JP7535271B2 - Floating Vertical Axis Turbine - Google Patents

Description

This technology relates to floating vertical axis turbines.

Conventionally, vertical axis wind turbines with a vertical axis of rotation have been disclosed. Vertical axis wind turbines can convert wind force into rotational force even when the wind direction changes, and are not affected by the wind direction (see, for example, Patent Document 1).

European Patent Application Publication No. 2080899

When large vertical axis wind turbines are used to generate wind power offshore, wave loads act on the vertical axis wind turbine, causing its shaft to deform. Bearings are used to support the shaft, but conventional bearings are designed on the assumption that the shaft has high rigidity, and are not designed to allow the shaft to deform. For this reason, it is difficult to apply conventional bearings to the shaft of a vertical axis wind turbine.

This disclosure has been made in consideration of the above circumstances, and aims to provide a floating vertical axis turbine having a bearing device that can be applied to a large shaft.

The floating vertical axis turbine of the present disclosure comprises a floating body, a shaft connected to the floating body and rotatable about an axis, blades connected to the shaft, and a bearing device supporting the shaft and including a plurality of bearing units.

In this disclosure, wave loads are distributed and borne by multiple bearing units to accommodate shaft deformation.

In the floating vertical axis turbine of the present disclosure, the bearing unit has a support mechanism for receiving wave loads acting on the shaft.

In the present disclosure, the bearing unit bears wave loads through a support mechanism.

The floating vertical axis turbine of the present disclosure has a protrusion protruding radially from the shaft, and the support mechanism has a first roller that supports the outer circumferential surface of the shaft and rotates about an axis parallel to the shaft, and a second roller that supports the blade side of the protrusion and rotates about an axis intersecting the shaft.

In the present disclosure, the support mechanism bears the radial load through a first roller and the axial load through a second roller.

In the floating vertical axis turbine of the present disclosure, the bearing unit has a positioning mechanism for positioning the shaft.

In the present disclosure, the relative position of the shaft and the bearing unit is adjusted using a positioning mechanism.

In the floating vertical axis turbine of the present disclosure, the positioning mechanism has a third roller that supports the floating side of the protrusion and rotates around an axis that intersects the shaft.

In the present disclosure, the third roller supports the floating body side of the protrusion and positions the shaft, which sways due to wave forces.

In the floating vertical axis turbine of the present disclosure, the protruding portion includes a first gear having a gear portion on its outer periphery, a second gear that meshes with the first gear and outputs to a power generation section, and a biasing section that biases the second gear toward the first gear.

In the present disclosure, the gap between the first gear and the second gear is adjusted by the biasing force of the biasing section, and the rotational force of the shaft is efficiently transmitted to the power generating section.

In the floating vertical axis turbine according to the present disclosure, wave loads are distributed and borne by multiple bearing units. It is also easier to design the turbine to tolerate shaft deformation, and it is possible to accommodate shaft deformation.

FIG. 1 is a simplified perspective view of a floating wind turbine generator according to a first embodiment. FIG. 2 is a schematic perspective view of a generator arranged around a shaft. FIG. 2 is a simplified exploded view of a generator set arranged around a shaft. FIG. 2 is a schematic perspective view of a power generation unit. FIG. 2 is a schematic perspective view of a single power generating unit and a shaft. FIG. 2 is a schematic plan view of a single power generating unit and shaft. 7 is a schematic cross-sectional view taken along line VII-VII in FIG. 6. FIG. 11 is a schematic vertical cross-sectional view of a single power generating unit and a shaft of a floating wind turbine generator according to a second embodiment. FIG. 11 is a schematic vertical cross-sectional view of a single power generation unit and a shaft of a floating wind turbine generator according to a third embodiment.

