U.S. patent application number 16/996568 was filed with the patent office on 2020-12-03 for electric generator having multiple electrical machines.
The applicant listed for this patent is DDIS. Invention is credited to Jean-Marc CANINI.
Application Number | 20200381967 16/996568 |
Document ID | / |
Family ID | 1000005022964 |
Filed Date | 2020-12-03 |
United States Patent
Application |
20200381967 |
Kind Code |
A1 |
CANINI; Jean-Marc |
December 3, 2020 |
ELECTRIC GENERATOR HAVING MULTIPLE ELECTRICAL MACHINES
Abstract
An electric generator that converts mechanical energy to
electrical energy includes, among other things, a first axial flow
electrical machine that includes a first rotor mounted in rotation
about a first axis and surrounding a first stator; a second axial
flow electrical machine that includes a second rotor coaxial to the
first rotor and surrounding a second stator; and first azimuthal
securing means that joins together the first and second rotors so
that the first and second rotors can be simultaneously set in
rotation about the first axis. The electrical generator may be used
as part of a wind turbine.
Inventors: |
CANINI; Jean-Marc; (Aibes,
FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DDIS |
Anzin |
|
FR |
|
|
Family ID: |
1000005022964 |
Appl. No.: |
16/996568 |
Filed: |
August 18, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16524218 |
Jul 29, 2019 |
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16996568 |
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16134160 |
Sep 18, 2018 |
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16524218 |
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15787190 |
Oct 18, 2017 |
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16134160 |
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14432491 |
Mar 31, 2015 |
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PCT/FR2013/052120 |
Sep 17, 2013 |
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15787190 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F03D 9/25 20160501; H02K
1/28 20130101; H02K 1/2793 20130101; H02K 7/183 20130101; H02K
1/182 20130101; F03D 13/20 20160501; F03D 80/60 20160501; H02K
1/148 20130101; H02K 2213/12 20130101; H02K 1/30 20130101; Y02E
10/72 20130101; F03D 80/70 20160501; F03D 3/00 20130101 |
International
Class: |
H02K 1/30 20060101
H02K001/30; F03D 80/60 20060101 F03D080/60; F03D 9/25 20060101
F03D009/25; H02K 1/14 20060101 H02K001/14; H02K 1/18 20060101
H02K001/18; H02K 1/28 20060101 H02K001/28; H02K 7/18 20060101
H02K007/18; F03D 3/00 20060101 F03D003/00; H02K 1/27 20060101
H02K001/27 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 1, 2012 |
FR |
1259253 |
Claims
1. An electric generator allowing the conversion of mechanical
energy to electrical energy, comprising at least: a first axial
flow electrical machine comprising a first rotor mounted in
rotation about a first axis and surrounding a first stator to
generate a first magnetic flow; a second axial flow electrical
machine comprising a second rotor separate from the first rotor,
which is coaxial to the first rotor and surrounds a second stator
to generate a second magnetic flow; and first azimuthal securing
means to secure the first and second rotors so that the first and
second rotors can be simultaneously set in rotation about the first
axis to generate the first and second magnetic flows
simultaneously.
2. The electric generator according to claim 1, wherein the first
azimuthal securing means also form axial securing means to secure
together the first and second rotors along the first axis.
3. The electric generator according to claim 1, wherein the first
and second rotors each comprise first and second walls arranged on
either side of the first and second stators respectively, so as to
respectively define a first annular housing and a second annular
housing configured to receive the first and second stators
respectively, the second wall of the first rotor and the first wall
of the second rotor being arranged facing one another and the first
azimuthal securing means being configured to join together the
second wall of the first rotor and the first wall of the second
rotor in an azimuthal direction.
4. The electric generator according to claim 3, wherein the first
azimuthal securing means comprise a slide connection configured to
allow radial movement of the second wall of the first rotor
relative to the first wall of the second rotor when assembling the
electric generator.
5. The electric generator according to claim 4, wherein the slide
connection comprises an outer slide formed on one of the walls from
among the second wall of the first rotor and the first wall of the
second rotor, and an inner slide formed on the other of the walls
from among the second wall of the first rotor and the first wall of
the second rotor, the inner and outer slides being configured so
that the inner slide slides in the outer slide when assembling the
electric generator.
6. The electric generator according to claim 5, wherein the slide
connection has a dovetail-shaped profile.
7. The electric generator according to claim 1, wherein one of the
first and second rotors is composed of at least two sections and of
assembly means allowing the assembling together of the two
sections, the first azimuthal securing means being arranged on at
least one of the sections.
8. The electric generator according to claim 1, further comprising:
attaching means to secure the first and second stators.
9. The electric generator according to claim 1, further comprising:
a third axial flow electrical machine comprising a third rotor
coaxial to the first rotor and surrounding a third stator to
generate a third magnetic flow, the electric generator further
comprising second azimuthal securing means to secure the third
rotor to one of the first and second rotors so that the first,
second and third rotors can be simultaneously set in rotation about
the first axis to generate the first, second and third magnetic
flows simultaneously.
10. A wind turbine comprising a tower and a hub mounted in rotation
relative to the tower about an axis of rotation, the hub being
driven in rotation by a spinner, wherein the wind turbine also
comprises an electric generator according to claim 1, the first and
second rotors being mounted in rotation about the axis of
rotation.
11. The wind turbine according to claim 10, wherein at least one of
the first and second rotors comprises attaching means configured to
attach at least one of the first and second rotors to the hub.
