Apparatus for Power Generation Using Wave and Wind Energy

Field of the Invention.

The present invention relates to apparatus for power generation. In particular, the present invention relates to apparatus for power generation that harnesses wind and wave power.

Background Art.

Traditionally, the generation of power, such as electrical power, has been achieved through the use of fossil fuels such as coal, natural gas and oil. However, in recent times, due to the decreasing reserves of fossil fuels and the environmental impact of their use in power generation, cleaner alternatives for the generation of power have become more popular.

Despite the fact that they are considerably more environmentally-friendly, these alternative power generation techniques (solar, wind, wave, geothermal etc) have struggled to gain widespread acceptance due to their inefficiencies in generating power, their high cost to establish in comparison to existing fossil fuel technology and their lack of aesthetic appeal (such as wind farms).

Therefore, there would be an advantage if it were possible to provide apparatus for power generation that efficiently generated power without having a detrimental impact on the environment.

It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.

Throughout this specification, the term "comprising" and its grammatical equivalents shall be taken to have an inclusive meaning unless the context of use indicates otherwise.

Object of the Invention.

It is an object of the present invention to provide apparatus for power generation which may overcome at least some of the abovementioned disadvantages, or provide a useful or commercial choice.

In one aspect of the invention there is provided a power generation apparatus comprising a housing adapted for at least partial immersion in a body of water, the housing comprising a first chamber and a second chamber, the first chamber adapted to allow the flow of water moving in a first direction therethrough and the second chamber adapted to allow the flow of water moving in a second direction therethrough, and wherein each of said first and second chambers include power generation means.

The power generation apparatus may be used in any suitable body of water, such as a lake, river, ocean and so on. However, the power generation apparatus will be most effective when used in a body of water in which there is a wave motion. Preferably, the wave motion in the water will produce movement of the water in more than one direction. In a most preferred embodiment of the invention, the wave motion will produce movement of the water in two directions, the two directions being substantially opposite to one another. Therefore, in order to achieve this, it is preferred that the power generation apparatus is used in a body of water near an obstacle that will cause the movement of water in two substantially opposite directions, such as a river bank, shoreline, beach, retaining wall and so on.

The housing may be of any suitable type. However, it is preferred that the housing is suitable for at least partial immersion in a body of water, for instance, by being constructed from a corrosion resistant material. This is of particular importance if the power generation apparatus is to be used in saltwater. Any suitable corrosion resistant material may be used for the construction of the housing, such as corrosion resistant metal, plastic, fiberglass and so on.

The power generation apparatus may be adapted to float partially submerged in the body of water, or may rest on the bottom of the lake, river, ocean and the like.

Alternatively, the power generation apparatus may be mounted on a mounting, such as one or more poles, frame and the like. The mounting may have a fixed or adjustable height. The height may be adjustable and optimized such that any wave breaking will preferably break through the first chamber and the water withdrawing back to the body of water will preferably occur through the second chamber.

In an alternative embodiment of the invention, the power generation apparatus may be suspended from above in the body of water, such as from overhead wires, an over head frame, a crane, bracket or boom and so on. In another embodiment of the invention, the power generation apparatus is adapted to be retained relative to an existing structure, such as, but not limited to, a wharf, jetty, landing, oil rig, sea platform and so on.

If the power generation apparatus is adapted to float in a body of water, it may further be provided with means for maintaining the position and orientation of the power generation apparatus relative to the shore, beach, retaining wall or the like at all times. Any suitable means may be used to maintain the position and orientation of the power generation apparatus, hi addition, the power generation apparatus may be provided with wave piercing means to ensure that the power generation apparatus remains upright in the body of water even when being pounded by large waves. The wave piercing means may be of any suitable type and configuration, although in a preferred embodiment of the invention, the wave piercing means comprises one or more tapered points located on the exterior surface of the power generation apparatus.

The first and second chambers may be arranged within the housing in any configuration. However, it is preferred that the chambers are arranged such that only water flowing in a single direction will enter each chamber. Therefore, it is preferred that the first chamber is located substantially above the second chamber within the housing, hi this way, waves breaking against the beach, shore, retaining wall and the like will enter a first upper chamber, while water flowing away from the beach, shore, retaining wall and the like will enter a second lower chamber.

The arrangement of the chambers may effectively create a chamber within a chamber,

thereby creating a downward vortex effect. This creates a increase in the fluid's kinetic energy or centrifugal force which may be transferred to a turbine.

In some embodiments of the invention, each of said first and second chambers may be provided with one or more inlets and one or more outlets through which water enters and exits the chamber. Preferably, each chamber is provided with a flow pathway between the inlet and the outlet through which water may flow. The flow pathway may be defined by upper and lower walls and two or more side walls, hi some embodiments of the invention, one or more of the walls defining the flow pathway may be shaped so as to channel the flow of water through the flow pathway and/or to increase the velocity of water flowing through the flow pathway.

