U.S. patent application number 14/759376 was filed with the patent office on 2015-12-10 for safety device for an operator during the servicing of a hub of a wind turbine.
The applicant listed for this patent is SIEMENS AKTIENGESELLSCHAFT. Invention is credited to Henning Ebbesen, Stephan Breum Steen.
Application Number | 20150354233 14/759376 |
Document ID | / |
Family ID | 48049989 |
Filed Date | 2015-12-10 |
United States Patent
Application |
20150354233 |
Kind Code |
A1 |
Ebbesen; Henning ; et
al. |
December 10, 2015 |
SAFETY DEVICE FOR AN OPERATOR DURING THE SERVICING OF A HUB OF A
WIND TURBINE
Abstract
A safety device, for ensuring the safety of an operator, is
arranged in a rotor, in particular of a wind turbine. The device
has a platform with a number of standing surfaces, at least one of
the standing surfaces being substantially horizontal when the
safety device is used as intended, and also having a securing
system for securing the platform to a hub of the rotor and/or to an
inner face of a rotor housing of the rotor.
Inventors: |
Ebbesen; Henning; (Skjern,
DK) ; Steen; Stephan Breum; (Vejle, DK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SIEMENS AKTIENGESELLSCHAFT |
Munchen |
|
DE |
|
|
Family ID: |
48049989 |
Appl. No.: |
14/759376 |
Filed: |
March 28, 2013 |
PCT Filed: |
March 28, 2013 |
PCT NO: |
PCT/EP2013/056683 |
371 Date: |
July 6, 2015 |
Current U.S.
Class: |
182/222 |
Current CPC
Class: |
Y02E 10/72 20130101;
E04G 3/246 20130101; F03D 1/0691 20130101; Y02E 10/722 20130101;
Y02E 10/721 20130101; F03D 80/50 20160501 |
International
Class: |
E04G 3/24 20060101
E04G003/24 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 10, 2013 |
EP |
13150842.6 |
Claims
1. A safety device for the safety of an operator in a rotor,
comprising a platform having a number of standing surfaces of which
when the safety device is used as intended at least one standing
surface lies substantially horizontal, fixing device for fixing the
platform on a hub of the rotor and/or on an inner side of a rotor
housing of the rotor.
2. The safety device according to claim 1 wherein the safety device
is mounted fixed on the hub of the rotor and/or on the inner side
of the rotor housing.
3. The safety device according to claim 1 wherein the platform is
arranged relative to each two connecting flanges of the rotor
blades on the hub so that a standing surface on a side of the
platform facing the rotor housing lies substantially parallel to an
vertex face of the hub.
4. The safety device according to claim 1 wherein the platform
divides a hollow chamber between the hub and the inner side of the
rotor housing into substantially at least two hollow chamber
regions separated from one another.
5. The safety device according to claim 1 wherein the platform
comprises three platform elements each with at least one standing
surface which form a triangle.
6. The safety device according to claim 5 wherein at least one of
the platform elements has at least one opening as access for an
operator.
7. The safety device according to claim 5 wherein the platform
comprises bridging elements which span the contact points of the
platform elements at the respective inner sides of the platform
elements facing a rotor axis (R).
8. The safety device according to claim 7 wherein the platform
elements stand at their inner sides facing the rotor axis (R) at an
angle (.beta.) of 120.degree. to the inner sides of the respective
adjoining bridging elements which are likewise directed towards the
rotor axis (R).
9. The safety device according to claim 5 wherein the fixing device
comprises strut elements which connect the platform at the contact
points of the platform elements to the inner side of the rotor
housing.
10. The safety device according to claim 9 wherein the strut
elements are fastened in the region of interfaces of segments of
the rotor housing.
11. The safety device according to claim 9, further comprising flat
plates as platform elements and/or bridging elements and/or strut
elements.
12. The safety device according to claim 5 wherein an extension (a)
of the platform elements transversely to the rotor axis (R)
comprises at least 1 m, as well as at most 5 m.