12. The wind turbine according to claim 10, further comprising: a
flange connecting the hub to at least one of the electrical
machines, perforations being made in the flange to allow the
ventilation of the at least one of the electrical machines.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Non-provisional
application Ser. No. 16/524,218 filed 29 Jul. 2019 (now allowed),
U.S. Non-provisional application Ser. No. 16/134,160 filed 18 Sep.
2018 (abandoned), which claims the benefit of U.S. application Ser.
No. 15/787,190 filed on 18 Oct. 2017, (abandoned), which is a
continuation of U.S. application Ser. No. 14/432,491 filed on 31
Mar. 2015, (abandoned), which is a U.S. National Stage application
of International Application No. PCT/FR2013/052120 filed 17 Sep.
2013, which claims priority to French Application No. 1259253 filed
1 Oct. 2012, the entire disclosures of which are hereby
incorporated by reference in their entireties.
BACKGROUND OF THE INVENTION
[0002] The subject of the present invention is an electric
generator allowing the conversion of mechanical energy to
electrical energy.
[0003] In its main application the electric generator is used for
converting the mechanical energy of a wind turbine. However, the
electric generator can also be used in numerous other sectors, such
as electricity power stations grouped with a steam turbine or gas
turbine, or in hydraulic power stations.
[0004] In the remainder of the application, the advantages are
detailed of an electric generator comprising at least one
electrical machine, the electrical machine being an axial flow
alternator able to be integrated in a wind turbine.
[0005] On the basis of this example, persons skilled in the art
will easily infer the adaptations required to produce the electric
generator for other applications such as those aforementioned.
[0006] For several years, the dimensions of wind turbines and in
particular the diameter of their blades have undergone considerable
increase to obtain very high electric power without multiplying the
number of wind turbines. Thereafter the electrical machines
equipping these wind turbines have become increasingly more
voluminous.
[0007] These changes to the size of electrical machines require the
adapting of production tooling, complicate installation and
maintenance, increase manufacturing and installation costs and
accentuate the visual impact of such devices.
[0008] One solution is proposed in document FR 2 926 935 held by
the applicant, which describes an electrical machine comprising a
rotor surrounding a stator, the rotor and stator both being formed
of different sections joined to one another. The structure of the
rotor and of the stator therefore allows electrical machines to be
produced of varying size, using one and the same production
tooling, and being easier to install than electrical machines of
same size comprising a rotor and stator each formed of a single
piece.
[0009] However this solution does not solve all the problems
previously mentioned amongst which the visual impact of wind
turbines of large size.
SUBJECT AND SUMMARY OF THE INVENTION
[0010] It is the objective of the present invention to propose an
electric generator allowing very high electrical power to be
obtained without a significant increase in the dimensions of the
electric generator. This objective is reached through the fact that
the invention concerns an electric generator allowing the
conversion of mechanical energy to electrical energy, the electric
generator at least comprising:
[0011] a first axial flow electrical machine comprising a first
rotor mounted in rotation about a first axis and surrounding a
first stator to generate a first magnetic flow;
[0012] a second axial flow electrical machine comprising a second
rotor separate from the first rotor, which is coaxial to the first
rotor and surrounds a second stator to generate a second magnetic
flow;
[0013] first azimuthal securing means to join the first and second
rotors so that the first and second rotors can be simultaneously
placed in rotation about the first axis for the simultaneous
generation of the first and second magnetic flows.
[0014] This device therefore allows the accumulation of the
electric powers generated by the first and second electrical
machines, to obtain greater electrical energy than would be
obtained by an electric generator only comprising one of the first
and second electrical machines.
[0015] By azimuthal is meant the direction perpendicular both to
the axial direction of the first and second rotors, defined by the
first axis about which the first and second rotors are rotatably
mounted, and to the radial direction of the first and second
rotors, defined by one of the radii of one of the first and second
rotors. Azimuthal joining has the effect that the first and second
rotors cannot rotate relative to one another about their axial
directions. Said otherwise, azimuthal joining of two rotors
prevents relative azimuthal movement between these two rotors. The
rotation of one of the rotors therefore causes the rotation of the
other.
[0016] Since the first and second rotors are secured to one
another, they are set in rotation simultaneously, for example but
not limited thereto by the hub of a wind turbine.
[0017] In addition, the complexity of the manufacture of the
electric generator of the present invention is similar to that of
the manufacture of each of the first and second electrical
machines; its manufacturing cost is equal to or slightly higher
than the manufacturing costs of the first and second electrical
machines.
[0018] Its installation and maintenance are significantly
simplified compared with an electric generator generating similar
electrical power and comprising a single electrical machine, the
dimensions of this single electrical machine being substantially
larger than those of each of the first and second electrical
machines forming the generator of the present invention.
[0019] In the event of faulty functioning of one or other of the
electrical machines, the electric generator of the present
invention is able to continue generating electric energy, the
electric generator thereby remaining available. This characteristic
is particularly advantageous when the electric generator is used to
equip a wind turbine installed in areas having difficult access, in
open sea for example, the servicing time to repair the faulty
element then possibly being particularly lengthy.
[0020] The radial bulk of the electric generator of the present
invention is the same as that of an electrical machine of larger
size.
[0021] By radial bulk of the generator is meant the span defined by
the first and second electrical machines in a plane perpendicular
to the first axis.
[0022] Preferably, the first and second rotors respectively
surround the first and second stators circumferentially.
[0023] In other words, the first and second rotors extend along the
respective circumference of the first and second stators,
surrounding the same.
[0024] It will therefore be understood that the first and second
rotors each define an annular cavity or housing configured to
receive the first and second stators respectively.
[0025] The annular housings thus defined by the first and second
rotors are joined together by the first azimuthal securing
means.
