The invention relates to a blade access arrangement for a rotor blade of a wind power plant having a tower, the arrangement comprising a platform, tower guide means for guiding the platform against the tower, a bar arrangement capable of being displaced in relation to the platform and connecting the platform with the tower guiding means, said blade access arrangement comprising a hoisting arrangement for hoisting the blade access arrangement up and down.
From WO 2009/121792 A2 such a blade access arrangement is known, where a suspendable maintenance platform for accessing a blade of a wind turbine. The platform includes arms for holding a maintenance unit, a frame onto which each arm is movably attached in a joint enabling planar movement, and means for supporting the frame in relation to the wind turbine tower. The maintenance unit is slidably attached to the arms that are configured for positioning the platform in relation to the blade, and wherein the frame is configured to be in close proximity to the turbine tower.
WO 2017/215711 A1 discloses an inspection device for a rotor blade having a maintenance chamber through which a rotor blade can pass vertically through a floor opening and a roof opening. The maintenance chamber is arranged on a supporting frame, and the supporting frame is connected to a bracing frame, which bracing frame can be supported on the tower of the wind turbine. By moving the bracing frame relative to the supporting frame it is possible to change the position of the maintenance chamber in relation to the tower of the wind turbine, keeping the maintenance chamber in a distance from the tower allowing the rotor blade running through the maintenance platform.
The objective of the invention is to provide a blade access arrangement where the platform can access the blade tip, which is positioned in a distance from the tower greater than other parts of the blade and where the platform in a transport situation between wind power plants can be reduced in size in such a way the whole arrangement can be transported on a trailer or on other suitable vehicle.
This objective is solved by a blade access arrangement as described above where the bar arrangement comprises an extension beam connected to the bar arrangement via a hinge.
Hereby it is possible to reduce the length of the inner beam by folding the extension beam into a transport position.
In an embodiment, the bar arrangement comprises a pair of telescopic beams comprising outer beams and inner beams.
The beam guides can be connected to the platform via pivot points.
Hereby is achieved, that the beams can have a long range in an operative configuration and can at the same time have a short extent in a transport configuration.
In an embodiment, the outer beams are capable of being displaced in beam guides in a longitudinal direction of the outer beams and in relation to the platform.
Hereby is achieved, that the beams can have an even longer range in an operative configuration and can at the same time limiting the extent of the beams in a transport configuration.
In an embodiment, the beam guides are fastened to the platform.
In an embodiment, the beam guides can be fastened to an underside of the platform.
In an alternative embodiment, the beam guides can be fastened to an upper side of the platform.
Hereby is achieved that the center of gravity is located low in the platform.
In an embodiment the inner beams capable of being displaced inside and in a longitudinal direction of the outer beams, and that the extension beams are provided at an end of the inner beams being the end pointing away from the tower guide.
Hereby it is possible to move the platform to a position where it is possible to access the tip of the blade, which tip is the point of the blade having the largest distance from the tower and at the same time keeping a size of the platform making it possible that the whole arrangement can be transported on a trailer or on other suitable vehicle.
In an embodiment, the extension beam is connected via the hinge to the inner beams and the hinge is placed in an upper part of the beam and having a substantial horizontal axis.
Hereby it is possible to reduce the length of the inner beam by folding the extension beam from a substantially horizontal position into a substantial upright position along an end of the platform. Hence the extension beam is folded up along the end of the platform, so the extension beam points up in the air.
In an embodiment, the extension beam is connected via the hinge to the inner beams and the hinge is placed in an outer part or side of the beam and having a substantial vertical axis.
Hereby it is possible to fold the extension beam along sides of the platform.
In an embodiment, the beams on the opposite side in relation to the hinge are provided with locking means, such as a securing split, bolt or similar.
Hereby is secured that the beam do not fold unintentionally.
In an embodiment, wheels, rollers or bushings are provided between the inner and outer beams.
Hereby it is possible for the inner and outer beams to be displaced smoothly in relation to each other.
In an embodiment, the inner beams at one end are provided with a stop for abutment against the beam guides.
