Background to the Invention

The present invention relates to apparatus for use in a wave energy conversion system.

Wave energy conversion system typically extract energy from waves within a body of water using at least one device deployed in the body of water that is configured to capture the energy of the waves. Such devices have previously been proposed but typically suffer from a reliance on components requiring frequent maintenance and/or poor protection while deployed in hostile environments. Additionally, such devices are typically large in size, meaning maintenance of such devices typically must be carried out offshore.

It is an object of the present invention to avoid or minimise one or more of the foregoing disadvantages.

Summary

A first aspect of the invention provides a pump device for use in a wave energy conversion system comprising a power take-off system, the pump device comprising:- at least one pump chamber; a driving chamber; a pump shaft disposed within the driving chamber; a moveable element arranged to be disposed within a body of water and arranged to move in response to the force of water acting upon the moveable element; wherein the or each pump chamber is sealed from the driving chamber by a respective flexible diaphragm; wherein the or each flexible diaphragm is connected to the pump shaft such that movement of the pump shaft moves the or each flexible diaphragm to pump fluid to the power take-off system; and wherein the moveable element is coupled to the pump shaft such that movement of the moveable element is translated to the pump shaft.

Optionally the moveable element is arranged to move in response to wave forces (optionally wave surge forces) acting upon the moveable element within the body of water.

Optionally, in a less preferred arrangement, the pump shaft is integral with or securely coupled to the moveable element. Alternatively, and preferably, the moveable element is coupled to the pump shaft by a translating coupling mechanism arranged to translate movement of the moveable element to the pump shaft.

Optionally movement of the pump shaft moves the or each flexible diaphragm to pump fluid from the or each pump chamber to the power take-off system.

Optionally the pump device is configured for use in relatively shallow bodies of water (typically between 5m-20m) (e.g. bodies of water with mean depths ranging from half to a full wavelength of waves expected in the location of use.)

Optionally the body of water is the sea. Optionally the pump device is configured for pumping sea water from the pump device to a power take-off system.

Optionally the or each pump chamber and the driving chamber are defined by a pump housing.

Optionally the or each pump chamber comprises an inlet port and an outlet port, optionally defining a flow pathway.

Optionally each outlet port converges to form a single pump exhaust port. Optionally each inlet port diverges from a single pump intake port.

Typically the or each flexible diaphragm is flexible such that movement of the pump shaft changes the volume of the or each pump chamber. Typically the or each pump chamber is arranged to draw in fluid (typically through the respective inlet port) in response to an increase in volume. Typically the or each pump chamber is arranged to pump fluid (which is typically drawn fluid) out of the pump chamber (typically through the outlet port) in response to a decrease in volume of the pump chamber.

Optionally the or each inlet port is in fluid communication with an inlet check valve and optionally the or each outlet port is in fluid communication with an outlet check valve.

Optionally each inlet check valve is adapted to at least restrict and/or prevent the passage of fluid out of the respective pump chamber through the respective inlet port. Optionally each outlet check valve is adapted to at least restrict and/or prevent the passage of fluid into the respective pump chamber through the respective outlet port. Optionally at least one or each inlet check valve and optionally at least one or each outlet check valve comprises one of (and which may be selected from) > a duckbill valve, a flapper valve or a ball check valve.

Optionally the pump device comprises a pump base adapted to anchor the pump device to a bed of the body of water. Optionally the pump base comprises at least one mechanical fixing between the pump base and bed of the body of water. Optionally the pump base comprises a gravity anchor.

Optionally, in an alternative embodiment, the pump base is attached to (optionally suspended from) a floating structure (e.g. a buoy). Optionally the floating structure is anchored to the seabed optionally via at least one mooring line.

Optionally, in a yet further alternative embodiment the pump base is fixed to a structure within the body of water (optionally a harbour wall or a jetty), optionally by at least one mechanical fixing between the structure and the pump base.

Optionally the pump shaft has an axis and is optionally axially moveable. Optionally the driving chamber comprises at least one shaft guide configured to guide axial movement of the pump shaft. Optionally the pump shaft extends through an aperture of each shaft guide. Optionally each shaft guide restricts rotational movement of the pump shaft about its axis. Optionally the pump shaft comprises at least two pump shaft segments each having a respective axis. Optionally each respective axis of the pump shaft segments are parallel. Optionally each shaft guide comprises an aperture for each pump shaft segment.

Optionally the moveable element comprises a lever, optionally having an axis. Optionally the moveable member is configured to be rotationally moveable about a driving pivot point (optionally a driving pivot connection optionally comprising a plain bearing). Optionally the moveable member (which is typically the lever) is rotationally moveable within a rotational plane orthogonal to the axis of the driving pivot point. Optionally the translating coupling mechanism translates the rotational movement of the moveable member to movement (optionally axial movement) of the pump shaft.

Optionally the moveable element comprises a biasing mechanism configured to urge the moveable element towards a predetermined position (optionally an uppermost position). Optionally the biasing mechanism comprises a buoyant portion (optionally a buoyant chamber) configured to urge the moveable element to an uppermost position.

Optionally the buoyancy of the buoyant portion is adjustable, optionally by adjusting the axial position of the buoyant portion along the axis of the lever. Optionally the buoyant portion comprises a plurality of stackable ring modules. Optionally the buoyancy of the buoyant portion is dependent on the number of stackable ring modules provided on the lever and/or optionally the size and/or mass of each stackable ring module provided on the lever. Optionally the buoyant portion comprises an inflatable bladder. Optionally the buoyancy of the buoyant portion is dependent on the mass of fluid within the inflatable bladder. Optionally the buoyant portion comprises a ballastable tank. Optionally the buoyant portion is dependent on the mass of fluid within the ballastable tank.

Optionally the moveable element comprises a force collecting portion configured to absorb a majority of the forces acting on the moveable element. Optionally the force collecting portion is axisymmetric around an axis (optionally around the axis of the lever). Optionally the force collecting portion is coaxial with the lever. Optionally the force collecting portion radially extends further than the lever. Optionally the force collecting portion is substantially cylindrical. Optionally the force collecting portion comprises at least one rounded edge. Optionally the force collecting portion is provided on an outer surface of the lever.

Optionally the force collection portion and the biasing mechanism are provided by the same structural component.

Optionally the lever comprises an upper lever segment and a lower lever segment, optionally having respective axes, connected by a force bearing mechanism adapted to bear forces acting on the lever in directions that intersect the rotational plane of the moveable member. Optionally the force bearing mechanism comprises a force bearing pivot connection (optionally comprising a plain bearing) between the upper and the lower lever segments. Optionally the upper lever segment is rotationally moveable about the force bearing pivot connection, optionally within a rotational plane orthogonal to the axis of the force bearing pivot connection.

Optionally the collecting portion is provided on the upper lever segment. Optionally the force bearing mechanism is provided above the driving pivot connection.

Optionally the force bearing mechanism is configured to urge the upper and lower lever segments to a coaxial arrangement, optionally using either or any of a force bearing magnetic coupling between the upper and lower lever segments; a spring loaded force bearing pivot connection; a coiled spring and/or a sleeve provided over the force bearing mechanism (optionally over the force bearing pivot connection) and/or any other suitable mechanism. Optionally the sleeve is an elastomeric sleeve, optionally comprising an elastomeric material such as silicone, rubber or any other suitable material.

Optionally at least one or each flexible diaphragm is one of a rolling diaphragm, a convoluted diaphragm or a flat diaphragm.

