WO2017095347A1

WO2017095347A1 - Wave energy converter

Info

Publication number: WO2017095347A1
Application number: PCT/TR2016/050414
Authority: WO
Inventors: Yalcin ARISOY
Original assignee: Dokuz Eylul Universitesi Rektorlugu
Priority date: 2015-12-03
Filing date: 2016-11-01
Publication date: 2017-06-08

Abstract

It is a mechanical system that can be implemented to off-shore floating or stationary platforms, that transmits the power obtained from a power source such as a wave energy converter to another application such as an electrical generator, that serves to obtain power by utilizing wave motion which is a discontinuous oscillatory motion, that works by the "Objects Activated by Waves" principle and that enables integration of a plurality of Wave Energy Converters (WECs) to a single wave energy production system.

Description

WAVE ENERGY CONVERTER

Technical Field of the I nvention

The invention is a system that can transfer power obtained from power sources such as a wave energy converter (WEC) to another system like an electrical generator and that can be implemented to floating or stationary platforms and it is related to Power Take-Off System ( PTO) . I t is suitable for wave energy converters (WECs) that operate by "Oscillating Water Column Principle" and "Objects Activated by Waves Principle" . Since power obtained through wave motion, which is a discontinuous oscillation motion, has a limited magnitude, use of only one wave energy converter (WEC) is not enough in terms of energy production. Therefore, the proposed Power Take-Off System ( PTO) that enables use of more than one wave energy converter (WEC) gains importance in wave energy production.

Background of the I nvention

Many proposals and drafts have been prepared for utilization of wave power. I t is possible to classify the existing systems with respect to positioning in shoreline or offshore (such as "Shoreline" or "Off-shore devices") as well as classifying with respect to their working principles. I n general, existing systems are fall within main groups such as pneumatic, hydraulic/reciprocating, mechanical and linear magnetic. Systems developed to utilize wave energy face various problems. Difficulties such as very high maintenance and repair costs in mediums like seawater, requirement to use sea water resistant materials in order to prevent corrosion, requirement to use a generator suitable for variable speeds due to unique nature of wave motion, sealing of systems in sea water (in mechanical and electronic systems, preventing water from entering into the system and at the same time preventing oils in the system from leaking to sea water) are the main problems of these systems. These kinds of systems are designed to cover large areas since wave energy propagates widespread on sea surface. This causes the initial investment cost to increase. On the other hand, as in the wind energy, wave energy has a stochastic nature depending on the meteorological and oceanographic conditions and changes with geographic features. Therefore, any system that depends on wave energy (existing and future-developed ones) faces all the above-mentioned problems to different extents. When examined in more detail, in the existing systems, energy production is provided by connecting wave energy converter (WEC) units to each independent generator by mechanical arms. I n case separate units are connected to one generator, additional friction forces emerge due to additional gears. This causes the system to become heavier and increases the initial investment cost. I n the proposed system, more than one wave energy converter (WEC) units can be connected to a single generator through a power take-off system via cables (ropes) . I n the proposed power take-off system, using cables instead of mechanical arms enables the wave energy production system to become lighter.

Brief Description of the I nvention

Present invention related to wave energy production system is a Power Take-Off System ( PTO) designed to eliminate above mentioned disadvantages and bring new advantages to the related technical field. The proposed Power Take-Off System ( PTO) mainly consists of a pulley that is mounted on a main shaft and that has unidirectional rotation-limited cogs. The number of the said cogs is the same as the number of wave energy converter (WEC) units to be used. The other end of each cable wound to the pulley is connected to the wave energy converter (WEC) unit. Movement and direction change of the cables are carried out by reels. The advantages of the proposed system are that:

a) I t decreases the initial investment cost since many wave energy converter (WEC) units can be connected to one generator

b) Total weight of the system is decreased due to use of cables and reels instead of mechanical arms

c) Friction losses are decreased due to use of cables and reels instead of mechanical arms and gears and therefore efficiency is increased

d) The system has more flexibility since the main shaft can be designed as a horizontal shaft on floating platforms and as a vertical shaft in the wind turbine tower (base) .

