U.S. patent application number 13/001149 was filed with the patent office on 2011-06-02 for device for enabling access to a wind turbine.
This patent application is currently assigned to PP ENERGY APS. Invention is credited to Paul Teichert.
Application Number | 20110127109 13/001149 |
Document ID | / |
Family ID | 41445007 |
Filed Date | 2011-06-02 |
United States Patent
Application |
20110127109 |
Kind Code |
A1 |
Teichert; Paul |
June 2, 2011 |
DEVICE FOR ENABLING ACCESS TO A WIND TURBINE
Abstract
A device 1 for enabling access to a rotor blade 54 of a wind
turbine, said device being adapted for being moved in the
longitudinal direction of the rotor blade 54, the device comprising
a frame 2, means for supporting and guiding the device in relation
to the rotor blade, means for lowering and/or lifting the device in
relation to the rotor blade, wherein said frame 2 comprises a first
end and a second end, wherein said means for supporting and guiding
the device in relation to the rotor blade comprise a first part 10
configured for contacting the rotor blade at regions at or near the
rear edge of the rotor blade and a second part 8 located
essentially at or near the second end of the frame and configured
for contacting the rotor blade at regions at or near the front edge
of the rotor blade, and wherein said means for lowering and/or
lifting the device in relation to the rotor blade comprise
suspension means, by means of which the frame 2 is suspended in a
triangular configuration, wherein said triangular configuration
comprises two suspension locations in a first zone 150 located at
or near the first end of the frame 2 and a further suspension
location in a second zone 152, which is located along a side of the
frame 2, which is configured to extend along the pressure side 54a
of the rotor blade 54.
Inventors: |
Teichert; Paul; (Sydals,
DK) |
Assignee: |
PP ENERGY APS
Nordborg
DK
|
Family ID: |
41445007 |
Appl. No.: |
13/001149 |
Filed: |
June 18, 2009 |
PCT Filed: |
June 18, 2009 |
PCT NO: |
PCT/DK09/00144 |
371 Date: |
January 27, 2011 |
Current U.S.
Class: |
182/19 ;
182/142 |
Current CPC
Class: |
Y02E 10/72 20130101;
F03D 80/50 20160501 |
Class at
Publication: |
182/19 ;
182/142 |
International
Class: |
E04G 3/32 20060101
E04G003/32; E04G 3/30 20060101 E04G003/30 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 26, 2008 |
DK |
PA 2008 00882 |
Sep 29, 2008 |
DK |
PA 2008 01358 |
Claims
1-54. (canceled)
55. A device for enabling access to a rotor blade of a wind
turbine, said device being adapted for being moved in the
longitudinal direction of the rotor blade, the device comprising: a
frame, means for supporting and guiding the device in relation to
the rotor blade, means for lowering and/or lifting the device in
relation to the rotor blade, wherein said frame comprises a first
end and a second end, wherein said means for supporting and guiding
the device in relation to the rotor blade comprise a first part
configured for contacting the rotor blade at regions at or near the
rear edge of the rotor blade and a second part located essentially
at or near the second end of the frame and configured for
contacting the rotor blade at regions at or near the front edge of
the rotor blade, and wherein said means for lowering and/or lifting
the device in relation to the rotor blade comprise suspension
means, by means of which the frame is suspended in a triangular
configuration, wherein said triangular configuration comprises two
suspension locations in a first zone located at or near the first
end of the frame and a further suspension location in a second
zone, which is located along a side of the frame, which is
configured to extend along the pressure side of the rotor
blade.
56. The device according to claim 55, wherein said further
suspension location, which is located in said second zone, is
located at or near the second end of the frame.
57. The device according to claim 55, wherein hoisting means are
located at said suspension locations.
58. The device according to claim 55, wherein lines, cables or
wires are connected to the frame at said suspension locations.
59. The device according to claim 55, wherein at least one of said
hoisting means or fixing means for said lines, cables or wires are
adapted for being moved along the frame, e.g. within said first
zone and/or said second zone, respectively.
60. The device according to claim 55, wherein at least one of said
hoisting means or fixing means for said lines, cables or wires
comprises means for adjusting or influencing the effective
suspension location, for example in the form of a fixed line
guiding arm, an adjustable line guiding arm, an outrigger or the
like.
61. The device according to claim 55 wherein at least part of the
frame structure comprises a track portion, the track portion being
adapted to guide an, in relation to the track portion, movable
object along the track portion, wherein the device comprises an
object carried by the track, said object comprising a work platform
adapted to carry one or more individuals and/or a tool, a robot, an
apparatus etc. for performing an operation on the rotor blade in a
more or less automated manner.
62. The device according to claim 55, wherein said means for
lifting and/or lowering the device in relation to the rotor blade
comprises hoisting means having power means such as electric
motors, electric, electronic, hydraulic and/or pneumatic means,
said hoisting means being adapted for climbing up and down a cable
or said hoisting means being adapted for accumulating the cable,
e.g. drum hoisting means.
63. The device according to claim 55, further comprising control
means for controlling the lifting and/or lowering means.
64. The device according to claim 55, further comprising measuring
means, e.g. weighing cells, strain gauges, etc. for measuring the
load for the hoisting means or for each of a plurality of hoisting
means.
65. The device according to claim 55, further comprising measuring
means, e.g. encoders, laser measuring means, etc., for measuring or
estimating e.g. the position of the device, the lifting and
lowering distances and/or velocity for each of a plurality of
hoisting means.
66. The device according to claim 62, wherein said device further
comprises means for automatically adjusting said hoisting means,
e.g. automatic leveling means, in order to provide a desired
position, e.g. a horizontal position of the frame structure.
67. Use of a device according to claim 55 for enabling access to a
rotor blade of a wind turbine, whereby the device is placed near
said wind turbine essentially at ground or sea level, the device is
lifted in relation to said wind turbine by means of at least one
line, wire or the like connected to said wind turbine, when the
device has reached a suitable level, the rotor blade is contacted
by support means at an edge of the rotor blade, which support means
are movable in relation to said device, at a higher level contact
to the rotor blade is established by support means at both edges of
the rotor blade, and the device is lifted and/or lowered in
relation to the rotor blade while supported and guided by said
support means at regions at or near the front edge of the rotor
blade and at or near the rear edge of the rotor blade, whereby the
device is lowered and/or lifted in relation to the rotor blade
using suspension means, by means of which the frame is suspended in
a triangular configuration, wherein said triangular configuration
comprises two suspension locations in a first zone located at or
near the first end of the frame and a further suspension location
in a second zone, which is located along a side of the frame, which
is configured to extend along the pressure side of the rotor
blade.
68. The use according to claim 67, whereby further one or more
objects in the form of a work platform, a gondola, a tool, a robot,
an apparatus, etc. is/are attached to a track portion of said
device before lifting said device in relation to the wind
turbine.
69. The use according to claim 67, whereby measurements are made at
the device or at the hoisting means, e.g. by means of encoders,
laser measuring means, etc., in order to determine the position,
the distance lifted or lowered, the velocity, etc., and whereby
comparisons further may be made with e.g. desired parameters and/or
whereby the actual position and/or balance of the device may be
determined.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is entitled to the benefit of and
incorporates by reference essential subject matter disclosed in
International Patent Application No. PCT/DK2009/000144 filed on
Jun. 18, 2009, Danish Patent Application No. PA 2008 00882 filed on
Jun. 26, 2008 and Danish Patent Application No. PA 2008 01358 filed
on Sep. 29, 2008.
FIELD OF THE INVENTION
[0002] The present invention relates to a device for enabling
access to a rotor blade of a wind turbine, which device is adapted
for being moved in the longitudinal direction of the rotor blade,
and wherein the device comprises a frame structure, means for
supporting and guiding the device in relation to the rotor blade,
and means for lowering and/or lifting the device in relation to the
rotor blade.
[0003] The invention further relates to the use of a device for
enabling access to a rotor blade of a wind turbine.
BACKGROUND OF THE INVENTION
[0004] Within the field of wind turbines it is necessary to perform
work on parts that is situated at a considerable height above
ground level (or sea level, when sea wind turbines are concerned)
such as e.g. repair of rotor blades, the surface of these, surface
treatment of rotor blades and the tower etc. Further, it has been
recognized that it is advantageous or even necessary to clean such
parts and in particular the rotor blades in order to maintain good
results as regards the power efficiency. Further, it may be
advantageous to perform other forms of maintenance in order to
achieve good power production results and optimal economic results,
such as e. g. surface treatments, inspection, etc.
[0005] In order to perform such work a number of hoisting
arrangements have been proposed in the prior art.
[0006] A prior art hoisting arrangement is described in German
utility model DE 296 03 278 U. According to this prior art
arrangement the wind turbine is brought to a stop with one rotor
blade pointing straight downwards, where after suspension means are
fastened to each of the two other rotor blades near the hub of the
rotor. A special work platform with a through-going slit at the
bottom is fixed to these suspension means so that the rotor blade
pointing downwards can be inserted into this slit. The work
platform is subsequently being hoisted upwards in a stepwise
manner, while the crew cleans the surface of the rotor blade
manually, e. g. with one person located on each side of the rotor
blade.
[0007] Even with such an arrangement, it is a time-consuming
process to carry out a cleaning of the rotor blades of a windmill,
just as such a known arrangement would probably require the use of
machinery, such as a crane, for fixation of the special suspension
means. Further, the platform itself will have a considerable weight
and size, thereby leading to further costs and use of heavy
machinery for lifting and lowering the platform.
[0008] Even further, the platform is hanging freely from the
suspension means, which means that the platform is influenced by
the wind and may be moved back and forth, e.g. in windy conditions.
Thus, the platform may be a problematic and dangerous working place
and it may be impossible to use the platform at even relatively
modest wind speeds. Also, even though the platform has rollers at
the edge of the slit to lessen damage to the rotor blade, such
damages may nevertheless occur in certain conditions.
[0009] Devices of a corresponding kind are known from DE 199 09 698
AI and DE 43 39 638 AI, which are encumbered with the same
disadvantages as those mentioned above, including that extensive
use must be made of special material such as cranes, for example
mobile cranes, or relatively comprehensive materials which, for
example, are mounted on the turbine tower beforehand. In
particular, these prior art arrangements may also be influenced by
the wind and may be moved back and forth in relation to the rotor
blade, e.g. in windy conditions and when being moved up and down.
Thus, these prior art platforms may be problematic working places,
it may be impossible to use the platforms at even relatively modest
wind speeds, e.g. at relatively high wind turbines, and collisions
with the surface of the rotor blade may occur, for example when the
platforms are being moved up and down.
[0010] The above-mentioned prior art systems are generally not
configured in a manner facilitating user-friendliness and do not
provide the personnel with an optimal safety environment.
[0011] WO 03/048569 A2 describes a method and an apparatus for
treatment of a surface of a rotor blade of a windmill, where the
apparatus is being placed in such a manner that it is movable in
relation to the surface of a rotor blade, and said apparatus is
being caused to move depending on a form of treatment determined by
means for treatment mounted on, in or next to the apparatus. In
this manner, various forms of treatment of a rotor blade may be
carried out such as for instance washing, finishing, sealing
etc.
[0012] Furthermore, WO 2005/064152 A2 describes a device for
enabling access to a structure above ground level by lowering
and/or lifting the device in relation to the structure, the device
comprising a first endless frame structure defining an opening,
wherein at least part of the first endless frame structure forms a
track portion, the track portion being adapted to guide an, in
relation to the track portion, movable object, such as a gondola,
along the track portion.
[0013] Both of these prior art documents, i.e. WO 03/048569 A2 and
WO 2005/064152 A2 relate to devices, where the devices are
transferred to the rotor blade from below the rotor blade tip.