Optionally the translating coupling mechanism is actuatable between a translating configuration and a non-translating configuration. Optionally in the translating configuration, the translating coupling mechanism provides a connection between the moveable element and the pump shaft such that movement of the moveable member is translatable to the pump shaft. Optionally in the non-translating configuration, the translating coupling mechanism does not provide a connection between the moveable element and the pump shaft such that movement of the moveable element is not translatable to the pump shaft.

Optionally the translating coupling mechanism is actuated from the translating configuration to the non-translating configuration when the force acting on the translating coupling mechanism (optionally a force acting in a direction parallel to the rotational plane of the moveable element) exceeds a predetermined breaking force. Typically the translating coupling mechanism is actuated from the non-translating configuration to the translating configuration when a connection between the pump shaft and the moveable element is established.

Optionally the translating coupling mechanism comprises a magnetic translating coupling mechanism. Optionally the magnetic translating coupling mechanism comprises a first magnetic set provided on the pump shaft and a second magnetic set provided on the moveable element. Optionally the first magnetic set is provided within the driving chamber (typically within the pump housing) and optionally the second magnetic set is provided outside of the driving chamber (typically outside of the pump housing). Optionally the first magnetic set comprises a temporary magnet. Optionally the second magnetic set comprises two permanent magnet arranged at opposite ends of the first magnetic set.

Typically the magnetic translating coupling mechanism is in the translating configuration when the first and second magnetic sets are magnetically connected. Typically the magnetic translating coupling mechanism is in the non-translating configuration when the first and second magnetic sets are not magnetically connected (i.e. they are separated and/or are magnetically separated).

Typically the magnetic translating coupling mechanism is actuated from the nontranslating configuration to the translating configuration when a magnetic connection between the first and second magnetic sets is established.

Typically the predetermined breaking force is a force required to break the magnetic connection between the first and second magnetic sets. Typically the breaking force of the magnetic translating coupling mechanism is determined by properties of each magnetic set, such as the materials and quantity thereof each magnetic translating set comprises and the distance between each magnetic set.

Optionally the pump device comprises at least one securing mechanism. Typically the or each securing mechanism is configured to secure the moveable element when the translating coupling mechanism is in the non-translating configuration. The or each securing mechanism typically has a released configuration in which the moveable element is moveable in response to the forces of water acting upon the moveable element, and typically a secured configuration in which movement of the moveable element in response to the forces of water acting upon the moveable element is restricted. Optionally in the secured configuration the moveable element is engaged with the or each respective securing mechanism. Optionally in the release configuration the moveable element is disengaged with the or each respective securing mechanism. Optionally the securing mechanism secures the moveable element in a lowermost position. Optionally the securing mechanism secures the moveable element such that it is arranged substantially parallel to a surface the pump device is fixed to.

Optionally the pump device comprises a pulsation dampener configured to reduce variations in the pressure of fluid pumped to the power take-off system (typically fluid pumped from the or each pump chamber).

Optionally the pump device comprises one pump chamber. Such examples of the pump device comprise a single flexible diaphragm, a single flow pathway, a single set of ports (inlet and outlet) and a single set of check valves (inlet and outlet). In other words, the pump device optionally comprises a single-acting diaphragm pump.

Optionally, and more preferably, the pump device comprises two pump chambers. Such examples of the pump device comprise two flexible diaphragms, two flow pathways, two sets of ports (inlet and outlet) and two sets of check valves (inlet and outlet). In other words, the pump device optionally comprises a double-acting diaphragm pump. Such an example typically has the driving chamber disposed between the two pump chambers and typically has the two flexible diaphragms axially spaced from each other along the pump shaft. Optionally the two flexible diaphragms are connected at opposite axial ends of the pump shaft. A second aspect of the invention also provides a wave energy conversion system for extracting energy from waves within a body of water comprising:- a plurality of interconnected pump devices in accordance with the first aspect of the invention within the body of water; and a power take-off system for extracting energy from the movement of each moveable element.

Each pump device may be orientated such that the moveable member predominantly moves in directions parallel to the predominant direction of the waves. Optionally each pump device is orientated such that the rotational plane of the moveable member is substantially parallel with the predominant direction of the waves.

Optionally the power take-off system is a pumped storage facility comprising:- an elevated reservoir; a turbine device connected to an electrical generator arranged to convert the mechanical energy of the turbine device into electrical energy; wherein fluid released from the elevated reservoir is arranged to drive movement of the turbine device.

Optionally pumped fluid is conveyed, typically from one or more outlet port(s) and more preferably from one or more exhaust port(s) of one or more pump device(s), to the elevated reservoir using a riser.

Optionally the power take-off system comprises a control valve configured to control the flow of fluid released from the elevated reservoir.

Optionally the turbine device is hydraulically connected or optionally mechanically connected to the electrical generator. Optionally the turbine device comprises a low- head turbine (such as an Archimedes screw turbine and/or a Kaplan turbine).

Optionally the power take-off system is provided on land. Optionally the turbine device and electrical generator is disposed below ground surface level. Optionally the initial intake of fluid (optionally seawater) is taken from the body of water (optionally the sea).

Optionally fluid is passed through at least one fluid conditioning system configured to filter out debris from the fluid.

Optionally fluid pumped from each pump device converges in a delivery pipeline arranged to convey pumped fluid from each pump device to the power take-off system.

Optionally the power take-off system is connected to a return pipeline arranged to convey fluid from the power take-off system to each pump device (i.e. each inlet port and/or each pump intake port of each pump device).

Optionally the wave energy conversion system is configured to recirculate fluid pumped to the power take-off system back to the plurality of pump devices.

Optionally the plurality of pump devices are interconnected by an interconnecting pipework system typically for conveying fluid from each pump device to the delivery pipeline and optionally for conveying fluid from the return pipeline to each pump device.

Optionally the or each outlet port of each pump device and the or each inlet port of each pump device is/are connected to the interconnecting pipework system by a sealing connector. Optionally each sealing connector comprises a sealing mechanism configured to restrict the passage of fluid through the sealing connector. Optionally each sealing mechanism is actuatable to increase or decrease its sealing effect, e.g. between open and closed configurations. Optionally each sealing connector is provided with a cap adapted to restrict the passage of debris through the sealing connector when the sealing connector is disconnected from its respective pump device.

Optionally, the interconnecting pipework system is anchored to a bed of the body of water, optionally by at least one mechanical fixing between the interconnecting pipework system and the bed of the body of water or by at least one gravity anchor connected to the interconnecting pipework system.

Optionally the interconnecting pipework system comprises at least one pressure relief mechanism (typically a pressure relief valve) configured to limit the total amount of pressure within the interconnecting pipework system.

Optionally the plurality of pump devices are arranged in an array consisting of 10 or more pump devices.

Optionally the plurality of pump devices comprises at least one set of pump devices connected in series, optionally connected between the return pipeline and the delivery pipeline.

Optionally the plurality of pump devices comprises at least one set of pump devices connected in parallel, optionally between the return pipeline and the delivery pipeline.

A third aspect of the invention also provides a method for extracting energy from forces of water within a body of water, the method comprising:- providing a wave energy conversion system in accordance with the second aspect of the invention; extracting energy from the forces of water using the power take-off system.