(Embodiment 1)
The present invention will be described below with reference to the drawings showing a floating wind power generator according to a first embodiment. Fig. 1 is a schematic perspective view of a floating wind power generator 1. The floating wind power generator 1 comprises a hollow cylindrical float 2, a shaft 3, a power generation device 4, a rope 5, wings 6, and an arm 7. The float 2 floats on water such as the sea or a lake. Ballast materials such as water, iron materials, and rocks are placed inside the float 2, and a portion of it is located below the water surface. The power generation device 4 constitutes a bearing device.

The shaft 3 is coaxially connected to the portion of the float 2 that protrudes above the water surface. The shaft 3 is made of steel, fiber-reinforced plastic, or aluminum. A plurality of arms 7 protrude radially from the shaft 3. The arms 7 are arranged at approximately equal intervals along the axial direction and at approximately equal phase intervals in the circumferential direction. In this embodiment, three arms 7 are arranged at phase intervals of approximately 120 degrees in the circumferential direction, and four arms are arranged along the axial direction. Each arm 7 has approximately the same length and is shaped like a flattened column.

The wings 6 are attached to the ends of three arms 7 arranged in the axial direction. The wings 6 are flat and columnar extending along the shaft 3, and have a wing cross-sectional shape in a plan view. Fiber-reinforced plastic material is used for the wings 6 and arms 7, and because the wings 6 and arms 7 are flat and have a uniform shape in the longitudinal direction, they can be manufactured continuously at high speed, reducing manufacturing costs. The wings 6 and arms 7 can also be made lighter. Aluminum material may be used instead of the fiber-reinforced plastic material.

Between the arm 7 and the floating body 2, the power generation device 4 is attached to the outer periphery of the shaft 3. The power generation device 4 is tethered by a number of ropes 5, and rotation of the power generation device 4 around its axis is restricted.

When wind force acts on the blades 6, the float 2 and shaft 3 rotate around their axes. On the other hand, the power generation device 4 does not rotate. In other words, the shaft 3 and the power generation device 4 rotate around their axes relative to each other, and the power generation device 4 generates electricity through the rotation of the shaft 3.

Figure 2 is a simplified perspective view of the power generation device 4 arranged around the shaft 3, Figure 3 is a simplified exploded view of the power generation device 4 arranged around the shaft 3, and Figure 4 is a simplified perspective view of the power generation unit 10. As shown in Figure 2, the power generation device 4 has multiple (three in this embodiment) power generation units 10, which surround the outer periphery of the shaft 3. The power generation units 10 form a bearing unit.

As shown in Figure 3, the shaft 3 comprises a large diameter gear 30 and a positioning passage 31. The large diameter gear 30 forms an annular shape protruding radially outward from the shaft 3. The positioning passage 31 is formed in an annular shape around the entire outer circumference on the outer circumferential surface of the shaft 3. The positioning passage 31 is adjacent to the large diameter gear 30 in the axial direction. The large diameter gear 30 is arranged on the wing 6 side, and the positioning passage 31 is arranged on the floating body 2 side. The large diameter gear 30 constitutes a protrusion and a first gear.

As shown in FIG. 4, the power generation unit 10 includes a rectangular first frame 11. The first frame 11 extends along the axial direction of the shaft 3. Two storage chambers 12 are formed in the first frame 11. The two storage chambers 12 are aligned in the longitudinal direction of the first frame 11. The storage chambers 12 penetrate the first frame 11 in the radial direction of the shaft 3. A first roller 13 is rotatably stored in each storage chamber 12. The rotational axis direction of the first roller 13 corresponds to the axial direction of the shaft 3.

A connecting portion 21 and a connected portion 22 each protrude from the two long sides of the first frame 11. The connecting portion 21 and the connected portion 22 are inclined relative to the first frame 11, and when viewed from the axial direction, the first frame 11, the connecting portion 21 and the connected portion 22 form a U-shape. The first frame 11, the connecting portion 21 and the connected portion 22 are arranged to surround a portion of the outer circumference of the shaft 3.