[0014] Still further, WO 2004/092577 A1 describes a method of
servicing the outer components of a wind turbine such as the wind
turbine blades and the tower with a work platform, said method
comprising the steps of: positioning the work platform at the wind
turbine tower and connecting the work platform to an upper part of
the wind turbine with at least one cable. Further the method
comprises the steps of raising the work platform with the cable and
cable winding means to a position of use, and holding the work
platform to the side of the wind turbine tower with holding
means.
[0015] Even further, WO 2007/085265 A1 discloses a device for
enabling access to a structure above ground or sea level, in
particular a rotor blade of a wind turbine, by lowering and/or
lifting the device in relation to the structure. The device
comprises [0016] a frame structure, [0017] means for supporting the
device in relation to said structure, and [0018] means for lowering
and/or lifting the device in relation to the structure. At least
part of the frame structure of this prior art device comprises a
track portion, the track portion being adapted to guide an, in
relation to the track portion, movable object along the track
portion. The means for supporting the device in relation to the
structure are configured for positioning and guiding said device in
relation to the structure, and the means for supporting the device
in relation to said structure are configured for facilitating a
movement of said device essentially in the longitudinal direction
of said structure
SUMMARY OF THE INVENTION
[0019] It is an objective of the invention to provide an improved
device for performing work at a wind turbine, e. g. on a rotor
blade, where the device can be moved up and down a rotor blade,
which is positioned in an essentially vertical position pointing
downwards.
[0020] It is a further objective to provide such a device whereby
improved user-friendliness and safety may be achieved and whereby
access to virtually all parts of e.g. a rotor blade can be
achieved.
[0021] It is also an objective to provide such a device that may be
designed as a relatively light structure and in relatively light
materials while maintaining safety standards and even provide
improvements in safety aspects. With the increasing heights and
sizes of wind turbines, the above-mentioned objectives have become
increasingly more important, since the increase in wind turbine
size requires corresponding service devices with increased sizes,
whereby the need for a relatively uncomplicated and relatively
light service device requiring only a minimum of resources has been
further accentuated.
[0022] Even further, it is an objective of the present invention to
provide such an improved device that may be moved up and down along
the rotor blade in a safe and secure manner, guided by the rotor
blade, and whereby the device is moving in a smooth manner along
the rotor blade.
[0023] Furthermore, it is an objective of the present invention to
provide such an improved device, which is suspended in a manner
providing improved safety and ease of operation, while minimizing
necessary adjustments of suspension arrangement as the device is
lifted and lowered along the rotor blade as well as when it is
hoisted up and down, e.g. along the side of the wind turbine tower
before or after the device is placed on the rotor blade.
[0024] These and other objectives are achieved by the invention as
explained in detail in the following.
[0025] The invention relates to a device for enabling access to a
rotor blade of a wind turbine, said device being adapted for being
moved in the longitudinal direction of the rotor blade, the device
comprising [0026] a frame, [0027] means for supporting and guiding
the device in relation to the rotor blade, [0028] means for
lowering and/or lifting the device in relation to the rotor blade,
wherein said frame comprises [0029] a first end and [0030] a second
end, wherein said means for supporting and guiding the device in
relation to the rotor blade comprise [0031] a first part configured
for contacting the rotor blade at regions at or near the rear edge
of the rotor blade and [0032] a second part located essentially at
or near the second end of the frame and configured for contacting
the rotor blade at regions at or near the front edge of the rotor
blade, and wherein said means for lowering and/or lifting the
device in relation to the rotor blade comprise suspension means, by
means of which the frame is suspended in a triangular
configuration, wherein said triangular configuration comprises two
suspension locations in a first zone located at or near the first
end of the frame and a further suspension location in a second
zone, which is located along a side of the frame, which is
configured to extend along the pressure side of the rotor
blade.
[0033] Hereby, it is achieved that the device, when it is placed on
the rotor blade, supported and guided by the rotor blade, will be
hanging in a well-balanced manner, e.g. due to the fact that the
center of gravity of the device will be lying well within the
triangular suspension arrangement, e.g. within the triangle defined
by three support points.
[0034] Thus, it is also achieved that counterweight arrangements
can be dispensed with, thereby minimizing weight.
[0035] In particular it is noted that such advantages are achieved
when the device is used in connection with a wind turbine, where
the rotor blades have been put into position which is referred to
as the emergency position, e.g. with the rotor blades turned in
such a manner that the rear or trailing edge of the rotor blade is
turned towards the wind turbine tower and the front or leading edge
of the rotor blade is facing away from the wind turbine tower, in
which case the influence by the wind will be minimized. In such
cases the first end of the frame of the device will be situated
near the wind turbine tower, when the rotor blade pointing
downwards is being serviced, and the second end of the frame of the
device will be situated near the front edge of the rotor blade. It
will be understood that the first end of the frame may also be
referred to as the rear end and that the second end of the frame
also may be referred to as the front end. Lines, cables or wires
that are suspending the device in the triangular arrangement, will
according to this arrangement be located where they will not
interfere with the rotor blade, which might otherwise harm the
surface of the rotor blade and interfere with the proper operation
of the device. Furthermore, the device will also be suspended in a
well-balanced manner, with two suspension points placed at the
frame of the device facing the wind turbine tower and with the
further suspension point placed at the side of the frame adjacent
to the pressure side of the rotor blade. The rotor blade will thus
be located within or essentially within the triangle defined by the
suspension points. Further, it is noted that by having the single
further suspension point on the frame near the pressure side of the
rotor blade, the curvature of the rotor blade can be taken into
consideration, i.e. the fact that rotor blades tend to be designed
in such a manner the rotor blade will curve from root to tip, with
the tip being curved away from the axis in the pressure direction.
Since only a single suspension point is used at the pressure side
of the rotor blade, this can be located at the side of the frame
corresponding to the concave side of the rotor blade, i.e. the
pressure side, whereby it can be ensured that the line, cable or
wire connected to this suspension point will not get in contact
with the rotor blade.
[0036] It is further noted that when reference is made to
suspension locations, of which three are located at the frame, it
will be understood that more than one line, cable or wire can be
fixed to each of such a suspension location, e.g. in a parallel
suspension arrangement. Furthermore, it will be understood that two
or more lines, wires, cables, hoisting means, etc. can be connected
to the frame in such manner that they in essence will constitute a
single suspension location, for example two or more lines, wires,
cables, hoisting means, etc. that are connected to the frame with a
relatively short distance, e.g. a short distance in relation to the
length or width of the frame.
[0037] Preferably, said further suspension location, which is
located in said second zone, may be located at or near the second
end of the frame.
[0038] Hereby, an optimal and preferable balance may be
achieved.
[0039] Advantageously, hoisting means may be located at said
suspension locations.
[0040] Advantageously, lines, cables or wires may be connected to
the frame at said suspension locations.
[0041] According to a further advantageous embodiment, at least one
of said hoisting means or fixing means for said lines, cables or
wires may be adapted for being moved along the frame e.g. within
said first zone and/or said second zone, respectively.
[0042] Hereby, it is achieved that one or more of the corners of
the triangular arrangement may be adjusted, if necessary, for
example in order to adjust the position of the frame and/or the
balance of the frame, while still maintaining the basic triangular
suspension arrangement.
[0043] According to a still further advantageous embodiment, at
least one of said hoisting means or fixing means for said lines,
cables or wires comprises means for adjusting or influencing the
effective suspension location, for example in the form of a fixed
line guiding arm, an adjustable line guiding arm, an outrigger or
the like.
[0044] Hereby, it is achieved that a corner of the triangular
arrangement may be placed selectively in relation to the frame
and/or adjusted in relation to the frame.
[0045] According to a further aspect, the invention relates to a
device for enabling access to a rotor blade of a wind turbine,
wherein said means for supporting and guiding the device in
relation to the rotor blade may be configured for being adjusted to
the rotor blade during movement of the device in order to maintain
controllable contact at said regions, and wherein said means for
supporting and guiding the device in relation to the rotor blade
may comprise a plurality of contact means, at least one of which is
adapted for being omnidirectionally movable along the surface of
the rotor blade while said means for supporting and guiding the
device in relation to the rotor blade are being adjusted to the
rotor blade during movement of the device.
[0046] Hereby, it is achieved that by means of the device the user
may be able to reach or access all parts of the surface of a rotor
blade of a wind turbine since the device can be moved up and down
the rotor blade in a secure manner, guided by the rotor blade. The
means for supporting and guiding the device in relation to the
rotor blade are configured for preferably automatically adapting to
the size and shape of the rotor blade, which vary considerably
along the length, thereby facilitating that the rotor blade can be
accessed along virtually the whole length. Furthermore, it is
achieved that the device is supporting against parts of the rotor
blade, which are suited therefore, i.e. regions at or near the
front edge of the rotor blade and at or near the rear edge of the
rotor blade, and the support is maintained at these regions, even
though these regions moves in dependence on the variations of the
size and shape of the rotor blade along its length. This is
achieved due e.g. to the nature of the contact means, including the
omnidirectionally movable characteristic that allows the contact
means to move along e.g. the path of the rotor blade that is
suitable as support for the device, without undue friction and with
ease.
[0047] The device according to the invention that may e.g. carry a
tool device and/or one or more persons, may be located in any
vertical position along a wind turbine rotor blade, preferably
controlled by a person at the device or at ground level, e. g. by
controlling the means for lowering and/or lifting the device in
relation to the structure. Further, the movable object may be
controlled in such a manner that all parts of the rotor blade can
be accessed.
[0048] Thus, a large and heavy platform is avoided, since a person
using the device according to the invention may access virtually
any desired position in relation to the wind turbine rotor blade.
Hereby any necessary work may be performed using a relatively light
construction. Further the safety standard is enhanced since a
person using the device according to the invention may be secured
in a reliable and dependable manner, e.g. secured to a work gondola
by e.g. a safety line, and since such a person need not move around
on a relatively large platform that may e. g. be swerving under the
influence of the wind and may be bouncing against the rotor blade
and/or against the wind turbine tower.
[0049] Furthermore, it is achieved that the device can be
transferred to the rotor blade in a relatively uncomplicated
manner, without using extensive machinery, while still keeping the
device relatively small in relation to the size of the state of the
art wind turbines.
[0050] As specified, said means for supporting the device in
relation to the rotor blade may be adapted for supporting the
device at or near the front edge of the rotor blade and at or near
the rear edge of the rotor blade.
[0051] Hereby, it is achieved that the device can travel along the
rotor blade in a manner, where the surface of the rotor blade is
not subjected to any harmful contact, i.e. since the device is
designed for contacting the said parts of the rotor blade, which
has the necessary rigidity and sturdiness.
[0052] According to a preferable embodiment at least one of said
plurality of contact means may be adapted for contacting the rotor
blade at a plurality of points and/or at adjoining points.
[0053] Hereby, it is achieved that the contact means can move along
the surface of the rotor blade while providing the necessary
support against the surface of the rotor blade since the at least
one contact means is adapted for contacting the rotor blade at a
plurality of positions and/or at adjoining positions. Thus, the
rotor blade will be able to withstand the load transferred to it by
the contact means while it still will be possible for the contact
means to be displaced along the surface with a minimum of
friction.
[0054] According to a preferable embodiment at least one of said
contact means may comprise brush support means for contacting the
rotor blade.
[0055] Hereby, it is achieved that the device may be supported
against the rotor blade in a manner, whereby the load can be spread
over a relatively wide area, e.g. due to the plurality of bristles
used and/or due to a plurality of brushes being connected together
or carried together by a common carrier, and whereby the contact
means may readily move in any direction. Preferably, brush support
means as used in e.g. the conveying field may be used, for example
industrial brushes as supplied by the company August Mink KG,
Germany.
[0056] According to a further preferable embodiment at least one of
said contact means may comprise belt, drums, rollers or similar
support means for contacting the rotor blade.
