WO2016193297A1

WO2016193297A1 - Robot and working tool for performing assembly and maintenance operations in a sectioned tower

Info

Publication number: WO2016193297A1
Application number: PCT/EP2016/062362
Authority: WO
Inventors: Jens Nygaard LAURSEN
Original assignee: Total Wind A/S
Priority date: 2015-06-01
Filing date: 2016-06-01
Publication date: 2016-12-08

Abstract

Robot (1), for performing assembly and maintenance operations in a sectioned tower of a type where the tower sections are connected by a bolted flange joint comprising a circular internal flange (3) and a plurality of bolts (5), the robot (1) comprising; a. at least two trolleys (7), b. a connecting arrangement (9), and c. a controller (11), wherein said at least two trolleys (7) each comprises a conveying means, wherein each conveying means comprises a support configured for supporting the robot on said circular internal flange (3), wherein each support comprises at least one support point and wherein the supports in combination comprise at least three support points, wherein each trolley (7) is connected to the connecting arrangement (9), wherein the length of the connecting arrangement (9) is configured for positioning each support point at a distance from the centre of the flange (3) that exceed the internal radius of the flange (3), wherein the lay-out of the three support points that are farthest apart forms a triangle, wherein at least one trolley (7) is a driven trolley, wherein the conveying means of said driven trolley (7) comprises a drive configured for moving the trolleys tangentially along said internal flange, wherein said drive is operably connected to the controller (11), and wherein at least one trolley (7) comprises attachment means configured for attachment of a working tool (21) for performing the assembly and maintenance operations, and a working tool (21).

Description

Robot and working tool for performing assembly and maintenance operations in a sectioned tower

The current invention relates to a robot, for performing assembly and maintenance operations in a sectioned tower of a type where the tower sections are connected by a bolted flange joint comprising a plurality of bolts and a circular internal flange.

Moreover the present invention relates to a working tool for performing assembly and maintenance operations in a sectioned tower. Background

Horizontal axis wind turbines generally comprise a tower supporting a nacelle with a generator and a gearbox that are connected to a horizontal shaft with a rotor.

There is a desire towards increasing the rotor size because it enables an increase in the power output. An increased rotor size requires the tower to increase in height to allow for the increased rotor diameter and to place the rotor in the best wind regime. Towers have now reached a height in excess of 100 meters.

Towers consist of segments that are assembled during erection of the tower by placing one on top of the other until the final height is reached. The sections are joined through a flange connection with bolts and nuts that are tightened with a predefined torque or preload to hold the sections together.

As an example a 100 meter tower may have a diameter that tapers from 6-8 meters at the root to 3 meters at the top. A section joint may comprise in excess of 100 bolts each weighing approximately 20 kg. Thus, at least 2,000 kg of bolts not including the weight of the associated nuts and washers must be transferred from ground level to each section joint. This can be done by placing the bolts in the bolt holes of the flange of the upper section before it is lifted in position upon a lower section. During positioning of the upper section the bolts can be used to align the flanges of the upper and lower sections. Then a manual procedure where the bolts are removed, turned over and inserted into the flanges with the bolt heads facing downwards. The nuts are installed and preliminary tightened. When all bolts are installed the procedure of tightening the bolts to its final setting is completed.

The installation personnel may for example use a pneumatic, electrical or hydraulic torque wrench. EP 2 607 685 A1 discloses a bolt tightening robot for wind turbines. The robot moves horizontally along the flange and bolts down the nut bolts one at a time.

The available methods have two major disadvantages. The first disadvantage is the aspect of ergonomics in handling the bolts with a weight close to the maximum allowable lifting capability of personnel. There usually is a limited time available to tighten the bolts in a section joint in order to limit the duration of the lift of the tower section. To meet this requirement, a high number of personnel are needed in order to expedite the bolt installation without causing too much strain on the personnel. The second disadvantage is related to safety. When working in a tower, and especially towers of multiple sections, personnel working at lower levels are at risk of injuries caused by objects dropped from higher levels. Therefore it is only safe to work at one level at a time to eliminate this risk.

