Water current power generation transmission device and water current power generation device

Abstract

To provide a transmission device for a hydraulic power generation which can prevent a rotating body from flowing away while enabling the rotating body to rotate stably even in an environment where power of water flow is intense.SOLUTION: A hydraulic power generator 1 changes water flow energy of water flow into rotational energy to generate electric power and includes: a rotating body 10; a shaft 5 which transmits rotation of the rotating body 10 to a power generator; a support pillar 2 to which the shaft 5 is rotatably attached; and a support member 3 which is fixed at one end to the support pillar 2 and supports the rotating body 10 at the other part. The support member 3 supports the rotating body 10 while maintaining rotation of the rotating body 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a water current power generating transmission and a water current power generating device. [Background technology]

[0002] It is said that ocean currents contain several hundred TWh of energy per year around the world. Because ocean currents are more stable than the fluctuations of solar and wind power, power generation using ocean currents is attracting attention as a stable power generation method. Furthermore, because ocean current power generation does not emit carbon dioxide (CO2), it is also attracting attention as a natural energy source with an extremely small environmental impact. BACKGROUND ART Conventionally, there has been a technology that uses the water current of the sea or a river to rotate a rotor such as a propeller, thereby converting the kinetic energy of the water current into electrical energy to generate electricity.

[0003] Patent Document 1 describes a technology for generating electricity using tidal currents, in which a hollow support rod is installed at a fixed position underwater, and screw blades are installed on the support rod that rotate in response to the upper currents in the ocean and screw blades that rotate in response to the lower currents in the ocean, and the rotational force of the screw blades, which are rotated by both the upper and lower currents, drives a generator in a station installed on the sea surface to generate electricity.

[0004] Patent Document 2 describes a technology for generating electricity using water currents, in which piles are driven into the bottom of a river and a floating body equipped with power generation equipment having a rotating body (screw blade) that rotates in response to the natural flow of water is attached to the piles, allowing it to rise and fall.

[0005] Patent Document 3 describes a technology in which multiple underwater rotors are arranged in a vertical row on a vertical member fixed to the seabed, and the energy generated by ocean currents to rotate the underwater rotors is transmitted to a generator on the sea.The technology describes a technology in which the underwater rotor has a body section that is streamlined from the front end to the rear end, and rotates in response to the water current, transmitting the rotational energy of the underwater rotor to a generator on the sea. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-257023 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-169564 [Patent Document 3] Japanese Patent Application Laid-Open No. 2009-121241 Summary of the Invention [Problem to be solved by the invention]

[0007] However, because the water currents in oceans and rivers are fast, the rotors in the water are constantly pushed downstream by the force of the current, and the rotors are subject to rocking motion due to turbulence, etc. This can cause the connection between the rotor and the power generating device to be damaged or destroyed, resulting in the rotor becoming detached from the power generating device and being washed away. In particular, because ships operate in rivers and oceans, it is necessary to prevent accidents in which a rotor that is washed away collides with a ship. Patent Documents 1 to 3 do not mention or suggest measures to prevent the rotor from becoming detached from the power generating device and being washed away due to water currents. When generating electricity by rotating a rotor with water currents, there is a need to develop technology that firmly supports the rotor while maintaining its rotation, even in environments with strong water currents, to prevent the rotor from being washed away.

[0008] The present invention has been made in consideration of such circumstances, and aims to prevent the rotor from being washed away while allowing it to rotate stably even in an environment with strong water currents. [Means for solving the problem]

[0009] The invention described in claim 1 is a generator comprising a rotor that rotates due to a water flow, a shaft that transmits the rotation of the rotor to a generator, a support to which the shaft is rotatably attached, and a support member that is fixed at one end to the support and rotatably supports the rotor at the other end. The support member is a cylindrical body extending in the direction of the rotation axis of the rotor, and a convex portion protruding radially outward from the support member faces a concave portion inside the rotor, thereby rotatably supporting the rotor. Water current power generation Power transmissionIt is a device.

