U.S. patent application number 13/509168 was filed with the patent office on 2012-09-27 for drive unit for a wind turbine.
This patent application is currently assigned to Suzlon Energy GmbH. Invention is credited to Joerg Winkelmann.
Application Number | 20120244989 13/509168 |
Document ID | / |
Family ID | 43992143 |
Filed Date | 2012-09-27 |
United States Patent
Application |
20120244989 |
Kind Code |
A1 |
Winkelmann; Joerg |
September 27, 2012 |
DRIVE UNIT FOR A WIND TURBINE
Abstract
A drive unit for a wind turbine is provided: wherein the wind
turbine comprises a rotor rotatably supported on a machine frame
with a hub and at least one rotor blade attachable thereto, wherein
the drive unit has a gear box for converting the rotational speed
of the rotor according to a gear box ratio, comprising at least one
ring gear, a planet carrier, at least two planet wheels, a sun
wheel and a output shaft, wherein the ring gear is connectable to
the rotor in a rotation-fixed manner and in effective engagement
with planet wheels, planet wheels are rotatably supported on the
planet carrier planet wheels cooperate with the sun wheel and the
sun wheel is connected with the output shaft, wherein the drive
unit has a substantially horizontal rotor shaft for rotatably
supporting the rotor, wherein the rotor shaft can be directly or
indirectly fixedly connected to the machine frame.
Inventors: |
Winkelmann; Joerg; (Wardow,
DE) |
Assignee: |
Suzlon Energy GmbH
Rostock
DE
|
Family ID: |
43992143 |
Appl. No.: |
13/509168 |
Filed: |
November 15, 2010 |
PCT Filed: |
November 15, 2010 |
PCT NO: |
PCT/EP2010/067518 |
371 Date: |
May 10, 2012 |
Current U.S.
Class: |
475/331 |
Current CPC
Class: |
F16H 1/2818 20130101;
Y02E 10/725 20130101; H02K 7/1838 20130101; H02K 7/116 20130101;
F03D 15/00 20160501; F05B 2260/40311 20130101; F05B 2260/96
20130101; F16H 1/2845 20130101; F03D 15/20 20160501; Y02E 10/72
20130101; Y02E 10/722 20130101; F03D 80/70 20160501 |
Class at
Publication: |
475/331 |
International
Class: |
F16H 1/28 20060101
F16H001/28 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 13, 2009 |
DE |
10 2009 052 809.1 |
Nov 20, 2009 |
DE |
10 2009 053 757.0 |
Claims
1. A drive unit for a wind turbine, wherein the wind turbine
comprises a rotor rotatably supported on a machine frame with a hub
and at least one rotor blade attachable thereto, wherein the drive
unit has a gear box for converting the rotational speed of the
rotor according to a gear box ratio, comprising at least one ring
gear, a planet carrier, at least two planet wheels, a sun wheel and
a output shaft, wherein the ring gear is connectable to the rotor
in a rotation-fixed manner and in effective engagement with planet
wheels, planet wheels are rotatably supported on the planet carrier
planet wheels cooperate with the sun wheel and the sun wheel is
connected with the output shaft, wherein the drive unit has a
substantially horizontal rotor shaft for rotatably supporting the
rotor, wherein the rotor shaft can be directly or indirectly
fixedly connected to the machine frame.
2. The drive unit according to claim 1, wherein the planet wheels
directly engage into the sun wheel.
3. The drive unit according to claim 1, wherein further planet
wheels are provided, which are connected in a rotation-fixed manner
to the planet wheels which are in effective engagement with the
ring gear, wherein these further planet wheels are in effective
engagement with the sun wheel.
4. The drive unit according to claim 1, wherein the ring gear is
directly or indirectly rotatably supported on the rotor shaft.
5. The drive unit according to claim 5, wherein the gear box has a
gear box bell jar which is rotatably supported on the rotor shaft
via a bearing, wherein the ring gear is arranged on the gear box
bell jar.
6. The drive unit according to claim 1, wherein the planet carrier
is fixedly connected to the machine frame.
7. The drive unit according to claim 1, wherein junctures are
provided on the rotor shaft for indirect or direct connection with
the machine frame, wherein the number of effective junctures is at
least equal to or greater than the number of planet wheels which
are in effective engagement with the ring gear.
8. The drive unit according to claim 8, wherein the junctures are
connected with the planet carrier, which is connectable to the
machine frame.
