Power generation device

Abstract

A power generation device disclosed in the present application is characterized in that: the power generation device comprises a force-receiving rotor that is rotated by fluid force, a shaft base that rotates in conjunction with the rotation of the force-receiving rotor, a generator that generates power by the rotational force of the shaft base, and a bearing module that supports the generator, wherein the generator includes a rotor that is disposed outside the shaft base around the axis so as to rotate with the shaft base, and a stator that is disposed outside the shaft base around the axis so as not to rotate with the shaft base; the rotor and the stator are spaced apart in the axial direction of the shaft base; and the bearing module includes a bearing base that is disposed outside the shaft base around the axis so as not to rotate with the shaft base, a plurality of first load-receiving bodies that receive a load applied to the bearing base in a first direction and are disposed around the shaft base, and a plurality of second load receiving bodies that receive a load applied to the bearing base in a second direction.

Description

power generation equipment

[0001] The present invention relates to a power generation device, and more particularly to a power generation device that generates electricity by utilizing hydrodynamic forces such as wind power and tidal power.

[0002] Various types of power generation equipment that utilizes natural fluid energy such as wind power and tidal power are low-speed, high-torque equipment compared to steam turbines, etc. As such power generation equipment becomes larger, it becomes a large-diameter, flat generator, and it is known that the radial rigidity is relatively reduced and the shaft is subject to radial deformation due to external forces such as wind power and tidal power, as well as its own weight.

[0003] A conventional power generating device (Patent Document 1) is known as a technology for rotatably supporting a shaft while allowing radial deformation of the shaft, in which an external force is distributed and borne by multiple power generating units. In the power generating device described in Patent Document 1, gears that mesh with each other are provided on the shaft and each power generating unit.

[0004] When using gears, the radial position of the gear module fluctuates due to the gear's wobbling caused by external shaft deformation and coaxiality errors between the gear and shaft. This requires a movable mechanism for the meshing part to accommodate gear deformation, making the mechanism more complex. Furthermore, gear wear and tear are unavoidable, so maintenance such as periodic replacement is necessary. However, some power generation equipment, such as offshore wind power generation equipment, is installed in locations that are difficult to access, leaving room for improvement in terms of maintainability.

[0005] In recent years, gearless power generation devices with excellent maintainability have been devised, and one such device is an axial gap type generator in which a rotor and a stator are arranged with a gap in the axial direction (Patent Document 2). In this power generation device, a bearing is used to surround the outer diameter of the support column to support the rotating part (rotor) on the support column to which the stator is fixed.

[0006] International Publication No. 2020 / 230686 Japanese Patent Application Laid-Open No. 2020-089045

[0007] In recent years, devices that generate electricity using hydrodynamic forces have become larger, and as a result, the components of the power generation devices have also become larger. For example, in the case of offshore wind power generation devices, there have been reported developments in which the rotor diameter exceeds 7 meters and the generator weight exceeds several hundred tons. In order to support the rotor weight and hydrodynamic forces of such large-diameter generators with bearings, the support columns must be made larger in diameter, which requires a corresponding increase in bearing size.

[0008] However, large-diameter bearings that can accommodate such larger generators are difficult to manufacture or require high-precision processing or large-scale equipment, making them expensive. Therefore, with the method using bearings such as those disclosed in Patent Document 2, it is difficult to increase the size of power generation equipment at low cost.

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a power generating device that can be made large using an inexpensive bearing mechanism.

[0010] The power generation device disclosed in the present application comprises a force-receiving rotating body that rotates due to fluid force, a shaft base that rotates in conjunction with the rotation of the force-receiving rotating body, a generator that generates electricity using the rotational force of the shaft base, and a bearing module that supports the generator, wherein the generator comprises a rotor arranged on the outer side of the shaft base around the axis so as to rotate together with the shaft base, and a stator arranged on the outer side of the shaft base around the axis so as not to rotate together with the shaft base, the rotor and stator are spaced apart in the axial direction of the shaft base, and the bearing module comprises a bearing base arranged on the outer side of the shaft base around the axis so as not to rotate together with the shaft base, a plurality of first load receivers arranged around the shaft base that receive loads in a first direction related to the bearing base, and a plurality of second load receivers that receive loads in a second direction related to the bearing base.

[0011] The present invention includes a novel bearing module that replaces conventional bearings, allowing for a larger generator set to be built using a simple and inexpensive bearing mechanism.