The object of the invention is to produce energy by utilizing wave energy. Another object of the invention is to create additional energy capacity when implemented to wind turbine platforms.

Yet another object of the invention is to install on floating (non-bottom founded) platforms, on platforms installed to wind turbine towers and on breakwaters. Another object of the invention is to enable use of more than one wave energy converters (WEC) .

Another object of the invention is more utilization of the renewable energy sources.

Another object of the invention is to decrease maintenance and repair costs in seawater medium .

Another obj ect of the invention is to prevent corrosion in the systems and to prevent water from entering into mechanical and electronic parts.

I n order to achieve all the objects stated above and ensued by the detailed description given below, the present invention is a is a system that can transfer power obtained from power sources such as wave energy converters (WECs) to another system like an electrical generator and that can be implemented to floating or stationary platforms and it is related to power take-off system ( PTO) .

Said power take-off system is characterized in that it comprises: floating off-shore platform that carries the system , that is connected to the seabed by concrete anchor blocks, of which the movement is limited ; floating platform that carries the system which is one of the offshore platforms; in case that a floating platform is used, anchor blocks which is the concrete block mounted on the seabed used for anchoring to the sea-bed ; steel cable that connects the floating platform and the anchor blocks; the platform that is one of the off-shore platforms and that is installed to the off-shore wind turbine towers to provide additional energy capacity; buoy; modular wave energy converter (WEC) that is used to convert wave energy and that is of blade wheel or another type; the channel that is the space in which the wave energy converters (WEC) mounted in the platform are installed ; the cable that transfers the power created during the wave pass in the wave energy converter (WEC) unit to the shaft ; the roller chain (sprocket chain) that transfers the power created during the wave pass in the wave energy converter (WEC) unit to the shaft ; the v-belt that transfers the power created during the wave pass in the wave energy converter (WEC) unit to the shaft ; the lever arm that transfers the force created by the wave energy converter (WEC) to the cables; the reel that changes the direction of the cable transferring power between the wave energy converter (WEC) unit and the main shaft and that decreases the friction ; the pulley that transfers the power obtained from each wave energy converter (WEC) unit to the shaft, that transfers power to the shaft during forward motion and that can freely rotate to the reverse direction ; the generator that converts mechanical energy to electrical energy; the shaft that transmits the rotating motion to the generator and on which carries as many pulleys as the number of wave energy converters (WEC) ; the freewheel (one way clutch) which is the gear that allows the pulley to rotate in one direction and that transfers the power to the pulley during rotation in the reverse direction ; the counter balance weight that reverses the pulley for the next wave pass; and the reduction gear that enables perform ing revolution adj ustments by gear systems. A preferred embodiment of the invention has a plurality of wave energy converters (WECs) mounted on a single shaft in a system that operates on "Objects Activated by Waves" principle.

Another preferred embodiment of the invention uses a lever arm which comprises at least one component and that transfers the linear motion (in case a buoy type wave energy converter (WEC) is used) or angular rotation motion (in case a blade wheel type wave energy converter (WEC) is used) to the cables as pulling .

Yet another preferred embodiment of the invention uses a lever, which comprises at least one component as the lever arm and that transfers the linear motion to the cables as pulling in case a buoy type wave energy converter (WEC) is used.

Another preferred embodiment of the invention has a structure that operates without a lever arm , a lever or a crowbar in case roller chains are used instead of cables.

A preferred embodiment of the invention has a structure that operates without a lever arm , a lever or a crowbar in case v-belts are used instead of cables.

A preferred embodiment of the invention has polyester cables depending on the structure and size of the system that transfers the power created on the plurality of wave energy converter (WEC) units during wave pass to the main shaft connected to the energy- producing generator. A preferred embodiment of the invention has steel cables depending on the structure and size of the system that transfers the power created on the plurality of wave energy converter (WEC) units during wave pass to the main shaft connected to the energy-producing generator.

A preferred embodiment of the invention has roller chains depending on the structure and size of the system that transfers the power created on the plurality of wave energy converter (WEC) units during wave pass to the main shaft connected to the energy-producing generator.

