DK202200086U3 - Counter-rotating wind turbine and wind power plant comprising a counter-rotating wind turbine - Google Patents

Abstract

A wind turbine (12) is presented comprising at least a first turbine rotor (16) and a second turbine rotor (23), where the first turbine rotor (16) and the second turbine rotor (23) rotate around the same axis of rotation (A) and are counter-rotating. The wind turbine (12) further comprises a generator (35) comprising a first generator part (36) and a second generator part (38), where the first generator part (36) is mounted on the first turbine rotor (16) so that it faces the second turbine rotor (23), and the second generator part (38) is mounted on the second turbine rotor (23) so that it faces the first turbine rotor (16). The first generator part (36) comprises at least one generator magnet and the second generator part (38) comprises at least one generator coil for generating an electric current when the wind turbine (12) is in operation.

Description

l DK 202200086 U3

Counter-rotating wind turbine and wind power plant comprising a counter-rotating wind turbine

The present invention relates to a wind turbine with an axis of rotation substantially perpendicular to the direction of the wind and usually arranged with a vertical axis of rotation and a wind power plant comprising such a wind turbine.

Today, wind power accounts for approx. 8-10% of the annual installed power capacity globally (approx. 750 GW). Wind will play an increasingly important role in the ongoing energy transition to renewable energy. Global cumulative installed capacity of onshore wind power is projected to more than triple by 2030 to 2,000

GW and may increase sevenfold by 2050 to 5,000 GW, and it is expected that the installed wind power capacity will further increase globally towards 2050.

There are two main wind turbine technologies, classified according to the orientation of the wind turbine's axis of rotation. Three-bladed horizontal axis wind turbines (HAWT) with the blades downwind of the tower produce the overwhelming majority of — wind power in the world today. These turbines have the main rotor shaft and electric generator at the top of a tower and are pointed into the wind. The generator is placed on top of a shaft in a nacelle. The technology for such wind turbines is mature, and all horizontal turbines produced and installed today are of similar design. The HAWTs have grown in size and installed capacity in recent years and now range from IMW to 14MW per turbine.

A vertical axis wind turbine (VAWT), on the other hand, has its axis of rotation perpendicular to the direction of the wind and is typically installed with a vertical axis of rotation relative to the ground surface. This is therefore a type of wind turbine where the main rotor shaft is set across the wind, while the main components can be found at the foot of the turbine. This arrangement allows the generator to be located close to the ground, with a low center of gravity, allowing easy access for service and repair. VAWTs do not need to be pointed into the wind, eliminating the need for wind sensing and orientation mechanisms. However, VAWTs have not received the same attention and investment as HAWTs and today account for less than 0.1% of the installed wind power capacity.

Existing technology regarding VAWTs has certain drawbacks which may explain the very low attention that VAWTs have received so far. First, the efficiency of traditional Savonius VAWT turbines is lower compared to

HAWTs as it is mainly a turbine that relies on draft for its operation and the upwind blades do not contribute to power generation. The smaller Darius turbines are also subject to vibration from the torque exerted on the mast, leading to increased wear and need for maintenance. And finally, and perhaps most importantly, VAWTs have received nowhere near the same amount in

, DK 202200086 U3 investments in research and development as HAWTs and is therefore a much less mature technology.

In general, a problem with existing wind turbines is the gear system, which is exposed to large and varying forces. The gear systems must therefore be designed so that they can — withstand large and varying forces over time and are therefore expensive. The wind turbines still require extensive maintenance and monitoring to prevent and avoid complete breakdown of the gears.

Weather conditions are often violent in places where wind turbines are installed, and the design of the wind turbines must compensate for the effect of strong winds and also waves for wind turbines installed offshore. Furthermore, wind conditions can vary considerably depending on how far from the ground or water surface the wind turbine is mounted.

Thus, an aim of the present invention has been to develop a wind turbine in which at least one and preferably some or all of the above problems are mitigated.

A further purpose of the present invention has been to provide a wind turbine in which the production costs, maintenance and monitoring of the gear system for wind turbines are reduced.

A further purpose of the present invention has been to provide a wind turbine that can be combined with and/or integrated with other structures to be erected.

A further purpose of the present invention has been to provide a wind turbine which is suitable for retrofitting on an existing construction.

A further purpose of the present invention has been to develop a wind turbine which takes into account the varying wind conditions at the ground or water surface and at a certain distance from the ground or water surface.

A further object of the present invention has been to develop a wind turbine with a generator that does not need a gear system.

A further purpose of the present invention has been to develop a wind turbine with effective cooling of the generator.

A further object of the present invention has been a wind turbine with a simplified construction compared to ordinary HAWT wind turbines.

2 DK 202200086 U3

These objects are achieved with a wind turbine as defined in claim 1, a wind power plant as defined in claim 22 and use of the wind turbine or the wind power plant as defined in claim 29. Further embodiments of the wind turbine are defined in the independent claims.

A wind turbine comprising at least a first turbine rotor and a second turbine rotor is thus provided, where the first turbine rotor and the second turbine rotor rotate around the same axis of rotation (A) which extends in the longitudinal direction of the wind turbine, and the first turbine rotor and the second turbine rotor are counter-rotating. The wind turbine further comprises a generator comprising a first generator part and a second generator part, where the first generator part is mounted on the first turbine rotor and the second generator part is mounted on the second turbine rotor, and where the first generator part comprises at least one generator magnet, and the second generator part comprises at least one generator coil for generating an electric current when the wind turbine is in operation, i.e. when the first — turbine rotor and/or the second turbine rotor rotates.

