Patent Grant
11053103
The present invention relates to a lifting assembly for elevating components to the top of a wind turbine. The invention also relates to a method for using the lifting assembly for transportation of components to and from the top of a wind turbine during maintenance of the wind turbine.
Wind turbines today require regular maintenance of its main components, such as rotor blades, gear boxes and generators. However, these components are often large and heavy, which poses an issue during both the assembly and the maintenance of the wind turbines. For example, the gear boxes may weigh between 20-45 tons, and the generators may weigh between 15-30 tons. Today, the most common solution is to use large, heavy cranes that lift the components from the ground with long wires. One of the problems with these cranes is that they are highly sensitive to wind and cannot operate while the wind velocity exceeds certain limits, since the crane becomes too unstable and the wire might start to swing. This can result in stoppage of production for long periods of time, decreasing the profitability of the wind turbines. Additionally, the large size and weight of the cranes most commonly used today cause problems with transportation and assembly of the cranes. A large number of vehicles is required today to transport the different parts of the cranes, and once the transportation is completed, the assembly of these parts takes a very long time to finish. All the problems mentioned above cause the assembly and the maintenance of the wind turbines to become expensive and time-consuming.
U.S. Pat. No. 9,266,701 B2 discloses an enhanced stability crane, including a telescoping main support mast upon which a crane base resides. A boom projects upwardly from the crane base and a jib typically projects upwardly from the boom. The crane is adapted to have a load capacity of at least 160,000 pounds and a maximum jib height of at least 262 feet. This invention addresses the issue of stability by using a clamping assembly which resides on the main support mast and is configured to attach to an existing structure adjacent to the crane. This clamping assembly enhances the stability of the mast. The size and weight of the enhanced stability crane is also reduced in comparison to the cranes most commonly used today. However, a problem with this invention is that it does not account for the instability of the crane's wire, meaning it is still sensitive to high winds. Another disadvantage is that the crane residing on the main support mast is large and heavy, increasing the overall size and weight of the invention.
Accordingly, there is a need for a lifting assembly for lifting and positioning the main components of wind turbines, which are smaller in size, less heavy and more resistant to wind.
It is an aim of the present invention to at least partly overcome the above problems, and to provide an improved lifting assembly for wind turbines.
This aim is achieved by a lifting assembly as defined herein.
The lifting assembly comprises a plurality of tower segments which together form an elongated tower, a support frame for supporting the tower, a securing assembly securing the tower to the wind turbine, a crane, an upper platform vertically movable along the tower, and a lower platform vertically movable along the tower between the upper platform and the support frame, wherein the crane is disposed on the upper platform and the lower platform is provided with a storage area for supporting components, and the crane is adapted to move components to and from said storage area of the lower platform.
The upper platform is arranged movable along the tower between a lower and an upper position relative the support frame. The upper platform is used to transport the crane along the tower and to position the crane at a suitable vertical position relative the wind turbine. Having the crane mounted on the vertically movable upper platform allows the crane to be moved in a vertical direction along the wind turbine. The lower platform is arranged below the upper platform. Since the lower platform is vertically movable between the upper platform and the support frame and is provided with a storage area for supporting components, the lower platform can transport components between ground and the upper platform. The crane is capable to move the components between the storage area of the lower platform and the wind turbine. Due to the fact that the crane is transported by the upper platform and the components are transported by the lower platform, the weight of each of the platforms can be reduced. Further, the power needed to transport the components is reduced compared to if the crane and the component were transported on the same platform.
The components are placed on the storage area of the lower platform and moved between ground and the upper platform by means of the lower platform. The upper platform and accordingly the crane are located at a desired vertical location relative the wind turbine. The crane is adapted to move the components between the lower platform and the wind turbine when the lower platform is close to the upper platform. The crane can pick up the component from the storage area and move it to the wind turbine and vice versa. This is a far more stable way for transporting a component up to the top of a wind turbine than by e.g. using a large crane having long wires that can cause the component to start swinging. In the present invention, the lifting of the component onto the storage area is done in the lower position and the lifting of the component onto the wind turbine is done in the upper position. This allows for the lifting distance to be minuscule compared to the conventional methods where the component is lifted directly from the ground onto the top of the wind turbine.
