Wind propulsion device

Abstract

A wind propulsion device (1) according to an aspect of the present invention is installed on a movable body (2) and configured to generate propulsive force by receiving wind. The wind propulsion device (1) includes: a rotator (20) including a frame (21) having an annular shape around a rotation axis (RC), the rotator (20) being rotatable around the rotation axis; and a plurality of blades (10A-10I) provided such that imaginary straight lines connecting respective opposite ends in a direction orthogonal to the rotation axis (RC) are parallel, wherein the rotator (20) has a strut structure (25) including a plurality of struts (27) that are connected to the frame (21) and support the plurality of blades (10A-10I), respectively.

Description

TECHNICAL FIELD

[0001] The present invention relates to a wind propulsion device.BACKGROUND

[0002] Patent Literature 1 discloses a wind powered sailing ship equipped with vertical blades which are rotatable around a vertical shaft and configured in the form of a windmill.RELEVANT REFERENCE LIST OF RELEVANT PATENT LITERATURE

[0003] Patent Literature 1: Japanese Patent Application Publication No. Hei 6-199287SUMMARY

[0004] On the above sailing ship, a pillar may be installed in the central part in order to reduce the wobble of the rotation axis. If multiple blades are supported only by the central pillar to reduce weight, the rigidity will decrease.

[0005] The present invention is intended to overcome the above problem, and one object thereof is to provide a wind propulsion device having an increased rigidity.

[0006] To overcome the above problem, aspects of the present invention are configured as follows. (1) A wind propulsion device according to an aspect of the present invention is a wind propulsion device installed on a movable body and configured to generate propulsive force by receiving wind, the wind propulsion device comprising: a rotator including a frame having an annular shape around a rotation axis, the rotator being rotatable around the rotation axis; and a plurality of blades provided such that imaginary straight lines connecting respective opposite ends in a direction orthogonal to the rotation axis are parallel, wherein the rotator has a strut structure including a plurality of struts that are connected to the frame and support the plurality of blades, respectively.

[0007] According to this configuration, the plurality of blades are supported by the plurality of struts of the strut structure, thereby increasing the rigidity of the wind propulsion device compared to the case where the blades are supported only by the central pillar.

[0008] (2) In the wind propulsion device of (1) above, as viewed from an axial direction along the rotation axis, the strut structure may further include: a central pillar provided at a center of the frame; and a plurality of spokes extending radially from the central pillar and connected to the frame.

[0009] (3) In the wind propulsion device of (1) above, as viewed from an axial direction along the rotation axis, the strut structure may further include: a central pillar provided at a center of the frame; and a plurality of in-blade beams that extend radially outward from the central pillar and are connected at respective outer ends to the plurality of struts, the plurality of in-blade beams being provided in the plurality of blades, respectively.

[0010] (4) In the wind propulsion device of (1) above, the strut structure may have an inner space formed therein so as to communicate in an axial direction along the rotation axis, the plurality of struts may be arranged at equal intervals in a circumferential direction of the frame, the plurality of struts and the frame may be located within an imaginary cylinder around the rotation axis, and the plurality of blades may extend across the inner space and may be supported at respective opposite ends by the plurality of struts.

[0011] (5) In the wind propulsion device of (1) above, the strut structure may have an inner space formed therein so as to communicate in an axial direction along the rotation axis, the plurality of struts may be arranged at equal intervals in a radial direction of the frame, the plurality of struts and the frame may be located within an imaginary cylinder around the rotation axis, and the plurality of blades may extend across the inner space and may be supported at respective opposite ends by the plurality of struts.

[0012] (6) A wind propulsion device according to an aspect of the present invention is a wind propulsion device installed on a movable body and configured to generate propulsive force by receiving wind, the wind propulsion device comprising: a rotator including a frame having an annular shape around a rotation axis, the rotator being rotatable around the rotation axis; and a plurality of blades provided such that imaginary straight lines connecting respective opposite ends in a direction orthogonal to the rotation axis are parallel, wherein the plurality of blades include two blades provided in line symmetry with respect to a straight line including the rotation axis, and the ends of the two blades in an axial direction along the rotation axis form a trapezoid, as viewed from a direction parallel to the imaginary straight lines.

[0013] This configuration improves rigidity compared to the case where the axial ends of the two blades provided in line symmetry form a parallelogram when viewed from a direction parallel to the imaginary straight lines.

[0014] (7) In the wind propulsion device of (6) above, the rotator further may have a plurality of struts that are connected to the frame and support the plurality of blades, respectively, and as viewed from a direction parallel to the imaginary straight lines, two of the plurality of struts located on opposite outer sides with a center at the rotation axis may be provided along legs of a trapezoid.

[0015] (8) The wind propulsion device of any one of (1) to (7) above may comprise: at least one assembly each formed of the rotator and the plurality of blades, wherein the at least one assembly may each include a plurality of subassemblies that are arranged in a circumferential or radial direction of the frame and are detachably coupled to each other.

[0016] (9) In the wind propulsion device of (8) above, each of the plurality of subassemblies may include an upper frame member and a lower frame member, each formed in a semicircular shape as viewed in an axial direction along the rotation axis, and each of the plurality of blades may be connected at a top apex thereof to the upper frame member and at a bottom apex thereof to the lower frame member.

[0017] (10) In the wind propulsion device of (8) or (9) above, the plurality of subassemblies may comprise two subassemblies each having a semicircular shape as viewed in an axial direction along the rotation axis, the at least one assembly may comprise a plurality of assemblies arranged along the axial direction, and the plurality of assemblies may be stacked together such that respective two subassemblies are positioned differently in the circumferential direction and overlap as viewed from the axial direction.

[0018] (11) In the wind propulsion device of any one of (8) to (10) above, each of the plurality of subassemblies may include: an arc-shaped portion that constitutes the frame and is arc-shaped as viewed from an axial direction along the rotation axis; and a plurality of struts that are detachably connected to the arc-shaped portion.

[0019] (12) The wind propulsion device of any one of (1) to (11) above may comprise: a plurality of assemblies each formed of the rotator and the plurality of blades, wherein the plurality of assemblies may be arranged in an axial direction along the rotation axis, and wherein supposing that N is a number of assemblies and M is a natural number, the plurality of assemblies may be positioned differently from each other by 180×M / N degrees.

[0020] (13) In the wind propulsion device of (12) above, the plurality of blades may include two blades provided in line symmetry with respect to a straight line including the rotation axis, and the ends of the two blades in an axial direction along the rotation axis may form a trapezoid, as viewed from a direction parallel to the imaginary straight lines, and as viewed from a direction parallel to the imaginary straight lines, each of the plurality of assemblies may be disposed such that one end of the plurality of blades in the axial direction is connected to another end of blades in the axial direction which blades are shifted by one position inward or outward around the rotation axis.

[0021] (14) In the wind propulsion device of any one of (1) to (13) above, the plurality of blades may include two blades provided in line symmetry with respect to a straight line including the rotation axis, and the ends of the two blades in an axial direction along the rotation axis may form a trapezoid, as viewed from a direction parallel to the imaginary straight lines, and as viewed from a direction parallel to the imaginary straight lines, two of the plurality of assemblies that are adjacent to each other in the axial direction may be stacked together such that the respective plurality of blades are arranged along legs of trapezoids oriented in opposite directions.ADVANTAGEOUS EFFECTS

[0022] The present invention increases the rigidity.BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Fig. 1 is a perspective view showing a wind propulsion system according to a first embodiment. Fig. 2 is a diagram showing an example of functional configuration of the wind propulsion system according to the first embodiment. Fig. 3 is a diagram showing an example of flow of energy and the like in the wind propulsion system, along with a comparative example. Fig. 4 is a perspective view showing a rotor sail body in the wind propulsion device according to the first embodiment. Fig. 5 is a perspective view showing a wind propulsion device (wire-type) according to a second embodiment. Fig. 6 is a perspective view showing a wind propulsion device (spoke-type) according to a third embodiment. Fig. 7 is a perspective view showing a wind propulsion device (in-blade support type) according to a fourth embodiment. Fig. 8 is a perspective view showing a wind propulsion device (fully cylindrical type) according to a fifth embodiment. Fig. 9 is a perspective view showing a wind propulsion device (trapezoidal blades) according to a sixth embodiment. Fig. 10 is a schematic view showing trapezoidal struts of the wind propulsion device according to the sixth embodiment. Fig. 11 is a perspective view showing a divisional model of a wind propulsion device according to a seventh embodiment. Fig. 12 is a perspective view showing a subassembly of the wind propulsion device according to the seventh embodiment. Fig. 13 is a perspective view showing a wind propulsion device (semicircle-stacking type) according to an eighth embodiment. Fig. 14 is a perspective view showing an assembly of a wind propulsion device according to a ninth embodiment. Fig. 15 is a perspective view showing a subassembly of the wind propulsion device (strut type) according to the ninth embodiment. Fig. 16 is a schematic view showing a wind propulsion device (example 1 of vertical continuity) according to a tenth embodiment. Fig. 17 is a side view showing a plurality of assemblies of the wind propulsion device according to the tenth embodiment. Fig. 18 is a cross-sectional view showing a plurality of blades of the wind propulsion device according to the tenth embodiment. Fig. 19 is a schematic view showing a wind propulsion device (example 2 of vertical continuity) according to an eleventh embodiment. Fig. 20 is a side view showing a plurality of assemblies of the wind propulsion device according to the eleventh embodiment. Fig. 21 is a side view showing a wind propulsion device (combination of a strut structure and a central blade) according to a twelfth embodiment. Fig. 22 is a perspective view showing an assembly of the wind propulsion device according to the twelfth embodiment. Fig. 23 is a view showing a wind propulsion device (multiple stage stacking type) according to a thirteenth embodiment. Fig. 24 is a schematic view showing a wind propulsion device according to a first modification. Fig. 25 is a schematic view showing a wind propulsion device according to a second modification. Fig. 26 is a schematic view showing a wind propulsion device (model using steel material) according to a third modification. Fig. 27 is a schematic view showing a wind propulsion device (another example of fully cylindrical type) according to a fourth modification. DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Embodiments of a wind propulsion device and a wind propulsion system according to the present invention will now be described with reference to the accompanying drawings. In the following description, terms such as "parallel," "orthogonal," "center" and "coaxial" describe relative or absolute positions. These terms not only strictly mean such positions but also allow some tolerances and relative differences in angle and distance as long as the same effects can be still produced. In the drawings used for the following description, members are shown to different scales into recognizable sizes.<Wind Propulsion System>

