Power generation device

Abstract

The problem addressed by the present invention is to provide a power generation device having a structure capable of suppressing a burden of winding work and a cost burden, and also suitable for enlargement. The power generation device according to the present invention is characterized by comprising a force-receiving rotor that rotates when receiving a fluid force, a shaft base part that rotates in conjunction with the rotation of the force-receiving rotor, and a generator that generates power by means of the rotational force of the shaft base part, and is characterized in that: the power generator is provided with a rotor disposed so as to rotate together with the shaft base part on the outer side of the shaft base part around a shaft, a stator disposed on the outer side of the shaft base part around the shaft so as not to rotate together with the shaft base part, and an excitation body disposed on the outer side of the shaft base part around the shaft so as not to rotate together with the shaft base part; the rotor is provided with a rotor base that is fixed to the shaft base part and rotates together with the shaft base part, and a plurality of magnetic pole cores that are arranged annularly on the rotor base; and the excitation body is provided with an annular field coil that excites the magnetic pole core.

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] A known type of power generating device includes a salient pole field generator (see Patent Document 1). Patent Document 1 discloses that an exciter is used to supply power to the rotor, and that salient poles are wound around cores to form field poles.

[0003] Japanese Patent Application Laid-Open No. 2004-159436

[0004] In recent years, components that are subject to fluid force, such as rotary wind turbines, have become larger, more multi-pole, and larger in diameter, and as a result, the size of generators has also increased to a level exceeding 10 m.

[0005] In a generator equipped with the aforementioned salient-pole rotor, the number of poles of the rotor's field winding increases as the generator size increases, increasing the burden of winding work per pole. Furthermore, as the generator size increases, the winding equipment must also be made larger, which increases the cost burden.

[0006] The present invention has been made in consideration of the above circumstances, and the problem to be solved is to propose a power generating device that can reduce the burden and cost of winding work and has a structure that is suitable for large-scale operation.

[0007] The power generating device of the present invention comprises a force-receiving rotor that rotates when subjected to fluid force, a shaft base that rotates in conjunction with the rotation of the force-receiving rotor, and a generator that generates electricity using the rotational force of the shaft base, wherein the generator comprises a rotor arranged on the outside of the shaft base around its axis so as to rotate together with the shaft base, a stator arranged on the outside of the shaft base around its axis so as not to rotate together with the shaft base, and an exciter arranged on the outside of the shaft base around its axis so as not to rotate together with the shaft base, the rotor comprises a rotor base fixed to the shaft base and rotating together with the shaft base, and a plurality of magnetic pole cores arranged in a ring shape on the rotor base, and the exciter comprises a ring-shaped field coil that excites the magnetic pole cores.

[0008] The power generator of the present invention does not require winding work on the rotor, so the burden and cost of winding work can be reduced, and the power generator can also be made larger.

[0009] 1 is an explanatory diagram of the overall configuration of an example of a power generating device of the present invention; an enlarged view of part II of FIG. 1; a perspective view of an example of a bearing module; a perspective view of an example of a bearing module and a generator; a perspective view of an example of a rotor; (a) is a perspective view of an example of a rotor base, and (b) is a perspective view of an example of an magnetic pole core. a perspective view of an example of a stator part; (a) is a partial detailed view of the generator shown in FIG. 4, and (b) is a perspective view of an example of an excitation core. (a) is a perspective view of an example of an connecting unit, and (b) is a cross-sectional view of the rotor fitted in the air gap of the connecting unit. (a) and (b) are explanatory views showing an example of a procedure for removing the stator part; an explanatory view showing the flow of magnetic flux; (a) is a perspective view of another example of a rotor base, and (b) is a partial detailed view of the rotor base of (a); an explanatory view showing an example of a case where generators are installed in multiple stages; an explanatory view showing an example of a case where the power generating device of the present invention is applied to a horizontal axis wind power generating device; an explanatory view showing an example of a case where the power generating device of the present invention is applied to a vertical axis tidal power generating device.

[0010] 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.

[0011] <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.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] The rotary windmill 30 is a member that rotates when it receives wind force (a force-receiving rotor). The rotary windmill 30 in this embodiment is a vertical axis type, and 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.