9. The drive unit according to claim 1, wherein sealing means for
sealing the gear box are effectively provided between the ring
gear, the gear box bell jar or housing and the planet carrier or
the machine frame.
10. The wind turbine comprising a tower, a machine housing
rotatably supported thereon with a machine frame, one rotor
rotatably supported on the machine frame with a hub and at least
one rotor blade attachable thereto, wherein a drive unit according
to claim 1, which is arranged on the machine frame.
11. The wind turbine according to claim, wherein the output shaft
is rotatably supported in the machine frame by means of a bearing
in such a way that an axial offset (Lx) is present between the sun
wheel and the bearing, which enables a radial clearance of the sun
wheel in cooperation with the stiffness of the output shaft
according to the guiding of the sun wheel through planet wheels in
order to prevent excessive loading of the gear box.
12. The wind turbine according to claim 11, wherein the hub of the
rotor is indirectly supported on the rotor shaft via the gear box
bell jar.
13. The wind turbine according to claim 11, wherein the hub is
directly supported rotatably on the rotor shaft via at least one
further bearing.
14. The wind turbine according to claim 1, wherein decoupling
connecting means are effectively arranged between the ring gear and
the rotor to substantially prevent transmitting of axial motions,
radial motions and/or bending motions of the hub to the ring
gear.
15. The wind turbine according to claim 1, wherein on the rotor
shaft a transmitting device for transmitting electrical energy
between to each other relatively rotating components, in particular
a slip-ring device is provided, which is connected through the
rotor shaft to a power supply and/or control unit of the wind
turbine.
Description
TECHNICAL FIELD
[0001] The invention relates to a drive unit for a wind turbine,
wherein a rotor of the wind turbine is rotatably mounted on a
machine frame. The rotor comprises a hub and at least one
attachable thereto rotor blade. The drive unit comprises a gear box
for converting the rotational speed of the rotor according to a
desired gear box ratio. The gear box, a planetary gear box
comprises at least one ring gear, a planet carrier, at least two
planet wheels, a sun wheel and an output shaft. The wheels of the
gear box are preferably designed as gears. The ring gear is
connected with the rotor in a rotation-fixed manner and is in
effective engagement with planet wheels. These are rotatably
supported on the planet carrier and again cooperate with the sun
wheel. Since the sun wheel is connected to an output shaft, the
transmitted speed can be coupled into a working machine, such as a
generator.
BACKGROUNDS
[0002] From DE 103 18 945 B3, such a gear box for a wind turbine is
known. Thereby, the rotor of the wind turbine has a hub with rotor
blades, which are supported on the hub rotatably around its
longitudinal axis. Thereby, the angle of attack of the rotor blades
in the wind flow is variable. The hub is directly connected to the
rotor shaft, which is supported by means of a main bearing on a
machine frame of the wind turbine. The fixed outer bearing shell of
the main bearing, which is connected to the machine frame,
comprises in the radial direction from outside the rotor shaft and
the inner radial bearing shell arranged firmly thereon. On the
rotor shaft, at the same the ring gear of the planetary gear box is
arranged radially internally, whereby the planet wheels are
driven.
[0003] Through this construction, it arises that the entire weight
of the rotor and the forces of the wind acting thereon must be
diverted via the main bearings into the machine frame. This is a
very high load for the bearing. In addition, a main bearing
according to the prior art shows a very large diameter. Since
manufacturing tolerances for roller bearings are very small anyway
and will also be even smaller if, as here, the bearing also carries
a part of the gear box, thus high production costs are to be
expected in the embodiment of the prior art.
SUMMARY OF INVENTION
[0004] An object of the invention is to provide a drive unit of a
wind turbine, and also such a wind turbine itself, which avoids the
disadvantages of the prior art. Thereby, especially an advantageous
and simple support for a rotor of a wind turbine with a robust and
cost-reduced drive unit should be presented.
[0005] The object is achieved with a drive unit with the features
of the independent claim 1. The invention includes, inter alia,
that the drive unit comprises a substantially horizontal rotor
shaft for rotatably supporting the rotor. The rotor shaft here
could be directly or indirectly firmly connected to the machine
frame. In this way, the advantage, that the forces and loads of the
rotor are introduced directly into the machine frame, and the main
force flow does not take place in the vicinity of the gear box and
would not lead to harmful deformations there, appears for the first
time. In addition, the supporting can be achieved on a central,
cone-shaped rotor shaft with smaller and cheaper bearings.
