Patent ID: 12196186

In this description, embodiments are shown and disclosed of the invention, by way of example only. These should by no means be interpreted or understood as limiting the scope of the present invention in any way. In this description the same or similar elements are indicated by the same or similar reference signs.

FIG.1shows a turbine1, wherein a propeller5is mounted to said turbine1, rotatable around a propeller axis P, wherein a multi piston pump6is provided, said multi piston pump6being drivable by said propeller5for pressurizing a pumping fluid. The turbine1can be a wind turbine1.

As shown inFIG.2, the multi piston pump6comprises a central part7and a drive ring8, which is inFIG.2shown as extending around the central part7. The central part7comprises a series of piston-cylinder assemblies9which are each compressible and extendible in a respective radial direction R with respect to a common central axis C, wherein each of the piston-cylinder assemblies9is directly or indirectly engageable by the drive ring8for radial compression thereof, in particular for pressurizing said pumping fluid. Each piston-cylinder assembly comprises at least a piston11and a cylinder10, the piston11being movable inside the cylinder10in the relevant radial direction R. Such movement of the relevant piston11relative to the cylinder10will lead to extension or compression of the assembly9. Extension and compression can be obtainable by movement of the piston inside the cylinder of such assembly.

It will be appreciated that inFIG.2, while only three radial directions R have been indicated by respective arrows, each piston-cylinder assembly is associated with a respective radial direction. The central axis C may substantially coincide with the propeller axis P, but that is not strictly necessary.

It will be appreciated whileFIG.2shows a particular number of piston-cylinder assemblies, a multi piston pump may comprise a different number of piston-cylinder assemblies. It will also be appreciated that piston-cylinder assemblies and/or groups thereof may be arranged parallel to each other, for example parallel when viewed perpendicular to the central axis C.

As is for example shown inFIG.2the drive ring8can have an undulating surface8A facing the central axis C, against which surface8A an end30, preferably an engagement element30A such as a wheel or bearing of each piston-cylinder assembly9runs. The undulating surface8A, having tops and valleys, when rotating the central part7relative to the ring8the ends30will periodically be forced inward, towards the central axis, compressing the relevant assembly9. After such compression the relevant assembly has to expand again, for which preferably the end30is, when so desired, maintaining contact with the surface8A. In the present disclosure biasing means12are provided in order to aid in maintaining, when desired, said contact. By using hydraulic and/or pneumatic biasing means12a biasing force can easily and effectively be controlled, as will be explained hereafter.

With reference toFIGS.3a-band4a-b, at least one9aof the piston-cylinder assemblies9is provided with a hydraulic and/or pneumatic biasing means12for biasing, at least selectively biasing, at least part of that piston-cylinder assembly9atowards engagement with the drive ring8. The hydraulic and/or pneumatic biasing means12is preferably a substantially hydraulic biasing means12. Biasing has to be understood as at least meaning providing a positive force towards or away from the drive ring8, in order to maintain engagement of for example the end30of the relevant assembly9, such as for example a wheel, and the drive ring8, or to positively force the said end30away from said drive ring8. An hydraulic and/or pneumatic biasing means12has to be understood as including any at least partly hydraulic and/or pneumatic based system allowing to provide for a force on and/or in a piston-cylinder assembly or part thereof, for forcing an end30, preferably an engagement element30A towards the surface8A of the drive ring8and/or away from said surface. Such hydraulic and/or pneumatic biasing means12can for example be or comprise a linear system, such as a piston-cylinder assembly, or a rotating system, such as a hydraulic of pneumatic motor or pump, and can be provided directly engaging the piston11and/or cylinder10of a relevant piston-cylinder assembly9or can for example be provided with linkage between the biasing means12and the piston-cylinder assembly9, such as for example mechanical or fluidal based linkage.

Said at least selective biasing is in particular substantially independent of and/or complementary to a biasing by a pressure of pumping fluid at that piston-cylinder assembly9a. Thus, it will be appreciated that, during operation, at least part of a piston-cylinder assembly9amay in fact be additionally, e.g. independently, biased by a pressure of pumping fluid at that piston-cylinder assembly9a, which additional biasing as such may however be insufficient, at least in some cases and/or at least part of the time, to engage the piston-cylinder assembly9awith the drive ring8.