A second frame 14 is provided on a short side of the first frame 11. The second frame 14 has a portion that protrudes radially inward from the shaft 3, and a storage chamber 14a is formed in the protruding portion. The storage chamber 14a penetrates the shaft 3 in the axial direction, and a second roller 15 is rotatably stored in the storage chamber 14a. The rotational axis direction of the second roller 15 corresponds to the radial direction of the shaft 3. The first roller 13 and the second roller 15 correspond to a support mechanism.

A support portion 16 is formed at the connection between the long side of the first frame 11 from which the connected portion 22 protrudes and the short side of the first frame 11 on which the second frame 14 is provided. The support portion 16 is cylindrical, and its axial direction corresponds to the axial direction of the shaft 3. A pivot 17 protrudes from the center of the support portion 16 in the axial direction.

The power generation unit 10 is equipped with a support arm 18. The support arm 18 is in the form of a rectangular plate perpendicular to the pivot 17, and each short side of the support arm 18 forms an arc shape that protrudes outward. One end of the support arm 18 is rotatably attached to the pivot 17. A hook 18a is formed on the long side of the support arm 18. The hook 18a is positioned radially opposite the shaft 3. The tip of the hook 18a is directed toward the second frame 14.

The power generating unit 19 is supported on one surface of the other end of the support arm 18, and the small diameter gear 20 is supported on the other surface of the other end. The small diameter gear 20 constitutes a second gear. In the axial direction of the pivot 17, the power generating unit 19 is arranged on the second frame 14 side, and the small diameter gear 20 is arranged on the first frame 11 side. The power generating unit 19 is cylindrical, and the power generating unit 19 and the small diameter gear 20 are arranged coaxially. A positioning disk 20a is provided coaxially on the small diameter gear 20. In the axial direction, the positioning disk 20a is arranged on the opposite side of the power generating unit 19. The small diameter gear 20 rotates with the axial direction of the pivot 17 as the rotation axis. By the rotation of the small diameter gear 20, the power generating unit 19 generates electricity, and the positioning disk 20a rotates in the same direction as the small diameter gear 20.

Figure 5 is a simplified perspective view of a single power generating unit 10 and shaft 3, Figure 6 is a simplified plan view of a single power generating unit 10 and shaft 3, and Figure 7 is a simplified cross-sectional view taken along line VII-VII in Figure 6. As shown in Figure 5, the power generating unit 10 is attached to the shaft 3 so that the second roller 15 faces the side of the large diameter gear 30, the small diameter gear 20 meshes with the large diameter gear 30, and the positioning disk 20a faces the positioning path 31, and as shown in Figure 7, the first roller 13 faces the outer circumferential surface of the shaft 3. The shaft 3 is rotatably supported by the first roller 13 and the second roller 15.

As shown in Figure 2, each of the multiple power generation units 10 is attached to the shaft 3 as described above. In two power generation units 10 adjacent to each other in the circumferential direction of the shaft 3, the connecting portion 21 of one power generation unit 10 is connected to the connected portion 22 of the other power generation unit 10.

As shown in Figure 2, a biasing part 50 is provided between the connecting part 21 of one power generating unit 10 and the connected part 22 of the other power generating unit 10. The biasing part 50 includes a pin 51 protruding from the connecting part 21 in the axial direction of the shaft 3, and a spring 52. Hooks 52a, 52b are formed on both ends of the spring 52. One hook 52a is hooked onto the pin 51, and the other hook 52b is hooked onto the hook 18a.

The spring 52 is a tension spring, and the biasing force of the spring 52 rotates the support arm 18, and the small diameter gear 20 approaches the large diameter gear 30. The positioning disk 20a abuts against the positioning path 31, ensuring a gap (backlash) between the small diameter gear 20 and the large diameter gear 30. In other words, the positioning disk 20a and the positioning path 31 position the small diameter gear 20 and the large diameter gear 30 in the radial direction. Note that instead of the spring 52, other biasing members such as rubber or hydraulic cylinders may be used, and magnetic force may be used as the biasing force of the biasing unit 50.