[0006] According to one embodiment, the planetary gear box is
formed as single-stage. In this direct effective engagement, the
gear box corresponds to a classic planet gear box. Here, the planet
wheels engage directly into the sun wheel. Here, the gear box turns
out to be particularly advantageous and preferably a gear box ratio
of about 1 to 10 is achieved. Such a wind turbine is gladly
referred to as medium-speed wind turbine.
[0007] However, it is also conceivable that more planet wheels are
provided, which are connected in a rotation-fixed manner with
planets that are in effective engagement with the ring gear. The
planet wheels are then in indirect effective engagement with the
sun wheel, but are each connected to a further planet wheel and
form a planetary pair. These further planet wheels are then in
effective engagement with the sun wheel. Thus, the gear box ratio
of the gear box can be influenced via the diameter ratios of the
planetary pairs relative to each other. When the diameter of the
first planet wheels which are in engagement with the ring gear is
smaller than the diameter of the further planet wheels, then the
ratio of the gear box is increased in contrast to the direct gear
box variant.
[0008] A non-illustrated embodiment particularizes a multi-stage
planetary gear box, wherein the sun wheel of the first planetary
stage drives, for example, a ring gear of the following stage.
[0009] Advantageously, the gear box comprises three or four planet
wheels, because this will cause that the ring gear is better
supported via the planet wheels, that is, that radial and
circumferential forces are transmitted to a planet carrier.
Moreover, the sun wheel and the output shaft are also supported
through the planet wheels in the radial direction. To achieve an
optimal gear box behavior, the ring gear, planet wheels and the sun
wheel are formed as gear wheels.
[0010] A remarkable feature of this invention is that preferably
exclusive and no more than one output shaft is provided, which is
driven exclusively by only one sun wheel. Because then a load
distribution takes place onto different planet wheels towards the
sun wheel. It should be emphasized that in case of a multi-stage
planet gear box, the gear box shaft between the first and the next
stage is not regarded as output shaft within the meaning of the
preceding disclaimer. Because then a plurality of output shafts
connected in series are provided, wherein only one could be
connected to, for example, a generator for producing electric
current. In the case of several output shafts, disadvantageously,
several generators would have to be used in parallel.
[0011] According to a preferred embodiment of the invention, the
ring gear is rotatably supported on the rotor shaft. Thereby, the
supporting of the ring gear is avoided through an expensive
external bearing with a large diameter. Here, the supporting of the
ring gear can be achieved via the bearings of the hub of the wind
turbine without using a own separate bearing. This leads to a
reduction of the components and thus to reduced cost.
[0012] One embodiment of the invention discloses that the ring gear
is supported via its own separate bearing on the rotor shaft. Here,
the gear box can have a gear box bell jar, which is rotatably
supported via a bearing on the rotor shaft, on which the ring gear
is arranged. The hub of the wind turbine here can have its own
separate bearing for supporting on the rotor shaft. This own
supporting of the hub and the gear box acts here particularly
positively on the load of the gear box, since thereby relative
motions of a driving hub can not be transmitted to the gear
box.
[0013] According to a further embodiment of the invention, the
planet carrier is arranged in the wind turbine in a rotation-fixed
manner relative to the machine frame or the rotor shaft. In
particular, junctures are provided on the rotor shaft for
indirectly or directly, fixedly connecting to the machine frame and
for transmitting forces. The number of effective junctures should
be at least equal to or greater than the number of planet wheels,
which are in effective engagement with the ring gear.
[0014] Furthermore, the junctures may again be connected to the
planet carrier; said planet carrier is again connected to the
machine frame. It is conceivable here that the planet carrier is
formed as a disc, which can be screwed to the machine frame. On
this disc, in the case of a planetary gear box with three planet
wheels, three bearing pins for the planet wheels are either
provided fixedly and integrally, or can be screwed on, for example,
through anchor screws. It simplifies the production of the planet
carrier immensely if this is formed in several pieces with respect
to the machine frame, as a rotationally symmetric disk can be
manufactured in an accurately fitting manner much easier through
rotational machining processing than a bulkier and heavier machine
support of the wind turbine. The rotation axis is again fixed on
the planet carrier via the junctures, preferably through screws,
which extend until into the machine frame. Here, the connection
points grasp the planet carrier nearby the individual planet
wheels.