In some embodiments of the invention, the flow pathway is shaped so as to improve enhance the flow of water to the power generation means. The flow pathway may be provided with a twisted, helical, curved, tapered or any other suitable shape for increasing the velocity of the water in the flow pathway.

In addition, in some embodiments of the invention, as the water exits the flow pathway through the one or more outlets, it is preferred that the flow of water enhances the operation of the power generation means, such as, but not limited to, by producing a Venturi effect as the water moves through the flow pathway.

One or more of the inlets or outlets of each of the chambers may be provided with protective means. The protective means may be of any suitable form, such as, but not limited to, a screen, grate, mesh or the like. The protective means may be provided to cover at least a portion of the said inlets or outlets in order to prevent unwanted objects such as people, detritus or marine life from accidentally entering the power generation apparatus and being injured or trapped within the apparatus. In addition, the protective means may serve to prevent fouling of the workings of the power generation apparatus by seaweed and the like. In addition, the power generation apparatus may be provided with warning means, such as a light, beacon, siren or the like to alert swimmers and/or vessels to the presence of the power generation means.

As described previously, each of the first and second chambers comprises power generation means. Preferably, the power generation means are located in the flow pathway intermediate the inlet and the outlet of each of said chambers. The power generation means may be of any suitable form. Preferably, the power generation means are adapted to convert the energy imparted by the flow of water through the chamber to some other form of energy, such as electrical energy.

hi some embodiments of the invention, the power generation means comprises one or more rotational means, such as, but not limited to, a turbine. The one or more rotational means may be adapted to rotate in one direction only, such that any water entering a chamber in the opposite direction to the intended direction will not cause rotation of the rotational means in the wrong direction. The one or more rotational means may be provided on their own axles in each chamber, or may be provided on common axles extending through both the first and second chambers when the first and second chambers are located one above the other. The one or more rotational means may be adapted to rotate simultaneously, or may be individually rotatable even if provided on a common axle. If the rotational means is a turbine, the turbine may be of any suitable shape and size.

The one or more rotational means may be provided with means for enhancing the rotation of the one or more rotational means. In one embodiment of the invention, the means for enhancing the rotation comprises a plurality of vanes extending outwardly from the outer surface of the rotational means. The plurality of vanes may be of any suitable shape or size and located in any suitable position on the rotational means, and at any suitable angle to the water entering the chamber.

In some embodiments of the invention, rotation of the rotational means transfers energy to the power generation portion of the power generation apparatus. The power generation portion is preferably located in an upper portion of the power generation apparatus. Preferably, the power generation portion is located above the surface of the body of water in order to prevent damage by water and also to improve accessibility when maintenance or the like is required.

The power generation portion may comprise power generation means housed within the power generation portion. The power generation means may be of any suitable type. In some embodiments of the invention, the power generation means may comprise a flywheel, the flywheel being connected to, for instance, a generator rotor to generate electricity. In an alternative embodiment of the invention, the flywheel may be adapted to drive a compressor pulley, the compressor pulley being itself adapted to drive an air compressor. The air compressor may preferably transfer compressed air to an accumulator tank, the high pressure air within the accumulator tank being used to drive a turbo-generator and generate electricity.

The air drawn into the air compressor may be filtered and dried. Air drying may be achieved using any suitable technique, such as, but not limited to, using energy collected by one or more solar energy collection devices to dry the air.

In embodiments of the invention in which a solar energy collection device is provided in association with the power generation apparatus, the solar energy collection device may also be used to supply additional electricity to the power generation apparatus during times of peak electricity demand or during periods when there are few waves. The solar energy collection device is preferably located at an upper portion of the apparatus.

The power generation apparatus may be adapted for connection to other pieces of equipment, such as the discharge of a desalination plant, in order to ensure a steady supply of water through the chambers.

Electricity generated by the power generation apparatus may be stored in batteries or the like, or the power generation apparatus may be connected directly to a power grid.

Calculations for the design and operation of a power generation apparatus according to an embodiment of the invention are set out below in Tables 1 and 2.

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of fluid through the power generation apparatus, the power generation apparatus further comprising power generation means in communication with the at least one rotational means.

The housing of the power generation apparatus may be of any suitable form. In some embodiments of the invention, the housing comprises an elongate tubular member. Preferably, the housing is positioned substantially vertically, such that the lower end of the housing may be connected to the ground, footings or the like.

Preferably the housing is substantially hollow. In a preferred embodiment of the invention, the upper end of the housing is at least partially open, hi some embodiments of the invention, the upper end of the housing may serve as an outlet for the fluid flowing through the power generation apparatus. The open upper end of the housing may be partially covered by covering means, in the form of a dome, cone, deflector and the like. The covering means may be used to prevent rain, snow and the like from entering the housing. The covering means may also serve as storage or mounting portion for additional equipment, such as solar energy collection devices and the like. The solar energy collection device may be used to power, for instance, a light provided at the uppermost point of the power generation apparatus, such as to alert people to its presence.