The shaft 3 sways due to wave forces, and wave loads (mooring tension) act on the shaft 3. The wave loads can be 10 times or more the thrust that a wind turbine receives from the wind, and the shaft 3 can deform. Conventional bearings are designed by regarding the shaft as a rigid body, and cannot be applied to the deforming shaft 3. Even if a shaft 3 with a total length of about 100 m is made of a highly rigid material such as steel, the diameter of the shaft 3 will be about 7 m, and the bearings will have to be large. Designing the shaft 3 to be highly rigid is not realistic from the perspective of manufacturing costs, and it is desirable to manufacture the shaft 3 from a lightweight composite material such as reinforced fiber plastic or aluminum, which allows for a certain degree of deformation of the shaft 3.

On the other hand, in order to realize efficient and sustainable power generation regardless of wave load, it is necessary to precisely control the gap between the small diameter gear 20 and the large diameter gear 30, for example, to keep the gap within an error range of a few millimeters. The deformation amount of the shaft 3 described above is larger than the gap between the small diameter gear 20 and the large diameter gear 30 that is permissible for power generation. Therefore, it is necessary to achieve both a configuration that allows deformation of the shaft 3 under wave load and a configuration that controls the gap between the small diameter gear 20 and the large diameter gear 30.

In the floating wind turbine 1 according to the first embodiment, the wave load is distributed to the multiple power generating units 10 and is borne by the multiple power generating units 10 as a whole. Specifically, in each of the multiple power generating units 10, the first roller 13 receives the radial wave load (radial load), and the second roller 15 receives the axial wave load (axial load). Therefore, even if a large wave load acts, the first roller 13 and the second roller 15 in each power generating unit 10 can rotatably support the shaft 3 while allowing deformation of the shaft 3.

In addition, since it includes multiple power generating units 10, the power generating device 4 is easy to design to tolerate deformation of the shaft 3. Even if a malfunction occurs in any of the power generating units 10, the other power generating units 10 can continue to generate electricity, and only the malfunctioning power generating unit 10 needs to be repaired or replaced, improving the reliability of the power generating device 4. In addition, the relative positions of the shaft 3 and the power generating units 10 can be adjusted by the first roller 13 and the second roller 15.

(Embodiment 2)
The present invention will be described below with reference to the drawings showing a floating wind turbine generator 1 according to embodiment 2. Among the components according to embodiment 2, the same components as those in embodiment 1 are given the same reference numerals, and detailed description thereof will be omitted.

Figure 8 is a schematic longitudinal cross-sectional view of a single power generating unit 10 and shaft 3. The power generating unit 10 is equipped with a third roller 15a whose rotation axis direction is the radial direction of the shaft 3. The third roller 15a is connected, for example, to the connecting part 21 or the connected part 22. The third roller 15a is disposed on the opposite side of the second roller 15 in the axial direction, and faces the side of the large diameter gear 30. That is, the second roller 15 faces one side of the large diameter gear 30, and the third roller 15a faces the other side.

In the second embodiment, the third roller 15a can perform relative positioning of the small diameter gear 20 and the large diameter gear 30. The third roller 15a constitutes a positioning mechanism.

(Embodiment 3)
The present invention will be described below with reference to the drawings showing a floating wind turbine generator 1 according to embodiment 3. Among the components according to embodiment 3, the same components as those in embodiment 1 or 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

Figure 9 is a schematic longitudinal cross-sectional view of a single power generation unit 10 and shaft 3. The shaft 3 comprises an axial body 3a and a cylindrical portion 3b. The cylindrical portion 3b protrudes from the side of the large diameter gear 30 toward the float 2 along the axial direction. The cylindrical portion 3b is provided coaxially on the outside of the axial body 3a. A positioning passage 31 is formed on the outer peripheral surface of the cylindrical portion 3b.

The first frame 11 has an outer portion 11a arranged outside the cylindrical portion 3b and an inner portion 11b arranged inside the cylindrical portion 3b. The inner portion 11b is arranged between the shaft body 3a and the cylindrical portion 3b. The outer portion 11a and the inner portion 11b are connected. The outer portion 11a is provided with a storage chamber 12 and a first roller 13.