[0026] Preferably, the first and second electrical machines are
identical, so that the complexity of the manufacture of the
electric generator is thereby further reduced. The radial bulk of
the electric generator is then the radial bulk of an electric
generator only comprising a single electrical machine.
[0027] Advantageously, the first and second electrical machines are
able to implement different technologies, to reduce the probability
that the electrical machines may simultaneously develop a
fault.
[0028] The invention is described below in a series of variants of
embodiment which can be considered alone or in combination with one
or more of the others.
[0029] Advantageously, the first and second rotors each comprise
first and second walls, arranged either side of the first and
second stators respectively, which define a first and second
annular housing respectively in which the first and second stators
are housed, the second wall of the first rotor and the first wall
of the second rotor being arranged facing one another and the first
azimuthal securing means being configured to join together the
second wall of the first rotor and the first wall of the second
rotor in an azimuthal direction. Azimuthal coupling is therefore
obtained between the first and second rotors.
[0030] It will therefore be understood that in the electrical
machines of the electric generator of the present invention, each
stator is arranged between the first and second walls of the
corresponding rotor, the first and second walls of each of the
rotors defining a circumferential housing. It will also be
understood that the first and second electrical machines are placed
side by side, and that they are secured to one another by
cooperation of their adjacent walls. It is therefore understood
that in a plane containing the first axis the electric generator
has an axis of symmetry positioned between the second wall of the
first machine and the first wall of the second machine.
[0031] With this arrangement, it is sufficient that one of the
electrical machines is driven in rotation about the first axis so
that it will cause the other electrical machine also to be driven
in rotation about the first axis.
[0032] Additionally, with this arrangement, it will be understood
that the structure of the stators need not be modified so that they
can be mounted on the electric generator of the present invention,
thereby avoiding the generation of additional costs for the
manufacture and assembly thereof. Also, it will be understood that
the first securing means are mounted on the outer surface of the
adjacent walls of the first and second rotors, so that the inner
structure of the rotors and the functioning of the electrical
machines are not modified by the joining of the first and second
electrical machines.
[0033] By outer surface of the walls is meant the surface of the
rotor walls opposite the surface arranged facing the first and
second stator with which the first and second rotors respectively
cooperate.
[0034] Preferably the first and second walls of the first and
second rotors are of annular shape.
[0035] Advantageously the first and second walls of the first and
second rotors are in the shape of coaxial discs.
[0036] Preferably the first and second stators are also coaxial
discs.
[0037] Advantageously the first and second stators are coaxial to
the first and second rotors.
[0038] Preferably, the first azimuthal securing means also form
axial securing means configured to couple together the first and
second rotors along the first axis. In other words, they prevent
any axial movement between the first and second rotors. The only
degree of freedom is radial movement which is only permitted during
mounting and dismounting operations of the electric generator of
the present invention.
[0039] Advantageously, the first azimuthal securing means comprise
a sliding connection enabling radial movement of the second wall of
the first rotor relative to the first wall of the second rotor when
assembling the electric generator.
[0040] With this arrangement, it will be understood that the first
and second rotors are secured together via radial translation along
an axis perpendicular to the first axis, so that the axial space
required for assembling of the electric generator is equal to the
axial space taken up the electric generator once it has been
mounted.
[0041] By axial space is to be understood the portion of the first
axis along which the first and second electrical machines are
arranged in the electric generator of the present invention.
[0042] It will therefore be understood that the first azimuthal
securing means are moved radially relative to the first and second
rotors in order to assemble the electric generator of the present
invention. The use of a sliding connection therefore ensures a
maintained constant gap between the first and second rotors
[0043] Preferably the sliding connection comprises an outer slide
formed on one of the walls from among the second wall of the first
rotor and the first wall of the second rotor, and an inner slide
formed on the other of the walls from among the second wall of the
first rotor and the first wall of the second rotor, the inner and
outer slides being configured so that the inner slide slides in the
outer slide at the time of assembling the electric generator.
[0044] It will therefore be understood that the second wall of the
first rotor and the first wall of the second rotor comprise outer
and inner slides formed on their outer surface so that it is
possible to secure the two walls to one another. With this
arrangement, the manufacturing of the rotors is identical to that
of a rotor intended to equip an electric generator only comprising
a single electrical machine, the inner and outer slides simply
having to be added and secured onto the outer surfaces of the
rotors.
[0045] Advantageously, the slide connection has a dovetail-shaped
profile.
[0046] By dovetail is meant a slide connection which comprises a
tenon of trapezoid shape engaging in a groove of same shape to
ensure the sliding connection.
[0047] The sliding of the slides one in the other also provides for
simplified mounting of the electric generator of the present
invention, once the inner slide is engaged in the outer slide, the
user only having to translate the slides in relation to each
other.
[0048] Advantageously, one of the first and second rotors is
composed of at least two sections and of assembly means allowing
the joining of the two sections to each other, the first azimuthal
securing means being arranged on at least one of the sections.
[0049] With this arrangement, it is possible to manufacture and
transport the different sections of the rotor separately, the
assembling together of the sections possibly being performed at the
mounting site of the electric generator of the present
invention.
[0050] Additionally, the use of sections to form the rotor also
allows electrical machines of varying sizes to be produced, and in
particular of large size using one same production tooling.
[0051] Preferably the two rotors are composed of at least two
sections.
[0052] Advantageously, the two rotors comprise the same number of
sections.
[0053] Advantageously, each section of the first rotor can be
secured by azimuthal securing means to one of the sections of the
second rotor.
[0054] Preferably, the electric generator also comprises attachment
means to secure the first and second stators.