The housing may be constructed as a single piece or may comprise a number of individual modules connected together. In this embodiment, the modules are preferably oriented in a substantially vertical configuration, mounted one atop another. This design assists in creating an upward vortex effect, which increases the kinetic energy (or centrifugal force) of the fluid flow through the housing which may be transferred to a turbine. The individual modules may be stacked from ground level. This may assist in eliminating the need for using a crane when the apparatus is to be installed on top of a building or in a confined space.

The one or more inlets may be provided at any suitable location on the power generation apparatus. Preferably, however, the one or more inlets are provided in the surface of the housing and extend therethrough, hi some embodiments of the

invention, the one or more inlets are provided at intervals along at least a section of the entire length of the housing. However, in other embodiments of the invention, the one or more inlets are located at substantially the same height on the housing. Preferably, in this embodiment of the invention, the one or more inlets are located in a lower portion of the housing.

In a most preferred embodiment of the invention, the fluid may enter the housing through one or more inlets located in a lower portion of the housing and exit the housing through one or more outlets located in an upper portion of the housing. Still more preferably, the fluid may exit the housing through the at least partially open upper end of the housing.

The one or more inlets and/or the one or more outlets may be provided with protective means. The protective means may be any suitable means, such as a grille, screen, mesh and the like that at least partially cover the one or more inlets and/or one or more outlets. The use of the protective means may prevent unwanted objects such as birds, animals or debris from entering the power generation apparatus.

In a preferred embodiment of the invention, the fluid is air, particularly air in the form of wind.

In some embodiments of the invention, the rotational means comprises one or more devices, such as, but not limited to, turbines. The one or more rotational means may be adapted to rotate in one direction only, such that any fluid entering the housing will cause rotation of the rotational means only in the one direction. The one or more rotational means may be provided on their own axles, or may be provided on a common axle extending through the length of the housing. The one or more rotational means may be adapted to rotate simultaneously, or may be individually rotatable even if provided on a common axle. A significant advantage may be gained from allowing the one or more rotational means to rotate independent of one another in that as the strength of the wind entering the power generation apparatus increases, additional rotational means may begin to rotate, thereby slowing the rotation. This significantly reduces the likelihood of the power generation apparatus being damaged or burning

out due to high speed rotation of the rotational means.

In one embodiment of the present invention, the power generation apparatus may be provided with two or more sets of rotational means. The first set of rotational means may be provided with a hollow bore located longitudinally therethrough, while the second set of rotational means may be located within the hollow bore. The first set of rotational means may therefore be located in an annular portion of the apparatus between an outer wall of the apparatus and a wall of the hollow bore. The central axis through the first set of rotational means may be coaxial with the central axis through the second set of rotational means, or it may be offset therefrom. Alternatively, the first and second set of rotational means may share a common axle which may be central to only one, or neither of the rotational means. By providing the power generation apparatus with first and second sets of rotational means, the power generated by the power generation apparatus may be increased without any corresponding increase in the size of the power generation apparatus, hi some embodiments of the invention, the first set of rotational means may not, in fact, be rotational, and may instead be stationary. These stationary means may be adapted to direct fluid onto the second set of rotational means.

The one or more rotational means may be provided with means for enhancing the rotation of the one or more rotational means, hi one embodiment of the invention, the means for enhancing the rotation comprises a plurality of vanes extending outwardly from the outer surface of the rotational means. The plurality of vanes may be of any suitable shape or size and located in any suitable position on the rotational means, and at any suitable angle to the fluid entering the housing.

hi some embodiments of the invention, rotation of the rotational means transfers energy to a power generation portion of the power generation apparatus. The power generation portion is preferably located in an lower portion of the power generation apparatus.

The power generation portion may comprise power generation means housed within the power generation portion. The power generation means may be of any suitable

type. In some embodiments of the invention, the power generation means may comprise a flywheel, the flywheel being connected to, for instance, a generator rotor to generate electricity. In an alternative embodiment of the invention, the flywheel may be adapted to drive a compressor pulley, the compressor pulley being itself adapted to drive an air compressor. The air compressor preferably transfers compressed air to an accumulator tank, the high pressure air within the accumulator tank being used to drive a turbo-generator and generate electricity.

The air drawn into the air compressor may be filtered and dried. Air drying may be achieved using any suitable technique, such as, but not limited to, using energy collected by one or more solar energy collection devices to dry the air.

hi an embodiment of the invention, a solar energy collection device may be provided and in the embodiments in which a solar energy collection device is present, the solar energy collection device may also be used to supply additional electricity to the power generation apparatus during times of peak electricity demand or during periods when there is little wind.

The power generation apparatus may be constructed from any suitable material, such as plastic, metal, fiberglass and the like. The individual components of the power generation apparatus may be constructed from the same or different materials.

In another aspect of the invention there is provided a clutch assembly comprising a pair of clutch plates associated with a shaft, one or more biasing means and one or more expansion means adapted to facilitate movement of the pair of clutch plates relative to one another upon rotation of the shaft.

