U.S. patent application number 13/580362 was filed with the patent office on 2012-12-20 for grinding device for machine based grinding of rotor blades for wind energy systems.
Invention is credited to Peter Josi.
Application Number | 20120322349 13/580362 |
Document ID | / |
Family ID | 44123179 |
Filed Date | 2012-12-20 |
United States Patent
Application |
20120322349 |
Kind Code |
A1 |
Josi; Peter |
December 20, 2012 |
GRINDING DEVICE FOR MACHINE BASED GRINDING OF ROTOR BLADES FOR WIND
ENERGY SYSTEMS
Abstract
Grinding device 1 for machine-based grinding of rotor blades 100
for wind energy systems, comprising at least one industrial robot
30 and a grinding unit 10, 50, 70 that is guided by the industrial
robot 30, wherein the grinding unit 10, 50, 70 comprises a grinding
means, 12, 52 and a cleaning device 20, that cleans the grinding
means 12, 52 at its grinding surface 64, 53.
Inventors: |
Josi; Peter; (Abtsteinach,
DE) |
Family ID: |
44123179 |
Appl. No.: |
13/580362 |
Filed: |
December 2, 2011 |
PCT Filed: |
December 2, 2011 |
PCT NO: |
PCT/EP11/71656 |
371 Date: |
August 21, 2012 |
Current U.S.
Class: |
451/73 |
Current CPC
Class: |
B24B 53/007 20130101;
B25J 11/0065 20130101; B24B 55/06 20130101; B24B 21/16 20130101;
B24B 27/0038 20130101; B24B 27/0061 20130101; B24D 9/02 20130101;
B24B 19/14 20130101 |
Class at
Publication: |
451/73 |
International
Class: |
B24B 19/14 20060101
B24B019/14; B24B 49/10 20060101 B24B049/10; B24B 53/00 20060101
B24B053/00; B24B 21/16 20060101 B24B021/16 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 6, 2010 |
EP |
10193782.9 |
Claims
1. Grinding device (1) for machine-based grinding of rotor blades
(100) for wind energy systems, comprising: a. at least one
industrial robot (30); and b. a grinding unit (10, 50, 70) that is
guided by the industrial robot (30); wherein c. the grinding unit
(10, 50, 70) comprises a grinding means (12, 52) and a cleaning
device (20) that cleans the grinding means (12, 52) at its grinding
surface (64, 53).
2. Grinding device according to claim 1, wherein the cleaning
device (20) cleans the grinding surface (64, 53) of the grinding
means (12, 52) either a. from time to time in a cleaning process;
or b. continuously during the grinding.
3. Grinding device according to claim 1, wherein the cleaning
device (20) cleans the grinding surface (64, 53) by means of: a. a
nozzle (24) for blowing on of pressurized air; and/or b. a device
(26) for the suction of grinding dust; and/or c. a brush (22) for
brushing the grinding surface (64, 53).
4. Grinding device according to claim 1, further comprising a drive
unit (32, 32') for moving the industrial robot (30) in a direction
(L) of the longitudinal axis of a rotor blade (100).
5. Grinding device according to claim 1, wherein the grinding
device (10, 70) comprises a drum grinding unit (10) with a grinding
sleeve (12).
6. Grinding device according to claim 5, wherein the drum grinding
unit (10) comprises: a. a rigid suction drum (15); and b. elastic,
pneumatically extendable clamping elements (17), that are arranged
at the barrel of the suction drum (15), wherein c. the grinding
sleeve (12) is fixed at the suction drum (15) by the application of
pressure onto the clamping elements (17).
7. Grinding device according to claim 6, wherein a. the suction
drum (15) comprises suction openings (16) at the barrel; b.
air-permitting spaces (11) are present between the clamping
elements (17); and c. the grinding sleeve (12) comprises
perforation openings (62) arranged essentially over its entire
surface; so that grinding dust can be sucked from the grinding
surface (64) through the perforation openings (62), the
air-permitting spaces (11) and through the suction openings
(16).