[0010] The invention described in claim 2 is A water current power generation transmission device comprising: a rotor that rotates due to the water current; a shaft that transmits the rotation of the rotor to a generator; a support post to which the shaft is rotatably attached; and a support member that is fixed at one end to the support post and rotatably supports the rotor at the other end, wherein the support member is a cylindrical body that extends in the direction of the rotation axis of the rotor, and the rotor is rotatably supported by a recess formed radially inward of the support member and a protrusion protruding from the inside of the rotor. is.

[0014] Claim 3 The invention described in claim 1 or Claim 2. This is a water current power generation device equipped with multiple water current power generation transmission devices. [Effects of the Invention]

[0015] According to the present invention, the support member fixed to the support pole can support the rotor while maintaining its rotation, thereby preventing the rotor from coming off the power generation device and being carried away by the water current, allowing for stable power generation. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram showing a water current power generation device according to a first embodiment. [Figure 2] FIG. 10 is a diagram showing a water current power generation device according to a second embodiment. [Figure 3] FIG. 10 is a diagram showing a water current power generation device according to a third embodiment. [Figure 4] FIG. 4 is a perspective view of the water current power generation device of FIG. 3. [Figure 5] FIG. 10 is a diagram showing a water current power generation device according to a fourth embodiment. [Figure 6] FIG. 10 is a diagram showing a water current power generation device according to a fifth embodiment. [Figure 7] FIG. 10 is a diagram showing a water current power generation device according to a sixth embodiment. [Figure 8] This is a diagram of a water current power generation device with four rotating bodies arranged vertically. [Figure 9] FIG. 1 is a diagram of a water current power generation device with multiple support columns. DETAILED DESCRIPTION OF THE INVENTION

[0017] The power generating device according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments.

[0018] (First embodiment) Figure 1 is a diagram showing a water current power generation device according to a first embodiment. As shown in Figure 1, the water current power generation device 1 of this embodiment comprises a rotor 10, a shaft 5 that transmits the rotation of the rotor 10 to a generator 20, a support 2 to which the shaft 5 is rotatably attached, and a support member 3 that has one end fixed to the support 2 and the other end supporting the rotor.

[0019] The support 2 may be fixed to the bottom of the water so that it does not move due to the influence of water currents, or may extend downward from a floating facility that is connected by a rope or the like to an anchor fixed to the bottom of the water. The inside of the support 2 is preferably hollow so that the generator 20 and the like can be stored inside. The support 2 is provided with a hole of a size that allows the shaft 5 to be inserted, and the shaft 5 can rotate, but an appropriate waterproofing mechanism is provided to prevent water from entering through the hole from outside the support 2.

[0020] In this specification, "water current" refers to the flow of water or seawater, and includes not only the direction of laminar flow in which the flow lines are aligned in layers, but also turbulent flow in which the flow lines are disturbed. "Direction of water current" refers to the main direction of the entire flow, whether it is laminar flow or turbulent flow. Unless otherwise specified, "upward" refers to the direction from the bottom of the water to the surface of the water, and "downward" refers to the direction from the surface of the water to the bottom of the water. Unless otherwise specified, "forward" refers to the upstream direction of the water current, and "backward" refers to the downstream direction of the water current.

[0021] In this specification, a "rotating body" refers to an object or device that receives the force of a water flow and converts the water flow energy into rotational energy. Therefore, the rotating body may have blades that can receive the water flow and convert it into rotation. The blades may have a shape that draws a spiral obliquely in the longitudinal direction.

[0022] The rotor 10 is a structure capable of converting the energy of the water flow into rotational energy of the rotor 10. For example, in the example shown in FIG. 1 , the rotor 10 is installed downstream of the support 2, and multiple blades 11 attached to the body of the rotor 10 receive the water flow and rotate the rotor 10. The blades 11 are preferably shaped to allow the rotor to easily rotate when receiving the water flow, and may be formed in a spiral shape surrounding the body of the rotor. The rotor 10 may be installed upstream of the support 2, but because doing so may cause the rotor 10 to oscillate violently, in the first embodiment, the rotor 10 is installed behind the support 2, i.e., downstream. The rotor of the first embodiment has a cylindrical structure that is open at the front and closed at the rear, and a shaft 5 is fixed to the bottom of the rear.