[0025] Fig. 1 is a perspective view showing a wind propulsion system 100 according to a first embodiment. Fig. 2 is a diagram showing an example of functional configuration of the wind propulsion system 100 according to the first embodiment. Referring to Figs. 1 and 2 together, the wind propulsion system 100 includes a wind propulsion device 1, which is installed on a ship 2 (an example of a movable body) to generate propulsive force by receiving wind, and a rotor sail controller 140 (an example of a wind power controller) for controlling the wind propulsion device 1.

[0026] The wind propulsion device 1 includes a rotor sail body 111 that can rotate around a rotation axis RC (see Fig. 4) extending vertically from the hull 3. The wind propulsion device 1 further includes an electric motor 41 that rotates the rotor sail body 111. The rotor sail body 111 is equipped with an assembly 4 that includes a plurality of blades 10A to 10I that are connected together so as to be integrally rotatable around a rotation axis.

[0027] The wind propulsion device 1 includes a rotator 20, which has a frame 21 formed in an annular shape around the rotation axis RC and is rotatable around the rotation axis RC, and a plurality of blades 10A to 10I arranged such that imaginary straight lines connecting respective opposite ends of the blades in a direction orthogonal to the rotation axis RC are parallel (see Fig. 4). The rotator 20 has a strut structure 25 including a plurality of struts 26 to 28 that are connected to the frame 21 and support the plurality of blades 10A to 10I. The rotator 20 having the frame 21, and the plurality of blades 10A to 10I constitute the assembly 4.

[0028] The wind power controller 140 includes a speed meter 65 for acquiring the moving speed of the ship 2, a detection unit 7 for acquiring wind condition information including the current wind speed and wind direction in the area where the ship 2 is located, a calculation unit 126 for calculating the relative wind direction on the wind propulsion device 1 based on the acquired moving speed of the ship 2 and the wind condition information, and a rotation control unit 40 for controlling the electric motor 41 to adjust the rotation speed of the rotor sail body 111 according to the calculated relative wind direction. The wind propulsion device 1, which is included in the wind propulsion system 100, serves as a rotor sail that propels the ship 2 by generating a lift when receiving the wind.

[0029] The wind propulsion system 100 includes: the above-mentioned wind propulsion device 1 having the rotor sail body 111, the detection unit 7, a receiving unit 8, and the rotation control unit 40; a remote control device 120 equipped with an operation unit 121 that is operated to control a propulsion speed of the ship 2, and a determination unit 134 that determines a target thrust of the wind propulsion device 1 and a target thrust of a propeller 51 driven by a prime mover 50 attached to the ship 2 in accordance with an operation position of the operation unit 121; a rotor sail controller 140 that controls the rotational speed of the rotor sail body 111 rotating around the rotation axis in accordance with the target thrust of the wind propulsion device 1; and a prime mover controller 150 that controls a rotational speed of the prime mover 50 in accordance with the target thrust of the propeller 51. The wind propulsion system 100 constitutes a system (ship integrated propulsion system) that performs integrated control of two types of propulsion: propulsion by the wind propulsion device 1 and propulsion by the propeller 51 driven by the prime mover 50.

[0030] The ship 2 is equipped with the remote control device 120, the prime mover 50, a shaft 52, the propeller 51, a shaft horsepower meter 55, a detection system 60, the speed meter 65, and the prime mover controller 150. Note that the ship 2 is not necessarily a ship operated by crew members. For example, the ship 2 may be a ship capable of autonomous navigation.

[0031] The remote control device 120 executes a program (hereinafter referred to as a "ship control program") that controls the operation of the ship 2. The remote control device 120 functions, by executing the ship control program, as a device that includes a central control unit 130, the operation unit 121, a communication unit 122, an output unit 123, the calculation unit 126, and a storage unit 124. The remote control device 120 includes the central control unit 130 that controls operations of each functional unit of the remote control device 120.

[0032] The central control unit 130 includes, for example, a memory 132 and a processor 131 such as a CPU (Central Processing Unit) that are connected to each other via a bus. The processor 131 reads a ship control program stored in the storage unit 124 and stores the read ship control program in the memory 132. The processor 131 executes the ship control program stored in the memory 132.

[0033] The central control unit 130 communicates with the prime mover controller 150 by controlling the operation of the communication unit 122, for example. The central control unit 130 obtains information inputted via the operation unit 121, for example. The central control unit 130 records information generated by the execution of the ship control program in the storage unit 124, for example. The central control unit 130 obtains, for example, the number of revolutions of the prime mover 50. The central control unit 130 outputs, for example, the obtained number of revolutions to the prime mover controller 150. In the following description, an actual value of the number of revolutions of the prime mover 50 obtained (determined) by the central control unit 130 is also referred to as an "actual number of revolutions."

[0034] The operation unit 121 is a steering handle used to control both the speed and traveling direction of the ship 2. The operation unit 121 receives input from a crew. The crew inputs either one or both of a target number of revolutions or a rotational direction of an engine into the remote control device 120 by operating the operation unit 121. The target number of revolutions is a target number of revolutions of the prime mover 50. The rotational direction of the engine is the rotational direction of the prime mover 50. The rotational direction of the prime mover 50 is either forward or reverse. The traveling direction of the ship 2 with the prime mover 50 rotating in the forward direction is opposite to the traveling direction of the ship 2 with the prime mover 50 rotating in the reverse direction.

[0035] The operation unit 121 outputs the target number of revolutions indicated by the result of the crew's operation into the central control unit 130. The operation unit 121 outputs information indicating the engine rotational direction indicated by the result of the crew's operation (hereinafter referred to as "rotational direction information") to the central control unit 130. Note that the operation unit 121 does not necessarily need to be operated by crews. For example, when the ship 2 operates autonomously, the operation unit 121 may be operated by the central control unit 130 in accordance with a ship control program.

[0036] The communication unit 122 includes a communication interface for connecting the remote control device 120 to the shaft horsepower meter 55, the detection system 60, the speed meter 65, and the prime mover controller 150. The communication unit 122 communicates with the shaft horsepower meter 55, the detection system 60, the speed meter 65, and the prime mover controller 150 via either wired or wireless communication. The communication unit 122 transmits, for example, the target number of revolutions, the actual number of revolutions, and the rotational direction information to the prime mover controller 150.

[0037] The output unit 123 includes output devices such as display devices including CRT (Cathode Ray Tube) displays, liquid crystal displays, and organic EL (Electro-Luminescence) displays, as well as audio output devices such as speakers. The output unit 123 may be configured as an interface for connecting these output devices to the device in which the output unit is included. The output unit 123 outputs information related to the remote control device 120. The output unit 123 outputs, for example, results of operations performed via the operation unit 121.

[0038] The calculation unit 126 includes a processor such as a CPU (Central Processing Unit) (an example of a processing unit) connected by a bus. The calculation unit 126 calculates various information related to the remote control device 120. The calculation unit 126 calculates, for example, the relative wind direction on the wind propulsion device 1 based on the obtained traveling speed of the ship 2 and wind condition information.

[0039] The storage unit 124 is configured using storage devices such as magnetic hard disk devices and semiconductor storage devices. The storage unit 124 stores various information related to the remote control device 120. The storage unit 124 stores, for example, a ship control program in advance. The storage unit 124 stores information generated by execution of the ship control program, for example. The storage unit 124 stores, for example, a history of operations performed by crew members through the operation unit 121. The storage unit 124 stores, for example, a history of the actual number of revolutions of the prime mover 50.