[0012] FIG. 1 is an explanatory diagram of the overall configuration of an example of a power generating device of the present invention; FIG. 2 is an enlarged view of part II of FIG. 1; FIG. 3 is a perspective view of an example of a bearing module; FIG. 4 is a perspective view of an example of a rotor; FIG. 5 is a detailed explanatory view of the rotor of FIG. 4; FIG. 6 is a perspective view of an example of a stator (stator module); FIG. 7 is a perspective view of an example of a module assembly; and FIG. 8 is an explanatory bottom view of an example of a case in which the magnetic field of a permanent magnet is treated using a magnetic shield.

[0013] An example of an embodiment of a power generation device of the present invention will be described with reference to the drawings. Here, a floating wind power generation device in which a vertical axis wind turbine is connected to the tip of a float will be described as an example. Below, the structure, operation, and effects of the power generation device of this embodiment will be described, followed by a description of modified examples of the power generation device.

[0014] <Structure of the power generation device of this embodiment> As an example, a floating wind turbine power generation device shown in Figure 1 includes a float 10, a shaft base 20, a rotary wind turbine 30, a bearing support 40, a bearing module 50, a generator 60, and a mooring line 70.

[0015] The float 10 is a member that floats on water, such as on the ocean or on a lake. The float 10 in this embodiment is a hollow cylinder, and contains ballast material inside to maintain balance. The ballast material can be water, iron, rocks, or other materials.

[0016] 2, a shaft base 20 is provided on the tip side (upper end side in the illustrated example) of the floating body 10. A rotary wind turbine 30 is connected to the tip side (upper end side in the illustrated example) of the shaft base 20.

[0017] The shaft base 20 is a portion on which the generator 60 and the bearing module 50 are mounted, and does not necessarily have to be an independent member. For example, the shaft base 20 may be a part of the floating body 10 or a part of the shaft 31 of the rotary wind turbine 30.

[0018] The rotary windmill 30 is a member that rotates when it receives wind (a force-receiving rotor). The rotary windmill 30 in this embodiment is a vertical-axis type that includes a shaft 31, a plurality of arms 32 that protrude laterally from the shaft 31, and blades 33 that are attached to the tips of the arms 32.

[0019] A bearing support 40 that supports the bearing module 50 is provided at a position outside the shaft base 20 around the axis and closer to the floating body 10. The bearing support 40 in this embodiment is disk-shaped, and has an insertion hole in its center through which the shaft base 20 can be inserted.

[0020] The bearing support 40 is provided on the outer side around the axis of the shaft base 20 inserted through the insertion hole. The bearing support 40 is fixed to the shaft base 20 at the periphery of the insertion hole, and is configured to rotate in the same direction as the shaft base 20 as the shaft base 20 rotates.

[0021] The bearing module 50 is a member that supports the stator 62. In a broader sense, the bearing module 50 is a member that supports the generator 60 that includes the stator 62 and the rotor 61. That is, the bearing module 50 is a member that directly supports the stator 62 and indirectly supports the rotor 61 via the bearing support 40 and the shaft base 20. As shown in FIG. 3 , the bearing module 50 of this embodiment includes a bearing base 51, a plurality of first load receivers 52, and a plurality of second load receivers 53.

[0022] The bearing base 51 is a member that serves as the base of the bearing module 50. The bearing base 51 is disposed around the axis of the shaft base 20 on the outer side so as not to rotate together with the shaft base 20. The bearing base 51 in this embodiment has a triangular shape in a plan view, and is provided with mooring line attachment portions 51a that protrude outward at each corner.

[0023] The mooring line attachment portion 51 a has locking holes 51 b. One end of a mooring line 70 is attached to each locking hole 51 b. The other end of each mooring line 70 has an anchor (not shown) that is fixed to the seabed or lakebed at the installation location.

[0024] An insertion hole through which the shaft base 20 can be inserted is provided in the center of the bearing base 51. A plurality of first load receivers 52 are provided around the periphery of the insertion hole of the bearing base 51. The first load receivers 52 are members that receive a load (radial load) applied from the shaft base 20 in a first direction (the horizontal direction in the illustrated example), and are formed of horizontal rollers.

[0025] The second load receiving body 53 is a member that receives a load (axial load) in the second direction (vertical direction in the illustrated example) applied from the bearing support body 40, and is composed of vertical rollers. Specifically, one vertical roller is provided near the base of each of the three mooring rope attachment portions 51 a of the bearing base 51.