An object of the present invention is therefore to provide an apparatus that is capable of mitigating the above mentioned disadvantages.

Summary of the invention According to the present invention, this is achieved by a robot, for performing assembly and maintenance operations in a sectioned tower of a type where the tower sections are connected by a bolted flange joint comprising a circular internal flange and a plurality of bolts, the robot comprising;

a. at least two trolleys ,

b. a connecting arrangement, and

c. a controller,

wherein said at least two trolleys each comprises a conveying means, wherein each of said conveying means comprises a support configured for supporting the robot on said circular internal flange, wherein each support comprises at least one support point and wherein the supports in

combination comprise at least three support points, wherein each trolley is connected to the connecting arrangement, wherein the length of the connecting arrangement is configured for positioning each support point at a distance from the centre of the circular internal flange that exceeds the internal radius of the circular internal flange, wherein the lay-out of the three support points that are farthest apart forms a triangle, wherein at least one trolley is a driven trolley, wherein the conveying means of said driven trolley comprises a drive configured for moving the trolleys tangentially along said circular internal flange, wherein said drive is operably connected to the controller, and wherein at least one trolley comprises attachment means configured for attachment of a working tool for performing the assembly and maintenance operations.

Moreover, according to the present invention, this is achieved by a working tool for performing assembly and maintenance operations in a sectioned tower, the tool comprising a bolt holder configured for holding a bolt and an overturner configured for overturning the bolt, wherein the bolt holder comprises a bolt head engager configured for holding the bolt by its head. It is herewith achieved that the robot may position a working tool at various positions along the flange joint between the tower sections. The working tool can then perform assembly and maintenance operations.

The configuration of the support and the connecting arrangement according to the invention prevents the robot from accidentally falling down to a lower level in the tower. Moreover, the controller enables autonomous operation of the robot such that the area in which the root operates may be vacated. This improves the safety of operation. Assembly and maintenance operations can be executed at multiple horizontal levels in the tower without increasing the risk of injuries to personnel.

Moreover it is achieved with the working tool that assembly and maintenance operations such as installing bolts and nuts can be performed with minimal interference by personnel.

In the present application the term "robot" is a mechanism guided by automatic controls.

In the present application the terms "supporting or supported on" includes support by direct contact or contactless support such as support by magnetic means or other means capable of applying a force to the conveying means with a resultant vector that is of the same magnitude as the force of gravity acting on the robot but directed opposite the force of gravity.

The support points are locations of support of the robot by contact with the flange or contactless support provided for example by an electromagnetic device.

In one embodiment of the invention the support may comprise more than three (3) support points, wherein the lay-out of the three support points that are farthest apart forms a triangle.

This forms a stable support for the robot. For example the support may comprise four (4), five (5), six (6), seven (7), eight (8), nine (9), ten (10), eleven (1 1 ), twelve (12) or more support points.

In an embodiment of the invention the connecting arrangement comprises a length adjuster, for adjusting the length of the connecting arrangement. It is herewith achieved that the robot can be used with flanges of different diameters. This is especially advantageous with wind turbine towers that taper from bottom to top.

According to a further embodiment, the robot according to the invention is characterized in that, each support comprises at least one support wheel and wherein the supports in combination comprise at least three support wheels.

It is herewith achieved that the robot can be conveyed along the flange in a particularly straight forward manner.

Moreover the friction between the wheel and the face of the flange is relatively small. Therefore the power required to move the robot is small. According to a further embodiment, the robot according to the invention is characterized in that, the support wheels is configured with a horizontal axis of rotation, and wherein each support comprises a guide wheel configured with a vertical axis of rotation.

It is herewith achieved that the robot can be prevented from leaving the flange by accident as the guide wheel may be biased against the inside of the flange.

In the present application the term "horizontal" and "vertical" refers to the intended in use orientation of the robot.

According to a further embodiment, the robot according to the invention is characterized in that, the drive comprises a motor, wherein the motor is operably connected to said at least one support wheel of its driven trolley. It is herewith achieved that the robot may move automatically when the motor is being operated.

In one embodiment the motor is an electrical motor.