In a preferred embodiment of the invention, the one or more expansion means are located between the pair of clutch plates. The expansion means may be of any suitable form, provided that the expansion means is adapted to move the pair of clutch plates relative to one another under the centrifugal force produced by the rotation of the shaft and/or the plates.

In a preferred embodiment of the invention, the expansion means comprises a central hub and at least a pair of projections interconnecting the central hub and the clutch plates. Preferably, the projections and the central hub are arranged in a substantially sideways V-shaped configuration.

The projections may be adapted to pivot relative to the central hub, such that when a centrifugal force is applied to the expansion means, the projections pivot relative to the central hub, thus contracting or expanding the clutch plates, depending on the orientation of the expansion means. If the expansion means are located with the central hub positioned closer to the shaft than the point at which the projections connect to the clutch plates, rotation of the shaft will cause the expansion means to expand the clutch plates away from one another. Alternatively, if the expansion means are positioned with the central hub positioned further from the shaft than the point at which the projections connect to the clutch plates, rotation of the shaft will cause the expansion means to retract the clutch plates towards one another.

The central hub may comprise a single component, or may be constructed from one or more pieces connected together, hi one embodiment of the invention, each projection is formed integrally with a portion of the central hub, such that the two pieces may be connected together in a pivoting engagement. The portions of the central hub can rotate relative to one another changing the effective separation of the pair of projections. The central hub will normally be weighted.

Preferably, the expansion means is provided with stop means to limit the pivoting of the projections. The stop means may be of any suitable form, although it is preferred that the stop means is provided at a point on the central hub so as the clutch plates are prevented from coming into contact with one another when the expansion means is in the fully retracted position.

In some embodiments of the invention, the clutch assembly is provided with a plurality of expansion means, hi a most preferred embodiment of the invention, the clutch assembly comprises six expansion means, each of the expansion means spaced at approximately 60° intervals around a circular clutch plate.

The biasing means may be of any suitable form. However, in some embodiments of the invention, the biasing means comprises one or more springs. Preferably, the one or more springs may be capable of adjustment in order to vary the centrifugal force required to overcome the biasing means in different applications of the clutch assembly.

In an alternative embodiment of the invention, the expansion means may comprise a pair of wedges, the first of said pair of wedges associated with a first clutch plate, and the second of said pair of wedges associated with a second clutch plate. In a preferred embodiment of the invention, the wedges may be adapted for movement relative to one another in a horizontal plane, a vertical plane, or a combination of the two. The wedges may both be adapted for movement relative to one another, or only one wedge may be adapted for movement while the other is held stationary.

The wedges may be of any suitable shape. However, in a preferred embodiment of the invention, the wedges are triangular in shape. Suitably, the wedges are positioned sop that an angled face of each wedge is facing the other wedge, In a most preferred embodiment of the invention, the wedges are in the form of right-angled triangles, wherein the hypotenuse of each wedge is positioned facing the corresponding side of the other of the pair of wedges.

hi a preferred embodiment, one of the wedges is held stationary, while the other wedge is located on sliding means, the sliding means adapted for sliding engagement with a clutch plate, hi this embodiment of the invention, centrifugal forces produced by the rotation of a shaft result in the sliding means moving in a horizontal direction relative to the surface of the clutch plate. Movement of the sliding means causes the angled faces of the wedges to slide over one another, forcing the clutch plates apart or together, depending on the orientation of the wedges.

In another aspect of the invention there is provided a power take off assembly comprising: a. at least one shaft member;

b. at least a pair of flywheels including a first flywheel and a second flywheel larger than the first flywheel, each flywheel associated with the at least one shaft member; c. at least a pair of clutch assemblies as hereinbefore described associated with the second flywheel; d. at least one power input device; and e. a power take off means associated with the first flywheel; wherein rotation of the at least one shaft member by the power input device to a predetermined rotational velocity whereupon at least one of the pair of clutch assemblies engages to connect the first flywheel and the power take off means allowing inertial and kinetic energy to transfer between the first flywheel and the power take off means to accelerate the power take off means.

Obviously, the engagement of the power take off means will cause the flywheels to slow. The power input device will preferably continue to add power to the shaft to decrease the amount of slowing, but in time, the power take off means will attain the rotational velocity of the flywheels and be accelerated to the predetermined rotational velocity by the power input device. Preferably, once the initial inertia of the power take off means is overcome and it begins to rotate, the power input device will have sufficient power to accelerate both the shaft and the power take off means back to the predetermined speed. It is therefore important to minimise the energy losses in the device to ensure that as much of the input power or energy is directed towards accelerating the assembly.

The assembly will typically be enclosed by a housing both to protect the power take off system from damage and energy depleting effects from external forces and also to prevent damage to surrounding objects should the flywheels rupture.

The device of the present invention will preferably include at least one shaft member. There will typically be a single shaft member although it is possible to use more than one provided that all of the shafts are coaxially mounted.

The shaft may be appropriately mounted for rotation and in this form the shaft will be supported and/or oriented by one or more bearings. Alternatively, the shaft may be fixed and the flywheel may be mounted for rotation about the fixed shaft.