In an embodiment, at least one of the beam guides is provided with a motor or drive for driving a wire, which wire in one end is attached to the beam guide at a first wire anchoring point, the other end of the wire being attached to the beam guide at a second wire anchoring point on the opposite side of the beam guide in relation to the first wire anchoring point, said wire between its ends is attached to the anchoring points and routed from the motor or drive to the anchoring points via a number of pulleys, said wire, between the ends of the wire, is wound with a number of windings around a pulley, wheel or capstan of the motor.
Hereby is established a drive for moving the beams in a telescopic way in relation to each other.
In an embodiment, the wire drive extends the beams and when reversing the drive slackening the wire, the beams retracts into each other due to the weight of the blade access arrangement forcing the platform towards the tower.
In an embodiment, a tensioning element is provided between the wire and at least one of the anchoring points.
The tensioning element can be a resilient member, a spring or a gas spring.
Hereby is achieved that the wire is provided with sufficient tension going from a folded configuration to an active configuration, where the extension bars are positioned in longitudinal extension of the inner bars.
In an embodiment each beam or bar arrangement is provided with a motor or a drive, which motors or drives are synchronized to ensure a symmetrical movement of the displaceable telescopic connections.
Hereby it is possible to move the platform along an axis in a radial direction of the tower.
In an embodiment, the (beams are provided with a square or rectangular cross section.
In an alternative embodiment, the beams are provided with a triangular or trapezoidal cross section.
In an embodiment, the telescopic beams can be lattice beams.
Hereby it is possible to provide strong telescopic beams and at the same time keep the weight low.
In an embodiment, the bar arrangement is connected to the tower guide means via pivot points.
Hereby the ends of the telescopic beams together with the tower guide means can take up any irregularities or change in shape from the tower surface.
Effects and features of the different embodiments are to a large extent analogous to those described above in connection with the first embodiment.
The present disclosure will become apparent from the detailed description given below. The detailed description and specific examples disclose preferred embodiments of the disclosure by way of illustration only. Those skilled in the art understand from guidance in the detailed description that changes and modifications may be made within the scope of the disclosure.
Hence, it is to be understood that the herein disclosed disclosure is not limited to the particular component parts of the device described or steps of the methods described since such device and method may vary. It is also to be understood that the terminology used herein is for purpose of describing particular embodiments only, and is not intended to be limiting. It should be noted that, as used in the specification and the appended claim, the articles “a”, “an”, “the”, and “said” are intended to mean that there are one or more of the elements unless the context explicitly dictates otherwise. Thus, for example, reference to “a unit” or “the unit” may include several devices, and the like. Furthermore, the words “comprising”, “including”, “containing” and similar wordings does not exclude other elements or steps.
The above objects, as well as additional objects, features and advantages of the present disclosure, will be more fully appreciated by reference to the following illustrative and non-limiting detailed description of example embodiments of the present disclosure, when taken in conjunction with the accompanying drawings.
The present disclosure will now be described with reference to the accompanying drawings, in which preferred example embodiments of the disclosure are shown. The disclosure may, however, be embodied in other forms and should not be construed as limited to the herein disclosed embodiments. The disclosed embodiments are provided to fully convey the scope of the disclosure to the skilled person.
The blade access arrangement 1 comprises a platform 2. The platform 2 has sides extending from a front end to a back end of the platform 2 and is connected to tower guide means 3, which rest against the tower. The tower guide means 3 can be provided with wheels or rollers 21 so that the tower guide means 3 can guide the platform 2 along the tower. The tower guide means 3 are connected to the platform 2 by means of a bar arrangement 4, 5. The bar arrangement 4, 5 comprises an extension beam 12, 13 connected to the bar arrangement 4, 5 via a hinge 14.
In an embodiment the bar arrangement 4, 5 connects the platform 2 with the tower guiding means 3 via beam guides 10, 11. A hoisting arrangement 22 for hoisting the blade access arrangement 1 up and down is provided. The hoisting arrangement 22 comprises a pair of hoisting means 22 placed on each side of the platform 2. The hoisting arrangement 22 comprises a further hoisting means 22, which is placed on a hoisting arm at the back end of the platform 2 or placed on the back end of the platform 2. The hoisting arm can be connected pivotably to the back end of the platform 2, the back end of the platform 2 being the end closest to the tower guide means 3.