In the present application the term "motor" refers to a device that changes energy into mechanical motion. The energy may be provided in the form of electricity, pressurized air, pressurized fluid (for example oil or water), flammable substrate for combustion or other suitable form.

According to a further embodiment, the robot according to the invention is characterized in that, the controller comprises a positioner, wherein the positioner comprises locating means for locating the position of a target bolt of the plurality of bolts, and wherein the positioner is operably connected to the controller, wherein the controller is configured for operating the drive, for positioning the working tool.

It is herewith achieved that the working tool may be precisely positioned. The positioner records the position of the target bolt and based on the knowledge of the lay-out it is possible to establish the position of items in the tower and the desired location of the working tool.

The target bolt may be the bolt that is subject for a specific procedural step.

Alternatively, the trolley is moved to a desired position and the drive is disconnected. Then the positioner will establish the position of the target bolt using the locating means. Based on that information the drive is used to angular positioning of the trolley and thereby the working tool.

In an embodiment the working tool comprises means to position the working tool in the x-, y-, z- direction in relation to the bolts when the trolley is stationary in a desired position. According to a further embodiment, the robot according to the invention is characterized in that, the robot comprises at least one working tool, for performing assembly and maintenance operations.

It is herewith achieved that the working tool is provided as part of the robot. In an embodiment of the invention the working tool is selected among but not limited to tools for applying surface treatment to the tower and tower components, tools for handling and installing bolts and nuts, tools for performing visual- and non-destructive inspection of the tower and tower components and tools for cleaning the tower and tower components. According to a further embodiment, the robot according to the invention is characterized in that, the working tool comprises a bolt holder configured for holding a bolt and an overturner configured for overturning the bolt, wherein the bolt holder comprises a bolt head engager configured for holding the bolt by its head. It is herewith achieved that the handling of the bolts may be automated. The robot is able to pick up, with the working tool, a bolt from the circular internal flange as the tower is lifted to the respective section. The bolt is overturned and inserted into the flange joint from below with the bolt end facing upwards.

According to a further embodiment, the robot according to the invention is characterized in that, the bolt head engager comprises an electromagnet.

It is herewith achieved that the bolt may be held in a particularly simple manner.

In an embodiment the bolt holder is a cup with an internal diameter that exceeds the circumscribed circle about the bolt. In the bottom of the cup an electromagnet is placed, when the bolt head is located in the cup the electromagnet is turned on and the bolt attaches to the bolt holder. According to a further embodiment, the robot according to the invention is characterized in that, the overturner comprises a retraction mechanism configured for positioning the bolt head engager radially in relation to the circular internal flange, a rotation mechanism configured for rotating the bolt head engager about a radius and/or a tangent of the circular internal flange and an elevation mechanism configured for moving the bolt head engager vertically in relation to the flange, wherein the retraction mechanism, the bolt head engager, the rotation mechanism and the elevation mechanism is operably connected to the controller. It is herewith achieved that the working tool may be positioned in the x, y, z direction.

According to a further embodiment, the robot according to the invention is characterized in that, the working tool comprises a nut magazine configured for containing a plurality of nuts, and a nut engager configured for holding a nut.

It is herewith achieved that the application of nuts may be performed without human intervention, except for filling the nut magazine.

According to a further embodiment, the robot according to the invention is characterized in that the nut engager comprises an electromagnet. It is herewith achieved that the nut may be held in a particularly simple manner.

In an embodiment the bolt holder is a cup with an internal diameter that exceeds the circumscribed circle about the nut. In the bottom of the cup an electromagnet is placed, when the bolt head is located in the cup the electromagnet is turned on and the bolt attaches to the bolt holder.

According to a further embodiment, the robot according to the invention is characterized in that, the nut engager comprises a nut positioning

mechanism, wherein the nut positioning mechanism comprises an elevator configured for vertical positioning of the nut engager in relation to the nut magazine and the bolt end respectively, a locator configured for horizontal positioning of the nut engager in relation to the nut magazine and the bolt end respectively, and a nut tightener configured for rotating the nut about the bolt.

It is herewith achieved that the nut may be automatically positioned in relation to the bolt end.