The present wind turbine is thus preferably a VAWT, i.e. the axis of rotation of the wind turbine is placed at an angle of approximately 90 degrees to the direction of the wind, and usually as a vertical wind turbine, although it is possible to place the wind turbine so that the axis of rotation is horizontal and at the same time essentially perpendicular to the direction of the wind. It should be noted that the generator magnet can be a permanent magnet or an electromagnet. It should also be mentioned that the axis of rotation

A and the longitudinal direction of the wind turbine and the tower can be arranged so that they are slightly inclined in relation to a horizontal plane. This may be suitable for, for example, floating wind turbines placed in water. — An advantage of the present turbine compared to conventional turbines normally installed today is that the counter-rotating turbines do not produce torques that must be lifted by a supporting structure, such as the tower of the wind farm. The present wind turbine is therefore suitable for retrofitting on an existing structure such as the tower of existing wind turbines with a horizontal axis. Existing wind power plants can therefore be easily upgraded and made more efficient.

A further advantage of the wind turbine described here is that there is no need for a gear. This results in less friction loss and cooling requirements. The absence of gears also makes the present wind turbine much more reliable and requires less maintenance compared to the traditional horizontal axis turbines commonly built today. This makes the present wind turbine more suitable for use in places where the weather conditions are harsh, such as offshore places. Furthermore, since the wind turbine does not require a gear system, it is also easier to scale up the existing wind turbine than traditional wind turbines.

The first generator part is preferably mounted on a radially peripheral first part of the first turbine rotor which faces the second turbine rotor, and the second generator part is preferably mounted on a radially peripheral second part of the second turbine rotor which faces the first turbine rotor. By arranging the generator on the periphery of the turbine rotors, there is less need for cooling, as the parts of the generator will have a large surface which is naturally cooled by air.

The first turbine rotor may comprise an upper first turbine rotor and a lower first turbine rotor, which are placed on opposite sides of the second turbine rotor in the longitudinal direction of the wind turbine.

The upper first turbine rotor and the lower first turbine rotor are preferably mounted on a first turbine shaft, i.e. a common shaft for the two turbine rotors which is adapted to be rotatably mounted on a tower of a wind turbine or to a fixture of a separate structure. For example, the wind turbine can be retrofitted to a tower of an existing wind power plant, or at the same time as a separate wind power plant is built. The second turbine rotor, on the other hand, is preferably rotatably mounted on the first turbine shaft.

The upper first turbine rotor and the lower first turbine rotor are mounted on a first turbine shaft adapted to be rotatably mounted on a tower (13) of a wind turbine (10) or a fastening element (54) on a separate structure

The upper first turbine rotor and the lower first turbine rotor may have equal longitudinal lengths. Alternatively, the upper first turbine rotor and the lower first turbine rotor are made with different lengths in the longitudinal direction, for example due to varying wind intensity at different heights above the ground where the wind farm is located.

The upper first turbine rotor and the lower first turbine rotor may have similar diameters.

Alternatively, the upper first turbine rotor and the lower first turbine rotor have different diameters, for example due to varying wind intensity at different heights above the ground where the wind farm is located.

Likewise, if the wind turbine is provided with a lower first turbine rotor and an upper first turbine rotor, the lower first turbine rotor may have a smaller diameter and/or a smaller height than the upper first turbine rotor, e.g. due to varying wind intensity at different heights above ground level where the wind farm is located. > If the wind turbine is provided with a lower first turbine rotor and an upper first turbine rotor, the first generator part is preferably mounted on a radially peripheral

. DK 202200086 U3 first part of the upper first turbine rotor, which faces the second turbine rotor, and the second generator part is preferably mounted on a radially peripheral second part of the second turbine rotor, which faces the first turbine rotor. Alternatively, the first generator part can be mounted on a radially peripheral first part of the first lower turbine rotor facing the second turbine rotor, and the second generator part can be mounted on a radially peripheral second part of the second turbine rotor facing the first turbine rotor.

The wind turbine may further comprise an outer second turbine rotor which is arranged radially outside the first turbine rotor and is securely attached to the second turbine rotor, for example with support elements such as beams, struts, braces or similar elements suitable for supporting the outer second turbine rotor. Thus, the outer second turbine rotor rotates together with the second turbine rotor.

Although not shown in the figures, it should also be mentioned that an outer second turbine can, in the same way, be attached to the second turbine rotor of the embodiment of the wind turbine shown in Figure 3, such that the outer second turbine rotor is located radially outside the upper first turbine rotor.

The first turbine rotor and the outer second turbine rotor preferably have substantially the same length in the longitudinal direction of the wind turbine.

If the wind turbine is provided with an outer second turbine rotor, the first generator part is preferably mounted on a radially peripheral first part of the first turbine rotor which faces the second turbine rotor, and the second generator part is preferably mounted on a radially peripheral second part of the second turbine rotor, which faces the first turbine rotor. Alternatively, the first generator part may — be mounted on a radially peripheral first part of the first turbine rotor facing the outer second turbine rotor, and the second generator part may be mounted on a radially peripheral second part of the outer second turbine rotor facing the first turbine rotor .

Each turbine rotor preferably comprises at least one support arm that extends in an essentially radial direction relative to the wind turbine's axis of rotation, and preferably at least one turbine blade that is mounted on the support arm.

The at least one turbine blade is preferably rotatably mounted on the at least one support arm. The position of the at least one turbine blade in relation to the at least one support arm can thereby be adjusted when the wind turbine, and the at least one support arm, rotate around the axis of rotation of the wind turbine.

The at least one turbine blade preferably extends in a direction that is essentially parallel to the axis of rotation of the wind turbine. The at least one turbine blade therefore extends essentially in the same direction as the axis of rotation of the wind turbine and the longitudinal direction of the wind turbine.

The at least one support arm can comprise a first support arm and a second support arm which are distributed in the longitudinal direction of the wind turbine, and the at least one turbine blade can be rotatably mounted on the first support arm and on the second support arm. The at least one turbine blade can therefore be supported at both ends in the longitudinal direction.