[0015] If the producing allows, then, of course, the planet carrier
can be formed integrally with the machine frame, on which the rotor
shaft can be directly installed then. In this case, the bearing
pins for the planet wheels are also formed integrally with the
machine frame or a transition region of the rotor shaft or mounted
as separate bearing pins into the machine frame, into the rotor
shaft or into both.
[0016] It is also conceivable--but not necessarily--that the planet
wheels are supported in the transition region of the rotor shaft
towards the junctures, which means that the planet carrier is
formed directly with the rotor shaft, preferably as an integral
component.
[0017] Since the gear box requires oil lubrication, an embodiment
shows that sealing means for sealing the gear box are effectively
provided between the ring gear or the gear box bell jar and the
planet carrier or the machine frame. Depending on the
characteristics of the invention, the sealing means are effectively
arranged on the components which perform a relative motion,
rotation--standstill, to each other.
[0018] The invention also comprises a wind turbine with a drive
unit according to the above-described embodiments. Such a wind
turbine presents a machine housing mounted on a tower with the
machine frame. The rotor with the hub and at least one rotor blade
that can be attached thereto is rotatably supported on the machine
frame. This wind turbine shows obvious advantages in terms of
reduced complexity, cost, and increased life span relative to other
wind turbines according to the prior art.
[0019] Advantageously, the wind turbine is formed in such a manner
that an axial offset exists between the sun wheel and a bearing of
the output shaft of the gear box. Thus, in cooperation with the
flexibility of the output shaft, a radial clearance of the sun
wheel is achieved according to the guide of the sun wheel by planet
wheels to prevent excessive load of the gear box and the
bearing.
[0020] As described above, according to an embodiment, the ring
gear is supported on the rotor shaft with its own bearing via a
gear box bell jar. According to a preferred embodiment it is
provided to support the hub of the rotor indirectly on the rotor
shaft via the gear box bell jar or via the ring gear.
[0021] However, advantageously, at least one, but preferably two
separate bearings are provided for the hub to support on the rotor
shaft.
[0022] In order to achieve a particularly long service life and low
load of the gear box, decoupling connecting means are effectively
arranged between the ring gear and the rotor, in particular between
ring gear and the hub, in order to substantially prevent
transmitting of axial motions, radial motions and/or bending
motions of the hub to the ring gear. This decoupling protects the
gear box against unwanted deformations. A distribution of load
takes place through the advantageous separate supporting of ring
gear and rotor: the rotor shaft carries weight, thrust-,
transverse- and bending forces, wherein circumferential
forces--quasi free of disturbing forces--are alone transmitted to
the gear box.
[0023] Another embodiment of the invention teaches to provide on
the rotor shaft a transmitting device for transmitting electrical
energy between components rotating relatively to each other, in
particular a slip ring device. Here, passing through the rotor
shaft, a power supply is achieved with the power grid of the
machine housing, for example via cable, in order to drive the
electrical components in the hub, such as the motors for the blades
adjusting. Thereby, a transfer of control signals can also be
realized.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Further details of the invention will become apparent from
the drawings on the basis of the description.
[0025] In the drawings
[0026] FIG. 1 shows an exemplary wind turbine,
[0027] FIG. 2 shows a longitudinal section through a wind turbine
with a first embodiment of drive unit according to the
invention,
[0028] FIG. 3 shows a cross section through the drive unit
according to FIG. 2, 3 or 4,
[0029] FIG. 4 shows a wind turbine according to FIG. 2 with a
second embodiment of a drive unit,
[0030] FIG. 5 shows a wind turbine according to FIG. 2 with a third
embodiment of a drive unit,
[0031] FIG. 6 is a schematic diagram of a wind turbine with a
fourth embodiment of the drive unit.
PREFERRED EMBODIMENTS
[0032] To make the context of the invention clearly, in FIG. 1 an
exemplary wind turbine 1 is shown. This comprises a tower 2, a
machine housing 3 and a rotor 7, wherein the machine housing 3 is
supported rotatably on the tower 2 around a substantially vertical
axis 4 by means of an azimuth bearing 5 in order to allow wind
tracking. The rotor 7 is arranged on the machine housing 3, which
comprises a hub 8, on which again preferably three rotor blades 9
are arranged. The rotor 7 is supported on the machine frame 6 via
the drive unit 10 according to present invention and drives a
generator 32 for producing electric current.