The platform 2 can comprise a number of sub-platforms, where one sub-platform further can be divided into two sub-platform parts for easy access of a wind turbine blade into the center of the platform 2 by opening the platform 2 for encircling the blade.
When the platform 2 is in closed position an opening is provided in centre of the platform 2 through which opening a wind turbine blade can extend.
Changing shape or configuration of the platform 2 can be done by use of actuators or like equipment positioned between sub-platforms or between sub-platforms and frames for a decking.
The tower guide means 3 is in an embodiment shown in
The telescopic beams 4, 5 comprises in an embodiment, for example shown in
The extension beams 12, 13 are in an embodiment as shown in
In an embodiment, at least one of the beam guides 10, 11 is provided with a motor or drive 16 for driving a wire 17, which wire 17 in one end is attached to the beam guide 11 at a first wire anchoring point 29a. The other end of the wire 17 is attached to the beam guide 11 at a second wire anchoring point 29b on the opposite side of the beam guide 11 in relation to the first wire anchoring point 29a. The wire 17 is between its ends attached to the anchoring points 29a, 29b and routed from the motor or drive 16 to the anchoring points 29a, 29b via a number of pulleys 23, 24, 25, 26, 27, 28. Between the ends of the wire 17, the wire 17 is wound with a number of windings around a pulley, wheel or capstan of the motor 16, ensuring a firm grip between the wire 17 and the pulley, wheel or capstan of the motor 16.
In
Hereby, the wire 17 is connected to the motor or drive 16 and to the anchor points 29a, 29b in such a way that when the pulley, wheel or capstan of the motor 16 pulls the wire 17 in one direction the telescopic beams 4, 5 are retracted and when the pulley, wheel or capstan of the motor 16 changes direction of rotation, the wire is pulled in an opposite direction and thereby the telescopic beams 4, 5 are extended.
The wire 17 being looped around a number of sets of pulleys 23, 24, 25, 26, 27, 28 also leads to the effect that the pulleys acts as a pulley block system.
Hereby is achieved that the motor can move the telescopic beams in and out using less power and with a lower speed.
In an embodiment a tensioning element (not shown) is provided between the wire 17 and at least one of the anchoring points 29a, 29b for pre-tensioning of the wire 17 in such a way that when folding the extension beams 12, 13 from a transport position into an active position where the extension beams 12, 13 are positioned extending longitudinally from the inner beams 8, 9, the wire 17 will have a suitable tensioning. Hereby meaning that the wire 17 do not slacken in such an extent that the wire 17 no longer engages with the pulleys 23, 24, 26, 27, 28.
The tensioning element can be a resilient element such as a spring element, a gas spring or another suitable resilient element for tensioning the wire.
The beams 4, 5 can have a square or rectangular cross section.
In an alternative embodiment, the beams 4, 5 can have a triangular or trapezoidal cross section.
In an embodiment, the telescopic beams can be lattice beams.
The beams 4, 5 being lattice beams reduces the overall weight of the blade access arrangement 1.
A number of wheels, rollers or bushings 19, 20 is provided between the inner 8, 9, 12, 13 beams and outer beams 6, 7 in order to facilitate relative movement between the beams.
Between the platform 2 and the telescopic beams 4, 5 one or more pair of beam guides 10, 11 are provided. The beam guides 10, 11 allows the beams 4, 5 to be displaced in a crosswise direction in relation to a longitudinal direction of the beams 4, 5. The beam guides 10, 11 are also provided with wheels or rollers 19, 20 to facilitate relative movement between the outer beams 6, 7 and the beam guides 10, 11 in a lengthwise direction in relation to the beams 6, 7 and in relation to the platform 2.
The beam guides 11 can be connected to the platform 2 via pivot points 30.
In an embodiment, the beam guides 10, 11 can be fastened to an underside of the platform 2.
In an alternative embodiment, the beam guides 10, 11 can be fastened to an upper side of the platform 2.
The person skilled in the art realizes that the present disclosure is not limited to the preferred embodiments described above. The person skilled in the art further realizes that modifications and variations are possible within the scope of the appended claims. Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed disclosure, from a study of the drawings, the disclosure, and the appended claims.
Number | Date | Country | Kind |
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PA 2020 70788 | Nov 2020 | DK | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2021/082245 | 11/19/2021 | WO |