Each turbine rotor of the wind turbine preferably consists of a plurality of support arms, and preferably at least one turbine blade is mounted on each support arm.

The plurality of support arms are preferably evenly distributed circumferentially in relation to the axis of rotation of the wind turbine.

Each support arm may also be provided with an outer support arm which is pivotally connected to the support arm at a radially outer part of the support arm. The outer support arms preferably rotate in relation to their respective support arms when the wind turbine rotates around the axis of rotation of the wind turbine, so that the outer support arms at all times have a desired position in relation to their respective support arms depending on the wind direction, i.e. the rotational position of their respective support arms 1 the circumferential direction around the axis of rotation of the wind turbine.

The at least one turbine blade is preferably mounted on each outer support arm.

Furthermore, at least one turbine blade can be rotatably mounted on the outer support arm, — and/or at least one turbine blade can be rotatably mounted on the support arm.

Alternatively, a plurality of turbine blades can be rotatably mounted on each support arm and/or the outer support arm, where the turbine blades are distributed in a radial direction relative to the wind turbine's axis of rotation along the length of the support arm and/or the outer support arm.

The outer support arm is preferably arranged to be actively rotated relative to the support arm, as the turbine rotors rotate around the wind turbine's axis of rotation.

Furthermore, each support arm is preferably provided with an actuating means that rotates the outer support arm to a desired position relative to the support arm.

The actuating means is preferably a motor, such as an electric motor, a hydraulic motor or a pneumatic motor of a type commercially available and suitable for effecting the rotational movement of the outer arms relative to their respective support arms as the turbine rotors rotate around the wind turbine axis of rotation.

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The wind turbine preferably comprises a control system that controls the drive devices of the support arm so that each outer arm is rotated to a desired position in relation to the support arm to which it is rotatably attached, depending on the rotational position of the support arm when the turbine rotors rotate around the wind turbine's axis of rotation.

Alternatively, the wind turbine may be provided with chains, belts, a gear system, a combination of these or any other similar device which can control the position of the outer arms in relation to the respective support arms on which they are mounted, and the longer the position of the turbine blades in relative to — the support arms and/or the outer support arms they are mounted on while the turbine rotors of the wind turbine are rotating.

The wind turbine may further incorporate spring elements to facilitate the movement of the outer support arms relative to the support arms and/or the movement of the turbine blades relative to the outer support arms and/or support arms, and/or to — help recover at least some of the energy used to affect the rotational movement of the outer support arms relative to their respective support arms when the outer support arms rotate between a first extreme position and a second extreme position relative to the support arm arm, i.e. an imaginary line through or imaginary extension of the support arm when the wind turbine rotates around the axis of rotation A during operation of the wind turbine.

The wind turbine can be rotatably mounted on a separate structure, such as a tower structure. The longitudinal direction of the tower structure is preferably substantially parallel to the axis of rotation of the wind turbine, i.e. the wind turbine is typically a vertical axis wind turbine once the wind turbine has been installed.

A wind power plant is also provided comprising a separate structure and a wind turbine as described above, where the wind turbine is mounted on the separate structure.

The separate structure can be an existing structure, ie. the wind turbine is retrofitted to an existing construction. Alternatively, the separate — construction can be a construction under construction, i.e. the wind turbine is mounted on the separate structure while it is being constructed, and the wind turbine can therefore be integrated with the separate structure during the design phase.

The separate construction may, for example, be a tower of an existing wind farm or a wind farm under construction.

The separate structure can also be a mast, such as a radio mast or a TV mast or an electricity mast or a mobile mast.

The separate structure can also be a pole, such as a lamppost or a telegraph pole.

The separate construction can also be a chimney.

Also provided is a method for using a wind turbine as described above and/or a wind power plant as described above, in which the wind turbine is mounted on a separate structure.

The separate construction may be an existing construction. Alternatively, the separate construction may be a construction under construction. The separate structure can be, for example, one of the following structures: tower of an existing wind farm or a wind farm under construction; a mast, such as a radio mast or a television mast or an electricity mast or a mobile mast; a pole, such as a lamppost or a telegraph pole; a chimney.

In the following, the present invention will be explained in more detail with reference to the figures with a number of non-limiting embodiments, — where:

Figure 1 shows a schematic illustration of a wind turbine according to the present invention comprising a first turbine rotor and a second turbine rotor which are counter-rotating rotors.

Figure 2 shows a schematic illustration of the second turbine rotor with the windings of the coil of the stator of the electric generator.

Figure 3 shows a schematic illustration of a wind turbine according to the present invention comprising a lower first turbine rotor and an upper first turbine rotor arranged on a common shaft and on each side of the second turbine rotor in the longitudinal direction of the wind turbine.

Figure 4 shows a schematic illustration of a wind turbine according to the present invention comprising a first turbine rotor and a second turbine rotor as shown in Figure 1, and an outer second turbine rotor securely attached to the second turbine rotor and disposed circumferentially on the outside of the first turbine rotor relative to the first turbine rotor.

Figure 5 shows a schematic illustration of a wind turbine according to the present invention comprising a number of support arms that support at least one turbine blade each, and where the support arms are provided with an outer support arm to which the turbine blades are rotatably attached.

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Figure 6 shows a schematic illustration of a wind turbine according to the present invention, where four counter-rotating turbine rotors are mounted on the tower of a wind power plant.

Figure 7 shows a schematic illustration of a wind turbine according to the present invention, where three turbine rotors, as shown in Figure 3, are mounted on the tower of a wind power plant.

As indicated in the figures, the axis of rotation A of all embodiments of the wind turbine 12 shown in figures 1-7 is arranged at a substantially right angle, or perpendicular, to the direction of the wind. Therefore, the axis of rotation A of the wind turbine 12 is essentially vertical—relative to a horizontal ground surface 56 or sea surface 56 (see Figures 6 and 7).