[0057] Hereby, it is achieved that the device may be supported
against the rotor blade in a manner, whereby the load can be spread
over a relatively wide area.
[0058] According to a still further preferable embodiment said
belt, drums, rollers or similar support means for contacting the
rotor blade may comprise a plurality of parallel belts, chains,
drums, rollers or similar means.
[0059] Hereby, it is achieved that the device may be supported
against the rotor blade in a manner, whereby the load can be spread
over a relatively wide area.
[0060] Preferably, at least one of said contact means may comprise
a plurality of balls, rollers or the like.
[0061] Hereby, it is achieved that the device may be supported
against the rotor blade in a manner, whereby the load can be spread
over a relatively wide area and whereby the contact means may
readily move in any direction.
[0062] Alternatively, at least one of said contact means may
comprise fluid means, e.g. gas, air, for example in the form of
pneumatic or air cushioning means, liquids, etc. for facilitating
contact to the surface of the rotor blade.
[0063] Hereby, it is achieved that the device may be supported
against the rotor blade in a manner, whereby the load can be spread
over a relatively wide area and whereby the contact means may
readily move in any direction, i.e. omnidirectionally.
[0064] According to a particular preferable embodiment, said means
for supporting and guiding the device in relation to the rotor
blade may comprise means such as strain gauges, weighing cells,
etc. for determining contact load at said regions of the rotor
blade, thereby facilitating detection and/or measurement of
unbalance, variations in rotor blade dimension, e.g. width, wind
pressure, etc.
[0065] Hereby it is achieved that the load put onto the surface of
the rotor blade by the individual contact means can be determined
and that the device can be adjusted, e.g. the means for supporting
the contact means, in such a manner that the load is kept below
predetermined limits, that all contact means take a part in the
support, i.e. no un-loaded contact means, and that the load is
distributed evenly or essentially evenly. Thus, a smooth movement
of the device, when it is moved along the rotor blade, is achieved
when the load or pressure of each of the plurality of contact means
are controlled, since the friction correspondingly is controlled.
Thus, abrupt movements, abrupt stops etc. can be avoided, which
furthermore enhances the safety when using the device.
[0066] According to a further particular advantageous embodiment,
said means for supporting and guiding the device in relation to the
rotor blade may comprise means for detecting an edge of the rotor
blade.
[0067] Hereby, it is facilitated in an expedient manner that the
contact made by the contact means are established and maintained
within the above-mentioned regions, since these can be determined
in relation to the edge or edges of the rotor blade.
[0068] Advantageously, said means for detecting an edge of the
rotor blade may comprise measuring or detecting means such as for
example optical sensing means, e.g. laser means, photo cells,
optical scanning means, etc., radiation means such as X-ray means,
sonic detecting means, e.g. ultrasonic means, etc., radar means,
etc.
[0069] Hereby, the edge or edges of the rotor blade can be detected
with a large degree of accuracy and by means of proven components
and systems.
[0070] Advantageously, the device may comprise control means for
controlling said means for supporting and guiding the device in
relation to the rotor blade on the basis of input signals provided
by said means for determining contact load at said regions of the
rotor blade and/or input signals provided by said means for
detecting an edge of the rotor blade.
[0071] Hereby it is achieved that the device can be controlled to
move along the rotor blade in an automated manner, whereby the
contact means are kept within the desired regions and whereby the
means for supporting and guiding the device in relation to the
rotor blade are controlled in such a manner that the load put onto
the rotor blade by the contact means are within predetermined
limits, whereby also a preferable balance is achieved and whereby a
reliable, safe and user-friendly operation of the device is
achieved, e.g. a movement of the device along the rotor blade,
which does not involve jerks, abrupt movements, abrupt stops,
etc.
[0072] Preferably, said frame structure may have an open
configuration or may be adapted for being opened, e.g. by having a
releasable frame part and/or one or more frame parts that are
pivotal.
[0073] Hereby, it is achieved that the device can readily be
transferred to the rotor blade at a convenient place along the
length of the rotor blade in a relatively simple manner instead of
being placed at the rotor blade at the tip of the blade, where the
distance to the tower is relatively large, thereby making such an
operation relatively complex, when the size of currently used wind
turbines is taken into consideration. Furthermore, as regards a
frame structure that is configured for being opened, it is noted
that when such a frame structure is closed again, it may
essentially and functionally be defined as being an endless frame
structure and that the track essentially may extend along such an
endless frame structure, whereby access can be gained in a
360.degree. configuration.
[0074] Preferably, said means for supporting and guiding the device
in relation to the rotor blade may comprise a rear guide and
support arrangement comprising at least one arm for establishing
contact at said regions at or near the rear edge of the rotor
blade.
[0075] Preferably, said rear guide and support arrangement may be
movable in the longitudinal direction of the device.
[0076] Advantageously, said rear guide and support arrangement may
comprise at least two arms for establishing contact at said regions
at or near the rear edge of the rotor blade, wherein said arms may
be pivotable in relation to the frame structure, whereby variations
in the width of the rear edge of the rotor blade can be
accommodated and whereby further position of the frame structure in
relation to the rotor blade is adjustable.
[0077] Preferably, said means for supporting the device in relation
to said rotor blade may comprise a front guide and support
arrangement comprising one or more of said plurality of contact
means, and wherein said front guide and support arrangement may be
movable, e.g. comprising one or two pivotable arms or the like for
facilitating opening and closing of said frame structure.
[0078] According to a further particular advantageous embodiment,
the contact means, e.g. belts or the like, of said front guide and
support arrangement may comprise contact detection means, for
example sensors, switching means, etc., for detecting the contact
established between the contact means and the rotor blade.
[0079] Hereby, it is achieved that it is detected if e.g. the
contact means, which normally supports against the rotor blade on
the front side, is not in contact with the surface of the rotor
blade, which means that the contact means, which supports against
the other side, is taking the full load of the front part of the
frame. This has the undesired effect that the contact pressure may
be undesirable high and furthermore that the frame may abruptly
move to a position where both contact means are supporting again,
which is undesirable for several reasons, one of which being the
work comfort of the person(s) located in the e.g. work platform(s),
since such a abrupt movement will be at least uncomfortable. Since
such an undesirable situation can be detected in accordance with
this embodiment, measures can be taken to correct the situation and
achieve that e.g. both front contact means are in a correct contact
with the rotor blade.
[0080] Preferably, said front guide and support arrangement may be
adapted for being tilted up or down in order to allow said contact
means to adapt to the direction of movement along the front part of
the rotor blade.
[0081] Advantageously, the device may further comprise one or more
fenders on the inside of the frame structure. Preferably, the
fenders are placed to face each other. Hereby, it can be achieved
that any direct contact between the frame and the rotor blade is as
gentle as possible.
[0082] Preferably, the frame or the fenders may comprise means for
determining and or measuring the contact load. Hereby, measures can
be taken to avoid a situation, where the rotor blades become
squeezed or wedged in the frame.
[0083] Preferably, the fenders may have the form/shape of a
cylinder or a roller.
[0084] Hereby, it can be achieved that the front contact means can
be guided to maintain a desired contact with the rotor blade in
spite of the changing width of the rotor blade front, when the
device is moving up or down, which may require that the suspension
arrangement, e.g. the arms of the front guide and support
arrangement are adjusted, for example a small angle up or down.
[0085] Preferably, the device may further comprise means for
supporting the device in relation to a wind turbine tower, where
said means for supporting the device in relation to the wind
turbine tower are configured for displacing the device in relation
to said wind turbine tower, e.g. when the device is transferred to
or removed from the rotor blade of a wind turbine.
[0086] Hereby, the lifting and lowering of the device along the
tower is facilitated and furthermore, the operations performed when
the device is transferred to the rotor blade or returned to the
tower again are facilitated.
[0087] Preferably, said means for supporting the device in relation
to the wind turbine tower may be configured for adjusting the
position, e.g. the angle of the device in relation to the wind
turbine tower.
[0088] Hereby, it is achieved in a relatively simple manner that
the device can be controlled with great accuracy, when for example
it has reached a height where it is desired to contact the rotor
blade. This may be of particular importance when operating in windy
conditions.
[0089] Advantageously, said means for supporting the device in
relation to the wind turbine tower may comprise means for measuring
the support load, for example for each of the tower support arms,
e.g. in order to determine load distribution between two or more
tower support arms or the like.
[0090] Hereby, it can be determined whether for example two tower
support arms carry essentially the same load or if for some reason,
e.g. wind pressure, the influence of the hoisting means, etc., the
load is (undesirably) uneven, whereby corrective control steps can
be taken
[0091] Still further, the device may comprise an object carried by
the track, said object comprising a work platform adapted to carry
one or more individuals and/or a tool, a robot, an apparatus etc.
for performing an operation on the rotor blade in a more or less
automated manner.
[0092] Hereby, the desired flexibility of the device is achieved in
an expedient manner since the object may be moved along the
circumference of the rotor blade, whereby the complete surface of
the rotor blade can be accessed, e.g. via the track that may be
designed in various manners.
[0093] In connection herewith it is noted that such an object, e.g.
a work platform or a gondola, may be carried by the track in such a
manner that the e.g. gondola is hanging down from the track,
whereby a person in the gondola can effectively treat, inspect,
repair etc., the surface of the rotor blade essentially below the
frame structure of the device. Thus, it will be understood that
even the outer part of the rotor blade, e.g. the tip of the rotor
blade can be treated, inspected, repaired, etc. in this manner,
while the device is supported by the rotor blade. However,
according to a further embodiment, the object, e.g. the gondola may
be carried by the track in such a manner that the e.g. gondola is
essentially located above the track and/or the frame structure,
whereby parts of the rotor blade above the frame structure can be
treated, inspected, repaired, etc. Such an embodiment has for
example the advantage that upper parts of the rotor blade, e.g.
even parts close to the hub can be treated.
[0094] Still further the object may comprise two or more work
platforms, gondolas, tools, robots, apparatuses, etc.
[0095] Advantageously, said two or more work platforms, gondolas,
tools, robots, apparatuses, etc. may be independently movable and
one of said two or more work platforms, gondolas, tools, robots,
apparatuses, etc. may be configured as a master unit and the
other(s) may be configured as slave unit(s), and wherein further
said configuration may be reversed, e.g. in case of an emergency
situation, for example if the power should be disconnected to the
master unit, if the person in the master unit should be indisposed,
etc.
[0096] Hereby, it is achieved that e.g. two persons or more may be
working individually, e.g. at each side of the rotor blade, whereby
the device can be utilized in a fully efficient manner.
Furthermore, it is achieved that the primary control of the device
can take place from the master unit, e.g. the control of the height
of the device, the transfer to and from the rotor blade etc., which
evidently can not be controlled by a plurality of persons or
objects in an efficient manner, whereas the control of the position
of the individual platforms along the perimeter of the rotor blade,
the angular position of the work platforms etc. can efficiently be
performed from each of the individual units.
[0097] Advantageously, said two or more work platforms, gondolas,
tools, robots, apparatuses, etc. may be configured for being
connected together to form a single gondola, work platform, tool,
robot, apparatus, etc. Hereby, a flexible design of the device is
achieved, allowing the objects, e.g. work platforms, tools, robots,
apparatuses, etc. to be used in any desired manner and in view of
the actual circumstances.
[0098] Preferably, the object may comprise seating for one or more
individuals.
[0099] Advantageously, the object may comprise control means for
controlling the position of the object in relation to the track
portion and in relation to the rotor blade.
[0100] Hereby, the person or the persons using the device may
control the device and in particular their own position, e. g. work
position in relation to e.g. the surface of a rotor blade, in an
optimal manner. Further, the work platform may comprise control
means for controlling the lifting/lowering and the positioning in
relation to the structure, which control means may be in the form
of a joystick or the like and by means of which any controllable
part may be individually controlled and/or controlled
simultaneously with other parts. Further, it is noted that a
gyroscopic arrangement may be included in the control system.