8. Grinding device according to claim 7, wherein the grinding
sleeve (12) comprises an air- and particle-flow-permitting-layer
(13), preferably a fleece-layer (13), through which suction air and
grinding dust can flow transversally behind the grinding surface
(64) from the perforation openings (62) to the air-permitting
spaces (11).
9. Grinding device according to claim 5, wherein the grinding unit
(70) comprises several drum grinding units (10) that each can be
individually brought into contact with the surface (102) of the
rotor blade (100).
10. Grinding device according to claim 9, wherein the grinding unit
(20) can clean one of the drum grinding units (10) that is not in
contact with the surface of the rotor blade (100).
11. Grinding device according to claim 1, wherein the grinding unit
(50) comprises a belt grinding unit (50) with a circulating
grinding belt (52).
12. Grinding device according to claim 11, wherein the grinding
belt (52) is a perforated grinding belt, that comprises perforation
openings arranged essentially over its entire surface in order to
suck dust through the grinding belt (52).
13. Grinding device according to claim 12, further comprising a
dust removal unit (72) with a. a circulating dust belt; or b. a
dust sleeve (74); that can be guided by the industrial robot (30)
at at least one surface (102) of a rotor blade (100) in order to
clean the surface (102) of the rotor blade (100) from dust
mechanically.
14. Grinding device according to claim 1, wherein the industrial
robot (30) comprises pressure sensors at at least one robot arm
(34, 36) or at the head (38), for controlling the contact pressure
of the grinding unit (10, 50, 70) or the dust removal unit (72)
onto the rotor blade (100).
15. Grinding device according to claim 1, wherein the industrial
robot (30) is also used for coating or lacquering the rotor blade
(100).
Description
1. FIELD OF THE INVENTION
[0001] The present invention relates to a grinding device for a
machine based grinding of rotor blades for wind energy systems. By
the use of the grinding device, grinding tasks can be automated
during the manufacturing and during the maintenance of rotor
blades.
2. PRIOR ART
[0002] The use of wind force for the energy generation is seen as
one of the most environmentally compatible forms of winning energy.
Therefore, wind energy systems are used, that comprise a rotor that
drives a generator and that is supported rotatably at a mast. The
loads, that effect on the parts in particular the rotor blades of a
wind energy system is however very high.
[0003] Atmospheric influences, like for instance wind, water, hail,
UV-radiation, erosion- and bending-loads lead to highest
requirements for the material of the rotor blades. The correct
operation and the surface quality are relevant for the effectivity
and economic efficiency of wind energy systems. Thus, rotor blades
comprise a specific coating, wherein its application is very
time-consuming, since as a rule every single layer of the coating
has to be ground.
[0004] The extremely loaded polymer surfaces of rotor blades are
coated by a plurality of layers. The layer systems for the
protection of the surfaces consist of a so called gel coat,
spatling compound, etch protection and cover lacquers. The products
that are used therefore consist as a rule of solvent-free,
two-component polyurethane compounds. After the application of the
single layers, each one has to be ground.
[0005] These grinding tasks are a very human resource-intensive
process, since they are carried out manually by hand grinding
machines. The rotor blades to be ground comprise for instance a
length of up to about 80 m and a surface to be ground of up to
about 300 m.sup.2. According to this, the surface that has to be
manually ground is very large.
[0006] A further reason for the fact that grinding tasks at rotor
blades are still carried out manually by means of hand grinding
machines, for instance by means of eccentric grinders with dust
suctions lies in the fact that the coatings of the rotor blades to
be ground are designed very viscoplastic and thus the grinding
discs clog very fast.
[0007] With one grinding disc only a little surface can be ground
and then this grinding disc has to be exchanged by a new grinding
disc. This can be done very fast by hand for hand grinding
machines. Up to now there are high changing rates so that grinding
robots could not be used economically. With a grinding
disc--instead of a suction device--only about 0.5 m.sup.2-1.5
m.sup.2 of the viscoplastic coating of a rotor blade can be usually
ground. But the surface of a wind energy wing of about 60 m to
about 80 m wing length is 160 m.sup.2 to 300 m.sup.2, so that per
rotor blade and per grinding iteration about 300-600 grinding discs
have to be used. Usually, there are 3-4 grinding iterations per
rotor blade.