The at least selective biasing is preferably such that it ensures a substantially continuous engagement of the relevant end30of the assembly9with the drive ring8. However, this is not essential. In embodiments, the at least selective biasing by the biasing means12may be stronger when engagement with the drive ring8is not yet achieved and/or weaker or substantially absent when the piston-cylinder assembly9ais engaged with the drive ring. In other words, in some embodiments, the biasing means12can promote engagement with the drive ring8without necessarily fully enforcing such engagement.

The biasing means12may comprise a hydraulic and/or pneumatic spring18and/or a hydraulic and/or pneumatic pump17, as will be elucidated further.

FIG.2shows that piston-cylinder assemblies9may be provided, e.g. each, with a respective mechanical spring25, however this is not essential. If provided, such a mechanical spring25can for example complement the biasing means12, wherein some additional biasing can be performed by the mechanical spring25. The presence of such a mechanical spring25shall not by itself be understood as to render any biasing means different from hydraulic and/or pneumatic.

By using hydraulic and/or pneumatic biasing means12in addition to or in stead of such mechanical spring25can provided the advantage that for example the biasing pressure can be reduced or removed or even reversed when compressing the relevant piston-cylinder assembly, requiring less force for such compression, whereas the biasing pressure can be provided for at a desired level when the piston-cylinder assembly9has to expand again. Thus the effectivity of the pump cq turbine can be improved, and wear can be reduced.

In embodiments, as shown inFIGS.3a-band4a-b, the biasing means12is at least partly integrated in the at least one9aof the piston-cylinder assemblies9, wherein preferably the biasing means12at least partly extends inside the at least one9aof the piston-cylinder assemblies9.

In embodiments, as shown inFIG.5, the biasing means12is at least selectively connected to at least other one9bof the piston-cylinder assemblies9for receiving a variable actuation signal therefrom, wherein the at least selective biasing is at least partly dependent on the received actuation signal. To that end, the biasing means12may be provided with a respective input14, for example a hydraulic and/or pneumatic input14(seeFIGS.3a-band4a-b), and may comprise a sensor, such as a position sensor and/or a pressure sensor system including valves21,24, as will be described.

The variable actuation signal may correspond at least partly to a variable relative position of a respective piston11bwith respect to a respective cylinder10bof the at least other one9bof the piston-cylinder assemblies9.

As an example,FIG.5shows how such an actuation signal can be relayed through a hydraulic and/or pneumatic connection16.

It will be appreciated that while inFIG.5, the piston-cylinder assemblies9aare shown substantially parallel to each other, said assemblies9acan be arranged differently with respect to each other.

In embodiments the biasing means12is configured such that the at least one9aof the piston-cylinder assemblies9is extended, at least selectively extended, when another one9bof the piston-cylinder assemblies9is compressed.

InFIG.3-6piston-cylinder assembly are shown having their radial direction R parallel. This is obviously only done for explanatory purposes and does not represent their actual position in a pump or turbine. Piston-cylinder assemblies9shown in these figures next to each other may not be next to each other in an actual pump or turbine, but for example radially opposite each other.

InFIG.5, block arrows at ends30of the pistons indicate possible piston movement directions at some exemplary moment in time. It will be appreciated that such piston movements can thus be substantially reciprocal, i.e. the sum of the piston movements can be substantially zero so that a combined volume of hydraulic and/or pneumatic operating fluid can be substantially constant, at least at a substantially stable fluid pressure. In this way, a particularly compact and efficient biasing means12or series of connected biasing means12can be provided.

In embodiments, the biasing means12is selectively operable in at least a first operating state or a second operating state, each being in particular selectable by a controller15, wherein in the first operating state, the biasing means12is configured for biasing the at least one piston-cylinder assembly9atowards engagement with the drive ring8, wherein in the second operating state, compared to the first operating state, the biasing means12is configured for less or not biasing said assembly9atowards engagement with the drive ring8or even away from said drive ring8.