[0055] With this configuration, the gap between the stators is kept
constant.
[0056] Advantageously, the electric generator also comprises a
third axial flow electrical machine comprising a third rotor
coaxial to the first rotor and surrounding a third stator to
generate a third magnetic flow, and second azimuthal securing means
to secure the third rotor to one of the first and second rotors so
that the first, second and third rotors can be simultaneously set
in rotation about the first axis to generate the first, second and
third magnetic flows simultaneously.
[0057] The third rotor therefore defines a third annular housing
configured to receive the third stator, the third annular housing
being connected to one of the first and second annular housings by
the second azimuthal securing means.
[0058] It will be understood that all the advantages detailed
previously for an electric generator comprising a first and second
electrical machine remain true for the case in which the electric
generator comprises three electrical machines. It is within easy
reach of persons skilled in the art, from the structure of the
electric generators described in this application, to infer the
structure of an electric generator which may comprise four, five or
more electrical machines. It is therefore easily possible to have
an electric generator of the desired power by associating a
suitable number of electrical machines.
[0059] The invention also concerns a wind turbine comprising a
tower and hub mounted in rotation relative to the tower about an
axis of rotation, the hub being driven in rotation by a spinner,
the wind turbine also comprising an electric generator according to
the present invention, the first and second rotors being mounted in
rotation about the axis of rotation.
[0060] Advantageously, at least one of the first and second rotors
comprises securing means configured to secure the said at least one
of the first and second rotors to the hub.
[0061] With this configuration it will be understood that the
spinner, via the securing means, drives the first and rotors in
rotation. Therefore the electric power produced by the wind turbine
of the present invention, obtained by combining the first and
second electrical machines, is substantially higher than the power
that would be produced by a wind turbine of same size of which the
electric generator only comprises one of the first and second
electrical machines.
[0062] Preferably the wind turbine comprises a flange connecting
the hub to at least one of the electrical machines, perforations
being made in the flange to allow ventilation of the electrical
machines.
[0063] Advantageously, the wind turbine comprises a ventilation
system comprising at least one ventilation module formed of a fan
and motor.
[0064] Preferably, the ventilation system comprises at least as
many ventilation modules as there are electrical machines.
[0065] With this configuration, it will be understood that each of
the ventilation modules is intended to ventilate separately one of
the electrical machines. The configuration of the ventilation
system therefore allows some ventilation modules to be placed in
operation selectively to ventilate at least one of the electrical
machines.
[0066] Advantageously, each electrical machine comprises a power
converter configured to transfer the electric power generated by
the electrical machines onto the electricity grid allowing the
conveying of electric energy to consumers.
[0067] Advantageously, the wind turbine of the present invention
comprises a selection system configured to set in operation
independently each of the power converters of the electric
generator.
[0068] It will therefore be understood that it is possible to
optimise the yield of the electric generator, for example when wind
power is low, by only setting in operation some power converters.
The selection system also allows the production time of electric
energy to be distributed over the different electric machines so as
to manage the wear thereof.
[0069] More generally it will be understood that the electric
generator of the present invention comprises numerous modular
factors: several electrical machines can be combined with one
another within one same electric generator, the different
electrical machines can be of same or different size and power or
have same or different properties, or they can apply same or
different technologies, the rotors can be composed of several
sections, the stators can also be composed of several separate
parts intended to be assembled, the ventilation system comprises
several ventilation modules, each electrical machine is associated
with a separate power converter, . . . .
[0070] It will therefore be understood that starting from
elementary components such as the rotor sections, stator elements,
ventilation modules, power converters, . . . , it is possible to
produce a wind turbine which meets all types of power and size
requirements. As detailed in the foregoing when describing the
electric generator comprising first and second electrical machines,
said modular structure has multiple advantages regarding cost and
complexity of manufacture, the transport of components of the wind
turbine to the assembly site, the dimensions of the assembled wind
turbine, the maintenance thereof, its capacity to generate electric
energy continuously, despite unfavourable outside conditions or
faulty elements, . . . .
[0071] In addition, the invention also concerns a method for
mounting a wind turbine according to the present invention, the
wind turbine comprising a first and second electrical machine, the
method comprising a step during which the first electrical machine
is mounted on the wind turbine, followed by a step during which the
second stator is mounted on the wind turbine, followed by a step
during which the second rotor is mounted around the second stator
and is secured to the first rotor.
[0072] Advantageously, it is therefore possible to replace one of
the constituent elements of one of the first and second machines
without dismounting the assembly formed by the first and second
electrical machines.
[0073] Advantageously, the first and second electrical machines can
be mounted together in accordance with the method, before the
assembly formed by the first and second electrical machines is
mounted on the wind turbine, for example to carry out testing
thereof.
[0074] Finally, the invention concerns a method for assembling a
wind turbine of the present invention, the wind turbine comprising
a first, a second and a third electrical machine, the method
comprising a step during which the first electrical machine is
mounted on the wind turbine, followed by a step during which the
second stator is mounted on the wind turbine, followed by a step
during which the third electrical machine is mounted on the wind
turbine, followed by a step during which the second rotor is
mounted around the second stator and is secured to the first and
third rotors.