[0016] 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.

[0017] 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.

[0018] 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. In other words, 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.

[0019] As shown in FIG. 3 , the bearing module 50 of this embodiment includes a bearing base 51 , a first load receiver 52 , and a second load receiver 53 .

[0020] 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.

[0021] The mooring line attachment portion 51a is provided with locking holes 51b. One end of a mooring line 70 is attached to each locking hole 51b. The other end of each mooring line 70 is provided with an anchor (not shown) and is fixed to the seabed or lakebed at the installation location.

[0022] 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) in a first direction (horizontal direction in the illustrated example) applied from the shaft base 20, and are composed of a group of a plurality of horizontal rollers.

[0023] 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 a group of multiple 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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 .

[0028] The generator 60 is a device that generates electricity using the rotational force generated by the rotary wind turbine 30. As shown in FIG.

[0029] The rotor 61 is arranged on the outer periphery of the shaft base 20 (Figure 2) so as to rotate together with the shaft base 20, and the stator 62 and the exciter 65 are arranged on the outer periphery of the shaft base 20 so as not to rotate together with the shaft base 20.

[0030] The rotor 61 is a field magnet that generates a magnetic field. As shown in Fig. 5, the rotor 61 of this embodiment includes a rotor base 61a and a plurality of (26 in this embodiment) magnetic pole cores 61c attached to the rotor base 61a.

[0031] The rotor base 61a is a member that holds the magnetic pole core 61c and can be made of a non-magnetic, insulating material such as FRP (fiber reinforced plastic). As shown in Figure 6(a), the rotor base 61a in this embodiment is disk-shaped and has an insertion hole in its center through which the shaft base 20 can be inserted.

[0032] The strip-shaped portion of the rotor base 61a excluding the insertion holes is provided with magnetic pole core holding portions 61d into which the magnetic pole cores 61c fit. The magnetic pole core holding portions 61d are provided radially from the center point of the shaft base 20. A plurality of magnetic pole core holding portions 61d (26 in this embodiment, the same number as the magnetic pole cores 61c) are provided at intervals along the strip-shaped portion.

[0033] Each magnetic pole core holder 61d holds one magnetic pole core 61c. As shown in Fig. 6(b), the magnetic pole core 61c in this embodiment is a rectangular parallelepiped member made of laminated steel plates, which are made by stacking electromagnetic steel plates. Making the magnetic pole core 61c from laminated steel plates has the advantage of being easy to manufacture.

[0034] A jaw 61e that fits into the magnetic pole core holding portion 61d protrudes from the surface of the magnetic pole core 61c at one end in the longitudinal direction, facing the field coil 65b. The magnetic pole core 61c is fixed to the rotor base 61a with an adhesive or the like, with the jaw 61e fitted into the magnetic pole core holding portion 61d. Every other magnetic pole core 61c is attached in a different direction.

[0035] 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.

[0036] 2, the stator 62 is provided on the outer side of the shaft base 20 around the axis thereof and in a position 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.

[0037] The stator 62 of this embodiment includes a plurality of (24 in this embodiment) stator parts 62 a arranged in a ring shape. The stator parts 62 a here refer to the components (individual pieces) that make up the stator 62.

[0038] 7, the stator part 62a includes a stator core 62c and a concentrated winding stator coil 62d wound around the stator core 62c. In this embodiment, an E-shaped core is used as the stator core 62c, and copper windings are used as the stator coil 62d.

[0039] The stator core 62c is made of laminated steel plates, which are made by stacking electromagnetic steel plates. The laminated steel plates allow for easy manufacturing. The use of an E-shaped core makes the stator coil 62d less susceptible to damage during assembly and transportation, making assembly easier.

[0040] By using an E-shaped core as an outer core, the stator coil 62d can be surrounded and held against the electromagnetic force generated by slot leakage magnetic flux acting on the stator coil 62d, making it difficult for the stator coil 62d to move. This makes it possible to avoid the effects of coil vibration, such as a reduction in insulation life. Another advantage is that the heat dissipation surface can be increased, improving cooling performance. Note that a T-shaped core can also be used for the stator core 62c.