A preferred embodiment of the invention has V-belts depending on the structure and size of the system that transfers the power created on the plurality of wave energy converter (WEC) units during wave pass to the main shaft connected to the energy-producing generator. Another preferred embodiment of the invention has reels that enable direction change of the power transm itting cables on the platform depending on the position of the wave energy converter (WEC) units.

Another preferred embodiment of the invention has a pulley that transfers the force carried by the power transmitting cables to the main shaft.

Another preferred embodiment of the invention has cables of which one end is connected to the wave energy converter (WEC) unit and the other is connected to the pulley. Another preferred embodiment of the invention has a structure that cables which are power transmission components are used as V-belts continuously wound around the wave energy converter (WEC) vertical shaft and the pulley in case of using blade wheel type wave energy converters (WEC) instead of buoy type wave energy converters (WECs) . Another preferred embodiment of the invention has a structure that cables which are power transmission components are used as roller chains continuously wound around the wave energy converter (WEC) vertical shaft and the pulley in case of using blade wheel type wave energy converters (WEC) instead of buoy type wave energy converters (WECs) . I n another preferred embodiment of the invention ; 3-4 cm wide, circular, single groove pulleys are installed side by side on the main shaft and the number of the pulleys is the same as the number of wave energy converter (WEC) units on the off-shore platform in the wave energy production system .

I n another preferred embodiment of the invention , the connection of the pulleys with the main shaft is not a rigid connection and there is a unidirectional rotating freewheel (one way- clutch) between the pulley and the shaft. I n another preferred embodiment of the invention, even though they are installed side by side on a single main shaft depending on the wave power acting on the wave energy converter (WEC) unit connected to each pulley, there is a freewheel (one way-clutch) between the pulleys and the main shaft that enables independent movement of the pulleys. Another preferred embodiment of the invention has one horizontally used main shaft.

Another preferred embodiment of the invention has one vertically used main shaft .

Another preferred embodiment of the invention has a main shaft that partially rotates between ¼ and ½ revolutions in each wave pass depending on the buoy displacement of the wave energy converter (WEC) unit or rotation of the blade wheel and diameter of the pulley.

Another preferred embodiment of the invention has a main shaft that regularly rotates via superposition of the partial rotations in different phases and magnitudes applied by the use of plurality of wave energy converter (WEC) units.

Another preferred embodiment of the invention has a counter balance weight used in the system with buoys.

Another preferred embodiment of the invention has a structure in which there is no lever arm used to transfer linear motion of the buoy to the cables in the case that the buoy is arranged to have an annular shape and an additional reel is installed under the platform . Another preferred embodiment of the invention has a pulley on which a freewheel (one way clutch) is installed in the center.

Another preferred embodiment of the invention has a wave energy converter (WEC) having a buoy system or wheel blade system .

Another preferred embodiment of the invention has a counter balance weight that prepares the pulley ready for the next wave pass in case of using cables as the power transmission component.

Brief Description of the Figures

The figures and related descriptions used for better understanding of the Power Take-Off System ( PTO) developed by the invention are given below. I n the figures, the power take- off system is shown as a separate system inside the wave energy production system.

Figure 1 shows a general panoramic view of the platform that carries the wave energy production system . Figure 2 shows the plan view and details of the Power Take-Off System (PTO) Figure 3 depicts the parts of the Power Take-Off System ( PTO) .

Figure 4 shows the connection of modular wave energy converter (WEC) units with the Power Take-Off System (PTO) in the wave energy production system.

Figure 5 shows the side view of the Power Take-Off System ( PTO) and connection with the buoy type wave energy converter (WEC) units when wave energy converter (WEC) units with buoys are used.

Figure 6 shows plan and sectional views of modular wave energy converters (WEC) . Description of the Elements/ Components/ Parts of the I nvention

I n order to better describe the Power Take-Off System ( PTO) developed by this invention and the position of this system in a wave energy production platform, the parts and components stated in the figures are enumerated and what each number corresponds to is stated below.

The parts with number 7, 8, 9, 10, 1 1 and 12 are the main parts that are important and directly related to the invention. The other parts are the auxiliary parts that are required if the proposed power transmission system is used in a wave energy production system.