[0023] The length of the rotor 10 in the direction of the rotation axis may be made larger than the diameter in the radial direction (at the center of the body), so that it rotates with the water current while extending downstream, making it less susceptible to vertical oscillation. In the first embodiment, the rotor 10 has a radial diameter of approximately 10 m and a length in the direction of the rotation axis of approximately 20 m. The rotor 10 is made of resins such as fiber-reinforced plastic (FRP) and carbon-fiber-reinforced plastic (CFRP), or metals. If the rotor is made of a titanium alloy, it will not rust even in water and can be used semi-permanently.

[0024] The shaft 5 is fixed to the rotor 10 and rotates integrally with the rotor 10, thereby transmitting the rotation of the rotor 10 to the generator 20. The shaft 5 and the rotor 10 are integral so that they rotate together. Alternatively, the shaft 5 may be connected to the rotor via a fixed plate or the like to which the shaft 5 is fixed. As shown in FIG. 1, the shaft 5 is connected to the generator 20 disposed inside the support 2, and thus can transmit the rotation of the rotor 10 to the generator 20. The generator 20 converts the rotational energy transmitted by the shaft 5 into electrical energy. Note that the term "shaft that transmits the rotation of the rotor to the generator" includes not only a shaft directly connected to the generator, but also a shaft that transmits rotation to the generator via gears or the like.

[0025] The support member 3 is a cylindrical member extending parallel to the rotation axis of the shaft 5, with the shaft 5 passing through the inside of the support member 3. One end of the support member 3 is fixed to the support pole 2, and the rotor 10 encases part of the outer periphery of the cylindrical member of the support member 3. A convex portion 4 that protrudes radially outward from the outer wall surface of the cylindrical shape of the support member 3 is formed on the outer periphery of the cylinder. The convex portion 4 is positioned so as to face a recessed portion 7 formed in a groove shape on the inner wall surface of the rotor 10. As a result, even when the water current is strong, the rotor 10 is supported by the convex portion 4 of the support member 3 fixed to the support pole 2, and the rotor 10 will not come off the water current power generation device 1 and be swept downstream by the water current, and will be able to maintain its rotational motion. Furthermore, although not shown, the support member 3 may have an extendable structure while being fixed to the support pole 2. If the support member 3 has an extendable structure, the distance of the rotor 10 from the support pole 2 can be adjusted, and therefore the rotor 10 can be positioned at an optimal position where the resistance of the support pole 2 to the water flow is minimized.

[0026] In this specification, "facing" refers to a state in which opposing components fit together, but the opposing components do not necessarily need to be in contact with each other, and also includes a state in which the opposing components are spaced apart but still restrict specific movements of the opposing components. For example, "facing" includes a structure in which opposing components support each other via oil, bearings, or a combination thereof, even if the convex and concave portions are not in direct contact with each other.

[0027] A plurality of bearings 8a, 8b may be arranged on the outer periphery of the cylinder of the support member on the front and rear sides of the protrusion 4. The rear bearing 8b needs to be strong enough to withstand the force of the water current trying to wash away the rotor 10. The presence of the bearing 8 reduces resistance to the rotational motion of the rotor 10, allowing it to rotate at a higher speed. Furthermore, oil can be filled into the space formed by the recess 7 and the protrusion 4 of the rotor 10, allowing the rotor 10 to rotate smoothly and stably. When filling the recess 7 with oil, a known technique can be used to create a sealed structure to prevent oil leakage.

[0028] There are no particular restrictions on the size or material of the convex portions 4 and concave portions 7, as long as they are strong enough to withstand the force of the water currents that the rotor 10 receives and maintain stable rotation. Furthermore, if the depth of the concave portions 7 is greater than the height of the convex portions 4, the space between the convex portions 4 and the concave portions 7 can be filled with oil or bearings, allowing for smooth rotation.

