U.S. patent application number 13/114530 was filed with the patent office on 2011-12-29 for root-end of a wind turbine blade.
Invention is credited to Jens Jorgen Ostergaard Kristensen, Michael Noerlem, Henrik Stiesdal.
Application Number | 20110318186 13/114530 |
Document ID | / |
Family ID | 43016697 |
Filed Date | 2011-12-29 |
United States Patent
Application |
20110318186 |
Kind Code |
A1 |
Kristensen; Jens Jorgen Ostergaard
; et al. |
December 29, 2011 |
Root-End of a Wind Turbine Blade
Abstract
The root-end of a blade of a wind turbine contains at least two
segments. The segments contain a connection mechanism for their
connection to build up the root-end. The segments contain a first
segment section, which is prepared for a connection with fiber
reinforced components of the blade. The segments contain a second
segment section, which is prepared for a connection with a hub of a
wind turbine or which is prepared for a connection with
pitch-components of a wind turbine.
Inventors: |
Kristensen; Jens Jorgen
Ostergaard; (Nibe, DK) ; Noerlem; Michael;
(Svenstrup, DK) ; Stiesdal; Henrik; (Odense C,
DK) |
Family ID: |
43016697 |
Appl. No.: |
13/114530 |
Filed: |
May 24, 2011 |
Current U.S.
Class: |
416/219R |
Current CPC
Class: |
Y02E 10/72 20130101;
F03D 1/0658 20130101; Y02P 70/50 20151101; F05B 2230/50 20130101;
Y02E 10/721 20130101; Y02P 70/523 20151101 |
Class at
Publication: |
416/219.R |
International
Class: |
F01D 5/30 20060101
F01D005/30 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 25, 2010 |
EP |
10167326.7 EP |
Claims
1.-11. (canceled)
12. A root-end of a blade of a wind-turbine, comprising: a
plurality of segments, each of the plurality of segments comprise a
connection mechanism to connect to an adjacent segment of the
plurality of segments in order to form the root-end, a first
segment section, which is prepared for a connection with fiber
reinforced components of the blade, a second segment section, which
is prepared for a connection with a hub of a wind turbine or which
is prepared for a connection with pitch-components of a wind
turbine.
13. The root-end according to claim 12, wherein each of the
plurality of segments is a pre-casted component.
14. The root-end according to claim 12, wherein the connected
segments of segments root-end form a circular-shaped diameter.
15. The root-end according to claim 12, wherein the root-end
comprises six segments.
16. The root-end according to claim 12, wherein the root-end
comprises four segments.
17. The root-end according to claim 12, wherein the root-end
comprises two segments.
18. The root-end according to claim 12, wherein the adjacent
segments are connected by a screw connection.
19. The root-end according to claim 12, wherein the adjacent
segments are connected by a dowel connection.
20. The root-end according to claim 12, wherein each of the
plurality of segments includes a hole used for the connection of
the adjacent segments.
21. The root-end according to claim 12, wherein each of the
plurality of segments contain a plurality of resin channels as an
integral part.
22. The root-end according to claim 12, wherein the first segment
section is shaped like a wedge to achieve a smooth transition zone
between the fiber reinforced components of the blade and the
segment.
23. The root-end according to claim 12, wherein the plurality of
segments of the root-end are positioned on a mould, which is used
to support the segments and other blade components for an applied
VARTM-process to manufacture a wind turbine blade.
24. Root-end according to claim 23, wherein a fiber reinforced
material is arranged and/or placed around the plurality of
segments, thereby making the plurality of segments an integral part
of the blade.
25. A blade of a wind-turbine, comprising: a segmented root-end
according claim 12.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of European Patent Office
application No. 10167326.7 EP filed Jun. 25, 2010, which is
incorporated by reference herein in its entirety.
FIELD OF INVENTION
[0002] The invention relates to a root-end of a blade of a wind
turbine and to a wind-turbine blade, which contains this root
end.
BACKGROUND OF INVENTION
[0003] There are a number of different methods, which are used to
manufacture blades of a wind turbine.