1 . Off-shore platform

1 .1 Floating platform

1 .2 Platform installed to a wind turbine tower

2 Anchor block

3 Steel cable

4 Channel

5 Wave Energy Converter (WEC)

5.1 Buoy system

5.2 Wheel blade system

5.3 Plan views

5.4 Sectional views

6 Lever arm

7 Cable

8 Reel

9 Pulley

1 0 Freewheel (one way clutch)

1 1 Main shaft

1 2 Counter balance weight

1 3 Reduction Gear

1 4 Generator Detailed Description of the I nvention

I n this detailed description, the invention is described through non-limiting examples for better understanding of the subject. Thus, the structural components that constitute the Power Take-Off System (PTO) are described.

Referring to Figure 1 , a general panoramic view of the platform that carries the wave energy production system is shown. The off-shore platform (1 ) that carries the wave energy converters (WEC) (5) and the Power Take-Off System (PTO) is in the form of a floating platform (1 .1 ) connected to the seabed by anchor blocks (2) or in the form of a platform (1 .2) installed to an off-shore wind turbine tower. The floating platform (1 .1 ) is connected to the seabed by concrete anchor blocks (2) and steel cables (3) with restricted motion. I t consists of vertical hollow channels (4) that enable up and down movement of the buoy formed in the off-shore platform (1 ) or that are the vertical spaces in which the wheel blade type wave energy converters (WEC) are installed and it consists of steel cables (3) that connect the off-shore platform (1 ) and the anchor blocks (2) . The platform (1 .2) installed to the off-shore wind turbine tower only consists of the channels (4) .

Referring to Figure 2, the plan view and details of the Power Take-Off System ( PTO) are shown. I t consists of the lever arm (6) that transmits the linear motion of the Wave Energy Converters (WEC) (5) to the cables (7) ; the cables (7) that transmits the force created during wave pass to the main shaft (1 1 ) ; the reel (8) that serves as the direction changer during conveyance of the cable (7) between the wave energy converter (WEC) (5) and the pulley (9) ; the pulley (9) that is connected to the cable which transfers the buoyancy force created during wave pass to the shaft (1 1 ) , that transmits power to the main shaft (1 1 ) during forward motion and that can freely rotate in the reverse direction; the freewheel (one way clutch) (10) located in the center of the pulley (9) and that can unidirectionally rotate; the reduction gear (13) that enables revolution rate adjustment by gear systems; and the generator (14) that converts the mechanical energy to the electrical energy.

Referring to Figure 3, the parts of the Power Take-Off System ( PTO) are shown. I t consists of the pulley (9) which the cables (7) forming the power transmission system are connected, that transmits the buoyancy force created during wave pass to the main shaft (1 1 ) , that transmits power to the main shaft (1 1 ) during forward motion and that can rotate in the reverse direction; the freewheel (one way clutch) (10) located in the center of the pulley (9) and that can unidirectionally rotate (when the unit rotates in one direction the gear rotates freely, but when a torque is applied in the opposite direction the gear rotates with the pulley) ; and the main shaft (1 1 ) on which as many pulleys (9) as the number of wave energy converters (WECs) (5) are mounted and that transmits the created rotation motion to the generators (14) .

Referring to Figure 4, the connection of the modular wave energy converter (WEC) (5) units to Power Take-Off System ( PTO) is shown in the wave energy production system . The energy production system comprises, optionally, structurally different buoyancy system (5.1 ) or wheel blade system (5.2) that rotates around a vertical axis.

Referring to Figure 5, when buoyancy type wave energy converter (WEC) (5) units are used, side view of the Power Take-Off System ( PTO) and its connection details to buoyancy type wave energy converter (WEC) (5) units are shown. The connection details of the channel (4) , buoyancy type wave energy converters (WECs) (5) , the lever arm (6) , the cables (7) , the reel (8) , the pulley (9) , the counter balance weight (12) , the reduction gear (13) and the generator (14) are shown.

Referring to Figure 6, plan and sectional views of the two modular wave energy converters (WECs) (5) are shown. The plan views (5.3) and sectional views (5.4) of the wave energy converters (WECs) (5) that convert wave energy to mechanical energy by utilizing wave energy are shown.