The shaft may be oriented horizontally or vertically, but a vertical orientation is preferred. A horizontally oriented shaft member will require multiple shaft support bearings which add to the friction in the system and effectively decreases the amount of energy which is transmitted to the power take off means. The shaft will typically be of circular cross-section but may not be of constant dimension.

The shaft maybe manufactured of materials similar to the flywheels as it will typically be subjected to the same forces albeit not to the same extent. Therefore the material used may be metal for lower speed applications and composite materials for higher speed applications.

The flywheels will preferably have a stepped cross-section with a thinner outer annular portion surrounding or extending from a thicker central annular portion. The flywheels may be of unitary construction or they may be split flywheels, particularly the larger flywheels. The split-system flywheel is to allow the thrust/load of the flywheel to be well distributed on the shaft both radially and longitudinally to reduce the friction loss.

In some embodiments of the invention, there will suitably be a number of flywheels in the power take off assembly. It is realised that the more flywheels in the power take off assembly and the closer in dimension to one another, the smaller the losses in speed will be when the clutch is disengaged but the greater the capital cost and size of the device.

The assembly of the present invention will typically find application in power smoothing applications for power generation apparatus, such as power generation apparatus that make use of wind and wave power to generate electricity (the power input device of the present invention). Such power generation apparatus may include those previously described in the present application. The power take off assembly

may be of particular use in these power generation apparatus when the rotation of a shaft becomes too rapid, such as during storms, cyclones, tidal waves and the like, and there is a danger that such rapid rotation of the shaft will lead to damage to, or the burning out of, generators or similar devices.

In embodiments of the invention in which the power take off assembly is connected to a power generation apparatus as described above, the shaft may be a common shaft that interconnects the rotational means of the power generation apparatus with the power generation portion (for instance, a generator). Preferably, the power take off assembly is disposed on the shaft at a point intermediate the rotational means and the power generation portion of a power generation apparatus.

Where the power generation apparatus is provided in a modular configuration, the rotational means of each module will typically be connectable using a clutch means. The clutch will normally engage an adjacent module when the rotational speed of the first module approaches or passes a predetermined speed.

The clutch assembly will preferably include a number of parallel plates at least one of which may be moveable in relation to each other towards and away from the flywheels but not radially. The plates will usually include at least a clutch plate and a guide plate. There will also typically be at least one clutch pad associated with the clutch plate.

There is typically a mounting flange located at a first end of the clutch assembly to mount to (or relative to) the flywheel against which the clutch assembly is positioned.

The flange will normally attach to the surface of the flywheel using appropriate fasteners or be cast or formed integrally with the flywheel.

The flange will usually have a hollow tubular spacing portion extending from the flange with a central bore therethrough for mounting on the shaft of the power take off assembly.

The guide plate is normally located at a lower end of the spacing portion. The guide plate is typically the main plate of the clutch assembly and most, if not all, of the components of the clutch assembly are preferably mounted to the guide plate.

The guide plate will preferably be a substantially circular, solid plate member with a central opening again for mounting the shaft of the flywheel system. Located between the central opening and the outer edge of the guide plate is preferably at least one and typically more than one, slot opening. The slot openings will usually radiate from the central opening and be equally spaced about the guide plate. The slot openings may have rebated edges so that the gyro weights can be at least partially received within the slot openings.

The slot openings are guide openings for the travel of the gyro weights upon which the operation of the clutch of the present invention is based. The gyro weights are mounted relative to the slot openings to be maintained in the slot openings and to slide inwardly and outwardly in the slot openings. A portion of the gyro weight will therefore typically abut the upper surface (the surface closest to the smaller flywheel) of the guide plate. A portion of the gyro weight will also typically abut the lower surface (the surface closest to the larger flywheel) of the guide plate. There may be friction minimising means located between the abutting surfaces.

The upper and lower portions of the gyro weight will normally be attached to each other and the separation distance between them may be adjustable. Typically screw fasteners are used and loosening or tightening the screw fasteners will preferably adjust the separation distance.

Mounted relative to the lower extremity of each gyro weight will normally be a bearing or similar. The bearing may be an annular, or spherical bearing. Typically, the lower portion of the gyro weight will be provided with a bearing engagement portion which will differ in configuration depending upon the type of bearing. For example, an annular bearing will require that the bearing engagement portion be a pair of spaced apart legs with a bearing axle. The annular bearing is received between the legs and the axle extends through the bearing and engages with the legs to fix the

bearing in place. Typically the bearing will be positioned such that the bearing rotates in a direction parallel to the direction of the slot opening in which the gyro weight is located. A spherical bearing will likely require a hemispherical "cup" portion to hold the spherical bearing but still allow rotation about any axis.

The location and length of the slot openings in the guide plate will preferably be such that travel of the gyro weights will be prevented beyond a particular point regardless of how much faster the guide plate rotates. The weight of the gyro weights will be optimised to determine at what rotational velocity the gyro weights are forced outwardly.

