SE532074C2 - Wave power - Google Patents

Description

2 Mechanical transmissions generally have a higher efficiency than hydraulic ones. For a mechanical transmission to be efficient, the vertical movement of the waves must be converted into a rotational movement in a single direction and the speed of an electric generator connected to the transmission must be stabilized. However, this can be difficult to achieve and leads to complicated constructions.

In a device as above with a drive rod, wire or chain, which is attached to the seabed or in a frame structure and which runs along or over a drive wheel stored in a fl island, this problem can be solved in the following way. When the drive is lifted by a scale, a driving force is created over the drive wheel. When the scale then falls, a backstop is released and the drive wheel is retracted using a counterweight. The driving then takes place only during the ascent of the road and stops completely when the wave sinks, which is not satisfactory. Attempts have been made to reverse the direction of rotation, so that an electric generator driven by the drive wheel is driven by the counterweight in the same direction even when the wave sinks. This can be said to be an energy accumulation and can increase the utilization rate by 100%. However, reversing the direction of a mechanical transmission twice per wave period is not entirely trivial. Although the direction of rotation can be rectified, the rotational speed also follows the speed of the vertical movement, which is also not satisfactory. This provides a low degree of utilization and high damping effects, since the mass of the generator must constantly be alternately accelerated and decelerated. To equalize the driving force and speed of a generator using a mechanical transmission, several floats can cooperate with a phase shift between them. However, this is very inefficient and requires that the ten fines are evenly distributed over a wave period, which in practice cannot be achieved.

A wave power plant of the type described above is disclosed in published French patent application 2869368, which comprises a floating plate or island. Ropes on the fl bait run ropes, one end of which is attached to the bottom and the other end carries a counterweight. The rotation of the trissomas is transmitted to generators. The speed of and power from the generator varies with the movements of the waves. A similar wave power plant is shown in U.S. Pat. A gear is available to shift up the speed of the wheel or pulley in the for öt to be suitable for driving a generator. U.S. Patent 5,889,336 and Japanese Patent Application Laid-Open No. 11-6472 disclose a similar wave power plant having a chain attached at one end to a bottom foundation and having a counterweight at its other end. The chain passes over a sprocket in a te desert. The sprocket is connected to a generator via a direct-acting transmission, which ensures that the generator always rotates in the same direction. The speed depends on the vertical speed of the island.

A wave power plant of a slightly different type is disclosed in U.S. Patent 4,241,579. A drive shaft is raised and lowered between the water surface and the bottom. A number of fl islands are connected via ropes to counterweights and the ropes pass around the common drive shaft for driving this only when each fl island has an upward movement. In the published British patent application- to eel? 3cn 2062113 shows a wave power plant with two different types of drive mechanisms, each of which comprises a flow and a counterweight / bottom foundation / additional tip and which acts on a common drive shaft via one-way couplings. Published patent application 2339071 uses a float which is fixed at one end of a chain and via the chain drifts around a drive shaft located above the water surface. The other end of the chain carries a counterweight, which is also located above the water surface.

The coupling to the drive shaft is of the one-way type and the drive shaft can be driven by a plurality of brackets with chains.

Published international patent application WO 2005/054668 discloses a wave power plant with a float which is connected to one end of a line. The other end of the line is rolled up more or less on a trurnma located at the seabed. The drum is connected to a return spring and a generator and drives the generator both when the seat is raised and lowered. In the wave power plant according to the published international patent application WO 03/058054, the solder acts as a winding drum for a line, the lower end of which is connected to a bottom fund. Inside the float is a return spring, upshift mechanism and generator. The generator is driven both by raising and lowering the fl öt.

DESCRIPTION OF THE INVENTION It is an object of the invention to provide an effective wave power plant.

In a wave power plant, the energy of water waves accumulates in some suitable way. For example, an accumulation solder can be used which is fixed to some elongate member, such as a line, which can be rolled up on an accumulation drum. The accumulation drum can be stored at an fl öte or at a frame placed on or attached to the bottom. The weight of the solder is connected to a generator and the position energy of the solder is utilized during the descending movement of the island. The generator is driven by the rising movement of the via öt via a drive shaft connected to another elongate member, also here for example a rope. As a result, a substantially constant torque over the rotor and stator of the generator can be achieved and thus a substantially constant relative rotational speed for the rotor and stator.

As an energy accumulating device, an elastic or resilient device can alternatively be used in which energy can thus be stored as a voltage in a spring or generally as elastic energy. Such an elastic device may comprise a gas pressure in a container connected to a combined grain press / pneumatic motor.

The energy accumulating device is coupled to the drive shaft to accumulate energy at either of the upward and downward movements of the water surface for driving the drive shaft at the other of the upward and downward movements of the water surface. This can be achieved in that the drive shaft is arranged to be able to rotate only in a single direction and is coupled to drive a first rotatable part in the generator and in that the energy accumulating device is connected to a second rotatable part in the generator. The magnetic coupling between the generator parts over the air gap in the generator then provides a limited torque counteracting the rotation of the drive shaft and the lithium filter 4 can drive the parts of the generator to rotate in the same direction relative to each other both when the first part is driven by the drive shaft and otherwise when the energy accumulating device instead drives the other part.

In such a wave power plant, with the aid of an energy storage device and suitable connections, the kinetic energy of the water waves can be equalized in an efficient manner.

The wave power plant may have one or more of the following features and advantages: l. Accumulation of energy as above can equalize the energy of the water waves and thereby provide a high degree of utilization for the generator while at the same time generating electrical power. 2. Ability to limit energy uptake from water waves, so that full power can be maintained instead of the plant having to be shut down at high wave heights. Possibility to dimension the wave power plant for a maximum capacity at an optimal average wave height. An electronically controlled slip clutch can be used, which is arranged to influence the winding of a line between a bottom foundation and the solder and which also makes it possible to regulate the force needed to maintain the horizontal position of the wave power plant. Such a slip clutch can replace and improve the function of a counterweight, herein referred to as an accumulation solder, which is often used in similar constructions.

