WO2007031800A1

WO2007031800A1 - Endless chain system producing electricity from currents

Info

Publication number: WO2007031800A1
Application number: PCT/GR2006/000045
Authority: WO
Inventors: Dimitrios Zikos
Original assignee: Dimitrios Zikos
Priority date: 2005-09-14
Filing date: 2006-09-12
Publication date: 2007-03-22

Abstract

The invention refers to an electromechanical system which converts the kinetic energy of the water or wind currents into electric energy using parachutes (5) . Closed loops (9) of cables incorporate co-axially fastened parachutes (5) are used as the main mechanism for capturing and converting the kinetic energy of the currents into electric energy. Each loop rotates a motive shaft (T) through a pulley (4) and the total torque is transmitted to the generator. The invention can use a great number of the above loops and functions reliably even into strong currents. It can float in a river or in the sea using floating elements (7) and an anchoring system (8) which controls the system's depth and inclination. The system uses sails (19) to direct the external current into the system increasing the impact velocity on the open parachutes and the produced power.

Description

ENDLESS CHAIN SYSTEM PRODUCING ELECTRICITY FROM CURRENTS

The invention refers to an electromechanical system which exploits the kinetic energy of the water or wind currents, converting it into electric energy using parachutes.

Until now, many inventions have been made for the exploitation of the Mnetic energy of the currents, which use parachutes connected axially on a cable. This cable forms a closed loop and spins around one or two pulleys which rotate a generator. These systems present many problems during their function.

Some of the patents which use the above loops are: the FR 2736101 A, the US 3,887,817 A, the FR 2756016

A, the SU 1295024 A, the US 2002/0056995 A and the US 4124182 A.

These systems are not designed for industrial scale energy production: they cannot guaranty long term reliable function under great loads, since the connection between the pulley and the cable is based only on friction, which will damage the parachutes and the cable.

Even the system of the FR 2736101 has the same friction problem: when the cable slides on the radiate ends of its motive pulley the parachutes will come in contact with them and they will be damaged.

The velocity of the currents in the sea or in the river or the wind currents vary between zero and some very high values affecting the axial load which the cable carries.

The motive pulley in each case accepts two forces from the loop: one from the return branch of the loop which carries the closed parachutes and one from the motive branch which carries the open parachutes.

When the velocity of the current is zero, the two forces are equal and the pulley does not rotate. As the velocity of the current increases, the force which comes from the return branch remains the same or relatively small, but the force from the motive branch with the open parachutes increases reaching high values. This difference between the two forces elongates a little the section of the cable which touches the perimeter of the pulley each time and for this reason it will start sliding on the pulley slowly. After a while the parachutes will come in contact with the pulleys and they will be damaged by the friction.

The two cables of the system of the patent FR 2756016 will be misaligned when the cables start sliding on the pulleys with different foot-pace, for the same reason.

The above systems are designed to use only a very small number of the above loops. For this reason their pulleys are designed as one part pulleys. Only the system of the US 2002/0056995 Al is designed to use many loops, but its shafts are fixed on the ground.

These systems are designed to use only one main shaft, which limits the size of the system.

Even when the system of the FR 2736101 functions into a steady current it produces varying power because of the formation of its pulleys: since the pulley's shape is not circular the distance between the center of the pulley and the cable which carries the stretching force of the open parachutes varies as the pulley rotates. As the radial pulleys on the same shaft have exactly parallel positions between each other, the above problem gets more intense.

All the above systems use the surface of the cable to come in. contact with the pulleys in order the stretching force of the open parachutes to be transported to the shaft of the motive pulley.

The above systems are designed just to float on the surface of the water.

All the above systems use the current as it simply passes around the parachutes. They all use a simple formation of the parachutes except FR 2736101 which uses an airbag and a mass on each parachute that create problems at the return branch, especially when it moves into the water.

The systems that use more than one loops on the motive shaft, use this shaft to transfer the produced torque to the generator, imposing the construction of this shaft in a very large dimensions. At the same time the generator accepts great torque in very slow rotation, imposing the choice of a high cost generator.