[0033] FIG. 2 shows the first embodiment of the drive unit 10 of
the wind turbine 1. However, the details described below
substantially refer to other embodiments. FIG. 2 shows primarily
the machine housing 3, the drive unit 10 and the rotor 7. A machine
frame 6 in the machine housing 3 is connected with the azimuth
bearing 5, whereby the machine housing 3 is supported on the tower
2 of the wind turbine 1 rotatably around the axis 4 by means of the
azimuth bearing 5. The preferably cone-shaped rotor shaft 11 is
arranged in a rotation-fixed manner again on the machine frame 6
via junctures 15, wherein the rotor shaft 11 and the junctures 15
can be formed integrally. The hub 8 is rotatably supported on the
rotor shaft 11, wherein this extends substantially horizontally.
The hub 8 comprises an access opening 39 to allow an access for
machinists into the hub 8 in case of maintenance. In order to
orientate, an axial direction 12, a radial direction 13 and a
circumferential direction 14 are defined with respect to this axis
of rotation or the rotor shaft 11 of the rotor 7, which also
applies to the following embodiments.
[0034] The hub 8 of the rotor 7 is connected in a rotation-fixed
way to a ring gear 20 of a gear box 18 via elastic connecting means
17 via a gear box bell jar 19, wherein the gear box bell jar 19 and
the ring gear 20 may be formed as one piece. Thus, the ring gear 20
takes the same rotation as the rotor 7. The rotational motions of
the ring gear 20 is further transmitted to planet wheels 23, which
are rotatably supported in a planet carrier 26 by means of bearing
pins 25. The planet carrier 26 is provided in a rotation-fixed
manner relative to the machine frame 6, in particular, the planet
carrier 26 can be formed, according to FIG. 2, by a transition
region 16 of the rotor shaft 11 to the junctures 15, or according
to FIG. 4, via a separate planet carrier 47, or according to FIG.
5, directly from the machine frame 6. To some extent, the ring gear
20 is supported via the planet wheels 23 on the machine frame 6 or
on the rotor shaft 11.
[0035] In present embodiments, three planet wheels 23 are provided,
wherein this is not to act in a limiting way on the invention, but
two, four, five or six planet wheels are also conceivable.
[0036] The ring gear 20 is connected to a housing 22 and a gear box
bell jar 19 and forms a structural unit, which is connected to the
hub 8 in a rotation-fixed manner via the connecting means 17 and
consequently rotates together with the rotor 7. The initial
rotation of the rotor 7 is transmitted via the ring gear 20 to the
planet wheels 23 and--now at a higher rotational speed--transmitted
to the sun wheel 29 in the center of the gear box 18. The sun wheel
29 is connected to an output shaft 31, which further transmits the
rotation at a medium-fast, increased rotational speed to a
generator 32 for producing electric current. The output shaft 31 is
preferably provided with a braking disc 33, wherein a
non-illustrated brake device can act on it for the mechanical
braking of the drive train or of the drive device 10.
[0037] The output shaft 31 is either supported directly in the
machine frame 6 and/or on the machine frame 6 via a common bearing
34 with the generator 32. The common bearing 34 of generator 32 and
output shaft 31 is particularly simple and advantageous in terms of
manufacturing and assembly of the wind turbine 1. This combined
bearing 34 here can be used particularly well, since the three or
more planet wheels 23 present also an effective supporting in the
radial direction 13, whereby an another bearing nearby the sun
wheel 29 may be abandoned. Between the bearing 34 of the output
shaft 31 and the sun wheel 29, an axial offset Lx exists. Because
of the fact that the output shaft 31 can deform slightly
elastically, the sun wheel 29 is capable of performing a radial
motion between the planet wheels 23 to some conditional extent and
thus to ensure a similar load situation between the planet wheels
23. This reduces the wear of the planet wheels 23 and the sun wheel
29.
[0038] FIG. 3 shows a simplified section through the gear box 18
along the line A-A of according to FIG. 4. Since the present
embodiments do not differ significantly in terms of the gear box
18, this also applies to the other embodiments. In FIG. 3, adjacent
to the rudimentarily illustrated rotor blades 9, the housing 22 of
the ring gear 20 can be seen, wherein the ring gear 20 is only
shown on the basis of the center circle of the dash-dot line
representing the tooth 21. The housing may be formed integrally
with the ring gear. It is also conceivable, however, to shrink the
ring gear 20 as a full-ring into the housing 22 or bring it into
the housing 22 in segments via form- or friction-fit.