[0040] The prime mover 50 is an engine that generates propulsive force for the ship 2. The prime mover 50 converts the energy contained in fuel into motive power. Any types of fuel and operating mechanism can be used provided that the prime mover 50 is able to convert the energy contained in fuel into the motive power. The prime mover 50 is, for example, a two-stroke diesel engine. Alternatively, the prime mover 50 may be, for example, a four-stroke diesel engine or a gas engine. For the sake of explanatory convenience, an example of the ship 2 in which the prime mover 50 is a two-stroke engine will be described.

[0041] The shaft 52 is rotated by the power produced by the prime mover 50. The number of rotations of the shaft 52 is proportional to the number of revolutions of the prime mover 50. The rotation of the shaft 52 transmits the power produced by the prime mover 50 to the propeller 51.

[0042] The propeller 51 is rotated by the power generated by the prime mover 50. The rotation of the propeller 51 produces the propulsive force that moves the ship 2.

[0043] The shaft horsepower meter 55 measures the power produced by the prime mover 50. The shaft horsepower meter 55 measures the power produced by the prime mover 50 by, for example, detecting a torsional strain produced in the shaft 52 by one or both of electrical and optical methods.

[0044] The detection system 60 includes a sensor that detects the number of revolutions of the prime mover 50. The detection system may include, for example, a proximity sensor. The proximity sensor may be configured to output an on-signal when metal is situated within a certain distance and an off-signal when the metal is not situated within the certain distance. In this case, the proximity sensor outputs an on signal when, for example, a convex portion provided on the surface of the shaft 52 is situated within a detection range and an off signal when a concave portion provided in the surface of the shaft 52 is situated within the detection range. The detection system 60 may detect the number of revolutions of the prime mover 50 based on such changes in the output of the proximity sensor and the information obtained in advance indicating the interval between the concave portion and convex portion of the shaft 52.

[0045] The detection system 60 may include other types of devices, in place of the proximity sensor. For example, the detection system 60 may include an encoder, a sensor that detects engine sound, or a sensor that detects engine vibration.

[0046] The speed meter 65 measures the speed of the ship 2. The speed meter 65 uses, for example, the Doppler effect for measuring the speed of the ship. The ship speed measured by the speed meter 65 is specifically the ship's speed relative to the water.

[0047] The prime mover controller 150 controls the operation of the prime mover 50. The prime mover controller 150 determines the amount of the fuel to be injected and the timing of the fuel injection based on the actual number of revolutions obtained by the determination unit 134. The prime mover controller 150 controls the operation of the prime mover 50 so that the determined amount of fuel is injected at the determined timing. The prime mover controller 150 controls the operation of the prime mover 50 by executing a fuel feed calculation process, fuel feed control process, and rotational direction control process.

[0048] In the fuel feed calculation process, the amount of fuel to be fed to the prime mover 50 (hereinafter also referred to as "fuel feed") is calculated based on the target number of revolutions and the actual number of revolutions, using a predetermined fuel feed calculation function. The fuel feed calculation function is a function that uses the target number of revolutions and the actual number of revolutions as explanatory variables, and the fuel feed as an objective variable. The prime mover controller 150 calculates the fuel feed by executing the fuel feed calculation process.

[0049] In the fuel feed control process, the degree of opening and closing of a valve attached to a fuel feed pipe is controlled so that the fuel feed calculated by the fuel feed calculation process is accomplished to the prime mover 50. The fuel feed pipe is a pipe connecting the prime mover 50 and an unshown fuel tank, through which the fuel flows from the fuel tank to the prime mover 50. The prime mover controller 150 feeds the fuel from the fuel tank to the prime mover 50 by executing the fuel feed control process.

[0050] In the rotational direction control process, the rotational direction of the prime mover 50 is controlled to the rotational direction of the engine. The rotational direction control process is, for example, a process of switching the rotation direction of the prime mover 50 between forward and reverse by operating a clutch of the prime mover 50. The prime mover controller 150 controls the rotational direction of the prime mover 50 to the rotational direction of the engine by executing the rotational direction control process.

[0051] The direction of a torque outputted by the prime mover 50 is in accordance with the rotational direction of the prime mover 50. Therefore, the direction of the torque occurring when the rotational direction of the prime mover 50 is forward is opposite to the direction of the torque occurring when the rotational direction of the prime mover 50 is reverse. The power produced by the prime mover 50 is equal to the value obtained by multiplying the magnitude of the torque outputted from the prime mover 50 by the number of revolutions of the prime mover 50.

[0052] The central control unit 130 is further provided with an obtaining unit 133 and the determination unit 134. The obtaining unit 133 obtains the results of detections performed by the detection system 60 via the communication unit 122. The determination unit 134 obtains the power measured by the shaft horsepower meter 55 via the communication unit 122. The obtaining unit 133 obtains the ship speed measured by the speed meter 65 via the communication unit 122. The obtaining unit 133 obtains the fuel feed calculated by the prime mover controller 150 via the communication unit 122. The obtaining unit 133 obtains the target number of revolutions and the rotational direction information outputted by the operation unit 121 via the communication unit 122.

[0053] The determination unit 134 executes a number-of-revolutions determination process. The number-of-revolutions determination process determines the actual number of revolutions of the prime mover 50 from one of values of the number of revolutions obtained by the detection system 60, based on at least one of the target number of revolutions, state information, which is information about the state of the prime mover 50, or the speed of the ship 2. Examples of the possible actual number of revolutions include a first number of revolutions and a second number of revolutions. The state information includes, for example, the fuel feed. The state information includes, for example, the power measured by the shaft horsepower meter 55.

[0054] The central control unit 130 outputs the actual number of revolutions determined by the determination unit 134 to the prime mover controller 150 via the communication unit 122. The central control unit 130 outputs the rotational direction information to the prime mover controller 150 via the communication unit 122. The central control unit 130 outputs the target number of revolutions to the prime mover controller 150 via the communication unit 122. The central control unit 130 controls the operation of the output unit 123 and causes the output unit 123 to output information.<Flow of Energy in Wind Propulsion System>

[0055] Fig. 3 is a diagram showing an example of flow of energy and the like in the wind propulsion system 100, along with a comparative example. In Fig. 3, the flow of physical objects, the flow of information, and the electrical flow (an example of a flow of energy and the like) are indicated by various arrows.

[0056] As shown in Fig. 3, in the comparative example (conventional system), the force of the wind is once converted to rotational force to turn the propeller. Therefore, in the comparative example, the force conversion results in a reduction of propulsion efficiency. In contrast, the wind propulsion system 100 of the embodiment has the rotor sail regarded as a propeller and uses directly as a propulsive force the lift (Magnus force) generated by the rotor sail rotating with the force of the wind. In other words, the wind propulsion system 100 of the embodiment uses the wind directly as a propulsive force. Therefore, the wind propulsion system 100 of the embodiment provides an improved propulsion efficiency compared to the comparative example.

[0057] Thus, in the wind propulsion system 100 of the embodiment, the wind is received by the rotor sail and converted into a propulsive force. For example, just as a sailing ship receives the wind in its sails and converts it into a propulsive force, a rotor sail ship converts the wind directly into a propulsive force with its rotor sail. The wind propulsion system 100 of the embodiment is characterized by converting the wind into a propulsive force as a sailing ship. In the wind propulsion system 100 of the embodiment, the performance of the rotor sail as a sail is superior to that of a conventional rigid-wing sail.<Electric Motor>

[0058] Referring to Figs. 2 to 4, the rotation control unit 40 includes an electric motor 41 capable of rotationally driving the rotor sail body 111. The electric motor 41 enables both the driving of the rotation of the rotor sail body 111 around a rotation axis and the acceleration and deceleration of the rotation of the rotor sail body 111. In other words, the electric motor 41 enables both the driving of the rotation of the blades 10A to 10H around the rotation axis and the acceleration and deceleration of the rotation of the blades 10A to 10H around the rotation axis.<Brake Unit>

[0059] The wind propulsion system 100 further includes a brake unit 45 that brakes the rotation of the blades 10A to 10H around the rotation axis when the wind speed exceeding a threshold is detected by the detection unit 7. The brake unit 45 reduces the rotation speed of the blades 10A to 10H by braking the rotation of the blades 10A to 10H around the rotation axis during strong winds, thereby reducing the lift. Induced drag can also be reduced by reducing lift during headwinds.<Energy Storage Unit>

[0060] The wind propulsion system 100 further includes an energy storage unit 46 that stores regenerative energy generated by the electric motor 41 when the rotation around the rotation axis is decelerated. With this configuration, it is possible to utilize the regenerative energy of the electric motor 41 stored in the energy storage unit 46. For example, the energy storage unit 46 may be configured to include a battery, capacitor, etc.