The bearing structure of some of the above systems is build rigid, having very high cost at large scale systems. The motive and auxiliary shafts of these systems cover all the width of the system having very high cost at large scale systems. The system producing electricity from currents, which incorporates cables which form closed loops, having coaxial parachutes fastened along the cable, where every loop rotates among two radial pulleys, fastened on a motive (2) and on an auxiliary shaft (3) respectively, which is characterized by the following: the system can work in water or wind currents, it incorporates one or more frames (1) as a bearing structure, each frame (1) can be constructed to be rigid or articulated having one or more pivot shafts a-a. These frames (1) can be arranged the one next to the other or the one under the other, each one incorporating at least one motive shaft (1), one auxiliary shaft (3) and it can incorporate one basic shaft (2a) and partial co-axial shafts (2b) collaborating to each other using pulleys (4) and a great number of the above loops (9), transferring the total roduced torque to one or more generators (14). Each loop (9) incorporates suitable fittings (11) fastened on the cable at both sides of each parachute and a chain of rigid rods connected to each other using spherical joints (11) can be used as a loop (9). The co-axial pulleys (4) are arranged having an angular displacement each one to its neighboring ones normalizing the tendency produced by the generator (14) and each radial pulley (4) incorporates suitable sockets (10) at the ends of its radiuses which engage with fittings (11) of the loops (9), using wheels (12,13). Floats (7) keep the system in the desired depth and inclination in the sea or in the river collaborating with control motors (4b) of the anchoring system (8), the floats (7) can be constructed having stable volume or electronically adjustable volume acting like a piston. The system can incorporate external sails (19) to divert the lateral current into the system which change their direction and change their inclination optimizing it into a current or a tide controlled by pistons (19a) and internal sails (20a,20b) which divert the lateral current into or away the parachutes (5,6) increasing the produced power, working at the same way at the two directions of a tide.

The system incorporates parachutes (5) which use specially designed fittings and formations and a computing control system optimizes the function of the system. Each radial pulley (4) can be assembled by two or more parts in order to get aligned on their common shaft in big systems and at the sockets (10) of the ends of each pulley (4) they can be fixed auxiliary (13) and basic wheels (12) on guiding fittings (1 Ia) which guide the spherical fittings (11) of the loop (9) at their engagement position in order to avoid the creation of friction and every radial pulley (4) on the motive shaft (2) can be fastened with a pulley or gear (4c), which transmits revolutions through proper chain (4e) to a pulley or a gear (4d) which has much lower diameter and this pulley or a gear (4d) is fastened on a basic shaft (2a) parallel to the motive shaft (T), which transmits revolutions to the generator (14) much faster than the motive shaft (2) could.

The shafts (2,3) of the system can be constituted from two or more parts, each motive (2) and each auxiliary (3) shaft can be replaced by partial co-axial shafts (2b) each one supporting one or more pulleys (4), when frames (1) are engaged to each other with an articulating engagement the co-axial shafts (2b) function like the articulations between neighboring frames (1) supporting at least one corresponding pulley (4) from each neighboring frame (1), and each one of these partial co-axial shafts (2b) when it functions like an articulation, it acts like motive and auxiliary shaft at the same time, transporting the torque produced from the one frame (1) to the other and finally to the one or more generators (14) of the system and the system can use a basic shaft (2a) to be connected to the generator (14) which collaborates with the motive shaft (2,2b) using proper pulleys (4c,4d).

The system can be supported to the ground or on the sea floor using one or more supports (8a) and when it floats in the sea or in a river it can use an anchoring system (8) incorporating weight anchors or a fixed point on the sea floor and a holding element (8b) like rope connects it with the system. The system can incorporate a pipe to cover the return branch of the parachutes (6).

On each frame (1) of the system a group of supports (Ia) is fastened and using suitable fittings (21) shafts (22) are fastened on these supports (Ia) and these shafts (22) hold the internal sails (20a,20b) and into these fittings (21) each shaft (22) can be rotated freely at the change of the direction of a tide at a restricted angle which is controlled by special fittings (21a) fastened on the ends of each shaft (22), where some of the internal sails (20a) direct the lateral current into the open parachutes (5) increasing the produced power and some others internal sails (20b) direct the current which passes close to the closed parachutes (6) away from them to reduce the friction between them. The internal sails (20a,20b) are fastened on the shafts (22) so as at the change of the direction of the current of the tide and using special fittings (21a) they change position so as the internal sails (20a) which were directing the lateral current into the open parachutes (5) to divert it away from the closed parachutes (6) and conversely tlie internal sails (20b) which were diverting the lateral current away from the closed parachutes (6) to direct it into the open parachutes (5). The internal sails (20a,20b) are fixed into elastic frames (20c) in order to be protected in a very fast current. Every parachute can use radiuses (5a), functioning like an umbrella, in order to facilitate it's opening procedure, it can use an internal fitting (23) having corrugations, it can use elastic fitting (24) along its perimeter, they can be used belts (a3) at both sides of the parachute having double function, it can be used level formation (5b) of the parachute, or it can be used rigid parachute which will remain always open, for example it can be plastic.

