WO2005065024A2

WO2005065024A2 - Method and apparatus for converting sea waves and wind energy into electrical energy

Info

Publication number: WO2005065024A2
Application number: PCT/IL2004/001186
Authority: WO
Inventors: Haim Morgenstein
Original assignee: Haim Morgenstein
Priority date: 2004-01-01
Filing date: 2004-12-30
Publication date: 2005-07-21
Also published as: IL159691A; WO2005065024A3; IL159691A0

Abstract

Energy converter, consisting of a buoy that floats on the surface of the water and maintained in a fixed horizontal position, to serve as a floating reference platform; a water impervious outer sleeve with a cylindrical inner surface with a first wing at its wave side, such that the sleeve is pivoted to the buoy; a generator, housed within the sleeve in a longitudinal manner, that comprises magnetic field generation (MFG) means and a rotor. The MFG means or the rotor are stationary components that are maintained in a fixed position with respect to the buoy. The rotor or the MFG means are rotatable and have an axis of rotation that coincides with the longitudinal axis of the stationary component. The rotatable component is angularly displaced by the sleeve, relative to the stationary component, as a result of the first wing that is angularly displaced bywaves impacting the first wing, such that the relative displacement generates electrical power.

Description

METHOD AND APPARATUS FOR CONVERTING SEA WAVES AND WIND ENERGY INTO ELECTRICAL ENERGY

Field of the Invention

The present invention relates to the field of energy production. More particularly, the present invention relates to an energy converter unit ^hereinafter sometimes simply 'converter') for converting wave motions Dccurring in a body of water and wind into electrical energy.

Background of the Invention

Currently used electrical energy production technologies still make massive use of coal and fuel fossils, which are used for generating steam. The generated steam imparts rotation movement to a turbine, the shaft of which is mechanically coupled to a rotor of an electrical generator, which, upon rotation of its rotor, outputs electrical energy the magnitude of which is a function, among other things, of the rotation speed of the rotor and the size of the generator. However, coal and fuel fossils have to be transferred from the coal mines and oil wells, respectively, to the location of the power stations consuming the coal/fuel fossils. Usually, power stations are very remote from the coal mines and oil wells, and, therefore, the coal/fuel fossils have to be transferred to them, usually a long distance. Coal and fuel fossils are usually transported by trucks and ships. Oil is also bransferred by pipes. Such transportation is expensive and gives rise to the final cost of the electrical energy that is produced that way. In addition, using coal and fuel fossils greatly pollute the environment. The high costs involved in producing electrical power and the pollution caused by its production, encourage the developnient and use of other alternative options. Desalination plants are known as electricity-consuming facilities. Often, desalination facilities are constructed near the sea. Therefore, in many cases, electricity has to be transferred to them from a land electricity power station which is often located a long distance from the desalination facility. Therefore, an extra electricity infrastructure must be used for allowing the transfer of the electricity to the desalination facility. However, the extra electricity infrastructure gives rise to the final price of the desalinated water. Therefore, it would be beneficial to provide an effective energy converter that would be located near the desalination facility, that would be self-sustained and that would not require a massive electrical infrastructure or long electrical wires for providing the electrical energy required by the desalination plant.

Consequently, many methods and apparatus have been proposed to produce electrical energy in ecologically clean and inexpensive ways. Some of them have been successful. For example, the potential energy of water reservoirs is utilized, in some places in the world, for driving into rotation a hydro-turbine which is coupled to an electrical generator that converts the rotational motion into electrical energy. In such apparatus, water from highly placed water reservoirs are allowed to flow downwards inside pipes and through valves, for driving a hydro-turbine into rotational motion, whereby to cause an electrical generator to generate electrical power.

Many proposals have been made for utilizing the energy of ocean waves to generate power, but heretofore none has proved successful. Early attempts at harnessing the rhythmic motion of waves for operating pumps involved the use of floats or flaps moving on the water surface relative to a substantially stationary part. But the equipment proposed failed to extract more than a small proportion of the available energy, largely due to a failure to appreciate the mechanism involved in the transfer of wave energy in water bodies, with consequent failure to design the moving parts of the apparatus in such a way as adequately to respond to the wave motions. Many prior art proposals comprise the utilization of the vertical motion of the surface of the sea, which results from the presence of waves, for producing the vertical motion of a rod, which is then converted into rotational motion for driving the shaft of a generator. Such systems are described in, e.g., JP 23065200, JP 22285946, WO 01/06118 and in WO 02/075151.

US 4,406,586 discloses a buoyant structure, having an upper portion in the region of wave action and a lower section below said region. The buoyant structure includes a vertical shaft that is impelled to rotate in one direction regardless of the direction of the movement of the impelling fluid.

JP 091444642 discloses a structure that includes a shaft that rotates in one direction as a result of a turbine that is impelled to rotate by vertical motion of waves.

GB 1,482,85 and GB 1,571,790 disclose an apparatus for extracting energy from the wave motion occurring in a body of water.

However, most of the technologies that use waves-driven energy converters involve complex structures, and/or said converters have been found to be inefficient or impractical. Often, the conversion of the wave energy is not enough complete. Another drawback of said technologies is that the energy converter they provide is incapable of self-adjustment to the characteristics of the sea waves. For example, the efficiency of such an energy converter might be relatively high for some amplitude and frequency of the sea waves, but significantly deteriorate under other operating conditions. Therefore, it is another object of the invention to provide a method and an apparatus for efficiently and inexpensively converting the energy of sea waves into electrical power.

It is yet another object of the invention to provide an energy converter unit that has a simple structure.

It is a further object of the invention to provide an energy converter unit that sustains high operating efficiency irrespective of the condition of the sea waves.

It is a still further object of the invention to provide an energy converter that exploits the energy of the wave to a nearly complete degree. It is a still further object of the invention to provide an energy converter unit that utilizes essentially all the energy contained in the sea waves.

It is a still further object of the invention to provide an energy converter unit capable of self-adjustment to the normally varying conditions of the sea waves.

It is yet another object of the invention to provide an energy converter unit capable of exploiting wind energy.

Other objects and advantages of the invention will become apparent as the description proceeds

Summary of the Invention

In the following description, it is assumed that the energy converter of the invention substantially floats on the water, generally in the sea but broadly in any body of water in which significant wave motion occurs, such that most of it resides underneath the surface of the body of water and in such a position that one side thereof (hereinafter, "the wave side") is exposed to the impact of the waves and, optionally wind, while the other side (hereinafter, "the shore side") faces the shore and is exposed to the back flow generated by the waves' breaking on the shore. Correspondingly, the energy converter is asymmetric in that respect.

By 'generator' is meant herein to an electric generator. As known in the art, an electric generator is a device used to convert mechanical energy into electrical energy, bjr causing an electric conductor, like a copper wire, to move through a magnetic field. Movement of the electric current in the magnetic field will result in a current flowing (the current being induced) in the electric conductor, whereby to convert the mechanical energy of the moving electric wire into an electric energy. One factor that affects the electric output of a generator is the number of the turns of the electrically conducting wire. The wounded wire and the shaft on which it is wounded are known in the art as 'rotor'. Electricity is generated by the generator, by causing the rotor to rotate in a magnetic field generated by magnetic field generating (MFG) means.

As noted hereinabove, the rotation of a rotor in a magnetic field induces electric current. However, electric current can also be induced by causing the MFG means to rotate around a stationary rotor. Therefore, by 'stationary component' is meant hereinafter to the MFG means or, depending on the implementation approach, to the rotor being stationary.

By 'rotatable component' is meant hereinafter to the rotor that is permitted to rotate in the magnetic field generated by the stationary MFG means in accordance with the impacting waves, or, depending on the implementation approach, to the MFG means that is permitted to rotate around the stationary rotor in accordance with the impacting waves. According to a first approach, the MFG means is the stationary component and the rotor is the rotatable component, whereas according to a second approach, the rotor is the stationary component and the MFG means is the rotatable component, in order to allow the generation of electric current in the rotor, as described hereinabove, in both approaches. With respect to the first and second above-described approaches, the buoy serves as a floating reference platform, and by 'stationary component' is meant the MFG means, or the rotor (depending on the application) being in substantially a fixed position with respect to the buoy.

Accordingly, the present invention provides an energy converter, which comprises: a) a buoy that substantially floats on, or near the surface of, the water and substantially maintained in a fixed horizontal position, to serve, among other things, as a floating reference platform; b) a water impervious, outer sleeve (hereinafter simply 'sleeve') having a cylindrical inner surface and having a wave engaging projection (called hereinafter 'first wing', or, sometimes, just 'wing') at its wave side, said sleeve being pivoted to said buoy; c) a generator, housed within said sleeve in a longitudinal manner, which comprises magnetic field generation (MFG) means and a rotor, wherein: cl) the MFG means, or, alternatively, the rotor, is a stationary component that is maintained essentially in a fixed position with respect to said buoy; and c.2) the rotor, or, alternatively, the MFG means, is a rotatable component that has an axis of rotation coinciding with the longitudinal axis of said stationary component, said rotatable component being angularly displaced by said sleeve, relative to said stationary component, as a result of said first wing being angularly displaced by, and accordance with, waves impacting said first wing, the relative displacement generating electrical power.