[0101] Advantageously, the control means for controlling the
position of the object in relation to the track portion and in
relation to the rotor blade may comprise a rotation, e.g.
360.degree., around the axis of the object and a rotation, e.g. of
180.degree., by means of an eccentric suspension in relation to the
track portion.
[0102] Further, the object, e.g. one or more work platforms,
gondolas, tools, robots, apparatuses, etc., may comprise load
detection means, e.g. for each work platform, gondola, tool, robot,
apparatus, etc. which load detection means may provide input for
control and/or safety means.
[0103] In accordance with a further preferable embodiment, said
means for lifting and/or lowering the device in relation to the
rotor blade may comprise hoisting means having power means such as
electric motors, electric, electronic, hydraulic and/or pneumatic
means and said hoisting means may be adapted for climbing up and
down a cable or said hoisting means may be adapted for accumulating
the cable, e.g. drum hoisting means.
[0104] Hereby, the device will be able to lift and/or lower itself
without power assistance from e. g. a hoist located at the wind
turbine tower, at a vehicle or at a vessel. Thus, the device will
be able to operate independently, e. g. without concern for power
assistance from other devices. This further enhances safe operation
since accidents caused by a power failure at a ground vehicle or at
a vessel are prohibited. Particularly when operation at sea is
concerned, e. g. at sea wind turbines, such an independent
configuration is preferable since a support vessel may be unstable,
e. g. subjected to waves, current, wind etc. Thus, an arrangement
at sea where a vessel provides the elevation by e.g. hoist(s)
located on the vessel is prone to accidents and malfunction, and
therefore a device comprising power means as mentioned above is
advantageous not only in general but especially at sea.
[0105] Further, it is noted that even when power supply to such a
device is subjected to failure, e. g. when electric power is cut
off, a device according to the invention will be able to be
manually operated, e. g. to be hoisted to the ground and will in
general present a safe work tool for all involved, in particular
persons occupying the device.
[0106] Advantageously, the device may further comprise control
means for controlling the lifting and/or lowering means.
[0107] Such control means may be controlled from a platform as
explained above or from e.g. ground level, for example when an
automated operation is taking place.
[0108] According to a particular advantageous embodiment, said
means for lifting and/or lowering the device in relation to the
rotor blade may comprise a plurality of hoisting means, wherein one
of said plurality of hoisting means is a master hoisting means and
wherein the other/others of said plurality of hoisting means is/are
controlled in dependence of the master hoisting means.
[0109] Hereby it is achieved that the device can be lifted and
lowered in such a manner that the device is maintained in a desired
state, e.g. horizontally or at a desired angle while being moved up
and down and/or that furthermore the load taken by the individual
hoisting means are within predetermined limits.
[0110] It will be understood, though, that the hoisting means may
also be synchronized in relation to each other.
[0111] According to a further advantageous embodiment, the device
may comprise measuring means, e.g. weighing cells, strain gauges,
etc. for measuring the load for the hoisting means or for each of a
plurality of hoisting means.
[0112] Even further, the device may comprise measuring means, e.g.
encoders, laser measuring means, etc., for measuring or estimating
e.g. the position of the device, the lifting and lowering distances
and/or velocity for each of a plurality of hoisting means.
[0113] Thus, it will be understood that the hoisting means may be
adapted for measuring or calculating the length of the wire, line
or cable in order to determine the actual altitude of the device. A
calibration of these means may take place, when the device is
placed e.g. at ground level.
[0114] According to a still further advantageous embodiment, the
device may further comprise means for automatically adjusting said
hoisting means, e.g. automatic leveling means, in order to provide
a desired position, e.g. a horizontal position of the frame
structure.
[0115] Advantageously, the device may be adapted to assist
individuals and/or facilitate the use of automated equipment such
as robots in performing inspection, work, repair, surface treatment
etc. on a rotor blade of a wind turbine.
[0116] Preferably, said device may comprise a control system for
automatically controlling actuators, hoisting means etc. of the
device on the basis of control input from e.g. gyroscopic
sensor(s), pressure sensor(s), optical sensor(s) such as laser
sensor(s), strain gauge sensor(s), contact sensor(s) and/or other
sensors, detectors and/or measuring means.
[0117] According to an advantageous embodiment the control system
may be configured for limiting the speed, with which the device is
lowered and/or lifted, when the device is within a predetermined
distance from the ground or another base level or within a
predetermined distance from e.g. the nacelle.
[0118] When moving up and down along the wind turbine tower, it is
desirable to move as fast as possible in view of the considerable
distances, e.g. in order to minimise the non-productive time used
for moving up and down. However, in order to enhance the safety of
the persons involved, the speed of the device may preferably be
limited when the device is getting near the ground, e.g. when the
device is within a few meters to the ground in order to avoid a
hazardous collision with the ground, which in most cases will be a
collision between the ground and the gondola(s) and the person(s)
situated in the gondola(s). The distance to the ground may be
determined or calculated by means of the hoisting means, which as
mentioned above may comprise means for measuring or calculating the
length of the wire, line or cable in order to determine the actual
altitude of the device. However, also special measuring means such
as laser distance means located at the device may be used for this
safety related arrangement, whereby the ground level can be
determined or detected with great accuracy.
[0119] According to a further advantageous embodiment, said means
adapted for supporting the device in relation to a rotor blade of a
wind turbine may be displaceable, e.g. in the lateral direction
and/or the longitudinal direction of the device.
[0120] Hereby, the device can readily travel along the length of
the rotor blade, while the support means are automatically adapted
to the actual size and/or shape of the rotor blade. Furthermore,
the transfer of the device from the tower to the blade is
facilitated in this manner.
[0121] Preferably, said front guide and support arrangement may be
movable in the longitudinal direction of the device.
[0122] Hereby, the control of the position of the contact means in
relation to width and/or position of the rotor blade is
facilitated.
[0123] According to a further aspect of the invention, said means
for supporting the device in relation to a nearby structure may be
configured for supporting against said nearby structure at least at
two points in the vertical direction, and wherein means for
supporting the device at least at one of these points are
adjustable in relation to the nearby structure, e.g. the surface of
a wind turbine tower.
[0124] Hereby, it is achieved that the device can be transported
along the surface of the tower, even when the surface comprises
obstacles or the like, for example in form of flanges or the like
or in the form of various equipment such as for example antennas
that are located at the tower.
[0125] Preferably, the frame structure may form an essentially
elongated structure.
[0126] Hereby, the device can efficiently be used for e.g.
servicing a wind turbine rotor blade, since the elongated
configuration provides the possibility of reaching all parts of the
surfaces of the rotor blade, when the device is moved along the
rotor blade. It is noted that even though the frame structure has
been exemplified as having an essentially U-shaped form, various
other forms are possible. It should be mentioned that for example
rectangular, triangular, circular, oval forms etc. may be used as
well. Further, forms having an L-shape, V-shape, etc. may also be
used, and it is noted that forms allowing access to a restricted
part only of the rotor blade, for example only one side of the
rotor blade, are possible and are within the invention as
characterized in the claims.
[0127] Advantageously, the device may be adapted to assist
individuals in performing inspection, work, repair, surface
treatment etc. on a rotor blade of a wind turbine.
[0128] According to a particular advantageous embodiment, said one
or more objects guided by said track portion, e.g. an object in the
form of a work platform, a gondola, a tool, a robot, an apparatus,
etc. may comprise means for adjusting the position in relation to
said track portion, e.g. transverse to the direction of the track
portion.
[0129] Hereby, it is achieved that in instances, where an object
being guided by the track portion is not positioned optimally in
relation to the rotor blade, e.g. at a suitable work distance, the
object can be displaced until it reaches the desired distance. This
may be particularly important, where the track portion has a gap,
for example at an open end of the frame structure of the device,
e.g. at the front edge of the rotor blade. The adjustment or
displacement of the object may be achieved in various manners, for
example by having the object being suspended in an S-shaped
suspension, which can be rotated, whereby the adjustment is
performed in a circular motion. Further the adjustment can be
performed via a linear movement, for example using a linear
actuator, a beam structure or the like
[0130] Expediently, said means for lifting and/or lowering the
device in relation to the rotor blade may be connected to a
plurality of lines, wires or the like.
[0131] Such wires or lines etc. may be connected to any suitable
location on the wind turbine, e.g. the nacelle, the hub, the tower
etc, and they may be permanently fixed. Furthermore, it is noted
that in accordance with the invention, the device can be operated
using three such lines or wires, two connected at or near the rear
of the device and one connected to a point along the length of the
frame structure, preferably at the end of the frame facing away
from the tower, whereby a triangular suspension is achieved. As it
is explained herein, the device may be balanced, e.g. by adjusting
the position of one or both of these connection points, for example
on the basis of measured parameters and/or gyroscopic inputs.
Further, it is noted that by such an arrangement it is achieved
that during the operation of the device, the lines or wires will
not get in contact with the rotor blade.
[0132] According to a further embodiment, the device may further
comprise means for changing the direction of one or more of the
lines or wires, by means of which the device is hoisted, lifted
and/or lowered with, thereby altering the balance of the
device.
[0133] Hereby, a balancing of the device as described above is
facilitated.
[0134] According to a still further aspect of the invention, the
device may further comprise dampening means for performing a
dampening action of the device in relation to said structure, e.g.
a wind turbine rotor blade or tower.
[0135] Since the device may be used and operated at considerable
heights, it is apparent that the structure itself, e.g. the wind
turbine, and the device, for example the frame structure, a work
platform, a gondola etc. will be affected by the environment, e.g.
influenced by the wind, turbulences, etc. In order to counteract
such influences, the device according to any of the embodiments
described herein may be equipped with means for effecting a
dampening of the undesired influences. Such dampening means may be
passive, but preferably or in addition to passive dampening means
active dampening means may be used. Such active dampening means may
be controlled by control means, for example integrated with the
central control means for the device, and the control of the active
dampening means may take place on the basis of input signals from
e.g. sensor means, by means of which for example wind speed,
turbulence, vibrations etc, may be measured. Hereby it is achieved
that the mass of the device including work platform, gondola,
personnel, tools, etc. may be used to dampen the movements of the
structure itself, for example a rotor blade, in such a manner that
even in windy conditions the structure, e.g. a rotor blade, will be
stable and relatively immobile. Hereby, the working conditions
including the safety of the personnel are also improved
considerably.
[0136] Expediently, said dampening means may be passive dampening
means.
[0137] Preferably, said dampening means may be active dampening
means, whereby an enhanced efficiency is achieved.
[0138] Advantageously, said active dampening means are controlled
by control means.
[0139] Advantageously, said active dampening means may be
controlled on the basis of input signals from e.g. sensor means
such as e.g. wind sensors, accelerometers, etc.
[0140] Expediently, said device may comprise a control system for
automatically controlling actuators, hoisting means etc. of the
device on the basis of control input from e.g. gyroscopic
sensor(s), pressure sensor(s), optical sensor(s), strain gauge
sensor(s) and/or other sensors.
[0141] Hereby, at highly automated operation of the device is
achieved and furthermore, an enhanced user friendliness and an
enhanced efficiency is achieved since for example the user need not
to attend to various compensative control operations in order to
counteract changing wind, changing balance as the device is moved
up and down etc., but can concentrate on the work that has to be
performed.
[0142] According to a further advantageous embodiment, said device
may be adapted for being permanently fixed at said structure, e.g.
at a nacelle of said wind turbine, and adapted for being operated
by lowering and transferring the device to a rotor blade.
[0143] Hereby, a practical solution is provided for the wind
turbines that are being built and will be built with considerable
heights and sizes, where the permanent allocation of a device in
accordance with the invention is justified, e.g. when taking into
account the time and resources needed for lifting a device to the
necessary level, e.g. 200-400 meters or more above ground
level.