. A drive drum mechanically coupled to the drive shaft can be used to more or less wind up the second elongate member in the form of a rope, according to the movements of the waves. The drive pulley can wind up several turns of the line. Mechanical connections can be provided, so that if the generator is supplied with electrical energy from the outside and functions as an electric motor, the drive can be forcibly controlled for controlled winding of the line. This can give the plant the property that it can be pre-assembled ashore and then towed to its installation site. 6. Installation can be done with minimal manual effort. In principle, only an electrical cable must be connected manually, which can be done at the water surface from a boat. A bottom foundation is attached to the second elongate member and the accumulation solder is hooked to the float during transport to the installation site and they can then be loosened by controlling mechanical couplings / locking device-BI. 7. The wave power plant can easily be designed so that it is suitable for different installation depths.

DESCRIPTION OF THE DRAWINGS The invention will now be described as a non-limiting exemplary embodiment with reference to the accompanying drawings, in which: - Fig. 1 is a schematic view of a wave power plant comprising four separate wave power plants, - Fig. 2a is a side view of a wave power plant with accumulation solder, - Pig. 2b is a front view of the wave power plant according to fi g. 2a, - Pig. 3a is a front view of a unit comprising winding drums, drive shaft and generator in the wave power plant according to fig. 2a, - Pig. 3b is a view similar to frg. 3a in which the part of a generator is schematically shown and in which a spiral spring is used as an energy storage device, - Fig. 3c is a front view of the winding window with specially designed winding surfaces, - Pig. 4 is a front view of the wave power plant according to fi g. Fig. 2a with specially designed electrical connection, - Fig. 5 is a detail view of a drive drum and its couplings located next to the shaft, - Fig. 6 is a detail view of a mechanical coupling between a drive drum and an accumulation drum, - Pig. 7 is a front view of an alternatively designed wave plant with accumulation solder, - Pig. 8 is a front view of another alternatively designed wave power plant with accumulation weight, - Pig. 9 is a front view of a wave power plant with accumulation device in the form of an elastic member, - Fig. 10 is a schematic front view of a wave power plant with energy accumulation and return drive.

DETAILED DESCRIPTION Fig. 1 shows a wave power plant for extracting energy from the motion of the waves at a water surface, for example from the movements of the seawater. It comprises one or more wave crayons 1, each of which comprises an island 3, which floats at the water surface and follows the movement of the waves. Thereby a driving force can be created in relation to the bottom, such as to a part fixedly attached to the bottom, for example a bottom foundation 5, which can have such a large mass that it is fixed to the bottom. If required, the bottom foundation can of course be attached to the bottom in some way and can then consist of a simple attachment with a small mass, not shown. As better seen in frg. 2a and 2b, the float 3 and the bottom foundation - alternatively the bottom bracket - are connected to each other by a rope 7, for example a steel wire. In the embodiment shown, the line is attached to the foundation 5 at one end and at its opposite end it is fixed to a drive package 2 and wound around a first drum included in the drive package, a diving drum 9, which is rotatable about a drive shaft 11. The drive shaft is As shown in the figure, the float at its underside may comprise downwardly projecting struts 13, which can be said to form a frame and at which the shaft 11 is mounted, for example at its ends. On the shaft, in the embodiment shown in these figures, there is also a second drum, an accumulation drum 15, on which a line 17 is partially wound up at its upper end. The line 17 carries at the lower end of the accumulator solder 19. The cylindrical surface of the accumulation drum, on which the line for the accumulation solder is wound, has in the embodiment shown larger diameter than the cylindrical surface of the drive drum 9, on which the line 7 from the bottom foundation 5 is wound. The first-mentioned diameter can be substantially larger than the last-mentioned, such that the ratio between the diameters is in the range 3: 1 to 2: 1.

During the movement of the waves, the distance between the tip 3 and the bottom foundation / bottom bracket 5 varies.

Due to the coupling, the drive drum 9 is rotated through the driving line 7 in a first direction, when the water surface at the fl is raised. In order to be able to turn the drive drum back in a second, opposite direction, when the water surface at the island 3 is lowered, a return mechanism of some kind as required will be described below. The drive drum 9 in turn rotates the drive shaft 11, which is coupled to a generator 21. The coupling between the drive shaft and the generator may or may not, as shown, comprise a mechanical gear 23, which has a gear ratio or gear ratio and which shifts up the drive shaft speed. to a speed suitable for driving the generator.

Hereby one of the rotor parts of the generator 21 is rotatable relative to each other, here for the sake of simplicity referred to as the rotor and stator, for example an internal generator rotor 21 ', cf. fi g. 3b, to rotate in the first direction. The second rotatable part of the generator, for example an external stator 21 ", is fixedly connected to the accumulation drum 15.

Due to the accumulation solder 19, the accumulation drum 15 provides a constant counterforce or a constant counteracting torque on the drive shaft 11, through the coupling between the stator of the generator and the rotor, when the drive shaft is rotated in a first direction of rotation during the ascent of 3. As the torque originating from the drive drum 9 exceeds the counteracting torque resulting from the magnetic coupling between rotor 21 'and stator 21 "in generator 21, upon rotation of these parts relative to each other, more of the line 17 for the accumulation solder 19 is rolled up on the accumulator drum 15. and the excess energy corresponding to this greater torque is thus accumulated by hoisting the accumulating solder.When the surface 3 then begins to rise at an ever lower speed and then decreases at the lowering of the water surface, the rotational speed of the drive shaft 11 and the corresponding generator part 21 'also decreases. the first direction of rotation and then the magnetic coupling across the lug gap in the generator decreases, with the result that the accumulator weight 19 immediately begins to fall, thereby restoring the magnitude of the magnetic coupling across the lug gap in the generator 21. The charge accumulated in the accumulation solder the gene energy thus continues to drive genes atom 21 also at this stage.