According to a further embodiment, the working tool according to the invention is characterized in that, the working tool comprises a nut magazine configured for containing a plurality of nuts, and a nut engager configured for holding a nut.

It is herewith achieved that the robot may be operated autonomously.

It should be emphasized that the term "comprises/comprising/comprised of when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

Brief description of the drawings

The invention will be explained in more detail below with reference to the accompanying drawing, where:

Fig. 1 shows a plan view of a robot according to the invention and a flange of a sectioned tower, fig. 2-14 shows a section view of a trolley 7 according to the invention

during the steps required to install a bolt in the flange joint, and fig. 15-18 shows different embodiments of the robot according to the

invention. In the following, the invention will be described in greater detail with reference to embodiments shown by the enclosed figures. It should be emphasized that the embodiments shown are used for example purposes only and should not be used to limit the scope of the invention.

Detailed description of the embodiments

In the explanation of the figures, identical or corresponding elements will be provided with the same designations in different figures. Therefore, no explanation of all details will be given in connection with each single figure/embodiment.

Fig. 1 shows a plan view of a robot 1 according to the invention and a flange 3 of a sectioned tower. The flange 3 has a plurality of openings configured to receive a corresponding plurality of bolts 5, see fig. 2.

The robot comprises two trolleys 7, a connecting arrangement 9 and a controller 1 1 .

In the embodiment shown the trolleys 7 have an angular spacing of 180°.

In the embodiment shown each trolley 7 comprise a U-shaped beam arrangement 10 from which the various items of the trolley are suspended.

Each trolley 7 comprises conveying means. In the embodiment shown the conveying means of each trolley comprises a support in the form of two (2) support wheels 13. Thus, the total number of support wheels 13 for the trolleys 7 in combination is four (4). Each support wheel 13 is in contact with the face of the flange 3. Each support wheel 13 is arranged with a horizontal axis of rotation. Moreover, each support wheel 13 is arranged such that its axis of rotation is substantially tangential to the flange 3 at its specific location. The support wheels 13 are radially spaced such that the robot 1 does not tilt during the normal operation scheme.

In the embodiment shown the support of each trolley comprise two (2) guide wheels 15 configured with a vertical axis of rotation. The guide wheels 15 may be in contact with the side of the flange 3 to guide the robot 1 an avoid it becoming misaligned in relation to the flange 3.

In the embodiment shown each trolley 7 is a driven trolley. The conveying means of each trolley 7 comprises a drive in the form of an electrical motor 17 that is connected to one of the support wheels 13 of each trolley 7 through a shaft. When operating the electrical motors 17 in concert the robot is able to travel 360° around the flange in both directions.

Each trolley 7 comprises attachment means 19 for a working tool 21 .

In the embodiment shown the two trolleys 7 are identical. However, they can be configured differently, for example to accommodate different working tools 21 .

For example the working tool 21 on one trolley 7 can be a tool to install and preliminary tighten bolts and nuts and on the other trolley can be a tool to apply the final torque or preload to the nuts.

The trolleys are connected to a connecting arrangement 9 that maintains the position of the two trolleys 7 in relation to each other during operation.

The connecting arrangement 9 comprises two beam members 23 that in combination stretch across the centre of the flange 3 between the two trolleys 7.

In the embodiment shown the connecting beam 23 further comprises a length adjuster 25. The length adjuster 25 is configured for adjusting the length of the connecting arrangement 9 and thus, the spacing of the trolleys 7 and ultimately the position of the support in relation to the flange. The length adjuster 25 enables the robot to be used with flanges of different diameter by changing the spacing of the trolleys 7.

The controller 1 1 comprises a positioner 27; see fig. 2 for locating the position of a target bolt. The controller gathers positon data from the positioner 27 process the data and based on this information and preprogrammed algorithms operates the electrical motor 17 and the working tool 21 accordingly.

Fig. 2-14 shows a section view of a trolley 7 according to the invention during the steps required to install a bolt in the flange joint. The trolley 7 comprises a beam arrangement 12 that provides a base for the various parts that are located at the trolley 7.