According to a first approach, the stationary component is the MFG means of the generator, and the rotatable component is the rotor of the generator. According to this embodiment, the energy converter further comprises: a) a rotatble cylinder, housed within the sleeve, normally positioned at the bottom of said sleeve (thanks to the gravity force) and tends to return to said normal position if displaced from it; b) means for permitting said rotatable cylinder to roll but not to slide over said cylindrical inner surface of said sleeve. The rotation of said rotatable cylinder being transferred to said rotor to generate electrical power; and wherein,

The generator is normally positioned at the bottom of the sleeve (thanks to the gravity force), aligned with said rotatable cylinder and tends to return, together with said cylinder, to said normal position if displaced from it, whereby to maintain the MFG means substantially stationary with respect to the buoy.

With respect to the rotational displacement of the sleeve relative to the buoy, by 'pivot' is meant that each one of the pivots of the sleeve is contactlessly supported by the buoy, in contradistinction to what may be called an 'ordinary' pivot that rotates in a recess formed in a supporting body while being in direct contact with the recess. More specifically, each one of the pivots of the sleeve is supported by the buoy by use of two cables that are secured, on one hand, to the buoy, and, on the other hand, to the pivot. As a result of the angular displacement of the sleeve relative to the buoy, the cables wound on the pivots of the sleeve, causing the pivots to be linearly displaced from their original, or normal, position, which is the position of the pivots in which the cables are unwounded to expose their fullest length. However, since the maximum angular displacement of the sleeve is about 130° , the linear displacement of the pivots does not interfere with the proper functioning of the energy converter. The use of 'hung' pivots is beneficial because, this way, the pivots operate in a frictionless manner, which render them very resistant to wear and to the harsh conditions of sea water.

The means for permitting said rotational member to roll but not to slide over said cylindrical inner surface of said outer sleeve preferably comprise:

1) an inner gearing formed longitudinally and peripherally in or solid with said cylindrical inner surface of said outer sleeve, preferably extending over an angle greater than the maximum angular displacement of said outer sleeve and more preferably of at least 180° ;

2) an outer gearing formed in or solid with the outer surface of said rotatable member, structured so as to mesh with said inner gearing. Said inner gearing and said outer gearing should mesh over a long enough longitudinal extension of said outer cylinder and said rotatable member, that they permit said rotatable member to roll over the inner surface of said outer sleeve but not to slide over it. The peripheral extension of said inner gearing should be such that it should mesh with said outer gearing in all the angular positions of said outer sleeve that may be caused by the wave motion, as will be explained hereinafter.

The mass of the generator and the mass of the rotatable member, to which the generator is coupled, normally maintain said generator and said rotatable member in a normal or rest position that is at the bottom of said outer sleeve, and tend to return said generator and rotatable member to said normal position if displaced from it. In a preferred embodiment of the invention, a first weight (or sometimes called hereinafter 'generator weight'), housed by said sleeve, is rigidly affixed to, and support, the generator so as to increase said force (i.e., said tendency to return to normal position. Said first weight is externally affixed to the generator, such that said first weight, under the influence of gravity, constantly functions to bring the generator to its normal position, with the rotatable member, where the aforesaid wing is essentially in horizontal position, whenever said generator is displaced from it.

The first (generator's) weight is allowed to become displaced with the rotatable member, and guiding means is provided for the first weight to support it during its displacement. The guiding means is preferably a sliding rail, or a sliding channel, that is rigidly affixed, or formed, respectively, to/in the inner surface of said outer sleeve. The sliding rail/channel resides on a plane that is substantially parallel to the plane on which the line of roll of the rotatable member resides. In addition, the rotor of the generator is mechanically coupled to the rotational member. The generator's weight supports the generator and allows it, by its slide, to be displaced along with the rotational member, keeping both aligned to one another, by being keyed to the same shaft.

As noted above, in order to generate electricity, a relative rotational displacement must be obtained between the rotor and the MFG means. What characterizes this invention, among other things, is that the relative rotational displacement between the rotor and the MFG means of the generator is obtained in the following way: on one hand, the slide of the first weight, and therefore of the generator (MFG means and rotor), is such that their radial orientation with respect to a fixed point laying on the rotation axis of the sleeve, is maintained along the sliding line. On the other hand, the rotor is driven into rotation movement by the rotatable member who is driven by the outer sleeve (by means of the inner and outer gearing, as described above) into rotational movement, thus obtaining the relative rotational displacement required for the generation of the electric energy.

Preferably, a second weight (hereinafter 'sleeve weight') is rigidly attached to the bottom of the outer sleeve and on the inside thereof, to assure that said sleeve is always returned to the angular position in which said second weight is at its lowest point. This position will be called hereinafter the normal (angular) position of said outer sleeve, which normal position is preferably such that the aforesaid wing extends horizontally, outwardly, from the top of said outer sleeve. The generator, generator mass and rotational member (both relevant to the first approach for being displaceable), generator mass and the sleeve weight are located longitudinally, along the interior of the outer sleeve, such that the overall weight thereof is evenly distributed along the interior of the sleeve, so as to maintain the converter balanced.

The wave-engaging member (i.e., the first wing), is adapted to be angularly displaced by the energy of the sea waves and angularly swings up and down, in accordance with the movement of the sea waves, such that it is in a horizontal rest position (sometimes called hereinafter 'normal position') in the absence of waves and is lifted, viz. angularly displaced with respect to the horizontal, whenever a wave impacts on it. The angle (a) by which it is so displaced depends, primarily and among other things, on the energy of the impacting wave. After the energy of the wave dissipates, the wing returns to the horizontal or rest position, mainly thanks to the angular moment exerted on the outer sleeve by the sleeve weight (i.e., the second weight). As the wing alternately becomes lifted and returns to the rest position, the outer sleeve alternately rotates clockwise or counterclockwise. The wing should be as light as permitted by the required mechanical strength. The second weight function to return the sleeve to its normal position, if displaced from it, whereas the wing functions to absorb the waves' energy. Therefore, the wing should be light enough, comparing to the second weight, so that it will not ill affect the functionality of the second weight.

The wing should therefore be hollow and preferably have a structure that will be described hereinafter. It should be triangular or circumscribed in a triangle, the base of which is located at the point at which the wing is joined to the outer sleeve. Such a shape of the wing improves its mechanical strength, since the impact of a wave will subject the wing to a moment that is maximum at its base, but it also improves the transfer of energy from the wave to the outer sleeve. In a preferred embodiment, said wing comprises a series of sealed and light-weighted tubes, each of which has a diameter that is smaller as the tube is farther from the cylindrical body of the outer sleeve. The resulting wing profile helps to convert the force, resulting by the generally horizontal and vertical movement of the sea waves, into a force, acting on the bottom of the wing to swing it about the axis that is defined by the pivot connections of said sleeve to the buoy.

Another aspect of the weight of the wing relates to the efficiency of the wing, and therefore of the energy converter unit, in various kinds of waves.

More specifically, the optimal rotational displacement of the wing is 90° , and it should ideally be maintained for every impacting wave, because a smaller displacement (e.g., 60° ) would result in low electrical output of the converter, whereas a larger displacement (e.g., 120° ) would result in excess of water being spilled over the wing, meaning that the energy embodied in the excess water is not converted to electricity. The optimal angular displacement of the wing is maintained by utilizing a dynamically mass arrangement, the functionality of which is described hereinbelow.

The buoy is provided with two flexible mooring ties that are transversely spaced from one another and connected to a respective anchor fixed on the sea bottom. The mooring means inhibit, or at least minimize, swing of the buoy. The buoy includes a water impervious, empty portion, such as to impart to it the buoyancy required for it to float. The outer sleeve, being water impervious and pivoted to the buoy, contributes to such buoyancy, but the masses of the rotatable member and generator and the aforesaid generator weight and sleeve weight detract from it.

Thanks to the buoyancy of the impervious sleeve, the force, which is exerted by the components therein (generator, weights, self-mass, etc), on the pivots, cables or rotor's shaft (depending on the application) is tolerable such that no special fastening/securing/fixing means are required in this regard, and there is no excess wear of the pivots thereby.

On the sea side, the buoy has preferably an upper surface so shaped as to direct the waves towards the wing, for capturing as much as possible of the wave energy. On the shore side, the buoy has a lower surface shaped to repel water flowing back from the shore, so as prevent it from interfering with the incoming waves.

When a wave lifts the wing and correspondingly rotates the outer sleeve, different phenomena may occur. The rotatable member may remain at its equilibrium position, viz. at the bottom of the outer sleeve, and therefore rotate as the outer sleeve rotates. If the outer sleeve rotates in the counter clockwise direction, the motor cylinder will rotate in a counter clockwise direction as well. This will be called the first limit phenomenon. In the second limit phenomenon, the rotatable member may be initially lifted without rotating as the outer sleeve rotates, viz. remain in the same relative position with respect to said sleeve, and then, after said sleeve has completed its rotation, the rotatable member may return to its equilibrium position, viz. to the bottom of the outer sleeve, and in so doing will rotate. In the second limit phenomenon too, the rotatable member rotates counter clockwise if the outer sleeve has rotated counter clockwise and vice versa.