13. A rotor with a safety device according to claim 1.
14. A wind turbine with a safety device according to claim 1.
15. A method for securing an operator with a safety device in a
rotor the method comprising: positioning at least one standing
surface of a platform of the safety device, when the safety device
is used as intended, substantially horizontally wherein the
platform is fixed on a hub of the rotor and/or on an inner side of
a rotor housing of the rotor.
16. The safety device according to claim 1, wherein the safety
device is adapted for a wind turbine.
17. The safety device according to claim 6, wherein at least one of
the platform elements has at least one closing element for closing
the opening.
18. The safety device according to claim 12, wherein the extension
(a) of the platform elements transversely to the rotor axis (R)
comprises at least 1.3 m, as well as at most 4 m.
19. The safety device according to claim 12, wherein the extension
(a) of the platform elements transversely to the rotor axis (R)
comprises at least 1.5 m, as well as at most 3 m.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International
Application No. PCT/EP2013/056683 filed Mar. 28, 2013, and claims
the benefit thereof. The International application claims the
benefit of European Application No. EP13150842 filed Jan. 10, 2013.
All of the applications are incorporated by reference herein in
their entirety.
FIELD OF INVENTION
[0002] The present invention relates to a safety device for
ensuring the safety of an operator for an arrangement in a rotor,
more particularly a wind turbine. It furthermore relates to a
method for ensuring the safety of an operator for an arrangement in
a rotor, more particularly a wind turbine.
BACKGROUND OF INVENTION
[0003] By "rotors" are meant for example the drive propellers of
aircraft, hovercraft and ships as well as also the wind and water
wheels serving for obtaining energy. Wind turbines, more
particularly industrial scale wind turbines, have a nacelle which
is mounted on a tower, as well as a rotor which is mounted on the
nacelle. The rotor represents a movable part of the wind turbine.
It is connected by means of a shaft on the drive train to the
interior of the nacelle in which typically the generator as well as
further electrical and electronic elements are located. Within the
scope of the invention by "rotor" is understood the complete unit
of a hub, rotor blades fastened on the hub, and a rotatable
substantially horizontally lying rotor axis. When the rotor is used
as intended the rotor blades drive the hub and the rotor axis and
thus the generator.
[0004] The rotor of the wind turbine is normally fitted with a
plurality of rotor blades, by way of example two, three or more
rotor blades, which are mounted protruding radially away from the
substantially horizontal centre axis of the rotor. During operation
the rotor blades are often turned continuously in the wind by means
of an adjusting mechanism so that an optimum energy yield can be
obtained from the existing wind. This can be achieved for example
by means of a rotation of the nacelle (yaw drive) and/or by means
of a blade angle adjustment (pitch drive) of the rotor blades.
[0005] The rotor represents a highly complex system in which in
particular numerous movable elements such as the rotor blades and
the corresponding adjusting mechanism are arranged. It is therefore
necessary from time to time to carry out maintenance work and when
required even repairs to the rotor. In particular, the hub of the
rotor, that is a rotatable centre piece on which the rotor blades
are fastened (a hub with a pitch drive is furthermore also termed a
"rotor head", however in the following the term "hub" is used as
the standard form), represents a region in which it is particularly
difficult and risky for the service personnel to operate. By way of
example here bolts which are used to fasten the rotor blades on the
hub have to be regularly checked and/or retightened.
[0006] The said service works are nowadays normally carried out by
a person who is secured by mobile frames and/or safety belts. The
service workers thereby have to climb around at a mostly great drop
height in the region of the open hub (i.e. provided with an access
to the nacelle) in the end region of the rotor. Such procedures are
very risky and furthermore complicated since the service workers
have to be secured in the optimum possible way at all times.
SUMMARY OF INVENTION
[0007] Starting from the problem illustrated here an object of the
invention is to provide the possibility for an improved safety of
an operator for working in the hub region of a rotor. More
particularly importance is to be placed on a simpler possibility
for safety, and/or such safety, which is equipped with a higher
safety standard.
[0008] This is achieved by a safety device and by a method
according to the independent claims.