[0004] It is known to wind roving tapes or roving bundles around a
core or mandrel to build up a blade of a wind turbine.
[0005] It is also known to produce a blade by two pre-produced
half-shells, which are connected. The half-shells are bonded
(glued) together along their respective leading and trailing edges.
The half-shells are shaped in a way that a common cavity is built
up by them within the manufactured blade. This cavity inside may be
used to support a beam or the like. The beam may be U-shaped or
I-shaped and is used to connect the half-shells by dedicated
contact surfaces. This blade-production-method results in a heavy
blade due to the needed glue.
[0006] A preferred method to manufacture a blade of a wind turbine
is disclosed by document EP 1 310 351 A1. The blade is manufactured
by help of a closed-mould system. The blade is built up like a
sandwich as described below.
[0007] A first mould is used to support a number of stacked layers.
The layers are put on top of the first mould and on top of each
other to build up the three-dimensional shape of the blade.
[0008] A cavity within the blade may be prepared by the usage of a
balloon, which is filled with air for example. The balloon is
embraced by the layers and thus contributes to the
three-dimensional shape of the blade.
[0009] It is even possible to locate pre-fabricated components
within the blade structure, for example along the leading and/or
the trailing edge for reinforcement-purposes.
[0010] A second mould is connected with the first mould, thus a
closed-mould-system is achieved. The closed-mould system embraces
the whole blade-structure.
[0011] Air is evacuated out of the closed-mould-system, while resin
is injected into the closed-mould-system. The resin cures out and
the blade is nearly completed.
[0012] Now the balloons used may be removed out from the blade,
thus a corresponding cavity remains inside the blade.
[0013] This blade-production procedure is also known as "Vacuum
Assisted Resin Transfer Moulding, VARTM"-process.
[0014] Due to the stacked layers wrinkles may occur between and
within the blade components. They may occur typically if fiber-mats
are arranged on top of each other or if fiber mats are located
adjacent to rigid blade-components.
[0015] Document EP 1 109 657 A1 describes a method to produce
closed composite structures. Fiber reinforced material is placed
around a molding core and within a mould-system. The molding core
is filled with a material for its shaping. After a curing process
the filling material is removed out of the core and the whole
molding core is even removed out from a mould-system.
[0016] It is known that the root-end section of a blade, which is
connected with the hub of the wind turbine directly or via
components of a pitch-system, needs to be very strong to cope with
all forces acting on the blade. The root-end also has to be
designed as a rigid interface of the blade to the hub.
[0017] The root-end of the blade needs to be thick and massive,
thus a lot of layers and composite material needs to be arranged
there.
[0018] The root-end of the blade is typically circular-shaped with
a diameter of one meter up to five meters.
[0019] Due to this dimensions it is very difficult to manufacture
the root-end with a uniform thickness and without wrinkles.
[0020] Additionally it is very difficult to control and handle the
casting process of the root-end. Due to its thickness and due to
the used huge number of layers there the infusion and the
distribution of resin within the root-end are very difficult.
[0021] The thick and massive structure of the root-end will contain
a huge and large concentration of resin. Thus the root-end will
become very hot while the resin cures out. This may result to a
weak structure in this critical blade-area.
SUMMARY OF INVENTION
[0022] It is therefore the aim of the invention to provide an
improved root-end of the blade and to provide an improved blade in
view to the problems, which are addressed above.
[0023] This aim is achieved by the features the independent
claims.
[0024] Preferred embodiments of the invention are object of the
dependent claims.
[0025] According to the invention a root-end of the blade is
provided, while the root-end contains at least two segments.
[0026] The segments are preferably produced separately and are
connected later, when the blade is manufactured.
[0027] The segments are designed, arranged and connected in a way
that they are shaped as an appropriate root-end portion. This
root-end portion is able to cope with all forces, which might act
on a blade, which contains the segmented root-end.
[0028] The root-end segment is a pre-casted component preferably.
It is preferably manufactured by a VARTM-process, which uses a
closed-mould system.