Whether the first or the second limit phenomenon occurs, depends on the structural parameters of the outer sleeve and of the rotatable member and on the angular speed and amplitude of the outer sleeve's rotation caused by each wave. What most often occurs, however, is an intermediate phenomenon which is a compromise between the two limit phenomena: the rotatable member is lifted with the rotation of the outer sleeve, but not to its highest theoretical position, rotates somewhat while it is displaced from its equilibrium position, and returns completely to the equilibrium position after the rotation of the outer sleeve has ceased. However, the overall rotation of the rotatable member is the same in both limit phenomena for a given rotation of the outer sleeve, and therefore it is not necessary to establish how close the intermediate phenomenon is to the first or second limit phenomena. In addition, thanks to the masses of the rotatable member and generator, and to the generator's weight (the first weight), the intermediate phenomenon will be closer to the first limit phenomena. Put otherwise, the generator, together with its weight (the generator's weight) and the rotatable member will tend to remain in the close vicinity of the equilibrium position as the outer sleeve swings about its normal position.

In a preferred embodiment of the invention, the energy converter is provided with means ('dynamic mass arrangement') to maximize the efficiency thereof by self-adaptation to changes that occur in the waves' parameters, particularly frequency and amplitude, or, as may be said, to the wave regime. According to said embodiment of the invention, the energy converter comprises a first and a second containers, adapted to be filled with liquid (e.g., water) and emptied, the mass of said first container, including the mass of the liquid therein (if not empty), is added to the mass of the sleeve's weight to exert additional moment to return the sleeve, and therefore the first wing, to its rest, or normal, position, whereas the mass of the second container, including the liquid therein (if not empty), is subtracted from the mass of the sleeve's weight. The containers are housed within said outer sleeve and are connected to one another by two conduits, 'fill' and 'return' conduits, so shaped and located that if the first container is full and the second container is empty, while there is a series of low waves, each wave exceeding a given low threshold, one conduit (i.e., the 'fill' conduit) will transfer liquid from the first container to the second container, whereby to expand the frequency response of the converter by decreasing the moment of inertia of the outer sleeve, and/or decreasing the mass added to the mass of the sleeve's weight, whereas if the second container is full and the first container is empty, while the waves are high, the other conduit (i.e., the 'return') will return the liquid from the second container to the first container, whereby to effect the opposite effect. The return conduit is so shaped and connected to the second container in such a way that whenever the first wing is displaced by at least 90° , and returned substantially to its normal position, the liquid in the second container will spill to the first container. By maximizing the efficiency of the energy converter is meant that the first and second containers are emptied or filled, depending on the waves' energy, such that the wing is displaced by the optimal displacement angle

(i.e., 90°), or about that angle. Since normally the average energy of waves changes slowly, the converter unit is capable of adapting itself to these slow changes fast enough such that the wing would be displaced by the optimal displacement angle, or tend to reach an angle close to the optimal angle.

According to a preferred embodiment, the first container substantially lays on a longitudinal line of the sleeve passing substantially through, or near, the sleeve's weight, and the second container may, or may not, lay on a plane passing through the axis of rotation of the sleeve and the sleeve's weight. According to an aspect of this embodiment, the second container lays on the axis of rotation of the sleeve. According to another aspect of this embodiment, the second container lays on inner side of the sleeve, opposite to the first container.

According to a preferred embodiment of the invention, the outer sleeve further comprises a mechanical stopper for assuring that the first wing will not turn the converter unit upside down when being impacted by high waves, by harnessing the mass of the generator, the first (generator's) weight and the mass of the rotatable member, to exert, thereby, a moment on the outer sleeve, via the stopper, that is a function of the difference between the actual angular displacement of the sleeve ta\ and a value

a _engage » wherein 90° < a_engage « 180° and a > _mgage .

The stopper is rigidly affixed with a first end to the inner side of the outer sleeve, in such a way that when the angular displacement of the first wing meets the condition a = c _mgage , the opposite end of the stopper is brought in contact, i.e., engaged, with the generator, and, if the angular displacement of the first wing exceeds a_engage , the stopper will displace the generator, its weight, and the rotatable member from their normal position. Should this happen, the mass of the generator, its weight and the mass of the rotatable member will effect additional force that will help returning the first wing to an angular displacement smaller than _engage .

It should be noted that, when using the first and second containers, their conduits and/or the stopper, their locations in the interior space of the outer sleeve must be such that the converter unit as a whole is balanced.

According to one preferred embodiment of the invention, the first wing comprises a plurality of cells (hereinafter 'wing cells'). Each wing cell has a wide opening that is directed to a direction substantially perpendicular to the plane of the wing, such that, whenever the wing is in a rest, normal or horizontal, position, the wide openings of the wing cells face the water side and are fully soaked in the body of water. Each wing cell includes also a narrower, elongate, passage (hereinafter 'vent opening'), that connects the interior of the wing cell to the atmosphere in the opposite side of the wing. Therefore, whenever the wing is in horizontal position, the water occupy the interior spaces of the wing cells, 'pushing' the air locked in the interior of the wing cells through the respective vent opening, whereby to allow to the interior of each wing cell to be filled with water. The wing cells are preferably arranged so as to be circumscribed in a triangle, in a similar manner like the 'pipes' based wing. That is, the wing cells are arranged such that the closer are the cells to the sleeve, the larger is their interior space, and therefore, the larger is their water-holding capacity. The wing cells are preferably structured as a honeycomb.

Each wing cell includes a one-way valve, which can be either in "CLOSE" state or in "OPEN' state, which opens whenever water pushes air from the interior of the wing cell to the atmosphere, through the vent opening, and closes whenever the wing returns to its normal, horizontal, position, whereby to effect a 'suction' phenomenon, according to which the water of the dissipating wave, which previously lifted the wing (when impacted on it), draw, or pull, the wing in a downwards direction. As a result of the suction phenomenon, the Degree of Freedom (DOF) between the wing and the waves impacting it is significantly reduced, whereby to fully exploit each individual wave while in it's 'downwards' motion, as well as while in its 'upwards' motion.

Likewise, and for obtaining a similar 'suction' phenomenon with respect to the buoy, the distal end of the lower surface of the buoy, which faces the shore side, is longitudinally curved to form an opening that is directed generally downwards and towards the wave side, and it comprises, in longitudinal manner, a plurality of cells (hereinafter 'buoy cells') that function in a similar manner as the cells of the first wing. The buoy cells function in the following way: normally, the buoy is in horizontal position, and the curved end is positioned substantially underneath the surface of the water, and therefore, water fully occupy the interior spaces of the buoy cells.

Now, a wave impacting on the upper surface of the buoy will exert on surface a force that will act to lift the curved end above the water surface. However, thanks to the water that is locked in the interior spaces of the buoy cells, a counter force, in the form of suction force, is exerted by the water on the curved end, whereby to stabilize the buoy in horizontal position. Like the wing cells, each buoy cell includes a wide opening, a narrow elongate passage and a one-way valve, the function of which is described in connection with the wing cells. The buoy cells are preferably structured as a honeycomb.

The energy converter unit may further comprise a second wing assembly for utilizing wind energy for helping elevating the first wing, for increasing the electrical output of the generator. The second wing assembly preferably comprises: a) a second wing, to be elevated by wind and stalled in synchronization with the waves; b) a wing trailing edge supporting means, externally affixed to the upper surface of the first wing (i.e., the surface of the first wing opposite to the surface impacted by the waves), for supporting the trailing edge of the second wing when in a rest or in stalled position; c) a pivot supporting means, for pivotly supporting the leading edge (the edge facing the wave side) of the second wing, said means permitting the angle (λ ), between the first and the second wings, to change in accordance with the condition of the waves and wind; and d) pivotable flap, said flap comprises an airfoil and a hydrofoil sections which form a fixed angle (77), to the distal end of said hydrofoil section is connected a flap weight, to be displaced from the rest, or substantially vertical, position by an impacting wave, to expose said second wing to the wind, and thereby, to cause said second wing to be elevated and to lift the first wing, which is connected to said second wing by said pivot supporting means, and to conceal said second wing from the wind, in gradual manner and depending on the angle of the first wing relative to the horizon, where, when said second wing is in vertical position, said airfoil section fully concealing said second wing from the wind, resulting in said second wing being stalled, and exerting a force on said first wing to help returning said first wing to its rest, or horizontal position when the impacting wave collapses.

According to an aspect of the invention, the ('flap') angle 77 « 180° . In addition, the mass of the flap's weight is to be determined in accordance with other factors, such as the dimensions and masses of the other components/elements of the converter, the gap between the first and the second wings, the relationship between the energy of the waves and the wind, etc.

The second wing is longitudinally located along the first wing, and it is structured and shaped to resemble a typical wing of an airplane and is intended to function as such. The second wing is preferably structured to be as light as possible (a first option), such as by using light and resilient materials (metal and/or plastics) and, optionally, by leaving hollowed cavities, or empty spaces, therein, to utilize as much as possible of the elevation force. However, if desired, the mass of the second wing can be made heavy to assist returning the first wing from its optimal, or near optimal, position to its rest position (the second option). Most probably, the weight of the second wing will be a compromise between the two options.