[0026] The bearing module 50 of this embodiment presses down (supports from above) the float 10 and the shaft base 20 and bearing support 40 connected to it to prevent them from floating up due to the buoyancy of the float 10 via the second load receiver 53, and holds the shaft base 20 horizontally via the first load receiver 52 to prevent the float 10 and shaft base 20 from moving horizontally.

[0027] Furthermore, the bearing module 50 holds the stator 62 so that the stator 62 does not rotate due to torque generated in the stator 62 as the shaft base 20 and the rotor 61 rotate. When the rotary wind turbine 30 receives wind, a horizontal force is applied to the bearing module 50 via the shaft base 20 connected to the rotary wind turbine 30.

[0028] Furthermore, when the rotary wind turbine 30 rotates, torque is applied to the bearing module 50 via the stator 62. The mooring lines 70 fix the bearing module 50 to the seabed to limit movement of the bearing module 50 that is subjected to these forces.

[0029] Furthermore, the first load receiver 52 and the second load receiver 53 rotatably support the shaft base 20 and the rotary wind turbine 30 and floating body 10 fixed thereto relative to the fixed bearing module 50 .

[0030] The generator 60 is a device that generates electricity using the rotational force generated by the rotary wind turbine 30. The generator 60 includes a rotor 61 and a stator 62 that are spaced apart in the axial direction of the shaft base 20.

[0031] The rotor 61 is a field magnet that generates a magnetic field. As shown in Figures 4 and 5, the rotor 61 of this embodiment includes a rotor base 61a and a permanent magnet 61b attached to the rotor base 61a. The rotor base 61a of this embodiment is disk-shaped and has an insertion hole at its center through which the shaft base 20 can be inserted.

[0032] The rotor base 61a is provided on the outer side around the axis of the shaft base 20 inserted through the insertion hole. The rotor base 61a is fixed to the shaft base 20 at the periphery of the insertion hole, and is configured to rotate in the same direction as the shaft base 20 as the shaft base 20 rotates.

[0033] In this embodiment, multiple bar-shaped magnets are used as the permanent magnets 61b. The multiple bar-shaped magnets are arranged radially from the center point of the shaft base 20. Existing neodymium magnets or the like can be used as the permanent magnets 61b. The multiple permanent magnets 61b are detachably mounted on the rotor base 61a.

[0034] The stator 62 is an armature that generates electricity in the magnetic field created by the permanent magnets 61b. The stator 62 is provided on the outer side of the shaft base 20 around the axis and facing the rotor 61. The stator 62 is provided at an interval from the rotor 61 in the axial direction of the shaft base 20.

[0035] 6, the stator 62 of this embodiment includes a plurality of stator modules 62a arranged in a ring shape. The stator modules 62a herein refer to the components (individual pieces) that make up the stator 62.

[0036] The stator module 62a is made up of a plurality of module components 62b arranged side by side. The stator module 62a made up of the plurality of module components 62b is a rectangular parallelepiped structure, and when arranged in a ring shape, a gap that is approximately trapezoidal in plan view is formed between adjacent stator modules 62a.

[0037] As shown in FIG. 7, each module component 62b constituting the stator module 62a includes a stator core 62c and a concentrated winding stator coil 62d wound around the stator core 62c.

[0038] In this embodiment, the stator core 62c is a long iron core that is T-shaped in end view, and the stator coil 62d is made of copper windings, although other materials may be used for the stator core 62c and the stator coil 62d.

[0039] The multiple stator modules 62a are detachably held by a stator holder 63. In this embodiment, the stator holder 63 is a disk-shaped member having an insertion hole in the center through which the shaft base 20 can be inserted. The stator holder 63 is supported by the bearing module 50 with the shaft base 20 inserted into the insertion hole.

[0040] In this embodiment, the stator module 62a can be inserted and removed (attached and detached) by sliding it radially of the stator holder 63. As described above, in this embodiment, when the stator modules 62a are arranged in a ring shape, a gap that is approximately trapezoidal in plan view (a dimensional margin) is formed between adjacent stator modules 62a, so that the stator modules can be easily removed radially.

[0041] In addition, when the rotor 61 is provided with the permanent magnets 61b as in this embodiment, the magnetic field of the permanent magnets 61b needs to be appropriately treated when attaching or detaching the stator module 62a or the permanent magnets 61b.