[0008] The viscoplastic coatings of the rotor blades are used,
because rotor blades move with speeds of up to 300 km/h and they
are not allowed to be damaged, when for instance hail stones dash
against them. In the documents DE 298 05 833 U1, DE 199 29 386 A
and DE 297 09 342 U1 coating systems for rotor blades are
described.
[0009] The enormous dimensions of rotor blades and the problems
that come up during the grinding of the viscoplastic coating did
not allow an automization of the grinding tasks up to now. The cost
for the grinding tasks may be 30% and more of the manufacturing
costs of a rotor blade.
[0010] Thus, it is the problem of the present invention to solve
the above mentioned problems and to optimize the grinding process
for rotor blades of wind energy systems and to design it more cost
effective.
3. SUMMARY OF THE INVENTION
[0011] The above mentioned problem is solved by a grinding device
for machine-based grinding of rotor blades for wind energy systems
according to patent claim 1.
[0012] In particular the above mentioned problems are solved by a
grinding device for machine-based grinding of rotor blades for wind
energy systems, comprising at least one industrial robot and a
grinding unit that is guided by the industrial robot, wherein the
grinding unit comprises a grinding means and a cleaning device that
cleans the grinding means at its grinding surface.
[0013] By using a grinding unit that comprises a grinding means
that is cleaned at the grinding surface, an industrial robot that
guids a grinding unit can be used in a grinding device in an
advantageous manner. This was not possible for conventional
grinding means, since a use of a robot was uneconomical because of
the fast clogging of the grinding means and the high exchange rates
of the grinding means. Now, the lifetime of the grinding means is
raised 10-100 times by the cleaning device, so that none or only
very few tool exchanges are necessary for the grinding of the
surface of a rotor blade and an industrial robot can be now used
economically for the grinding of rotor blades.
[0014] Preferably, the cleaning device cleans the grinding surface
of the grinding means either from time to time or continuously
during the grinding. The grinding surface can--if necessary--be
cleaned from time to time, for example depending on the degree of
clogging of the grinding surface, by bringing the grinding surface
after a specific grinding time into contact with a cleaning device.
Alternatively, the cleaning device is in contact with a part of the
grinding surface during the grinding and cleans it continuously
during the grinding.
[0015] Preferably, the cleaning device cleans the grinding surface
by means of a nozzle for blowing on of pressurized air and/or a
device for the suchtion of grinding dust and/or a brush for
brushing the grinding surface. These three measures, lead either on
their own or in any combination with each other to the fact that
also the abrasion of viscoplastic coatings is removed nearly
completely from the grinding surface of the grinding means and
cannot adhere there and cannot clog the grinding surface. By the
active cleaning of the cleaning surface, the life time of the
grinding means is increased but also the quality of the grinding
task.
[0016] During the blowing of pressurized air by means of a nozzle,
adhering grinding particles are loosened, these particles are
removed actively from the grinding surface by the suction of
grinding dust and it is possible by means of a brush to remove even
strongly adhering grinding dust on the grinding surface or larger
sticky adhesions safely. Such a grinding device can be used for a
discontinuous as well as for continuous cleaning of the grinding
surface of the grinding means.
[0017] In a preferred embodiment, the grinding device comprises
furthermore a drive unit for moving the industrial robot in the
direction of the longitudinal axis L of a rotor blade. By doing so,
the industrial robot can move along the rotor blade and grind the
entire surface of the rotor blade.
[0018] In a preferred embodiment the grinding unit comprises a
cylinder grinding unit with a grinding sleeve. A grinding sleeve
comprises a comparatively large grinding surface that can be
cleaned in its region that is currently not in contact with the
rotor blade. The cylinder grinding units are furthermore very
compact and can be moved very well with an industrial robot in
order to grind the surface of the rotor blade as desired.