According to a second approach, the rotor is the stationary component and the MFG means of the generator is the rotatable component. According to this embodiment, the energy converter further comprises: a) for each of the two opposing sides of the sleeve, hollowed pivot, through which a corresponding rotor's shaft passes in a frictionless manner;

b) sealing means, between each pivot and the rotor's shaft passing through it, for preventing water from entering the sleeve; c) fastening means, for rigidly fastening the rotor's shaft to the buoy, for inhibiting angular displacement of the rotor with respect to said buoy; and d) anchoring means, for anchoring the generator to the inner surface of said sleeve, whereby to allow relative angular displacement between said rotor and said MFG means of said generator, as a function of the angular displacement of the wing, and therefore of the sleeve. The relative angular displacement generates electrical energy. Optionally, each one of the pivots is pivotly supported by the buoy, for allowing rotational displacement of the sleeve relative to the buoy.

Of course, the dynamic mass arrangement (i.e., the second and first containers, including the conduits that connect them to one another) and the sleeve weight can be used, mutatis mutandis, in a system conforming to the second approach.

If desired, or required, depending on the circumstances, the outer sleeve may further include basic, simple, circuitry for initial stabilization of the electricity produced by the energy converter unit. The stabilized electricity may be further handled (e.g., the voltage doubled) in the place where it is needed.

If desired, or required, an energy system can be obtained by serially 'chaining', or linking to one another several energy converter units, such as the energy converter unit of the present invention. Such an energy system will yield an electrical output that is substantially the sum of the electrical output of the individual energy converter units.

Brief Description of the Drawings Fig. 1A is a schematic side view of the energy converter unit of the present invention, in a rest, or normal, position in the absence of waves; Fig. IB shows a perspective view of the outer sleeve and wing of the energy converter unit of the invention;

- Fig. 1C schematically illustrates an exemplary mooring means for mooring the converter shown in Fig. la; Fig. 2 schematically shows the wing of the converter in an intermediate displacement condition; - Fig. 3A is a schematic vertical cross-section showing a rotatable member, gearing means and stopper of the converter;

- Fig. 3B is a partial perspective view of the rotatable member shown is Fig. 3A;

- Fig. 3C shows the generator supported by the first (generator's) weight, according to the first approach of the present invention; Fig. 4 schematically shows the dynamic mass arrangement, according to a preferred embodiment of the invention; Figs. 5A and 5B schematically illustrate two typical positions of the dynamic mass arrangement shown in Fig. 4;

- Fig. 6 schematically illustrates an upper view of an exemplary energy system consisting of twelve energy converter units;

- Figs. 7A, 7B and 7C show three exemplary positions of the stopper relative to the generator; Figs. 8 A and 8B schematically illustrates two exemplary arrangements of the generator, according to the first approach of the present invention; Fig. 9 schematically illustrates exemplary symmetrical arrangement of the dynamic mass arrangement, sleeve's weight and generator and rotatable member; Fig. 10 schematically illustrates an exemplary arrangement of the generator, according to the second approach of the present invention; Fig. 11 schematically illustrates a second structure of the buoy and wing, that is based on 'suction' cells; and Figs. 1 A, 12B and 12C demonstrate the second wing in three typical positions, relative to the first wing, according to the present invention.

Detailed Description of Preferred Embodiments

Fig. la schematically illustrates an energy converter unit according to a first preferred embodiment of the present invention, in rest condition, viz. in the absence of waves. Buoy 105 is maintained in a fixed horizontal position with respect to the sea floor 111 by a mooring ties that consists, in this embodiment, of a flexible cable 104 (also 104a, Fig. lc), e.g. of metal, attached at one end 114 (also 114a, Fig. lc) to said buoy and at the other end 113 (also 113a, Fig. lc) to an anchor 103 (also 103a, Fig. lc). Numeral 111 indicates the bottom of the sea and numeral 109 the surface of the sea, in the absence of waves. The two mooring ties maintain the buoy perpendicular to a general or main direction of the waves, to assure uniform operation of the energy converter.

Outer sleeve 101 is pivoted to the buoy 105, by 'contactless' pivotes, about an axis indicated at 112 in Fig. IB and is freely rotatable about said axis and with respect to said buoy. Said axis is so located that the bottom of outer sleeve 101 is slightly lifted from the upper surface 115 of buoy 105. Numeral 108 indicates one of the 'contactless' pivots that rotatably connects outer sleeve 101 to buoy 105. Each one of the pivots of the sleeve is supported by the buoy by use of two cables that are secured, on one hand, to the buoy, and, on the other hand, to the pivot. For example, pivot 108 is supported by cables 116 and 117. As a result of the angular displacement of the sleeve relative to the buoy, cables 116 and 117 wound on the pivot of the sleeve, causing the pivots to be linearly displaced from their original, or normal, position, which is the position of the pivots in which the cables are unwounded to expose their fullest length. The use of 'hung' pivots (e.g., pivot 108) is beneficial because, this way, the pivots operate in a frictionless manner, which render them very resistant to wear and to the harsh conditions of sea water.

Other components of the energy generator, while necessary, may be conventional and therefore need not be described as they are well known to skilled persons. They are: a generator, a mechanical connection between the rotatble member and the generator, whereby they have a common shaft and the rotatble member drives the generator into (intermittent) rotation, and electrical connections between the generator and outside apparatus which use or store the electricity produced. Said electrical connections may not be needed if the energy generator includes electricity using or storing apparatus, for instance lighting installations, storage batteries, chemical apparatus, or the like. If such electrical connections are needed, they must be such that they can pass through the water and reach electricity using or storing apparatus on shore or on embarkations or floats. If desired, or required, depending on the circumstances, the outer sleeve 101 may further include basic, simple, circuitry for initial stabilization of the electricity produced by the energy converter unit. The stabilized electricity may be further treated (e.g., the voltage doubled) in the place where it is exploited or needed.

Wing 102, which is light-weight, is mechanically affixed to outer sleeve 101 in the longitudinal dimension, viz. along all or a sufficient length of said outer sleeve. Being light and empty, it has a substantial buoyancy and is capable of floating on the sea waves. Wing 102 is adapted to be driven in response to the energy of waves, and is constructed so as to exploit as much as possible of the energy. As shown in Fig. 1, wing 102 consists of a plurality of sealed tubes (102a), which are larger the farther they are from outer sleeve 101. In this embodiment said tubes are cylindrical, which is preferred but not essential, and the smaller is their diameter the farther the tube is from the outer sleeve, or, as might be said, the tube cross-section, in this embodiment its diameter, decreases from the base to the tip of the wing.

The unique structure shown in Fig. 1 is advantageous in two aspects. Firstly, the wing floats on the water, and as a wave arrives and the water rises, the buoyancy of the wing is translated into a force lifting the wing, whereby to turn outer sleeve 101 about its axis 112. Secondly, the shape of the wing and buoy helps guiding an impacting wave in such a way that the energy embodied in the wave is fully exploited to angularly lift the wing to produce electricity, as described herein.

Two surfaces of buoy 105 contribute to the exploitation of wave energy for the purposes of the present invention. Buoy 105 includes an upper surface (106) and a lower surface (107) that are inclined with respect to the horizon. Upper surface 106 generally faces the sea side, viz. the front of the incoming waves, for directing the waves towards wing 102, as shown schematically by reference numeral 106a, for capturing as much of the wave energy as possible. Lower surface (107) generally faces the shore side for repelling backflow waters streaming from the shore, as shown schematically by reference numeral 107a, and preventing said waters from interfering with the incoming waves. Thanks to the upper surface (106), an additional portion of the wave energy is exploited for generating a rotary moment on wing 102.

Fig. 2 shows an exemplary motion of the wing. Wing 102 is shown in two different positions (rest, or normal, position 102/1 and lifted position 102/2). The first position (102/1) is the rest, or equilibrium, where the stabilizer weight, schematically shown at 203, is in the lowermost location (2O3/1) directly below pivot 108, and wing 102 is essentially in horizontal position (102/1). Thanks to the energy embodied in wave 201 which impacts on wing 102, wing 102 is moved to a second position (102/2), which forms a displacement angle >0 with respect to said first position. Wing 102 is a light-weight structure, and, therefore, only a small portion of the energy of wave 201 is used for elevating/rotating wing 102. The remaining portion of the wave's energy is converted into potential energy by displacing outer sleeve 101 and its stabilizer weight (i.e., the sleeve weight, being the second weight) 203 by the same angle α, and the generator, including the generator's weight (i.e., the first weight) and rotatable member 301 (Fig. 3) by an angle that would be zero if the phenomenon hereinbefore called the first limit phenomenon occurs, and it would be α if the phenomenon hereinbefore called the second limit phenomenon occurs, and may generally be intermediate between zero and α. No matter what occurs, the rotatable member will rotate and actuate the generator, to an extent that depends on the angle by which the outer sleeve has rotated, and this in turn will depend on the energy of the wave, so that the energy embodied in waves such as wave 201 is fully exploited for generating electrical energy. As each wave 201 impacts on wing 102, the process described repeats itself, causing outer sleeve 101 to alternately turn clockwise and counterclockwise. Sleeve weight 203 is shown in Fig. 2 in its rest, or normal position 203/1 and in its lifted position 203/2, where it has acquired potential energy that is converted into electricity after the energy of the impacting wave dissipates.

Stabilizer, or sleeve, weight 203 is an integral part of cylindrical structure 101 and it is incapable of moving relative to the circumference 204 of sleeve 101. The mass of stabilizer 203 and its distance from the center of rotation 112 guarantee that sleeve 101 will always return to its equilibrium position even in a stormy sea. Stabilizer 203 will always exert a rotational moment on outer sleeve 101 if its center of gravity 205 is displaced from the normal, lowest, position, i.e., if its center of gravity does not lie on vertical line 206.

