FI20245008A1 - Arrangement for converting the energy of water waves into a rotational motion - Google Patents

Abstract

Arrangement for converting the energy of water waves into a rotational movement, which comprises a body (2) arranged to rock according to a movement formed by the water waves, at least one elongated rotator shaft (3), which is supported on the body (2) rotating around its longitudinal axis (L). Two rotator elements (4, 5) are arranged on the rotator shaft (3), which are located in the longitudinal direction of the rotator shaft (3) at a distance relative to each other and whose centers of gravity are located on opposite sides of the longitudinal axis (L) relative to the direction of rotation of the rotator shaft (3). The rotator shaft (3) is directed in the direction of its longitudinal axis (L) parallel to a vertical plane which in section runs through the direction of advance of the movement of the water waves (W). The rotator shaft (3) rocks back and forth with the body (2) on said vertical plane which in section runs through the direction of advance of the movement of the water waves (W). The rocking of the rotator shaft (3) forces the centers of gravity of the rotator elements (4, 5) to rotate around the rotator shaft (3).

Description

Arrangement for converting the energy of water waves into rotational motion

The invention relates to an arrangement for converting the energy of water waves into rotational motion, comprising a frame arranged to rock in accordance with the motion forming the water waves, an elongated rotator shaft supported on the frame to rotate about its longitudinal axis.

A particular problem with known wave power plants is the irregular movement of the waves, the variation in wave size and wave period. It has been difficult to convert this back and forth movement into a rotational movement or other movement with good efficiency. Such a wave power plant is known, for example, from publication US 4,266,143.

Often, the functional parts of such systems are also in direct contact with the wave itself, usually below the surface, which creates significant disadvantages, such as corrosion. This leads to rapid wear of the parts and further frequent maintenance measures.

To some extent, these problems have been attempted to be reduced by, for example, a solution related to a wave power plant according to reference publication FI 122615 B, in which the gyration axis connected to the frame is arranged to rotate by means arranged in the power frame that cause the frame to gyrate.

However, achieving gyration requires a moderately complex structure, and the rotational motion achieved in this way does not result in a force-generating

N 25 ton and not very efficient in terms of uniformity. 5 3 The problem with both of these prior art is that the arrangement's moving z single mass (for example, the rotator 6 shown in FI 122615 B) results in

Q is a bit unbalanced. This leads to problems especially in low wave areas,

D 30 — because individual weights (masses) that may tilt the frame need

O a relatively large force initiating rotation that shallow waves do not create.

The purpose of the invention is to provide a new type of arrangement in which the above-mentioned problems have been eliminated or substantially reduced so that the reciprocating motion of the waves can be converted directly into continuous rotational motion.

This purpose is achieved by the invention on the basis of the features set out in the accompanying patent claim 1. —Preferred embodiments of the invention have been set out in the dependent patent claims. They have set out embodiments in which the arrangement according to the frame and the rotator shaft is applied to be placed directly in the wave and as part of a wave power plant. —The basic idea of the invention is to put a frame equipped with a rotator shaft, which is new compared to the prior art, into a rocking motion in accordance with the water waves, which in turn puts the rotator shaft into a rotating motion. This solution avoids the disadvantages of the prior art, where the parts that produce the motion are in contact with or at least exposed to the wave, most often — seawater. The arrangement according to the invention can also be applied in such a way that the frame with its rotor shaft can be placed, for example, in the interior of a watercraft (boat or ship), for example on the floor, where the frame moves in accordance with the movement of the water waves. In addition, the complex structures of the prior art are avoided, because the rotor shaft according to the invention requires only a

N 25 — only the front of the plane in the direction of the movement of water waves

O backward movement, and for example, no separate means 3 intended for gyration movement are needed. The arrangement according to the invention achieves an arrangement operating with good efficiency, in which the rotational movement of the rotator shaft is realized

Q efficiently and evenly even with slight water movement or small wave

D 30 — at a height. The arrangement according to the invention also achieves continuous

O balanced frame because the rotator elements are arranged in such a way that

that no imbalance can occur according to the state of the art. In this case, the rotational movement of the rotator shaft is also realized in shallow waves.