The system can incorporate two-dimensional or three-dimensional lattices or frames (Ia). The system is controlled by a computing control system which operates automatically through proper software or through orders that the system accepts wireless or through wire connection to a control center on the shore and incorporates sensors for the velocity of the current and of the waves, for example and it optimizes the function of the system, controlling the function of the motors (4b), the floats (7), the propellers (4a), the pistons (19a), the warning alarms, the generator (14) and the brakes of the generator (14).

The advantages of the proposed invention, in comparison to the above systems, are the following: first of all the engagement between the cable and the pulleys is not based on friction but on their mechanical engagement, without friction.

It uses specially designed loops which incorporate special fittings fastened on the cable between parachutes that come in contact with the specially designed ends of the radiuses of the pulleys. The ends of the radiuses of the pulleys incorporate wheels to come in contact with the cable and no friction appears during their mechanical engagement and disengagement.

This ensures the reliable long term function of the system without the danger of the relative slip of the cable on the pulley and the damage of the parachutes and the damage of the cable.

A chain of rigid rods wlύch connect to each other using spherical joints can also be used as a loop, instead of using a flexible cable, for increased strength during its stretching. The proposed system is designed for industrial energy production incorporating a very large number of pulleys and loops in every shaft, using specially designed frames to support the long shafts and two-component pulleys which can be assembled and disassembled very easily in any position of the shaft.

Each one of the frames of the system can be built as an articulated frame, for a serious reduction of the construction cost into very large scale systems. The proposed system can also use a very large number of shafts, as it can be developed in a great multilevel structure.

Each one of its motive and auxiliary shafts can be replaced from partial co-axial shafts each one supporting at least one pulley, for reduced construction cost These shafts can function as the articulations at frames connected through articulated arrangements between each other. The proposed system uses pulleys with radial formation but the deployment of the pulleys on the same shaft is designed to confront with the problem of the varying power which these pulleys generate and to minimize it.

The proposed system uses a specially designed floating system which controls electronically the depth and the inclination of the system in the water, using floats with varying volume.

The proposed system uses specially designed parachutes, ensuring high reliability at their opening every time they must open or remaining open both in the two directions of the current of a tide.

It also incorporates motors for the control of the anchoring system for better adjustment of the depth and the inclination of the system in the water, propellers for the adjustment of the system relatively to the current, computing control system which controls sensors, alarms, etc.

In every frame, a new basic shaft parallel to the motive shaft can be used, which receives all the torque from the pulleys of the motive shaft and transmits it to the generator in much more rotations per minute. So, this basic shaft can be constructed in much smaller dimensions than the motive one and permits the choice of a cheaper generator since it accepts more rotations per minute.

But the most serious advantage of the proposed system is the following: it uses external and internal sails which direct the external current into the system on the open parachutes increasing the impact velocity of the current falling on the parachutes and the produced power. It also incorporates sails that decrease the friction of the return branch in the current. They can function in steady or alternative direction current. An important consequence of using internal and external sails is that increasing the impact velocity of the current, they make even slow currents or tides economically exploitable. As we will see below, using sails higher attribution of the system is achieved with smaller volume of structure. Using all the above features, the system can produce electricity in a great scale with high reliability, low maintenance cost and very low and very competitive cost per kilowatt produced.

Figure 1 presents in a simplifying perspective view the system producing electricity from currents, using a single frame. Figure 2 presents the side view of the system working in a current and the function of a float in Fig 2a.

Figure 3 presents the system in a tide with opposite direction than in Figure 2.

Figure 4 presents the floor view of the frame of the Figure 2 without the sails and the frame 1 is articulated constructed using a pivot shaft a-a.

Figure 5 presents the perspective view of the system using a single frame, the supports Ia of the internal sails and the supporting and control system of the external sails 19.

Figure 6 presents the simplifying side view of the diversion of the side current from the external 19 and the internal sails 20a, 20b on the parachutes.

Figure 7 presents in a floor view the function of the internal sails 20a, 20b at the two directions of the current of a tide in the Figures 7a and 7b. Figure 8 presents the function of the internal sails 20a, 20b at the two directions of the current of a tide in the

Figures 8a and 8b as the cross sections of the Fig.7a and 7b.

Figure 9 presents the rotation of a pulley from the loop, Fig. 9a, the fitting 23 in the parachutes, Fig. 9b, the fitting 24 at the perimeter of the parachute, Fig. 9c and the formation of the parachute like an umbrella, Fig. 9d.

Figure 10 presents the perspective view of a parachute having level formation 5b and the way it functions during the several phases of its motion.

Figure 11 presents a parachute designed to remain open at both the two directions of the current of a tide using the belts a3 and the function of the sails 20a. Figure 12 presents the simpUfying side view of the system using a single frame functioning in shallow waters like a river, which incorporates supports in the river floor, the return branch is out of the water, double action parachutes are used and the generator is located above the level of the water.