[0061] As described above, the rotor sail functions as a sail that converts the wind force into a propulsive force, and also operates as a generator capable of converting excess wind energy into electricity when the wind force exceeds propulsion commands. For example, the generated electricity may be used during propulsion or for general purposes such as lighting.<Obtaining Unit>

[0062] The wind propulsion system 100 further includes the obtaining unit 133 that obtains the wind speed and wind direction of the wind currently occurring. When the rotation speed of the blades 10A to 10H, which rotate only by the wind currently occurring, is below a threshold value, the rotation control unit 40 increases the rotation speed of the blades 10A to 10H rotating around the rotation axis, using the electric motor 41. For example, when the thrust that can be generated by the rotor sail rotating without energy supply based on the current wind speed and wind direction is insufficient to meet a thrust command, the thrust can be amplified by accelerating the rotation using the power of the electric motor 41.

[0063] For example, the threshold value for the rotational speed of the blades 10A to 10H (an example of a threshold value for the blade rotational speed) is calculated based on the thrust command. For example, the optimal rotational speed can be calculated from the thrust command, and based on that calculation result, the rotational speed of the blades 10A to 10H can be increased by the electric motor 41.<Relationship Between Rotor Sail Control And Prime Mover Control>

[0064] The thrust that the rotor sail ship can generate without auxiliary power is limited. Accordingly, any shortfall in the thrust occurring without auxiliary power may be compensated by the drive mode of the rotor sail (the rotational driving of the blades 10A to 10H). For example, any shortfall in the thrust occurring with the drive mode of the rotor sail may be compensated by the propeller 51 (propeller drive).

[0065] For example, the central control unit 130 calculates the optimal rotation speed of the blades 10A to 10H rotating around the rotation axis based on the received thrust command and the results of detection of the wind direction and wind speed conducted when the thrust command was received. For example, when controlling the rotational speed of the blades 10A to 10H, vector control can be used to control the q-axis current, enabling seamless control regardless of whether to drive or brake the blades. For example, the central control unit 130 may link the blades 10A to 10H and the propeller 51 and adjust the thrust ratio between the rotor sail and the propeller 51 to maximize energy efficiency.

[0066] As described above, the wind propulsion system 100 is a system that converts the wind force into thrust. For example, when a thrust command value is received from the remote control device 120, the optimal rotation speed of the blades 10A to 10H is calculated based on the wind direction and the wind speed so that the specified thrust is generated. Then, the electric motor 41 is controlled so that the calculated rotation speed is achieved. The rotation speed referred to here includes the direction of rotation. In the case of reverse rotation, the electric motor 41 is controlled at a negative speed.

[0067] For example, when the natural thrust of the rotor sail ship alone is insufficient, the propeller 51 is also driven. Depending on the wind direction, when the wind propulsion device 1 is more efficient than the propeller 51, the electric motor 41 is driven to increase the rotation speed and thus the thrust. On the other hand, when the propeller 51 is more efficient than the wind propulsion device 1, the wind propulsion device 1 is set to free operation mode, and the propeller 51 is driven to generate thrust. Additionally, it is also possible to drive both the electric motor 41 of the wind propulsion device 1 and the propeller 51.

[0068] For example, multiple rotor sails can be arranged on the hull to adjust the rotational moment of the ship. For example, multiple rotor sails can be arranged at the front and rear of the hull, and the rotational speeds can be made different between the front and rear rotor sails. This allows the forces acting in the lateral direction of the ship to be set to different values between the front and rear rotor sails, thereby generating a moment.<Steering Gear Control Unit>

[0069] Referring to Fig. 2, the wind propulsion system 100 further includes a steering gear control unit 125. When the rotation control unit 40 changes the rotational speed of the blades 10A to 10H around the rotation axis, the steering gear control unit 125 controls the steering gear to steer to a direction opposite to the inertial force generated in a direction opposite to the direction of changing the rotational speed of the blades 10A to 10H. By anticipating that the torque caused by the inertial force would impose on the hull 3, the steering gear control unit 125 cooperates with a rudder to counteract the torque and thus prevent the hull 3 from rotating.

[0070] For example, when changing the rotational speed of the blades 10A to 10H by driving or braking, it may cooperate with the rudder. For example, when the electric motor 41 is in a free state and the blades 10A to 10H are rotating freely, it may not be necessary to cooperate with the rudder. For example, when braking or driving to change the rotational speed of the blades 10A to 10H, torque may act on the hull 3, causing the hull 3 to rotate. To prevent this, when only one wind propulsion device 1 is installed, it is desirable to cooperate with the rudder to account for the torque acting on the hull 3, thereby preventing the hull 3 from rotating.<Wind Propulsion Device>

[0071] Referring to Figs. 1 and 2 together, the wind propulsion device 1 serves as a rotor sail which is installed on the ship 2 to generate propulsive force by receiving wind. In the illustrated example, a single wind propulsion device 1 is installed on the front part (bow) of the hull 3. The installation configuration (installation location, number of devices, etc.) of the wind propulsion device 1 is not limited to the above and can be modified in accordance with the design specifications.<Rotor Sail Body>

[0072] Fig. 4 is a perspective view showing a rotor sail body 111 in the wind propulsion device 1 according to the first embodiment. Referring to Fig. 4, the wind propulsion device 1 includes the rotor sail body 111 that can rotate around the rotation axis RC (represented by the chain line in Fig. 4) extending vertically from the hull 3. The rotor sail body 111 includes the assembly 4, which is constituted by the rotator 20 rotatable around the axis RC and a plurality of blades 10A to 10I each fixed to the rotator 20.

[0073] The rotator 20 has the frame 21 having an annular shape and located around the rotation axis RC and is rotatable around the rotation axis RC. In the illustrated example, the rotator 20 includes a lower frame 21, to which the lower ends of the plurality of blades 10A to 10I are fixed, and an upper frame 21, to which the upper ends of the plurality of blades 10A to 10I are fixed. The rotator 20 has a strut structure 25 including a plurality of struts 26 to 28 that are connected to the lower and upper frames 21 and support the plurality of blades 10A to 10I.

[0074] The plurality of blades 10A to 10I are each fixed to the frame 21 so that the imaginary straight lines connecting their respective opposite ends in a direction orthogonal to the rotation axis RC are parallel. The plurality of blades 10A to 10I include a central blade 10A. The imaginary straight line connecting the opposite ends of the central blade 10A passes through the center of the frame 21. The plurality of blades 10A to 10I are disposed so that their respective opposite ends are located on an imaginary circle around the rotation axis RC. The axial direction along the rotation axis RC is vertical.

[0075] Viewed from the vertical direction, those among the plurality of blades 10A to 10I that are disposed closer to the center of the frame 21 extend so that the length of the imaginary straight line is at least 1 / 2 the diameter of the frame 21. In the illustrated example, those among the plurality of blades 10A to 10I that are disposed closer to the center of the frame 21 are other than the outermost one of the plurality of blades 10A to 10I. The length of the imaginary straight line is the length from one end of the blade to the other, or what is called chord length. The outermost one of the plurality of blades 10A to 10I may have a chord length less than 1 / 2 the diameter of the frame 21 (an imaginary circle around the rotation axis RC). Note that the chord lengths of the plurality of blades 10A to 10I are not limited to the above and may be modified in accordance with the design specifications.

[0076] In the illustrated example, the frame 21 (an imaginary circle around the rotation axis RC) is a perfect circle as viewed from the vertical direction. Note that the shape of the imaginary circle as viewed from the vertical direction is not limited to the above, but may also be elliptical, oblong, or a closed ring formed by connecting curves.

[0077] As viewed from the vertical direction, the strut structure 25 has a central pillar 26 provided at the center of the frame 21, a pair of struts 27 provided at both ends of each imaginary straight line, and transverse struts 28 extending between both ends of each imaginary straight line. The central pillar 26, the pair of struts 27, and the upper and lower transverse struts 28 are made of metal, for example.

[0078] The rotator 20 further includes a rod-shaped beam 22 (horizontal rod) that is connected at both ends thereof to the inner circumference of the frame 21 and that connects the plurality of blades 10A to 10I together. In the illustrated example, the beam 22 passes through the center of the frame 21 and is connected at both ends thereof to the inner circumference of the frame 21. The rotator 20 has two beams 20, one each for the upper and lower frames 21. Note that the configuration (number and arrangement, etc.) of the beams 22 is not limited to the above and can be modified in accordance with the design specifications.

[0079] In the illustrated example, the central pillar 26 has a cylindrical shape. Each of the pair of struts 27 has a cylindrical shape with a smaller diameter than the central pillar 26. The pair of struts 27 have the same shape. The transverse strut 28 that supports the central blade 10A has a diamond shape as viewed from the vertical direction. The transverse struts 28 that support the blades 10B to 10I other than the central blade 10A are I-shaped (straight) as viewed from the vertical direction. Note that the struts supporting the plurality of blades 10A to 10I, including the central blade 10A, may be I-shaped (straight) as viewed from the vertical direction. The configuration (number, geometry, shape, etc.) of the struts supporting the plurality of blades 10A to 10I, including the central blade 10A, is not limited to the above and may be modified in accordance with the design specifications.