The working tool 21 comprises a bolt holder with a cup-shaped bolt head engager 29 with an electromagnet for holding the bolt 5 and an overturner with a rotation mechanism 31 configured for rotating bolt head engager 29 with the bolt 5 about a horizontal axis for overturning the bolt 5. In the current embodiment, the horizontal axis around which the bolt is rotated is a radius of the circular internal flange. However, in another embodiment, the horizontal axis could also be a tangent of the circular internal flange or a combination of the radius and tangent. The overturner further comprises a retraction mechanism 33 with a linear actuator for positioning the bolt head engager radially in relation to the flange 3 and an elevation mechanism 35 for positioning the bolt head engager 29 vertically.

The bolt head engager 29, the rotation mechanism 31 , the retraction mechanism 33 and the elevation mechanism 35 are all operably connected to the controller 1 1 .

The working tool comprises a nut magazine (not shown), configured for containing a plurality of nuts, and a nut engager 37, that is omitted for clarity on fig. 3-9 and that can best be seen on fig. 10 to 14, configured for holding a nut 39, see fig. 10 to 14.

The nut engager 37 comprises a nut positioning mechanism that comprises an elevator 41 configured for vertical positioning of the nut engager 37 in relation to the nut magazine (not shown) and the bolt end respectively, a locator 43 configured for horizontal positioning of the nut engager 37 in relation to the nut magazine and the bolt end respectively, and a nut tightener 45 configured for rotating the nut 39 about the bolt 5.

On fig. 3-14 the guide wheel 15 and the electrical motor 17 are omitted for clarity.

Fig. 2 shows a starting step for the assembly of two tower sections. The bolt 5 has been inserted with the bolt head facing upwards in the uppermost flange 3 before the upper tower section was lifted to its current positon on top of the lower tower section. Fig. 3 shows a step where the positioner 27 in the form of a camera has moved horizontally to find the location of the target bolt to establish the position of the trolley 7.

Fig. 4 shows a step where the bolt head engager 29 .engages the bolt 5.

Fig. 5 shows a step where the bolt 5 is retracted. In fig. 6 the bolt 5 is retracted and moved to the space between the legs of the beam arrangement 12, where it is possible to rotate the rotation mechanism 31 to overturn the bolt 5 - this action is shown on fig. 7.

In fig. 8 the bolt has been moved vertically so that it may pass the lowermost flange 3 when moved to the position of the bolt hole. In fig. 9 the bolt 5has been co-axially aligned with the bolt hole.

In fig. 10 the bolt 5 has been inserted with the bolt end facing upwards. In fig. 1 1 the locater 43 has moved the nut 39 in a position where it Is coaxially aligned with the bolt shaft.

In fig 12 the elevator has moved the nut 39 into position and the nut tightener 45 has turned to nut 39 such that the thread has been engaged. In fig. 13 the electromagnets of the bolt head engager and the nut engager have been turned off.

In fig. 14 the nut and bolt head engager has moved to the starting position.

Fig. 15-18 shows different embodiments of the robot 1 according to the invention. The embodiment in fig 15 has a connecting arrangement 9, wherein the beam members comprise a central ring 47, such that the centre of the flange 3 is free.

The central ring 47 could also be located off-centre.

In some wind turbines there is a central power cable extending from the nacelle to the ground level. This embodiment ensures that the power cable remains untouched by the robot 1 .

The embodiment in fig. 16 comprises three trolleys 7.

In this embodiment the assembly or maintenance operation can be completed quickly because the extra trolley 7 increases the capacity. Alternatively each trolley may have a different tool allowing the robot to perform different operations.

The embodiment in fig. 17 comprises four trolleys 7.

This further increases the capacity of the robot 1 or the ability to carry different tools of different operations. The embodiment in fig. 18 has a connecting arrangement that comprises straight beam members 23 that are connected in a triangular lay-out.

This enables a power cable as previously discussed, to pass through the robot 1 . It is to be noted that the figures and the above description have shown the example embodiments in a simple and schematic manner. The internal electronic and mechanical details have not been shown since the person skilled in the art should be familiar with these details and they would just unnecessarily complicate this description.