[0029] The bearing 8a on the front side of the protrusion 4 and the bearing 8b on the rear side of the protrusion 4 may or may not be the same size. The rear bearing 8b needs to be strong enough to withstand the force of the water current trying to sweep away the rotor 10, while also needing to maintain rotation, so it may be a bearing with a larger diameter than the front bearing 8a. Making the rear bearing 8b larger than the front bearing 8a makes it possible to provide stronger support against the force of the water current pushing the rotor backward. Furthermore, the number of bearings 8b on the rear side of the convex portion 4 may be greater than the number of bearings 8a on the front side of the convex portion 4 arranged around the rotor 10. By arranging more bearings 8b on the rear side of the convex portion 4, the number of points of contact between the convex portion 4 and the plurality of bearings 8b increases, which makes it possible to strengthen support against the force of the water flow pushing the rotor backward and also exerts the effect of suppressing the swinging of the rotor 10.

[0030] Furthermore, a waterproofing mechanism may be provided to prevent water from entering the cavity inside the rotor 10. The waterproofing mechanism may be a known waterproofing technique, and for example, as shown in FIG. 1, an O-ring 9 may be placed in the gap between the rotor 10 and the support member 3, thereby maintaining rotation while preventing water from entering the rotor.

[0031] 1, the rotor 10 is provided with a recess 7 and the support member 3 is provided with a protrusion 4, but the relationship between the recess and the protrusion may be reversed. That is, a recess may be provided on the support member 3 side, and a protrusion protruding radially inward from the inner wall surface of the rotor may face the recess of the support member 3.

[0032] (Second embodiment) Figure 2 is a diagram showing a water current power generation device according to a second embodiment. The second embodiment differs from the first embodiment in the number of convex portions and the shape of the rotor. As shown in Figure 2, by making the rotor 10 streamlined with a large diameter at the center of the body in the flow direction and tapering at the front and rear ends, the water current speed can be increased near the center of the body and directed to the blades, making it possible to obtain stable rotational power even with a short rotor. This reduces water current resistance and allows the energy of a high-speed water current to be efficiently converted into rotational energy.

[0033] Furthermore, the support member 3 has two protruding protrusions 4a and 4b, each of which is fitted with a recess 7a and 7b. Bearings 8a and 8b are located in front and behind the protrusions 4a and 4b, respectively. The height and thickness of the protrusions 4a and 4b may be the same, but the protrusion 4b can be made larger than the protrusion 4a to provide stronger support for the rotor at the rear. By making the rear protrusion 4b larger than the front protrusion 4a, even if the protrusion 4a is damaged, the protrusion 4b alone can support the rotor against the force of the water flow pushing it backward. Furthermore, varying the height and thickness of either the protrusion 4b or the protrusion 4a can prevent uniform up-and-down vibration of the rotor 10 and also suppress rocking of the rotor 10.

[0034] As shown in Fig. 2, by providing multiple convex portions 4 and concave portions 7, the number of points that support the rotor 10 increases, making it possible to stably support the rotor 10 even when the rotor 10 swings. Although not shown in Fig. 2, three wings may be provided radially at equal intervals around the barrel, twisted at a predetermined twist angle from the axial center of the barrel toward the rear end.

[0035] (Third embodiment) Figure 3 is a diagram showing a water current power generation device according to a third embodiment. Figure 4 is a perspective view of the water current power generation device shown in Figure 3. The support member is made up of a fixed plate 6 that fixes two support rods 3a, 3b parallel to the rotation axis of a rotor 10, and a recess 7 is formed on the surface of the fixed plate 6 facing the support pillar. The recess 7 is designed to receive the protrusion 4 protruding from the rear end of the rotor, and therefore has the effect of supporting the rotor 10 when it is swept downstream by the water current.

[0036] The main difference between the water current power generation device 1 of the third embodiment and the first embodiment is that the rotor 10 is supported by a fixed plate 6 that is fixed to a support 2 and supports two support rods 3a, 3b arranged outside the rotor 10.