Figure 13 presents in a simpUfying perspective view the energy production system from water currents, using three co-planar frames which collaborate to each other. Figure 14 presents the formation of a pulley which consists of two parts.

Figure 15 presents the relative deployment of the pulleys on the same shaft.

Figure 16 presents the formation of the end of a radius of a pulley incorporating wheels 12, 13 and its engagement with a fitting fastened on the loop.

Figure 17 presents the bushing which festens a shaft on the frame 1. Figure 18 presents the pulley 4, the pulley 4c, the pulley 4d and the belt 4e.

Figure 19 presents the floor view of a series of articulated frames 1, the pulleys 4c and 4d, the basic shaft 2a and the partial co-axial shafts 2b holding collaborating pulleys from successive frames F,G,H, ... .

Figure 20 presents in a simpUfying perspective view the energy production system from water currents, using three parallel levels each one incorporating three co-planar frames which collaborate to each other. Figure 21 presents the system exploiting the wind currents using many frames on a pylon 8a incorporating sails 19.

One way for applying the invention is presented with reference to the above Figures. As we can see in Figures 1,4, at least one shaft 2 and at least one shaft 3 are fastened on the frame 1, which is used as the bearing structure. Pulleys 4 are fastened on these shafts having radial shape, Figure 9. The ends of the radiuses 10 of each pulley 4 come in contact with a closed loop which is formed by the cable (or belt) 9, Figure 2,9a Each loop is being stretched between a pulley 4 on the shaft 2 and a collateral pulley 4 on the shaft 3. The shaft 2 is characterized as motive because it transmits torque to the generator 14, Figure 4, while the shaft 3 is characterized as auxiliary. Parachutes 5, having spherical or other formation, are fastened in concrete positions on the cable 9 and fittings 11 are fastened between them, Figures 2,9.

Parachutes 5 are drifted by the current pulling each cable 9 to the direction of the current. The ends of the pulleys 4 have specially shaped sockets 10 to engage with the fittings 11, Figure 16: as the pulley rotates and a free end of the pulley approaches the fitting 11 of the cable 9, the cable is guided from the guiding fittings 11a to the center of the socket 10 using the auxiliary wheels 13. When the fitting 11 abuts on the socket 10, it is guided through the wheels 12 to take its final position among them until it disengages from the pulley, during its rotation.

Using the rolling of these wheels the cable 9 engages reliably with each socket 10 of the pulley and no friction appears between the fittings 11, the cable 9 and the pulley 4 during their engagement and disengagement. Using this mechanism the stretching forces of the open parachutes 5 are transmitted through the cables 9 and converted into torque on the motive shaft 2, Figure 1.

The system can also use a loop of rigid rods which connect to each other using joints 11, instead of using a cable 9 and fittings 11.

Pulleys 4 have radial shape with 3, 4, 5 or more radiuses and during their rotation they do not abut against the loop and the parachutes using the above mechanism.

The pulleys 4 which are fixed on the same shaft are assembled each one having an angular offset to it's neighboring one, Figure 15, normalizing the fluctuation of the torque which they transmit to the generator and normalizing the tendency which the generator 14 produces. As we mentioned above, the fluctuation of the torque occurs since the pulley's shape is not circular and the distance between the center of the pulley and the cable which carries the stretching force of the open parachutes varies as the pulley 4 rotates.

In the return branch of the loop 9 the parachutes shrink and close 6, Figure 2, 9a. The return branch of each loop carrying the closed parachutes 6 can move in a protective pipe, in order to reduce it's friction with the current when it moves into it at a fully submerged system into the sea. In order to facilitate the assembly of the pulleys on each shaft and in order to be aligned to each other on the common shaft in great scale systems the pulleys can be constituted from 2 parts 4a, 4b, which are connected using screws, Figure 14.

The shafts of the system can be constituted from one or more parts, which are connected to each other using couplings, like flanges.

The structure of the frame 1 ensures the holding in place of the shafts 2,3 parallel and co-planar to each other even under the hardest strains from the external current Simple pipes or two-dimensional or three-dimensional frames or lattices can be used as the separate elements Ia, which form the frame 1, Figure 5, which would ensure the desired sturdiness of the structure. Figure 4 presents the connection of the shafts 2,3 to the frame 1. These connections are located in selected points of the shafts using bushings 16, Figure 17.

The generator 14 is connected to the motive shaft 2 using a disk 18 and a toothed belt, Figure 4.

The above description presents the development of the system in the simpler possible structure using one motive and one auxiliary shaft, hi order to achieve scale economies, the above system can be used 2, 3 or more times, Figure 13, in a large structure in which separate frames 1, with names A, B, C, are assembled in a chain arrangement, the one beside the other.