[0029] Preferably the completed root-end shows a circular-shaped
diameter, thus each root-end segment is shaped like an arc of a
circle.
[0030] Preferably the root-end is divided into six segments.
[0031] Adjacent segments are preferably fixed to each other to
build up the completed root-end.
[0032] The fixation may contain a screw coupling or a dowel
connection or the like. A number of holes, which are allocated to
surfaces of the adjacent segments, may be used for the connection
used.
[0033] Preferably each single root-end segment show a number of
integrated resin channels. These channels are used to distribute a
dedicated amount of resin to connect the root-end segment with the
other blade components used. Thus a smaller amount of resin is
needed and placed within the root-end in view to the prior art
described above.
[0034] Preferably each root-end segment contains a first segment
section, which is designed and developed for a connection with the
other blade components used.
[0035] Preferably this first segment is formed like a wedge. Thus a
smooth connection or transition of blade components (like fiber
mats) with the root-end segment is achieved while wrinkles are
avoided within the blade-structure.
[0036] Preferably each root-end segment contains a second segment
section, which is designed and developed for a connection of the
completed root-end with the hub or for a connection of the
completed root-end with pitch-components being located asides the
hub.
[0037] Preferably the segments of the root-end are positioned on a
mould as described in the introduction of this application.
[0038] Fiber reinforced material is placed around the root-end
segments during the lay-up work, thus the root-end segments are an
integrated part of the blade, which needs to be manufactured.
[0039] Thus the segments of the root-end become a fully integrated
part of the blade, especially when the well-known VARTM-process is
applied to the closed-mould system to finish the blade.
[0040] Due to the invention it is very easy to align and to
orientate the segments within the blade-production process
used.
[0041] If a VARTM-process is used tolerances of the closed mould
system might be adjusted and balanced very easily.
[0042] The invention allows to lay-up two half-parts of a blade
separately and in parallel. Each half-part comprises at least one
pre-casted root-end segment. Thus the two half-parts of the blade
are built-up in parallel, resulting in a reduced amount of
working-time needed.
[0043] These two half-parts might be brought together and onto a
first mould as described above, while fixation means and/or
transportation means may be used for the positioning of the two
half-parts of the blade. A second mould is used to get the
closed-mould-system, which embraces or incorporates the whole
blade. Finally the VARTM-process may be applied to the connected
half-parts of the blade to finalize it in the well known "single
shot" casting process.
[0044] It is also possible to manufacture two half parts of the
blades by the VARTM-process, using at least one pre-casted root-end
segment in each of the half parts. Finally the two half-parts of
the blade might be connected by help of glue or the like. Thus the
production process is accelerated in view to the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] The invention is shown in more detail by the help of the
attached figures.
[0046] The figures show preferred configurations only and thus do
not limit the scope of the invention.
[0047] FIG. 1 shows a preferred root-end segment according to the
invention,
[0048] FIG. 2 shows a first mould-configuration to produce a
root-end segment invented, and
[0049] FIG. 3 shows a second mould-configuration to produce another
root-end segment invented.
DETAILED DESCRIPTION OF INVENTION
[0050] FIG. 1 shows a preferred root-end segment S according to the
invention.
[0051] This segment S is shaped and prepared to build up a circular
shaped root-end segment with five other segments.
[0052] If all six root-end segments S are connected the circular
root-end is finalized.
[0053] The segment S shows a number of resin channels RC. The resin
channels RC allow the defined distribution of resin within the
segment S and along its surface.
[0054] These resin channels RC are used to distribute a dedicated
amount of resin to connect the root-end segment S with other blade
components used. Thus a smaller amount of resin is needed and
placed within the root-end in view to the prior art described
above.
[0055] The resin channels enable an easy control of the
resin-infusion when the blade is manufactured by help of a
VARTM-process for example.
[0056] Due to the reduced amount of resin needed the curing
temperature is even asides the root-end, while the blade is
manufactured.