The rotator system according to the invention can also be used in a gyrating device. In this case, the rotator axis is positioned substantially parallel to the gyration axis.

In the following, the invention is illustrated by means of exemplary embodiments with reference to the accompanying drawing, in which

Figure 1 - schematically shows an arrangement of a half frame part according to one preferred embodiment of the invention.

Figure 1 thus shows an arrangement according to a preferred embodiment of the invention, in which the energy of water waves is converted into rotational motion. This arrangement includes a frame 2 intended to float with the water waves, of which Figure 1 shows approximately half of the frame 2 in the longitudinal direction. The frame 2 thus forms a float or pontoon, in which the other elements related to the arrangement can be placed in the manner described below. The frame 2 can — instead of being placed in the water, be placed inside a vessel (boat, ship) in the water, however, in such a way that the operating conditions described below are met.

A rotator shaft 3 is supported on the frame 2. In the embodiment according to Figure 1, there is one rotator shaft 3 and it is arranged on a support.

N 25 meen 6, which is arranged to be immobile relative to the outer shell of the frame 2 and

O is therefore part of the frame. Here, the rotator shaft 3 and the bracket 6 are located in the longitudinal direction of the frame 3 in the middle of the frame 3. The bracket 6 can as such form a frame that can be placed in the water wave-forming motion.

Q can be rocked, for example, on a platform arranged on a ship. 2 30

The arrangement according to the invention may comprise several rotator shafts 3 and supports 6 placed at a distance from each other along the length of the frame 2.

For example, for a frame 2 with a length of 50 meters, there may be 2-10 rotator shafts 3 per frame.

The support 6 is provided with bearings 6a, 6b, 6c and 6d or similar support elements, of which there are four in this case. The number of these can vary as required. The rotator shaft 3 is arranged to rotate around its longitudinal axis L on these bearings 6a, 6b, 6c and 6d. This rotation is depicted by a double arrow R. The rotator shaft 3 can therefore rotate in either direction. The support 6 is arranged in a space defined by the outer shell of the hull 2, whereby the rotator shaft 3, the support 6 and all other functional parts associated with it are separated from the water forming waves and the adverse effects caused by it, such as corrosion.

Two rotator elements 4 and 5 are arranged on the rotator shaft 3 according to the invention, which are located in the longitudinal direction of the rotator shaft 3 (in the direction of the longitudinal axis L) at a distance from each other. They are placed on the outer circumference of the rotator shaft 3 in such a way that their centers of gravity are located in the direction of rotation of the rotator shaft 3, i.e. on opposite sides of the longitudinal axis L in the circumferential direction of the rotator shaft 3. The shape of the rotator elements 4 and 5 can be selected appropriately, for example, taking into account the surrounding space and their desired mass. Figure 1 shows the rotator elements 4 and 5, which form a fan-shaped widening part on the circumference of the rotator shaft 3. Consequently, their centers of gravity are located in the radial s direction of the rotator shaft 3 outside the rotator shaft and on opposite sides of each other.

N 25 — on the sides of the longitudinal axis L. There may be several rotator elements in the rotor.

Per axis O, however, an even number so that the position of the final centers of gravity remains as mentioned above.

I

=

Q In the arrangement according to the invention, the rotator axis 3 is oriented longitudinally.

O 30 — with its back in the L direction, on average, in the direction of propagation of water waves W

S in the direction of the vertical plane passing through. In the embodiment according to Figure 1, it is preferable that the body 2 is an elongated floating body in a direction transverse to the direction of propagation W of the water wave movement. The cross-section of the wall of the body 2 is preferably oval or substantially oval in shape. The long axis of the oval is preferably at the height of the plane passing through the water surface or substantially at that height. The body 2 is therefore ideally oriented perpendicularly transversely to the direction of propagation W, but can therefore turn somewhat back and forth from this. For example, the angle of rotation can deviate and change perpendicularly transversely to the direction of propagation W by 1-40 degrees in either direction. The frame 2 may also be permanently mounted at a slight angle, for example at an angle of 1-40 degrees, whereby — the horizontal varying suction of the different phases of the wave causes the frame to rotate back and forth about a vertical axis. This varying rotation acts on the rotator (the axis must be horizontal in this application) in the same way as the rocking of the frame, contributing to the rotation and providing energy to the system.