[0037] The protrusion 4 in the third embodiment may be formed as a protrusion from the rear end of the rotor 10 as part of the rotor 10, or may be formed as a protrusion from the rear end of the rotor as the rear end of a shaft 5 that passes through the central axis of the rotor 10. In either case, the protrusion 4 rotates on the same rotation axis as the rotor 10.

[0038] A plurality of bearings 8 may be disposed in the space formed by the recessed portion 7 and the protruding portion 4 of the fixed plate 6. The presence of the bearings 8 reduces resistance to the rotational motion of the rotor 10, allowing it to rotate at a higher speed. The recessed portion 7 serves as a bearing for the protruding portion 4, and by disposing a bearing in the recessed portion 7 as described above, the rotor can be supported at its rear end while maintaining its rotation. The recessed portion 7 supports the rotor 10 by surrounding the shaft 5 extending from the rear end of the rotor 10.

[0039] The rear end of the shaft 5 may be in contact with the fixed plate 6, but because the frictional force between the rotating shaft 5 and the fixed plate 6 acts as resistance to rotation, it is also possible to arrange a bearing 8 inside the convex portion so that the rear end of the rotor 10 abuts against the bearing 8 and the rear end of the shaft 5 is spaced apart from the fixed plate 6. The presence of the bearing 8 allows for smooth rotation, and at the same time, because the bearing 8 supports the rear end of the rotor 10, it is effective in preventing the rotor 10 from shaking in strong water currents and being washed away.

[0040] 2, the rotating body 10 is provided with recesses 7a and 7b, and the support member 3 is provided with protrusions 4a and 4b, but the relationship of recesses and protrusions may be reversed. That is, a configuration may be adopted in which recesses are provided on the support member 3 side, and protrusions protruding radially inward from the inner wall surface of the rotating body face the recesses of the support member 3.

[0041] 3 and 4, the support member is composed of two support rods 3a, 3b and a fixed plate 6, but the number of support rods may be one or three or more. However, since the support rods 3a, 3b are located on the outside of the rotor 10, the support rods 3a, 3b act as resistance to the water flow, and if they reduce the water flow speed, the efficiency of conversion to rotational energy decreases. Therefore, it is desirable to use a small number of strong support rods, or to use multiple thin rods.

[0042] (Fourth embodiment) Figure 5 is a diagram showing a water current power generation device according to a fourth embodiment. The fourth embodiment differs from the third embodiment in that the recessed and protruding portions are reversed. That is, as shown in Figure 5, a recessed portion 7 may be formed at the rear end of the rotor 10 to receive the protruding portion 4 protruding from the fixed plate 6.

[0043] (Fifth embodiment) Figure 6 is a diagram showing a water current power generation device according to a fifth embodiment. In the water current power generation device 1 according to the first embodiment, the shaft 5 is directly connected to the generator 20 inside the support 2, whereas in the water current power generation device 1 according to the fifth embodiment, as shown in Figure 6, one end of the shaft 5 is a gear G1, which meshes with a gear G2 at the end of a transmission shaft 30 that extends downward from the generator on the water. Therefore, the rotation of the shaft 5 is converted into rotation of the transmission shaft 30 via the gears G1 and G2, and rotational energy can be transmitted to the generator 20 above. Installing a generator below the water surface, even if it is waterproof, can easily cause breakdowns and makes maintenance difficult. In the water current power generation device of the fifth embodiment, the generator 20 is installed above the water surface, which is effective in reducing generator breakdowns and improving maintainability.

[0044] (Sixth embodiment) Fig. 7 is a diagram showing a water current power generation device according to a sixth embodiment. In the fifth embodiment, there is one rotating body 10, but if there are two rotating bodies, the rotational energy of the multiple rotating bodies 10a, 10b can be converted into power generation energy by transmitting rotation to a generator via a differential gear as shown in Fig. 7.