The storage area is preferably designed for supporting components weighing more than 10 tons to allow the storage area to support heavy component of the wind turbine, such as the gear box, the generator and the turbine blades. This means that the storage area is designed to have the mechanical strength needed to support components weighing more than 10 tons. Preferably, the storage area is designed for supporting components weighing more than 20 tons, and most preferably more than 30 tons since the size and weight of the components varies depending on the size of the wind turbine.
According to an aspect, the area of the storage area is at least 4 m2. Thus, the storage area provides enough space for supporting the components.
Having the crane mounted on the upper platform allows the crane to be moved in a vertical direction along the wind turbine. The crane is adapted to move the components between the lower platform and the wind turbine when the lower platform is in close vicinity to the upper platform. Preferably, the crane is adapted to enable lifting of components weighing more than 10 tons. Preferably, the weight of the crane is more than 10 tons. A crane lighter than 10 tons might not be able to lift necessary objects, e.g. the components of the wind turbine and segments of the tower.
According to one aspect, each of the upper and lower platforms is provided with an opening adapted to receive the tower. The openings are aligned in a vertical direction so that the tower can extend through the openings and accordingly through the platforms. With the term “aligned in a vertical direction” is meant that they are arranged above each other with respect to the vertical line. Thus, the tower is allowed to penetrate through both openings at the same time. The openings in the platforms allow the platforms to have a stable and easy connection to the tower. Further, the opening allows the platform to protrude a distance at different horizontal directions from the tower. This provides for a plurality of spaces for housing heavy objects at opposite positions relative the tower such that the weights of the objects will balance each other during transportation of the platforms along the tower. This is particularly important when the platform is being moved upward or downward along the tower, since an unbalanced platform will cause wear of the drive mechanism moving the platform. This is also beneficial due to the fact that a balanced platform will not cause as much strain on the tower. Thus, the tower segments will wear less.
Since the openings are adapted to receive the tower, the openings and the tower segments preferably have a corresponding shape. According to an aspect, the openings and the peripheries of the tower are rectangular. A rectangular tower is easier and accordingly cheaper to manufacture.
According to one aspect, the upper platform comprises a second opening aligned in a vertical direction with the storage area to allow a component to be moved to and from the storage area through the second opening of the upper platform. The second opening makes it easier to move components between the upper and lower platforms. Further, the second opening facilities for the crane to move components between the storage area and the wind turbine.
According to an aspect, the lower platform comprises a base frame, and a support member having an upper surface defining said storage area, and the support member is arranged movable in a vertical direction relative the base frame. The movable support member makes it possible to move the storage area to the second opening of the upper platform, and by that facilitates transportation of components, such as a tower segments, between the upper and lower platforms.
According to an aspect, the lower platform comprises a lifting mechanism adapted to move the support member in a vertical direction relative the base frame. Thus, the storage area can be raised and lowered in relation to the second opening of the upper platform.
According to an aspect, the upper platform comprises a transportation unit adapted to move a tower segment between the second opening and the first opening. This makes it possible to automatically move tower segments between the first and second openings of the upper platform during building and dismantling of the tower. Thus, lifting assembly can be used for building and dismantling the tower, as well as for transportation of components to and from the wind turbine.
According to an aspect, the transportation unit comprises at least two transportation unit rails adapted to engage with a first engaging portion attachable to the tower segments, and a propulsion mechanism adapted to move tower segments from the second opening to the first opening by means of the transportation unit rails.
According to an aspect, the lower platform comprises a lower platform drive unit for the vertical movement of the lower platform and a lower platform power supply unit adapted to provide the lower platform drive unit with power, and the lower platform power supply unit and the storage area are arranged on opposite sides of the first opening of the lower platform. By arranging the power supply unit in this manner, its weight helps to compensate for the weight of the components being supported on the first storage area, meaning the platform will become more balanced in weight. This is particularly important when the platform is being moved along the tower since an unbalanced platform will cause wear on the drive unit.