The wind turbine 12 is therefore a vertical axis wind turbine (VAWT). It should also be mentioned that the longitudinal direction of the wind turbine 12 extends in the same direction as the axis of rotation A. It should be mentioned, however, that the axis of rotation A and the longitudinal direction of the wind turbine and the tower can be arranged so that they are inclined in relation to a horizontal plane. This may be suitable for, for example, floating wind turbines placed in water.

In Figure 1, a wind power plant 10 according to the present invention is shown comprising a wind turbine 12. The wind turbine 12 is mounted on a tower 13, which can be a tower 13 of an existing structure, such as an existing wind power plant, but can also be a mast, post , the chimney or any other suitable existing structure on which the wind turbine 12 can be retrofitted.

The wind turbine 12 can also be mounted on a tower 13, or similar construction, when the tower is built.

The wind turbine shown in figure 1 comprises a first turbine rotor 16 which is rotatably mounted on the tower 13 around a rotation axis A, and a second turbine rotor 23 which is also rotatably mounted on the tower 13 around the same rotation axis A.

The first turbine rotor 16 is supported on at least one, but preferably two or more first turbine rotor bearings 31, which allow the first turbine rotor to rotate around the axis of rotation A and ensure that external forces on the first turbine rotor 16 are absorbed and transmitted to the tower 13.

Correspondingly, the second turbine rotor 23 is supported by at least one, but preferably two or more second turbine rotor bearings 32, which allow the second turbine rotor to rotate around the axis of rotation A and ensure that external forces on the second turbine rotor 23 are absorbed and transmitted to the tower 13.

The first turbine rotor 16 and the second turbine rotor 23 are arranged so that they rotate in opposite directions around the axis of rotation A when the wind turbine 12 is

1 DK 202200086 U3 in operation, i.e. the first turbine rotor 16 and the second turbine rotor 23 are counter-rotating turbines.

As indicated in the figures, the axis of rotation A of the wind turbine 12 is placed essentially at a right angle, or perpendicular, to the direction of the wind. Therefore, the axis of rotation A of the wind turbine 12 is essentially vertical relative to a horizontal ground surface 56 or sea surface 56 (see Figures 6 and 7). The wind turbine 12 is therefore a vertical axis wind turbine (VAWT). As mentioned above, the axis of rotation can

A and the longitudinal direction of the wind turbine and the tower also be placed so that they are inclined in relation to a horizontal plane. It may be suitable for, for example — wind turbines placed floating in water.

The wind turbine 12 is provided with a generator 35 for the production of electrical energy. The generator 35 comprises a first generator part 36, which comprises the magnets of the generator 35, and a second generator part 38, which comprises the windings of the generator 35. The first generator part 36 can be mounted on the — first turbine rotor 16, as shown in figure 1, so that the first generator part 36 faces the second turbine rotor 23. The second generator part 38 can be mounted on the second turbine rotor 23, as shown in Figure 1, so that the second generator part 38 faces the first turbine rotor 16.

In Figure 2, the second turbine rotor 23 is schematically shown with the second generator part, — including its windings, mounted on the second turbine rotor 23.

Alternatively, the second generator part 38, comprising the angled blades of the generator 35, is mounted on the first turbine rotor 16, and the first generator part 36, comprising the magnets of the generator 35, is mounted on the second turbine rotor 23. — The generator 35 is preferably mounted on a radially peripheral part of the turbine rotors 16, 23, i.e. at the outer part of the turbine rotors 16, 23 in relation to the axis of rotation

A. This will provide a greater relative speed between the magnets of the first generator part 36 and the winding of the second generator part 38. Therefore, as indicated in Figure 1, and also in Figures 3-4, the first generator part 36 is mounted on a radially peripheral first part 17 of the first turbine rotor 16 facing the second turbine rotor 23 and the second generator part 38 is mounted on a radially peripheral second part 24 of the second turbine rotor 23 facing the first turbine rotor 16.

As shown in Figure 1, the wind turbine 10 is further provided with a slip ring 41, which is mounted on the second turbine rotor 23. The wind turbine 10 is further provided with brushes 42, which are mounted on the tower 13 and cooperate with

1 DK 202200086 U3 the slip ring 41 so that electrical energy produced by the generator 35 can be exported from the wind turbine 12 and transferred to any desired external location.

Figure 3 shows an embodiment of a wind turbine 12 according to the present invention, which is slightly different from the wind turbine 12 shown in Figure 1.

Instead of a single first turbine rotor 16, the wind turbine 12 shown in Figure 3 comprises an upper first turbine rotor 19 and a lower first turbine rotor 20. The upper first turbine rotor 19 and the lower first turbine rotor 20 are both mounted on a first turbine shaft 21.

The upper first turbine rotor 19 and the second turbine rotor 20 are placed with — space in the longitudinal direction of the wind turbine 12, i.e. in the direction of the rotation axis A, and the second turbine rotor 23 is arranged between the upper first turbine rotor 19 and the lower first turbine rotor 20.

The second turbine rotor 23 is securely mounted on a second turbine shaft 25. The second turbine shaft 25 is rotatably mounted on the first turbine shaft 21 as indicated in Figure 3. The second turbine shaft 25 is supported by at least one, but preferably two or more second turbine rotor bearings 32, which allows the second turbine rotor to rotate around the rotation axis A, in the opposite direction to the upper first turbine rotor 19 and the lower first turbine rotor 20, and to ensure that external forces and loads on the second turbine rotor 23 are absorbed and transmitted to the first turbine shaft 21 and subsequently to the tower 13. The upper and lower first turbine rotors 19, 20 and the second turbine rotor 23 are therefore counter-rotating turbines.