[0080] The central blade 10A is disposed such that the imaginary straight line connecting the opposite ends of the central blade 10A passes through the center of the frame 21. In the illustrated example, the central blade 10A is formed of fabric stretched over the central pillar 26, the pair of struts 27, and the upper and lower transverse struts 28. The blades 10B to 10I, other than the central blade 10A, are formed of fabric stretched over the pair of struts 27 and the upper and lower transverse struts 28. It is also possible that the blades 10B to 10I other than the central blade 10A are formed of fabric, and only the central blade 10A is formed of FRP (resin). For example, at least one of the plurality of blades 10A to 10I may be made of fabric, and the other blades may be made of resin.

[0081] In the example shown in Fig. 4, the assembly 4 has a single stage; however, this embodiment is not limited thereto, and the number of stages of the assembly 4 can be modified in accordance with the design specifications. In the example shown in Fig. 1, there are multiple (e.g., three) assemblies 4A to 4C provided along the vertical direction. For example, if assemblies 4A and 4B are provided, the assemblies 4A and 4B may have a common rotator 20. The installation configuration of the rotator 20 with respect to a plurality of assemblies 4 may be varied in accordance with the design specifications. Furthermore, the assemblies 4A and 4B may have the same shape, and the rotator 20 may be bolted or welded.

[0082] Each of the plurality of blades 10A to 10I may have a twisted shape such that a first imaginary straight line, which connects both ends of the blade at a first position on the rotation axis RC (represented by the chain line in the drawing), and a second imaginary straight line, which connects both ends of the blade at a second position on the rotation axis RC different from the first position, intersect with each other when viewed in the vertical direction. In other words, each of the plurality of blades 10A to 10I may have a twisted shape such that cross-sections thereof orthogonal to the vertical direction are the same at any position on the rotation axis. It should be noted that the manner of twisting (such as the shape) of the plurality of blades is not limited to the above and may be modified in accordance with the design specifications.<Advantageous Effects>

[0083] As described above, the wind propulsion device 1 according to this embodiment is installed on the hull 2 and generates propulsive force by receiving wind. The wind propulsion device 1 includes a rotator 20, which has a frame 21 formed in an annular shape around the rotation axis RC and is rotatable around the rotation axis RC, and a plurality of blades 10A to 10I arranged such that an imaginary straight line connecting both ends of each blade in a direction orthogonal to the rotation axis RC is parallel. The rotator 20 has a strut structure 25 including a plurality of struts 26 to 28 that are connected to the frame 21 and support the plurality of blades 10A to 10I.

[0084] According to this configuration, the plurality of blades 10A to 10I are supported by the plurality of struts 26 to 28 of the strut structure 25, thereby increasing the rigidity of the wind propulsion device 1 compared to the case where the blades are supported only by the central pillar. The increased rigidity produces the following advantageous effects (1) and (2). (1) Increased strength and reduced stress on the components. (2) Higher natural resonance frequency and reduced likelihood of resonance caused by rotation. <Second Embodiment>

[0085] The following describes a wind propulsion device 201 (wire-type) according to a second embodiment. In the following description, the parts having the same functions as in the first embodiment will have the same names and reference numerals, and their functions will not be specifically described.

[0086] Fig. 5 is a perspective view showing a wind propulsion device 201 (wire-type) according to the second embodiment. As shown in Fig. 5, in the wind propulsion device 201 of the second embodiment, the strut structure 225 includes a plurality of wires 227, 228 (tension structure) that are connected to the frame 21 and support the plurality of blades 10A to 10I. As viewed from the vertical direction, the strut structure 225 has a central pillar 26 provided at the center of the frame 21, a pair of longitudinal wires 227 provided at both ends of each imaginary straight line, and transverse wires 228 extending between both ends of each imaginary straight line. The pair of longitudinal wires 227 and the upper and lower transverse wires 228 are made of metal, for example. The central blade 10A is formed of fabric stretched over the central pillar 26, the pair of longitudinal wires 227, and the upper and lower transverse wires 228. The blades 10B to 10I, other than the central blade 10A, are formed of fabric stretched over the pair of longitudinal wires 227 and the upper and lower transverse wires 228.

[0087] In the example shown in Fig. 5, the shape formed by combining the central pillar 26 and the transverse wires 228 in the strut structure 225 is a q-shape when viewed from the vertical direction. The plurality of wires 227 and 228 are formed as linear members having a smaller diameter than the struts 27 of the first embodiment. The fabric of the central blade 10A has a diamond shape as viewed from the vertical direction. The plurality of wires 227, 228 may each penetrate a portion (edge) of the plurality of blades 10A to 10I. Note that the configuration (number, geometry, shape, etc.) of the plurality of wires 227, 228 included in the strut structure 225 is not limited to the above and can be modified in accordance with the design specifications.

[0088] The strut structure 225 according to this embodiment includes a plurality of wires 227, 228 that are connected to the frame 21 and support the plurality of blades 10A to 10I. According to this configuration, compared to the case where the plurality of blades 10A to 10I are supported by struts, the structure can be more lightweight and more aerodynamically advantageous.<Third Embodiment>

[0089] The following describes a wind propulsion device 301 (spoke-type) according to a third embodiment. In the following description, the parts having the same functions as in the first embodiment will have the same names and reference numerals, and their functions will not be specifically described.

[0090] Fig. 6 is a perspective view showing a wind propulsion device 301 (spoke-type) according to the third embodiment. Fig. 6 does not show the upper frame 21. As shown in Fig. 6, in the wind propulsion device 301 of the third embodiment, the strut structure 325 further includes the central pillar 26 provided at the center of the frame 21 as viewed in the axial direction along the rotation axis RC, and a plurality of spokes 328 that extend radially from the central pillar 26 and are connected to the frame 21.

[0091] In the example shown in Fig. 6, each of the plurality of spokes 328 is shaped like a circular column. Each of the plurality of spokes 328 has the same shape. The plurality of spokes 328 are in radial arrangement in which circular columns of the same length extending from the central pillar 26 are at equal intervals in the circumferential direction when viewed from the vertical direction. The plurality of spokes 328 are each connected at one end to the central pillar 26 and at the other end to the strut 27 via the frame 21. Note that the configuration (number, geometry, shape, connection relationship, etc.) of the spokes 328 is not limited to the above and can be modified in accordance with the design specifications.

[0092] The strut structure 325 according to this embodiment further includes the central pillar 26 provided at the center of the frame 21 as viewed in the axial direction along the rotation axis RC, and a plurality of spokes 328 that extend radially from the central pillar 26 and are connected to the frame 21. This configuration improves rigidity compared to the case without the central pillar 26 and the plurality of spokes 328 (fully cylindrical type).<Fourth Embodiment>

[0093] The following describes a wind propulsion device 401 (in-blade support type) according to a fourth embodiment. In the following description, the parts having the same functions as in the first embodiment will have the same names and reference numerals, and their functions will not be specifically described.

[0094] Fig. 7 is a perspective view showing a wind propulsion device 401 (in-blade support type) according to the fourth embodiment. As shown in Fig. 7, in the wind propulsion device 401 of the fourth embodiment, the strut structure 425 further includes the central pillar 26 provided at the center of the frame 21 as viewed in the axial direction along the rotation axis RC, and a plurality of in-blade beams 429 that extend radially outward from the central pillar 26 and are connected at respective outer ends to the struts 27 and provided in the plurality of blades 10A to 10I.

[0095] In the example shown in Fig. 7, the plurality of in-blade beams 429 include two beams that extend radially outward from the central pillar 26 and intersect each other at respective middle portions. One of the in-blade beams 429 extends from the upper end of the central pillar 26 (the radially inner end of the upper transverse strut 28) radially outward and vertically downward, and its outer end is connected to the radially outer end of the lower transverse strut 28 (the lower end of the strut 27 via the frame 21). The other of the in-blade beams 429 extends from the lower end of the central pillar 26 (the radially inner end of the lower transverse strut 28) radially outward and vertically upward, and its outer end is connected to the radially outer end of the upper transverse strut 28 (the upper end of the strut 27 via the frame 21). Note that the configuration (number, geometry, shape, connection relationship, etc.) of the in-blade beams 429 is not limited to the above and can be modified in accordance with the design specifications.

[0096] The strut structure 425 according to this embodiment further includes the central pillar 26 provided at the center of the frame 21 as viewed in the axial direction along the rotation axis RC, and a plurality of in-blade beams 429 that extend radially outward from the central pillar 26 and are connected at respective outer ends to the struts 27 and provided in the plurality of blades 10A to 10I. This configuration improves rigidity compared to the case without the central pillar 26 and the plurality of in-blade beams 429 (fully cylindrical type).<Fifth Embodiment>

[0097] The following describes a wind propulsion device 501 (fully cylindrical type) according to a fifth embodiment. In the following description, the parts having the same functions as in the first embodiment will have the same names and reference numerals, and their functions will not be specifically described.

[0098] Fig. 8 is a perspective view showing a wind propulsion device 501 (fully cylindrical type) according to the fifth embodiment. Fig. 8 does not show the upper frame 21. As shown in Fig. 8, in the wind propulsion device 501 of the fifth embodiment, the strut structure 525 has an inner space 525S formed therein so as to communicate in the axial direction along the rotation axis RC. The plurality of struts 27 are arranged at equal intervals in the circumferential direction of the frame 21. The plurality of struts 27 and the frame 21 are located within an imaginary cylinder around the rotation axis RC. The plurality of blades 10A to 10I extend across the inner space 525S and are supported at respective opposite ends by the plurality of struts 27.