I n the light of the information given above, the Power Take-Off System ( PTO) works as described below. The Power Take-Off System ( PTO) depends on the principle that a plurality of independent pulleys (9) that carry (on their centers) freewheels (10) which unidirectionally rotate between the main shaft (1 1 ) and the pulley (9) are installed on to a single main shaft (1 1 ) . There is a cable (7) wound to each pulley (9) and on the other end of this cable (7) there is a wave energy converter (WEC) (5) . The wave energy converter (WEC) (5) may comprise of buoys filled with air and used for creating the hydrostatic buoyancy force during wave pass or wheels and blades mounted around a vertical shaft or another system that works by the "objects moved by waves" principle. I nside the off-shore platform (1 ) , there are as many vertical cylindrical hollow channels (4) as the number of pulleys (9) on the main shaft (1 1 ) . I nside the cylindrical hollow channels (4) , there are wave energy converters (WECs) (5) . The structural components and working principle of the proposed Power Take-Off System ( PTO) differ depending on the wave energy converter (WEC) (5) to which it is connected (i.e. depending on the wave energy converter selected in the wave energy production system) . The working principle of the proposed Power Take- Off System ( PTO) is described below for the wave energy converter (WEC) (5) units for both the buoyancy system (5.1 ) and the wheel blade system (5.2) .

I n a buoy type wave energy converter (WEC) (5) , the buoys have the capability of moving up and down via passage of waves. The buoy inside the channel (4) which is a cylindrical hollow space pulls the cable (7) connected to it during its upside movement by the buoyancy force of the water. Depending on the wave height acting on it, the displacement of the buoy is transmitted to the pulley (9) , thereby to the main shaft (1 1 ) through the lever arm (6) connected to the buoy and the cable (7) connected to the lever arm . Each displacement of the buoy corresponds to between ¼ and ½ revolution movement of the main shaft (1 1 ) depending on the pulley (9) diameter. The buoy that rises during the pass of wave front transmits power to the main shaft (1 1 ) ; and during the downward movement of the buoy, due to the freewheel (10) gear, the pulley (9) can easily move to the reverse direction without obtaining any power and gets ready for the next rising cycle. I n the falling period of the buoy, the counter balance weight (12) connected to the related pulley (9) at the reverse side retracts the related cable (7) and prepares the pulley (9) for the next cycle. The counter balance weight (12) is determined depending on the system size and the friction forces created during rotation of the cables (7) around the pulley (9) and the reels (8) .

I n the case that the proposed Power Take-Off System ( PTO) is used with a wave energy converter (WEC) (5) units that utilize wheel blades rotating around an axis, even though they are mainly the same, there are some differences in the structural components and the working principle. I n this case, the lever arm (6) is mounted perpendicular and articulated to the vertical axis of the wave energy converter (WEC) (5) . The vertical shaft of the wave energy converter (WEC) (5) that is forced to rotate by the horizontal momentum of the wave during pass of the wave front forces the lever arm (6) to rotate and thus the wave power is transmitted to the pulley (9) and therefore to the main shaft (1 1 ) through the cable (7) connected to the lever arm (6) in a way similar to the buoyancy type system (5.1 ) . The lever arm's (6) getting ready for the next wave pass is accomplished by the counter balance weight (12) . The mechanism that permits reverse rotation of the hinge of the lever arm (6) is enabled by a gear of which the movement is limited to only one direction similar to the freewheel (10) gear located in the center of the pulley (9) . I n the case of using a vertical axis wave energy converter (WEC) (5) , it is possible to construct the system without using the lever arm (6) and the counter balance weight ( 1 2) . I n such designs, it is required to use geared pulley (9) , geared V-belt or roller chains. However, in this case, a second freewheel (one way clutch) (1 0) gear is needed on the axis of the wave energy converter (WEC) unit. The geared V-belt or the roller chain is wound around the pulley (9) on the main shaft ( 1 1 ) and the fixed gear on the vertical axis of the wheel blade type wave energy converter (WEC) (5) .