[0009] According to this a safety device of the type mentioned at
the beginning comprises at least the following elements: a platform
having a plurality of standing surfaces of which when the safety
device is used as intended at least one lies substantially
horizontal, fixing device for fixing the platform on a hub of the
rotor and/or on an inside of a rotor housing of the rotor.
[0010] The invention offers the user an at least temporarily
fixedly installed platform with several surfaces which are
configured and measured so that he can stand on them on two legs.
These surfaces are called "standing surfaces" within the scope of
the invention. According to the invention in at least one position
of the rotor one standing surface of the platform lies
substantially horizontal. This position of the rotor is
characterised as being specific for the use of the safety device. A
horizontal surface offers the advantage that it minimizes the
danger of the user slipping off.
[0011] Within the scope of the invention the term "rotor housing"
is to mean the entirety of all the housing segments of the rotor
which surround the hub and connecting flanges of rotor blades on
the hub. The rotor housing comprises in particular also a nose or
cap, i.e. a hood-like cover of the hub against the wind
direction.
[0012] In order to configure the platform so that an operator can
work safely thereon, it is fixed on the hub and/or on the inside of
the rotor housing of the rotor by means of the fixing device. Thus
in the installed state inside the rotor the platform is a part of
the outermost end of the rotor.
[0013] A platform of this kind can be attached fixedly or
detachably in the region of the hub of the rotor by means of the
fixing device. With a solid fixing the platform is in the end a
fixed constituent part of the rotor or hub. In the case of a
detachable fixing the platform or the safety device can also be
formed as an add-on solution or as a mountable and in turn
demountable device. The fixing device can comprise by way of
example a screw, rivet, bolt or adhesive connection.
[0014] By means of the platform which is fixed by the fixing device
in the region of the hub of the rotor, in addition to a usually
curved surface of the hub a number of standing surfaces are
produced which provide the operator at any time with defined paths
and handling regions during the intended use. The maintenance
personnel are furthermore clearly better protected against a fall
from a great height and can operate freely on the platform, more
particularly unimpeded by security harnesses or corresponding
security ropes. Drop paths are shortened since the platform also
functions at the same time as a type of room divider of the
interior space between the hub and the rotor housing. Overall
maintenance and repair works are thereby easier in the region of
the hub of the rotor, by way of example to renew a seal or to
inspect and tighten bolts which fasten the rotor blades on the
hub.
[0015] The invention furthermore comprises a rotor, more
particularly a rotor of a wind turbine having a safety device
according to the invention as well as a wind turbine having a
safety device according to the invention.
[0016] The invention furthermore comprises a method of the type
mentioned at the beginning wherein at least one standing surface of
a platform of the safety device when the safety device is used as
intended is positioned substantially horizontal wherein the
platform is fixed on a hub of the rotor and/or on an inner side of
a rotor housing of the rotor.
[0017] The method according to the invention can be achieved by
means of the safety device according to the invention.
[0018] Further particularly advantageous configurations and
developments of the invention are apparent from the dependent
claims as well as from the following description wherein the
independent claims of one claim category can also be developed
analogously to the dependent claims of another claim category.
[0019] The platform can fundamentally be suspended or mounted
floating on the hub or on the rotor housing so that it is aligned
each time in the properly designated position for use. In this case
at least one standing surface of the platform thus always stands
horizontal. The platform can have by way of example a weight which
draws it always into the horizontal position and an additional
locking device so that it reliably remains in this position during
maintenance work. According to a configuration the safety device is
mounted fixed on the hub of the rotor and/or on the inside of the
rotor housing. The platform thus automatically turns during a
rotational movement of the rotor or hub and the rotor housing, i.e.
in the right direction and angle. More advantageously standing
surfaces of the platform are arranged at different angles to one
another so that the safety device provides a horizontal standing
surface not only in the case of one single position of the
rotor.