[0041] The exciter 65 is a member that excites the magnetic pole core 61c. As shown in Fig. 8(a), the exciter 65 of this embodiment includes a plurality of excitation cores 65a arranged in a ring shape and an annular field coil 65b provided along the plurality of excitation cores 65a.

[0042] As shown in Figure 8(b), the excitation core 65a can be a block core, but in this embodiment, it is a rectangular parallelepiped member that can be made from laminated steel plates by pressing steel plates. Using pressed laminated steel plates for the magnetic pole core 61c has the advantage of being easy to manufacture. The top surface of the excitation core 65a is provided with a recessed coil placement portion 65c in which the field coil 65b is placed.

[0043] The field coil 65b is a coil that excites the magnetic pole core 61c. In this embodiment, the field coil 65b is an annular coil that is wound to have a rectangular or approximately rectangular cross-sectional shape in which the thickness (axial) dimension is smaller than the width (radial) dimension.

[0044] The field coil 65b is disposed at a position spanning the coil arrangement portions 65c of the multiple excitation cores 65a arranged in a ring shape. The field coil 65b does not rotate but remains stationary within the coil arrangement portions 65c of the multiple excitation cores 65a.

[0045] The field coil 65b is arranged so that its bottom surface contacts the excitation core 65a, specifically, so that the bottom surface of the field coil 65b contacts the upper surface of the coil arrangement portion 65c of the excitation core 65a. The contact here includes not only direct contact between the two, but also indirect contact via adhesive, varnish, a thin insulating member made of thin-walled resin, etc.

[0046] By bringing a part of the field coil 65b (in the illustrated example, the bottom surface) into contact with the excitation core 65a, the heat generated in the field coil 65b is transferred with low thermal resistance over a large surface area (contact area).

[0047] This action improves the heat dissipation of the field coil 65b, lengthening the time constant for temperature rise, and making it easier to respond to the short-term maximum torque required to stop the motor quickly in the event of a malfunction or strong wind by passing a short-term maximum current through the field coil 65b. This effect is particularly necessary for wind power generation, and is an advantageous effect not available in conventional technology.

[0048] 9A, the stator part 62a and the excitation core 65a in this embodiment are unitized by being connected at one longitudinal end thereof by a connecting member (hereinafter referred to as "non-magnetic connecting member") 66 made of a non-magnetic material. The non-magnetic connecting member 66 can be fixed to the stator part 62a and the excitation core 65a with fasteners such as bolts so that it can be attached and detached.

[0049] Between the connected stator part 62a and the exciter core 65a, a space G is provided that is large enough to accommodate the thickness of the rotor 61. When the rotor 61 is fitted into this space G, as shown in Figure 9(b), a first air gap G1 is formed between the rotor 61 and the stator 62, and a second air gap G2 is secured between the rotor 61 and the exciter 65.

[0050] A support base 67 is provided around the axis of the shaft base 20 on the outer side thereof so as not to rotate together with the shaft base 20. The support base 67 (FIG. 2) in this embodiment is disk-shaped and has an insertion hole in its center through which the shaft base 20 can be inserted.

[0051] In the band-shaped portion of the support base 67 excluding the insertion holes, space is provided in which a U-shaped connected unit (hereinafter referred to as a "connecting unit") U including a stator part 62a, an excitation core 65a and a non-magnetic connecting member 66 can be arranged, and multiple connecting units U are arranged in a ring shape in the space.

[0052] The stator parts 62a in this embodiment can be individually removed and replaced by removing the non-magnetic connecting members 66. Specifically, as shown in Figures 10(a) and 10(b), the non-magnetic connecting members 66 are removed from the stator part 62a and the excitation core 65a, and then the stator part 62a is moved outward in the radial direction of the support base 67 (in other words, in a direction intersecting the axial direction of the shaft base 20), thereby allowing the stator part 62a to be removed.

[0053] In addition, the stator part 62a can be attached by first connecting it to a non-magnetic connecting member 66, then placing the stator part 62a above the magnetic pole core 61c, and then fixing the non-magnetic connecting member 66 to the excitation core 65a.

[0054] The procedure for attaching and removing the stator part 62a described here is an example, and the stator part 62a can also be attached and removed using procedures other than those described above.