Examining the Figure 13, we can see the auxiliary shaft 2 of the frame C, named as 2C, collaborating with the motive shaft 1C. The shaft 1C which is also an auxiliary shaft to the frame B, that is to say 2B, collaborates with the shaft IB. With this way the torque which the frame C produces is transmitted to the motive shaft IB, which transports the whole torque, which the frame C and the frame B produce, to the shaft IA and to the generator 14, using the same mechanism.

The structure of Figure 13 can be considered as co-planar arrangement of the frames 1 of the Figure 1.

The system can also be developed in a more complex structure which is presented in Figure 20, where the above co-planar structure of Figure 13 is displayed in aperspective way, developed in three levels El, E2, E3, the one under the other, for example. The transmission of torque from one level to the next one is succeeded using suitable torque transmission system.

The usage of the three frames A, B, C and the three levels was presented in order to simplify and facilitate the presentation of the system. The structure can be constructed using any number of frames and levels.

The system can use one or more generators 14, depending on its formation. These generators can be pneumatic, hydraulic, electric, etc.

The system can float near the surface or near the sea floor, in horizontal or in inclined position, Figure 2,1.

The system can be supported by one pylon 8a, Figure 21, or by a group of stable supports fastened on the ground or on the sea floor 8a, Figure 12, or it can float using floats 7 and an anchoring system 8.

The anchoring system can incorporate one or more stable points 8 on the ground or on the sea floor, Figures

1,13, or one or more weight anchors 8c, using cement cubes, for example, Figure 2,4. Weight anchors will be used for installing the system into deep waters, without the need of the expensive installation works on the sea floor. The motors 4b which control the anchoring system, Figure 2,4, co-operate with the floats 7 for the adjustment of the height and the inclination of the system into the current, using holding elements 8b, Figure 1, like ropes.

The volume of each float 7 can be stable, Figure 1,13 or adjustable, Fig.2a. The figure-detail Fig. 2a in Figure

2 presents the function of a float 7 with adjustable volume which functions like a piston: at the position (I) the float 7 is presented having half of it's volume empty, at the position (H) the float 7 is presented having all of it's volume empty and at the position (IH) the float 7 is presented having minimized it's empty volume.

The fluctuation of the available volume of the float 7 is achieved transferring the piston 7b into the pipe 7a using electric, electromagnetic, pneumatic or other mechanism and is controlled by the computing control system of the system. When the pipe 7a is empty from the one side of the piston, the external water creates buoyancy force to the float 7. On the other side of the piston, the pipe is filled with water which adjusts the size of the buoyancy force.

These forces are transmitted to the frame 1 of the system.

The above assembly ensures the possibility of electronic adjustment of the buoyancy force that the system accepts, adjusting thus electronically the depth and the operating inclination of the system into the current every moment, in co-operation with the anchoring system.

The system can also incorporate sails for the reinforcement of the current which crashes into each open parachute: they direct the current passing beside the system into it, in order to increase the impact velocity on the open parachutes and the produced power of the generator 14. It is known from the theory of Fluid Dynamics that the force which each parachute produces is proportional to the cube of the velocity of the current that accepts. Thus, the produced power of the system can be increased, increasing the impact velocity of the current on the open parachutes and decreasing it in the sector of return. TMs is achieved using external sails 19 and internal sails 20a, 20b, Figures 2,6, which are located in suitable positions and in suitable stable supports on the frames 1. These sails have the following three operations: a. The external sails 19 divert the current which passes beside each frame 1 and they direct it in the frame 1, on the internal sails and in the open parachutes. b. Hie internal sails 20a divert the current that passes beside the open parachutes 5 and they direct it on the open parachutes increasing the velocity of the current which these parachutes already accept, Figure 6. c. The internal sails 20b divert away the current that passes beside the closed parachutes of the return branch, decreasing the velocity of the current that comes in contact with them and the friction developed between the current and the closed parachutes, Figure 6.

The formation of the sails optimizes the operation of the energy production system from currents. An important consequence of using internal and external sails is that increasing the impact velocity of the current, they make even slow currents or tides economically exploitable.

In a line of successive coaxial parachutes which move into a current, the presence of the first parachute decreases the velocity of the current that the next parachute accepts, decreasing thus the produced power.

In order to avoid this decrease, the distance between the two successive parachutes must exceed a specific size which depends on the velocity of the current. Using the internal and external sails, the distance between two successive parachutes can be shortened: the decreased velocity of the current from the front parachute to the next one is reinforced by the lateral currents that they accept from the external and internal sails.

With this way higher attribution of the system is achieved with smaller volume of structure.