The clutch plate is normally an annular plate that is mounted to rotate about the shaft of the flywheel system. Typically a central opening is provided. The clutch plate will preferably have an upper surface (the surface closest to the smaller flywheel) and a lower surface (the surface closest to the larger flywheel). As stated previously, the clutch plate will normally be provided with at least one and typically more than one clutch pad for contacting the flywheel when the clutch assembly is engaged and normally the clutch pad(s) will be provided on or adjacent the lower surface of the clutch plate.

The clutch plate is typically mounted on the shaft of the power take off assembly as well. Preferably, the clutch plate is mounted for movement towards and away from the flywheel and therefore is usually provided with a neck portion located about the shaft. The neck portion may also engage with the spacing portion of the clutch assembly and normally will be telescopically engaged allowing guided movement. There may be a locking arrangement provided between the neck portion and the spacing portion to prevent the clutch plate from moving to disengage with the flywheel once engaged due to the centrifugal force. Alternatively, there may be a mechanism to periodically engage and disengage the clutch plate from the flywheel to minimise the loss of too much speed of the drive means during the acceleration of the flywheel. The mechanism may disengage the clutch plate once the speed of the drive means drops below a predetermined speed to allow the drive means to accelerate before re-engagement.

Angle means will be provided on or adjacent the upper surface of the clutch plate. Preferably, the angle means will be provided in an annular band area towards the outer edge of the clutch plate. The angle means may be provided as a single annular angle means or as a plurality of spaced apart discrete angle means.

The angle means may be provided with locking means to prevent disengagement of the clutch plate from the flywheel once the engagement has been made. Alternatively, there may be a mechanism to periodically engage and disengage the clutch plate from the flywheel to minimise the loss of too much speed of the drive means during the acceleration of the flywheel. The mechanism may disengage the clutch plate once the speed of the drive means drops below a predetermined speed to allow the drive means to accelerate before re-engagement.

The clutch plate will normally be biased towards the guide plate by appropriate resilient means. Normally a plurality of rod or bolt members can be used extending through the guide plate and engaging (normally extending through) the clutch plate and associated with resilient means to bias the plates together. The resilience of the resilient means can determine or assist with determination of the predetermined speed at which the clutch will engage as well. Normally, the resilient means may be a spring or similar mounted about the rod and located between the guide plate and a head of the rod or bolt members.

The power take off assembly of the invention will preferably engage and disengage automatically at a specified rotational speed through activation of centrifugal forces on the expansion means. The expansion means may be of any suitable form. In some embodiments of the invention, the expansion means comprises one or more biasing means located between the plates of the clutch assembly. The biasing means may be of any suitable form, such as springs or wedges and the like. In a preferred embodiment of the invention, rotation of the shaft at a predetermined rotational speed will create centrifugal forces sufficient to overcome the biasing means and cause the expansion means to expand, thereby moving the clutch plates apart. The tensioning of the biasing means may be adjustable so as to alter the centrifugal forces required to

overcome the biasing means depending on the application in which the assembly is used.

As this occurs, the first flywheel will approach the power take off means until a point at which the power take off means and the first flywheel engage and rotational movement is transferred from the first flywheel to the power take off means.

As rotation of the shaft slow, the centrifugal forces will decrease, leading to a contraction of the expansion means. If the contraction is sufficiently large it will lead to the disengagement of the first flywheel from the power take off means.

The power take off means may be of any suitable form, such as, but not limited to, an additional flywheel. The engagement between the first flywheel and the power take off means may be enhanced by the presence of gears and the like interposed between the first flywheel and the power take off means.

The power take off means may be connected to any suitable device. For instance, the power take off means may be connected to a power generation device to generate electricity.

hi yet another aspect of the invention there is provided a device for generating electricity comprising: a. at least one rotatable shaft member; b. a sleeve mounted on said shaft member and rotatable therewith; c. one or more vanes affixed to the sleeve; and d. electricity generation means in communication with said at least one rotatable shaft member; wherein the action of a force on the vanes causing the rotation of the rotatable shaft member, rotation of the rotatable shaft member in turn driving the electricity generation means.

Forces acting on the vanes may include the action of wind or waves.

Brief Description of the Drawings.

An embodiment of the invention will be described with reference to the following drawings in which:

Figure 1 illustrates a power generation apparatus according to one embodiment of the present invention;

Figure 2 illustrates a plan view of a power generation apparatus according to one embodiment of the present invention; Figure 3 illustrates a cross-sectional view of a power generation apparatus according to one embodiment of the present invention; Figure 4 illustrates a power generation apparatus according to another embodiment of the present invention; Figure 5 illustrates a cross-sectional view of a power generation apparatus according to another embodiment of the present invention;

Figure 6 illustrates a plan view of a power generation apparatus according to another embodiment of the present invention;

Figures 7-8 illustrate a power take off assembly according to an embodiment of the present invention; Figures 9-11 illustrate clutch assemblies according to embodiments of the present invention.

Detailed Description of the Drawings.