Claims

1 . Robot, for performing assembly and maintenance operations in a sectioned tower of a type where the tower sections are connected by a bolted flange joint comprising a circular internal flange and a plurality of bolts, the robot comprising;

a. at least two trolleys ,

b. a connecting arrangement, and

c. a controller,

combination comprise at least three support points, wherein said at least two trolleys are connected to the connecting arrangement, wherein the length of the connecting arrangement is configured for positioning each of said at least three support points at a distance from the centre of the circular internal flange that exceeds the internal radius of the circular internal flange, wherein the lay-out of the three support points that are farthest apart forms a triangle, wherein at least one trolley is a driven trolley, wherein the conveying means of said driven trolley comprises a drive configured for moving the trolleys tangentially along said circular internal flange, wherein said drive is operably connected to the controller, and wherein at least one trolley comprises attachment means configured for attachment of a working tool for performing the assembly and maintenance operations.

2. Robot according to claim 1 , wherein each support comprises at least one support wheel and wherein the supports in combination comprise at least three support wheels located at the support points.

3. Robot according to claim 2, wherein the support wheels are configured with a horizontal axis of rotation, and wherein each support comprises a guide wheel configured with a vertical axis of rotation.

4. Robot according to any of claims 2 or 3, wherein the drive comprises a motor, wherein the motor is operably connected to said at least one support wheel of its driven trolley.

5. Robot according to any one of the previous claims, wherein the connecting arrangement comprises a length adjuster, for adjusting the length of the connecting arrangement.

6. Robot according to any of the previous claims, wherein the controller comprises a positioner, wherein the positioner comprises locating means for locating the position of a target bolt of the plurality of bolts, and wherein the positioner is operably connected to the controller, and wherein the controller is configured for operating the drive, for positioning the working tool.

7. Robot according to any of the previous claims, wherein the robot comprises at least one working tool, for performing assembly and

maintenance operations.

8. Robot according to any of the previous claims, wherein the working tool comprises a bolt holder configured for holding a bolt and an overturner configured for overturning the bolt, wherein the bolt holder comprises a bolt head engager configured for holding the bolt by its head.

9. Robot according to claim 8, wherein the bolt head engager comprises an electromagnet.

10. Robot according to claim 8 or 9, wherein the overturner comprises a retraction mechanism configured for positioning the bolt head engager radially in relation to the circular internal flange, a rotation mechanism configured for rotating the bolt head engager about a radius and/or a tangent of the circular internal flange and an elevation mechanism configured for moving the bolt head engager vertically in relation to the circular internal flange, wherein the bolt head engager, the retraction mechanism, the rotation mechanism and the elevation mechanism are operably connected to the controller.

1 1 . Robot according to any of claims 7 to 10, wherein the working tool comprises a nut magazine configured for containing a plurality of nuts, and a nut engager configured for holding a nut.

12. Robot according to claim 1 1 , wherein the nut engager comprises an electromagnet.

13. Robot according to claim 1 1 or 12, wherein the nut engager comprises a nut positioning mechanism, wherein the nut positioning mechanism comprises an elevator configured for vertical positioning of the nut engager in relation to the nut magazine and the bolt end respectively, a locator configured for horizontal positioning of the nut engager in relation to the nut magazine and the bolt end respectively, and a nut tightener configured for rotating the nut about the bolt.

14. Working tool for performing assembly and maintenance operations in a sectioned tower, the tool comprising a bolt holder configured for holding a bolt and an overturner configured for overturning the bolt, wherein the bolt holder comprises a bolt head engager configured for holding the bolt by its head and wherein the overturner comprises a retraction mechanism configured for positioning the bolt head engager radially in relation to the circular internal flange, a rotation mechanism configured for rotating the bolt head engager about a radius and/or a tangent of the circular internal flange and an elevation mechanism configured for moving the bolt head engager vertically in relation to the circular internal flange, wherein the retraction mechanism, the bolt head engager, the rotation mechanism and the elevation mechanism are operably connected to the controller.

15. Working tool according to claim 14, wherein the working tool comprises a nut magazine configured for containing a plurality of nuts, and a nut engager configured for holding a nut.