Various embodiments and aspects of the invention will now be described in detail with reference to the accompanying figures. Still other aspects, features, and advantages of the present invention are readily apparent from the entire description thereof, including the figures, which illustrates a number of exemplary embodiments and aspects and implementations. The invention is also capable of other and different embodiments and aspects, and its several details can be modified in various respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including", "comprising", "having", "containing" or "involving" and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes.

Any discussion of documents, acts, materials, devices, articles and the like is included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention.

In this disclosure, whenever a composition, an element or a group of elements is preceded with the transitional phrase "comprising", it is understood that we also contemplate the same composition, element or group of elements with transitional phrases "consisting essentially of”, "consisting", "selected from the group of consisting of’, "including” or "is" preceding the recitation of the composition, element or group of elements and vice versa.

The various aspects of the present invention can be practiced alone or in combination with one or more of the other aspects, as will be appreciated by those skilled in the relevant arts. The various aspects of the invention can optionally be provided in combination with one or more of the optional features of the other aspects of the invention. Also, optional features described in relation to one embodiment can typically be combined alone or together with other features in different embodiments of the invention. Additionally, any feature disclosed in the specification can be combined alone or collectively with other features in the specification to form an invention.

Various embodiments and aspects of the invention will now be described in detail with reference to the accompanying figures. Still other aspects, features, and advantages of the present invention are readily apparent from the entire description thereof, including the figures, which illustrates a number of exemplary embodiments and aspects and implementations. The invention is also capable of other and different embodiments and aspects, and its several details can be modified in various respects, all without departing from the spirit and scope of the present invention.

All numerical values in this disclosure are understood as being modified by "about". All singular forms of elements, or any other components described herein including (without limitations) components of the apparatus to collect cuttings are understood to include plural forms thereof and vice versa.

Brief Description of Drawings

Fig. 1 shows a Piping and Instrumentation Diagram (P&ID) of a wave energy conversion system incorporating a first embodiment of at least two pump devices in accordance with the invention;

Fig. 2 shows a perspective view of the first embodiment of a pump device as used in Fig.1 according to the invention and also shows interconnecting pipework segments being connected thereto;

Fig. 3 shows a side view of the first embodiment of the pump device of Fig. 2 and also shows the interconnecting pipework segments being connected thereto;

Fig. 4 shows an end view of the first embodiment of the pump device of Fig. 2 when its translating coupling mechanism is in a translating configuration and also shows the interconnecting pipework segments being connected thereto and also shows the location and orientation of section line A-A;

Fig. 5 shows a plan view of the cross section through line A-A of the pump device of Fig. 4;

Fig. 6 shows a plan view of the first embodiment of the pump device of Fig. 2 and also the location and orientation of section line B-B;

Fig. 7 shows an end view of the cross section through line B-B of the pump device of Fig. 6 and also shows the location of detail view C;

Fig. 8 shows a detail view C of the pump device of Fig. 7; Fig. 9 shows a plan view of the first embodiment of the pump device of Fig. 2 and also shows the location and orientation of section line D-D;

Fig. 10 shows a side view of the cross section through section line D-D of the pump device of Fig. 9 and also shows the location and orientation of detailed view E;

Fig. 11 shows detailed view E of the pump device of Fig. 10;

Fig. 12 shows a plan view of the first embodiment of the pump device of Fig. 2 and also shows the locations and orientations of section line F-F and section line G-G;

Fig. 13 shows a detailed end view of the cross section along section line F-F of the pump device of Fig. 12;

Fig. 14 shows a detailed end view of the cross section along section line G-G of the pump device of Fig. 12;

Fig. 15 shows a plan view of an inlet valve housing of the first embodiment of the pump device of Fig. 2 and also shows some hidden details in dashed lines and also shows the location and orientation of section line H-H;

Fig. 16 shows a side view of the cross section along the section line H-H of the pump device of Fig. 15;

Fig. 17 shows an end view of the first embodiment of the pump device of Fig. 2 when its translating coupling mechanism is in a non-translating configuration;

Fig. 18 shows a plan view of a ball check valve for use in a second embodiment of the pump device and also shows some hidden details in dashed lines and also shows the location and orientation of section line l-l;

Fig. 19 shows a side view of the cross section through line J-J of the ball check valve of Fig. 18 and also shows the location of detailed view J;

Fig. 20 shows detailed view K of the ball check valve of Fig. 19;

Fig. 21 shows a plan view of two interconnecting pipework segments as shown in Fig. 2 and also shows a sealing connector and also shows the location and orientation of section line K-K;

Fig. 22 shows an end view of the cross section through line l-l of Fig. 21 ;

Fig. 23 shows a plan view of a first embodiment of a plurality of interconnected pump devices of Fig. 2 deployed in a body of water and also shows the location of detailed view L;

Fig. 24 shows detailed view L of the first embodiment of the plurality of pump devices of Fig. 23; Fig. 25 shows a second embodiment of a plurality of interconnected pump devices of Fig. 2 deployed in a body of water and also shows the location of detailed view M; and

Fig. 26 shows detailed view M of the second embodiment of the plurality of pump devices of Fig. 25.

Detailed Description

Referring now to the drawings, a Piping and Instrumentation Diagram (P&ID) of a wave energy conversion system 1 comprising at least two pump devices 20 in accordance with the invention is shown in Fig. 1. The wave energy conversion system of this example comprises a plurality of interconnected pump devices 20 disposed within a body of water 2 and also comprises a power take off system 10 located mainly onshore 3. The pump devices 20 are arranged to pump fluid (seawater in this example) to a delivery pipeline 4 via an interconnecting pipework system 70. The delivery pipeline 4 then conveys the pumped fluid to the power take off system 10. After passing through a fluid conditioning module 6, the fluid is returned to the pump devices 20 via a return pipeline 5 and the interconnecting pipework system 70, from which it can be pumped towards the power take-off system 10 again, making the wave energy conversion system 1 a closed loop system.

The power take-off system 10 is a pumped storage facility 10 comprising an elevated reservoir 11, the fluid outlet of which is in fluid communication with a fluid inlet of a fluid control valve 12, the fluid outlet of which is in fluid communication with a fluid inlet of a turbine device 13 connected to an electrical generator 14 whereby fluid entering the fluid inlet of the turbine device 13 drives the turbine rotor in rotation to rotate the rotor of the electrical generator 14 thereby generating electrical power.

Fluid pumped from the pump devices 20 is collected and stored in the elevated reservoir 11 which acts as a gravitational potential energy storage facility 11. Stored fluid can then be released down from the fluid outlet in the elevated reservoir 11 such that it passes through and drives rotational movement of the rotor of the turbine device 13 that in turn drives the electrical generator 14 to produce electrical power. The fluid (after it passes through and rotates the rotor of the turbine device 13) exits the turbine device 13 via the fluid outlet thereof and passes into a fluid inlet of the fluid conditioning module 6.

The elevated reservoir 11 is typically elevated at least 20m above sea level, however the specific height the reservoir 11 can vary depending on the properties of the site the wave energy conversion system 1 is located at. The elevated reservoir 11 may be comprise a tank arrangement or bladder arrangement depending on the properties of the site the wave energy conversion system is located at. The elevated reservoir 11 may be located below ground level onshore 3 such that it does not disturb wildlife or presents less of an eyesore above ground.

The fluid control valve 12 is configured to control the rate at which fluid is released from the elevated reservoir 11. In use, the specific released fluid flow rate at any time is typically dependent on the energy demands of the intended energy recipients (i.e. the consumers of the electrical power generated by the electrical generator 14).