[0055] <Operation of the power generating device of this embodiment> In the power generating device configured as described above, when a direct current is supplied to the field coil 65b, the magnetic pole core 61c is excited via the first air gap G1, and a magnetic circuit is formed between the excitation core 65a, the magnetic pole core 61c, and the stator part 62a, through which the magnetic flux generated by the excited field coil 65b passes.

[0056] 11, the magnetic flux generated by the excited field coil 65b passes from the excitation core 65a through the magnetic pole core 61c (referred to as the "first magnetic pole core 61x" for convenience of explanation), passes through the stator core 62c via the second air gap G2, and interlinks with the stator coil 62d. Here, because the magnetic pole cores 61c are arranged with a phase shift in the circumferential direction, the magnetic flux then changes position in the circumferential direction in the stator core 62c, passes through the magnetic pole core 61c (referred to as the "second magnetic pole core 61y" for convenience of explanation), and forms a magnetic circuit that takes a path that circumferentially returns to the excitation core 65a. The magnetic flux direction is reversed in the axial direction with a phase difference in the circumferential direction when entering the stator core 62c and when returning from the stator core 62c, and is excited to the north and south poles as viewed from the stator 62.

[0057] When the magnetic pole core 61c is excited and the rotary wind turbine 30 rotates in response to wind, the resulting rotational force rotates the shaft base 20, which in turn rotates the rotor 61 fixed to the shaft base 20. When the rotor 61 rotates, the torque of the magnetic pole core 61c is transmitted as a reaction to the stator core 62c due to the electromagnetic coupling between the magnetic pole core 61c and the stator 62 during power generation, and electricity is generated using this as power generating torque.

[0058] <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 when a specific configuration is provided, and are not necessarily effects that are always achieved by the power generating device of the present invention.

[0059] In this embodiment, the stator 62 is made up of individual stator parts 62a, which makes manufacturing easy. Furthermore, the stator parts 62a can be manufactured using conventional manufacturing equipment, which avoids the need for larger manufacturing equipment and the associated costs.

[0060] Furthermore, since the construction of the power generating device can be performed on individual stator parts 62a, there is no need for heavy-duty transport equipment or large-scale manufacturing equipment, and the increased costs associated with the introduction of such equipment can be avoided.

[0061] In this embodiment, the stator 62 is made up of stator parts 62a, and if one part is damaged, only the damaged stator part 62a needs to be replaced, which makes replacement easy and maintainable. Furthermore, the remaining stator parts 62a can continue to be used, which is economical.

[0062] In this embodiment, the magnetic pole core 61c is made of laminated steel plate, and the rotor base 61a that holds it is made of FRP, so that eddy currents generated by rotational magnetic flux fluctuations in the air gap that pass through the magnetic pole core 61c can be suppressed.

[0063] In this embodiment, a simple, circular coil is used as the field coil 65b, which eliminates the need to wind a field coil 65b for each magnetic pole, significantly reducing the number of steps required to manufacture the magnetic poles. In addition, the winding equipment for the field coil 65b can be simplified.

[0064] In this embodiment, a simple circular coil is used as the field coil 65b, so there is no need for a field coil winding 65b for each magnetic pole, and even large wind turbines with 100 to 200 field poles can be manufactured without excessive burden.

[0065] In this embodiment, the field coil 65b is stationary, and there is no need for a means for holding the field coil 65b against centrifugal force or for components (slip rings, brushes, etc.) that are required for a rotating field coil 65b, which simplifies the structure of the generator and improves maintainability. Improved maintainability is a particularly advantageous effect in direct drives, which are expected to be less prone to maintenance.

[0066] Furthermore, since the field coil 65b in this embodiment is stationary, the field coil 65b can be easily cooled.

[0067] In this embodiment, the stator coil 62d is a concentrated winding on an E-shaped core, and can be manufactured using the same manufacturing process as a normal transformer winding, making it easy to wind. In addition, there is no need to introduce new equipment, so there is no extra cost burden.

[0068] In this embodiment, the magnetic flux passage surface of the stator core 62c is aligned in the axial direction of the rotor 61, with one side facing the stator 62 and the other side facing the excitation core 65a. This allows the magnetic attraction forces generated in the magnetic pole core 61c to be offset above and below, thereby reducing the magnetic attraction force supported by the rotor base 61a that holds it and the required strength for the rotor base 61a, thereby making it possible to reduce the weight of the generator and the entire power generation device.