Because wing 102 absorbs energy from the waves, leaving relatively flat sea surface in the opposite (207) direction, energy converter unit 200 can be utilized as a dynamic wave breaker. By "dynamic" is meant that whenever there are no waves (in a calm sea), wing 102 floats in its rest (horizontal) position, unaffectmg the natural propagation of small ripples on the surface of the sea, and whenever there are waves, wing 102 rises in accordance with the energy of the waves, so as to absorb as much of the wave energy as possible, leaving relatively flat surface in the opposite direction.

As described hereinabove, the generator includes a housing that contains a stationary component and a rotatable component, such that a relative angular displacement therebetween causes the generator to generate electric energy.

According to the second approach, the stationary component is the rotatable component (MFG means) of the generator, and the rotatable component is the rotor of the generator. An arrangement that exemplifies this notion is shown in Figs. 3 and 8.

Fig. 3A shows schematic view of a rotatable member, according to an embodiment of the invention. Rotatable member 301 is housed in and supported by outer sleeve 101 and has an axis of rotation 306 that is parallel to the axis of rotation 112 of outer sleeve 101 (see Fig. IB). Thanks to the gravitational force that is exerted on the rotatable member 301, said rotatable member 301 is, in the absence of waves, in an equilibrium position in outer sleeve 101, as schematically shown in Fig. 3A. In the equilibrium position, the center of gravity of rotatable member 301 is on vertical line 206, which lies on the vertical plane passing through axis 112 of outer sleeve 101 (see Fig. IB).

Rotatable member 301 is provided with outer, longitudinal gearing 302 which meshes with inner longitudinal gearing 303 of outer sleeve 101, which has a sufficient angular span to guarantee said meshing engagement in all angular positions that sleeve 101 may assume when wing 102 is displaced by an impacting wave. Due to the meshing gears 302 and 303, rotatable member 301 will always rotate in the direction opposite to the rotation of sleeve 101, by an angle depending on the ratio of the diameter of said sleeve to the diameter of said rotatable member irrespective of whether what occurs is one of the two aforesaid limit phenomena or an intermediate phenomenon. In case of an intermediate phenomenon, every time wing 102 and sleeve 101 are caused by a wave to rotate by an angle that depends on the energy of the wave, rotatable member 301 always tend to maintain or resume its equilibrium position, wherein its center of gravity is on line 206, and consequently rotates and actuates the shaft of the generator.

Fig. 3C schematically illustrates a side cross-section showing the generator and the first (i.e., generator's) weight, according to a preferred embodiment of the present invention. Rotatable member 301 (Fig. 3A) and generator 307 are coupled to one another by means of a common shaft (not shown). More specifically, rotatable member 301 is coupled by the shaft to the rotor of generator 307. Generator 307 is rigidly affixed to, and supported by, slidable weight 308, the sliding of which on the inner side of sleeve 101 is guided by guiding means, preferably sliding rail or sliding channel, formed on/in the inner side of sleeve 101. A transverse cross- sectional view of the sleeve is shown in Fig. 8.

Mechanical stopper 304 is provided to limit the angular displacement of outer sleeve 101 to a preferred angle _engage which conforms to the

condition 90° < a « 180° . Under extreme wave conditions (i.e., stormy sea), wing 102 may surpass the preferred angle cc_engage and thus the system may potentially become unstable. The functionality of stopper 304 is described in more details in the description relating to Fig. 7.

Fig. 4 schematically illustrates a dynamic mass arrangement for optimizing the operation of the energy converter, according to a preferred embodiment of the present invention. The energy carried by sea waves are usually distributed on a spread spectrum, meaning that consecutive waves can be frequent and have small amplitude, or they can be spread from one another and have large amplitudes, etc. Therefore, in order to exploit the present invention to its fullest, it is required to automatically and dynamically adapt the system to the varying wave's conditions under which the system works. In order to allow this feature, a dynamic mass arrangement is utilized, in which mass is transferred, or shifted, from/to the center of outer sleeve 101 to/from the periphery thereof, thereby changing the inertia of said outer sleeve 101. Transferring the required mass is implemented in the present invention by utilizing a first container and a second container, between which liquid is exchanged automatically in accordance with the parameters of the sea waves. Because the optimal displacement angle of wing 102 is α = 90° , as described before, the exchange of liquid can be optimized such that the wing will be angularly displaced by a = 90° substantially for any kind of wave that impacts wing 102.

More particularly, the dynamic mass comprises a first container (401), a second container (402), a Zig-Zag piping (403) and a return pipe (404). Whenever the sea waves are high (indicative of high energy) and have low frequency, the liquid concentrates in first container 401, whereby to increase the moment of inertia of outer sleeve 101, for adapting the inherent frequency response of the system to the high energy waves, viz. lowering said inherent frequency. In contradistinction, whenever the waves are low (indicative of low energy) and have high frequency, the liquid concentrates in second container 402, whereby to decrease the moment of inertia of cylindrical structure 101, for adapting the inherent frequency response of the system to the low energy waves, viz. increasing said inherent frequency. The transfer of liquid between the two containers occurs automatically. Zig-Zag piping 403 draws the liquid from the first container 401 and conveys the liquid to second container 402. Return pipe 404 returns the liquid from second container 402 to the first container 401. The components of the dynamic mass arrangement are stationary with respect to each other and with respect to outer sleeve 101. Their operation will be better understood from Figs. 5A and 5B.

Fig. 5A schematically illustrates in more details the Zig-Zag piping shown at 404 in Fig. 4. The dynamic mass arrangement, generally indicated at 500, is shown in Fig. 5A in the equilibrium position of outer sleeve 101. Pitch angle β of Zig-Zag piping 403 determines the minimal level of the energy of a wave that will cause liquid 501 to flow from first container 401 to second container 402. The greater is β , the greater the energy level (of a wave) must be to cause the transfer of the liquid 501 from container 401 to container 402.

There are two extreme conditions relating to the liquid content in containers 401 and 402: a. In the first extreme condition container 401 is full with liquid while container 402 is empty. This condition results from one or more energetic waves. Being full of liquid, container 401 adds additional inertia, or damping, moment to outer sleeve 101, to allow the system to respond to the normally slowness of energetic waves; and b. The second extreme condition is that container 401 is empty while container 402 is full of liquid. This condition results from a series of very low-energy and frequent waves. Being empty, container 401 contributes no additional inertia, or damping, moment to outer sleeve 101, and so allows the system to quickly respond to the frequent weak waves.

Of course, the system is capable of automatic adaptation to any wave's condition, by filling container 401 up to the extent that the system as a whole will have an optimized performance under specific waves' condition. Should the specific waves' conditions change, liquid will be added to container 401, or transferred from container 401 to container 402, depending on the waves' condition. It should be noted that the level of liquid in container 401, at a given time, depends on the last several consecutive waves impacting on wing 102.

Referring to Fig. 5a, low-energy waves will cause wing 102 to moderately swing clockwise and counterclockwise, causing liquid to be transferred from container 401 to the first pipe segment 502 and from pipe segment 502 to pipe segment 503, etc., until the liquid reaches the last pipe segment (507) and is poured into container 402. The more consecutive low- energy waves hit wing 102, the more liquid will be transferred to container 402.

In the position shown in Fig. 5A, in which the 'Zig-Zag' piping is in the equilibrium position of outer sleeve 101, viz. in the absence or before the impact of a wave, said piping comprises a number of first parallel segments at an angle β from the horizontal (e.g. segment 502), the first of which is connected to the first container 401 and the last to the second container 402, a number of second parallel segments that are nearly horizontal (e.g. segment 505), at an angle γ from the horizontal, and several, essentially parallel, segments, such as segments 503 and 506 which connect the first to the second parallel segments and vice versa. The operation of the Zig-Zag piping can be illustrated by considering one cycle of operation, by which is meant a first stage where wing 102 is forced by a wave to a position where > 0° , followed by a second stage in which wing

102 is in equilibrium position where a = 0° . In said first stage of said cycle of operation, in the equilibrium position of outer sleeve 101, a certain amount of liquid flows from container 401 to pipe segment 502 (see Fig. 5B) and some liquid will also reach pipe segment 503. In said second stage of said cycle of operation, a certain amount of liquid flows from pipe segment 503 to pipe segment 505. Another cycle of operation will cause liquid to be transferred from segment 505 to be transferred to segment 508, and so on, until the liquid is poured into container 402. If low-energy waves keep hitting wing 102 for sufficiently long time, container 402 will be eventually filled with liquid, and container 401 will be empty.

Referring to Fig. 5B, should energetic waves impact on wing 102, the liquid stored in container 402 will slide back to container 401, along return pipe 404. It should be noted that, after a sufficiently long time, the Zig-Zag piping is filled with liquid. The difference between low-energetic waves' condition to energetic waves' condition is that in the low-energetic waves' condition container 402 is allowed to be full of liquid, whereas in the energetic waves' condition, container 402 is always kept empty, as liquid, which is poured via segment 507 into container 402, is immediately poured back to container 401, along return pipe 404, in order to keep container empty.