[0020] According to an embodiment of the invention the platform is
arranged relative to each two connecting flanges of rotor blades on
the hub so that a standing surface on one side of the platform
facing the rotor housing lies substantially parallel to a vertex
face of the hub. By "vertex face" is meant a region of the curved
surface of the hub which lies between two adjoining connecting
flanges of the hub. With a rotation of the hub about the rotor axis
the vertex faces arranged radially around the rotor axis are
therefore aligned substantially horizontal alternately on a top
side and an underneath side of the hub. "Substantially horizontal"
hereby means that the curved vertex face stands symmetrical
relative to a substantially flat standing surface. A three-vane
rotor has by way of example three vertex faces.
[0021] The maintenance worker normally stands for a particularly
long time on the vertex faces of the hub for example since in the
event of a substantially horizontal alignment these faces represent
a safe, because comparatively less precipitous, standing site and
offer a comfortable access to the adjoining connecting flanges of
the rotor blades. A substantially parallel position of the standing
surfaces on the outsides of the platform relative to the respective
corresponding vertex faces of the hub has proved particularly
favourable since it clearly becomes easier for the operator to
climb from one standing surface to the next vertex face. This then
plays a role particularly when the operator sets up for example a
mobile ladder on the standing surface and where applicable leans
against an end face of the hub and then climbs up the ladder in the
direction of the vertex face.
[0022] The platform of the safety device is advantageously arranged
relative to the main extension directions of the rotor blades of a
wind turbine so that a standing surface always lies substantially
horizontal on an outer side of the platform when a rotor blade
points downwards along a tower of a wind turbine towards a ground
surface. This provides the possibility that a rotor blade mobile
maintenance unit can be moved along the rotor blade between the hub
and a rotor blade tip (for example for inspection and maintenance
work) and at the same time an operator can carry out inspection
and/or maintenance work inside the maintenance chamber between the
hub and the rotor housing.
[0023] The safety device is particularly configured so that the
platform divides a hollow chamber between the hub and the inside of
the rotor housing into essentially at least two hollow chamber
regions separated from one another. The rotor housing can stand at
such a distance from the hub which is measured so that an operator
can move by crawling, kneeling or semi-upright therein. The hollow
chamber can be formed like a dish and is penetrated by at least
three rotor blades which are fitted on the hub. The platform can
extend between a surface on the outside of the hub and a surface on
the inside of the rotor housing. Dividing up the hollow chamber has
proved advantageous since the drop path of an operator when falling
down or sliding down in the hollow chamber along the surface of the
hub is significantly reduced. It is particularly advantageous if
the platform is therefore designed so that it divides the hollow
chamber into a plurality of separated hollow chamber regions.
[0024] Basically the platform of the safety device can have any
shape, for example a polygonal or circular configuration. According
to another embodiment the platform comprises three platform
elements each with at least one standing surface to form a
triangle. The platform elements can be formed circular or angular,
e.g. rectangular or square. They can have the form of a frame, grid
or scaffold, and be of the same or different size. The platform
elements can form a triangle where they are connected to one
another at the ends or at the edges running substantially parallel
to the rotor axis. A chamber which is enclosed or defined by the
insides of the platform elements directed towards the rotor axis is
thus likewise triangular-shaped. It is called a "central chamber"
within the scope of the invention. The platform elements of the
triangle are particularly dimensioned sufficiently large so that
the triangular-shaped central chamber can shelter an operator, e.g.
a maintenance technician.
[0025] A triangular shape of the platform offers the advantage that
an alignment of the standing surfaces can be coordinated
particularly simply with a position of the rotor blades when the
rotor of the wind turbines has three rotor blades. If the platform
is formed as an equilateral triangle, then it can be positioned
relative to the hub so that during a rotor rotation about
120.degree. a change always takes place from a first standing
surface in a horizontal position to a second standing surface in a
horizontal position. The platform according to the invention thus
reduces the dependency of the horizontal position of a standing
surface on a position of the rotor blades.
[0026] Advantageously at least one of the platform elements
comprises at least one opening as access for an operator. It is
advantageous if all the platform elements comprise an opening. The
opening(s) can advantageously have a dimension, or in the case of a
circular opening, a diameter, which is large enough so that an
operator can pass from any hollow chamber region through the
opening into another hollow chamber region. The operator can pass
from a chamber inside the hub into the hollow chamber between the
hub and the rotor housing. He can then step from the chamber first
into a region inside the triangular platform, the "central
chamber". From there the opening according to the invention in one
or in each platform element allows access to one or any further
hollow chamber region, wherein the access leads each time through a
hollow chamber region inside the platform respectively to the
"central chamber".