The turbine device 13 typically comprises a low-head turbine suitable for low-head applications such as an Archimedes screw, a Kaplan turbine or any other suitable type of turbine. The specific turbine to be used is dependent on properties of the site the wave energy conversion system 1 is located at.

The turbine device 13 and the electrical generator 14 are typically connected mechanically (whereby their rotors are either connected directly to one another or are connected via a suitable gearbox (not shown) but in an alternatively embodiment they can be connected hydraulically via a suitable hydraulic connection system (not shown).

The fluid conditioning module 6 of this example typically comprises filtration elements (not shown) that are configured to filter out debris and marine life from fluid received from the turbine device 13 and fluid taken in from the body of water 2 (i.e. seawater in this example). This reduces the risk of blockages occurring within the wave energy conversion system 1. The fluid conditioning module 6 may be configured to draw in water from a sea chest (not shown) provided on the fluid conditioning module 6. In other examples of the invention, several fluid conditioning modules 6 can be provided at different locations across the wave energy conversion system 1.

Typically, the pump devices 20 are installed in a relatively shallow body of water, where the mean depths typically range from a half to a full wavelength of the waves expected in the location of use. Mean depths typically range between 5m-20m. When installed in the sea 2, the pump devices 20 are preferably located such that they remain fully submerged when the body of water is at its lowest astronomical tide depth. In operation, installing the pump devices 20 further away from the shore (and thus at a greater depth) provides the advantage of greater security of the pump devices (typically from vandals and/or thieves). Installing the pump devices 20 closer to the shore (and thus at a lower depth) provides the advantage of easier installation of the pump devices 20 and easier access to the pump devices 20 (i.e. to carry out maintenance).

Various views of a first embodiment of the pump device 20 according to the invention are provided in Figs. 2-17.

As best seen in Figs. 2-3, the pump device 20 of this example comprises a pump base 60 coupled to a pump housing 21 that is in turn coupled to a protruding portion 61 extending away from the pump base 60. The pump device is typically has a height of around 2m, and a width and length of around 1 m each.

The pump housing 21 comprises a T-shaped inlet connector 22 having an intake branch 22i diverging out into two outtake branches 22o (see Figs. 5 and 14) which extend away from one another in opposite directions. The pump housing 21 comprises two pathways 23 on opposing sides of the pump housing 21 , each starting from a respective outtake branch 22o of the inlet connector 22. Following from the respective outtake branch 22o of the inlet connector 22, each pathway 23 comprises an inlet valve housing 24 and a subsequent diaphragm housing 26. Each pathway 23 ends at a respective intake branch 28i of a T-shaped outlet valve housing connector 28 and converge into an outtake branch 28o of the outlet valve housing connector 28 (see Fig. 13). Each diaphragm housing 26 is connected by a shaft housing 30 disposed therebetween. The components along each pathway 23 are connected by intermediate pipes. At least one o-ring 39 (one in this example) configured to restrict fluid from leaking out of the pump housing 21 is provided where the intermediate pipes connect to the intake branches 28i of the outlet valve housing connector 28 (see Fig. 13), the outtake branches 22o of the inlet connector 22 (see Fig. 14) and each inlet valve housing 24 (see Fig. 16). Additionally, at least one o- ring seal 39 (two in this first embodiment) is provided on the outer surface of the outtake branch 28o of the outlet valve housing connector 28 (see Fig. 13) and the outer surface of the intake branch 22i of the inlet connector 22 (see Fig. 14).

For clarity purposes, Figs. 6-11 do not show the inlet connector 22, the inlet valve housings 24, the outlet valve housing connector 28 and the intermediate pipes.

As seen in Figs. 2-5, both the intake branch 22i of the inlet connector 22 and the outtake branch 28o outlet valve housing connector 28 may be connected to a respective interconnecting pipework segment 71 of the interconnecting pipework system 70 by a sealing connector 72. For clarity purposes, Figs. 6-17 do not show these connections.

In this first embodiment, the pump device 20 and the interconnecting pipework segments 71 connected thereto may be anchored to the bed of the body of water 2 by implementing a suitable number of mechanical fixings 60f (three in this first embodiment) between the pump base 60 and the bed of the body of water 2 and a suitable number of mechanical fixings 74f (two in this first embodiment) between a pipe base 74 provided to each interconnecting pipework segment 71 and the bed of the body of water 2. The pump device 20 may be fixed directly on to the bed of the body of water 2, setting the pump device 20 in a substantially vertical orientation, or directly on a wall of a structure (not shown) within the body of water 2 (e.g. a harbour wall, a jetty, etc.), setting the pump device 20 in a substantially horizontal orientation. Additionally, the pump device 20 may instead be deployed in any suitable orientation between substantially vertical and substantially horizontal.

In other examples of the invention, the pump base 60 and/or each pipe base 74 may anchor the pump device 20 and the interconnecting pipework segments 71 connected thereto by having sufficient mass to act as gravity anchors. In further examples of the invention, the pump base 60 and/or each pipe base 74 may be suspended from a floating structure (not shown) that is anchored to the bed of the body of water 2, typically by at least one respective mooring line (not shown). The specific way in which the pump base 60 and each pipe base 74 is configured to anchor the pump device 20 and the interconnecting pipework segments 71 connected thereto is largely dependent on the properties of the site the pump device is to be deployed in.

The pump device 20 also comprises a moveable element 40 which in this first embodiment comprises a lever 41 extending along a longitudinal axis. The lever 41 of this first embodiment is connected to the protruding portion 61 by a driving pivot connection 50. The driving pivot connection 50 guides rotational movement of the moveable element 40 about driving pivot connection 50 and within a rotational plane orthogonal to the axis of the driving pivot connection 50. In this first embodiment, the driving pivot connection 50 is made using a plain bearing 50.

In use, the moveable element 40 is submerged in the body of water 2, such that it is subject to wave surge forces within the body of water 2. Typically the wave surge forces cause the moveable element 40 to oscillate about the driving pivot connection 50 at a frequency determined by properties of the moveable element 40 (e.g. its length, mass, buoyancy, etc.) and properties of the environment the pump device 20 is deployed in (e.g. wind speed, wind duration, tide levels, etc.).

Typically in use, the pump device 20 is orientated such that the moveable member 40 predominantly moves in directions substantially parallel to the predominant direction of the waves. In other words, the pump device 20 is orientated such that the rotational plane of the moveable member 40 is substantially parallel with the predominant direction of the waves and in doing so the efficiency and power output of the pump device 20 is maximised in use.

Further in this first embodiment, and as shown in Fig. 4, the lever 41 comprises an upper lever segment 41 u and a lower lever segment 411 connected at their respective axial ends by a force bearing mechanism 42. The upper and lower lever segments 41 u, 411 each have a respective longitudinal axis. The lever 41 of this first embodiment, and as shown in Fig. 11 , comprises two lever branches 41b extending down from the driving pivot connection 50 and located at opposite sides of the shaft housing 30. Additionally in this first embodiment, the moveable element 40 comprises a force collecting portion 43 provided on the upper lever segment 41 u.

The force collecting portion 43 is configured to absorb a majority of the forces acting on the moveable element 40 by providing a larger surface area (larger than the surface area of the lever 41) for the forces within the body of water 2 to act on. In this first embodiment, the force collecting portion 43 is substantially cylindrical in shape and is axisymmetric around the axis of the upper lever segment 41 u. Each of the edges of the force collecting portion 43 in this first embodiment are rounded. In use, the rounded edges of the force collecting portion 43 reduce potential impact forces between the force collecting portion 43 and the pump housing 21 that typically occur during extreme weather/wave events. Other examples of the force collecting portion 43 may by shaped in any other suitable form.