It will be appreciated that the drawings have been provided for the purposes of illustrating preferred embodiments of the present invention and that the invention should not be considered to be limited solely to the features as shown in the drawings.

hi Figure 1 there is shown a power generation apparatus 10 according to an embodiment of the present invention. The power generation apparatus 10 is partially immersed in a body of water 11 close to a beach 12. Waves 13 adjacent the surface of the body of water 11 pass through a first upper chamber 14 of the power generation apparatus 10 on their way to the beach 12. Water 15 flowing away from the beach 12 and back out to sea passes through a second lower chamber 15 of the power generation apparatus 10.

The power generation apparatus 10 is provided with a power generation portion 16 located in an upper portion of the power generation apparatus 10. The power generation portion 16 is located above the surface of the body of water 11 both to protect the power generation means (obscured) from water damage and also to ensure that the power generation means (obscured) are readily accessible when maintenance is required.

The power generation apparatus 10 further comprises a light or beacon 17 adapted to mark the position of the power generation apparatus 10, particularly at night, to prevent swimmers, surfers and vessels from colliding with the power generation apparatus 10.

Figure 2 of the drawings illustrates a plan view of the internal workings of the power generation apparatus 10 according to an embodiment of the present invention. Incoming waves 13 enter a first upper chamber 14 and are funneled through a flow pathway 18 by the walls 19 of the chamber 14. The water flowing through the chamber 14 contacts a turbine 20 causing the turbine 20 to rotate. Water exits the apparatus 10 through an outlet 21. Similarly, water 22 returning from the beach or the like enters a second lower chamber 15 and is funneled through a flow pathway 23 defined by the walls 24 of the chamber 15. The water flowing through the chamber 15 contacts a turbine 20 causing the turbine 20 to rotate. Water exits the apparatus 10 through an outlet 25. The turbine 20 in each of the chambers 14,15 has a common shaft 26 upon which the turbine 20 is mounted.

Rotation of the turbine 20 transfers rotational energy to the power generation portion (not shown) of the apparatus, where power, in the form of electricity, is generated.

The apparatus 10 is provided with wave piercing tips 27 to ensure that the apparatus 10 maintains its orientation even when being pounded by large waves.

The apparatus 10 further comprises a pair of supports 28 for holding the apparatus 10 in place during use. Water deflectors 29 may also be used to assist in maintaining the position of the apparatus 10.

In Figure 3 of the drawings a cross-sectional view of the upper chamber 14 of the power generation apparatus 10 of the present invention is shown. The turbine 20 comprises a shaft 30 having a sleeve 31 for supporting a bearing 32. The shaft 30 is provided with an outer skin or tube 33 to which the turbine blades or vanes 34 may be attached.

The shaft 30 is provided with a one-directional wheel 35 and one-directional ratchet leys 36 to allow rotation of the turbine 20 in one direction only. Flywheels 37 are also provided at the upper and lower ends of the turbine 20.

The turbine 20 may be provided with a cover 38 to assist in water-proofing the power generation portion (not shown). The base of the shaft 30 may be provided with a support 39 adjacent the floor 40 of the first chamber 14 that also serves as the roof 40 of the second chamber 15.

Turning now to Figure 4 there is shown a power generation apparatus 41 according to another embodiment of the present invention. The power generation apparatus comprises an elongate tubular housing 42 erected so as to be substantially vertical and fixed in place using bolts 43. A guy wire 44 may also be used to hold the housing 42 in place, the guy wire 44 being attached to a mooring and tensioning point 45 at the base of the housing 42.

The housing 42 comprises a plurality of modules 46 connected together to form the apparatus 41. The open upper end 47 of the housing 41 serves as an outlet for wind passing through the apparatus 41. Placed above the outlet 47 is a draft cone 48 to deflect and disperse the wind exiting the apparatus 41.

The lower portion of the apparatus 41 is the power generation portion 49 comprising the power generation means 50. The power generation portion 49 is provided with a pair of service doors 51 to allow access to the power generation portion 49 for maintenance purposes.

Figure 5 shows a cross-sectional view of one of the modules 46 illustrated in Figure 4. The module comprises a main shaft 52 upon which a first turbine 53 and a second turbine 54 are mounted. Each turbine 53,54 comprises centrifugal vanes 55 and external vanes 56 which assist in the rotation of the turbines 53,54 when exposed to wind flowing through the apparatus.

The shaft 52 is provided with a connection 55 for stacking modules together, the connection provided with a slot 61 into which a projection 57 on an adjacent module may be inserted.

The shaft 52 is provided with a sleeve (obscured) for supporting a bearing 58. The shaft 52 is further provided with a one-directional wheel 59 to allow rotation of the turbines 53,54 in one direction only. A clip 60 is used to maintain the bearing 58 in position.

hi Figure 6 a plan view of the turbines 53,54 is shown. The common shaft 52 on which both turbines 53,54 are mounted is located centrally only to the inner turbine 54 and is offset from the central axis 62 of the outer turbine 53.