[0019] In a preferred embodiment the cylinder grinding unit
comprises a rigid suction drum and elastic, pneumatically
expandable clamping elements that are arranged at the barrel of the
suction drum wherein the grinding sleeve is fixed to the clamping
elements at the suction drum by the application of pressure. It is
possible by such an arrangement of the drum grinding unit, to fix
the grinding sleeve very simple and fast at the suction drum so
that a tool exchange--that means the exchange of the grinding
sleeve--can be carried out very easy and fast.
[0020] Furthermore the elastic, pneumatically expandable clamping
elements have the advantage that the grinding sleeve can adapt
itself in some degree to the surface of the rotor blade and
compensates smaller inconsistencies of the positioning of the
grinding device.
[0021] Preferably, the suction drum comprises suction openings at
the barrel and air permitting spaces are present between the
clamping elements and the grinding sleeve comprises perforation
openings arranged essentially over its entire surface in order to
be able to suck grinding dust from the grinding surface through the
perforation openings and through the air permitting spaces and
through the suction openings. With such a construction of the drum
grinding unit it is possible on the one hand to carry out the above
mentioned simple pneumatic clamping of the grinding sleeve to a
rigid suction drum and on the other hand to suck grinding dust from
the grinding surface through the clamping elements, the suction
drum and through the grinding sleeve. By doing so, the dust removal
can be carried out from the grinding surface over the entire
surface, whereby a clogging of the grinding surface is furthermore
minimized and a nearly dustless grinding becomes possible.
[0022] In a preferred embodiment, the grinding sleeve comprises an
air- and particle-flow-permitting layer, in particular a fleece
layer, through which suction air and grinding dust are able to flow
transversely behind the grinding surface from the perforation
openings to the air permitting spaces. By the fleece layer, through
which the suction air and the grinding dust can flow transversely
behind the surface, perforation openings can be arranged over the
entire surface of the grinding surface of the grinding sleeve, so
that the way of the grinding dust from its generation at the
grinding surface to the perforation opening at which it is sucked
away is very short. According to this the air- and
particle-flow-permitting layer behind the grinding surface allows a
dust suction over the entire surface and permits a clogging of the
grinding sleeve. Thus, this dust transport is carried out over the
entire surface and independently from the arrangement of the air
permitting spaces that are formed by the elastic, pneumatically
expandable elements.
[0023] Preferably, the grinding unit comprises several drum
grinding units, that each can be individually brought into contact
with the surface of the rotor blade. By such an arrangement, for
instance in form of a drum grinding unit revolver, grinding sleeves
that are presently not in contact with the rotor blade can be
replaced or cleaned without significantly enlarging the overall
grinding time for the rotor blade. It is also possible to use on
the single drum units grinding sleeves with different graining or
dust drums and to use them very fast.
[0024] Preferably, a cleaning unit cleans one of the drum grinding
units which is not in contact with the surface of the rotor
blade.
[0025] In a further preferred embodiment, the grinding unit
comprises a belt grinding unit with a circulating grinding belt. A
circulating grinding belt is only in contact with the rotor blade
with a part of its grinding surface and the part of the circulating
grinding belt that is not in contact with the rotor blade can move
along a cleaning device, which carries out a cleaning of the
grinding surface. According to this, this embodiment is also
appropriate very well for a continuous cleaning of the grinding
surface during the operation.
[0026] Preferably, the grinding belt is a perforated grinding belt
that comprises perforation openings arranged essentially over its
entire surface. The generated grinding dust can be sucked though
this perforation openings on the shortest-possible way behind the
grinding surface so that a clogging of the grinding belt is avoided
and a nearly dustless grinding is possible.
[0027] In a further preferred embodiment, the grinding device
further comprises a dust removing unit with a circulating dust belt
or a dust sleeve that can be guided by the industrial robot along
at least one surface of the rotor blade, in order to remove dust
mechanically from the surface of the rotor blade. By the use of the
device according to the invention it is not only possible to grind
the surface of a rotor blade automatically but it is also possible
to remove dust from the ground surface completely by means of a
circulating dust belt or a dust sleeve. So it is possible to carry
out the application of a further lacquer layer directly afterwards.