[0057] Preferably the blade is manufactured by a VARTM-process thus
the segment S is placed together with fiber mats and other blade
components onto a mould (not shown here). The fiber mats are placed
to overlap at least a part of the segment S, thus the fiber mats
are used connect the segment S with other blade components.
[0058] The segment S shows a first segment section SSB, which is
designed and developed for a connection of the segment S with the
other blade components--like the fiber mats used.
[0059] Preferably this first segment section SSB is formed like a
wedge. Thus a smooth connection or transition of the fiber mats
with the root-end segment S is achieved. Wrinkles are avoided
within the blade-structure due to this smooth transition.
[0060] This wedge-shape provides a gradually transition zone from
the root-end portion to the rest of the blade structure.
[0061] Preferably the segment S contains a second segment section
SSH. This section SSH is designed and developed for a connection of
the completed blade via its root-end with a wind-turbine hub or for
a connection of the completed blade via its root-end with
pitch-components, which are located asides the hub for example.
[0062] This interface SSH to the hub comprises a number of
circumferential connection holes, which are prepared for a
connection with the flange of the hub for example or with the
flange of a dedicated pitch-component.
[0063] For the fixation of the segment S with other adjacent
segments a number of holes H are prepared within a surface of the
segment S. The holes are part of a bolted connection or of a dowel
connection or the like.
[0064] The segment S shown in FIG. 1 covers a 60.degree. segment of
a circle of a completed root-end-portion, thus six segments S are
needed to build up the whole root-end.
[0065] FIG. 2 shows a first mould-configuration MS180 to produce a
root-end segment as invented.
[0066] The mould-configuration MS180 is designed and used to
produce or manufacture a root-end segment as a pre-casted
component.
[0067] This pre-casted component will cover a 180.degree. segment
of a circle of a completed root-end-portion, thus two segments are
needed to build up a completed root-end.
[0068] The mould-configuration MS180 is preferably used within a
VARTM-process to manufacture the segment. Thus a number of fiber
mates FML is put as layers on top of the mould-configuration MS180.
Thus the mould-configuration MS180 is used as lower first mould,
which supports all needed, segment components (as fiber mats for
example).
[0069] Another appropriate mould is used later to achieve the
closed-mould system for the VARTM-process as described in the
introduction of this application.
[0070] FIG. 3 shows a second mould-configuration MS60 to produce
another root-end segment invented.
[0071] The mould-configuration MS60 is designed and used to produce
or manufacture a root-end segment as a pre-casted component.
[0072] This pre-casted component will cover a 60.degree. segment of
a circle of a completed root-end-portion, thus six segments are
needed to build up a completed root-end.
[0073] The mould-configuration MS60 is preferably used within a
VARTM-process to manufacture the segment. Thus a number of fiber
mates FML is put as layers on top of the mould-configuration MS60.
Thus the mould-configuration MS60 is used as lower first mould,
which supports all needed segment components (as fiber mats for
example).
[0074] Another appropriate mould is used later to achieve the
closed-mould system for the VARTM-process as described in the
introduction of this application.
[0075] It is very easy to lay up the fiber mats FML in this mould
MS60 compared with the mould MS180.
[0076] The lay-out-work in the mould MS60 is less tedious than in
the MS180.
[0077] Within the MS180 it is more difficult to obtain a uniform
thickness and to avoid wrinkles, as the fiber mats FML tend to hang
like curtains. They might not follow exactly the shape of the
inner-mould MS180, thus pockets and resin rich areas in the casted
component may be the result.
[0078] Thus the quality of the segments, which are manufactured by
help of the mould MS60, is improved in view to the segments, which
are manufactured by help of the mould MS180.
[0079] It has to be noted that there is at least one another way to
manufacture segments for the root-end-portion of the blade (not
shown here).
[0080] For example a one-piece root-end may be produced like this:
a fiber is spun around a cylinder or around another shaped surface.
The root-end portion is casted to get a stable root-end-portion.
The root end is cut now into a number of root-end segments (for
example into a number of two, four or six segments). Thus
production time is reduced considerably, while wrinkles are
eliminated by this method.
* * * * *