Additionally, the force collecting portion 43 of this first embodiment has a buoyancy which in use, is sufficient to urge or bias the moveable element 40 towards an uppermost position. The buoyancy of the force collecting portion 43 may be adjustable in order to adjust the period of oscillation of the moveable element 40 when in use. Examples of the invention may achieve this by having the force collecting portion 43 comprise a plurality of stackable ring modules (not shown), wherein the buoyancy of the force collecting portion 43 is dependent on the number of stackable ring modules provided on the lever, and the size and/or size thereof. Other examples of the invention may instead have the force collecting portion comprise an inflatable bladder (not shown) or ballastable tank (not shown) that can be filled with fluid, such that the buoyancy of the force collecting portion 43 is dependent on the mass of fluid within the inflatable bladder/ballastable tank.

Adjustment of the period of oscillation of the moveable element 40 may also be adjusted by adjusting the axial position of the force collecting portion 43 along the axis of the lever 41.

As best seen in Fig. 5 and/or Figs. 15 and 16, each inlet valve housing 24 houses an inlet check valve 25. Additionally, the outlet valve housing connector 28 houses an outlet check valve 29 for each pathway 23. As best seen in Fig. 8, each diaphragm housing 26 in this first embodiment comprises a driving portion 26d, a pumping portion 26p and a flexible diaphragm 27 connected therebetween. In this first embodiment, each flexible diaphragm comprises a driving face 27d and an opposite pumping face 27p.

As best seen across Fig. 5 and Fig. 8, the pump device 20 of this first embodiment consists of two pump chambers 33 and a driving chamber 32, each being defined by the inner surface of the pump housing 21. Each pumping chamber 33 is hydraulically sealed and partitioned from the driving chamber 32 by the respective flexible diaphragm 27.

In this first embodiment, each pump chamber 33 is defined by the pumping face 27p of the respective flexible diaphragm 27 and the inner surface of the pump housing 21 along the respective pathway 23 (i.e. the respective outtake branch 22o of the inlet connector 22, the respective inlet valve housing 24, the pumping portion 26d of the respective diaphragm housing 26 and the respective intake branch 28i of the outlet valve housing connector 28). Further in this first embodiment, the driving chamber 32 is defined by the inner faces 27i of the flexible diaphragms and the inner surface of the pump housing 21 disposed therebetween (i.e. the driving portions 26d of the diaphragm housings 26 and the shaft housing 30).

Each pump chamber 30 comprises an inlet port 36 through which in use, fluid is drawn into the pump chamber 30. Each pump chamber 30 also comprises an outlet port 37 through which, in use, fluid is pumped out of the pump chamber 30.

As best seen in Fig. 8, the pump device 20 comprises a pump shaft 31 disposed within the driving chamber 32. In this first embodiment, the pump shaft 31 extends along a longitudinal axis and is arranged to be axially moveable back and fore along said longitudinal axis as will be described in more detail subsequently. Also in this first embodiment, the pump shaft 31 has each of its axial ends connected to a respective flexible diaphragm 27 and typically connected to the centre of the respective flexible diaphragm 27.

During operation of the pump device 20, movement of the pump shaft 31 moves the centre of and therefore flexes the flexible diaphragms 27, resulting in changes to the volumes of the pump chambers 33. For example, in relation to the configuration of the pump device 20 shown in Fig. 8, movement of the pump shaft 31 from left to right will move both of the flexible diaphragms 27 at each end of the pump shaft 31 from left to right as well. Considering just the left hand flexible diaphragm 27 as shown in Fig. 8 for the moment, said movement of the left hand flexible diaphragm 27 causes the volume of the pump chamber 33 to increase, which results in the pressure within the pump chamber 33 decreasing and that further causes fluid to be drawn into the said pump chamber 33 through the inlet port 36. Subsequently, movement of the pump shaft 31 in the other or reverse direction (i.e. from right to left) will move both of the flexible diaphragms 27 at each end of the pump shaft 31 in the other or reverse direction (i.e. from right to left as well) and again, considering just the left hand flexible diaphragm 27 as shown in Fig. 8 for the moment, said movement of the left hand flexible diaphragm 27 causes the volume of the said left hand pump chamber 33 to decrease, which in turn causes the pressure within the pump chamber 33 to increase and thus the previously drawn in fluid is now pumped out through the outlet port 37 at an increased pressure. The pump shaft 31 will thus be returned to the starting position and the cycle can therefore be repeated (with the next wave passing the moveable element 40 as will be subsequently described). The right hand flexible diaphragm 27 as shown in Fig. 8 will operate in the opposite process or cycle compared to the aforementioned left hand flexible diaphragm 27. Having each flexible diaphragm 27 connected at opposite axial ends of the pump shaft therefore allows the pump device 20 to have one pump chamber 33 drawing in fluid while the other pump chamber 33 pumps fluid out. In use, continuous reciprocating axial movement of the pump shaft 31 results in a continuous cycle of fluid being drawn into the pump device 20 and pumped out towards the power takeoff system 10.

During operation, the inlet check valve 25 is configured to restrict fluid drawn into the pump chamber 33 through the inlet port 36 from subsequently expelling out of the pump chamber 33 back through the inlet port 36. Additionally, the outlet check valve 29 is configured to restrict fluid expelled out of the pump chamber 33 through the outlet port 37 from being drawn back into the pump chamber 33 through the outlet port 37. In other words, the inlet check valve 25 and the outlet check valves 29 work to restrict the back-flow of fluid through the pump device 20. Driving volumetric changes in the pump chambers 33 using flexible diaphragms 27 advantageously provides a considerably more reliable seal between each pump chamber 33 and the driving chamber 32. This is because the seal provided by the flexible diaphragms 27 is not reliant on a dynamic sealing mechanism required to permit movement (either reciprocating or rotational movement) through the said seal; in other words, a reciprocating type seal such as a piston within a cylinder (i.e. which involves a seal moving along and sealing against e.g. an inner bore of a cylinder) is liable to wear out many factors quicker than a flexible diaphragm type seal. Dynamic sealing mechanisms (e.g. stuffing boxes and/or piston and cylinders) are more liable to leaking than static sealing mechanisms (i.e. the flexible diaphragm 27), thus implementing flexible diaphragms 27 into the pump device 20 gives the pump device 20 the very large advantage of considerably reduced maintenance requirements.

Each flexible diaphragm 27 is typically a rolling diaphragm. Utilising rolling diaphragms over other types of suitable diaphragms (e.g. flat diaphragms, convoluted diaphragms, etc.) advantageously increases the range of longitudinal axial movement of the pump shaft (and consequently the range of rotational movement of the coupled moveable member 40). In turn, this increases the maximum pressure at which fluid is pumped out of the pump device 20. Other examples of the pump device 20 may instead utilised any other suitable type of flexible diaphragm (i.e. flat diaphragms, convoluted diaphragms, etc.)

In use, the moveable element 40 is coupled to the pump shaft 31 such that movement of the moveable element 40 drives the pump device 20. This is achieved using a translating coupling mechanism 52 arranged to translate movement of the moveable element 40 to the pump shaft 31. In this first embodiment, the translating coupling mechanism 52 translates rotational movement of the moveable element 40 into movement of the pump shaft 31 along its longitudinal axis.