The first turbine shaft 21 is rotatably mounted on the tower 13 about the axis of rotation A. The first turbine shaft 21 is supported on at least one, but preferably two or more first turbine rotor bearings 31, which allow the lower first turbine rotor 20 and the upper first turbine rotor to rotate about axis of rotation A and ensure that external forces and loads on the lower first turbine rotor 20, the upper first turbine rotor 19 and the second turbine rotor 23 are taken up and transferred to the tower 13.

As in the embodiments shown in Figure 1, the generator 35 comprises a first generator part 36, comprising the magnets of the generator 35, and a second generator part 38 comprising the windings of the generator 35. The first generator part 36 can be mounted on the upper first turbine rotor 19, preferably on a peripheral first part 17 of the upper first turbine rotor 19 as indicated in Figure 3, and the second — generator part 38 can be mounted on the second turbine rotor 23, preferably on a peripheral second part 24 of the second turbine rotor 23, or vice versa.

DK 202200086 U3

Of course, as an alternative, the first generator part 36 can be mounted on the second turbine rotor 23, preferably on a peripheral second part of the second turbine rotor 23, and the second generator part 38 can be mounted on the lower first turbine rotor 20, preferably on a peripheral first part of the lower first turbine rotor 20, or 5 > vice versa.

Although not shown in Figure 3, the wind turbine 10 is further provided with a slip ring which can be mounted on the upper first turbine rotor 19 or the first turbine shaft 21, and brushes which are mounted on the tower 13 above the wind turbine 12.

The brushes cooperate with the slip ring so that electrical energy produced by the generator 35 can be exported from the wind turbine 12 and transferred to any desired external location.

Figure 4 shows a further embodiment of a wind turbine 12 according to the present invention. The wind turbine 12 comprises a first turbine rotor 16 which is rotatably mounted on the tower 13 around the axis of rotation A, and a second turbine rotor 23 which is also rotatably mounted on the tower 13 around the same axis of rotation A.

The first turbine rotor 16 is supported on at least one, but preferably two or more first turbine rotor bearings 31, which allow the first turbine rotor to rotate around the axis of rotation A and ensure that external forces on the first turbine rotor 16 are absorbed and transmitted to the tower 13.

Correspondingly, the second turbine rotor 23 is supported by at least one, but preferably two or more, second turbine rotor bearings 32, which allow the second turbine rotor to rotate around the axis of rotation A and ensure that external forces on the second turbine rotor 23 are absorbed and transmitted to the tower 13.

The first turbine rotor 16 and the second turbine rotor 23 are arranged so that they rotate in opposite directions around the axis of rotation A when the wind turbine 12 is in operation, i.e. the first turbine rotor 16 and the second turbine rotor 23 are counter-rotating turbines.

The wind turbine 12 is further provided with an outer second turbine rotor 28. As — indicated in Figure 4, the outer second turbine rotor 28 is arranged radially on the outside of the first turbine rotor 16 in relation to the axis of rotation A and extends around the first turbine rotor 16 in the circumferential direction of the windmill 12.

The outer second turbine rotor 28 is supported by at least one, but preferably a plurality of support elements 28 as indicated in Figure 4. The support elements 28 are securely — attached to the second turbine rotor 23 and to the outer second turbine rotor 23, for example by welding or with bolts, screws or other suitable fastening means. The second turbine rotor 23 and the outer second turbine rotor 28

DK 202200086 U3 therefore rotates together as a unit when the wind turbine 12 is in operation. The first turbine rotor 16 and the second and outer second turbine rotors 23, 28 are therefore counter-rotating turbine rotors.

As for the other embodiments of the present invention, > the generator 35 comprises a first generator part 36 which comprises the magnets of the generator 35, and a second generator part 38 which comprises the windings of the generator 35. The first generator part 36 can be mounted on the first turbine rotor 16 as shown in figure 4, so that the first generator part 36 faces the second turbine rotor 23. The second generator part 38 can be mounted on the second turbine rotor 23 as shown in figure 4, so that the second generator part 38 faces the first turbine rotor 16.

Alternatively, the second generator part 38 , comprising the angled blades of the generator 35 , is mounted on the first turbine rotor 16 , and the first generator part 36 , comprising the magnets of the generator 35 , is mounted on the second turbine rotor 23 .

As with the other embodiments of the present invention, the generator 35 is preferably mounted on a radially peripheral portion of the turbine rotors 16, 23, ie. at the outer part of the turbine rotors 16, 23 in relation to the axis of rotation A.

This will provide a greater relative speed between the magnets of the first generator part 36 and the windings of the second generator part 38.

Therefore, as indicated in Figure 4, the first generator part 36 is mounted on a radially peripheral first part 17 of the first turbine rotor 16 which faces the second turbine rotor 23, and the second generator part 38 is mounted on a radially peripheral second part 24 of the second turbine rotor 23 which faces the first turbine rotor 16.

Although not shown in Figure 4, the wind turbine 10 is further provided with a slip ring which is preferably mounted on the second turbine rotor 23.

The wind turbine 10 is also provided with brushes which are mounted on the tower 13 and cooperate with the slip ring so that electrical energy produced by the generator 35 can be exported from the wind turbine 12 and transferred to any desired external location.

The wind turbine 12 can be provided with a well-known construction type comprising a number of support arms that extend outwards in a radial direction relative to the axis of rotation

A. The support arms are preferably evenly distributed around the wind turbine 12 in the wind turbine's peripheral direction 12 around the axis of rotation A.

The Hyver support arm can support a single turbine blade that is pivotally mounted on a radially outer portion of the support arm. Alternatively, each support arm can support one

DK 202200086 U3 plurality of turbine blades distributed along the support arm with a desired distance between them.

Each support arm preferably comprises an upper support arm and a lower support arm.

The turbine vane or turbine vanes are then arranged between the upper support arm and the lower support arm and are pivotally mounted to the upper support arm and the lower support arm in a manner well known in the art. When the wind turbine 12 is in operation, the turbine blades of the support arms are continuously rotated to a desired position relative to their respective support arms depending on the rotational position of the wind turbine to provide the greatest possible and/or desirable wind power on the wind turbine 12.