[0144] Furthermore, the invention relates to a use of a device for
enabling access to a rotor blade of a wind turbine, whereby [0145]
a device is placed near said wind turbine essentially at ground or
sea level, [0146] the device is lifted in relation to said wind
turbine by means of at least one line, wire or the like connected
to said wind turbine, [0147] when the device has reached a suitable
level, the rotor blade is contacted by support means at an edge of
the rotor blade, which support means are movable in relation to
said device, [0148] at a higher level contact to the rotor blade is
established by support means at both edges of the rotor blade, and
[0149] the device is lifted and/or lowered in relation to the rotor
blade while supported and guided by said support means at regions
[0150] at or near the front edge of the rotor blade and [0151] at
or near the rear edge of the rotor blade, [0152] whereby the device
is lowered and/or lifted in relation to the rotor blade using
suspension means, by means of which the frame is suspended in a
triangular configuration, wherein said triangular configuration
comprises two suspension locations in a first zone located at or
near the first end of the frame and a further suspension location
in a second zone, which is located along a side of the frame, which
is configured to extend along the pressure side of the rotor
blade.
[0153] Preferably, said support means may comprise a plurality of
contact means, at least one of which is adapted for being
omnidirectionally movable along the surface of the rotor blade
while said means for supporting and guiding the device in relation
to the rotor blade are being adjusted to the rotor blade during
movement of the device.
[0154] Hereby, it is achieved that access to a rotor blade at a
wind turbine can be effected in an expedient manner using a device
for performing e.g. service operations, when the device is lifted
along the rotor tower and transferred to the rotor blade not at the
tip of the rotor blade, but at a level, where the distance from the
tower to the rotor blade is convenient. Hereby, a number of
advantages are achieved, including reduced costs and resources.
[0155] Preferably, one or more objects in the form of a work
platform, a gondola, a tool, a robot, an apparatus, etc. may
further be attached to a track portion of said device before
lifting said device in relation to the wind turbine.
[0156] Hereby, it is achieved that the device may be made ready for
operation in an expedient manner, for example when the device is
transported to the actual work site on e.g. trailer or a similar
transport means, the frame of the device is connected to the lines
or wires, lifted a suitable distance and the necessary number of
work platforms, gondolas, tools, robots, apparatuses, etc, e.g. one
or two, is/are connected to the track portion, before the device if
lifted upwards. Similar applies when the device is returned to the
ground.
[0157] Expediently, said device may be supported in relation to the
tower of the wind turbine or in relation to cables extending along
the tower while being lifted or lowered, when the device is not
supported and guided by the rotor blade.
[0158] Hereby, it is achieved that the device is lifted and/or
lowered in a stable and controlled manner.
[0159] Advantageously, said step of establishing contact to the
rotor blade at both edges of the rotor blade may be performed at a
level at or near "chord max"-level, and/or at a level where a
minimum distance, e.g. a safe and suitable distance, between the
front edge of the rotor blade and the tower exists.
[0160] Hereby, the transfer of the device can be effected in a
particular simple manner and in a manner whereby the size, weight,
complexity etc. of the device in relation to the size of the wind
turbine is minimized.
[0161] Expediently, the wind turbine may initially be arranged with
a rotor blade essentially vertical and with the rear edge of the
rotor blade near the tower, e.g. placed in the mode, which may be
referred to as the natural emergency mode of the wind turbine.
[0162] Hereby, optimal working conditions are achieved, e.g. with
the edge of the rotor blade facing any possible wind and whereby
the device may expediently contact the edge as soon as possible
when being lifted upwards, whereby increased stability is
achieved.
[0163] According to a further preferable embodiment, the device may
initially be provided on a vehicle such as a trailer, whereafter
the hoisting means of the device may be connected to a plurality of
cables of the like, which are connected to or at the upper part of
the wind turbine, e.g. at or in the nacelle, at the rotor, for
example at the hub, at the nose of the rotor, etc., at the tower,
etc.
[0164] According to a particular preferable embodiment, the device
may initially be connected to the vehicle, e.g. the trailer, by a
controllable winch, by means of which the movement towards the
tower of the wind turbine may be controlled at an initial step.
[0165] According to a further preferable embodiment, the device may
be controlled, e.g. at an initial step, to automatically perform a
leveling procedure, before the device is being lifted up along the
tower of the wind turbine.
[0166] According to a still further preferable embodiment
measurements may be made at the device or at the hoisting means,
e.g. by means of encoders, laser measuring means, etc., in order to
determine the position, the distance lifted or lowered, the
velocity, etc., and whereby comparisons further may be made with
e.g. desired parameters and/or whereby the actual position and/or
balance of the device may be determined.
[0167] According to a particular embodiment one or more objects,
e.g. two or more work platforms, gondolas, tools, robots,
apparatuses, etc. may be moved independently along the track
portion, wherein one of said two or more work platforms, gondolas,
tools, robots, apparatuses, etc. may configured as a master unit
and that the other(s) may be configured as slave unit(s), and
wherein further said configuration can be reversed, e.g. in case of
an emergency situation.
[0168] According to a further embodiment said two or more work
platforms, gondolas, tools, robots, apparatuses, etc. may be
independently movable along the track portion, but that in
dependence on the level of the device, movement of one or more of
said two or more work platforms, gondolas, tools, robots,
apparatuses, etc. may be restricted by said control system, for
example at levels near the tip of the rotor blade, where movement
along the part of the track portion, which is facing the tower of
the rotor blade is prohibited.
BRIEF DESCRIPTION OF THE DRAWINGS
[0169] The invention will be described in detail in the following
with reference to the drawings, in which
[0170] FIG. 1 shows a device according to an embodiment of the
present invention in a perspective view,
[0171] FIGS. 2-5a show the functional features of the device
according to this embodiment in connection with a wind turbine,
[0172] FIGS. 5b-5c show further embodiments of the device in
accordance with the invention,
[0173] FIG. 6a shows the device seen from above,
[0174] FIG. 6b shows correspondingly the device seen from above in
connection with a rotor blade and furthermore the triangular
suspension arrangement according to an embodiment of the
invention,
[0175] FIG. 7 shows the device seen from an end,
[0176] FIG. 8 shows the device seen from a side,
[0177] FIGS. 9a, 9b show an embodiment of a trolley according to a
further aspect of the invention,
[0178] FIG. 10 shows an embodiment of a work platform or gondola
according to a further embodiment,
[0179] FIGS. 11-25 show various contact means and associated
devices for use in connection with embodiments of the invention,
and
[0180] FIGS. 26-45 show a device according to an embodiment of the
invention and the use hereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0181] In FIG. 1 a device 1 according to an embodiment of the
present invention is shown in a perspective view. This device 1
comprises a frame 2, which in general has a lower frame structure
4, e.g. in the form of a beam, a beam structure, a lattice
structure or the like and an upper frame structure 6. The frame 2
according to the present embodiment has a generally U-shaped
structure. The lower frame structure 4 is provided with a track 5
for carrying and guiding at least one gondola 40, work platform or
the like, which will be described in further detail later on.
[0182] At one end of the device 1 a front guide and support
arrangement 8 is located, which serves the purpose of supporting
and guiding the device in relation to the front of a rotor blade as
it will be described in detail below. As shown, the front guide and
support arrangement 8 is provided with front contact means 12, e.g.
in the form of belts, drums, rollers or the like to support against
the rotor blade. As it will be explained below, the front guide and
support arrangement 8 is adapted for being opened in such a manner
that a rotor blade can enter into the open end of the generally
U-shaped structure of the frame 2.
[0183] A rear guide and support arrangement 10 is connected to the
upper frame structure 6 in such a manner that it can be displaced
along the upper frame structure 6 in order to adapt the device 1 to
the size of the rotor blade. The rear guide and support arrangement
10 is provided with two rear contact means 14 for supporting and
guiding the device 1 in relation to the rear part of the rotor
blade, which will be described in further detail later on.
[0184] The device 1 is further provided with a plurality of
hoisting means for lifting and lowering the device in relation to
the wind turbine tower and in relation to the rotor blade. As
generally indicated in FIG. 1 front hoisting means 22 are provided
at one end of the device and rear hoisting means 20 are located at
the other end, e.g. the end facing the tower. These hoisting means,
which may be electrically, electronically, hydraulically or
pneumatically driven, comprise lines or wires (not shown in FIG.
1), which may be connected to fixing points at e.g. the top of the
wind turbine tower, the nacelle, etc. Preferably, three hoisting
means may be used, two rear hoisting means 20 and one front
hoisting means 22. These hoisting means will be described in detail
later on.
[0185] At the end of the device 1, which is intended to face the
tower, a tower support arrangement 16 is located, which in general
serves the purpose of supporting the device against the side of the
wind turbine tower, while the device 1 is being lifted and lowered,
and further it may assist in bringing the device towards the rotor
blade, as it will be explained later on.
[0186] As mentioned above, the lower frame structure 4 is provided
with a track 5 for carrying and guiding at least one gondola 40,
work platform or the like. As shown, the gondola 40 is carried by a
trolley 30, which can move along the track 5. The gondola 40 is
supported in such a manner that the gondola can be located at
preferably any position along the frame 2 and with a desired
position in relation to a rotor blade, to which the device 1 is
supported, as it will be explained later on. As indicated in FIG.
1, two gondolas 40 can be carried by the device 1, each carried by
a trolley 30.
[0187] In order to further clarify the features of the device
according to the invention, the use of the device 1 will be
explained in general with reference to FIGS. 2-5, which illustrate
the device 1 in a schematic manner, e.g. showing the schematically
illustrated frame 2 with a schematically illustrated gondola 40
placed underneath the frame. In FIG. 2 it is shown that the device
1 has been placed at a wind turbine, e.g. near the tower 52. The
rotor blades 54 have been stopped in a position with one of the
blades pointing essentially downward and with the rear edge of the
blade 54 facing the tower 52, e.g. in the position, which is
referred to as the natural emergency mode of the wind turbine, in
which the influence from the wind is mimimized. The wires or lines
56 have been connected to fixing points at the top of the wind
turbine, e.g. at the tower 52, at the nacelle 53 or at the hub, and
the device 1 is being elevated as shown in FIG. 2, i.e. using the
hoisting means 20 and 22. The device may be supported against the
tower 2 during the elevation, e.g. by means of the tower support
arrangement 16, rollers or the like placed on the frame 2 and
possibly on the gondola 40.
[0188] When the device is being elevated, the frame is open in
order to be able to receive the rotor blade, preferably at least
when the device reaches the level of the tip of the rotor blade 54
as shown in FIG. 3, thereby allowing the rotor blade to gradually
enter into the inner space of the frame 2.
[0189] When the device 1 has reached a level, e.g. as shown in FIG.
4, where the frame 2 may be closed around the rotor blade, possibly
after the device 1 has been displaced away from the tower 52 by the
tower support arrangement 16, the front guide and support
arrangement 8 is actuated to move to the closed position, thereby
establishing a closed or essentially endless frame structure. It
will be understood that the rear guide and support arrangement 10
may be moved towards the rear edge of the rotor blade, which is
facing the tower, in order to make contact with the rotor blade and
support the device, preferably at the earliest possible moment. The
front guide and support arrangement 8 will be placed in such a
manner that it will engage the front edge of the rotor blade 54,
possibly after the tower support arrangement 16 has been retracted
again. It will be understood that the rear guide and support
arrangement 10 may be moved correspondingly in the longitudinal
direction of the frame 2, e.g. by moving along the upper frame
structure 6.
[0190] When the frame 2 has been closed and the support
arrangements have been brought into contact with the rotor blade
52, the device 1 may now be lowered and/or lifted along the rotor
blade 54 as shown in FIG. 5a by means of the hoisting means 20 and
22 and the lines, cables or wires 56, and the gondola 40 may be
moved along the track 5 to essentially any position at the rotor
blade. During these operations the device will be supported and
guided only by the rotor blade.