[0027] In principle an opening in the platform element can be
opened permanently during operation of the safety device. In
particular the safety device comprises a closing element for
closing the opening. The closing element can be a flap, a sliding
door, or a roller shutter which allows an opened and a closed state
of the opening. It can also be formed as a removable cover. An
operator can cover the opening by means of the closing element
after passing through. The closing element is particularly designed
so that it can be loaded with a weight of the operator without
opening automatically.
[0028] The further development according to the invention thus
contributes to the safety of the operator. It reduces the risk of
injury if the operator slides or falls down, for example starting
from the vertex face.
[0029] According to a configuration of the safety device the
platform comprises bridging elements which span the contact points
of the platform elements on the inner sides of the platform
elements facing a rotor axis. By "contact point" is meant a place
or spatial area where the ends of two platform elements meet one
another at an angle and are for example welded to one another. By
"inner sides" of the platform elements are meant those sides which
in the case of a three-dimensional shape of the platform face one
another and at the same time towards the rotor axis. The bridging
elements can be set up at any points of the inner sides. They can
have the configuration of a frame, grid or scaffold, and can be of
the same or different size. They can be fastened on the platform
elements by means of screw connections, adhesive connections, bolts
or rivets. The bridging elements may each comprise at least one
standing surface on which an operator can stand. When fitting a for
example triangular-shaped platform with for example three bridging
elements according to the invention, at least one doubling of the
standing surfaces on an inside of the platform to six standing
surfaces can be achieved by the bridging elements. With a rotation
of the rotor around 360.degree. an operator can consequently use in
six different positions of the rotor a horizontal standing surface
in an inner hollow chamber region of the platform.
[0030] The bridging elements can basically each stand at any angle
to the platform elements. The platform elements may stand on their
inner sides facing the rotor axis at an angle of 120.degree. to
inner sides of each adjoining bridging elements likewise directed
to the rotor axis. When the platform is designed as an equilateral
triangle it results therefrom that each bridging element stands
parallel to each opposite platform element. Thus with a rotation of
a rotor about 120.degree. in a starting and in an end position of
the rotational movement, two parallel floors of the platform i.e. a
platform and a bridging element, lie horizontal. Thus by way of
example it becomes clearly easier to set up a ladder on a bridging
element. The ladder can help the operator to pass from a space
inside the triangular-shaped platform to an opening arranged above
same, and then through it to a standing surface of a platform
element lying parallel above same. Consequently during a rotation
of the rotor about 60.degree. a change takes place from one
standing surface to an adjacent standing surface which then each
lie horizontal and offer the operator a safe standing surface. The
configuration according to the invention can significantly simplify
the work of a maintenance technician in the hollow chamber, for
example on the connecting flanges of the rotor blades.
[0031] In principle the platform can be fastened solely on the hub
of the rotor. According to a configuration the safety device
comprises strut elements as a fixing device which connect the
platform at contact points of the platform elements to an inner
side of the rotor housing. The strut elements can be placed at any
points on the inside of the rotor housing. They can have the form
of a frame, grid or scaffold, of the same or different size.
Furthermore they can be fastened to the platform or on the inside
of the rotor housing by means of screw connections, adhesive
connections, bolts or rivets. The strut elements can furthermore be
designed so that they divide the hollow chamber between the hub of
the rotor and an inside of the rotor housing into separate hollow
chamber regions.
[0032] The strut elements can basically be anchored at any points
of the rotor housing which surrounds the hub and connecting flanges
of the rotor blades on the hub. They are particularly fastened in
the region of interfaces of segments of the rotor housing. The
strut elements mounted on the platform thus connect the segments of
the rotor housing to one another. The platform can serve by way of
the strut elements as a reinforcement element of the rotor housing
insofar as through its shape it absorbs the tensile forces acting
on a housing segment of the rotor much more effectively than an
adjacent housing segment. Fastening the strut elements on
interfaces of the housing segments furthermore offers the advantage
that fastening means, for example flat angle plates, are usually
already provided at the interfaces which the strut elements can use
for connection. Furthermore a single strut element can thereby be
fitted at the ends of two housing segments of the rotor and
stabilize them.
