finished. In a further step, however, it is conceivable that the leveling unit uses the optical distance meters to verify that the leveling is as desired. This verification can be done, for example, in relation to points in the mold. Figure 2b shows the base 201 of the pallet supported by the mold 205 after the leveling is completed by the leveling unit 207 of the base bushings 203. The pallet is now unloaded from the mold and taken for further processing. It will be understood that the invention, as described in the present specification and figures, the a 2b can be modified or changed and at the same time continue to be understood by the protective scope conferred by the following claims.

Claims (10)

1. Method of manufacturing a vane for a wind turbine, where the vane is made of one or more molds and where the vane has base bushings molded integrally in the base of the vane for direct or indirect connection to a bucket in a turbine wind, characterized in that the base bushings at the base of the vane are leveled by shortened from at least one of the base bushings before the vane is separated from the support mold.

Method as described in claim 1, characterized in that the leveling is carried out by a cutting process such as, for example, grinding.

3. Method as described in claims 1-2, characterized in that the leveling is performed by a leveling unit mounted on the mold.

Method as described in claim 3, characterized in that the leveling unit measures how much of the base bushings are to be shortened before the base bushings are leveled.

5. Method as described in claims 1-4, characterized in that a verification of the leveling is made in relation to one or more points in the mold.

6. Wind turbine comprising a pallet manufactured as described in the method of claims 1-5.

7. Leveling unit for use in connection with the manufacture of a blade for a wind turbine, wherein the blade is made of one or more molds; and wherein the vane has base bushings integrally molded into the base of the vane for direct or indirect connection to a hub in a wind turbine, characterized in that the leveling unit comprises a joining means for attachment to the mold to carry out the Base bushes at the base of the pallet are leveled by shortened from at least one of the base bushings before the pallet is separated from the support mold.

8. Leveling unit as described in claim 7, characterized in that the leveling unit comprises a cutting means, such as, for example, a grinding medium for shortening the base bushings.

9. Leveling unit as described in claims 7-8, characterized in that the leveling unit comprises measuring units for measuring how short the base bushings should be shortened.

10. Leveling unit as described in claim 9, characterized in that the measuring units are optical meters.