According to an aspect, the tower segments comprise gear racks, the upper platform comprises an upper platform drive unit for the vertical movement of the upper platform, and at least one upper platform gear wheel driven by the upper platform drive unit and adapted to engage with the gear racks on the tower segments, and the lower platform comprises a lower platform drive unit for the vertical movement of the lower platform, and at least one lower gear wheel driven by the lower platform drive unit and adapted to engage with the gear racks on the tower segments.
According to an aspect, the securing assembly is attached to the upper platform. Thus, the upper platform and the tower are secured to the wind turbine.
According to an aspect, the securing assembly comprises two arms horizontally movable relative to each other and bent towards each other to allow them to clamp around the wind turbine. Thus, it is possible for the arms to clamp around the wind turbine and by that fixedly connect the tower and the upper platform to the wind turbine. The term “clamp around the wind turbine” is to be interpreted in a broad manner and covers that the arms are partly, as well as fully, surrounding the wind turbine.
According to an aspect, said arms are pivotally attached to the upper platform.
According to an aspect, the storage area is arranged on an upper part of the lower platform and a space for transportation of passenger is defined below the storage area.
Thus, the lower platform can be used for transportation of people, as well as components, at the same time.
According to an aspect, the support frame comprises a transfer unit adapted to move the tower in a horizontal direction relative the support frame. Thus, the horizontal distance between the tower and the wind turbine can be adjusted. Further, the horizontal distance between the upper and lower platforms, and the wind turbine can be adjusted.
According to an aspect, the support frame comprises at least two support frame rails adapted to engage with a second engaging portion attached to the tower, and the support frame comprises a propulsion mechanism adapted to linearly move the tower by means of the support frame rails.
The length of the tower depends on the height of the wind turbine. Preferably, the elongated tower is higher than 60 m, more preferably higher than 80 m, and most preferably higher than 100 m. However, if necessary the tower can be more than 120 m. The tower segments are adapted to be arranged on top of each other to form the tower. By means of arranging the tower segments on top of each other the tower's height can be modified, and the tower is also easy to dismantle, thus facilitating the transport of the tower. The number of tower segments can be varied in dependence on the height of the wind turbine and the length of the tower segments. Since a plurality of tower segments makes up the tower, each tower segment can be made at such a low height that the vehicles delivering the tower segment can do so without requiring any extra transporting measure as e.g. using an escort. The length of the tower segments may vary. In order to facilitate transportation of the tower segments, the length of the tower segments may vary between 2-10 m. However, it also possible to have tower segments with a length up to 24 m.
The invention will now be explained more closely by the description of different embodiments of the invention and with reference to the appended figures.
The storage area 16 is preferably designed for supporting components weighing more than 10 tons to allow the storage area to support heavy component of the wind turbine, such as the gear box, the generator and the turbine blades. This means that the storage area is designed to have the mechanical strength needed to support components weighing more than 10 tons. More preferably, the storage area is designed for supporting components weighing more than 20 tons, and most preferably more than 30 tons since the size and weight of the components varies depending on the size of the wind turbine. According to an aspect, the area of the storage area is at least 4 m2. Thus, the storage area provides enough space for supporting the components.
The upper and lower platforms 7, 8 are provided with openings 17, 18, respectively, adapted to receive the tower 9, as for example shown in
In this example, the upper platform 7 comprises one securing assembly 32. The securing assembly 32 comprises two arcuate arms 33 movable relative to each other in a plane perpendicular to the longitudinal axis of the tower. Accordingly, the two arcuate arms 33 are movable relative to each other in a horizontal plane. In one aspect, the arms 33 are pivotally attached to the upper platform 7 to allow the arms to be moved towards and away from each other. The arms are arranged rotatable about an axis in parallel with the longitudinal axis of the tower. The arcuate arms 33 are bent towards each other to allow them to clamp around the wind turbine and by that attach the upper platform 7 to the wind turbine. In one aspect, the arcuate arms are telescopic arms comprising a cover portion 34 and an extending portion 35. The extending portion 35 is adapted to at least partly be withdrawn into the cover portion 34 reducing the length of the arcuate arms 33. Suitably the extending portion comprises joints 37 allowing parts of it to curve and bend horizontally. In one example, the joints 37 are rotated by means of a wire extending through the arcuate arms 33 and connected to an outer end of the arcuate arms 33 and the upper platform 7. When the wire is then tensioned, the parts of the arcuate arms 33 comprising the joints 37 are curved inwards creating a better grip on the wind turbine 5.