As mentioned above, the wave energy is absorbed by the tensile force that arises between fl öte 3 and the bottom foundation 5 or bottom attachment during the rise of the wave. The float follows you in the movements of the road and thereby moves the axis on which the drive drum 11 sits upwards in relation to the bottom foundation Üïiffê 7 dament. A rotational movement occurs which drives the transmission. The vertical movement of the road is converted into a rotational movement, which speed is then shifted up to suit the drive of the generator 21. It is the speed of the vertical movement of the road that determines how much energy can be recovered. The larger the wave, the faster the vertical movement and the more energy can be absorbed. Unlike the energy in the wave, the speed of the vertical movement does not increase with the square of the wave height but follows a more linear pattern. A half meter high wave has an average movement of about 0.3 m! s, a six meter high wave gives about l m / s and a 12 meter high wave about 1.4 rn / s. But the higher the wave, the less impact the 3 damping effect of the float has, which means that the float's vertical movement and driving force increases rapidly, as the wave height rises from a low level to flatten out towards the linear pattern the higher the wave.

A freewheel mechanism or reverse lock 51, see fi g. 5, for the coupling of the drive shaft 11 to the drive drum 9 may be present. The backstop can be designed as a one-way bearing, which is arranged around the drive shaft. When fl ötct 3 rises, the drive drum and the drive shaft are rotated as above in the first direction of rotation by the drive drum hooking into the drive shaft by means of the reverse lock 51. As the float drops, this backstop releases and the drive drum 9 can rotate back, in the second direction of rotation, to roll up the line 7, as will be described below, while the drive shaft 11 is locked against rotation in the other direction of rotation by another backstop 53, which acts between the drive shaft and the strut 13. This second backstop can be arranged at or in the bearing 54 for the drive shaft 11 in the strut. In this way, the drive shaft is always rotated in the first direction of rotation each time the 3 blade 3 rises and it can never be rotated in the opposite second direction of rotation.

If desired, the drive package 2 can be designed so that the drive of the drive shaft 9 of the drive shaft 11 can optionally be disconnected even when rotating in the first direction of rotation. This can be achieved in that the first backstop 51 can be controllable or advantageously by means of a first slip clutch 55, as will be described below. The drive of the drive shaft 11 can then be switched off when the accumulation drum 15 reaches its maximum accumulation level, ie when the accumulation weight 19 has been pulled up so far that it is located close to the accumulation drum. This disconnection of the drive of the drive shaft then ceases when the drive 3 rises again, so that the drive pulley 9 then rotates the drive shaft 11 again. The uptake of wave energy by the wave power plant 1 is thereby limited and overloading of transmission and generator 21 can be prevented when the average wave height exceeds the level at which the wave power plant reaches maximum capacity and cannot handle higher torque over the generator 21. Although the energy uptake can be temporarily removed. connected, the maximum torque still remains over the generator as long as the stored position energy of the accumulating solder 19 can be utilized. Load of generator 21 and transmission stage 23 can thereby be limited while maximum power can be maintained as soon as sufficient average wave height is reached.

The first slip clutch 55 may be located between the one-way bearing / first backstop 51 and the drive drum 9, as schematically shown in fi g. The torque transmitted by the slip clutch between the drive drum and the drive shaft 11 can be controllable in accordance with any suitable electrical signal and in this way the maximum energy absorption level in the system can be set.

The wave power plant and in particular the drive package 2 can thereby be protected against shock loads, which can arise due to the accumulation weight 19 being pulled up to the struts 13 or when a wave breaks or several waves collide right at the wave power plant 1.

The rotation of the drive drum 9 and the rotation of the accumulation drum 15 can also be mechanically interconnected except by means of the magnetic coupling through the generator 21.

This can be accomplished by means of a second slip clutch 25, see Fig. 6, which is used to control how much torque is to be transmitted from the accumulator to the drive drum.

The magnitude of this torque can also be adjustable and controllable. This torque can be used to turn back the drive drum 9 and thereby tension the line 7 to the bottom foundation 5, while the float 3 sinks. The torque can also be used so that the undulating unit 1 does not drift too far away from its bottom bracket due to currents and wind at the water surface. The second slip clutch must in any case be completely disengaged, ie it must not transmit any torque, during the ascending movement of the fl 3 and its transmitted torque during the descending motion of the kan can be suitably adjusted continuously so as not to take more energy than necessary from the position energy stored in the accumulator solder 19 to tension the line 7 to a sufficient degree.

The second slip clutch 25 can, as shown, be arranged in the strut 13, in which the drive shaft 11 is mounted. Gears 27, 29 run towards the edges 31, 33 of the drums, which can then be toothed. The gears are coupled to the input and output shafts of the slip clutch 25 and either of the gears may, if required, be connected via a mechanical gear, not shown, with adapted gear so that the rotational speed of the drive drum 9 is sufficient to roll up the line 7, when the float 3 sinks the fastest. In the embodiment shown, however, the gears 27, 29 are coaxially mounted and are directly connected to the two clutch discs 57 of the slip clutch 25, which are pressed against each other with controllable force, so that when required a torque of desired size can be transmitted between accumulation drum 15 and drive drum 9.