[0033] The platform is particularly likewise also mounted on the
hub so that the segments of the rotor housing not only support one
another, but ultimately are fastened on the hub of the rotor. The
strut elements can thereby replace or support any other
reinforcement elements which connect the hub, a rotor housing as
well as a rotor hood, structurally to one another. The
configuration according to the invention thus serves as a
structural element of a rotor and stabilises the rotor housing
which increases its resistance for example to acute wind loads. The
safety device thus offers a valuable synergy effect.
[0034] The strut elements can run substantially parallel to a
longitudinal axis of a blade of the rotor between interfaces of
segments of the rotor housing and the platform. The safety device
with the elements of the platform elements, the bridging elements
and the strut elements can be constructed symmetrically, e.g.
three-fold radially symmetrically. Such a design can enhance the
working safety of the operator since the safety device has the same
configuration each time in three different positions of the rotor.
The operator is thus not forced to get used to or adapt to
different forms and sizes of plates, standing surfaces, openings,
which can take up part of his attention and in some circumstances
can lead to a loss of time or accidents. Rather he discovers a
uniformly configured working environment.
[0035] The platform elements, bridging elements and strut elements
can basically each have a quite different shape. By way of example
the platform elements can be designed flat, whilst the strut
elements can on the other hand be grid-like structures. The
platform elements and/or the bridging elements and/or the strut
elements are particularly designed as flat plates. The flat plates
can be by way of example metal plates, for example made of
corrosion-resistant stainless steel or aluminium. Alternatively
they can be made of plastics, e.g. of glass fibre reinforced
plastics, of wood or of carbon fibre.
[0036] It is advantageous if the platform elements, bridging
elements and strut elements are formed solely as plates. They each
provide smooth standing surfaces which guarantee a particularly
high working safety by not offering any engagement points for
catching or clamping on an operator, which can lead for example to
tripping and falling. The plates according to the invention can
thereby provide the platform elements, bridging elements and strut
elements with two standing surfaces lying parallel to one another
on a front and a rear side.
[0037] The plates may extend continuously or substantially without
any gaps between an outer side of the hub and an inner side of the
rotor housing so that they pass through the entire hollow chamber.
The plates thus ensure that an operator in the event of falling
down, for example from a vertex face, does not unintentionally pass
from one hollow chamber region into another hollow chamber region
or becomes jammed in an interspace. The same advantage is produced
for tools or spare parts which an operator may be carrying loose
with him; should they become undesirably lost or dropped they are
prevented from slipping through into another hollow chamber region
and can be quickly found again by the operator.
[0038] Furthermore the plates offer the advantage that they can
connect a rotor hood to the hub and can thus additionally
strengthen a structure of the rotor housing. The plates therefore
may have fastening elements for fastening the rotor hood on the
platform. The fastening elements can comprise for example angle
plates which are fixed on the plates or the rotor hood by means of
rivets or screw connections.
[0039] According to a configuration of the safety device an
extension of the platform elements in a direction substantially
transversely or vertically to the rotor axis comprises at least 1
m, particularly at least 1.3 m and more particularly at least 1.5 m
as well as at most 5 m, particularly at most 4 m and more
particularly at most 3 m. This extension permits an optimum
adaption of the safety device to rotors, more particularly of wind
turbines which have a different size and power performance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] The invention will now be explained below once more in
further detail with reference to the accompanying drawings and
using embodiments. The same components in the different figures are
thereby provided with identical reference numerals. The drawings
show:
[0041] FIG. 1 a perspective illustration with a partial section of
a rotor housing according to the prior art;
[0042] FIG. 2 a perspective partial section from the right of a
rotor housing with an embodiment of the safety device according to
the invention;
[0043] FIG. 3 a side view from the right of the rotor of a wind
turbine with the safety device;
[0044] FIG. 4 a front view of a rotor housing with the safety
device; and
[0045] FIG. 5 a diagrammatic front sectional view of a rotor
housing with the safety device.