An exemplary controller15is shown inFIG.5, wherein it will be appreciated that the controller15is preferably connected to or at least can communicate with one or more hydraulic and/or pneumatic elements such as those shown inFIG.5, in particular valves21. Thus, in an embodiment, the controller15may select an operating state by controlling, e.g. actuating, one or more of the valves21.

In embodiments, the hydraulic and/or pneumatic biasing means12is provided with a respective spring element18, in particular an accumulator18, wherein the biasing means is preferably further provided with a pump17for pressurizing an operating fluid in the hydraulic and/or pneumatic biasing means12. The spring element18may be a hydropneumatic spring element, for example a gas-charged accumulator18. The operating fluid itself may or may not be compressible. In case of a substantially compressible operating fluid, e.g. a gas, such a spring element may alternatively or additionally be provided by the (preferably pressurized) operating fluid itself, in particular by a volume thereof.

In embodiments, as shown inFIG.5, the multi piston pump6is configured for pumping the pumping fluid, such as for example water, especially sea water, through a respective first fluid circuit19, wherein the hydraulic and/or pneumatic biasing means12forms or is part of a second fluid circuit20which is separate from the first fluid circuit19.

In embodiments, the biasing means12is provided with a valve21for selectively depressurizing the biasing means12, at least a part thereof, at the at least one9aof the piston-cylinder assemblies9.

It will be appreciated that thus a part of the biasing means12may be depressurized while another part of the biasing means12may remain or become pressurized, wherein said part and other part may or may not be at the same piston-cylinder assembly9a. For example, as will be elucidated further, an input14of a piston-cylinder assembly9amay thus be depressurized while an inversion channel26associated with the same piston-cylinder assembly may remain or become pressurized.

In embodiments, as shown inFIGS.3a-band4a-b, the at least one9aof the piston-cylinder assemblies9comprises a first pressure chamber22and a second pressure chamber23, each having a respective variable volume which is dependent on a variable relative position of a respective piston11awith respect to a respective cylinder10a, wherein the first pressure chamber22is configured for receiving and pressurizing pumping fluid, wherein the second pressure chamber23forms part of the biasing means12. The second pressure chamber23is preferably configured such that a positive pressure in the second pressure chamber23promotes that the piston11ais moved out of the cylinder10a. Movement of a piston11into a cylinder10should be understood as meaning relative movement of the piston11and the cylinder10, such that a volume of a piston chamber of the assembly for holding pumping fluid is reduced, compressing pumping fluid therein.

While inFIGS.3a-bthe first and second pressure chambers22and23have each been indicated as a dashed area, it will be appreciated that such pressure chambers are preferably substantially hollow. During operation, such pressure chambers22,23may be filled with a fluid.

As shown, either or both of the first and second pressure chamber22and23may extend between and/or be bound by the respective piston11aand the respective cylinder10a. Alternatively, for example, the second pressure chamber23may be arranged outside the piston11aand/or outside the cylinder10a.

FIGS.3a-band4a-bshow that the first pressure chamber22and second pressure chamber23are preferably arranged concentric with respect to each other and/or with respect to the piston-cylinder assembly9a, in particular viewed in the radial direction R. In this way, pressurization forces associated with the piston-cylinder assembly9acan be well balanced with respect to the said assembly9aand/or with respect to each other.

The first and second pressure chambers22and23are preferably separate from each other, in particular substantially fluidly isolated from each other. Alternatively, in some embodiments, said pressure chambers22and23may be at least partly fluidly connected to each other, for example by a constricted fluid connection, such that a fluid pressure in the first pressure chamber22may still differ from a respective fluid pressure in the second pressure chamber23. In such latter embodiment the constriction may be controllable in order to control the pressure difference.

In embodiments, with reference toFIG.5, the first pressure chamber22forms part of the first fluid circuit19, wherein the second pressure chamber23forms part of the second fluid circuit20.