[0099] In the example shown in Fig. 8, the inner space 525S does not contain the central pillar 26. The central blade 10A, which extends across the inner space 525S, has a rhombic shape as viewed from the vertical direction. The blades 10B to 10I other than the central blade 10A are I-shaped (straight) as viewed from the vertical direction. Note that the configuration (number, geometry, shape, etc.) of the plurality of blades 10A to 10I, including the central blade 10A, is not limited to the above and may be modified in accordance with the design specifications.

[0100] The strut structure 525 according to this embodiment has the inner space 525S formed therein so as to communicate in the axial direction along the rotation axis RC. The plurality of struts 27 are arranged at equal intervals in the circumferential direction of the frame 21. The plurality of struts 27 and the frame 21 are located within an imaginary cylinder around the rotation axis RC. The plurality of blades 10A to 10I extend across the inner space 525S and are supported at respective opposite ends by the plurality of struts 27. This configuration reduces manufacturing costs compared to the case with the central pillar 26 (spoke type and in-blade support type).<Sixth Embodiment>

[0101] The following describes a wind propulsion device 601 (trapezoidal blades) according to a sixth embodiment. In the following description, the parts having the same functions as in the first embodiment will have the same names and reference numerals, and their functions will not be specifically described.

[0102] Fig. 9 is a perspective view showing a wind propulsion device 601 (trapezoidal blades) according to the sixth embodiment. Fig. 9 does not show components such as the rotator 20 having the frame 21. Fig. 10 is a schematic view showing trapezoidal struts of the wind propulsion device 601 according to the sixth embodiment. Fig. 10 does not show the plurality of blades 610A to 610G. Referring to Figs. 9 and 10 together, in the wind propulsion device 601 of the sixth embodiment, the plurality of blades 610A to 610G include two blades provided in line symmetry with respect to the straight line including the rotation axis RC. The ends of these two blades in the axial direction along the rotation axis RC form a trapezoid, as viewed from the direction parallel to the imaginary straight lines.

[0103] In the example shown in Fig. 9, two blades provided in line symmetry with respect to the straight line including the rotation axis RC (i.e., two blades other than the central blade 610A, namely the blades 610B and 610G, 610C and 610F, and 610D and 610E) are each formed in a twisted shape such that the positional relationship of their ends in the vertical direction is not parallel, as viewed in the direction perpendicular to the vertical line. Note that the configuration (number, shape, etc.) of the plurality of blades 610A to 610G is not limited to the above and may be modified in accordance with the design specifications.

[0104] The rotator 20 has the plurality of struts 27 that are connected to the frame 21 and support the plurality of blades 610A to 610G. When viewed from a direction parallel to the imaginary straight lines, two of the plurality of struts 27 located on opposite outer sides with the center at the rotation axis RC are provided along the legs of the trapezoid.

[0105] Fig. 10 is an example of a two-dimensional representation of the configuration in Fig. 9. Ordinary parallel blades have a twist, but the blades are nearly parallel to each other. The trapezoidal blades are formed of twisted parallel blades and are fixed obliquely as shown in Fig. 10.

[0106] In the wind propulsion device 601 according to this embodiment, the plurality of blades 610A to 610G include two blades provided in line symmetry with respect to the straight line including the rotation axis RC. The ends of these two blades in the axial direction along the rotation axis RC form a trapezoid, as viewed from the direction parallel to the imaginary straight lines. This configuration improves rigidity compared to the case where the axial ends of the two blades provided in line symmetry form a parallelogram when viewed from a direction parallel to the imaginary straight lines.

[0107] The rotator 20 according to this embodiment has the plurality of struts 27 that are connected to the frame 21 and support the plurality of blades 610A to 610G, respectively. When viewed from a direction parallel to the imaginary straight lines, two of the plurality of struts 27 located on opposite outer sides with the center at the rotation axis RC are provided along the legs of the trapezoid. This configuration improves rigidity compared to the case where two struts 27 located on opposite outer sides are parallel to each other.<Seventh Embodiment>

[0108] The following describes a wind propulsion device 701 (divisional model) according to a seventh embodiment. In the following description, the parts having the same functions as in the first embodiment will have the same names and reference numerals, and their functions will not be specifically described.

[0109] Fig. 11 is a perspective view showing a divisional model of a wind propulsion device 701 according to the seventh embodiment. Fig. 12 is a perspective view showing a subassembly 770 of the wind propulsion device 701 according to the seventh embodiment. Referring to Figs. 11 and 12 together, the wind propulsion device 701 of the seventh embodiment includes assemblies 704A to 704C each formed of a rotator 20 and a plurality of blades 710A to 710E. The assemblies 704A to 704C each include a plurality of subassemblies 770 that are arranged in the circumferential or radial direction of the frame 21 and are detachably coupled to each other.

[0110] In the example shown in Fig. 11, each of the assemblies 704A to 704C includes two subassemblies 770 that are arranged in the circumferential and radial directions of the frame 12 and are detachably coupled to each other. The two subassemblies 770 have the same shape. One of the two subassemblies 770 in one assembly 704B is not shown. Note that the configuration (number, shape, etc.) of the plurality of subassemblies 770 is not limited to the above and may be modified in accordance with the design specifications.

[0111] Each of the subassemblies 770 includes an upper frame member 771 and a lower frame member 772, which are each formed in a semicircular shape when viewed in the axial direction along the rotation axis RC. Each of the plurality of blades 710A to 710E is connected at the top apex thereof to the upper frame member 771 and at the bottom apex thereof to the lower frame member 772.

[0112] For example, the upper frame member 771 and the lower frame member 772 are made of metal. The plurality of blades 710A to 710E are made of GFRP (Glass Fiber Reinforced Plastics), for example. The upper frame member 771 and the lower frame member 772 have a plurality of grooves for fitting the blades 710A to 710E in their respective opposing parts. Each of the plurality of blades 710A to 710E is fitted at the top apex thereof into the grooves in the upper frame member 771 and at the bottom apex thereof into the grooves in the lower frame member 772. The blades 710A to 710E may be made of wood, other resins, or a composite of wood and resin. The blades 710A to 710E may be bolted or welded. Note that the configuration (material, shape, connection relationship, etc.) of the upper frame member 771, the lower frame member 772, and the plurality of blades 710A to 710E is not limited to the above and may be modified in accordance with the design specifications.

[0113] The wind propulsion device 701 according to this embodiment includes assemblies 704A to 704C each formed of a rotator 20 and a plurality of blades 710A to 710E. The assemblies 704A to 704C each include a plurality of subassemblies 770 that are arranged in the circumferential or radial direction of the frame 21 and are detachably coupled to each other. According to this configuration, the assemblies 704A to 704C can be divided into a plurality of subassemblies 770, and thus transportation costs are reduced compared to the case where the assemblies cannot be divided.

[0114] Each of the subassemblies 770 according to this embodiment includes an upper frame member 771 and a lower frame member 772, which are each formed in a semicircular shape when viewed in the axial direction along the rotation axis RC. Each of the plurality of blades 710A to 710E is connected at the top apex thereof to the upper frame member 771 and at the bottom apex thereof to the lower frame member 772. According to this configuration, each of the subassemblies 770 can be divided into the upper frame member 771, the lower frame member 772, and the plurality of blades 710A to 710E, and thus transportation costs are reduced compared to the case where the subassemblies cannot be divided. For example, a divided subassembly 770 can be transported by sea without the need for a dedicated vessel.<Eighth Embodiment>

[0115] The following describes a wind propulsion device 801 (semicircle-stacking type) according to an eighth embodiment. In the following description, the parts having the same functions as in the seventh embodiment will have the same names and reference numerals, and their functions will not be specifically described.

[0116] Fig. 13 is a perspective view showing a wind propulsion device 801 (semicircle-stacking type) according to the eighth embodiment. As shown in Fig. 13, in the wind propulsion device 801 of the eighth embodiment, the plurality of subassemblies 870A, 870B are constituted by two subassemblies 870A, 870B each having a semicircular shape when viewed in the axial direction along the rotation axis RC. A plurality of assemblies 804A to 804D are arranged in the axial direction. The plurality of assemblies 804A to 804D are stacked together such that respective two subassemblies 870A, 870B are positioned differently in the circumferential direction and overlap when viewed from the axial direction.

[0117] In the example shown in Fig. 13, the central blade 810A is divided in the radial direction. One and the other of the subassemblies 870A and 870B constituting the second-lowest assembly 804B are stacked on one and the other of the two subassemblies 870A and 870B constituting the lowermost assembly 804A so as to be positioned differently in the circumferential direction and overlap when viewed from the axial direction. The plurality of subassemblies 870A and 870B, including the divided central blade 810A, are joined together such that the curves are aerodynamically smoothly connected. One of the subassemblies, denoted as 870B, in the second-lowest assembly 804B is not shown. Note that the configuration (number, shape, connection relationship, etc.) of the plurality of subassemblies 870A, 870B is not limited to the above and may be modified in accordance with the design specifications.