DETAILED DESCRIPTION OF INVENTION
[0046] FIG. 1 shows a section of a rotor 1 of a wind turbine with a
hub 3 which is surrounded by a rotor housing 12. The rotor 1 is
formed with three vanes, i.e. it has three rotor blades (not shown
in FIG. 1) protruding radially from the hub 3. Inside the hub 3
there is a tunnel-shaped hollow chamber (not shown) which serves as
access from a tower (not shown) or a nacelle (not shown) of a wind
turbine to connecting flanges 7 of the rotor blades 5 on the hub 3.
An exit 9 connects the tunnel to a dish-like maintenance chamber 21
between the hub 3 and the rotor housing 12. Three two-prong ladder
sections 10 protrude from an edge of the exit 9. An operator 16,
e.g. a maintenance technician, climbs over an upper ladder section
10 in the direction of a vertex face 4 of the hub 3. The vertex
face 4 forms a region of the curved surface of the hub 3 which lies
between the two circular connecting flanges 7 of the rotor blades 5
of the rotor 1. In the illustrated position of the hub it offers a
favourable, because substantially horizontally aligned, standing
site for the operator 16 in order to inspect or tighten bolts for
example by which the rotor blades 5 are mounted on the hub 3.
According to the prior art an operator 16 can rope himself by means
of safety harness or belts onto security points which lie on an
inner side 14 of the rotor housing 12 and/or on an outer surface of
the hub 3 so that the operator 16 is protected against sliding or
falling down.
[0047] FIG. 2 shows a safety device 19 according to the invention
on the rotor 1. A platform 20 is mounted at the front on the hub 3
of the rotor 1 and is supported by three feet as strut elements 28
or a fixing device on the inner side 14 of the rotor housing 12.
The platform 20 is fixed on the hub 3 so that it turns
automatically during a rotational movement of the rotor 1. The
rotor housing 12 includes three housing segments 13 which enclose
the hub 3, the connecting flanges 7 of the rotor blades 5 and the
platform 20. The rotor housing 12 has a front circular opening
which during operation of the rotor 1 is covered by a rotor hood
(not shown). The strut elements 28 of the platform 20 connect at
interfaces 17 between the housing segments 13. The platform 20 and
the strut elements 28 are made substantially of metal.
[0048] The platform 20 has three oblong platform elements 24 of
identical length which are brought together in the form of an
equilateral triangle. The platform elements 24 stand at internal
angles .alpha. of 60.degree. relative to one another. Each platform
element 24 has an extension of 2 m in a direction perpendicular to
a rotational axis R. At the inner sides 34 of the platform elements
24 facing the rotor axis R webs acting as bridging elements 26 span
the tips of the triangle, i.e. the seam points between two
adjoining platform elements 24. The tips are formed from contact
points 25 of the platform elements 24. Each bridging element 26
thereby stands at an angle of 120.degree. to an adjacent platform
element 24. Each bridging element 26 thereby also lies parallel to
a platform element 24 which is opposite it on the other side of a
central chamber 23 (as hollow chamber region). The platform
elements 24 furthermore each have an opening 29 or an aperture
which is covered here each time by a removable circular cover 30 as
a closing element. The covers 30 have a diameter b which is large
enough so that an operator can slip through the opening 29. The
platform 20 is measured so that the central chamber 23 is large
enough so that an operator can stop and move about therein.
[0049] Whilst the bridging elements 26 offer an operator a standing
surface 32 for standing up, the platform elements 24 each have two
potential standing surfaces 32. An inner one of these standing
surfaces 32 thereby points towards the rotor axis R, an outer
standing surface 32 points towards the rotor housing 12. In the
central chamber 23 of the platform 20 there are therefore six
potential standing surfaces 32. When any one standing surface 32 is
located in a horizontal position each rotation of the rotor 1
around 60.degree. causes a horizontal position of an adjacent
standing surface 32.