[0075] Advantageously the first, second and third electrical
machines can be mounted together according to the method before the
assembly formed by the three electrical machines is mounted on the
wind turbine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0076] Other characteristics and advantages of the invention will
become more clearly apparent and complete on reading the following
description of one preferred embodiment given as a non-limiting
example and with reference to the appended drawings in which:
[0077] FIG. 1 schematically illustrates an example of an electric
generator according to the present invention, the electric
generator comprising a first and second electrical machine;
[0078] FIG. 2 schematically illustrates the first and second
electrical machines of the electric generator in FIG. 1, seen from
overhead;
[0079] FIG. 3 schematically illustrates part of the first and
second electrical machines of the electric generator in FIG. 1;
[0080] FIG. 4 schematically illustrates part of the first and
second electrical machines of the electric generator in FIG. 1;
[0081] FIG. 5 schematically illustrates a step in the mounting of
the electric generator in FIG. 1;
[0082] FIG. 6 schematically illustrates a wind turbine comprising
the electric generator in FIG. 1; and
[0083] FIG. 7 schematically illustrates an example of an electric
generator according to the invention, the electric generator
comprising a first, a second and a third electrical machine.
DETAILED DESCRIPTION OF THE INVENTION
[0084] In the example illustrated in FIG. 1, the electric generator
10 of the invention has a first axial flow electrical machine 100
formed by a first rotor 102 mounted in rotation about a first axis
X and surrounding a first stator 104. The electric generator 10
also has a second axial flow electrical machine 200 formed by a
second rotor 202 also mounted in rotation about a first axis X and
surrounding a second stator 204.
[0085] As illustrated in FIG. 1, the first rotor 102 has a U-shaped
profile, but is not limited thereto; the first rotor 102
particularly comprises first 106 and second 108 walls arranged
either side of the first stator 104. The first rotor 102 further
comprises a first upper edge 110 which connects the first 106 and
second 108 walls.
[0086] The first 106 and second 108 walls of the first rotor 102
each have an annular shape and define a first annular housing
configured to receive the first stator 104.
[0087] It will therefore be understood that the first rotor 102
surrounds the first stator 104 circumferentially. In other words,
the first rotor 102 extends along the circumference of the first
stator 104 so as to surround the latter.
[0088] Similarly the second rotor 202 has a U-shaped profile but is
not limited thereto; the second rotor 202 in particular comprises
first 206 and second 208 walls arranged either side of the second
stator 204 and connected by a second upper edge 210.
[0089] Therefore, in similar manner to the first electrical machine
100, the first 206 and second 208 walls of the second rotor 202 are
each of annular shape, and define a second annular housing
configured to receive the second stator 204.
[0090] In other words, second rotor 202 surrounds the second stator
204 circumferentially.
[0091] Without departing from the scope of the present invention,
the first and second walls 106, 108, 206, 208 and the upper edges
110, 210 of each of the first and second rotors 102, 202 could form
a single part having a profile such that it surrounds the first 104
and second 204 stators respectively.
[0092] The electric generator 10 of the present invention also
comprises first securing means 12 arranged between the second wall
108 of the first electrical machine 100 and the first wall 206 of
the second electrical machine 200, which will be described in more
detail in particular in the description of FIG. 2.
[0093] It will be understood that the first securing means 12 are
configured to join the first and second circumferential housings
defined by the first 102 and second 202 rotors respectively.
[0094] The electric generator 10 also comprises first connecting
means 14 arranged between the first 100 and second 200 electrical
machines. As illustrated in FIG. 1, the upper end 15 of the first
connecting means 14 is arranged between the first 104 and second
204 stators and comprises attaching means 16 configured to secure
the first 104 and second 204 stators.
[0095] The median portion of the first connecting means 14
comprises a perforation 18, and the lower portion thereof 20
comprises first 22 and second 24 attaching elements.
[0096] As illustrated in FIG. 1, the electric generator 10 also
comprises first 26 and second 28 bearings. The upper portion of the
first bearing 26 is secured to the second wall 108 of the first
rotor 102 of the first electrical machine 100 via first securing
means 29; the lower portion of the first bearing 26 is secured to
the upper end 15 of the first connecting means 14 via second
securing means 30.
[0097] The upper portion of the second bearing 28 is secured to the
lower end 20 of the first connecting means 14 via second attaching
elements 24; the lower portion of the second bearing 28 comprises
coupling means 31.
[0098] As illustrated in the different Figures, the first and
second 29, 30 securing means, the first and second 22, 24 attaching
elements and the coupling means 31 can be formed of bolts; they may
also be formed of any other means allowing the securing together of
several elements without departing from the scope of the
invention.
[0099] Finally, the electric generator 10 comprises attaching means
33 mounted both on the first wall 106 of the first rotor 102 of the
first electrical machine 100 and on the second bearing 28 via
coupling means 31.
[0100] FIG. 2 gives a detailed illustration of the first azimuthal
securing means 12.
[0101] In this Figure in which the first 102 and second 202 rotors
are illustrated from above, it can be seen that the first azimuthal
securing means 12 are formed of an outer slide 32 and inner slide
34.
[0102] The outer slide 32 is formed by first 36 and second 38
lateral portions, both formed on the first wall 206 of the second
rotor 202. The space formed between the first 36 and second 38
lateral portions defines a housing having a trapezoid-shaped
profile.
[0103] The inner slide 34 is formed by a first 40 and second 42
side, both formed on the second wall 108 of the first rotor 102 and
which define a section of trapezoid shape configured to be
contained in the housing defined by the outer slide 32. The inner
slide 34 could also be formed of a single part defining a section
of trapezoid shape without departing from the scope of the
invention. It will therefore be understood that the shape of the
inner 34 and outer 32 slides is such that the inner slide 34 is
able to slide in the outer slide 32 in longitudinal direction L,
the longitudinal direction L being defined by the lateral portions
36, 38 and the sides 40, 42 parallel to one another.