A plurality of second storage chambers 12a are formed in the inner portion 11b. The number of the second storage chambers 12a is the same as the number of the storage chambers 12. The plurality of second storage chambers 12a are arranged in the axial direction and penetrate the inner portion 11b in the radial direction. The second storage chambers 12a are radially opposed to the storage chambers 12. A roller 13a with its rotation axis in the axial direction is stored in the second storage chamber 12a.

In embodiment 3, roller 13a and first roller 13 are arranged opposite each other on the inner and outer circumferential sides of cylindrical portion 3b, so that radial wave loads can be borne not only by first roller 13 but also by roller 13a.

Although not shown in the figure, the floating wind turbine 1 described above is provided with a cover to protect the shaft 3, blades 6, arms 7, connecting ring 9, power generation device 4, etc. from moisture, such as seawater splashes.

The floating wind turbine 1 described above is merely one example of a floating vertical axis turbine, and the above configuration may be applied to a floating ocean current turbine or a floating tidal current turbine. The floating wind turbine 1 generates electricity by meshing gears provided on the shaft 3 and the power generation device 4, but electricity may also be generated by providing electromagnets and coils on the shaft 3 and the power generation device 4. A device may also be provided to supply lubricating oil to contact points between parts, such as the contact points between the large diameter gear 30 and the small diameter gear 20, or the contact points between the first roller 13 and the positioning path 31.

The embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The technical features described in each embodiment can be combined with each other, and the scope of the present invention is intended to include all modifications within the scope of the claims and equivalents to the scope of the claims.

Reference Signs List 1 Floating wind turbine generator 2 Floating body 3 Shaft 3a Shaft body 3b Cylindrical part 4 Power generating device (bearing device)
10 power generating unit 13 first roller (support mechanism)
13b Roller 15 Second roller (support mechanism)
15a Third roller (positioning mechanism)
18 Support arm 18a Hook 19 Power generating unit 20 Small diameter gear (second gear)
20a Positioning disc 30 Large diameter gear (first gear)
50: biasing portion 51: pin 52: spring 52a, 52b: hook

Claims (5)

A floating body,
A shaft connected to the float and rotatable about an axis;
a blade connected to the shaft;
a bearing device including a plurality of bearing units arranged in a circumferential direction of the shaft so as to surround an outer periphery of the shaft and supporting the shaft,
The bearing unit has a support mechanism for receiving a wave load acting on the shaft,
A protrusion protruding from the shaft in a radial direction is provided.
The support mechanism includes:
A first roller supports an outer peripheral surface of the shaft and rotates about an axis parallel to the shaft;
a second roller supporting the blade side of the protrusion and rotating about an axis intersecting the shaft;
A floating vertical axis turbine having a The bearing unit includes:
The floating vertical axis turbine according to claim 1 , further comprising a positioning mechanism for positioning the shaft. The positioning mechanism includes:
3. The floating vertical axis turbine according to claim 2 , further comprising a third roller supporting the floating body side of the protruding portion and rotating about an axis intersecting with the shaft. The protrusion includes a first gear having a gear portion on an outer periphery,
a second gear that meshes with the first gear and outputs to a power generating unit;
The floating vertical axis turbine according to claim 1 , further comprising : a biasing portion that biases the second gear toward the first gear. A floating body,
A shaft connected to the float and rotatable about an axis;
a blade connected to the shaft;
a bearing device including a plurality of bearing units arranged in a circumferential direction of the shaft so as to surround an outer periphery of the shaft and supporting the shaft;
Equipped with
The bearing unit has a support mechanism for receiving a wave load acting on the shaft,
The shaft includes a shaft body and a cylindrical portion provided coaxially on the outside of the shaft body,
The support mechanism includes:
an outer roller disposed radially outside the cylindrical portion and rotating about an axis parallel to the shaft;
an inner roller disposed inside the cylindrical portion in the radial direction and rotating about an axis parallel to the shaft.

Images