In Figure 6 the vanes 56 of the outer turbine 53 may be more clearly seen, as may the vanes 56 of the inner turbine 54.

hi Figure 7 there is shown a power take off assembly 57 according to an embodiment of the present invention. The power take off assembly 57 comprises a shaft 58, a first flywheel 59, a second flywheel 60, a third flywheel 61 and a fourth flywheel 62, wherein the first flywheel 59 has a larger diameter than the other flywheels 60,61,62. The power take off assembly 57 is disposed on a common shaft 58 at a point intermediate power generation means 63 and a power input device (not shown) such as a power generation apparatus for generating power from wind or waves.

The power take off assembly 57 comprises a first clutch assembly 64 and a second clutch assembly 65, both of which are associated with the first flywheel 59. Each clutch assembly 64,65 comprises a pair of clutch plates 66 with expansion means 67

located between the clutch plates 66. The expansion means 67 illustrated in Figure 7 comprise springs. As the rotational speed of the shaft 58 increases, centrifugal forces cause the expansion means 67 to expand, forcing the clutch plates 66 to move apart. As the clutch plates 66 move apart, the second, third and fourth flywheels 60,61,62 move downward and engage the power take off means 68. The power take off means 68 comprises a plurality of flywheels 69 adapted for engagement with the flywheels 60,61,62 associated with the shaft 58 via gears 70.

The rotation of the power take off means 68 induced by the engagement between the power take off means 68 and the flywheels 60,61,62 can be used to drive an additional power generation device 71 such as a generator or the like.

As the rotational speed of the shaft 58 decreases, the expansion means 67 will cause the clutch plates 66 to contract, thereby disengaging the flywheels 60,61,62 from the power take off means 68 and also disengaging the shaft 58 from the power generation means 63.

In Figure 8 a clutch assembly 64 may be more clearly seen, hi this figure, the expansion means 67 comprises a weight 72 with a pair of pivotable extensions 73 that pivot towards a vertical position when exposed to centrifugal force, such as caused by the rotation of a shaft 58, and pivot towards a horizontal position when the shaft 58 is rotating only slowly or not rotating at all. As the pivotable extensions 73 move towards a vertical position, the clutch plates 66 are forced apart thus bringing a flywheel (not shown) into engagement with a power take off means (not shown).

In Figure 9 the expansion means 67 may be more clearly seen. The expansion means 67 comprises a central hub 74 with a pair of projections 75. Each of said pair of projections 75 is pivo tally attached to anchor points 76 mounted on respective clutch plates 66.

The expansion means 67 is provided with stop means 77 in the form of a barrier or bar preventing pivoting of the projections 75 beyond a certain point. This ensures that the clutch plates 66 do not come into close proximity with one another, which would lead

to potential damage to the expansion means 67.

In Figure 9, if the rotatable shaft (not shown) is located on the left of the expansion means 67, the centrifugal forces produced by the rotation of the shaft (not shown) will force the central hub 74 to move to the right, thereby causing the projections 75 to pivot in such a way as to cause the clutch plates 66 to move apart.

By contrast, if the rotatable shaft (not shown) is located on the right of the expansion means 67, the centrifugal forces produced by the rotation of the shaft (not shown) will force the central hub 74 to move to the left, thereby causing the projections 75 to pivot in such a way as to cause the clutch plates 66 to move towards one another, thereby bringing the clutch plates 66 closer together.

In Figure 10 an end view of the expansion means 67 is illustrated, hi this Figure it may be seen that the expansion means 67 is constructed from a pair of components 78,79, the pair of components 78,79 adapted for connection by a bolt 80 or similar fastening device through the central hub 74. The stop means 77 are positioned so as to prevent excessive pivoting of the projections 75.

In Figure 11 , an alternative embodiment of the invention is shown. The expansion means 81 comprises a first wedge 82 and an identical second wedge 83. The first wedge is connected to a first clutch plate 84 and is retained thereon. The second wedge 83 is connected to sliding means 85, the sliding means 85 adapted for sliding engagement with a second clutch plate 86. Horizontal movement of the sliding means 85 causes the surfaces 87 of the wedges 82,83 facing one another to slide over each other, thereby moving the clutch plates 84,86 closer together or further apart, depending on the direction of the horizontal movement of the sliding means 85.

In Figure 10, if the rotatable shaft (not shown) is located on the left of the expansion means 81, the centrifugal forces produced by the rotation of the shaft (not shown) will force the sliding means 85 to move to the right, thereby causing the wedges 82,83 to slide over one another, forcing the clutch plates 84,86 apart.

By contrast, if the rotatable shaft (not shown) is located on the right of the expansion means 81 , the centrifugal forces produced by the rotation of the shaft (not shown) will force the sliding means 85 to move to the left, thereby causing the wedges 82,83 to slide over one another, forcing the clutch plates 84,86 closer together.

Those skilled in the art will appreciate that the present invention may be susceptible to variations and modifications other than those specifically described. It will be understood that the present invention encompasses all such variations and modifications that fall within its spirit and scope.