[0069] In this embodiment, a non-magnetic connecting member (non-magnetic connecting member 66) is used to connect the stator core 62c and the excitation core 65a, thereby preventing the magnetic flux of the excitation core 65a from bypassing the stator core 62c and reducing the magnetic flux controlled by the magnetic pole core 61c.

[0070] The power generation device of this embodiment uses a bearing module 50 that can be installed around the axis 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.

[0071] 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. Therefore, even if the shaft base 20 is deformed by external forces or its own weight, the air gaps (the first air gap G1 between the rotor 61 and the stator 62 and the second air gap G2 between the rotor 61 and the exciter 65) can easily be maintained at a predetermined width.

[0072] The power generation device of this embodiment has a gearless configuration, which eliminates the need for regular gear replacement, and therefore requires 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 (water-based) wind power generation device.

[0073] In this embodiment, the plurality of magnetic pole cores 61c are detachable from the rotor base 61a, and if one of the magnetic pole cores 61c is damaged, only the damaged magnetic pole core 61c needs to be replaced, which makes replacement easy and maintenance easy. In addition, the stator parts 62a other than the damaged stator part 62a can continue to be used, which is economical.

[0074] In a power generator using permanent magnets, there are issues such as large electromagnetic forces acting when the rotor and stator are joined and assembled, and a certain amount of iron loss occurs when the rotor rotates even when there is no load, which causes issues such as poor starting performance of the wind turbine at low loads and a deterioration in efficiency due to iron loss. However, the power generator of this embodiment does not have such issues.

[0075] In a power generation device using permanent magnets, when the blades themselves are used as flywheels to store energy in a grid-connected system, there is a problem that the iron loss of the magnetic flux generated by the permanent magnets reduces the rotation speed of the rotating wind turbine, resulting in a decrease in the amount of stored energy.However, the power generation device of this embodiment does not have this problem.

[0076] In a power generating device using a salient-pole field generator, a direct drive generator that is driven using fluid force has a large diameter and many poles, which increases the number of poles in the field winding, which causes problems such as an increase in field magnetomotive force and a significant increase in power supply, but such problems do not occur in the power generating device of this embodiment.

[0077] A generator made with a flat, large diameter has the problem that the axial length is short and the proportion of the coil ends at both ends of the axis of the field coil winding is relatively large compared to other rotating machines, resulting in large copper loss, but the power generation device of this embodiment does not have such problems.

[0078] <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.

[0079] In the above embodiment, an example is given in which the magnetic pole cores 61c are arranged in a ring shape on the rotor base 61a. However, as shown in Figures 12(a) and 12(b), the rotor base 61a may be configured such that the inner diameter and outer diameter are connected at a position surrounding the magnetic pole cores 61c in units of a multiple of two magnetic pole cores 61c (for example, one pole pair pitch, etc.), and cutout portions 61f that interrupt the current path may be provided at locations where a current path is formed that surrounds the magnetic pole cores 61c (61x, 61y) for one pole alone with respect to the axial magnetic flux.

[0080] By providing such cutouts 61f, the integral value of the magnetic flux passing through the loop of the pole component of the main magnetic flux between the cutouts 61f and its harmonic components can be set to zero, and as a result, eddy currents of the pole component that link with the rotor base 61a can be suppressed. When such cutouts 61f are provided, the rotor base 61a can be made of a metal material or the like.

[0081] Preferably, a non-magnetic insulating material such as FRP is embedded in the cutout 61f to form a composite with the metal, thereby preventing a decrease in strength and rigidity even when the cutout 61f is provided. Note that the same effect can be expected by providing a metal rib instead of the cutout 61f.

[0082] In the above embodiment, an example is given in which the number of magnetic pole cores 61c is 26 and the number of connecting units U (i.e., stator parts 62a, excitation cores 65a, and non-magnetic connecting members 66) is 24, but this number is just an example, and other combinations are also possible as long as the numbers of both are different.

[0083] 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).