[0045] Furthermore, although the configuration in which multiple rotating bodies are arranged vertically as shown in Figure 7 has been described, multiple rotating bodies can also be arranged horizontally if the above-mentioned differential gear is used.

[0046] Figure 8 shows an embodiment in which multiple rotors are connected to a single support pole. The shafts of each rotor may be directly connected to a generator located inside the support pole, or multiple rotors may be connected to a single support pole using multiple differential gears as shown in Figure 7, and the rotation may be transmitted to a generator located above the water surface. A low-speed, high-output generator, for example, one with a generating capacity of about 2000 kW, is preferred.

[0047] In the water current power generation device configured as described above, rotational power is obtained from the underwater rotor 10 that rotates along with the water current, and this rotational power is guided above the water surface via the transmission shaft 30, which then rotates the generator 20 to generate electricity. For example, if the underwater rotor is formed with a length of approximately 20 m and a rotational diameter of approximately 10 m as described above, and a water current power generation device equipped with this underwater rotor is placed in a water current of 3 knots, one rotor can generate approximately 500 kW.

[0048] As shown in FIG. 9 , the water current power generation device 1 of this embodiment includes a rectangular frame 40 constructed like a tower and an equipment mounting section 50 located at the center of the upper portion of the frame 40. The frame 40 is constructed in a rectangular shape using multiple upper horizontal members 40a at its upper end, multiple lower horizontal members 40b at its lower end, and multiple supports 2 connecting the upper and lower horizontal members 40a and 40b. The frame 40 may be fixed at its lower end to the water bottom G, or a rope R secured to an anchor 60 located on the water bottom G may support the frame 40 or a floating equipment mounting section 50. The equipment mounting section 50 is preferably a floating structure, allowing workers to inspect and maintain the equipment from the floating structure. A generator 20 can also be installed in the equipment mounting section 50. Positioning the generator 20 above the water surface S reduces the risk of generator 20 failure and facilitates maintenance. For example, the size of the equipment installation section 50 is formed in a rectangular shape with widths of about 50 m and heights of about 100 m.

[0049] When multiple rotating bodies are installed as shown in Figures 7 to 9, gears are not necessarily required. Each rotating body may be directly connected to a corresponding generator to generate electricity. In this case, for example, the amount of electricity generated by each rotating body can be stored via multiple cables connecting each generator to a power storage device installed in the equipment installation section 50. [Explanation of symbols]

[0050] 1...water current power generation device, 2...support, 3...support member, 3a, 3b...support rod, 4, 4a, 4b...convex portion; 5...shaft; 6...fixing plate; 7, 7a, 7b...concave portion; 8, 8a, 8b... bearing, 9... O-ring, 10, 10a, 10b... rotating body, 11... blade, 20... generator, 30... transmission shaft, 40... frame, 50... equipment arrangement section, 60, 60a, 60b, 60c...Anchor, S...Water surface, G...Bottom surface, G1, G2... gears, DG... differential gears, R1, R2, R3... ropes

Claims

1. A rotating body that rotates due to the water flow; a shaft that transmits the rotation of the rotor to a generator; a support post to which the shaft is rotatably mounted; a support member having one end fixed to the support column and the other end rotatably supporting the rotor, the support member is a cylindrical body extending in the direction of the rotation axis of the rotating body, A water current power generation transmission device characterized in that the rotating body is rotatably supported by a convex portion protruding radially outward from the support member facing a concave portion inside the rotating body.

2. A rotating body that rotates due to the water flow; a shaft that transmits the rotation of the rotor to a generator; a support post to which the shaft is rotatably mounted; a support member having one end fixed to the support column and the other end rotatably supporting the rotor, the support member is a cylindrical body extending in the direction of the rotation axis of the rotating body, A water current power generation transmission device characterized in that the rotating body is rotatably supported by a recess formed radially inward of the support member and a protrusion protruding from the inside of the rotating body facing each other.

3. A water current power generation device comprising a plurality of water current power generation transmission devices according to claim 1 or 2 attached thereto.

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