In an advantageous manner, therefore the already present grinding
unit can be used as dust removing unit so that herein only a little
additional effort has to be spent. An automized dedusting of the
grinding surface is significantly faster executable than manual
dedusting by means of towels or similar means.
[0028] In a preferred embodiment, the industrial robot comprises
pressure sensors at at least one robot arm or at the head for
controlling the contact pressure of the grinding unit onto the
rotor blade. By means of these pressure sensors it is ensured, that
the robot arm applies the necessary grinding pressure and the
necessary and precisely defined pressure for cleaning the surface
of the rotor blade respectively. Therefore a very homogenous
grinding- and cleaning-result is achieved.
[0029] Preferably, the industrial robot is also used for lacquering
the rotor blades. By doing so the investment costs of the entire
system is reduced to a minimum, wherein in one system lacquering of
a rotor blade as well as the grinding and the dedusting of the
rotor blade respectively is carried out with the same industrial
robot that has only to exchange the necessary tools between the
single process steps. Also such an exchange can be carried out
automatically. According to this the entire coating processes,
including grinding and dedusting of a rotor blade is reduced to a
fraction of time, compared with conventional systems in which it
has to be ground manually and often also to be lacquered manually.
According to this the manufacturing times as well as the
manufacturing costs are reduced by the grinding device according to
the invention.
[0030] Further preferred embodiments of the invention result from
the sub claims.
4. BRIEF DESCRIPTION OF THE FIGURES
[0031] In the following, preferred embodiments of the invention are
described with reference to the accompanying figures. In which
shows:
[0032] FIG. 1: A first preferred embodiment of a grinding device
for machine-based grinding of rotor blades for wind energy systems
in a front view;
[0033] FIG. 2: The grinding device of FIG. 1 in a top view;
[0034] FIG. 3: A drum grinding unit of the grinding device
according to FIG. 1 in a cross sectional view from the side;
[0035] FIG. 4: A detail of a drum grinding device of FIG. 3 in a
cross sectional view from the side;
[0036] FIG. 5: The drum grinding device of FIG. 3 in an cross
sectional view from the from;
[0037] FIG. 6: A second embodiment of a grinding device for machine
based grinding of rotor blades for wind energy systems in a front
view;
[0038] FIG. 7: A grinding device according to FIG. 6 with an
alternative guiding of the industrial robot at a wall in a top
view; and
[0039] FIG. 8: A front view of a further preferred embodiment of a
grinding device for a machine based grinding of rotor blades for
wind energy systems with a belt grinding unit in a front view;
5. DESCRIPTION OF PREFERRED EMBODIMENTS
[0040] In the following preferred embodiments of the invention are
described with reference to the figures. Single features of the
herein described embodiments can be combined with other embodiments
of the invention.
[0041] FIGS. 1 and 2 show a front view and a top view of a grinding
device 1 for machine-based grinding of rotor blades 100. In FIG. 1
an industrial robot 30 is arranged on the right hand side of the
rotor blade 100 at the wall 60 of a building, wherein it is
possible to move the industrial robot 30 in the longitudinal
direction. The industrial robot 30 can move by means of an
undercarriage 32 at the wall 60 along a longitudinal axis L of the
rotor blade 100 at wall tracks 42. The industrial robot 30 is only
shown in a symbolic manner and can be every industrial robot that
is appropriate for the task that is described in the following. As
shown, the industrial robot 30 comprises an undercarriage 32, a
drive motor 40, a first arm 34, that is attached to the
undercarriage 32 in a hinged manner, a second arm 36 that is
attached to the first arm 34 in a hinged manner as well as a head
38, that is attached to the second arm in a hinged manner Depending
on the construction type of the industrial robot 30 further
swiveling- or rotating-axes can be foreseen. All axes of the
industrial robot 30 are driven in a common manner by a motor and
are controlled by means of a NC-control by means of a program.