[0042] One example of a method for handling the magnetic field is to place a magnetic shield 64 (FIG. 8) that blocks the magnetic field of the permanent magnet 61b provided on the rotor base 61a at a position that blocks the magnetic field of the permanent magnet 61b when attaching or detaching the stator module 62a.

[0043] The magnetic shield 64 is a magnetic material that short-circuits the magnetic flux generating surfaces of at least one N-S pole pair. The magnetic shield 64 may be any material that can block the magnetic field of the permanent magnet 61 b, and may be, for example, a metal cover that has a shielding effect, such as iron or nickel.

[0044] For example, when removing the stator module 62a, the magnetic shield 64 is placed over the permanent magnets 61b of the N-S pole pair that affect the stator module 62a to be removed, the magnetic flux generating surfaces of the permanent magnets 61b of the N-S pole pair are short-circuited, and the stator module 62a is then pulled out radially outward, thereby removing the stator module 62a. Note that when removing the permanent magnet 61b, the magnetic flux generating surfaces of the permanent magnet 61b are short-circuited in a similar manner, and the permanent magnet 61b is then pulled out radially outward.

[0045] <Operation of the power generating device of this embodiment> In the power generating device configured as described above, when the rotary wind turbine 30 is rotated by wind power, the rotational force rotates the shaft base 20, and the rotor 61 rotates together with the shaft base 20. When the rotor 61 rotates, an induced current flows in the stator coil 62d on the stator 62 side due to electromagnetic induction, and electric power is generated.

[0046] <Effects of the power generating device of this embodiment> The power generating device of this embodiment has the following various effects. Note that the effects described below are effects that are achieved depending on the configuration of the power generating device, and are not necessarily effects that are always achieved by the power generating device of the present invention.

[0047] In the power generation device of this embodiment, a bearing module 50 is used that can be positioned around the outside of the shaft base 20 regardless of the diameter (thickness) of the shaft base 20, so it is possible to increase the size of the power generation device beyond the range that can be accommodated by existing bearings.

[0048] Furthermore, the power generating device of this embodiment is equipped with a so-called axial gap type generator in which the rotor 61 and stator 62 are arranged at a distance in the axial direction of the shaft base 20. This has the advantage that even if the shaft base 20 is deformed by external forces or its own weight, the air gap between the rotor 61 and the stator 62 can be easily maintained at a width suitable for power generation.

[0049] Furthermore, the power generation device of this embodiment has a gearless configuration, which eliminates the need for periodic gear replacement, and therefore has the advantage of requiring less maintenance than a gear-type power generation device, which is particularly advantageous when the device is installed in a location that is difficult to access, such as an offshore wind power generation device.

[0050] In this embodiment, the stator 62 is composed of stator modules 62a, and the core and windings of the generator can be manufactured in modular units, so the generator can be manufactured using small manufacturing facilities. Furthermore, if a part of the stator module 62a is damaged after operation, only the damaged stator module 62a can be replaced, resulting in excellent manufacturability and maintainability. Furthermore, the remaining stator modules 62a can continue to be used, resulting in excellent economic efficiency.

[0051] In addition, in this embodiment, since the multiple permanent magnets 61b are detachable from the rotor base 61a, if one of the permanent magnets 61b is damaged, only the damaged permanent magnet 61b can be replaced, which is easy to maintain.Furthermore, since the permanent magnets 61b other than the damaged one can continue to be used, it is also economical.

[0052] <Modifications of the Power Generator> The configuration of the above embodiment is an example, and the configuration of the power generator of the present application is not limited to the configuration of the above embodiment. The power generator of the present application can be modified, such as by omitting, replacing, or adding components, to the extent that the intended purpose can be achieved. For example, the following modifications are envisioned.

[0053] In the above embodiment, the force-receiving rotating body is an example of a rotary wind turbine 30, but the force-receiving rotating body may be anything other than a rotary wind turbine 30 as long as it rotates by receiving the force of a fluid (gas or fluid), specifically, natural energy such as wind power or water power (including tidal power).

[0054] In the above embodiment, the rotary wind turbine 30 is a vertical axis type, but the rotary wind turbine 30 may be a horizontal axis type. Also, the rotary wind turbine 30 may be a lift type or a drag type.

[0055] In the above embodiment, a floating wind power generation system in which the power generation system floats on the ocean is used as an example, but the power generation system of the present invention can be configured as an on-water power generation system installed on water such as the ocean or a lake, or as a land-based power generation system installed on land.