Fig. 6 schematically illustrates an upper view of an exemplary energy conversion system layout, according to the present invention. In order to increase the electrical energy potential, a system may be used, which comprises a plurality of energy converter units such as energy converter unit 200. An exemplary width W of an energy converter unit (200) is about 10 meters. An exemplary number of energy converter units is 12 unit 200/1 to 200/12), and an exemplary overall length 'L' of the 'chain' of energy conversion units is about 250 meters. The dimensions and number of converter units are shown in Fig. 6 only for illustration purposes. Actual figures will conform to the nature of the seabed, expected energy of waves, the distance from the shore to the energy conversion system 'S' (e.g., a few of hundreds of meters), and the water depth in the installation location, in order to fully exploit the prevailing geographical conditions in the installation location, in terms of electrical output power. Fig. 7 schematically illustrates three positions of the mechanical stopper 304 shown in Fig. 3. Stopper 304 is rigidly affixed to the inner side of the sleeve 101, such that there cannot be any movement of the one relative to the other. The dotted lines 1 to 4, inclusive, are for orientation purpose. In Fig. 7A, stopper 304 is shown in its normal position, where wing 102 is in its rest, or normal position, as are generator 307 and the generator's weight 308. In Fig. 7B, stopper 304 is shown in its 'engagement' position, in which a wave having an energy, which will be called 'engage energy', causes wing 102 to be displace such that a = _engage . In the engagement position, stopper 304 is brought in contact, viz. engaged, with generator 307. If a wave impacts on wing 102 with an energy larger than the 'engage energy', wing 102 will be displaced such that > a_mgage , causing stopper

304 to displace generator 307 from its lower, equilibrium, or normal, position, as shown in Fig. 7C. Being displaced to a higher location, the mass of generator 307 will act, via stopper 304 and together with sleeve weight 203, to return sleeve 101 to the normal position that is shown in Fig. 7A. sleeve weight 203 is not shown in Fig. 7A because it is located longitudinally beyond generator 307 and weight 308. Fig. 8A schematically illustrates a partial transverse cross-sectional view of the sleeve, according to one preferred embodiment of the present invention. Rotatable member 301 is provided with outer, longitudinal gearing 302 which meshes with inner longitudinal gearing 303 of outer sleeve 101, which has a sufficient angular span to guarantee said meshing engagement in all angular positions that sleeve 101 may assume when wing 102 is displaced by an impacting wave. Shaft 802 connects rotatable member 301 to the rotor (not shown) of generator 307, to cause it to rotate relative to the stator (not shown) of generator 307. Generator 307 is supported by, and rigidly affixed to weight 308 (the first, or generator's weight), which is slidable in sliding channel 801. Sliding channel 801 can be replaced by any suitable guiding means. For example, it can be replaced by a fixed sliding rail, in which case generator weight 308 should have a channel adapted to be slid on the sliding rail.

In order not to exert stressing forces on shaft 802, which may result from the sliding of weight 308, and therefore of generator 307, in sliding channel 801, on one hand, and the rotation of rotatable member 301, on the other hand, additional rotatable member (301a) and gearing element (303a) can be used, for alleviating the aforesaid stress. Of course, arrangement 800a is only an exemplary arrangement for the generator and rotatable member, as other arrangements othereof can be used, for example the arrangement shown in Fig. 8B.

Fig. 8B schematically illustrates another partial transverse cross-sectional view of the sleeve, according to another preferred embodiment of the present invention. In Fig. 8B arrangement 800b includes two generators, 307/ 1 and 307/2, and two respective generators' weights, 308/1 and 308/2, and only one rotatable member 301, located, for symmetry purpose, between the two generators 307/ and 307/2. Shafts 802 and 802a connect rotatable member 301 to the rotors (not shown) of the two generators 307/1 and 307/2, respectively, and cause them to be angularly displaced with the respective stator s (not shown) of the generators, to produce electricity. Reference numerals 801/1 and 801/2 denote the sliding channels, in which weights 308/1 and 308/2, respectively, slide, carrying generators 307/1 and 307/2, respectively. Reference numeral 303 denotes gearing means that causes rotatable member 301 to roll, whereby to cause shafts 802 and 802a to roll, whereby to cause the respective rotor to rotate to produce electricity.

The first and second containers, and the conduits connecting therebetween, are not shown in Figs. 8A and 8B, because these figures are meant to show only the relationships between the generator 307, its weight 308,

Fig. 9 schematically illustrates exemplary relationships between the various components residing inside the sleeve, according to one preferred embodiment of the present invention. A guiding line in arranging the components in sleeve 101 is that symmetry exists with respect to the deployment of the overall mass of the components along the longitudinal direction of sleeve 101. It is important that the symmetry is kept because symmetry will keep the sleeve, and therefore the energy converter unit, balanced. Nevertheless, the components (i.e., the generator, first and second weights, first and second containers, including their conduits, and the rotatable member, including the first and second gearing means) can be arranged in many different ways, all conforming to the 'symmetry' guiding line.

Referring to Fig. 9, second container 903 is rigidly affixed essentially along the axis of rotation of sleeve 101. Second container 903 may be divided into several chambers, such as chamber 903/1, 903/2, etc., to eliminate a situation where the sleeve would be internally exposed to forces that might be exerted by liquid that is longitudinally moving from one side to the opposite side of container 903 as a result of, e.g., a storm. Of course, there is a connecting passage between each two adjacent chambers, for allowing equalizing the amount of liquid in the different chambers. First container 901 is shown divided into two chambers, 901/ and 901/1, which can be interconnected by a conduit, or not. The two conduits interconnecting between first container 901 and second container 903 are not shown. However, since the dimensions and mass of these conduits are negligible, that is, in comparison to the dimensions and masses of the other components in sleeve 101, they can be located substantially everywhere in the interior of sleeve 101, without ill affecting the functionality of the energy converter unit.

Reference numeral 904 denotes the location of the 'generator-rotatble member' arrangement. For example, the generator and the rotatable member can be arranged in location 904 according to the arrangement 800a or 800b, as shown in Figs. 8A and 8B, respectively.

As explained hereinabove, the longitudinal order of the various components in sleeve 101 can be different than the one shown in Fig. 9, provided that the symmetry is kept in the longitudinal manner.

Fig. 10 schematically illustrates an exemplary arrangement of the rotatable and stationary components of the generator, according to the second approach. According to this approach, the stationary component is the rotor (symbolically marked by dotted line 1001) of generator 1002, and the rotatable component is the MFG means which fixedly resides inside generator 1002. According to this embodiment, the energy converter further comprises: a) for each of the two opposing sides (1003 and 1004) of sleeve 101), hollowed, pivot (1006 and 1007), through which a corresponding extension (1008 and 1009) of the rotor's shaft (1010 and 1011) passes and extends (1012) beyond the full length of the elongate pivot in a frictionless manner; b) for the two opposing sides (1015 and 1016), or panels, of buoy 100O, passages 1013 and 1014, through and by which the corresponding elongate pivots 1006 and 1007 extend and supported, respectively, as described hereinabove (i.e., by making each pivot a 'contacless', or hung', pivot). Each one of the shaft extensions 1012 and 1018 is rigidly supported by a fastening means, such as fastening means 1017 (tfxe fastening means relating to shaft extension 1018 is not shown), for rigidly fastening the extension of the rotor's shaft to the buoy, whereby to inhibit angular displacement of rotor 1001 with respect to buoy 1000; and

c) anchoring means, such as anchoring means 1019, for anchoring generator 1002, and therefore the MFG means inside it (not shown), to the inner surface of sleeve 101, whereby to allow relative angular displacement between rotor 1001 and the MFG means of generator 1002, which occurs whenever wing 102, and therefore sleeve 101, is angularly displaced by a wave impacting wing 102.

The MFG means, which is internally anchored to the housing of generator 1002 that is rigidly connected to sleeve 101 by connecting means 10O5, angularly 'moves' together with sleeve 101, whereas rotor 1001 is rigidly connected to buoy 1000 to inhibit any angular displacement thereof. Therefore, the angular displacement of wing 102, relative to buoy 1000, is directly translated to the same angular displacement between the MFG means of generator 1002 and rotor 1001, whereby to help maximizing the electrical output of the energy converter.

Of course, if the second application is adopted, the stopper (304) is irrelevant.

The first arrangement, according to which the rotatable component is the rotor and the stationary component is the MFG means, as exemplified in

Fig. 8, is not an optimal arrangement because some portion of the mechanical energy of the waves is wasted due to the existence of a Degree of Freedom (DOF) between the generator/rotatable member and the outer sleeve. That is, some portion of the waves' energy is wasted every time the generator and the rotatable member are displaced from the normal position. However, using the second arrangement, as exemplified in Fig.

10, substantially eliminates that problem.

Fig. 11 schematically illustrates the converter unit, according to another preferred embodiment of the present invention. Fig. 11 shows a side view of the converter unit shown in Fig. 10, in which the connecting means

1005 are shown rigidly connecting the generator housing 1002 to the inner side of the sleeve 101 such that the axis of rotation of generator 1002 and the axis of rotation of sleeve 101 coincide. Connecting means 1005 can be cables or rigid plates, or any suitable rigid structure that supports and maintain generator 1002 in its centric position in the sleeve 101.