The gear 23, which connects the drive shaft 11 to the generator 21, can provide an upshift of the rotational speed, which may be required especially in the case that the drive drum and the accumulation drum do not have such different outer diameters that they provide a sufficient upshift to achieve a permanent accumulation. of energy and / or to drive the generator 21. The gear may further generally be a variable gear 9 and it may then, for example, as shown as an input stage, comprise a planetary gear 35. The output shaft of this planetary gear, not shown, is then connected to the input shaft, not shown, of a variable gear 37 (CVT), the output shaft of which, not shown, is connected to the first of the generator parts, such as its rotor 21 '. The second part of the generator 21, such as its stator 21 ", and the housing of these gears are rigidly connected to each other and can rotate freely as a unit around the drive shaft 11. The gearing factor between the drive shaft and the first part of the generator is given in this case by the product of the gear and the gear ratio of the variable gear 37.

The electric power emitted by an electric generator depends directly on the speed of the generator. However, high speeds are required to achieve high speeds, which can result in losses, and generally high input torques. A planetary gear 35 as above gives a large fixed gear ratio, can handle high input torques and has good efficiency. The variable gear stage in gear 37 can be used to adjust the speed of the generator according to the current average wave height. Such a variable gear can be, for example, a steplessly variable mechanical gearbox or a hydraulic gearbox.

The drive package 2 can alternatively be made with another accumulation of the energy in the elevation of the water surface, for example as elastically stored energy. No accumulation solder is then required but can, for example, be replaced by a spring, typically a spiral spring 71, see fi g. 3b. Such a spiral spring then has its inner end fixed to the strut 13, while its outer end is attached to the housing of the gear 23 and thus connected to the generator 21, to the other part thereof. Energy can also be stored as a gas pressure as will be described below.

In the embodiment shown in Figs. Zb and 3a, two accumulation drums 15 and associated gear units 23 and generators 21 are connected to the drive shaft 11. An accumulation drum is thus connected to each end of the drive shaft, i.e. the drive shaft is arranged between the two accumulation drums and it is the drive shaft which is mounted in the strut or frame 13. The strut comprises two strut parts projecting downwards from the underside of the fl, each of which comprises a bearing 54 with backstop 53 for the drive shaft 11. Such a structure provides a symmetrical weight load and also a more symmetrical load. due to currents in the water compared to the case where only one accumulator drum with associated generator is used, which is connected to one end of the drive shaft 11.

In addition to moving vertically, the float 3 will also constantly change its angular orientation around a completely horizontal position, which is assumed at a completely calm sea. The drive shaft 11 then also oscillates laterally at all times, which can cause the lines 7, 19 of the foundation and the accumulation solder to fall and rub against each other on the drive drum 9 and the accumulation drums / drums. A tracking mechanism can then be used, which ensures that resp. ropes are wound up in a regular way. One possibility is to use screw grooves 39, 41 on the cylindrical winding surfaces of the drums 9, 15, see Fig. 30. When two accumulation drums are used, the directions of the screw grooves may be opposite, ie one screw groove has a right screw direction while the other has a left screw direction. , in order to maintain to some extent symmetrical load on the wave power plant 1 due to the traction force originating from the accumulation solder 19.

If only one line 7 between the drive drum 9 and the bottom fundamer 5 is used, the point where the force from this line affects the drive drum moves in the axial direction, when the line is more or less rolled up and rolled out. In order to obtain a more symmetrical load in the case of two accumulating drums, the line 7 'can then at its two ends be more or less wound on the drive drum and then run in screw grooves 39 with the opposite screw direction thereon. The middle part of the rope passes down to the foundation 5, where it runs around a pulley, not shown, stored at the upper part of the arn indarnent.

The float 3 may generally be in the form of a plate, which may be elongate. Such an elongate plate can then be placed in a suitable manner, so that it mostly has its longitudinal side facing the wave direction. The width of the float can be adapted to the average wavelength of the waves at sea level, so that the float has a larger width at a larger average wavelength. Various methods can be used to stabilize the position of the float in relation to the wave direction. The rotating movement of the water particles through the waves in combination with the traction force towards the center above the foundation can be utilized by placing fins, not shown, on the underside of the float. Furthermore, the shape of the kan can be adapted. Instead of being located centrally below the plate, parallel to the longitudinal direction of the plate, the drive shaft 11 may be displaced slightly in the direction of the wave direction.

The function of the wave power plant 1 is advantageously controlled by a computerized control system, not shown, which specifically regulates the gear ratio in the variable gear (s) 35, when this is arranged / these are arranged, regulates the transmitted torque of the slip clutch 25 and controls the locking mechanisms for the drive drum 9 and the accumulation drum (s) 15 as well as the drive drum's coupling mechanism 55 to the drive shaft l l. The control system is supplied with energy from a battery, not shown, which is continuously charged by the generator 21, The control system monitors the operation of the waveform using sensors, not shown, in particular different angles of rotation / speeds of the rotatable parts and the electrical power of the generator 21 emitted.

The control system can then control the gear ratio of the variable gear 37 by analyzing data from three sensors. A sensor is mounted in the accumulation drum 15 and constantly tells the control system what degree it has in relation to the direction of gravity. With the help of this, the control system can calculate which revolution the accumulator is on and exactly where it is turning. The turning points for each individual wave period are logged. An algorithm calculates whether the range has a tendency to drift up or down by analyzing the turning points over a period of time. If the bucket ll drives upwards, the transmission is shifted down and vice versa. The length of the time period is determined by the accumulation capacity. The larger the capacity, the larger the time period can be used in the calculation, which entails less adjustments of the torque with which the generator 21 is fed, and thus a more even production of electrical energy.