The force acting on the wave energy converter (WEC) (5) by the oscillatory accelerated wave motion , the force acting on the cable (7) which the wave energy converter (WEC) (5) units pulls, the force acting on the pulley (9) by the cable (7) and the force acing on the main shaft ( 1 1 ) by the pulley (9) has a characteristic that changes in time. However, since there are many wave energy converters (WEC) (5) inside the off-shore platform ( 1 ) and wave fronts reach these units at different times, the wave forces that act on to each wave energy converter (WEC) (5) apply force to the main shaft (1 1 ) at different times. Since the total power acting on the main shaft ( 1 1 ) is the superposition of the forces applied by the wave energy converters (WECs) (5) with different phases and magnitudes, it is provided that the angular velocity of the main shaft (1 1 ) is regular, that is close to constant. I n the wave energy production system , each cable (7) is connected to the main shaft ( 1 1 ) via a 3-4 cm wide pulley; therefore, it is enabled to connect a large number of wave energy converters (WECs) (5) to the system . By using cables (7) and reels (8) during power transm ission, it is possible to design the main shaft ( 1 1 ) vertically without using any additional gears and without additional frictions. I n the case of a platform (1 .2) installed to the wind turbine tower, it is possible to easily install the main shaft ( 1 1 ) vertically inside the tower of the wind turbine having 4-5 m diameter.

Claims

A Power Take-Off System (PTO) which can be applied to floating or stationary platforms, which can transmit the power obtained from a power source in general and specifically from a wave energy converter (WEC) (5) to another application, and which is suitable for wave energy production systems on which a large number of wave energy converters (WEC) (5) can be integrated, characterized by comprising;

• an off-shore floating platform (1) that carries the system, that is anchored by concrete blocks and that can float but has restricted movement,

• a floating platform (1.1) that carries the system and that is one of the off-shore platforms (1),

• In case of using the floating platform (1.1), an anchor block (2) that is the concrete block positioned on the seabed and that anchors the platform,

• a steel cable (3) that connects the floating platform (1.1) and the anchor blocks

(2),

• a platform (1.2) installed to the off-shore wind turbine tower, that is one of the off-shore platforms (1) and that provides additional energy capacity,

• a modular wave energy converter (WEC) (5) of buoy, wheel blade or other type that converts the wave energy,

• a hollow channel (4) formed in the off-shore platform (1) in which the wave energy converters (WEC) (5) are installed,

• a cable (7) that transmits the force created in the wave energy converter (WEC) (5) during wave pass to the main shaft (11),

• a lever arm (6) that transmits the power created by the wave energy converter (WEC) (5) to the cables (7),

• a reel (8) which changes the direction of the cable (7) transmitting power between the wave energy converter (WEC) (5) units and the main shaft (11) and which decreases friction,

• a pulley (9) which the cable (7) is connected to, which transmits the power obtained from each wave energy converter (WEC) (5) unit to the main shaft (11) during wave pass, which transmits power to the main shaft (11) during its forward motion, and which freely rotates to reverse direction,

• a freewheel (one way clutch) (10) which is the gear that allows the pulley (9) to rotate to one direction and that transmits the power to the main shaft (11) during reverse rotation, • a main shaft ( 1 1 ) on which as many pulleys (9) as the number of wave energy converters (WECs) (5) are installed and that transmits the created rotation motion to the generator (14) ,

• a counter balance weight (12) that rotates the pulley (9) to the reverse side for the next new wave pass,

• a reduction gear (13) that enables rotation rate adjustment to be performed by gear systems, and

• a generator ( 14) that converts the mechanical energy to electrical energy.

Power Take-Off System ( PTO) according to Claim 1 , characterized by comprising a plurality of wave energy converters (WEC) (5) that work by the "Objects Activated by Waves" principle gathered on a single main shaft (1 1 ) in a system.

Power Take-Off System ( PTO) according to Claim 1 , characterized by comprising a wave energy converter (WEC) (5) with buoyancy type system (5.1 ) and wheel blade type system (5.2) .

Power Take-Off System ( PTO) according to Claim 1 , wherein a lever arm (6) with at least one component is used to transmit the linear motion to the cable (7) as pulling in case a buoy type wave energy converter (WEC) (5) is used and to transmit the angular rotation motion to the cable as pulling in case a wheel blade type wave energy converter (WEC) (5) is used.