[0104] As can be seen in FIG. 2, the lateral portions 36, 38 and
the sides 40, 42 project from the first wall 206 of the second
rotor 202 and the second wall 108 of the first rotor 102
respectively; for example but not limited thereto the lateral
portions 36, 38 and the sides 40, 42 are secured by screwing or any
other securing device onto the first wall 206 of the second rotor
202 and onto the second wall 108 of the first rotor 102.
[0105] It can therefore be seen that the first azimuthal securing
means 12 have a dovetail-shaped profile.
[0106] It could also be contemplated, without departing from the
scope of the present invention, that the first azimuthal securing
means 12 could have a profile of different shape, or that the
electric generator 10 could have an inner slide 34 and outer slide
32 respectively formed on the first wall 206 of the second rotor
202 and on the second wall 108 of the first rotor 102.
[0107] It will therefore be understood that the first azimuthal
securing means 12 comprise a slide connection in a longitudinal
direction L, which forms a radial direction of the first 102 and
second 202 rotors, the slide connection being formed by the inner
slide 34 and outer slide 32 configured to slide in one another when
mounting the electric generator 10 of the present invention, so as
to secure the first 102 and second 202 rotors.
[0108] FIGS. 3 and 4 illustrate part of the first 100 and second
200 electrical machine of the electric generator 10 of the present
invention.
[0109] As illustrated in FIG. 3, the first rotor 102 is formed of
several sections 112, 112' which comprise assembly orifices 114,
114' formed on the upper edges 110, 110' for assembling of the
sections 112, 112', via assembly means such as screws, but not
limited thereto, passed through the assembly orifices 114, 114'.
Any other assembly means could also be envisaged without departing
from the scope of the present invention.
[0110] The first and second walls 106, 108 of the first rotor 102
each define an inner surface and outer surface, the inner surfaces
of the first and second walls 106, 108 being arranged facing one
another and surrounding the first stator 104. As illustrated in
FIG. 3, magnetizing areas 116 are arranged on the inner surfaces of
the walls 106, 108, these magnetizing areas 116 forming the
inductor portion of the magnetic circuit of the first electrical
machine 100.
[0111] For example, but not limited thereto, the magnetizing areas
116 are formed by the superimposition of permanent magnets. It
could also be envisaged without departing from the scope of the
present invention, that the inductor portion of the magnetic
circuit of the first electrical machine 100 is formed of any other
element such as coils for example.
[0112] As illustrated in FIG. 3, the first 40 and second 42 sides
of the inner slide 34 are formed on the outer surface of the second
wall 108. Also, first matching means 118 are arranged on the outer
surface of the second wall 108.
[0113] The first stator 104 is formed by a first rim of which one
portion 120 is illustrated in FIG. 3; the portion 120 comprises
radial notches 122 in which first active modules are inserted
124.
[0114] The first active modules 124 form the induced part of the
magnetic circuit of the first electrical machine 100.
[0115] It will therefore be understood from FIG. 3, that the first
rim of the first stator 104 is advantageously formed of at least
two portions 120, the portions 120 able to be easily assembled at
the mounting site of the electric generator 10 using conventional
operations for those skilled in the art such as welding or riveting
for example.
[0116] It will also be understood that the shape of the sections
112, 112' of the first rotor 102 makes it possible easily and
precisely to position the inducing part in relation to the induced
part of the first stator 104.
[0117] Finally it will be understood that the assembling of the
portions 120 of the first rim of the first stator 104 defines a
disc the centre of which has an orifice for mounting of the first
stator 104 in free rotation. The assembling of the sections 112,
112' of the first rotor 102 defines a cylinder portion having an
outer diameter of same or even slightly larger size than the disc
formed by the first stator 104, the cylinder portion formed by the
first rotor 102 comprising two lateral edges arranged perpendicular
to the cylinder surface and configured to be arranged either side
of the radial end of the disc formed by the first stator 104.
[0118] Similarly, and as illustrated in FIG. 4, the second rotor
202 is formed of several sections 212, 212' comprising assembly
orifices 214, 214'. The first and second walls 206, 208 each
comprise an inner surface and an outer surface, magnetization areas
216 being arranged on the inner surfaces of the walls 206, 208.
[0119] As illustrated in FIG. 4, the first 36 and second 38 lateral
portions of the outer slide 32 are formed on the outer surface of
the first wall 206. In addition, second matching means 218 are
arranged on the outer surface of the first wall 206.
[0120] The second stator 204 is formed of a second rim, of which
one portion 220 is illustrated in FIG. 4; the portion 220 comprises
second radial notches 222 in which second active modules 224 are
inserted.
[0121] It will be understood from FIGS. 3 and 4 that the sides 40,
42 and the lateral portions 36, 38 are respectively arranged
symmetrically in relation to a first R1 and second R2 radius of the
first 102 and second 202 rotors.
[0122] FIG. 5 illustrates a mounting step of the electric generator
10.
[0123] Initially the first connecting means 14 are mounted on the
second bearing 28, via cooperation between second attaching
elements 24 and the upper part of the second bearing 28.
[0124] The portions 120 of the first rim of the first stator 104
are then mounted on the upper end 15 of the first connecting means
14, and the first bearing 26 is also mounted, for example but not
limited thereto by welding or riveting, on the upper end 15 of the
first connecting means 14.
[0125] As detailed previously in connection with FIG. 3, the
sections 112, 112' of the first rotor 102 are then mounted around
the first stator 104, the sections 112, 112' being secured via
their assembly orifices 114, 114' and assembly means, and the
radial engaging of the sections 112, 112' around the first stator
104 is limited by the presence of the first bearing 26; in
particular, the first securing means 29 allow the securing together
of the second wall 108 of the first rotor 102 and the first bearing
26.