[0050] The strut elements 28 are seated on the outside at the tips
of the triangle of the platform 20. Each strut element 28 extends
substantially parallel to a longitudinal axis L of an adjacent
rotor blade 5. Since the strut elements 28 are formed as flat
plates they divide together with the platform elements 24 a
maintenance chamber 21 between the hub 3 and the rotor housing 12
(as hollow chamber) into three outer partial chambers 22 (as hollow
chamber regions) and a central chamber 23 (as hollow chamber
region), which lies inside the platform 20.
[0051] Several angle plates 38 are mounted on the platform elements
24 and fasten the platform 20 on one side on the hub 3 and on the
other side on the rotor hood (not shown).
[0052] The platform 20 according to the invention offers the
advantage that its in total nine potential standing surfaces 32 and
its openings 29 provide an operator with defined paths and handling
regions inside a maintenance chamber 21. The triangular design of
the platform 20 offers on its outer side during a rotor rotation
about 120.degree. a horizontally lying standing surface 32, and
even on its inner side facing the rotor axis R during a rotor
rotation about 60.degree.. It can thus assist or even replace a
conventional safety fitting of an operator, such as safety harness
and belts. The platform 20 furthermore considerably shortens the
fall paths of an operator, e.g. from a vertex face (not shown) of
the hub 3 starting in the direction of a connecting flange 7 of a
rotor blade 5 which in this situation points directly downwards.
The safety device 19 furthermore functions as a structural element
of the rotor 1 and serves for a reinforcement and thus stabilizing
of the rotor housing 12 with the rotor hood (not shown).
[0053] FIG. 3 shows, in contrast to FIG. 2, an operator 16, e.g. a
maintenance technician who is moving forwards in an outer partial
chamber 22 on a curved surface of the hub 3 in the direction of a
vertex face 4 of the hub 3. A horizontally aligned platform element
24 as well as the strut elements 28 which adjoin the ends of the
platform element 24 and run inclined relative to the platform
element 24 close off an upper outer partial chamber 22 from further
partial chambers 22, 23. A fall path of the operator and his
equipment, e.g. loosely carried spare parts and/or tools, is
thereby clearly shortened. A continuous extension of the platform
elements 24 and the strut elements 28 between the hub 3 and the
rotor housing 12 reliably prevents the operator and smaller
elements from becoming jammed or slipping through.
[0054] FIG. 4 shows, in contrast to FIGS. 2 and 3, the safety
device 19 according to the invention in a front view. The operator
16 stands facing the viewer on a horizontal standing surface 32 of
a bridging element 26 and has in front of him a mobile ladder 40
which is likewise standing on the bridging element 26. A spacing
between the bridging element 26 and the platform element 24 is here
greater than a body size of the operator 16. The mobile ladder 40
extends up to an open opening 29. The operator 16 when climbing up
the ladder 40 can pass through the opening 29. He can then move on
a horizontal standing surface 32 of the platform element 24. An
opening of the rotor housing 12 released by the housing segments 13
is covered by a disc-like rotor hood 15. The platform elements 24
have angle plates 38 which run along an extension of the platform
elements 24 between the strut elements 28, and fasten the platform
20 additionally on the hub 3.
[0055] FIG. 5 shows, in contrast to FIG. 4, more particularly the
three-fold radially symmetrical construction of the safety device
19 according to the invention. Each of the three strut elements 28
aligns flush with a longitudinal axis L of one of the three rotor
blades 5 or stands parallel to it. The platform 20 with its
platform elements 24 forms an equilateral triangle. A longitudinal
axis L of each rotor blade 5 stands perpendicular to an opposing
platform element 24. The strut elements 28 are mounted by means of
bolts 18 as fixing device on interfaces 17 of the segments 13 of
the rotor housing 12.
[0056] It is finally pointed out once more that the devices
described in detail above are only examples of embodiments which
can be modified by one skilled in the art in the most varied of
ways without departing from the scope of the invention. Furthermore
the use of the indefinite article "a" and "an" does not rule out
that the relevant features can also be present in several
numbers.
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