The second and third sensors measure the electrical power delivered and the speed of the generator / generators 21. These values are recalculated by the control system and show the torque on the generator / generators. The control system uses the value of the torque to continuously regulate the stepless gearing to compensate for the acceleration force of the accumulation solder / solder 19 and the influence of water resistance which arises due to the movements of the spool 3 in combination with the variations of the drive shaft 11 rotational speed. The gear ratio increases as soon as there is a tendency for the torque to increase and vice versa. In this way, the torque with which the generator 21 is fed can be kept almost constant and matched against the value calculated to balance the span of the accumulation solder (s).

The control system also regulates the force transmitted between the accumulation drum 15 and the drive drum 9 via the second slip clutch 25. As the float 3 rises, this slip clutch is disengaged so that all energy is stored as the position energy of the accumulation solder 19. When the lead drops, the slip coupling is regulated to transmit sufficient force fi to partly tension the line 7 to the bottom foundation 5, and partly to prevent the wave power plant 1 from drifting too far away from the bottom foundation due to currents and winds at the water surface. The angular sensor of the drive drum 9 provides the control system with sufficient information to calculate how far the nozzle 3 has driven from a center position directly above the bottom foundation. In this way, only as much power as is needed for the wave power plant to maintain a position not too far away from the center position is transmitted. The transmission in the second slip clutch steals some of the available torque, but this can be regulated automatically using algorithms, which calculate the gear ratio or input from the sensorcma to minimize these and other losses.

When installing the wave power plant 1, the initial position is that the bottom foundation 5 and the accumulation solder 19 are hooked to the parts of the strut 13 with corresponding ropes 7, 17 completely rolled up. The wave power plant is connected to the electrical distribution network and the control system is started. The release mechanism for the drive drum rear lock is set in the locked position according to a signal from the control system, so that the drive drum cannot be released even though the accumulation solder / solder is in its top positions. In the embodiment shown, this means that the slip clutch 55 arranged around the rear lock 51 of the drive drum is set to maximum crane or torque transmission, which is sufficient to support the entire weight of the bottom foundation. The slip clutch (s) 25 between the accumulation drum (s) 15 and the drive drum 9 are completely disengaged so as not to be unnecessarily loaded.

* Torso ïïíí 12 Then the Control System loosens hooks, not shown, which hold the accumulation solder 19 and the bottom foundation 5, whereby the bottom foundation begins to fall towards the bottom of the water collection. The line 7 of the drive drum is then wound out and the drive shaft 11 begins to rotate and drive the generator (s) 21.

The control system regulates the transmission, so that the generators are loaded to the maximum by reading the sensors for the generators' output power and speed. This slows down the fall speed of the bottom foundation as much as possible by the electrical power that is taken out. The float 3 is furthermore suitably equipped with an echo sounder, not shown, which measures the water depth at the place where the installation is made.

The drive drum 9 is equipped with the same type of sensor which is located in the accumulation drum / drum 15 and the control system can thus measure how much of the corresponding line 7 has been rolled out from the drive drum. The control system can use these values to calculate when the bottom foundation 5 begins to approach the bottom. To reduce the impact force on the bottom foundation, the falling speed of the bottom foundation is slowed down by means of the other slip couplings 25. When the bottom foundation reaches the bottom, the drive shaft 11 stops rotating and the accumulating solder / solder 19 begins to fall and continues to drive the generator / generators 21. The release mechanism for the rotation of the drive drum 9 relative to the drive shaft is activated so that the drive drum can rotate in one direction relative to the drive shaft. In the embodiment shown, this means that the slip coupling 55 in the drive drum is set in normal position, which means that the force transmitted by the slip coupling is reduced, so that the force is not sufficient to lift the bottom foundation 5. The control system then switches to operating position.

The external electrical connection of the generator 21 can be achieved without the use of slip rings, brushes and the like. The part of the generator which is fixedly connected to the accumulator drum 15, typically the "stator", contains in an conventional manner electrical windings, cf. 21 "in Fig. 3b, in which electrical voltage is induced by rotation and which are connected to an electric current. risk cable 41, which is partially wound on the accumulator drum parallel to the line 17 of the accumulator solder, see fi g. 4, but closer to the drive drum 9. The electric cable goes from the accumulator drum 15 down to a movable connection contact 43, which can move along the line of the drive drum 7 and is held in the vicinity of the foundation 5. At the connection contact, the electric cable 41 is connected to another electric cable 45, which goes, for example, to a special connection buoy 45. In this way the wave power plant 1 can manage to rotate when the wave direction turns without that ropes and cables become entangled with each other.

Since the first electrical cable 41 is wound on the same drum as the accumulating solder 19, the connecting contact 43 will slide along the line of the bottom foundation with substantially always the same distance below the accumulating solder. This can prevent the accumulation solder and the electrical cables 41, 45 from getting too close to each other.

In an alternative way of energy accumulation, the energy can be stored as a gas smoke in one or ÜWë 13 fl your containers. Such a wave bead installation is shown schematically in Fig. 9. The drive drum 9 here needs to be connected to the drive shaft 11 only via a back groove, compare the back lock 51 in fi g. 5. No struts are required but the drive shaft can be mounted directly in the housing 71 of the gear 23, which here can only comprise a fixed gear such as a planetary gear 35, the generator 21 and a compressor / gas pump 73. The housing is fixedly mounted on the 3 blade 3, such as at its underside. From the compressor / gas pump 73, a gas line 75 goes to the gas container 77, suitably located at or in the tet. The gas containers are also connected to a pressure relief valve 79 and a pneumatic motor 81. On the output shaft 85 of this rotor there are gears 87, which co-operate with teeth on the drive drum 9 31 end 31.