[0126] Next, the portions 220 of the second rim of the second
stator 204 are mounted on the attaching means 16 of the upper end
15 of the connecting means 14. In particular, the attaching means
16 define a first and second longitudinal end, the first and second
stators 104, 204 being respectively mounted on each of the
longitudinal ends, the first bearing 26 being mounted between the
two longitudinal ends.
[0127] Thereafter and as illustrated in FIG. 5, the sections 212,
212' of the second rotor 202 are moved radially relative to the
sections 112, 112' of the first rotor 102.
[0128] For example, but not limited thereto, the first and second
rotors 102, 202 each comprise the same number of sections, each
section 112, 112', 212, 212' comprising first azimuthal securing
means 12 and each section 112, 112' of the first rotor 102 being
configured to cooperate with a section 212, 212' of the second
rotor 202.
[0129] It could also be contemplated, without departing from the
scope of the invention, that the first 102 and second 202 rotors do
not comprise the same number of sections or that the matching of
the sections of the first and second rotors 102, 202 is only
performed by some of their sections.
[0130] It will therefore be understood, as illustrated in
particular in FIG. 5, that the section 220 of the second rotor 202
is arranged above the second stator 204, the first and second walls
206, 208 being arranged on each side of the second stator 204, and
the first wall 206 of the second rotor 202 is arranged facing the
second wall 108 of the first rotor 102, the lower end 37 of the
outer slide 32 formed on the second rotor 202 being arranged
opposite, even slightly above the upper end 39 of the inner slide
34 formed on the first rotor 102. The second rotor 202 can then be
moved radially relative to the first rotor 102, when mounting or
dismounting the electric generator 10, so that the outer slide 32
slides around the inner slide 34. In this position in which the
outer 32 and inner 34 slides cooperate, there is merging of the
first R1 and second R2 radii.
[0131] The second rotor 202 is therefore moved radially in relation
to the first rotor 102 until the first 118 and second 218 matching
means are arranged opposite one another to match the first 102 and
second 202 rotors. For example and not limited thereto, the
matching means 118, 218 can be formed by threaded holes and bolts,
rivets or any other device allowing the matching of the first and
second 102, 202 rotors. It could also be envisaged, without
departing from the scope of the present invention, that there is an
abutment on the first azimuthal securing means 12 allowing the
limiting of radial movement of the second wall 108 of the first
rotor 102 relative to the first wall 206 of the second rotor
202.
[0132] It will therefore be understood that the first azimuthal
securing means 12 have the effect that the first 102 and second 202
rotors are unable to rotate in relation to one another about the
first axis X.
[0133] It will also be understood that the shape of the first
azimuthal securing means 12, described in particular with reference
to FIG. 2, is such that the first azimuthal securing means 12
prevent any axial movement relative to the first axis X between the
first 102 and second 202 rotors, thereby making it possible to
maintain constant the distance separating the first 102 and second
202 rotors. It therefore appears that the first azimuthal securing
means 12 also form axial securing means.
[0134] Without departing from the scope of the present invention,
an electric generator 10 can also be envisaged of which the second
rotor 202 is secured onto the first bearing 26, the second rotor
202 therefore not necessarily comprising matching means to allow
the second rotor 202 to be matched directly with the first rotor
102.
[0135] FIG. 6 illustrates a wind turbine 50 comprising a hub 52
mounted in rotation about the first axis X, and a spinner 54 to
drive the hub 52 in rotation about the first axis X; also, the
first 100 and second 200 electrical machines are mounted in the
wind turbine 50. As illustrated in FIG. 6, the first and second
stators 104, 204 and the first and second rotors 102, 202 are
coaxial to one another, the first and second 102, 202 rotors both
being mounted in rotation about the first axis X.
[0136] The attaching means 33 mounted on the first wall 106 of the
first rotor 102 are also mounted on the hub 52. It will therefore
be understood that when the spinner 54 drives the hub 52 in
rotation about the first axis X, it also drives the first rotor 102
in rotation about the first axis X, via the attaching means 33.
Subsequently, since the first and second rotors 102, 202 are
secured by the first azimuthal securing means 12, the second rotor
202 is simultaneously driven in rotation about the first axis
X.
[0137] For example but not limited thereto the attaching means 33
are formed of a plate or metal sheet of which the lower and is
attached to the hub 52 and to the second bearing 28, for example by
clamping the lower end of the metal sheet between the hub 52 and
the second bearing 28.
[0138] As can be seen on examining FIG. 6, the wind turbine 50 is
also formed of a frame 55 secured to a tower 57 on which the hub 52
is mounted in rotation. The first and second stators 104, 204 are
mounted firstly on the frame 55 of the wind turbine via first
attaching elements 22 mounted on the lower end 20 of the first
connecting means 14, and secondly on the first and second bearings
26, 28; they are not driven in rotation about the axis X. Therefore
via respective cooperation between the induced part of the first
and second stators 104, 204 stators and the inducing part of the
first and second rotors 102, 202, the first and second electrical
machines 100, 200 respectively generate first and second magnetic
flows.
[0139] As illustrated in FIG. 6, the wind turbine 50 also comprises
a ventilation system 56 which comprises at least one ventilation
module 58 formed of a fan and motor. The ventilation system 56 also
comprises an aeration duct 60 directed towards the perforation 18
formed in the median portion of the first connecting means 14.