[0056] In the above embodiment, the case where one generator 60 is provided is taken as an example, but two or more generators 60 may be provided in the axial direction of the shaft base portion 20. In this case, it is preferable that the two or more generators 60 are arranged so as to cancel out the magnetic forces of the rotors 61 of adjacent generators 60.

[0057] When two or more generators 60 are provided, the orientation of each generator 60 may be the same or opposite. Furthermore, when two or more generators 60 are provided, a bearing support 40 and a bearing module 50 may be provided for each generator 60, but it is also possible to provide the bearing support 40 and the bearing module 50 only for the generator 60 at the lowest stage, and omit these for the generators at the second stage and thereafter.

[0058] The embodiments disclosed herein are merely examples and are not intended to limit the scope of the power generation device of the present invention. The technical scope of the power generation device of the present invention is defined by the claims. The technical scope of the present invention also includes equivalents to the claims. For example, although the present application defines a first load receiver and a second load receiver, adding a third load receiver, a fourth load receiver, etc., in addition to these load receivers, and multiple load receivers with similar configurations that receive the main load, naturally falls within the scope of equivalents of the present application.

[0059] The power generation device disclosed in this application can be applied to various power generation devices, and is particularly suitable for use in large floating vertical axis type water-based wind power generation devices with large diameter shafts that are floated on water such as the ocean or lake.

[0060] REFERENCE SIGNS LIST 10 Floating body 20 Shaft base 30 Rotating wind turbine (force-receiving rotating body) 31 Shaft 32 Arm 33 Blade 40 Bearing support 50 Bearing module 51 Bearing base 51a Mooring line attachment portion 51b Locking hole 52 First load receiver 53 Second load receiver 60 Generator 61 Rotor 61a Rotor base 61b Permanent magnet 62 Stator 62a Stator module 62b Module structure 62c Stator core 62d Stator coil 63 Stator holder 64 Magnetic shield 70 Mooring line

Claims

1. A power generation device comprising: a force-receiving rotating body that rotates due to fluid force; a shaft base that rotates in conjunction with the rotation of the force-receiving rotating body; a generator that generates electricity using the rotational force of the shaft base; and a bearing module supporting the generator, wherein the generator comprises a rotor arranged on the outer side of the shaft base around the axis so as to rotate together with the shaft base, and a stator arranged on the outer side of the shaft base around the axis so as not to rotate together with the shaft base, the rotor and stator being spaced apart in the axial direction of the shaft base, and the bearing module comprising: a bearing base arranged on the outer side of the shaft base around the axis so as not to rotate together with the shaft base, a plurality of first load receivers arranged around the shaft base that receive a load in a first direction related to the bearing base, and a plurality of second load receivers that receive a load in a second direction related to the bearing base.

2. The power generating device according to claim 1, wherein the load in the first direction is a horizontal load on the bearing base, and the load in the second direction is a vertical load on the bearing base.

3. The power generating device according to claim 1, further comprising a bearing support that rotates together with the shaft base, the bearing module being supported by the bearing support.

4. The power generating device according to claim 1, wherein the stator comprises a plurality of stator modules arranged in an annular shape.

5. The power generating device according to claim 1, further comprising a stator holder disposed around the axis of the shaft base on the outer side so as not to rotate together with the shaft base, and wherein the plurality of stator modules are provided so as to be insertable and detachable in the radial direction of the stator holder.

6. The power generating device according to claim 5, wherein the rotor comprises a rotor base that rotates together with the shaft base and a plurality of permanent magnets, and a magnetic shield that is positioned to block the magnetic field of the permanent magnets when the stator module attached to the stator holder is attached or detached, and that blocks the magnetic field of the permanent magnets.

7. The power generating device according to claim 1, wherein the rotor comprises a rotor base that rotates together with the shaft base and a plurality of permanent magnets, the plurality of permanent magnets being detachably attached to the rotor base.

8. The power generating device according to claim 7, further comprising a magnetic shield that is positioned to block the magnetic field of the permanent magnet when the permanent magnet is attached to the rotor base or removed.

9. The power generating device according to claim 1, wherein the shaft base is connected to a float floating on water.

10. The power generating device according to claim 9, wherein the bearing base is provided with a mooring line attachment portion for attaching a mooring line.

11. A power generating device according to any one of claims 1 to 10, wherein two or more generators are provided in the axial direction of the shaft base.

12. The power generating device according to claim 11, wherein the two or more generators are arranged so as to cancel out the magnetic forces of the rotors of adjacent generators.

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