[0042] At the head 38 of the industrial robot 30 a grinding unit in
form of a drum grinding unit 10 is attached, that can be guided
NC-controlled by the industrial robot 30 along the surface 102 of
the rotor blade 100, in order to grind the surface. By means of the
industrial robot 30 it is thus possible to grind at least one side
of the surface 102 of the rotor blade 100 in a machine-based manner
For the other side of the rotor blade 100 a second industrial robot
30 with a grinding unit 10, 50, 70 can be provided.
[0043] Alternatively, the rotor blade 100 can be also supported
rotatably around its longitudinal axis, so that the side to be
ground can be rotated in the direction of the industrial robot
30.
[0044] The drum grinding unit 10 is shown in the following in the
FIGS. 3, 4 and 5 in detail. FIG. 3 shows a cross section through a
preferred drum grinding unit 10. The drum grinding unit 10
comprises a rigid suction drum 15 that is equipped with suction
openings 16 around its circumference. Elastic and pneumatically
extendable clamping elements 17 are arranged around the barrel of
the rigid drum 15 that consists preferably of a light metal. The
elastic clamping elements 17 consist preferably of a polymer
material and are supported by an inlet for pressurized air 18 with
clamping air. The clamping elements 17 are connected amongst each
other pneumatically via ducts 19, so that they generate between
themselves air permitting spaces 11, through which the dust can be
sucked into the suction drum 15. The clamping elements 17 are
preferably realized in form of shallow torus-shaped rings or as
single pillows that are arbitrarily shaped.
[0045] A grinding means in form of a grinding sleeve 12 is slided
onto to the suction drum 15 with the clamping elements 17 that are
arranged at the barrel and is fixed to the suction drum 15 by an
application of pressure onto the clamping element 17. Herein the
clamping element 17 expand by inducing of clamping air 18 and fix
the grinding sleeve 12 from inside onto the suction drum 15. It is
especially simple by this pneumatic way of fixation to clamp the
grinding sleeve 12 onto the suction drum 15 and to exchange the
grinding sleeve 12 after the expiration of its lifetime. The
grinding sleeve 12 consists preferably of a wide grinding belt 66
that is coated with grinding particles and is made of a tissue that
is glued together to a cylinder-shaped sleeve.
[0046] The drum grinding unit 10 is preferably equipped with a dust
suction device 14 that allows sucking the generated grinding dust
through the grinding sleeve 12 during the grinding. Therefore, the
grinding sleeve 12 preferably comprises over its entire surface
peroration openings 62 that expand at least through the grinding
belt layer 66 so that grinding dust can be sucked from the grinding
surface 64 through the perforation openings 62 and through the
air-permitting spaces 11 between the clamping elements 17 and
through the suction openings 16 into the suction drum 15. From the
suction drum 15 the suction air is sucked together with grinding
particles through a suction air connection 14 into a suction system
(similar to a vacuum cleaner).
[0047] A particular effective dust suction is achieved when the
grinding sleeve 12 comprises in addition on its inner side an air-
and particle-flow-permitting layer 13, in particular a fleece
layer, through which the sucked air and the grinding dust is able
to flow transversally behind the grinding surface 64 from the
perforation openings 62 to the air-permitting spaces 11. This is
exemplarily shown by the arrow 68 in FIG. 4. Thus, the size and the
arrangement of the perforation openings 62 of the grinding sleeve
12 can be chosen according to the generated grinding dust and has
not to be adapted to the arrangement of the air-permitting space 11
between the clamping elements 17. Preferably, the perforation
openings 62 comprise a diameter of about 1 mm-6 mm and are spaced
apart from each other in a distance of about 10 mm-50 mm and are
distributes essentially homogenously over the entire surface of the
grinding sleeve 12. According to this, a nearly complete suction
off of the grinding dust can be carried out so that also for this
reason a clogging of the grinding surface 64 of the grinding sleeve
12 is avoided and only little dust is dispensed to the
environment.
[0048] The drum grinding unit 10 comprises furthermore a drive
motor (not shown) that rotatably drives the suction drum 15 with
the grinding sleeve 12 around its rotation axis in order to grind
the surface 102 by that.