Instead of using the well-known design of turbine rotors described above, an alternative turbine rotor can be used as shown in Figure 5.

Figure 5 shows a possible version of the wind turbine 12 comprising eight support arms 45 which are securely attached to a central turbine rotor support element 14 in the wind turbine 12. The support arms 45 are evenly distributed in the circumferential direction around the tower 13.

As indicated in figure 5, the wind turbine 12 can be provided with 8 support arms 45, but the wind turbine 12 can of course be provided with any number of support arms 45 which would be suitable for any given hydroelectric plant 10.

The support arms 45 preferably extend outwards in an essentially radial direction from the tower 13. At the radially outer end part of the support arms 45, an outer support arm 50 is mounted as indicated in the figure. The outer support arms 50 are articulated, i.e. they are rotatably attached to respective support arms 45 by a connecting device 51 which enables the outer support arms 50 to rotate relative to the support arms 45.

The connecting devices 51 can be provided with activation means so that the rotation of the outer support arms 50 in relation to the support arms 45 can be controlled so that the outer support arms 50 are continuously rotated to a desired position in relation to their respective support arms 45 when the wind turbine 12 rotates. As indicated in Figure 5, the desired position of the outer support arms 50 in relation to their respective support arms 45 will change during a full rotation of the turbine rotor around the axis of rotation A and depends on where in the rotation cycle of the turbine rotor the support arms 45 are located at any time.

The actuation means may be a motor, such as an electric motor, or a hydraulic device, such as a piston/cylinder assembly, or a mechanical system comprising chains or drive belts, or any other suitable actuation means capable of rotating the outer support arms 50 relative to their respective support arms 45.

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As indicated in Figure 5, a turbine blade 47 is rotatably mounted on an outer end part of the outer support arms 50, preferably with respective turbine blade connecting devices 48. It should be mentioned that two or more turbine blades 47 can be mounted on each outer support arm 50 distributed along the outer support arm 50. One or more turbine blades can also be mounted on the support arm 45 distributed along the support arm 45.

The turbine blade connecting devices 48 are preferably also provided with activation means, so that the rotation of the turbine blades 47 in relation to the outer support arms 50 can be controlled so that the turbine blades 47 are continuously rotated to a — desired position in relation to their respective outer support arms 50 when the wind turbine 12 rotates, and the outer support arms 50 rotate relative to their respective support arms 45. The actuation means may be a motor, such as an electric motor, or a hydraulic device, such as a piston/cylinder unit, or a mechanical system comprising chains or drive belts, or any other suitable actuation means , capable of rotating the turbine blades 47 relative to their respective outer support arms 50.

The wind turbine 12 may also include spring elements to facilitate the movement of the outer support arms 50 relative to the support arms 45 and/or the movement of the turbine blades 47 relative to the outer support arms 50 and/or the support arms 45 — and/or to help recover at least some of the energy used to affect the rotational movement of the outer support arms 50 relative to their respective support arms 45 as the outer support arms 50 rotate between a first extreme position and a second extreme position relative to the support arm 45, i.e. an imaginary line through or imaginary extension of the support arm 45 when the wind turbine rotates around — about the axis of rotation A during operation of the wind turbine.

Although not shown in the figures, each outer support arm 50 preferably comprises an upper outer support arm and a lower outer support arm, and optionally, but preferably, each support arm 45 is provided with an upper support arm and a lower support arm, even if no turbine blades are mounted on the support arms 45. The turbine blade 47, or — the turbine blades, is then positioned between the upper outer support arm and the lower outer support arm and is pivotally mounted on the upper support arm and the lower support arm in a manner well known in the art.

The wind turbine shown in Figure 5 is provided with eight support arms 45 and eight respective outer support arms 50 which are rotatably mounted on respective support arms 45 with a — connecting device 51. A brief description of the rotation of the outer support arms relative to their respective support arms 45 when the wind turbine 12 rotates counter-clockwise due to the wind indicated by the arrow P.

DK 202200086 U3

When the wind turbine 12 is in operation, the turbine blades of the support arms are continuously rotated to a desired position relative to their respective support arms depending on the rotational position of the wind turbine to provide the greatest possible and/or desirable wind power on the wind turbine 12. The rotation of the outer support arms 50 relative to — the support arms 45 in different positions during the rotational movement of the wind turbine 12 are indicated by arrow V in each of the eight positions, i.e. for each of the eight outer support arms 50 when the wind turbine 12 is placed in this specific position in its continuous counter-clockwise rotational movement.

A turbine blade 47 of the turbine rotor shown in Figure 5 generates energy as it moves from the position shown by the letter A until it reaches the position shown by the letter E. In the position indicated by the letter

A, the outer support arm 50 is placed in its first outermost position where it is rotated clockwise relative to a straight line through support arm 45 indicated by broken line B.

As the turbine rotor rotates counterclockwise, the outer support arm 50, located in position A, starts its rotation, indicated by the arrow Ta, relative to the support arm 45 toward its second outermost position relative to the support arm 45. Between the positions indicated by the letters A and C, the lift force on the turbine blade 47 is greater than the opposing forces caused by the headwind, and the turbine blades 47 contribute to the power generation. By turning the outer support arms 47 in the direction indicated by arrow Tp from position A, the lifting force on the turbine blades 47 is increased.

At the position indicated by the letter C, the outer support arm 50 has been rotated relative to the support arm 45 so that they lie in a straight line, and continues to be rotated toward the second outermost position relative to the support arm 45 as indicated by arrow Vc In the position indicated by the letter E, the outer support arm 50 is located in its second outermost position in relation to the support arm 45.