The compressor / gas purge 73 can be a so-called scroll pump and it has a movable part 89, which is fixedly connected to the stator part 21 "of the generator 21, and a part 91 fixed to the housing 71. The drive shaft 53 lock here acts against the housing.

When the drive shaft 11 is rotated by raising the seat 3 in this embodiment, a gas pressure is built up by the scroll pump 73 in the containers 77. This gas pressure corresponds to stored energy. As the gas pressure increases, the resistance to rotation of the drive shaft also increases. Higher waves, which give rise to a faster average rotation of the drive shaft 11, thus build up a higher gas pressure and thus provide a greater counteracting torque between the generator's first 21 'and the second part 21 ". This function replaces the need for stepless gearing between drive shaft and the input shaft of the generator 21.

Since the energy accumulation takes place by building up a pneumatic pressure, the overpressure valve 79 can possibly be used instead of the slip clutch 53 between the drive drum 9 and the drive shaft 11. However, the slip clutch has an advantage in that it protects the transmission against shock stresses. When the drive drum 9 is not rotated by its coupling to the driving line 7, such as when the shaft 3 lowers, it is instead turned back to tension the line by the pneumatic motor 81 rotating and driving the gear 85, which acts against the drive drum flange 31 .

This design of the drive unit 2 can have the following advantages: - No slip coupling is required in the drive drum 9.

- No variable gear (CVT) is needed, because the higher the wave, the higher the gas pressure and torque over the generator 21.

- Possible problems with solder and wires, external electrical cables, acceleration effect, center of gravity, etc. can be completely eliminated or reduced.

- Lower weight, less material.

Can handle shallower installation depth - The housing for gearbox and generator can be made with a smaller diameter than the accumulation drum used in the previously described embodiments.

The same propulsion package 2 as described above can be used in other configurations of the wave ~ 14 power plant as shown in Figs. 7 and 8. Instead of bottom foundations, bottom brackets 61, 63 are attached to the seabed. These bottom brackets are designed as frames or pillars which extend upwards from the bottom and the drive shaft 11 in the driving force package is mounted at the frames. In Fig. 7, two vertical pillars are used, which are completely located below the water surface and extend upwards from the bottom under the fl island 3, and the drive shaft is mounted at these pillars. The frame according to fi g. 8 comprises two vertical pillars, which extend upwards from the bottom over the water surface next to the island. The pillars are connected at the top by a horizontal beam, which is located above the beam and from which struts similar to the struts 13 above project downwards. The drive shaft 11 in the drive package is mounted in these struts.

It can be especially observed, that in the design according to fi g. 8, the energy of the waves is used only when the water surface and the surface 3 fall in contrast to other forms of dehydration, in which energy is only extracted from the waves, when the water surface and the float rise.

In the embodiments described above, the magnetic coupling between the two parts 21 ', 21 "of the generator 21, which are rotatable relative to each other, is used. Energy storage and return drive can take place in different ways. In general, a wave power plant can comprise components as shown in Figs.

. A drive tube 9 is in some way mechanically coupled both to a bottom 3 and to the bottom such as at a bottom bracket 5 ', at least one of these two couplings 7 ", 7"' comprising an elongate member, such as an accessible member, typically a rope or wire, but also a rigid rod can be used in special cases. The drive drum can rotate in two directions shown by the arrows 101, 102. The drive drum, when rotated in one direction, drives a drive shaft 11, which can therefore only rotate in a direction shown by the arrow 103. The drive shaft is mechanically coupled to one the part 21 'of a generator 21, the coupling being symbolically shown at 23. A magnetic coupling is present between the two parts 21', 21 "of the generator, which is used to provide a torque counteracting the rotation of the drive shaft and which drives the generatonis other The second part 21 "of the generator is coupled in some way so that during its rotational movement due to the rotation of the drive shaft it accumulates a part of the rotational energy in an energy storage device 105. When the rotation of the drive shaft is unable to turn the second part of the generator, the energy storage device the second part of the generator to continue to rotate in the same direction as before. The energy stored in the energy storage device can also be used to turn back the drive drum, and for this purpose the energy storage device can be connected to a return drive device 107.

Here, a wave power plant has been described which may have one or more of the following advantages: - The accumulation drum (s) limits the maximum resistance in the system and provides a sharp limit for the torque acting over the generators.

- The accumulation of energy is very simple and efficient and can store energy over a long period of time while the driving force can be kept constant in relation to the average wave height as raw- ííè fi íi Ü? l 5 there during the time interval.

- The wave power plant can be dimensioned to make optimal use of the depth at the installation site for accumulation and to reduce the weight of the accumulation solder.

- The storage of energy is stopped automatically when "the accumulator is full" and this can be achieved without reducing the generated power.

- The scalability is very good and the wave crane can be dimensioned to reach maximum capacity at a selected wave height and dare to have a better degree of utilization of the generator.

- It is not necessary to oversize the entire system in order for it to be able to absorb energy on occasion when the average wave height is significantly higher than normal.

- The float constantly follows you in the movements of the waves, no matter how big the waves are. The force limitation in the drive drum effectively protects the system against shock stresses and overload.

- The driving force is constant in relation to the gear ratio, which makes it impossible to use all types of generators, incl. synchronous alternators, operating at constant or variable speeds.

- Minimal manual efforts during installation, short installation process that generates electrical energy already when the foundation is lowered.

- Mainly simple and robust construction.

- Very high utilization rate of generators and transmission.

- Long service intervals.