[0084] 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 20 as shown in Fig. 13. In this case, it is preferable that the two or more generators 60 are arranged so that the magnetic forces of the rotors 61 of adjacent generators 60 cancel each other out.

[0085] 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.

[0086] 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 as shown in Fig. 14. The rotary wind turbine 30 may be a lift type or a drag type. Note that Fig. 14 shows a case where two generators 60 are provided in the axial direction of the shaft base 20, but the number of generators 60 may be more or less than two.

[0087] In the above embodiment, a floating wind power generation system in which the power generation system floats on water is used as an example, but the power generation system of the present invention can also be configured as an offshore (water-based) power generation system installed on water such as the ocean or a lake, or as a land-based power generation system installed on land.

[0088] In the above embodiment, the power generation device is a floating vertical axis type wind turbine power generation device as an example, but the power generation device can also be configured as a floating vertical axis type tidal power generator as shown in Figure 15.

[0089] The embodiments disclosed in this application are merely examples and are not intended to limit the technical 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.

[0090] The power generation device disclosed in the present application can be applied to various power generation devices, and in particular can be suitably used as a floating vertical axis type wind power generation device that floats on water such as the ocean or a lake.

[0091] REFERENCE SIGNS LIST 10 Floating body 20 Shaft base 30 Rotary wind turbine (force-receiving rotor) 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 61c Magnetic pole core 61d Magnetic pole core holding portion 61e Jaw portion 61f Cutout portion 61x First magnetic pole core 61y Second magnetic pole core 62 Stator 62a Stator part 62c Stator core 62d Stator coil 65 Exciter 65a Excitation core 65b Field coil 65c Coil arrangement portion 66 Non-magnetic connecting member 67 Support base 70 Mooring line G Space G1 First air gap G2 Second air gap U Connection unit

Claims

1. A power generating device comprising: a force-receiving rotor that rotates when subjected to fluid force; a shaft base that rotates in conjunction with the rotation of the force-receiving rotor; and a generator that generates electricity using the rotational force of the shaft base, wherein the generator comprises: a rotor arranged on the outer side of the shaft base around its axis so as to rotate together with the shaft base; a stator arranged on the outer side of the shaft base around its axis so as not to rotate together with the shaft base; and an exciter arranged on the outer side of the shaft base around its axis so as not to rotate together with the shaft base, wherein the rotor comprises a rotor base fixed to the shaft base and rotating together with the shaft base, and a plurality of magnetic pole cores arranged in a ring shape on the rotor base, and the exciter comprises an annular field coil that excites the magnetic pole cores.

2. The power generating device according to claim 1, wherein the rotor and the exciter are provided with a first air gap in the axial direction of the shaft base, and the rotor and the stator are provided with a second air gap in the axial direction of the shaft base.

3. The power generating device according to claim 2, wherein the stator comprises a plurality of stator parts arranged in an annular shape, the stator parts comprising a stator core and a stator coil wound around the stator core, a magnetic circuit passing through an excitation core, a magnetic pole core and the stator parts is formed by a magnetic field generated when a direct current is supplied to an annular field coil arranged coaxially with the shaft base, and the magnetic circuit is a path along which magnetic flux generated by the field coil passes from the excitation core through a first air gap to a first magnetic pole core, from the first magnetic pole core through a second air gap to pass through the stator parts and interlink with the stator coil wound around the stator core, then changes magnetic flux position circumferentially in the stator core, passes through a second magnetic pole core adjacent to the first magnetic pole core through the second air gap, and returns to the excitation core through the first air gap.

4. The power generating device according to claim 3, wherein the stator parts are individually replaceable by inserting and removing them in a direction intersecting the shaft base.

5. The power generating device according to claim 4, wherein the cross section of the field coil is rectangular or approximately rectangular, and the bottom surface of the field coil, which is in the direction of the longer side, is in contact with the excitation core.

6. The power generating device according to claim 1, wherein the plurality of magnetic pole cores are detachably held on the rotor base.

7. The power generating device according to claim 1, wherein the rotor base is made of a non-magnetic insulating material.

8. The power generating device according to claim 1, wherein the rotor base is provided with notches that interrupt the current path on the rotor base at any magnetic pole core pitch that is a multiple of two.

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