[0118] The plurality of subassemblies 870A, 870B according to this embodiment are constituted by two subassemblies 870A, 870B each having a semicircular shape when viewed in the axial direction along the rotation axis RC. A plurality of assemblies 804A to 804D are arranged in the axial direction. The plurality of assemblies 804A to 804D are stacked together such that respective two subassemblies 870A, 870B are positioned differently in the circumferential direction and overlap when viewed from the axial direction. According to this configuration, the subassemblies 870A and 870B are less likely to separate as compared to the case where the respective two subassemblies 870A and 870B of the plurality of assemblies 804A to 804D are stacked without being positioned differently in the circumferential direction.<Ninth Embodiment>

[0119] The following describes a wind propulsion device 901 (model using steel material) according to a ninth embodiment. In the following description, the parts having the same functions as in the first embodiment will have the same names and reference numerals, and their functions will not be specifically described.

[0120] Fig. 14 is a perspective view showing a wind propulsion device 901 (model using steel material) according to the ninth embodiment. Fig. 15 is a perspective view showing a subassembly 970 of the wind propulsion device 901 (strut type) according to the ninth embodiment. Referring to Figs. 14 and 15 together, each of the plurality of subassemblies 970 includes an arc-shaped portion 971 that constitutes the frame 21 and is arc-shaped as viewed from the axial direction along the rotation axis RC, and a plurality of struts 927, 928 that are detachably connected to the arc-shaped portion 971.

[0121] In the example shown in Fig. 14, each assembly includes three subassemblies 970. The frame 21 is divided in the circumferential direction into three, each forming the arc-shaped portion 971 for one subassembly 970. Six each of struts 927 and struts 928 are provided for each subassembly 970. The subassemblies 970 each include an arc-shaped connecting member 972 that connects portions (the longitudinally middle portions) of the plurality of struts 928 to each other. Note that the configuration (number, geometry, connection relationship, etc.) of the plurality of subassemblies 970 is not limited to the above and may be modified in accordance with the design specifications.

[0122] Each of the plurality of subassemblies 970 includes an arc-shaped portion 971 that constitutes the frame and is arc-shaped as viewed from the axial direction along the rotation axis, and a plurality of struts 927, 928 that are detachably connected to the arc-shaped portion 971. According to this configuration, each of the subassemblies 970 can be divided into the arc-shaped portion 971 and the plurality of struts 927, 928, and thus transportation costs are reduced compared to the case where the subassemblies cannot be divided.<Tenth Embodiment>

[0123] The following describes a wind propulsion device 1001 (example 1 of vertical continuity) according to a tenth embodiment. In the following description, the parts having the same functions as in the first embodiment will have the same names and reference numerals, and their functions will not be specifically described.

[0124] Fig. 16 is a schematic view showing a wind propulsion device 1001 (example 1 of vertical continuity) according to the tenth embodiment. Fig. 17 is a side view showing a plurality of assemblies 1004A to 1004D of the wind propulsion device 1001 according to the tenth embodiment. Fig. 18 is a cross-sectional view showing a plurality of blades 1010A to 1010G of the wind propulsion device 1001 according to the tenth embodiment. Referring to Figs. 16 to 18 together, in the wind propulsion device 1001 of the tenth embodiment, the plurality of blades 1010A to 1010G include two blades provided in line symmetry with respect to the straight line including the rotation axis RC. The ends of these two blades in the axial direction along the rotation axis RC form a trapezoid, as viewed from the direction parallel to the imaginary straight lines. When viewed from a direction parallel to the imaginary straight lines, each of the plurality of assemblies 1004A to 1004D is disposed as follows: one axial end of the plurality of blades 1010B to 1010G is connected to the other axial end of the blades 1010B to 1010G that are shifted by one position inward or outward around the rotation axis RC.

[0125] In the example shown in Fig. 16, when viewed from a direction parallel to the imaginary straight lines, the vertically upper ends of the two blades 1010B and 1010G, and 1010C and 1010F on both outer sides, included in the lowermost assembly 1004A, are coupled to the vertically lower ends of the two blades 1010C and 1010F, and 1010D and 1010E on both inner sides (blades shifted by one position inward around the rotation axis RC), included in the second-lowest assembly 1004B. Similarly, the vertically upper ends of the two blades 1010B and 1010G, and 1010C and 1010F on both outer sides, included in the second-lowest assembly 1004B, are coupled to the vertically lower ends of the two blades 1010C and 1010F, and 1010D and 1010E on both inner sides (blades shifted by one position inward around the rotation axis RC), included in the third-lowest assembly 1004C. Similarly, the vertically upper ends of the two blades on both outer sides, included in the third-lowest assembly 1004C, are coupled to the vertically lower ends of the two blades on both inner sides, included in the fourth-lowest (uppermost) assembly 1004D. Note that the configuration (number, coupling relationship, etc.) of the plurality of assemblies 1004A to 1004D is not limited to the above and may be modified in accordance with the design specifications.

[0126] In the wind propulsion device 1001 according to this embodiment, the plurality of blades 1010A to 1010G include two blades 1010A to 1010G provided in line symmetry with respect to the straight line including the rotation axis RC. The ends of these two blades in the axial direction along the rotation axis RC form a trapezoid, as viewed from the direction parallel to the imaginary straight lines. When viewed from a direction parallel to the imaginary straight lines, each of the plurality of assemblies 1004A to 1004D is disposed as follows: one axial end of the plurality of blades 1010B to 1010G is connected to the other axial end of the blades 1010B to 1010G that are shifted by one position inward or outward around the rotation axis RC. According to this configuration, the plurality of blades 1010B to 1010G can be smoothly coupled to those shifted by one position between each of the plurality of assemblies 1004A to 1004D, and thus the air flow is not disturbed.<Eleventh Embodiment>

[0127] The following describes a wind propulsion device 1101 (example 2 of vertical continuity) according to an eleventh embodiment. In the following description, the parts having the same functions as in the tenth embodiment will have the same names and reference numerals, and their functions will not be specifically described.

[0128] Fig. 19 is a schematic view showing a wind propulsion device 1101 (example 2 of vertical continuity) according to the eleventh embodiment. Fig. 20 is a side view showing a plurality of assemblies of the wind propulsion device 1101 according to the eleventh embodiment. Referring to Figs. 19 and 20 together, in the wind propulsion device 1101 of the eleventh embodiment, the plurality of blades 1110A to 1110G include two blades provided in line symmetry with respect to the straight line including the rotation axis RC. The ends of these two blades in the axial direction along the rotation axis RC form a trapezoid, as viewed from the direction parallel to the imaginary straight lines. When viewed from a direction parallel to the imaginary straight lines, axially adjacent two of the plurality of assemblies 1104A to 1104D are stacked together so that their respective blades 1110B to 1110G are arranged along the legs of trapezoids oriented in opposite directions.

[0129] In the example shown in Fig. 19, when viewed from a direction parallel to the imaginary straight lines, the lowermost assembly 1104A and the second-lowest assembly 1104B are stacked together so that their respective blades 1110B to 1110G are arranged along the legs of trapezoids oriented in opposite directions. Similarly, the second-lowest assembly 1104B and the third-lowest assembly 1104C are stacked together so that their respective blades 1110B to 1110G are arranged along the legs of trapezoids oriented in opposite directions. Similarly, the third-lowest assembly 1104C and the fourth-lowest (uppermost) assembly 1104D are stacked together so that their respective blades are arranged along the legs of trapezoids oriented in opposite directions. Note that the configuration (number, coupling relationship, etc.) of the plurality of assemblies 1104A to 1104D is not limited to the above and may be modified in accordance with the design specifications.

[0130] In the wind propulsion device 1101 according to this embodiment, the plurality of blades 1110A to 1110G include two blades provided in line symmetry with respect to the straight line including the rotation axis RC. The ends of these two blades in the axial direction along the rotation axis RC form a trapezoid, as viewed from the direction parallel to the imaginary straight lines. When viewed from a direction parallel to the imaginary straight lines, axially adjacent two of the plurality of assemblies 1104A to 1104D are stacked together so that their respective blades 1110B to 1110G are arranged along the legs of trapezoids oriented in opposite directions. According to this configuration, axially adjacent two of the plurality of assemblies 1104A to 1104D are stacked together so that their respective blades 1110B to 1110G are arranged in a zigzag manner, and thus the same blades 1110B to 1110G can be coupled to each other.<Twelfth Embodiment>

[0131] The following describes a wind propulsion device 1201 (combination of the strut structure and the central blade) according to a twelfth embodiment. In the following description, the parts having the same functions as in the first embodiment will have the same names and reference numerals, and their functions will not be specifically described.