[0049] The industrial robot 30 comprises preferably in its head 38
or in its arms 34, 36 a pressure sensor (not shown) in order to
control the contact pressure of the grinding unit 10 onto the rotor
blade 100.
[0050] As shown in FIG. 5, the drum grinding unit 10 comprises
furthermore a cleaning device 20. The cleaning device 20 comprises
a brush 22 for brushing the grinding surface 64 of the grinding
sleeve 12. Furthermore, the cleaning device 20 comprises a nozzle
24 that can be used for blowing pressurized air onto the surface 64
of the grinding sleeve 12. In addition the cleaning device 20
comprises a surrounding hood 28 that is connected to a suction
element 26, in order to suck grinding dust that was detached by the
brush 22 and the nozzle 24. The suction element 26 can be connected
to the suction element of the suction drum 15.
[0051] The cleaning device 20 detaches in an effective manner at
the grinding surface 64 of the grinding sleeve 12 adhering grinding
dust that cannot be removed by the common suction element. This is
in particular decisive for an effective use of the grinding device
1 according to the invention, since an industrial robot 30 can be
only used in a reasonable manner for grinding of rotor blade 100,
when the life time of the grinding means 12, 52 is so high, that a
significant surface of the rotor blades 100 can be ground without
having to exchange the grinding means 12, 52. By means of the
cleaning device 20 it is possible, also to remove firmly adhering
or sticky grinding dust of viscoplastic coatings of a rotor blade
100 from the grinding surface 64 of a grinding sleeve 12 or the
later described grinding belt 52.
[0052] The FIGS. 6 and 7 show a further embodiment of a grinding
device 1 with an industrial robot 30. In FIG. 6 the industrial
robot is guided via an undercarriage 32 at floor tracks 44 on the
floor 61 of a system in a longitudinally moveable manner FIG. 7
shows an alternative embodiment, wherein the industrial robot 30 is
guided via a undercarriage 32 at wall tracks 42 at the wall 60 of a
building. The grinding device 1 of the FIGS. 5 and 6 differs from
the embodiment according to FIGS. 1 and 2 therein, that at the head
38 of the industrial robot 30 a 4-fold grinding unit 70 is
attached, that comprises three drum grinding units 10 like these of
FIGS. 3-5, as well as one dust removing unit in form of a cleaning
drum 72. The 4-fold grinding unit 70 can--similar to a tool
revolver--be moved around an angle of 90.degree. each so that
either a new drum grinding unit 10 or the cleaning drum 72 can be
used at the rotor blade 100.
[0053] The cleaning drum 72 is similar to the drum grinding unit 10
in its construction, but comprises instead of a grinding sleeve 12,
a cleaning sleeve made of a soft, dust attracting and
air-permitting tissue- or fleece-material. By means of the dust
removing unit in form of a cleaning drum 72 the surface 102 of the
rotor blade 100 can be cleaned mechanically after the grinding
process of remaining dust, so that it can be coated again directly
afterwards.
[0054] In the embodiment that is shown in FIGS. 6 and 7 the
grinding devices 10 and the cleaning drum 72 respectively are not
provided each with an own cleaning device 20, but there is one
common cleaning device 20 for all four units 10, 72. The cleaning
device 20 is fixed to the head 38 at a fixed position, for instance
in the position of FIG. 6. For the discontinuous cleaning, the drum
grinding unit 10 and the cleaning drum 72 each are pivoted to the
cleaning device 20 and is cleaned there. Thus, a cleaning of one of
the drum grinding units 10 and the cleaning drum 72 respectively is
possible when at the same time another unit 10, 72 is in contact
with the rotor blade 100.