[0039] Further radially inwards, a dotted line 16 can be seen,
which represents the transition region 16 between the rotor shaft
10 and the three junctures 15. This transition region 16 is used in
the embodiment shown in FIG. 2 as a receiver for the bearing pin 25
and, consequently, as a planet carrier 26. The rotor shaft 10 for
supporting the hub 8 and the ring gear 20, the transition region 16
formed as a planet carrier 26, and the junctures 15 for attaching
onto the machine frame 6 then form an integral structural unit,
which can be produced, for example, as a cast.
[0040] However, it may also be advantageous in terms of assembly
and manufacturing, to produce this structural unit from several
parts, for example according to FIG. 4.
[0041] The planet wheels 23 engages with the tooth 21 of the ring
gear 20 and the tooth 30 of the sun wheel 29, wherein the teeth 24
of the planet wheels 23 is shown as a dash-dot line 24 (center
circle).
[0042] Radially further inward, a further dotted line 44 can be
recognized, which represents the rotor shaft 11 and the bearing
surface 44 on the rotor shaft 11 of the bearing 36, 46 of the gear
box bell jar 19.
[0043] The above embodiments apply generally to all wind turbines
in accordance with FIGS. 2, 4 and 5. In following, the main
differences of the present embodiments are given--these differences
concern the supporting of the hub on the rotor shaft, the formation
of the planet carrier and the rotary connection between the ring
gear and the hub. The characteristic differences disclosed in
following embodiments are not tied to the respective embodiment and
are not to act in a limiting way on the invention, but the
characteristics of the different embodiments could be combined with
each other. In particular, the different forms of direct or
indirect supporting of the hub on the rotor shaft or the different
coupling types of rotary connection between the hub and ring gear
can be combined with the different characteristics of the planet
carrier.
[0044] In FIG. 2, the hub 8 is supported via a direct bearing 35 at
the tip 37 of the rotor shaft 10 and indirectly via a bearing 36 of
the gear box bell jar 19 of the ring gear 20 on the rotor shaft 10.
Since the hub 8 can perform a motion 38 together with the tip 37
due to bending, however this shall not be transmitted to the ring
gear 20, decoupling and/or damping connecting means 17 are provided
between the hub 8 and the gear box bell jar 19. These enable that a
substantially rotation-fixed connection is established between hub
8 and gear box bell jar 19 or ring gear 20, however no significant
axial motions can be transmitted. Such motions would result in that
the engagement of the ring gear 20 and the planet wheels 23 would
be very irregular and variable, whereby it would come to a very
high wear of the teeth or the destruction. The embodiment in FIG. 2
requires that the connecting means 17, the hub 8 and the gear box
bell jar 19 do not decouple with respect to the radial motions,
since the supporting of the hub 8 is achieved via the bearing 36 of
the gear box bell jar 19 or the ring gear 20 in a combined manner,
wherein a radial support is indispensable. The connecting means 17
may also absorb torsional vibrations.
[0045] The connecting means 17 according to FIG. 2 may be
implemented, for example, as a bush, wherein an elastomeric body 40
is arranged in or on the hub 8, or in the gear box bell jar 19 (not
shown). The elastomeric body 40 again accommodates a bolt 41, which
is fixedly arranged in the gear box bell jar 19 or in the hub (not
shown). Here, the bush is formed in such a manner that the bolt 41
is relatively flexibly supported in the axial direction 12, but not
in the radial direction 13. Preferably, three or more such
connecting means 17 are provided between the hub 8 and gear box
bell jar 19.
[0046] Sealing means 27, which seal the gear box 18 relative to the
machine frame 6, are provided on the housing 22 of the gear box
18.
[0047] With reference to FIG. 4, a further embodiment of the
invention is introduced, wherein the hub 8 is supported on the
rotor shaft 10 by means of two direct, separate bearings 42, 45.
Advantageously, one of the bearings 42, 45 is designed as a fixed
bearing and one as floating bearing. The gear box bell jar 19 and
the ring gear 20 have their own independent bearing 46 for
supporting on the rotor shaft 10. Connecting means 47, which
decouple with respect to axial and radial motions and can also be
designed as a bush, are now arranged between the hub 8 and the ring
gear 20. This brings the great advantage that now the ring gear 20
and the hub 8 are substantially decoupled in the radial direction
13 and axial direction 12 and no interfering motions 38 can be
transmitted from the rotor 7 to the gear box 18. According to FIG.