The translating coupling mechanism 52 of this first embodiment is a magnetic translating coupling mechanism 52 having a first magnetic set 52f comprising a magnetic material (e.g. iron, steel or any other suitable material) 52f provided on (i.e. integrally with or securely mounted to or in) the pump shaft 31 (see Fig. 8) and a second magnetic set 52s comprising two permanent magnets provided (i.e. securely mounted) on respective lever branches 41b (see. Fig. 11). Each permanent magnet in the second magnetic set 52s is orientated such that there is an attractive force between each of the permanent magnets 52s towards one another. The attractive force of each permanent magnet of the second magnetic set 52s is preferably balanced such that the load on the first magnetic set 52f is evenly distributed and sliding contact between an outside of the shaft housing 30 and the lever 41 (typically via the lever branches 41b) is made. As best seen in Fig. 8, the first magnetic set 52f is connected to the pump shaft 31 at a central point of the axial length of the pump shaft 31 within the driving chamber 32. Typically, the pump shaft 31 is configured to be non-magnetic in order to not interfere with the magnetic connection between the magnetic sets 52f, 52s. This is typically achieved by having the pump shaft 31 at least primarily comprised of non-magnetic materials such as carbon fibre, PEEK plastic, non-magnetic stainless steel 316L or any other suitable material.

Other examples of the pump device 20 may have the first magnetic set 52f comprise a permanent magnet and the second magnetic set 52s comprise a magnetic material.

As best seen in Fig. 4, the translating coupling mechanism 52 may be in a translating configuration in which the translating coupling mechanism 52 provides a connection between the moveable element 40 and the pump shaft 31 such that movement of the moveable element 40 is translatable to the pump shaft 31. As best seen in Fig. 17, the translating coupling mechanism 52 may be configured to be actuatable to a nontranslating configuration in which the translating coupling mechanism 52 does not provide a connection between the moveable element 40 and the pump shaft 31 such that movement of the moveable element 40 is not translatable to the pump shaft 31.

In this first embodiment, the magnetic translating coupling mechanism 52 is configured to disconnect the moveable element 40 from the pump shaft 31 when the force acting on the magnetic translating coupling mechanism 52 exceeds a predetermined breaking force (such as when a storm is passing over the wave energy conversion system 1). When the breaking force is exceeded, the pump device 20 is set from the translating configuration to the non-translating configuration (see Fig. 17) in which there is no magnetic connection between the two magnetic sets 52f, 52s and movement of the moveable element 40 is not translatable to the pump shaft 31. From the non-translating configuration, the moveable element 40 may continue to be moveable, such that it may be set back to the translating configuration in which there is a magnetic connection between the two magnetic sets 52f, 52s and movement of the moveable element 40 is translatable to the pump shaft 31. Typically the predetermined breaking force is a force required to break the magnetic connection between the first and second magnetic sets. In use, the magnetic translating coupling mechanism 52 may be set back to the translating configuration by an operator or by the action of the waves within the body of water 2 acting upon it.

In use, the breaking force of the translating coupling mechanism 52 will typically be exceeded during extreme weather/wave events. The magnetic translating coupling mechanism 52 acts to disconnect the moveable element 40 and the pump shaft 31 before the moveable element 40 experiences a force that could break or substantially damage any one or more than one of the components that together form the pump device 20 such as each flexible diaphragm 27 connected to the pump shaft 31.

In this first embodiment, the breaking force of the magnetic translating coupling mechanism 52 is determined by properties of each of the magnetic sets 52f, 52s, such as the materials and quantity thereof each magnetic set 52f, 52s comprises and/or the distance between each magnetic set 52s, 52f.

Other examples of the pump device 20 may comprise at least one securing mechanism (not shown) configured to secure the moveable element 40 when it is in the non-translating configuration. Each securing mechanism may be actuatable between a secured configuration, in which the securing mechanism is engaged with the moveable element 40 and restricts movement of the moveable element 40, and a released configuration, in which the securing mechanism is not engaged with the moveable element 40 and typically does not restrict movement of the moveable element 40. Typically in the secured configuration, the moveable element 40 is secured in an arrangement in which the moveable element 40 is substantially parallel with the surface the pump device 20 is fixed to (see Fig. 17), (e.g. the bed of the body of water 2 when the pump device is set in a substantially vertical orientation or the wall of the structure within the body of water 2 when the pump device 20 is set in a substantially horizontal orientation). As best seen in Fig. 8, in this first embodiment two shaft guides 34 are provided along the axial length of the pump shaft 31. Each shaft guide 34 is located at a respective connection between the respective diaphragm housing 26 and the shaft housing 30. Each shaft guide 34 comprises an aperture 34a through which the pump shaft 34 extends. In operation, each shaft guide 34 works to guide axial movement of the pump shaft 31.

In this first embodiment, each axial end of the pump shaft 31 is connected to the respective flexible diaphragm 27 (and typically the centre thereof) by a set of diaphragm plates 35d, 35p. Each set of diaphragm plates 35d, 35p comprises a driving plate 35d disposed on the driving face 27d of the flexible diaphragm 27 and a pumping plate 35p disposed on the driving face 27d of the flexible diaphragm 27. A set of fixing pins 35f are used to compress the flexible diaphragm 27 between the plates 35d, 35p and secure the plates 35d, 35d, and the flexible diaphragm 27 to the pump shaft 31.

As best seen in Fig. 8, the pump shaft 31 of this first embodiment comprises two pump shaft segments 31s, each having respective parallel axes. Each pump shaft segment 31s extends through a respective aperture 34a of each shaft guide 34. This arrangement restricts rotational movement of the pump shaft 31 relative to the pump housing 21, thereby making each connected flexible diaphragm 27 less liable to wear.

In use, the moveable element 40 may be subject to forces acting in directions that intersect the rotational plane of the moveable element 40 (in other words, forces not substantially aligned with the predominant wave direction). These forces may occur from poor alignment of the pump device 20 in the body of water 2 or more likely from refracted waves. These forces may bend the moveable element 40, causing damage to moveable element 40 and to any component of the pump device 20 connected thereto.

In this first embodiment, the force bearing mechanism 42 is adapted to bear these forces. The force bearing mechanism 42 of this first embodiment connects the upper lever segment 41 u and the lower lever segment 411 at a force bearing pivot connection 42. In this first embodiment, the force bearing pivot connection 42 comprises a plain bearing. The force bearing pivot connection 42 guides rotational movement of the upper lever segment 41 u about the force bearing pivot connection 42 within a rotational plane orthogonal to the axis of the force bearing pivot connection 42. In this first embodiment, the axis of the driving pivot connection 50 is orthogonal to the axis of the force bearing pivot connection 42.

In other examples of the pump device 20, the force bearing mechanism 42 is configured to urge the upper and lower lever segments 41 u, 411 to a coaxial arrangement. This may be achieved by using either or any of a force bearing magnetic coupling mechanism (not shown) between the upper and lower lever segments 41 u, 411, a spring loaded force bearing pivot connection (not shown), a coiled spring and/or sleeve provided over the force bearing mechanism 42 (typically over the force bearing pivot connection 42) and any other suitable mechanism. The sleeve may be an elastomeric sleeve comprising an elastomeric material such as silicone, rubber or any other suitable material...