In Figure 1, the rotator shaft 3 is arranged in the frame 2 such that the nominal direction of its longitudinal axis L is horizontal. In this case, the rotator shaft 3 swings back and forth on both sides of the horizontal plane with the frame 2 on average in a vertical plane passing through the direction of propagation W of the water wave movement. The extent of this back and forth movement depends on the height and amplitude of the water waves. This causes the rotator elements 4 and 5 to be subjected to a + "pulsating" accelerated rotational movement R with the waves along the longitudinal axis of the rotator shaft 3.

S L circumference applying a torque to the rotator shaft that turns it. 5 25 This arrangement enables the rotator shaft 3 to be placed in the frame 2 with a gear

S optionally so that it swings with the nominal direction vertical or

E in the direction that is between the horizontal and vertical directions back and forth with the body 2 on average along the direction of propagation of the water waves W

D on a vertical plane.

S 30

It is preferable that the frame 2 is anchored in place by anchoring or fastening means 2a intended for this purpose. The anchoring means 2a are preferably anchoring chains or ropes or the like, which are attached at their upper end to the part of the frame 2 that lags behind the direction of propagation W of the water wave movement and at their lower end to the seabed or to another fixed base arranged there (not shown). The anchoring means 2a arranged in this way enable the back-and-forth rocking movement of the frame 2 (marked by a double arrow R2) in a controlled manner and thus controlled or at least significantly more controlled rotation or phase angle of the rotator elements 4 and 5, the position of the centers of gravity and — acceleration (and rotation speed) in relation to the properties of the waves, such as amplitude and height. Such an anchoring arrangement contributes to increasing the energy production of the system. The anchoring means 2a can advantageously be adjusted according to the prevailing conditions so that the rotator shaft 3 according to the arrangement rotates optimally.

In addition, other arrangements can be implemented in such a hollow body 2, with which the arrangement according to the invention can be adapted to changing environmental factors, mainly the aforementioned wave properties. One such arrangement is additional tanks 2b, 2b' arranged inside, outside — and/or as part of the outer shell of the body 2, which can be filled with water. In addition to or instead of this, the additional tanks 2b, 2b' can be permanently filled with water, whereby water can be transferred between the additional tanks. In addition to the fact that their function is to change the weight of the body 2 and this arrangement in general,

The additional tanks 2b are placed at such points on the hull 2 that they can influence the distribution of the added weight in the hull 2. By adjusting the weight distribution 5 in this way, it is also possible to influence the tilt angle z of the hull 2, i.e. the angle at which the hull 2, and therefore also the rotator shaft 3, is tilted with respect to a horizontal plane, for example the level of the calm water surface, 3. In other words, this influences the angle (average

N 30 rin) rotator axis 3 is oriented along the direction of propagation W of the water wave motion.

N on a nice vertical plane.

This angle of inclination and the changed inertia caused by the transfer of the internal mass affect the hydrodynamic properties and the natural frequency of the hull. By adjusting the angle of inclination in this way, the hull 2 can be made to resonate with waves of different lengths (changing average amplitude of the waves) as needed. By changing the angle of inclination of the hull 2, the length of the hull in the direction of wave propagation W is affected, which in turn affects the natural frequency of the hull and the aforementioned resonance. In other words, by adjusting the angle of inclination of the hull 2, the arrangement according to the invention can be adapted to the changing wave pattern so that it resonates with the wave — and thus is able to maximize energy production.

Figure 1 shows only a schematic example of the additional containers 2b and 2b' located on one side of the support 6. The arrangement of the additional containers 2b and 2b' can be implemented in many ways, depending on the final size and location of the frame 2. In Figure 1, an additional container 2b is arranged in the area of the bottom of the frame 2 and an additional container 2b' is arranged on the side of the frame, on the same side as the attachment point of the anchoring means 2a. It is important, however, that the additional container can be filled and emptied completely or partially according to the circumstances.