In addition, Fig. 11 introduces a wing (1101) that has a different structure than wing 102. Wing 1101 comprises a plurality of wing cells, such as wing cells 1102, which form a honeycomb -like structure. Each wing cell has a wide opening (1103) that is directed to a direction substantially perpendicular to the plane of the wing, such that, whenever wing 1101 is in a rest, normal or horizontal, position, the wide openings of the wing cells face the water side and are fully soaked in the body of water. Each wing cell includes also a narrower, elongate, passage (a 'vent' opening, 1104), that connects the interior 1105 of the wing cell to the atmosphere (1106) in the opposite side of the wing. Therefore, whenever wing 1101 is in horizontal position, the water 'pushes' the air locked in the interior (1105) of the wing cells through the respective vent opening 1104, whereby to allow to the interior 1105 of each wing cell to be filled with water. Only four wing cells are shown in Fig. 11 (1102), for simplicity. The honeycomb like wing cells are preferably arranged in a similar manner like the pipes from which wing 102 consists. That is, the honeycomb-like wing cells are arranged such that the closer are the cells to the sleeve, the larger is their interior space, and therefore, the larger is their water-holding capacity.

In addition, wing 1101 includes, per each wing cell, a one-way valve, such as one-way valve 1107. Reference numeral 1107/c and 1107/o denote valve 1107 in "CLOSE" and "OPEN" states, respectively. One-way valve 1107 opens whenever water pushes air from the interior 1105 of the cell to the atmosphere 1106, through the vent opening 1104, and closes whenever wing 1101 returns to its normal, horizontal, position, whereby to effect a 'suction' phenomenon, according to which the water of the dissipating wave, which lifted wing 1105 when impacted on it, draw, or pull, wing 1105 in a downwards direction. As a result of the suction phenomenon, the Degree of Freedom (DOF) between wing 1105 and the waves is significantly reduced, whereby to fully exploit each individual wave in it's 'downwards' motion, as well as its 'upwards' motion.

Likewise, and for obtaining a similar 'suction' phenomenon with respect to the buoy 1000, the distal end 1108 of the lower surface of the buoy 1000, which faces the shore, is generally curved towards the wave side, and it longitudinally comprises a plurality of buoy cells 1109, such as buoy cell 1109/i, i=l to n, 'n' being the number of the cells, (a cross-section of which is shown in Fig. 11), which function in a similar manner as wing cells 1102. The wide opening 1110 of each buoy cell is directed generally towards the wave side. Buoy cells 1109 function in the following way: whenever the buoy is in normal, horizontal, position, curved end 1108 is positioned mostly underneath the surface llll of the water, and therefore, water fully occupy the interior spaces of cells 1109. Now, a wave impacting on the upper surface 1112 of buoy 1000 will exert on surface 1112 a force that will act to lift curved end 1108 above surface llll of the water. However, thanks to the water that is locked in the interior spaces 1113 of the cells 1109, a counter force, in the form of suction force, is exerted by the water on the end 1108, whereby to stabilize buoy 1000 in horizontal position.

Fig. 12 schematically illustrates incorporation of an elevation platform (herein 'second wing') to the energy converter unit, according to another preferred embodiment of the present invention. According to this embodiment, the energy converter unit further comprises a second wing for harnessing the energy embodied in the wind, by translating the force of the wind to an elevation force that will be translated into additional force acting to angularly displace the first (i.e., waves) wing. Wing assembly 1200 comprises: wing 1201, wing trailing edge supporting means 1202, pivotable flap 1205, to which a flap weight is connected (1207), and pivot supporting means 1209, for pivotly supporting the leading edge (the edge facing the wave side) of wing 1201. Pivtable flap 1205 comprises an airfoil and a hydrofoil sections 1205/A and 1205/H, respectively, which form a fixed angle η . Wing 1201 is longitudinally located along the wing 102, and it is structured to resemble a typical wing of an airplane and is intended to function as such. Because the aerodynamics involved in the functioning of a wing is known, no theoretical description thereof is given herein with respect to the functionality of wing 1201. Wing 1201 is preferably structured to be as light as possible, such as by using light and resilient materials (metal and/or plastics) and, optionally, by leaving hollowed cavities therein, to obtain as much elevation force as possible. However, if desired, the mass of wing 1201 can be made heavy enough to return wing 102 from its optimal position to its rest position. Most probably, the weight of wing 1201 will be a compromise between the two options.

Referring to Fig. 12A, it shows the energy converter unit in a rest position, where the body of water is calm and there are essentially no meaningful waves. In the rest position, wing 1201, which always faces the wave side, is generally spaced from the first wing (102 or 1101, depending on wing structure) in a parallel manner. Pivot supporting means 1209 maintain pivot 1203, about which wing 1201 is pivotable, in a fixed position with respect to the first wing (102 or 1101). Wing trailing edge supporting means 1202 support the 'shore side' end (trailing edge) of wing 1201 to maintain wing 1201 substantially in horizontal position while wing 1201 is in a rest position (i.e., when the body of water is calm). Thanks to the wing trailing edge supporting means 1202 and to the pivotable supporting means, the angle λ between the first (the wave) and the second (wind) wings is permitted to change in accordance with the waves impacting the first wing (102 or 1101) and the wind impacting the second wing 1201. Wave 1206 is a wave approaching the energy converter unit.

Because waves are generated by the wind and tend to coincide with the wind's direction, the direction of the wind is often substantially identical to the direction of the waves. Likewise, lacking waves usually means that either the wind is very weak, or there is there is no wind at all. Sometimes, the conditions of the waves and wind are such that they interfere with each other. That is, there might be a situation where waves act to lift wing 102, whereas, the wind acts simultaneously to lower wing 1201. Therefore, the operation of the two wings must be coordination. The required coordination is provided by flap 1205 that is pivotable about pivot 1208 that is secured to the wave side edge of wing 102 (or 1101). The hydrofoil section resides fully, or partially (depending on the angle of wing 102/1101 with respect to the horizon), underneath the surface of the water.

Whenever the wings 102 (or 1101) and 1201 are at rest, as shown in Fig. 12A, flap weight 1207 pulls hydrofoil section 1205/H downwards, whereby to bring the airfoil section 1205/A to a position where airfoil section 1205/A conceals wing 1201 from the wind (if a wind exists), to prevent relative velocity between the wing 1201 and the air surrounding it, and, thus, to prevent the wind from exerting an elevation force, and other forces that might exist due to the wind, on the second wing 1201.

However, in the event of a wave impacting the first wing 102 (or 1101), the airfoil 1205/A changes position whereby to fully expose the second wing 1201 to the wind, allowing relative velocity to exist therebetween, which will act to elevate the second wing in exactly the same time as the wave 1206 impacts on the first wing, or immediately thereafter. The elevated wing 1201 will pull the wing 102 upwards, by pivot supporting means 1209. The effect of impacting wave 1206 on the position of the first and the second wings, relative to one another, is described in connection with Figs. 12B and 12C.

Fig. 12B schematically illustrates an exemplary intermediate position of the second (wind) wing relative to the first (wave) wing while wave 1206 starts to impact on wing 102. As noted above, the angle λ between the first and the second wings is permitted to change. When the wings are at a rest position, the angle λ is substantially zero. However, as the impacting wave progresses (pushes wing 102), angle λ is growing, until reaching an angle λ_opt that corresponds to the optimal angular displacement of wing

102, as shown in Fig. 12C.

Referring again to Fig. 12B, when wave 1206 starts to impact on wing, a portion thereof (1211) displaces hydrofoil section 1205/H from its vertical equilibrium position 1212, whereby to bring the airfoil section 1205/A to a position where it substantially aligned with the upper surface of wing 102. As a result of this, the gap between the two wings (102 and 1201) is fully exposed to the wind, which acts to elevate wing 1201, and, thereby, to increase the elevation force acting on wing 102, as described hereinabove. The trailing edge of wing 1201 (the edge facing the shore side) is shown separated from the wing trailing edge supporting means 1202.

Fig. 12C schematically illustrates the wings in the optimal position. As wing 102 is driven to its optimal position, by the wave and by the second wing that is elevated by wind, flap weight 1207, thanks to gravity force, pulls downwards hydrofoil section 1205/H, whereby to cause airfoil 1205/A to conceal, again, wing 1201 from the wind. As a result of wing 1201 being concealed from the wind, wing 1201 goes into a stall and the trailing edge (the edge facing the shore side) of wing 1201 gravitationally falls, or stalls (1210), onto the 'back' of wing 102. When in stalled position, the mass of the stalled wing (1201) is added to the mass of wing 102, to cause wing 102 to return to the normal/rest, horizontal, position more rapidly than would have been possible without using wing 1201. When in a stall state, the trailing edge of wing 1201 is supported by wing trailing edge supporting means 1202. Therefore, utilization of wing 1201 is advantageous in two aspects: (1) it translates the energy of the wind to an elevation force that helps displacing wing 102 from its rest position to its optimal position (or, equivalently, to its optimal angle), and (2) when the energy of an impacting wave starts to dissipate, the mass of wing 1201 helps returning wing 102 to its rest position.

While some embodiments of the invention have been described by way of illustration, it will be apparent that the invention can be carried into practice with many modifications, variations and adaptations, and with the use of numerous equivalents or alternative solutions that are within the scope of persons skilled in the art, without departing from the spirit of the invention or exceeding the scope of the claims.