[0140] Therefore and as shown by the arrows illustrating the cycle
in FIG. 6, the ventilation system 56 allows the diffusing of a
fluid e.g. air of temperature T1 in the first and second electrical
machines 100, 200. The operation of the first and second electrical
machines 100, 200 and in particular the rotation of the first 102
and second 202 rotors, tends to raise the temperature of the fluid
which is then directed at temperature T2, towards the ventilation
system 56. Through heat exchange with the environment outside the
wind turbine 50, the temperature of the fluid is lowered to
temperature T1, before the fluid is again directed into the
aeration duct 60 towards the first and second electrical machines
100, 200.
[0141] As detailed in particular with reference to FIGS. 3 and 4,
the first 100 and second 200 electrical machines have a modular
structure and in particular comprise several sections 112, 112',
212, 212' forming the first 102 and second 202 rotors, and several
portions 120, 220 forming the rims of the first 104 and second 204
stators. The first connecting means 14 subsequently define a
circular shape coaxial with the stators 104, 204 and may also, but
not limited thereto, be formed of a plurality of elements arranged
between the first 100 and second 200 electrical machines. It will
also be understood that the perforations 18 formed in the median
part of the first connecting means 14 are not necessarily
distributed homogeneously over the entire circular shape defined by
the first connecting means 14. For example and not limited thereto,
at some positions of the circular shape defined by the first
connecting means 14, the median portion may not be perforated.
Therefore the ventilation system 56 allows the ventilation of the
first 100 and second 200 electrical machines, the perforations 18
formed in the first connecting means 14 directing the fluid towards
the first machine 100, whereas the positions of the circular shape
defined by the first connecting means 14 in which no perforation is
formed direct the fluid towards the second electrical machine
200.
[0142] In addition, the ventilation system 56 may be formed of
several ventilation modules 58. For example and not limited
thereto, to allow homogenous ventilation of the electrical machines
100, 200, the same number of ventilation modules 58 may be intended
for the ventilation of the first 100 and second 200 electrical
machines.
[0143] It will therefore be understood that the first connecting
means 14 indirectly connect the hub 52 to the first and second
electrical machines, 100, 200 and form a flange in which
perforations 18 are made to allow ventilation of the electrical
machines 100, 200.
[0144] As detailed in the foregoing, the first and second rotors
102, 202 and the first and second stators 104, 204 are respectively
formed of permanent magnets arranged around active modules. It will
also be understood that the structure of the first and second
electrical machines 100, 200 of the present invention is identical.
Nevertheless, it could just as well be envisaged without departing
from the scope of the invention that in the electric generator 10
either one of the first and second electrical machines 100, 200, or
both, has induced and inducing parts of different structure; for
example and not limited thereto one of the electrical machines 100,
200 could comprise a coiled rotor.
[0145] FIG. 7 illustrates another embodiment of the electric
generator 10 according to the present invention which, in addition
to the first and second electrical machines 100, 200, comprises a
third electrical machine 300 formed by a third rotor 302 coaxial to
the first rotor 102 and surrounding a third stator 304. In
addition, the electric generator 10 also comprises a third bearing
62 and second connecting means 66.
[0146] Similar to the first 100 and second 200 electrical machines
previously described, the third rotor 302 of the third electrical
machine 300 comprises first 306 and second 308 walls both of
annular shape, which define a third annular housing configured to
receive the third stator 304. The third stator 304 is therefore
surrounded by the third rotor 302 circumferentially.
[0147] As illustrated in FIG. 7, the first 100 and third 300
electrical machines are arranged symmetrically either side of the
second electrical machine 200.
[0148] It will be understood that to mount the electric generator
10 such as illustrated in FIG. 7, in similar manner to the mounting
previously described, the first electrical machine 100 and the
second stator 204 are mounted on the first connecting means 14. The
second connecting means 66 are then mounted on the second stator
204, the lower end of the second connecting means 66 being attached
to the frame 55. The third electrical machine 300 is then mounted
on the second connecting means 66, the first wall 306 of the third
rotor 302 being mounted on the third bearing 62, whilst the third
stator 304 is mounted on the upper end of the second connecting
means 66.
[0149] The second rotor 202 is then engaged between the first 100
and third 300 electrical machine, second azimuthal securing means
68 being formed on the second wall 208 of the second electrical
machine 200 and on the first wall 306 of the third electrical
machine 300.
[0150] It will therefore be understood that the second azimuthal
securing means 68 are configured to join together the second and
third annular housings defined by the second 202 and third 302
rotors respectively.
[0151] Therefore, and in similar manner to the foregoing
description with reference in particular to FIG. 6, the spinner 54
drives the hub 52 in rotation about a first axis X, so that the
first rotor 102 rotor is driven in rotation about the first axis X
via attaching means 33. Subsequently, the second 202 and third 302
rotors being secured to the first rotor 102 by the first 12 and
second 68 azimuthal securing means, they are simultaneously driven
in rotation about the first axis X. Since the first 104, second 204
and third 304 stators are not driven in rotation about the first
axis X, through respective cooperation between the induced part of
the first, second and third stators 104, 204, 304 and the inducing
part of the first, second and third rotors 102, 202, 302, the
first, second and third electrical machines 100, 200, 300 machines
respectively generate a first, second and third magnetic flow.
[0152] The foregoing detailed characteristics regarding the
structure of the first and second electrical machines 100, 200
evidently apply to the third electrical machine 300. In particular,
perforations can be made in the second connecting means 66 to
enable the ventilation system 56 to ventilate the first, second and
third electrical machines 100, 200, 300.
[0153] The entire foregoing description is given as an example and
therefore does not limit the invention.
[0154] In particular, although the invention is particularly
detailed for electric generators comprising two or three electrical
machines, it can be extended directly and obviously to a higher
number of electrical machines.
* * * * *