It is also possible to use weights instead of or in addition to additional containers, the position of which can be changed relative to the frame 2 to achieve a different weight distribution in the frame. However, in this case, the total mass of the arrangement cannot be influenced.

S

& 25 — Thus, the arrangement implements a smooth and relatively small rotator axis

The rotation of the rotator axis 3 was in motion. In other words, the rotation of the rotator axis 3

The movement S is realized in a very small movement of water waves. For such an arrangement z it is very advantageous to equip the rotator shaft 3 with power take-off means 7 and

D forms a wave power plant from the above arrangement. This has been implemented

D 30 here with a generator 7 arranged on the rotator shaft 3 to provide power output

O ten. Here, the generator 7 is arranged in the longitudinal direction L of the rotator shaft 3 between the rotator elements 4 and 5. The operation of the generator, which is known per se, is not presented in more detail here. It should be noted, however, that here the rotor of the generator is arranged to rotate with the rotor shaft 3 and the stator surrounds the rotor of the generator. The stator is provided with means known per se for transferring the current generated by the generator 7 to a desired destination and/or for changing the properties to the desired ones.

The generator torque is controlled by a special control program, where the position of the rotator elements (masses) is constantly adjusted to the optimum position in relation to the varying acceleration using a variable speed target. When the acceleration is at its maximum, the rotator elements (masses) should be optimally positioned at a 90 degree angle to the direction of acceleration at the location of the rotator elements (masses). +

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Claims (9)

Patent claims 1. An arrangement for converting the energy of water waves into rotational motion, comprising a frame (2) arranged to rock in accordance with the movement forming the water waves, at least one elongated rotator shaft (3) which is supported on the frame (2) to rotate about its longitudinal axis (L), characterised in that two rotator elements (4, 5) are arranged on the rotator shaft (3), which are located in the longitudinal direction of the rotator shaft (3) at a distance from each other and whose centres of gravity are located on opposite sides of the longitudinal axis (L) with respect to the direction of rotation of the rotator shaft (3), that the rotator shaft (3) is oriented in the direction of its longitudinal axis (L) in the direction of a vertical plane passing through the average direction of propagation of the water waves, the rotator shaft (3) then rocking back and forth with the frame (2) in said vertical plane passing through the average direction of propagation of the water waves, which is the axis of the rotator shaft (3) rocking forces the center of gravity of each rotator element (4, 5) to rotate about the rotator axis (3). 2. An arrangement according to claim 1, characterized in that the frame (2) is a container or float formed to float on water waves, and the rotator shaft (3) is arranged in the space (S) defined by the walls of the container or float. 3. An arrangement according to claim 1 or 2, characterized in that the rotator shaft (3) is arranged in a support (6) arranged in connection with the frame (2). O 4. An arrangement according to any one of the above claims 1-3, characterized in that the rotator shaft (3) is equipped with power take-offs (7). 3 2 30 — 5. An arrangement according to claim 4, characterized in that the means for extracting the force O include a generator arranged on the rotator shaft (3). 6. An arrangement according to any of the above claims 1-5, characterized in that additional containers (2b, 2b") are arranged on the inside, outside and/or part of the outer shell of the frame (2), which can be filled with water and/or in which water can be transferred between the additional containers. 7. An arrangement according to claim 6, characterized in that the additional containers (2b, 2b") are positioned in such a way that they can influence the weight distribution in the frame 2 so that the tilt angle of the frame (2) changes. 8. An arrangement according to any one of the above claims 1-7, characterized in that the frame (2) is anchored in place by anchoring or fastening means (2a) intended for that purpose. 9. An arrangement according to claim 8, characterized in that the anchoring or fastening means (2a) are fastened at their upper end to the part of the hull 2 that is behind the direction of propagation (W) of the movement of the water waves. + N O N O 00 O I = 00 O O LO s N O N