In one aspect, the extending portion comprises three joints. The securing assembly 32 further comprises a rotating mechanism adapted to rotate the arcuate arms in the horizontal plane. In this example, the rotating mechanism is two hydraulic pistons 38 connected to each arcuate arm 33 and the upper platform 7. The hydraulic pistons are adapted to extend and retract, which causes the arcuate arms 33 to rotate in the horizontal plane. In this example, the securing assembly comprises a stability part 41 arranged on the upper platform 7. The stability part 41 is adapted to move linearly and by that increasing the stability of the tower by bearing against the wind turbine 5. The stability part 41 is adapted to bear against a portion of the wind turbine facing the first platform 7. The stability part prevents the tower 9 from tilting towards the wind turbine 5. By using the stability part along with the arcuate arms 33 on the wind turbine 5, the tower is locked from tilting in any direction relative the wind turbine 5.
In this example, the upper platform 7 comprises an upper platform drive unit 25. The upper platform drive unit 25 is adapted to move the upper platform 7 vertically. The upper platform 7 further comprises upper platform gear wheels 26 that are driven and turned by the upper platform drive unit 25. Suitably the upper platform gear wheels 26 are attached to opposite side of the first opening 17. The upper platform gear wheels 26 are adapted to engage with the gear racks 28 of the tower segment 13 as seen in
In this example, the lower platform 8 comprises a lower platform drive unit 29. The lower platform drive unit 29 is adapted to move the lower platform 8 in a direction parallel to the longitudinal axis of the tower, i.e. in a vertical direction. The lower platform further comprises lower platform gear wheels 30 that are driven and turned by the lower platform drive unit. Suitably the lower platform gear wheels 30 are attached to opposite side of the opening 18. The lower platform gear wheels 30 are adapted to engage with the gear racks 28 of the tower segment 13 as seen in
In this example, the lower platform 8 comprises a base frame 53 and a support member 65 having an upper surface defining the storage area 16. For example, the support member 65 is a square plate. However, other shapes are also possible. The support member is for example made out of steel or some kind of metal, but could also be made of any kind of high strength material such as carbon fibre. In one aspect, the support member 65 is arranged movable relative the base frame 53 in a vertical direction to allow the support area to be raised and lowered.
In this example, the base frame 53 comprises three sections. A first section 54 comprising in this example the power supply unit 39. A second section 56 arranged next to the first section comprising the opening 18, the lower platform drive unit 29 and the lower platform gear wheels 30. A third section 57 is arranged next to the second section 56. In one aspect the storage area 16 is arranged on the third section 57 as seen in
In this example, the storage area is arranged on the third section 57 as seen in
The support frame 11 comprises a plurality of support legs 46. The support frame 11 further comprises a transfer unit 58 adapted to move the tower in a horizontal direction relative to the support frame 11. In one example the transfer unit comprises two support frame rails 59 and support frame sliding portions (not shown) adapted to slide horizontally on the support frame rails 59. The sliding portions are locked from moving out of the support frame rails 59. Each sliding portion comprises one attachment mechanism for attaching the sliding portion to the tower 9 resulting in that the tower 9 becomes locked to the support frame 11. The tower 9 is adapted to move on the support frame rails 59 so to increase and decrease the distance between the tower 9 and the wind turbine 5. In one example the transfer unit 58 comprises a driving unit (not shown) adapted to move the tower 9 on the support frame rails 59. The driving unit can be powered by a e.g. generator or an extern source.
The method of moving a new component to the nacelle in the wind turbine 5 can be done in the same way as removing an old component but in reversed order.
The present invention is not limited to the embodiments disclosed but may be varied and modified within the scope of the following claims.
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| 18198258 | Oct 2018 | EP | regional |
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| Number | Date | Country | |
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| 20200102193 A1 | Apr 2020 | US |