The sails are presented in Figures 2,3 and their function is analyzed in Figures 6,7,8. Sails 19 function as the internal sails do: they divert the utilized current that passes beside the system, into the system. This current falls on the internal sails whόre it gets reinforced even more and finally it falls on the open parachutes with the maximum possible impact velocity, increasing the produced energy, Figure 6.

In Figures 2,3, we can also see the function of the sails 19 when the direction of the current changes, as it happens in a tide. During the change of the direction of the current, the external sails 19 change inclination being controlled by the pistons 19a. Pistons 19a not only guide the sails 19 to follow the change of the current's direction, but each moment they guide the sails 19 to take the optimum inclination as the velocity of the current changes, being controlled by the computing control system of the system.

In Figure 6 we can see the shaft 22, which supports constantly two sails 20a and 20b in vertical position. The arrangement of the shafts 22 supporting the sails 20a and 20b is located in many positions at both sides of each loop, Figures 7,2. In these Figures only one loop of parachutes is demonstrated for simplicity purposes. Each shaft 22 is fastened on the beams-supports Ia using the fittings 21. The beams Ia are parallel to the loops of the parachutes and they are fixed on each frame 1 of the system, as we see in Figure 5, where one single frame 1 is presented using the beams Ia and the external sails 19. Sails can be used even when the system incorporates a great number of frames 1.

As we can see in Figures 6, the shaft 22 can drift freely by the current into the fittings 21 at a restricted angle. This angle depends on the formation of the fittings 21a, which are fixed on the ends of the shaft 22. The fittings 21a in combination with the sails 20a and 20b which are fastened on the shaft 22, succeed the following operation as we can see at the floor plan in the Figure 7a and at the cross section in Figure 8a: when the beside parachutes are open, the sails 20a direct the current that passes beside the open parachutes 5 on the series of the open parachutes. WiUi this operation, the impact velocity of the current on each open parachutes, thus the produced power of the system, increases.

At the same time, the sails 20b which stand beside the closed parachutes 6 are positioned in order to divert away the current that passes close beside the closed parachutes. The result is the reduction of the velocity of the current which passes close beside the closed parachutes and the reduction of the friction at the return branch of the system.

When the direction of the current changes, as happens in tides, sails 20a and 20b get pushed by the water and rotate the shaft 21 inside the fittings 21, as much as the fittings 21a permit them to rotate. Ih this new direction of the current, the open parachutes close and the closed parachutes open. Then the sails 20a and 20b function in a reverse way than they did before, as we can see in Figures 7b, 8b: the sails 20a divert the current away of the closed parachutes (which they were open before) and the sails 20b divert the water on the open parachutes (which they were closed before). The internal sails (20a,20b) are fixed into elastic frames (20c) hi order to be protected in a very fast current In Figures 9,10,11, a series of alternative improvements on the design of the parachute are displayed, in order the opening procedure becomes more reliable.

In Figures 9a,9b, the fitting 23 having corrugations is applied into a parachute in order to facilitate the entrance of the water or the wind in the closed parachute and open it easier. In Figure 9c the fitting 24 which is made of spumescent or similar elastic material is applied on the perimeter of the parachute, making it's opening easier when it is needed. In Figure 9d the parachute is formed like an umbrella using radiuses 5a.

Figure 10 presents a parachute with a level formation 5b and details from its movement across the loop of the parachutes, moving in horizontal or inclined level with an inclination α°: it incorporates a mass 12b which is connected to a point s of the cable using a rope, in order to be guided at the return branch, as we can see in this figure.

The usage of a level formation of a parachute 5b minimizes the friction in the return branch when it moves into the current, but it has also the disadvantage that this formation has less current resistance when it stands against the current direction producing less power, comparing to the classic form of a parachute 5. In Figure 11 we can see another formation of a parachute which remains open during both the opposite directions of the current of a tide incorporating belts a3 at both the sides of the parachute 5. Figure 21 presents the system exploiting the wind currents or water currents with varying direction, using many frames on a pylon 8a incorporating sails. A pylon 8a supports the system allowing it to rotate to different directions following the direction of the current, using Hie rings 8b. The change of the direction of the system can be controlled by wings or electric motor. The sails 19 are presented mainly at the floor view of the system keeping a side position relatively to the system. The system is developed in many parallel frames 1, which transmit torque to one generator 14 using a torque transmitting system like belts 8s.