Each inlet check valve 25 and each outlet check valve 29 comprises a suitable one way check valve and typically allows selective flow of fluid therethrough and in only one direction and, as best seen Fig. 13 and Figs. 15-16, each inlet check valve 25 and each outlet check valve 29 preferably comprises a duckbill check valve 25; 29. In examples of the invention where the pump device 20 is set in a substantially vertical orientation (i.e. fixed directly to the bed of the body of water), utilising duckbill check valves 25; 29 as opposed to a ball check valve 80 (see Figs. 20-22) advantageously reduces the vertical profile of the pump device 20, in turn allowing a longer lever 41 to be used (especially important in shallower bodies of water 2). Additionally, having a lower vertical profile reduces the turning moment of waves acting on the moveable element 40 in directions not substantially parallel with the predominant wave directions and to allow a pump device cover (not shown) adapted to cover the pump device 20 when not in use to have a lower profile. Other examples of the invention may have each inlet check valve 25 and each outlet check valve 29 comprise a flapper check valve (not shown), also providing examples of the pump device 20 with the advantage of a lower vertical profile. A second embodiment of the pump device 20 may have at least one or each inlet check valve 25 and at least one or each outlet check valve 29 comprise a ball check valve 80. Figs. 18-20 show an example of a ball check valve 80 that may be utilised in the second embodiment of the pump device 20 instead of the inlet valve housing 24, the outlet valve housing connector 28 and the duckbill check valves 25, 29 of the first embodiment of the pump device 20 of Figs. 2-17. As best seen in Fig. 19, the ball check valve 80 comprises a ball 81 (typically an elastomer covered steel ball) and a ring seat 82 both encased in a ball check valve housing 83. The ball check valve 80 further comprises an inlet port 80i and an outlet port 80o. The ring seat 82 comprises a conical aperture 85 comprising diameters that are both smaller than the diameter of the ball 81. The ball 81 is arranged to sit on the face of the ring seat 82 comprising the larger aperture diameter (in this example, the face facing the outlet port 80o). The conical ring seat 82 is fixed inside the ball check valve housing 84. An outer surface 82i of the conical ring seat 82 is provided with an o-ring seal 85 (see Fig. 20) configured to provide a seal between outer surface 82i of the ring seat 82 and an inner surface 83i of the ball check valve housing 83, meaning any fluid flowing through the ball check valve 80 must flow through the conical aperture 85.

In use, the ball check valve 80 of this example is arranged to be vertical with respect to the bed of the body of water 2. In the absence of fluid flowing through the ball check valve 80, the ball 81 sits on the ring seat 82 such that it covers the conical aperture 85.

When the force acting on the ball 81 from fluid flowing from the ball check valve inlet port 80i towards the ball check valve outlet port 80o exceeds the force of gravity acting on the ball 81, the ball 81 is lifted off of the ring seat 82, uncovering the conical aperture 85 and allows fluid to flow through the outlet port 80o of the ball check valve 80. Fluid flowing from the ball check valve outlet port 80o towards the ball check valve inlet port 80i acts with gravity to keep the ball 81 seated on the ring seat 82, and thus is restricted from passing through the conical aperture 85 and out of the ball check valve inlet port 80i.

Like the inlet check valves 25 and outlet check valves 29 of the first embodiment of the pump device 20, the ball check valves 80 utilised in second embodiment of the pump device 20 are configured to restrict the back-flow of fluid through the pump device 20.

Other examples of the pump device 20 may instead have at least one or each inlet check valve 25 and at least one or each outlet check valve 29 comprise a buoyancy ball check valve (not shown). Buoyancy ball check valves work similarly to the ball check valve 80 shown in Figs. 18-20, but are configured to have the ball urged into the conical aperture by a buoyant force instead of gravity. Other examples of the pump device 20 may comprise any other suitable check valve not already described above.

The first embodiment of the pump device 20 can be described as a double-acting diaphragm pump that comprises two pump chambers 33, two flexible diaphragms 27, two flow pathways 23, two sets of ports (inlet and outlet) 36, 37 and two sets of check valves (inlet and outlet) 25, 29. In operation, this allows for fluid to be drawn into one pump chamber 33 while fluid is pumped out of the other pump chamber 33. Other embodiments of the pump device may instead be single-acting diaphragm pumps comprising one pump chamber 33, one flexible diaphragm 27, one set of ports (inlet and outlet) 36, 37 and one set of check valves (inlet and outlet) 25, 29. Such single-acting diaphragm embodiments of the pump device 20 are not able to simultaneously draw in and pump out fluid.

In operation during extreme weather/wave events, the pump device 20 may be provided with a protective cover (not shown) adapted to protect the pump device 20 from impact from debris within the body of water 2.

In other examples of the invention, not shown in the figures, the pump device 20 may comprise two or more flexible diaphragms 27 along each pathway 23 (such that the two or more flexible diaphragms 27 along each pathway 23 are arranged in parallel in the pathway). Pathways 23 of this example typically still comprise a single set of ports (inlet and outlet) 36, 37 and a single set of check valves (inlet and outlet) 25, 29. Each flexible diaphragm 27 within a given pathway 23 may be connected to a respective pump shaft 31 (typically coupled to the moveable element 40 by a respective translating coupling mechanisms 52). Alternatively, each flexible diaphragm 27 within a given pathway 23 may be connected to a common pump shaft 31. Each pathway 23 having multiple flexible diaphragms 27 arranged in parallel advantageously increases the maximum volumetric change possible within a given pump chamber 33 (and thus the maximum pressure at which fluid is pumped out of the pump device) while making use of smaller and/or more easily sourced flexible diaphragms 27.

As best seen in Fig. 22, the sealing connector 72 of this example comprises a seal housing 75 fixed to the interconnecting pipework segment 71 via a clamp 76 comprising a bore 76b. The seal housing 75 comprises a bore 75b having an open end 75o adapted to connect with the pump device 20 (in the example seen in Figs 13-14, either via the intake branch 22i of the inlet connector 22 or the outtake branch 28o of the outlet valve housing connector 28) and a closed end 75c sealed by a sealing mechanism 73 provided within the seal housing 75. A seal housing perforation 75p located between the open and closed ends 75o, 75c of the seal housing 75 extends through the seal housing 75. The interconnecting pipework segment 71 comprises an interconnecting pipework segment perforation (not shown) typically encased in the clamp 76 extending through the interconnecting pipework segment 71. The sealing connector 72 of this example is arranged such that the seal housing 75 and the interconnecting pipework segment 71 are in fluid communication with each other via the bore 75b of the seal housing 75, the seal housing perforation 75p, the bore 76b of the clamp 76 and the interconnecting pipework segment perforation 71 p.

Additionally, an outer surface of the sealing mechanism 73 is provided with at least one o-ring seal 73s (two in this example) configured to restrict the passage of fluid through the bore 75b of the seal housing 75 past the sealing mechanism 73. The clamp 76 of this example is provided with at least one o-ring seal 71s (two in this example) arranged to engage with an outer surface of the interconnecting pipework segment 71 encased in the clamp 76 and configured to restrict fluid from leaking out of the sealing connector 72. The clamp 76 of this example is additionally provided with at least one o-ring seal 75s (there are two seals 75s, one at opposite ends of the seal housing perforation 75p in this example) arranged to engage with an outer surface of the seal housing 75 and configured to restrict fluid from leaking out of the sealing connector 72. In this example, the sealing mechanism 73 comprises a spring loaded piston 73 configured to be moveable within the bore 75b of the seal housing 75 such that the sealing connector 72 is actuatable between an open configuration and a closed configuration. Fig. 22 shows the sealing connector 72 in the open configuration, in which the spring loaded piston 73 is compressed such that the spring loaded piston does not cover the seal housing perforation 75p. In the closed configuration, the spring loaded piston 73 will be at least partially released such that the spring loaded piston 73 at least partially covers the seal housing perforation 75p, thereby restricting the passage of fluid through sealing connector 72.