[0191] When the necessary work has been performed on the rotor
blade 4, the device 1 will be brought to the position as shown in
FIG. 4 before the tower support is established again, the frame 2
is opened again, etc. and the device is being lowered
downwards.
[0192] The front guide and support arrangement 8 and the rear guide
and support arrangement 10 serve to position the device in relation
to the rotor blade and in particular they serve to support against
the rotor blade at regions, where the rotor blade has a suitable
sturdiness, strength and robustness, e.g. at regions at or near the
front edge of the rotor blade and at or near the rear edge of the
rotor blade.
[0193] From this simplified explanation of the use of the device 1
it will be understood that the rear guide and support arrangement
10 will have to move in the longitudinal direction of the device in
order to maintain contact to the specific region at the rear edge
of the rotor blade. However, the front guide and support
arrangement may also be configured for being movable in the
longitudinal direction of the device.
[0194] A further important aspect of the invention shall be
explained with reference to FIG. 5b, which corresponds to FIG. 5a,
but where the wind turbine and the device 1 is seen from a position
in front of the wind turbine. Here it is shown that the rotor blade
54 is curved in the longitudinal direction of the rotor blade in
such a manner that the pressure side of the rotor blade, which is
the side to the right in FIG. 5b, in general has a concave form,
whereas the lee side or the low pressure side of the rotor blade,
which is the side to the left in FIG. 5b, in general has a convex
form in the longitudinal direction. As explained above, preferably
three hoisting means are used, each connected to a line, wire or
cable 56, and preferably two of these hoisting means, e.g. 20 as
shown in FIG. 1, are located at or near the rear end of the frame
2, i.e. the first end of the frame, whereby correspondingly two
lines or wires 56 also will be connected here. The third hoisting
means, e.g. 22 as shown in FIG. 1, is located at or near the front
end of the frame 2, i.e. the second end of the frame, and as
indicated in FIG. 5b, the third hoisting means 22 is located in
such a manner that the line or wire 56 connected to this hoisting
means 22 passes on the pressure side of the rotor blade 54 as shown
in FIG. 5b. Thus, the line or wire 56 connected from the top of the
wind turbine to the third hoisting means 22 will not contact the
rotor blade 54, even when the device 1 has been lowered down to the
tip of the rotor blade 54, which would otherwise have been the
case, if this line or wire had been connected to the frame 2 of the
device 1 in such a manner that it should pass on the lee side or
low pressure side of the rotor blade 54, which is apparent from
e.g. FIGS. 5a and 5b.
[0195] A still further aspect of the invention is illustrated in
FIG. 5c, which corresponds to FIG. 5a, but where the wind turbine
has been provided with a connection point 55 at the hub of the
rotor, e.g. at the nose of the rotor as shown in FIG. 5c. The wire
or line 56, which is connected to the hoisting means 22 located at
the front end of the frame 2, may for example be connected to the
wind turbine at this connection point 55. In connection herewith it
is noted that the wires, lines or cables 56 may be connected to any
suitable connection means that are available at or near the top of
the wind turbine, depending on the actual type and design of the
wind turbine.
[0196] The device 1 according to these embodiments will be further
explained with reference to FIGS. 6a, 6b, 7 and 8, which correspond
to FIG. 1, but wherein the device is seen from above, from the end
and from the side, respectively.
[0197] As shown in FIG. 6a, wherein the device 1 is seen from
above, the frame 2 according to this embodiment is substantially
U-shaped, with the front guide and support arrangement 8 placed at
the open end. This front guide and support arrangement 8 comprises
two front support arms 8a and 8b, each one carrying the front
contact means 12. These front support arms 8a and 8b are connected
to each their side of the frame and are pivotable, e.g. with the
front support arm 8a being able to turn approximately 90.degree.
upwards, while the front support arm 8b is able to turn
approximately 90.degree. downwards, or vice versa, whereby the
frame is opened. The front contact means 12 may as shown be in the
form of relatively wide belts or the like that each is carried by
two rollers or the like.
[0198] As also shown in FIG. 6a, a front hoisting means 22 is
placed at the outer end of the frame 2 and two rear hoisting means
20 are placed at the end of the frame 2 facing the tower. These
hoisting means act on wires, cables or the like, which are
connected to e.g. the tower, the nacelle or the hub, and the
hoisting means comprise pulleys or the like for guiding the wires,
cables or the like above the power means, e.g. the motors of the
hoisting means 20 and 22. For two of the hoisting means shown in
FIG. 6 the pulleys are placed essentially above the respective
power means, but for one of the rear hoisting means 20 a line
guiding arm 60 with respective pulleys 61 is arranged as shown,
whereby the respective line or cable effectively supports the
device at a point to the side of the device. Thus, it will be seen
that the three wires, cables or lines operated by the hoisting
means support the device in a triangular arrangement, whereby it is
also assured that the device is hanging in a well-balanced manner,
e.g. due to the fact that the center of gravity is lying well
within the triangle defined by the three support points.
[0199] As also shown in FIG. 6a, the tower support arrangement 16
comprises two tower support arms 70 and 72, each carrying one or
more tower support wheels 74 and 76. The tower support arms 70 and
72 are individually adjustable, whereby e.g. the distance from the
frame 2 of the device 1 and the tower support wheels 74 and 76 can
be adjusted, whereby the device can be pushed away from the tower.
Furthermore, since the tower support arms 70 and 72 are
individually adjustable, the angle of the device 1 in relation to
the tower can be controlled, which may serve e.g. to position the
device in relation to the rotor blade, for example prior to the
transfer of the device to the rotor blade.
[0200] A preferred tower support arrangement (16) comprises two
tower support arms 70 and 72, each carrying at least three tower
support wheels (not shown). The three support wheels are built in a
triangular construction, where the triangular construction can be
rotated both horizontally and vertically. With two triangular
constructions with a sufficient width between the wheels, the
construction will grip around the tower and the friction between
support arrangement and tower will be added.
[0201] As explained in connection with e.g. FIGS. 5a and 5, the
device 1 may preferably be suspended in a triangular configuration,
which also shall be explained with reference to FIG. 6b. This
Figure shows similar to FIG. 6a the device 1 seen from above and
furthermore a rotor blade 54 is shown, to which the device 1 is
supported and guided by the front guide support arrangement 8 and
the rear guide and support arrangement 10. As mentioned in
connection with FIG. 6a two rear hoisting means 20 are located at
the rear end of the frame 2 (the first end of the frame) and a
single front hoisting means 22 is located at the front end of the
frame 2 (the second end of the frame).
[0202] The two rear hoisting means 20 or rather the locations,
where lines or wires 56 are connected to these, for example the end
of the line guiding arm 60, can be located within a first zone 150
as indicated by punctuated lines in FIG. 6b, which first zone is
placed at the rear end of the frame 2, which as mentioned above
will also be referred to as a first end of the frame 2. This first
zone extends essentially transversely to the frame 2 and may extend
to the sides of the frame as also indicated. Further, the first
zone 150 may extend in the longitudinal direction of the frame as
well and in essence two suspension locations are placed within this
zone, e.g. with one on each side of the frame 2, for example on
each side of a line defined by the front and the rear edge of the
rotor blade 54.
[0203] The rotor blade 54 has a pressure side 54a and a lee side 54
b, which sides also are referred to as the high pressure side and
the low pressure side, respectively, which will be apparent to a
skilled person within the wind turbine field. As shown in FIGS. 6a
and 6b, the front hoisting means 22 is placed at the frame 2 at a
location essentially laterally to the pressure side 54a of the
rotor blade 54, which gives the effect described above that the
line or wire connected to the front hoisting means 22 will not
interfere with the surface of the rotor blade when the device is
moved up and down along the rotor blade 54, which as previously
described is designed with a slightly curved shape in the
longitudinal direction. The suspension location, which is also
referred to as the further suspension location and which is defined
by the front hoisting means 22, may be located within a second zone
152, which may extend along the frame 2 as shown in the
longitudinal direction as well as in a lateral direction, for
example in case the front hoisting means 22 may be adjustable along
the frame and/or in case an adjustable line guiding is provided for
the front hoisting means 22.
[0204] As shown, the two zones 150 and 152 may overlap as long as
it is ensured that the three suspension locations thus defined is
located in a triangular configuration.
[0205] FIG. 7 shows the device 1 from the end, i.e. from the end
facing the tower, where the device is shown with two gondolas 40,
each one carried by a trolley 30. The trolleys 30 can move along
the track 5, which may extend along the length of the lower frame
structure, and as shown, the two gondolas may be situated at each
side of the device, but they may also operate at one and the same
side. They may be independently operated, e.g. by the respective
persons situated in the gondolas, but the may also be operated in a
master-slave-configuration.
[0206] The line guiding arm 60 with respective pulleys 61 that was
described in connection with FIG. 6 is also shown in FIG. 7. It
will be understood that the lines or cables are led via a plurality
of pulleys to the power means of the hoisting means 20, from where
the lines or cables are led down to the ground. Since the hoisting
means climbs up and down the lines or cables, the lines or cables
extend down to ground level. Similar applies for the front hoisting
means 22, and the cable or line from this may preferably be led
along the frame to the rear end of the device, where the cable or
line is led down to ground level. Thus, all of these cables or
lines may be hanging from the device at a place, where they will
not get in the way of the e.g. gondolas 30 moving around under the
frame of the device. In this connection it is noted that each
hoisting means 20 and 22 may operate two cables or lines, one being
a security line, cable or wire. Furthermore, it is noted that each
hoisting means 20 and 22 may be equipped with a security device in
the form of an emergency brake, e.g. a security device performing a
braking in case a predetermined speed limit has been exceeded.
[0207] The hoisting means (20, 22) may be equipped with a manual
security system for manual lowering of the device. The device may
furthermore be equipped with further emergency lowering
arrangements, for example, manual emergency hoisting means, placed
in connection with the frame at the first end. In case an emergency
situation occurs, when the device is placed towards the rotor blade
(54) with closed support arms (8a, 8b), the work platforms may be
moved to the rear end of the frame and the persons in the working
platforms may grip a wire or the like from the emergency hoisting
means and manually move the working platform to the front support
arms, connect the wires around the rotor blade and open the front.
The device can now be lowered towards the tower until the tower
support (16) reaches the tower and the device can be hoisted to the
ground.
[0208] FIG. 7 also shows the rear guide and support arrangement 10
having the rear contact means 14, which are carried by rear support
arms 80 that are pivotably, e.g. actuated by actuators 82. At the
pivot locations sensors, e.g. weighing cells (not shown) are placed
for measuring the force transferred to the rotor blade, e.g.
corresponding to the load with which the rotor blade is influenced
by the contact means 14. The measured signals are used for
controlling the device, e.g. the angle of the rear support arms, in
order to e.g. maintain the load within predetermined limits and in
particular to achieve that the device is supported by both rear
contact means 14.
[0209] Furthermore, it is shown in FIG. 7 that the rear guide and
support arrangement 10 may be equipped with sensor means for
detecting the position in relation to the rear edge of the rotor
blade, which sensor means can provide input signals for a control
system in order to adjust the position of the rear guide and
support arrangement 10 in the longitudinal direction of the device
1, e.g. move the rear guide and support arrangement 10 backwards or
forwards along the upper frame structure 6. Such sensor means may
as shown comprise a sensor or a light source 84 placed on a rear
support arm 80, which sensor or a light source 84 in combination
with a corresponding unit placed on the other side of the rear
guide and support arrangement 10 can provide information as regards
the position of the rear edge of the rotor blade. For example, a
light source, e.g. a laser light source, may cooperate with e.g.
three photo-sensors placed horizontally. In case none of the
sensors detects the light or all of the sensors detect light, the
rear guide and support arrangement 10 is not in a position where
the rear contact means 14 are in a position corresponding to the
desired regions of the rotor blade. If one or two sensors detect
light, however, and the other(s) not, the rear guide and support
arrangement 10 is in a desired position. Depending on the
circumstances and the results, the rear guide and support
arrangement 10 can be appropriately adjusted. It will be understood
that two (or more) such arrangements may be placed at the rear
guide and support arrangement 10, e.g. with sensors at each side of
the rear guide and support arrangement 10 and with corresponding
light sources at each of the rear support arms 80.