The system uses also a series of beacons and alarms that make the system optically and electronically recognizable by the radars of the ships that move in the territory. The system uses also a series of propellers 4a, Figure 2,4, which control the position of the system relatively to the direction of the current, being controlled by the computing control system of the system. The generator 14 uses also brakes which get activated in cases of very slow and very fast currents, which ensure that the system operates in predefined limits of the current velocity according to the specifications of its manufacturer. In order to reduce the construction cost of the system, the frame 1, which was considered to be rigid until now, can be constructed to be articulated, especially in systems with very large size. In Figure 4 we can see the frame 1 incorporating a pivot shaft a-a. It can also use more than one pivot shafts a-a. The transmitting of torque from the motive shaft 2 directly to the generator 14, imposes the motive shaft 2 to be constructed in very large dimensions, since it transmits very high torque having low revolutions. Since the motive shaft 2 operates in low revolutions, the generator must operate in low revolutions too, which imposes the choice of a very expensive generator 14.

In order to confront this problem, an additional shaft 2a has to be used, parallel to the motive shaft 2. The motive shaft 2, as we will see below, can be replaced by partial co-axial shafts 2b, Figures 18,19. Each pulley 4 of the motive shaft 2 or 2b can incorporate a pulley or gear 4c fastened on it, each one collaborating with a pulley or gear 4d of much lower diameter on the basic shaft 2a, using the chain 4e.

So, torque is transmitted from the shaft 2 or the shafts 2b to the basic shaft 2a, Figure 19. Because of the analogy of the sizes of their pulleys the basic shaft 2a rotates in much more revolutions than the motive shaft 2 or 2b do so is has to be constructed in much lower dimensions than the motive shaft 2 or 2b transmitting to the generator much more revolutions than the motive shaft 2 or 2b could, allowing the choice of a low cost generator 14.

In order to reduce the cost of the system, motive 2 and auxiliary 3 shaft which were covering all the width of a frame 1, they can be replaced by partial co-axial shafts 2b each one holding one or more pulleys 4 in the case of a single frame 1, as we mentioned above. In the case of the chain arrangement of a series of frames 1, as the successive frames F,G,H, in the Figure 19, the shaft 2b can hold one or more corresponding pulleys 4 of two neighboring frames 1, acting additionally as a connecting articulation of the two neighboring frames 1.

Each series of these partial co-axial shafts 2b functions as motive shaft for the one frame and at the same time as auxiliary shaft for the other articulated frame, transmitting the torque produced from the one frame to the other and from all the frames 1 to one or more generators 14.

The system incorporates a computing control system which uses data from sensors relatively to the velocity of the current, the waves, the wind, etc, and performs automatically using proper software. It can also be controlled by a wire or wireless communication system from a control center on the shore, optimizing the performance of the system. It controls the function of: the anchors 8, the floats 7, the propellers 4a, the pistons 19a, the brakes of the system, the warning alarms and the generator 14. The sails 19 and their control system can also be used over, beside and below of each frame 1.

We must mention here that the present description of the invention refers to certain indicative examples of the development of the system.

Thus, any change or modification regarding the formation, the shape, the dimensions, the used materials and fittings for manufacturing and assembling the system, is considered to be contained in the objectives and aspirations of the present description.

Claims

1. System producing electricity from cuixents, which incorporates cables which form closed loops, having coaxial parachutes fastened along the cable, where every loop rotates among two radial pulleys, fastened on a motive (2) and on an auxiliary shaft (3) respectively, which is characterized by: the system can work in water or wind currents, it incorporates one or more frames (1) as a bearing structure, each frame (1) can be constructed to be rigid or articulated having one or more pivot shafts (a-a) and these frames (1) can be arranged the one next to the other or the one under the other, each one incorporating at least one motive shaft (2), one auxiliary shaft (3) or partial co-axial shafts (2b) instead of the motive (2) and the auxiliary (3) shafts and it can incorporate one basic shaft (2a), collaborating to each other using pulleys (4) and a great number of the above loops (9), transferring the total produced torque to one or more generators (14), each loop (9) incorporates suitable fittings (11), having spherical or other formation, fastened on the cable (9) at both sides of each parachute and a chain of rigid rods connected to each other using joints (11) can be used as a loop (9), the co-axial pulleys (4) are arranged having an angular displacement each one to its neighboring ones normalizing the tendency produced by the generator (14) and each radial pulley (4) incorporate suitable sockets (10) at the ends of its radiuses, which engage with the fittings (11) of the loops (9), which can incorporate wheels (12,13), floats (7) keep the system in the desired depth and inclination in the sea or in the river collaborating with control motors (4b) of the anchoring system (8), the floats (7) can be constructed having stable volume or electronically adjustable volume acting like a piston, the system can incorporate external sails (19) to divert the lateral current into the system, pistons (19a) change and optimize the direction and the inclination of the external sails (19) into a current or a tide and internal sails (20a,20b) which divert the lateral current into or away the parachutes (5,6), increasing the produced power, working at the same way at the two directions of a tide, the system incorporates parachutes (5) which use specially designed fittings (23,24) and formations (5a,5b) and a computing control system optimizes the function of the system.