Power Take-Off System ( PTO) according to Claim 1 , characterized by comprising a cable (7) of which one end is connected to the wave energy converter (WEC) (5) unit and the other end is connected to the pulley (9) .

Power Take-Off System ( PTO) according to Claim 1 , characterized by comprising a system structure that transmits the power created in the plurality of wave energy converter (WEC) (5) units during wave pass to the generator ( 14) connected to the main shaft (1 1 ) and by comprising cables (7) made of polyester depending on the size.

Power Take-Off System ( PTO) according to Claim 1 , characterized by comprising a system structure that transmits the power created in the plurality of wave energy converter (WEC) (5) units during wave pass to the generator ( 14) connected to the main shaft ( 1 1 ) , and by comprising cables (7) made of steel depending on the size.

Power Take-Off System (PTO) according to Claim 1 , wherein the cables (7) which are the power transmission components are used as roller chains continuously wound around the wave energy converter (WEC) (5) vertical shaft (1 1 ) and the pulley (9) in the case that wheel blade rotating type wave energy converter (WEC) (5) is used instead of buoy type wave energy converter (WEC) (5) .

9. Power Take-Off System (PTO) according to Claim 1 , wherein the cables (7) which are the power transmission components are used as V-belts continuously wound around the wave energy converter (WEC) (5) vertical shaft and the pulley (9) in the case that wheel blade rotating type wave energy converter (WEC) (5) is used instead of buoy type wave energy converter (WEC) (5) .

1 0. Power Take-Off System ( PTO) according to Claim 1 , characterized by having a structure working without a lever arm (6) in case roller chains are used instead of cables (7) .

1 1 . Power Take-Off System ( PTO) according to Claim 1 , characterized by having a structure working without a lever arm (6) in case V-belts are used instead of cables (7) .

1 2. Power Take-Off System ( PTO) according to Claim 1 , characterized by comprising a reel (8) that changes the direction of the power transmitting cables (7) in the off-shore platform (1 ) depending on the positions of the wave energy converter (WEC) (5) units.

1 3. Power Take-Off System ( PTO) according to Claim 1 , characterized by comprising the pulley (9) that transmits the force carried by the power transmitting cables (7) to the main shaft (1 1 ) .

1 4. Power Take-Off System ( PTO) according to Qaim 1 , wherein the circular, single groove and 3-4 cm wide pulleys (9) are positioned side by side on the main shaft (1 1 ) and the number of pulleys (9) are the same as the number of wave energy converter (WEC) (5) units on the off-shore platform ( 1 ) inside the wave energy production system.

1 5. Power Take-Off System ( PTO) according to Claim 1 , wherein the connection of pulleys (9) to the main shaft (1 1 ) is not rigid, but has a freewheel ( 10) that can unidirectionally rotate between the pulley (9) and main shaft (1 1 ) .

1 6. Power Take-Off System (PTO) according to Claim 1 , wherein each pulley (9) has freewheels (10) that are located between the pulleys (9) and the main shaft (1 1 ) and that enable independent movement of the pulleys (9) even though they are positioned side by side on the single main shaft ( 1 1 ) depending on the wave force acting on the wave energy converter (WEC) (5) unit connected to it.

17. Power Take-Off System (PTO) according to Claim 1, characterized by comprising a main shaft (11) that is used horizontally.

18. Power Take-Off System (PTO) according to Claim 1, characterized by comprising a main shaft (11) that is used vertically.

19. Power Take-Off System (PTO) according to Claim 1, characterized by comprising a main shaft (11) that performs a partial rotation motion between ¼ and ½ revolutions depending on the buoy displacement of the wave energy converter (WEC) (5) units or depending on the rotation of the wheel blade and pulley (9) diameter during each wave pass.

20. Power Take-Off System (PTO) according to Claim 1, characterized by comprising a main shaft (11) that makes a regular rotation via the superposition of partial rotations having different phases and magnitudes applied by the plurality of wave energy converter (WEC) (5) units.

21. Power Take-Off System (PTO) according to Claim 1, characterized by comprising a counter balance weight (12) that prepares the pulley (9) ready for the next wave pass in case cables (7) are used as the power transmission components.