[0210] It will be understood that similarly a sensor arrangement,
e.g. an optical sensor arrangement can be located at the end of the
frame 2, where the front guide and support arrangement is placed.
Hereby, it is made possible to detect when a rotor blade enters the
frame, i.e. the rear edge of the rotor blade and subsequently it
can be detected when the rotor blade has entered in full, i.e. when
the front edge of the rotor blade is detected, whereafter the front
support arms 8a and 8b can be closed.
[0211] In FIG. 8 the device shown in FIG. 1 is seen from the side.
Thus, the device comprising the lower frame structure 4 with the
track 5 and the upper frame structure 6 is shown. Two gondolas 40
are carried by trolleys 30, which can move along the track 5 as
described above. The upper frame structure 6 carries the rear guide
and support arrangement 10, which can be moved back and forth as
indicated. In addition to the sensor means 84 described above in
connection with FIG. 7, it is here shown that the corresponding
counterpart is located on the opposite side of the rear guide and
support arrangement 10 in the form of a sensor or a light source
86. It will be understood that two such sensor arrangements may
preferably be used, one for each rear support arm 80, whereby a
detection is performed from each side.
[0212] It will be understood that the front contact means 12 as
well as the rear contact means 14 will be connected to their
respective support arms in a manner allowing a movement, e.g. in
order to adapt to the actual angle of the surface of the rotor
blade.
[0213] As it will be understood, the front contact means 12 and the
rear contact means 14 will serve the purpose of supporting the
device against the surface of the rotor blade, also while the
device is moving up and down the rotor blade. Thus, they must be
designed with a surface having a suitable friction characteristic,
e.g. a small friction, whereby the device may expediently be
hoisted up and down a rotor blade without subjecting the surface of
the rotor blade to any harm, stress or undue load. Furthermore, in
particular as regards the rear contact means 14, they will be
required to move in the longitudinal direction of the rotor blade
as well as in the transverse direction. According to a preferable
embodiment of the invention the rear contact means 14 may be in the
form of brushes, e.g. industrial bristles or brushes, which may
transfer load to the rotor blade at a sufficiently large area,
thereby reducing the load pr. area, and which has the advantage
that they may be moved across the surface in any direction, i.e.
omnidirectionally.
[0214] As regards the front contact means 12 belts, drums, rollers
or the like may preferably be used, which have the advantage in
connection with the relatively broad and rounded front edge that
they may move across the surface even though it is not a strict
linear movement and that they can distribute the load over a
relatively large area. Further, it is noted that these belts may be
provided with a row of sensors, e.g. contact sensors, pressure
sensors located behind the belt in order to detect whether or not
contact has been made and/or maintained with the rotor blade.
[0215] The function of the device 1 will now be explained in
further detail. As explained above, when the device is lifted up
along the wind turbine tower, preferably with the tower support
arrangement 16 supporting the device 1 against the tower, the front
guide and support arrangement 8 is being opened, e.g. by turning
the front support arms 8a and 8b, in order to receive the rotor
blade. This may for example take place, when the device is being
hoisted upwards along the tower. Further, the rear guide and
support arrangement 10 has been moved towards the open end of the
frame, and the rear contact means 14 has been moved to an outer
position, whereby the rear edge of the rotor blade is free to enter
the inner space of the frame. When this happens, it will be
detected by means of sensors, for example the above-mentioned
optical sensors placed at the open end of the frame 2 and/or at the
rear guide and support arrangement 10, and the rear contact means
14 will be moved towards the surface of the rotor blade, until they
contact the surface of the rotor blade at a predetermined region
near the edge. As the rotor blade moves into the open frame, as the
device is hoisted further upwards, the rear guide and support
arrangement 10 is moved towards the tower, controlled by the
control system on the basis of sensor inputs, in order to have the
rear contact means 14 bearing against the rotor blade in the
predetermined region near the rear edge.
[0216] The device may be moved towards the rotor blade by the tower
support arrangement 16, e.g. the tower support arms 70 and 72, for
example, when the device is at a suitable height, where the
distance to the rotor blade is convenient, e.g. in view of the
distance to the front edge of the rotor blade and/or the rear edge
of the rotor blade, for example at or near the location usually
referred to as "chord max", and/or where the distance to the front
edge of the rotor blade is at a minimum or at least sufficiently
small. The movement upwards is stopped and the tower support arms
70 and 72 are controlled to push the opened frame closer to the
rotor blade, until the front guide and support arrangement 8 can be
closed again. Hereafter, the tower support arms 70 and 72 may be
retracted, whereby the device 1 now will support against the rotor
blade by means of the front guide and support arrangement 8.
[0217] In this operative mode, the rear guide and support
arrangement 10 will be moved back and forth in the frame in
correspondence with the varying width of the rotor blade as
explained above.
[0218] As also explained above, the tower support arrangement 16
may further be used for controlling the angular position of the
device in relation to the tower, which for example may be used in
windy conditions to "catch" the rotor blade, when the device is
being hoisted up along the wind turbine tower.
[0219] It will be understood that a tower support arrangement 16
comprising more than two wheels may be used, for example in order
to increase stability. Thus, this or these wheel arrangements may
extend along a larger part of the perimeter of the wind turbine
tower.
[0220] FIGS. 9a and 9b show in enlarged views an embodiment of a
trolley 30, seen from the end and in a perspective view,
respectively. At the upper part, means 32 are provided for gripping
the horizontal flanges of the track 5 and/or the lower frame
structure 4. Further, it is shown that a slit 34 is provided for
accommodating a rib underneath the track 5. Power means 37 such as
an electric motor may transfer drive power to the rib and/or to the
flanges of the track 5. Preferably, the trolley 30 may comprise two
parts 30a and 30b (FIG. 9b), which are connected in such a manner
that they may turn in relation to each other, whereby the trolley
30 can cope with the relatively small turn radius of the track and
whereby the trolley 30 can carry the weight of the e.g. gondola 40
with a person and tool, spare parts, etc.
[0221] The trolley 30 comprises a connection tap 36 for
establishing connection with e.g. a gondola 40. The connection tap
36 can be controlled around its own axis and can be controlled to
turn in relation to the trolley 30, since it is connected to the
trolley by means of a horizontal arm 35 (FIG. 9b), which can turn
in relation to the trolley.
[0222] FIG. 10 shows a corresponding gondola 40 or work platform
for use in connection with the device 1, e.g. for being connected
to a trolley 30 located on the track 5. In order to be connected to
the connection tap 36 of the trolley 30, the gondola is provided
with a corresponding connection part 42. The gondola may be formed
as an open cage of aluminum tubes, possibly with fenders for
preventing that the gondola damages the windmill blade being
inspected, serviced or repaired, etc.
[0223] The cage can accommodate one, two or even more individuals.
The gondola comprises a control panel or the like (not shown),
which allows the individual(s) using the gondola to move the
gondola around the wind turbine blade and lift and/or lower the
device together with the gondola relative to the blade. The up and
down movements of the gondola can for example be provided by use of
a joystick. Further facilities such as rooms for repair equipment
etc. can also be provided. Due to the characteristics of the
trolley 30, the gondola 40 is suspended in an eccentric manner,
which as explained above provides the possibility that the position
of the gondola may be adjusted when the suspension is rotated. The
rotation can be controlled for example by a control panel or a
joystick. Such an embodiment is of particular importance, when a
frame is used, where the track does not extend along a full
perimeter of the rotor blade. It will be apparent to a skilled
person that the suspension can be designed in various other manners
than the one shown in FIG. 9. In essence, a horizontal movement of
the gondola 40 is achieved. Furthermore, it will be understood that
an object in general, e.g. a robot, a tool, an apparatus, etc.,
being supported by the device 1 can be operated corresponding to,
what has been explained above for the gondola 40.
[0224] In connection with FIGS. 1, 6, 7 and 8 the front contact
means 12 and the rear contact means 14 have been described in a
general manner, although it has been mentioned that the rear
contact means 14 may preferably comprise brush means, e.g.
industrial brushes, and that the front contact means 12 may
preferably comprise belts or the like. As mentioned, the contact
means are adapted for transferring a load to the rotor blade in
such a manner that the rotor blade is not damaged, that the contact
means can be moved along the surface with only little friction and
that preferably that can move not only linearly, but move in order
to adapt to the requirement that the above-mentioned regions have
to be tracked, i.e. move in an omnidirectional manner. In the
following these contact means and other means for use as contact
means will be described with reference to FIGS. 11-25
[0225] In FIG. 11 a brush contact means 101 is shown in a side
view. As shown, the brush contact means 101 comprises a base part
102 carrying a plurality of bristles 103, as mentioned for example
industrial bristles for e.g. conveying purposes. The brush contact
means 101 has the advantage that the bristles adapt to the surface
of the rotor blade, that the bristles contact the rotor blade at a
large number of positions, that the friction is relatively low,
that the bristles are not oriented and may move in any direction,
i.e. omnidirectionally, and that the bristles in general are gentle
to the surface. The size of the base part 102 and/or the number of
bristles 103 may be designed in view of the load that has to be
transferred.
[0226] In FIG. 12 it is illustrated that a plurality of such brush
contact means 101 may be combined to form a unified contact means
105. The individual brush contact means 101 may be connected to
each other in a rigid manner but preferably they are connected to
each other in at least a resilient and flexible manner.
[0227] In FIG. 13 it is illustrated how a plurality of brush
contact means 101 may be combined to form a contact means 106 that
can adapt to the surface by having a number of carriers 107 and 108
connected pivotably to each other and to the brush contact means
101.
[0228] FIG. 14 illustrates a further contact means 110 in a side
view. This contact means 110 comprises a base part 111 with an
inlet 113 for e.g. compressed air and having an air chamber 112
having outlets (not shown) facing downwards, e.g. a plurality of
holes, slits or the like, or air outlets in any suitable form for
establishing an air cushion towards the surface of the rotor blade,
whereby omnidirectional movement can be achieved.
[0229] Further, liquid contact to the surface of the rotor blade
may also be used for establishing an omnidirectionally movable
contact means.
[0230] As shown in FIG. 15, a plurality of such air cushion contact
means may be combined to form a unified contact means 115 in a
manner corresponding to, what has been explained above in
connection with FIGS. 12 and 13.
[0231] Furthermore, FIGS. 16 and 17 show a further embodiment of a
contact means 120, seen from the side and from the end,
respectively, where a plurality of modular contact means 110 are
combined in a flexible manner. Here, a number of carriers 121, 122
and 123 are connected pivotally to each other and to the brush
contact means 110, e.g. in such a manner that pivotal movement is
obtained in relation to a plurality of axes, including axes that
are perpendicular to each other. Hereby, the contact means may
adapt to the curvature of the surface in two directions.
[0232] As regards the front contact means 12 that in FIGS. 1, 6, 7
and 8 have been illustrated as belt means with the belt direction
being essentially in correspondence with the axis of the rotor
blade, other embodiments will be illustrated in the following with
reference to FIGS. 18-25.