Claims (24)

10 15 20 25 30 l 6 PATENT REQUIREMENTS Wave power plant (1) comprising - a te island (3) arranged to float at a water surface of a body of water, and - a propulsion package (2) comprising - - a drive shaft (1 1), - - a first elongate member (7) coupled to the drive shaft (11), - - an electric generator (21) coupled to the drive shaft (11) comprising two rotatable parts (2l ', 21 ") relative to each other, a first and a second part, between which an electromagnetic coupling are present over a hatch gap at least in their mutual movements, and - - an energy accumulation device (19; 71; 77), wherein - fl the island (3), the first elongate member (7), the drive shaft (1 l) and the energy accumulation device (19; 71; 77) are interconnected, so that during wave movement of the water surface, ie during the upward and downward movements of the water surface, the island (3) is caused to rise and fall alternately, whereby the coupling between the first elongate member (7) and the drive shaft (11) causes the drive shaft to rotate in only one direction and thereby drive the generator (21) to generate a electric current, and - the energy accumulation device (l9; 71; 77) is coupled to the drive shaft (11) for accumulating energy at either of the upward and downward movements of the water surface for driving the drive shaft at the other of the upward and downward movements of the water surface, characterized in that the energy accumulation device (19; 71; 77) is coupled to the second part (2l ") of the generator and thereby thereby causing coupling to the drive shaft (ll) via the second part of the generator and the first part (21 ') of the generator and the air gap provides a torque which counteracts the rotation of the drive shaft (ll) as it rotates and drives the first part (21 ') of the generator, - so that the second part (2l ") of the generator rotates in a first direction through the coupling to the drive shaft (1 l) via the air gap and the first part (21') of the generator, when the drive shaft (1 1) torque exceeds the opposing torque and the energy accumulation device (19; 71; 77) thereby accumulates energy through its connection to the second part (21 ") of the generator, the first and second parts of the generator (21 ', 21") simultaneously rotating in a rich relation to each other, and - so that the second part (21 ") of the generator of the energy accumulation device (19; 71; 77) is driven to rotate in the same first direction substantially, when the torque of the drive shaft (11) does not exceed the counteracting torque, whereby the first and second parts of the generator (2l ', 21 ") are caused to continue to rotate in the same direction in relationship to each other. Wave power plant (1) according to Claim 1, characterized in that the energy accumulation device (19; 71; 77) is directly connected to the second part (21 ") of the generator, Éïšïiiš (FF-fl 17 - so that the second part of the generator (21 ") rotates in the first direction through the coupling to the drive shaft (1 1), when the torque of the drive shaft originating from the coupling to the elongate member (7) at some of the upward and downward movements of the water surface exceeds the counteracting torque and the energy accumulation device (19 71; 77) thereby accumulates energy through its connection to the second part (21 ') of the generator, and - so that the second part (21 ") of the generator of the energy accumulation device (19; 71; 77) is driven to rotate in the same first direction in mainly at the other upward and downward movements of the water surface. Wave power plant (1) according to one of Claims 1 to 2, characterized in that the drive shaft (1 1) is rotatably mounted at the tet blade (3) and in that the first elongate member (7) is connected at one end to a fixed point. . Wave power plant (1) according to one of Claims 1 to 2, characterized in that the drive shaft (1 1) is rotatably mounted in a device (61; 63) fixedly fixed to the bottom of the water collection and in that the first elongate member (7) at an end year connected to the float (3). Wave power plant (1) comprising a fl island (3) arranged to fl surface at a water surface of a body of water, a drive shaft (1 l) rotatably mounted at the fl beam (3) or at a device (61) fixedly attached to the bottom of the body of water ; 63), a first elongated member (7), which is partly connected to a fixed point at the bottom of the water collection resp. at the shaft (3), on the one hand, an electric generator (21) coupled to the drive shaft (11) is connected, which comprises two parts (21 ', 21 ") rotatable relative to each other, and an energy accumulation device ( 19; 71; 77), wherein the float (3), the first elongate member (7), the drive shaft (11) and the energy accumulation device (19; 71; 77) are interconnected, so that during wave movement of the water surface the float (3) is caused to alternate they rise and fall, whereby the coupling between the first elongate member (7) and the drive shaft (11) causes the drive shaft to rotate in substantially only one direction of the upward and downward movements of the water surface and thereby drive the generator parts (2l ', 21 ") to rotate relative to each other in a first direction and generate electric current, characterized in that the energy accumulation device (19; 71; 77) is arranged to drive the parts of the generator substantially at the second of the upward and downward movements of the water surface. (21 ', 21 ") to rotate in the same order direction in relation to each other and thereby generating electric current with the same polarity as when the drive shaft (1 1) drives the generator parts (2l ', 21 "). Wave power plant (1) according to one of Claims 1 to 5, characterized in that the energy accumulation device comprises a counterweight (19) arranged as an accumulation solder so as to approach each of the upward and downward movements of the water surface also upwards and thereby toe larger. position energy and that the coupling between the fl island (3), the first elongate member (7), the drive shaft 10 15 20 25 30 553? Cfšlffš l 8 eln (11) and the counterweight (19) are arranged so that in said second of the upward and downward movements of the water surface the counterweight (19) moves downwards and thereby drives the parts (2l ', 2l ") of the generator to rotate in relation to each other. Wave crane (1) according to claim 6, characterized in that the coupling between the float (3), the first elongate member (7), the drive shaft (1 1) and the counterweight (19) is arranged so that at said either of the water surface upward and downward movements the counterweight (19) moves upwards a distance which is greater than the distance which the fl island (3) moves in the vertical direction. Wave power plant (1) according to one of Claims 1 to 5, characterized in that the energy accumulation device comprises a resilient or elastic device (71) for elastic storage of energy. Vágkra fi plant (1) according to one of Claims 1 to 5, characterized in that the energy accumulation device comprises a container (77) for storing energy in the form of a gas pressure. Wave power plant (1) according to claim 9, characterized in that the energy accumulation device comprises a compressor / gas pump (73), which has a moving part directly connected to one of the parts of the generator (2l ', 21 "). 