In embodiments, the biasing means12further may comprise an inversion means24for selectively biasing the at least part of the at least one9aof the piston-cylinder assemblies9away from engagement with the drive ring8, wherein preferably said biasing away from engagement is selectable by a deselection of the biasing towards engagement by the biasing means12.

In an embodiment as shown inFIG.5, the inversion means24comprises a valve21(and preferably an associated controller15) for selectively pressurizing a third pressure chamber27(seeFIGS.3a-band4a-b) which is connected to the respective piston11aand the respective cylinder10asuch that a positive pressure in the third pressure chamber27promotes that the piston11ais moved into the cylinder10a. An inversion channel26may operatively connect the valve21to the third pressure chamber27.

The third pressure chamber27is thus configured such that when it is pressurized, in particular while the second pressure chamber23is not or less pressurized, the piston11ais urged to move (further) into the cylinder10aby the pressure in the third pressure chamber27. Thus, in this way, a piston-cylinder assembly9acan be selectively disengaged from the drive ring8, while the multi piston pump6can otherwise remain operational. Such disengagement can be desirable for example when the piston-cylinder assembly is malfunctioning or when the multi piston pump6is required to run at a lower than full capacity.

In embodiments, the biasing means12comprises a hydraulic and/or pneumatic connection16between the at least one9aand at least one other one9bof the piston-cylinder assemblies9, wherein preferably a valve21is provided in the hydraulic and/or pneumatic connection16.

In this way, a substantially constant volume of operating fluid can be shared by the at least one9aand the other one9bof the piston-cylinder assemblies9, so that for example a compression of the other one9bcan cause or promote an extension of the at least one9a(and/or vice versa). Thus, as an additional advantage, a single accumulator18and a single pump17can be provided, associated with multiple, preferably all, of the piston-cylinder assemblies9.

In preferred embodiments, each of the piston-cylinder assemblies9is provided with a biasing means12for biasing, at least selectively biasing, that piston-cylinder assembly9towards engagement with the drive ring8.

In preferred embodiments, a plurality of biasing means12are provided, preferably associated with a respective plurality of piston-cylinder assemblies9, wherein said biasing means12are connected or connectable to each other, in particular connected or connectable by a common hydraulic and/or pneumatic circuit20.

In embodiments, the multi-piston pump6is configured such that during operation each piston-cylinder assembly9is repeatedly subsequently compressed by the drive ring8and extended by at least the biasing means12.

In an exemplary method of operating a turbine1and/or a multi piston pump6, an operating fluid, in particular water or a water-glycol hydraulic fluid, is provided in the hydraulic and/or pneumatic biasing means12, wherein preferably said operating fluid is pressurized. Such use of water or water-glycol can provide the advantage that any spillage of operating fluid is substantially harmless to the environment, e.g. an aquatic environment.

The disclosure is by no means limited to the embodiments disclosed in the drawings. Many amendments, variations and alternatives are possible within the disclosure. For example in a pump or turbine of the disclosure the central part can be rotated, and the drive ring can be stationary, or both the central part and the ring can be rotated. The drive ring can be provided around the central axis, engaging the inward facing ends of the piston-cylinder assemblies9in stead of the outward facing ends30. The control15can be an electronically operated control. The turbine can be a hydraulic turbine in stead of a gas operated turbine, such as a wind turbine. These and many other amendments are considered to have been disclosed herein also, including but not limited to all combinations of elements of the invention as disclosed, within the scope of the invention as presented.

LIST OF REFERENCE SIGNS

1. Turbine5. Propeller6. Multi piston pump7. Central part8. Drive ring8. Surface9. Piston-cylinder assembly10. Cylinder11. Piston12. Biasing means14. Input15. Controller16. Hydraulic and/or pneumatic connection between the at least one and the other one of the piston-cylinder assemblies17. Hydraulic and/or pneumatic pump18. Spring element19. First fluid circuit20. Second fluid circuit21. Valve22. First pressure chamber23. Second pressure chamber24. Inversion means25. Mechanical spring26. Inversion channel27. Third pressure chamber30. End30A. Engagement elementC. Central axisP. Propeller axisR. Radial direction