[0233] In FIG. 18 a rotor blade 54 is shown in a schematic manner
is a sectional view together with two also schematically shown
front contact means 130. These comprise each two drums or the like
132 placed with their axes essentially in parallel with the rotor
blade or with only a small angular difference. On these drums or
the like 132 a belt-type element 131 is placed, which may move
around the drums or the like 132, e.g. effecting a movement in the
transverse direction of the rotor blade 54. This arrangement is
also illustrated in a schematic manner in FIG. 19 in a perspective
view of part of the rotor blade and the front contact means 130. As
shown here, the belt-type element 131 may comprise elements 135,
which can cause a movement in the longitudinal direction of the
rotor blade and which will be described in the following.
[0234] FIG. 22 illustrates such a belt-type element 131, where a
pair of flexible elements 137, e.g. chains or the like, carries a
plurality of roller elements 136, each one comprising a number of
rollers 138 as also shown in FIGS. 23 and 25. FIG. 24 shows such a
roller 138 comprising an outer roller carried by bearing means
139.
[0235] An alternative embodiment of such a belt-type element 131 is
illustrated in FIG. 21, where it is shown that the belt-type
element 131 may comprise a plurality of flexible elements 141, for
example wires, chains, etc. that extend around the drums or the
like 132 and each carries a plurality of rollers 142 as also shown
in FIG. 20, where a small part of a flexible element 141 is shown
with two rollers 142. Thus, it will be understood that such an
arrangement will serve to take care of a movement in the
longitudinal direction of the rotor blade due to the rollers 142
and will also serve to take care of a movement in the transverse
direction of the rotor blade because the flexible elements 141 can
be moved in this direction, carried by the drums or the like
132.
[0236] It will be understood that other embodiments, variations,
etc. are possible when designing such contact means and that
combinations hereof are possible as well.
[0237] A device according to an embodiment of the invention and the
use hereof will now be explained in further detail with reference
to FIGS. 26 to 45, wherein the use of a device 1 is exemplified in
connection with a land based wind turbine. It will be understood,
though, that the device may be used in a similar fashion in
connection with sea based wind turbines.
[0238] In FIG. 26 it is shown that the device is transported to the
location of the wind turbine as indicated by the tower 52 by means
of a trailer 140. It will be understood that a truck, a lorry or
another type of vehicle may be used instead. As shown in FIG. 27,
the trailer 140 is opened and the covering 142 is moved towards one
end of the trailer 140, whereby the device 1 will be immediately
available for the necessary preparations, as will be explained in
the following.
[0239] The necessary lines, cables, wires or the like 56, which
have been connected to e.g. the top of the tower 52, is connected
to the respective hoisting means 20 and 22, and as shown in FIG.
29, a line, cable or the like 144 is connected from a winch 146 or
the like, which is placed on the trailer 140, to the device 1. This
line 144 and the winch 146 serves to control the position of the
device 1, while the hoisting means 20 and 22 are controlled to lift
the device 1 slightly, whereby as indicated in FIG. 29, the device
can be brought to a position near the tower 52, where it will be
hanging from the lines, wires or the like 56. Here, the tower
support arrangement may initiate its operation, e.g. by
establishing a support against the tower by means of e.g. the tower
support arms, of which the arm 72 is shown in FIG. 29. It is noted
that the control of the device 1 and the associated elements,
winches, hoisting means etc., may be performed using remote control
devices and/or control devices located at the device and/or at the
trailer or any other suitable place.
[0240] As shown in FIG. 30, the trailer may now be removed, whereby
it will be possible to make the device ready for operation, e.g. by
taking the work platforms 40 down from the storage place and by
connecting the work platforms 40 to the device 1, e.g. to the
trolleys 30, which are mounted on the track 5 of the lower subframe
4 as indicated in FIG. 31. As also shown in FIG. 31, the rear
support arms 80 are moved on the device 1 to a position near the
tower and erected to their operative positions. Further, it is
noted that at a point in time during or after these preparations,
the device may be controlled to perform an automatic leveling, e.g.
based on gyro signals, and a calibration may be performed, whereby
the distance near the ground may be taken as the initial level.
[0241] After the necessary preparations, the work person or persons
may enter the platforms 40 as shown in FIG. 32, connect the
security lines and the movement upwards may start, while the device
1 is supported against the tower 52. During the movement upwards,
the device is controlled as mentioned above, e.g. with one hoisting
means serving as a master and the other as slave units, whereby an
e.g. horizontal position may be maintained. As also shown in FIG.
32, the cables, wires, lines or the like 56 are all led to a
position near the tower 52, from where they are hanging downwards
close together. It is noted that the hoisting means may be of the
type, which are crawling up and down the lines, whereby the lines
always will extend down to the ground. If drum type hoisting means
are used, the lines may be accumulated on e.g. a drum instead.
[0242] As previously explained and as shown in FIG. 33, when a
height is reached, where the rotor blade 54 is within reach, the
front guide and support arrangement 8 has been opened, e.g. with
the front support arm 8b being tilted downwards and the other arm
(not shown in FIG. 33) tilted upwards. Furthermore, the rear guide
and support arrangement 10 has been moved forward, whereby the rear
support arms 80 with the rear contact means 14 are ready to
accommodate the rotor blade 54. By means of the above described
sensor arrangements etc., the position of the rear edge of the
rotor blade 54 in relation to the rear guide and support
arrangement 10 is detected and the rear support arms 80 with the
rear contact means 14 are controlled in dependence hereupon, e.g.
in order for the rear contact means 14 to contact the desired
regions of the rotor blade.
[0243] As the device 1 moves upwards as shown in FIG. 34, the rear
support arms 80 with the rear contact means 14 is moved towards the
tower 52 and the rotor blade enters the inner space of the frame 2.
As also shown in FIG. 34, the tower support arrangement, e.g. the
tower support arm 72, may push the device further towards the rotor
blade 54, until it is detected by a sensor arrangement at the front
guide and support arrangement 8 that the rotor blade 54 is fully
within the frame 2, whereafter the frame can be closed, e.g. the
front support arms 8a and 8b with the front contact means 12 can be
turned back to closed position, whereafter the frame is closed.
[0244] The tower support arrangement may now be retracted,
whereafter the device 1 is supported by the front contact means 12
and the rear contact means 14, while hanging from the lines, wires,
cables or the like 56. As explained previously, when moving up and
down by means of the hoisting means 20 and 22, the front contact
means 12 may be controlled by adjusting the angle of the front
support arms 8a and 8b in order to achieve that the rotor blade is
being supported against both of the front contact means 12,
controlled by e.g. sensors placed along the front contact means 12.
Further, as also explained above, the position of the rear contact
means 14 may be controlled by means of the sensor arrangement at
the rear guide and support arrangement. Further, as also explained
above, the rear support arms 80 may be pivoted away from or towards
the rotor blade 54 in order to achieve a desired (lateral) position
of the device 1 in relation to the rotor blade 54 and/or in order
to achieve an even or an acceptable distribution of the load
exerted by the rear contact means on the rotor blade, based on
input from e.g. strain gauges, weighing cells, etc. Other control
arrangements and associated sensor/detector arrangements have been
described above.
[0245] As shown in FIGS. 35, 36, 37 and 39, the device 1 may now be
moved up and down the rotor blade 52, while the work platforms 40,
carried by the trolleys 30 on the track 5, may be moved to any
desired position, allowing the person(s) to e.g. work on, inspect
etc. any part of the rotor blade 54 on any side of the rotor blade,
even the tip of the rotor blade 54 as shown in FIG. 39. During the
movement, the rear guide and support arrangement 10 is controlled
accordingly.
[0246] It is noted that at the position shown for example in FIG.
39, a work platform 40 may not be allowed to pass along the part of
the track near the tower, since the weight of the work platform and
the person in it may create an undesired unbalance in relation to
the support established to the rotor blade. The control system of
the device 1 may automatically prohibit that a work platform is
moved in such an undesired manner, e.g. by prohibiting certain
movements for certain positions of the rear guide and support
arrangement 10. For example, when as shown in FIG. 39 both
platforms 40 are positioned on the same side of the rotor blade 54,
it may not be possible for one of the work platforms 40 to pass
along the track 5 to the other side, before the device 1 has been
moved upwards to a position, where the rear contact means 14 have
been moved further towards the tower.
[0247] This is also illustrated in FIG. 38, where the device 1 is
shown from above.
[0248] When the work, inspection, etc. has been performed as shown
in FIG. 40, the device 1 is brought to a level, for example the
"chord max"-level or any other suitable level, where it will be
possible for the tower support arrangement, e.g. the tower support
arms 70 and 72, to support against the tower 52, whereafter the
rear contact arms 8a and 8b may be turned e.g. 90.degree. in
different directions, whereby the frame of the device is opened.
The device may now be allowed to be moved downwards and/or the
tower support arrangement is controllably retracted, allowing the
device 1 to come nearer to the tower 52 as shown in FIG. 41. During
this operation the rear guide and support arrangement 10 is
controlled to maintain the desired contact to the above-mentioned
regions of the rotor blade 54, until the rear guide and support
arrangement 10 is at its end position as shown in FIG. 41. Here,
the device will be supported entirely by the tower support
arrangement, until it has reached a position near the ground as
shown in FIG. 42. As mentioned above, the control system of the
device is equipped with a security system, which will limit the
speed of the hoisting means, when a certain level has been reached
in order to avoid a collision with the ground (or any other
object).
[0249] If the other rotor blades are to be inspected, repaired,
etc., the device 1 is kept in the position shown in FIG. 42 (or at
a higher position), until the rotor has been moved sufficiently for
the next rotor blade to be pointing downwards, the rotor is stopped
and blocked, whereafter the device may moved up along the tower 52
again, etc.
[0250] In FIG. 43, it is shown that the device has been stopped
near the ground, where the device is being prepared for being
placed on the trailer 140 again, e.g. by removing the work
platforms 40 and placing these in a transport location as shown in
FIG. 44, by laying the support arms 80 down, etc.
[0251] As shown in FIG. 45, the trailer 140 is moved to a suitable
position, the line, cable or wire 144 is connected to the device 1,
and by combined control of the winch 146 and the hoisting means 20
and 22, the device can be moved to and placed on the trailer 140,
where the lines, cables, wires or the like 56 are removed, etc.,
the trailer covering 142 is closed, etc, wherafter the device can
be transported to another wind turbine for further work.
[0252] Furthermore, it is noted that the functioning of the device
1 has primarily been explained in connection with one or more work
platform, gondolas or the like, where these have been used by one
or more workers and controlled by these. However, it will be
understood that the control can also be performed at e.g. ground
level and that e.g. a person in a master platform may control the
operation of a slave platform or a slave unit that may for example
perform a job in a more or less automated manner. Further, it will
be understood that the device 1 may perform in a automated or
semi-automated manner, for example without any persons situated in
or at the device. Thus, the one or more objects carried by the
device in its track may thus be operative units, designed for
performing a work operation, possibly controlled from ground level
and controlled by a control system, which receives input from e.g.
sensors, vision systems, etc. which will be apparent for a person
skilled within the field of robotics, automation etc.
[0253] Furthermore, it is noted that the device described above in
addition to hoisting means etc. comprise a number of actuators,
motors, etc. and that these may be designed in numerous manners and
in accordance with the practice within the relevant field. Thus,
these may be designed as pneumatically or hydraulically driven
means and further they may be designed as electric/electronically
driven means, which will be apparent to a skilled person.
[0254] Moreover, the control of the device may preferably as
mentioned above take place by remote control and in this respect it
is noted that wireless communication may be used extensively for
the control system, also as regards the transmission of sensor
signals, measured signals, control signals etc, that are being
communicated between the respective units and elements of the
device and units located e.g. at ground level, wind turbine level
etc.
[0255] While the present invention has been illustrated and
described with respect to a particular embodiment thereof, it
should be appreciated by those of ordinary skill in the art that
various modifications to this invention may be made without
departing from the spirit and scope of the present.
* * * * *