Claims

1. Energy converter, which comprises: a) a buoy, substantially floats on, or near the surface of, the water and substantially maintained in a fixed horizontal position, to serve, among other things, as a floating reference platform; b) a water impervious, outer sleeve having a cylindrical inner surface and having a first wing at its wave side, said sleeve being pivoted to said buoy; c) a generator, housed within said sleeve in a longitudinal manner, comprising magnetic field generation (MFG) means and a rotor, wherein: cl) said MFG means, or, alternatively, said rotor, being a stationary component that is maintained essentially in a fixed position with respect to said buoy; and c.2) said rotor, or, alternatively, said MFG means, being a rotatable component that has an axis of rotation coinciding with the longitudinal axis of said stationary component, said rotatable component being angularly displaced by said sleeve, relative to said stationary component, as a result of said first wing being angularly displaced by, and accordance with, waves impacting said first wing, the relative displacement generating electrical power.

2. Energy converter according to claim 1, wherein the stationary component is the MFG means of the generator, and the rotatable component is the rotor of the generator.

3. Energy converter according to claim 2, further comprising: a) a rotatble member, housed within the sleeve, normally positioned at the bottom of said sleeve and tends to return to said normal position if displaced from it; b) means for permitting said rotatable member to roll but not to slide over said cylindrical inner surface of said sleeve, the rotation of said rotatable member being transferred to said rotatable component of said generator to generate electrical power; and wherein, the generator is normally positioned at the bottom of the sleeve, aligned with said rotatable member, and tends to return, together with said rotatable member, to said normal position if displaced from it, whereby to maintain the MFG means substantially stationary with respect to the buoy.

4. Energy converter according to claim 3, wherein the means for permitting the motor cylinder to roll but not to slide over the cylindrical inner surface of the outer sleeve comprise: a) an inner gearing formed longitudinally and peripherally in or solid with said cylindrical inner surface of said outer sleeve, preferably extending over an angle greater than the maximum angular displacement of said outer sleeve; and b) an outer gearing formed in or solid with the outer surface of said rotatable member, structured so as to mesh with said inner gearing.

5. Energy converter according to claim 4, wherein the inner, longitudinal gearing formed in or solid with said cylindrical inner surface of the outer sleeve extends over an angle of at least 180 ° .

6. Energy converter according to claim 3, further comprising a first (generator) weight, housed by the sleeve, rigidly affixed to the generator, said first weight is allowed to become displaced with the rotatable member and a guide is provided for the first weight to support it during its displacement.

7. Energy converter according to claim 6, wherein the guide is a sliding rail, or sliding channel, rigidly affixed to, or formed in, the inner surface of the outer sleeve, to permit the first weight to slide freely in alignment with the rotatable member.

8. Energy converter according to claim 1, further comprising a second (sleeve) weight attached to the bottom of the outer sleeve and on the inside thereof, to assure that said sleeve always returns to the normal angular position in which said second weight is at its lowest point.

9. Energy converter according to claim 1, wherein the first wing is hollow.

10. Energy converter according to claim 9, wherein the first wing is triangular or circumscribed in a triangle, the base of which is located at the point at which the wing is joined to the outer sleeve.

11. Energy converter according to claim 10, wherein the first wing comprises a plurality of sealed and light-weight tubes, each of which has a diameter that is smaller as the tube is farther from the cylindrical body of the outer sleeve.

12. Energy converter according to claim 10, wherein the first wing consists of cells, each cell having a wide opening that is directed to a direction substantially perpendicular to the plane of said wing, such that, whenever said wing is in a rest, or horizontal, position, the wide openings of said wing cells face the water side and are fully soaked in the body of water, each cell including also a narrower, elongate, vent opening to connect the interior of the cell to the atmosphere in the opposite side of said wing such that whenever the wing is in horizontal position, the water 'pushes' the air locked in the interior of said cells through the respective vent opening, to fill with water the interior spaces of the wing cells, said cells being arranged such that the closer are the cells to the sleeve, the larger is their interior space, and therefore, the larger is their water-holding capacity.

13. Energy converter according to claim 12, wherein each wing cell includes a one-way valve, which can be either in "CLOSE" state or in "OPEN' state, which opens whenever water pushes air from the interior of the wing cell to the atmosphere through the vent opening, and, thanks to the lower pressure which results from the water locked in the cells, relative to the atmospheric pressure, the one-way valve closes whenever the wing returns to its normal, horizontal, position, whereby to effect a 'suction' phenomenon, according to which the water of the dissipating wave, which previously filled the cells and lifted the wing, now pull the wing in a downwards direction, thus reducing the Degree of Freedom (DOF) between the first wing and the waves impacting on it, whereby to exploit the 'downwards' motion of each individual wave, as well as its 'upwards' motion.

14. Energy converter according to claim 1, wherein the buoy is provided with two, or more, flexible mooring ties that are transversely spaced from one another and connected to respective anchors fixed on the sea bottom.

15. Energy converter according to claim 1, wherein the buoy includes a water impervious, empty portion, such as to impart to it the buoyancy required for it to float.

16. Energy converter according to claim 1, wherein the buoy has on the wave side an upper surface so shaped as to direct the waves towards the first wing, and on the shore side has a lower surface shaped to repel water flowing back from the shore.

17. Energy converter according to claim 16, wherein the end of the lower surface of the buoy, which faces the shore side, is longitudinally curved to form an opening that is directed generally downwards and towards the wave side, said opening is divided, substantially in longitudinal manner, into a plurality of buoy cells that are positioned mostly underneath the surface of the water, and therefore, water fully occupy the interior spaces thereof, to exert on the buoy a force, in the form of suction force, that counteracts the force exerted by impacting waves on the upper surface of the buoy, whereby to stabilize the buoy in substantially horizontal position, each buoy cell including a wide opening, a narrow elongate passage and a one-way valve.

18. Energy converter according to claim 12 or 17, in which the cells are structured as a honeycomb.

19. Energy converter according to claim 1, wherein the stationary component is the rotatable member, and the rotatable component is the MFG means.

20. Energy converter according to claim 19, further comprising: a) for each of the two opposing sides of the sleeve, a hollowed pivot, through which a corresponding rotor's shaft passes in a frictionless manner; b) between each pivot and the rotor's shaft passing through it, sealing means, for preventing water from entering the sleeve; c) fastening means, for rigidly fastening the rotor's shaft to the buoy, for inhibiting angular displacement of the rotor with respect to said buoy; and d) anchoring means, for anchoring the generator, and therefore the MFG means, to the inner surface of said sleeve, whereby to allow relative angular displacement between said rotor and said MFG means of said generator, as a function of the angular displacement of the first wing, and therefore of the sleeve, to generate electrical energy.

21. Energy converter according to claim 20, in which each one of the pivots is pivotly supported by the buoy, for allowing rotational displacement of the sleeve.

22. Energy converter according to claim 1, further comprising a 'dynamic mass arrangement' to maximize the efficiency of said converter by self- adaptation to changes that occur in the waves' parameters, particularly frequency and amplitude, comprising: a) a first container, adapted to be filled and emptied with/from liquid, the mass of said first container and the mass of the liquid contained therein (if not empty) are added to the mass of the sleeve's weight to exert additional moment to return the sleeve, and therefore the first wing, to its rest, or normal, position; b) a second container, adapted to be filled and emptied with/from liquid, the mass of the second container and the mass of the liquid contained therein (if not empty) are subtracted from the mass of the sleeve's weight, wherein said containers are housed within said outer sleeve and being connected to one another by two conduits, 'fill' and 'return' conduits, so shaped and located that if said first container is full and said second container is empty, while there is a series of low waves, each wave exceeding a given low threshold, said 'fill' conduit will transfer liquid from said first container to said second container, whereby to expand the frequency response of said converter by decreasing the moment of inertia of said outer sleeve, and/or by decreasing the, or compensating for, the mass added to the mass of said sleeve's weight, whereas if said second container is full and the first container is empty, while the waves are high, said 'return' conduit will return the liquid from said second container to said first container, whereby to effect the opposite effect.

23. Energy converter according to claim 22, in which the first container substantially lays on a longitudinal line passing substantially through, or near, the sleeve's weight, and the second container may, or may not, lay on a plane passing through the axis of rotation of the sleeve and said sleeve's weight.

24. Energy converter according to claim 22, in which the second container lays on the axis of rotation of the sleeve.

25. Energy converter according to claim 22, in which the second container lays on the inner surface of the sleeve, opposite to the first container.

26. Energy converter according to claim 1, in which the outer sleeve further comprises a mechanical stopper for assuring that the first wing will not turn the converter unit upside down when being impacted by high waves, by engaging with the generator, which is coupled to the first (generator's) weight and to the mass of the rotatable member, to displace it from its normal position, whereby to exert, via the stopper, a 'return' moment on said outer sleeve to return said sleeve to its normal position, said return moment is a function of the difference between the actual angular displacement of the sleeve (a) to a value of an angle o _enga that

conforms to the conditions 90° < a_engage « 180° and ≥ ct_engage .

27. Energy converter according to claim 22, in which said converter further includes, internally or externally to the outer sleeve, basic, simple, circuitry for initial stabilization of the electricity produced by said converter.

28. An energy system, comprising a plurality of energy converter units, serially 'chained', or linked, to one another to yield an electrical output that is substantially the sum of the electrical output of the individual energy converter units.

29. Energy converter, substantially as described and illustrated.