2. System producing electricity from currents, according to claim 1, which is characterized by: each radial pulley (4) can be assembled by two or more parts in order to get aligned on their common shaft in big systems and on the sockets (10) of the ends of each pulley (4) they can be fixed auxiliary wheels (13) on guiding fittings (Ha) and basic wheels (12) which guide the fittings (11) of the loop (9) at their engagement position in order to avoid the creation of friction.

3 System producing electricity from currents, according to claims 1,2, which is characterized by: the shafts (2,3) of the system can be constituted from two or more parts, each motive (2) and each auxiliary (3) shaft can be replaced by partial co-axial shafts (2b) each one supporting one or more pulleys (4), when frames (1) are engaged to each other with an articulating engagement the co-axial shafts (2b) function like the articulations between the neighboring frames (1), each one supporting at least one corresponding pulley (4) from each neighboring frame (1) and each one of these partial co-axial shafts (2b) when it functions like an articulation, it acts like motive and auxiliary shaft at the same time, transporting the torque produced from the one frame (1) to the other and finally to the one or more generators (14) of the system.

4. System producing electricity from currents, according to claims 1,2,3, which is characterized by: the system can be supported to the ground or on the sea floor using one or more supports (8a) and when it floats in the sea or in a river it can use an anchoring system (8) incorporating weight anchors or a fixed point on the sea floor and a holding element (8b) like rope connects it to the system.

5. System producing electricity from currents, according to claims 1,2,3,4, which is characterized by: the system can incorporate a pipe to cover the return branch of the parachutes (6).

6. System producing electricity from currents, according to claims 1,2,3,4,5, which is characterized by: on each frame (1) of the system a group of supports (Ia) is fastened and using suitable fittings (21) shafts (22) are fastened on these supports (Ia) and these shafts (22) hold the internal sails (20a,20b) and into these fittings (21) each shaft (22) can be rotated freely at the change of the direction of a tide at a restricted angle which is controlled by special fittings (2Ia) fastened on the ends of each shaft (22), where some of the internal sails (20a) direct the lateral current into the open parachutes (5) increasing the produced power and some others internal sails (20b) direct the current which passes close to the closed parachutes (6) away from them to reduce the friction between them.

7. System producing electricity from currents, according to claims 1,2,3,4,5,6, which is characterized by: the internal sails (20a,20b) are fastened on the shafts (22) so as at the change of the direction of the current of the tide and using special fittings (21a) they change position so as the internal sails (20a) which were directing the lateral current into the open parachutes (5) to divert it away from the closed parachutes (6) and conversely the

5 internal sails (20b) which were diverting the lateral current away from the closed parachutes (6) to direct it into the open parachutes (5).

8. System producing electricity from currents, according to claims 1,2,3,4,5,6,7, which is characterized by: the internal sails (20a,20b) are fixed into elastic frames (20c) in order to be protected.

10

9. System producing electricity from currents, according to claims 1,2,3,4,5,6,7,8, which is characterized by: every ^"parachute can use radiuses (5a), functioning like an umbrella, in order to facilitate it's opening procedure, it can use an internal fitting (23) having corrugations, it can use elastic fitting (24) along its perimeter, they can be used belts (a3) at both sides of the parachute having double function or it can be used

15 level formation (5b) of the parachute.

10. System producing electricity from currents, according to claims 1,2,3,4,5,6,7,8,9, which is characterized by: the system can incorporate two-dimensional or three-dimensional lattices or frames (Ia).

20 11. System producing electricity from currents, according to claims 1,2,3,4,5,6,7,8,9,10, which is characterized by: the system is controlled by a computing control system which operates automatically through proper software or through orders that the system accepts wireless or through wire connection to a control center on the shore and incorporates sensors for the velocity of the current and of the waves, for example and it optimizes the function of the system, controlling the function of the motors (4b), the floats (7), the propellers

25 (4a), the pistons (19a), the warning alarms, the generator (14) and the brakes of the generator (14).

12. System producing electricity from currents, according to claims 1,2,3,4,5,6,7,8,9,10,11, which is characterized by: every radial pulley (4) on the motive shaft (2) can be fastened to a pulley or gear (4c), which transmits revolutions through proper chain (4e) to a pulley or a gear (4d) which has much lower diameter and 30 this pulley or a gear (4d) is fastened on a basic shaft (2a) parallel to the motive shaft (2), which transmits revolutions to the generator (14) much faster than the motive shaft (2) could.

35

40

45

50

55