11. ll. Wave power plant (1) according to claim 10, characterized in that the compressor / gas pump (73) is a scroll pump. Wave crane (1) according to one of Claims 1 to 5, characterized in that the energy accumulation device comprises an accumulation drum (15) rotatably mounted on the drive shaft (11), an accumulation weight (19) arranged as a counterweight and a second elongate means (17) for coupling movements of the counterweight (19) to drive the accumulation drum (15) to rotate, the drive shaft (1 1) being coupled to rotating the first part (21 ') of the generator and the accumulation drum (15) being coupled to rotating the generator second part (21 "), the generator 21 generating current when its second part (2l") is rotated relative to its first part (2l ') and at the same time provides a torque counteracting this rotation, whereby the parts (21', 21 ") of the generator can be made to rotate relative to each other at a substantially constant speed. Wave power plant (1) according to one of Claims 1 to 5, characterized in that the energy accumulation device comprises an accumulation drum (15) rotatably mounted on the drive shaft (1 1), an accumulation weight (19) arranged as a counterweight and a second elongate (17) means for coupling movements of the counterweight (19) to drive the accumulation drum (15) to rotate, the accumulation drum (15) being fixedly connected to the second part (2l ") of the generator and the coupling between the second elongate member (17). ) and the accumulating drum (15) causes the accumulating weight (19) to move upwards as the drive shaft (1 1) rotates, which increases the position energy of the accumulating weight (19) and provides a limited counter-force fi against the rotation of the drive shaft (1 1). Wave power plant (1) according to claim 13, characterized in that when the drive shaft (11) does not rotate, the accumulation weight (19) moves downwards and causes the accumulation drum (15) to rotate. Wave power plant (1) according to one of Claims 1 to 5, characterized by a drive tube (9), which is mounted for rotation about the drive shaft (1 1) in a single direction and is coupled to the first elongate member (7) for causing the drive drum (9) to rotate at said either of the upward and downward movements of the water surface and thereby also drive the drive shaft (11). Wave power plant (1) according to claim 15, characterized in that the first elongate member (7) is a flexible member, and that a coupling (55) is arranged between the energy accumulating device (19; 71; 77) and the drive drum (9). to rotate the drive drum (9) during said second upward and downward movements of the water surface, so that the flexible member (7) is kept stretched. Wave power plant (1) according to claim 16, characterized in that the flexible member (7) is fixed at one end at a fixed point, and at its other end is more or less wound on the drive drum (9), the wave power plant ( 1) comprises a slip coupling (55) acting between the accumulator drum (15) and the drive gear (9) for transmitting torque from the accumulator drum (15) to the drive drum (9) during said second of the upward and downward movements of the water surface. the flexible member (7) between the drive drum (9) and the bottom is tensioned, in order thereby also to prevent the wave power plant (1) from being moved away along the water surface. Wave power plant (1) according to claim 15, characterized in that the energy accumulation device comprises an accumulation drum (15) and a counterweight (19) and that the second elongate member is a flexible member (17), which at a lower end is attached to the counterweight ( 19) and at its upper end is more or less wound on the accumulating drum (15), the diameter of the winding surface of the accumulating drum (1S) being larger than the diameter of the winding surface of the drive drum (9). Wave power plant (1) according to claim 18, characterized in that the coupling between the drive drum (9) and the first part (21 ') of the generatonis comprises a gear (23) for gearing up the rotational speed of the drive drum (9). Wave power plant (1) according to claim 15, characterized in that the first elongate member comprises a flexible member (7), that the winding surface of the drive drum (9) is divided into two adjacent segments, that the segments have helical grooves (39 ) with opposite screw directions, that the wave power plant (1) comprises a bottom foundation (5) or bottom bracket with a freely rotatable pulley therein, and that the first visible member (7) with its two ends is more or less wound on the screw grooves of the two segments ( 39) and at an intermediate portion runs around the pulley located at the bottom, whereby a substantially symmetrical connection between fl island (3) and bottom foundation (5) or bottom fastening can be achieved. Wave power plant (1) according to one of Claims 1 to 20, characterized in that it comprises two electric generators (21) connected to the drive shaft (11) and two associated energy accumulation devices (19; 71; 77), the first elongate member (7) is connected to the drive shaft (11) at a location between the two pairs of electric generator and associated energy accumulation device. Wave power plant (1) according to one of Claims 1 to 20, characterized in that the coupling between the drive shaft (1 1) and the first part (21 ') of the generator comprises a gear (37) with a variable gear ratio for adjusting the rotational speed of the first generator. del (21 '). Wave power plant (1) according to claim 22, characterized in that the energy accumulation device comprises a counterweight (19) and that a control system is provided for controlling the gear ratio of the gear (37) to also adapt the speed of the counterweight (19) to its downward movement, so that the counterweight (19) in the ascending and descending movements of the fl island (3) moves within an adapted or suitable vertical span. Wind power plant according to one of Claims 1 to 3 and 5, characterized in that the energy accumulation device comprises an accumulation drum (15) and a counterweight (19) connected by a flexible member (17) and in that an electrical cable for electrical connection of the generator is provided. device, which goes from the generator (21) to the accumulator drum (15) 15 connected to the generator and is partially wound on it, which from there goes (41) to a non-floating part (43) slidable along the first elongate member (43) , to which it is fixedly connected, whereby the slidable part (43) is kept at a constant distance below the counterweight (19), and which extends (45) from the slidable part (43) up to the water surface for further connection to an electric load, which allows the wave power plant (1) to be rotated in the horizontal plane, such as when the direction of the water waves changes, without the electrical cable 20 winding into the visible member (17).