In use, the sealing connector 72 is typically set to the open configuration when the pump device 20 connected thereto is operating. Additionally, the sealing connector 72 is typically set to the closed configuration when a fault in the pump device 20 connected thereto is detected and the said pump device 20 needs to be disconnected from the wave energy conversion system 1. Typically, the sealing connector 72 will remain in the closed configuration while the said sealing mechanism 73 is disconnected from the said pump device 20. While the said pump device 2 is disconnected from the sealing connector 72, the sealing connector 72 may be provided with a cap adapted to restrict the passage of debris through the sealing connector 72 (typically while the sealing connector 72 remains submerged in the body of water 2).

Typically, a pressure relief mechanism (not shown) provided between the outtake branch 28o of the outlet valve housing connector 28 and the respective sealing connector 72 may be configured to limit the amount of pressure being pumped out of the respective pump device 20.

Additionally, each pump chamber 33 may be in fluid communication with a pulsation dampener 38 (see Fig. 1) configured to reduce variations in the pressure of fluid pumped out of the pump device 20 that are typically caused by fluctuations in the flow of fluid in the pump device 20. The pulsation dampener 38 may be connected between the outtake branch 28o of the outlet valve housing connector 28 and the respective sealing connector 72. Fig. 23 shows a first embodiment of a plurality of interconnected pump devices 20 of Fig. 2 deployed in the body of water 2. The first embodiment of the plurality of pump devices 20 are connected by the interconnecting pipework system 70 that is also deployed in the body of water 2.

The plurality of pump devices 20 in this first embodiment are arranged in an array comprising four rows 70r of ten pump devices 20 interconnected by respective interconnecting pipework segments 71. In this example, each row runs substantially parallel to a shoreline 7. Other examples of the plurality of pump devices 20 may have any other suitable number of rows comprising any other number of interconnected pump devices 20. Typically, each row 70r comprises an intake line 70i comprising a connected line of interconnecting pipework segments 71 connected to the intake branch 22o of the inlet connector 22 of each pump device 20 in the row 70r. Additionally, each row 70r typically comprises an outtake line 70o comprising a connected line of interconnecting pipework segments 72 connected to the outtake branch 28o of the outlet valve housing connector 28 of each pump device 20 in the row.

In this embodiment, the left hand end of each row (typically the outtake line 70o of each row) is typically connected to the delivery pipeline 4. Further in this embodiment, the right hand end of each row (typically the intake line 70i of each row) is typically connected to the return pipeline 5. The connections between the interconnecting pipework system 70 and the delivery pipeline 4 and between the interconnecting pipework system 70 and the return pipeline are not shown for clarity purposes.

As best seen in Fig. 24, each pump device 20 in the first embodiment of the plurality of pump devices 20 is orientated such that the moveable member 40 predominantly moves in directions substantially perpendicular to the shoreline 7 (i.e. in directions substantially parallel to the predominant direction of the waves). In other words, the rotational plane of the moveable member 40 is aligned to be substantially perpendicular with the shoreline 7 (i.e. is aligned in directions substantially parallel to the predominant direction of the waves). In doing so, the efficiency and power output of each pump device 20 is maximised in use. In operation of this first embodiment, a wave (either incoming or receding) within the body of water 2 will act on each row 70r at a substantially different times. Doing so causes the flow of fluid out of each row 70r to peak at different times (i.e. in different phases), thus resulting in a more even flow of fluid through the delivery pipeline 4.

Fig. 26 shows a second embodiment of a plurality of interconnected pump devices 20 of Fig. 2 deployed in the body of water 2. The second embodiment of the plurality of pump devices 20 is relatively similar to the first embodiment of the plurality of pump devices 20 shown in Figs., and thus similar components and features to those of the plurality of pump devices 20 are unless otherwise subsequently described, operate in a similar manner and therefore may not be described again.

In this second embodiment, each row 70r of pump devices 20 is arranged to run substantially perpendicular to the shoreline 7.

In this second embodiment, the lower end of each row 70r (typically the outtake line 70o of each row) is typically connected to the delivery pipeline 4. Additionally in this embodiment, the upper end of each row 70r (typically the intake line 70i of each row) is typically connected to the return pipeline 5. Similarly to the first embodiment of the plurality of pump devices 20, the connections between the interconnecting pipework system 70 and the delivery pipeline 4 and between the interconnecting pipework system 70 and the return pipeline are not shown for clarity purposes.

In operation of this second embodiment, a wave (either incoming or receding) within the body of water 2 will act on each pump device 20 within a given row 70r at a substantially different time. Doing so causes the flow of fluid out of each pump device 20 within the said row 70r to peak at different times (i.e. in different phases), thus resulting in a more even flow of fluid out of the said row 70r into the delivery pipeline 4.

Other embodiments of the interconnecting pipework system 70 may comprise intake lines 70i and outtake lines 70o comprising of a single continuous pipe (not shown) instead of interconnecting pipework segments 71. Other embodiments of a plurality of interconnected pump devices 20 may be assembled onshore as a cluster (not shown) (i.e. an array comprising more than one row and more than one column). Each cluster may comprise an inlet port (not shown), through which fluid can then flow to each pump device 20 of the respective cluster, and an outlet port (not shown), through which fluid pumped from each pump device 20 of the respective cluster may be exhausted.

The inlet port of a given cluster may either be connected to the return pipeline 5 or an adjacent cluster (not shown) while the outlet port of said given cluster may either be connected to the delivery pipeline 4 or another adjacent cluster (not shown) and may be so connected either directly thereto or via an additional pipe network ((not shown) but which in certain embodiments could comprise a hollow tubular frame (not shown) to which the rest of the cluster is mounted. Such connections to an adjacent cluster may be made using articulated joints, allowing relative movement between the clusters and pipeline 4, 5 while deployed in the body of water 2.

During assembly of the plurality of pump devices 20, each row 70r or cluster may be assembled onshore 3, from which the row 70f or cluster may be deployed into the body of water and connected to the delivery pipeline 4, the return pipeline 5 and/or an adjacent cluster. During deployment, each row 70r or cluster (or additional pipe network) may be filed with air, giving said row 70r or cluster or additional pipe network thereof sufficient buoyancy to be towed to a desired position in the body of water 2. Each row 70r or cluster may then be fixed to the seabed using one or more suitable fixing, anchoring or mooring arrangements (not shown).

During operation, each row 70r or cluster or pipe network may be injected with air in order to supress surges in pressure pumped out of each row 70r or cluster or additional pipe network (i.e. like the pulsation dampener of Fig. 1).

Consequently, embodiments of the present invention have the great advantage that they provide an array of cost effective pump devices 20 which require minimal maintenance and relatively high aggregated power output in terms of pressurised fluid which can be pumped to the pumped storage facility 10 and specifically to the elevated reservoir 11 for use in generating electricity or other power as and when required. Modifications and improvements may be made to the embodiments hereinbefore described without departing from the scope of protection.

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