The angle that the outer support arms 50 make with a straight line through their respective support arms 45 when the outer support arms 50 are positioned in the first extreme position or the second extreme position may vary from one turbine rotor to another and from one wind turbine 12 to another, but can be any — angle in the range of 0-45 degrees. The support arms 45 and/or the outer support arms 50 and/or the connection devices 51 can further be arranged with adjustable stop devices which make it possible to adjust the first outermost angle and/or the second outermost angle which the outer support arms 50 give in relation to the support arms 45 to a desired angle depending, for example, on prevailing wind and — weather conditions.

When the outer support arms 50 move between the positions indicated by the letters C and I, they have a tailwind, and between the positions indicated by the letters E and G, the turbine blades 47 actually move faster than the wind, so that the turbine blades 47 experience a headwind . To counteract this headwind, rotate

DK 202200086 U3 the outer turbine blades 47 again in the opposite direction, and the speed of the turbine blades 47 is less than the wind speed, and the turbine blades 47 contribute to the energy production in this phase. From the position indicated by the letter

E, the outer support arm 50 is turned in the direction indicated by the letter VE in 5 — relative to the support arm 45, i.e. in the opposite direction to the wind direction P until the outer support arms 50 reach their first outermost position again, i.e. the outer support arms 50 have the same position in relation to the support arms 45 in the positions indicated by the letters A and G.

Between the positions of the outer support arms indicated by the letters G and

K, the turbine blades 47 will again be exposed to a lifting force that contributes to electricity production. To increase the lift forces on the turbine blades 47, the outer support arms 50 are rotated relative to their respective support arms 45, from the first extreme position they have in position G, in the direction indicated by the arrow Tg to the second extreme position they have in the position indicated by the letter K. — When the turbine rotor rotates so that the outer support arms 50 move from the position indicated by the letter K to the position indicated by the letter A, the outer support arms 50 are rotated in the direction indicated by the arrow Vk and VL relative to the support arms 45, from the second outermost position of the outer support arms 50 in the position indicated by the letter K to the first outermost position of the outer support arms 50 in the position indicated by the letter A. As the can be seen in figure 5, the outer support arms will be closer to each other in this phase, and the outer support arm(s) in front will cover the rear support arm(s) to some extent, and the result is that in total less headwind is created on the outer support arms 50.

The wind turbines 12 shown in figures 1-5 can be mounted on various types of towers, masts, poles, chimneys or other types of suitable constructions. The wind turbines 12 can be retrofitted on separate, existing structures. Alternatively, one or more wind turbines according to the present invention are integrated into a supporting structure, such as a tower, when the supporting structure is built. Such a separate structure can be a tower of an existing wind power plant or a — wind power plant under construction. The separate structure may also be a mast, such as a radio mast or a television mast or an electricity mast or a mobile mast, or it may be a pole, such as a lamppost or a telegraph pole, or it may be a chimney, for example a chimney of a power plant.

In Figures 6 and 7, two examples of wind power plants 10 are shown comprising wind turbines 12 according to the present invention.

Figure 6 shows a wind power plant 10 comprising a separate construction 53 in the form of a wind power plant with a horizontal axis comprising a fastening structure 54 in the form of a tower. The fastening structure 54 can be erected on the ground surface 56 or placed

DK 202200086 U3 in a water area with a water surface 56. Two counter-rotating wind turbines 12 according to the present invention, each comprising a first turbine rotor 16 and a second turbine rotor 23 as described above, are shown mounted on the attachment structure 54, i.e. the tower 54. In Figure 6, two wind turbines are mounted on — the attachment structure 54, i.e. the tower of the wind farm in this case, but any desired number of wind turbines 12 can be mounted on a fastening structure. When a number of wind turbines 12 are stacked on top of each other, each can be adjusted for distance above ground or water surface 56, as they will be mounted to account for varying wind conditions, turbulence, etc., which depend on the location of the wind turbine, the surrounding terrain and the distance above the ground surface 56.

In Figure 7, a wind turbine 10 is shown comprising a similar separate structure 53 to that shown in Figure 6. The separate structure 53 is a horizontal axis wind turbine comprising an attachment structure 54 in the form of a tower 54.

The attachment structure 54 can be erected on the ground surface 56 or placed in a body of water with a water surface 56. A counter-rotating wind turbine 12 according to the present invention, comprising an upper first turbine rotor 19, a lower first turbine rotor 20 and a second turbine rotor 23 as described in connection with Figure 3 above is shown mounted on the attachment structure 54, i.e. the tower 54. In Figure 7, a wind turbine 12 is mounted on the fastening structure 54, i.e. the tower of — the wind farm in this case, but again, any desired number of wind turbines 12 can be mounted on the attachment structure 54. Again, when a number of wind turbines 12 are stacked on top of each other, each can be adjusted to the distance above the ground or water surface 56, as they will be mounted to account for varying wind conditions, turbulence, etc., which depend on the location of the wind turbine, the surrounding terrain, and the distance above the ground surface 56. In addition, the upper first turbine rotor 19 and the lower first turbine rotor 20 can be designed differently so that the can be adapted to different wind conditions and turbulence that the upper first turbine rotor 19 and the lower first turbine rotor 20 may experience as they are located at different heights above the ground surface or the water 56.