4, the decoupling means 47 is formed in such a manner that the hub
8 and the gear box bell jar 19 have areas which overlap in the
axial direction 12, but are offset in the circumferential direction
14. Between these areas of the hub 8 and the gear box bell jar 19,
elastomeric bodies 48 are provided, which although transmit
tangential forces from the hub 8 to the gear box bell jar 19, and
vice versa, but allow to some extent the axial and radial
displacement of hub 8 and the gear box bell jar 19 relative to each
other. Thus, an advantageous and effective gear box of the
rotational motion is achieved, without transmitting the harmful
radial and axial motions 38.
[0048] To achieve a low-cost manufacturing of individual
components, an independent expression of the planet carrier 49 is
proposed, as shown in FIG. 4. This consists substantially of a disc
50, which again carries the bearing pin 51 of the planet wheels 23.
The disc 50 can be produced very accurately and economically
through turning and/or milling processes and thus mounted with
screw connections on the machine frame 6. As the disc 50 of the
planet carrier 23 accommodates also the junctures 15 of the rotor
shaft 11, mainly by screw connections, the disc 50 determines the
axial spacing of the individual gears 23 of the gear box 18, which
are highly relevant to the functioning and service life of the gear
box 18.
[0049] Sealing means 52 are arranged between the disk 50 of the
planet carrier 49 and the housing 22 of the ring gear 20.
[0050] Furthermore, FIG. 5 shows that however it is conceivable in
all other embodiments to provide a transmitting device 53 on the
rotor shaft 11 for transmitting electrical energy between the rotor
shaft 11 and the hub 8 which rotates relative to the rotor shaft.
This device formed as a slip ring device comprises one or more
collectors 54 rotating with the hub 8 and the slip ring 55
connected with the hub 8. The multi-pole slip-ring 55 is connected
by cable to the power grid of the machine housing and connected to
the controlling device of the wind turbine 1 for transmitting
control signals.
[0051] The embodiment shown in FIG. 5 corresponds to the foregoing
in many respects, wherein the rotor shaft 11 is formed as a stub
axle 56 without tip. Instead, the rotor 7 is supported on the stub
axle 56 over the hub 8 via a so-called torque bearing 43. This
leads to a reduction in weight and meanwhile enlarges the space
inside the hub 8, in order to accommodate here drive components for
adjusting the angle of attack of the rotor blades 9.
[0052] The planet carrier 26 here is formed directly by the machine
frame 6, wherein the bearing pins 25 are arranged in the material
of the machine frame 6.
[0053] FIG. 6 schematically illustrates a more detailed embodiment
of the gear box 18 in accordance with FIG. 2, 4 or 5. It is here
essential that the planet wheels 23 do not directly act on the sun
wheel 29, but each planet wheel 23 in effective engagement with
ring gear 20 is assigned with a further planet wheel 57. Thus, the
ring gear 20 drives a planetary pair 58, wherein the further planet
wheel 57 acts on the sun wheel 29 respectively. So the gear box
ratio can be influenced by the proportions of planetary pairs 58
relative to each other.
TABLE-US-00001 List of reference signs 1 drive shaft 2 tower 3
machine housing 4 axis 5 azimuth bearing 6 machine frame 7 rotor 8
hub 9 rotor blades 10 drive unit 11 rotor shaft 12 axial direction
13 radial direction 14 circumferential direction 15 junctures 16
transition region 17 connecting means 18 gear box 19 gear box bell
jar 20 ring gear 21 teeth (ring gear) 22 housing 23 planet wheels
24 teeth (planet wheel) 25 bearing pins 26 planetary carrier 27
sealing means 29 sun wheel 30 teeth (sun wheel) 31 output shaft 32
generator 33 braking disc 34 bearing (generator) 35 bearing (tip)
36 bearing (combined bearing) 37 tip 38 motion 39 accessing opening
40 elastomeric body 41 bolts 42 bearing (tip) 43 torque bearing 44
bearing surface 45 bearing (hub) 46 bearing (gear box bell jar) 47
connecting means 48 elastomeric body 49 planetary carrier 50 disc
51 bearing pins 52 sealant 53 transmitting device 54 collectors 55
slip ring 56 stub axle 57 planet wheel 58 planetary pair Lx axial
offset
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