[0055] FIG. 8 shows a further embodiment of the grinding device 1
for machine-based grinding of rotor blades 100 for wind energy
systems. In this embodiment of the grinding device 1, the
industrial robot 30 guides a belt grinding unit 50 along the
surface 102 of the rotor blade in order to grind it. The belt
grinding unit 50 comprises a frame 51, at which guide rolls 54 are
rotatably supported, which guide a grinding belt 52 continuously. A
tension roll 56 tightens the grinding belt 52. One of the guide
rolls 54 is preferably driven by an electric motor, in order to
circulate the grinding belt 52. The grinding belt 52 is pressed by
means of pressure elements 58 homogenously onto the surface 102 of
the rotor blade 100 so that a homogenous grinding pressure is
ensured. The pressure elements 58 comprise furthermore a suction
element 59, so that the grinding dust can be sucked directly during
grinding. Therefore the grinding belt 52 is preferably perforated
at its entire surface like the above described grinding sleeve 12,
so that the grinding dust can be removed on the shortest possible
way from the grinding surface 53 and a nearly dust-free grinding
becomes possible. A significant advantage of the belt grinding unit
50 lies in the fact that during the grinding only a part of the
grinding belt 52 is in grinding contact with the surface 102 of the
rotor blade 100. Thus it is possible, to execute a cleaning of the
areas, that are currently not in contact with the surface 102 by
the cleaning device 20. The cleaning device 20 comprises like in
the above described embodiments a nozzle 24 for blowing of
pressurized air onto the grinding surface in order to remove
adhering grinding dust. Furthermore, the cleaning device 20
comprises a brush 22, in order to remove stronger adhering grinding
dust from the grinding surface of the grinding belt 52. The removed
grinding dust is sucked off by a suction element 26. The grinding
device 20 is surrounded by a hood 28, so that no dust can be
dispersed to the environment. By means of the cleaning device 20 it
is possible to clean the grinding belt 52 continuously during the
operation at its grinding surface, so that grinding dust cannot
adhere and it cannot come to a clogging of the grinding belt 52.
This significantly increases the lifetime of the grinding belt 52,
so that it is possible, to grind the complete rotor blade 100 with
only one grinding belt completely.
[0056] Another advantage of the belt grinding unit 50 also compared
to drum grinding units lies in the fact that its grinding
performance is adaptable by a corresponding dimensioning of the
grinding means surface. By the choice of the grinding means surface
that is determined by the length and the width of the grinding belt
52 the grinding performance can be adjusted according to the rotor
blade to be ground so that none or at the most only few exchanges
of the grinding belt 52 are necessary per grinding iteration.
[0057] Like in the above mentioned embodiments, the industrial
robot 30 can be guided by means of a drive unit 32, 32' either at
the wall 60 or also at the floor 61 and can move all in all along
the longitudinal direction L at the rotor blade 100. In FIG. 9 both
alternatives of the drive unit 32 and 32' are shown. Furthermore,
the industrial robot 30 can be equipped at one of its arms 34, 36
or at its head 38 with pressure sensors in order to adjust the
contact pressure of the belt grinding unit 50 onto the surface 102
exactly.
[0058] By means of the above described embodiments it is possible
for the first time to use industrial robots 30 economically for the
grinding of rotor blades 100 of wind energy systems. Preferably,
these industrial robots 30 can also execute further functions like
for instance the dedusting of the rotor blade 100 and the
lacquering and coating of the rotor blade 100 respectively.
[0059] When a belt grinding unit 50 is used for dedusting of the
rotor blades 100 the belt grinding unit 50 can be equipped with a
dust belt instead of the grinding belt 52, wherein the dust belt
consists of an air-permitting tissue- or fleece-material. This is
guided similarly to the grinding belt 52 along the surface 102 of
the rotor blade 100 and picks up there the adhering grinding dust
mechanically and cleans the surface 102 so that it can be lacquered
and coated respectively directly afterwards.
[0060] For this lacquer process the industrial robot 30 that is
used for grinding and dedusting respectively can be also used.
Thus, it is possible to carry out in one single system with the
same industrial robot 30 the entire coating process, which consists
of several lacquer-, grinding- and cleaning-processes. Manual work
like for instance the manual grinding or a manual cleaning is
omitted completely. Thus the manufacturing time for the rotor blade
of wind energy systems and according to this also the manufacturing
costs are reduced. Furthermore, by the cleaning of the grinding
means high savings concerning grinding means are achieved, that
also reduce the manufacturing costs.
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