Claims (29)

DK 202200086 U3 USE MODEL REQUIREMENT 1. A wind turbine (12) comprising at least a first turbine rotor (16) and a second turbine rotor (23), where the first turbine rotor (16) and the second turbine rotor (23) rotate around the same axis of rotation (A), whose axis of rotation ( A) extends in the longitudinal direction of the wind turbine (12), and the first turbine rotor (16) and the second turbine rotor (23) are counter-rotating, the wind turbine (12) further comprises a generator (35) which comprises a first generator part (36) and a second generator part (38), in which the first generator part (36) is mounted on the first turbine rotor (16) so that it faces the second turbine rotor (23), and the second generator part (38) is mounted on the second turbine rotor ( 23) so that it faces the first turbine rotor (16) and wherein the first generator part (36) comprises at least one generator magnet and the second generator part (38) comprises at least one generator coil for generating an electric current when the wind turbine (12 ) is in operation, in which the first generator part (36) is mounted on a radially peripheral first part (17) of the first turbine rotor (16) which faces the second turbine rotor (23), and the second generator part (38) is mounted on a radially peripheral second part (24) of the second turbine rotor (23) faces the first turbine rotor (16). 2. The wind turbine according to claim 1, in which the first turbine rotor (16) comprises an upper first turbine rotor (19) and a lower first turbine rotor (20), which are arranged on opposite sides of the second turbine rotor (23) in the longitudinal direction of the wind turbine (12) ). 3. The wind turbine according to claim 2, in which the upper first turbine rotor (19) and the lower first turbine rotor (20) are mounted on a first turbine shaft (21) which is arranged to be rotatably mounted on a tower (13) of a wind power plant (10) or a fastener (54) of a separate construction (53). 4. The wind turbine according to claim 3, in which the second turbine rotor (23) is rotatably mounted on the first turbine shaft (21). 5. The wind turbine according to one of claims 2-4, in which the upper first turbine rotor (19) and the lower first turbine rotor (20) have different diameters and/or different lengths in the longitudinal direction of the wind turbine (12). 6. The wind turbine according to one of claims 2-5, in which the lower first turbine rotor (19) has a smaller diameter and/or a smaller length than the upper first turbine rotor (20). 0 DK 202200086 U3 7. The wind turbine according to one of claims 2-6, in which the first generator part (36) is mounted on a radially peripheral first part (17) of the upper first turbine rotor (19) or the lower first turbine rotor (20) which faces the other turbine rotor (23), and the second generator part (38) is mounted on a radially peripheral second part (24) of the second turbine rotor (23) facing the upper first turbine rotor (19) or the lower first turbine rotor (20). 8. The wind turbine according to one of claims 1-7, wherein the wind turbine (12) comprises an outer second turbine rotor (28) which is arranged radially outside the first turbine rotor (16) and is securely attached to the second turbine rotor (23). 9. The wind turbine according to claim 8, in which the first turbine rotor (16) and the outer second turbine rotor (28) have substantially the same length in the longitudinal direction of the wind turbine (12). 10. The wind turbine according to one of claims 1-9, in which each turbine rotor (16, 19, 20, 23, 28) comprises at least one support arm (45) which extends in an essentially radial direction relative to the axis of rotation (A) , and at least one turbine blade (47) which is mounted on the support arm (45). 11. The wind turbine according to claim 10, in which at least one turbine blade (47) is rotatably mounted on the at least one support arm (45). 12. The wind turbine according to claim 10 or 11, in which at least one turbine blade (47) extends in a direction that is essentially parallel to the axis of rotation (A). 13. The wind turbine according to any one of claims 10-12, in which the at least one support arm (45) comprises a first support arm and a second support arm which are distributed in the longitudinal direction of the wind turbine (12), and in which the at least one turbine blade (47) is rotatable mounted on the first support arm and on the second support arm. 14. The wind turbine according to one of claims 10-13, in which each turbine rotor (16, 19, 20, 23, 28) comprises a plurality of support arms (45), and in which at least one turbine blade (47) is mounted on each support arm (45) . 15. The wind turbine according to one of claims 10-14, in which each support arm (45) is provided with an outer support arm (50) which is rotatably connected to the support arm (45) at a radially outer part of the support arm (45). 1 DK 202200086 U3 16. The wind turbine according to claim 15, in which at least one turbine blade (47) is mounted on each outer support arm (50). 17. The wind turbine according to claim 15 or 16, in which at least one turbine blade (47) is rotatably mounted on the outer support arm (50) and/or at least one turbine blade (47) is rotatably mounted on the support arm (45). 18. The wind turbine according to one of claims 15-17, in which a plurality of turbine blades (47) are rotatably mounted on each support arm (45) and/or the outer support arm (50), distributed in a radial direction relative to the axis of rotation (A) along the length of the support arm (45) and/or the outer support arm (50). 19. The wind turbine according to one of the claims 15-18, in which the outer support arm (50) is arranged to be actively rotated relative to the support arm (45) as the turbine rotors (16, 19, 20, 23, 28) rotate around the axis of rotation (A). 20. The wind turbine according to claim 19, in which each support arm (45) is provided with a motor that rotates the outer support arm (50) in desired positions in relation to the support arm (45). 21. The wind turbine according to claim 20, in which the wind turbine (12) comprises a control system that controls the motors in the support arms (45) so that each outer arm (50) is rotated to a desired position in relation to the support arm (45), to which it is rotatably attached , depending on the rotational position of the support arm (45) when the turbine rotors (16, 19, 20, 23, 28) rotate about the axis of rotation (A). 22. A wind power plant (10) comprising a separate structure (53) and a wind turbine (12) according to any one of claims 1-21, wherein the wind turbine (12) is mounted on the separate structure (53). 23. The wind power plant according to claim 22, wherein the separate structure (53) is an existing structure. 24. The wind power plant according to claim 22, wherein the separate structure (53) is a structure under construction. 25. The wind power plant according to one of claims 22-24, in which the separate structure is a tower (13) of an existing wind power plant or a wind power plant under construction. > DK 202200086 U3 26. The wind power plant according to one of claims 22-25, in which the separate structure (53) is a mast, such as a radio mast or a television mast or an electric mast or a mobile mast. 27. The wind turbine according to one of claims 22-25, in which the separate structure (53) is a pole, such as a lamppost or a telegraph pole. 28. The wind power plant according to one of claims 22-25, in which the separate structure (53) is a chimney. 29. Use of a wind turbine according to any of claims 1-21 and/or a wind power plant according to any of claims 22-28 on an existing structure.