[0132] Fig. 21 is a side view showing a wind propulsion device 1201 (combination of the strut structure and the central blade) according to the twelfth embodiment. Fig. 22 is a perspective view showing an assembly of the wind propulsion device 1201 according to the twelfth embodiment. Referring to Figs. 21 and 22 together, the wind propulsion device 1201 of the twelfth embodiment includes a strut structure 1225 including a plurality of struts 27 connected to the frame 21, and a central blade 1210A in which the imaginary straight line connecting both ends thereof passes through the center of the frame 21.

[0133] Figs. 21 and 22 do not show the blades other than the central blade 1210A. In the example shown in Fig. 21, there are five stages of assemblies 1204A to 1204E; however, this embodiment is not limited thereto, and the number of stages of the assemblies can be modified in accordance with the design specifications.

[0134] As viewed from the vertical direction, the strut structure 1225 has a pair of struts 27 provided at both ends of each imaginary straight line, and transverse struts 28 extending between both ends of each imaginary straight line. The central blade 1210A has hollow structure. Note that the central blade 1210A may have solid structure. The upper and lower frames 21 are made of metal, for example. The central blade 1210A is made of GFRP (Glass Fiber Reinforced Plastics), for example. The upper and lower frames 21 have a plurality of grooves for fitting the central blade 1210A in their respective opposing parts. The central blade 1210A is fitted at the top apex thereof into the grooves in the upper frame 21 and at the bottom apex thereof into the grooves in the lower frame 21. The central blade 1210A may be bolted or welded. Note that the configuration (material, shape, connection relationship, etc.) of the upper and lower frames 21 and the central blade 1210A is not limited to the above and may be modified in accordance with the design specifications.

[0135] The wind propulsion device 1201 according to this embodiment includes the strut structure 1225 including the plurality of struts 27 connected to the frame 21, and the central blade 1210A in which the imaginary straight line connecting both ends thereof passes through the center of the frame 21. This configuration reduces manufacturing costs compared to the case with a central pillar located within the frame 21.<Thirteenth Embodiment>

[0136] The following describes a wind propulsion device 1301 (multiple stage stacking type) according to a thirteenth embodiment. In the following description, the parts having the same functions as in the first embodiment will have the same names and reference numerals, and their functions will not be specifically described.

[0137] Fig. 23 shows the wind propulsion device 1301 according to the thirteenth embodiment. As shown in Fig. 23, the wind propulsion device 1301 according to the thirteenth embodiment includes assemblies 1304 each formed of a rotator and a plurality of blades. A plurality of assemblies 1304 are arranged in the axial direction along the rotation axis RC. Supposing that N is the number of assemblies 1304 and M is a natural number, the plurality of assemblies 1304 are positioned differently from each other by 180×M / N degrees. The plurality of assemblies 1304 may be stacked vertically so that the height of the rotor sail body 1311 is 30 meters or more, for example.

[0138] In the example shown in Fig. 23, five assemblies 1304A to 1304E, among the plurality of assemblies 1304, are positioned differently from each other by 36 degrees. The five assemblies 1304A to 1304E are stacked vertically to a height of about 10 meters, for example. Note that the configuration (number and arrangement, etc.) of the plurality of assemblies is not limited to the above and can be modified in accordance with the design specifications.

[0139] An end plate 1306 is provided at the uppermost part of the rotor sail body 1311. The outer shape of the end plate 1306 may be a circle larger than the outermost shape of the rotor sail body 1311 as viewed from the vertical direction. The end plate 1306 may be bolted or welded to the upper frame 21 of the uppermost assembly 1304 of the rotor sail body 1311. The end plate 1306 provided at the uppermost part of the rotor sail body 1311 increases lift.

[0140] The wind propulsion device 1301 according to this embodiment includes the assemblies 1304 each formed of a rotator and a plurality of blades. A plurality of assemblies 1304 are arranged in the axial direction along the rotation axis RC. Supposing that N is the number of assemblies 1304 and M is a natural number, the plurality of assemblies 1304 are positioned differently from each other by 180×M / N degrees. This configuration reduces the rotational angle dependence of the propulsive force obtained from the wind. In addition, local buckling can be inhibited since the frames 21 serve as nodes.<Modifications>

[0141] The technical scope of the present invention is not limited to the embodiments described above but is susceptible of various modifications within the purport of the present invention.

[0142] Fig. 24 is a schematic view showing a wind propulsion device 1401A according to a first modification. Fig. 25 is a schematic view showing a wind propulsion device 1401B according to a second modification. Referring to Figs. 24 and 25 together, the wind propulsion devices 1401A, 1401B may include a plurality of assemblies having diameters that are smaller vertically upward. In the example shown in Fig. 24, the wind propulsion device 1401A includes a first assembly 1404A provided in the lowermost stage, a second assembly 1404B provided in the second-lowest stage and having a smaller diameter than the first assembly 1404A, and a third assembly 1404C provided in the uppermost stage and having a smaller diameter than the second assembly 1404B. For example, the lower part of the wind propulsion device 1401A (first assembly 1404A) may include struts (steel pipes) made of metal (e.g., steel) and having a larger thickness than the struts included in the other assemblies 1404B and 1404C. For example, the middle part of the wind propulsion device 1401A (second assembly 1404B) may include struts (steel pipes) made of steel and having a smaller thickness than the struts included in the first assembly 1404A. For example, the upper part of the wind propulsion device 1401A (third assembly 1404C) may include struts (aluminum pipes) made of metal (e.g., aluminum) and having a smaller weight than the struts included in the other assemblies 1404A and 1404B.

[0143] In the example shown in Fig. 25, in the wind propulsion device 1401B, the shape of the multiple assemblies stacked vertically is tapered, or narrower vertically upward. Note that the configuration (number, shape, material, etc.) of the plurality of assemblies constituting the wind propulsion devices 1401A and 1401B is not limited to the above and may be modified in accordance with the design specifications.

[0144] Fig. 26 is a schematic view showing a wind propulsion device 1501 (model using steel material) according to a third modification. Fig. 26 does not show the blades. As shown in Fig. 26, the wind propulsion device 1501 includes a strut structure 1525 that includes a plurality of struts 1527, 1528 connected to the frame 21. In this configuration, the rigidity of the wind propulsion device 1501 can be maintained with the central pillar 26 eliminated for weight reduction. In the example shown in Fig. 26, there are 12 stages of assemblies 1504; however, this modification is not limited thereto, and the number of stages of the assemblies can be modified in accordance with the design specifications. The strut structure 1525 may include a plurality of struts 1527 (steel pipes) made of metal (e.g., steel) and extending obliquely with respect to the vertical direction, and a plurality of struts 1528 (steel pipes) made of metal (e.g., steel) and extending parallel to the vertical direction. For example, the wind propulsion device 1501 may be constituted by a plurality of assemblies 1504 each having the same strut structure 1525, stacked vertically. The plurality of assemblies 1504 may be positioned differently from each other by a predetermined angle such that the ends of the respective struts 1527, 1528 are connected via the frame 21 and other members. The struts 1527, 1528 may be bolted or welded. Note that the configuration (material, shape, connection relationship, etc.) of the struts 1527, 1528 is not limited to the above and may be modified in accordance with the design specifications.

[0145] Fig. 27 is a schematic view showing a wind propulsion device 1601 (another example of fully cylindrical type) according to a fourth modification. Fig. 27 does not show the blades. As shown in Fig. 27, in the wind propulsion device 1601, the strut structure 1625 has an inner space 1625S formed therein so as to communicate in the axial direction along the rotation axis RC. The plurality of struts 1627 are arranged at equal intervals in the radial direction of the frame 21. The plurality of struts 1627 and the frame 21 are located within an imaginary cylinder around the rotation axis RC. The plurality of blades (not shown) extend across the inner space 1625S and are supported at respective opposite ends by the plurality of struts 1627. In this configuration, the plurality of struts 1627 are arranged at equal intervals in the radial direction, not in the circumferential direction, and thus the aerodynamic characteristics are improved. In the example shown in Fig. 27, the inner space 1625S does not contain the central pillar 26. Of the plurality of struts 1627 arranged at equal intervals in the radial direction of the frame 21, those located on one side in the radial direction are shown, whereas those located on the other side in the radial direction are not shown. At least some of the plurality of blades may be located to overlap the plurality of struts 1627, respectively, as viewed from the vertical direction.

[0146] The following describes other examples (modifications) of the movable body on which the wind propulsion device of the embodiments described above is installed. Sails of ships, airplane wings, rotor blades, and windmill blades have the same feature of generating lift, and the present invention can be applied to them with the effect of generating a large lift force (magnus force) while also generating electricity. For example, the configuration of the embodiments described above can be applied to movable bodies moving at a high speed (e.g., high-speed ships, automobiles, etc.). The wind propulsion device may also be applied to the wings of flying bodies, or may also be applies to airplanes, drones, flying cars, etc. If water resistance is to be ignored, railroads may be used. For example, the wind propulsion device may be installed on railroad vehicles running on underutilized local lines. The rotor sail mechanism is not limited to wind and can be applied to other fluids. For example, electricity may be generated by moving a ship across ocean currents (ocean current power generation). Ocean currents are slower in speed, but they have a higher density compared to air. The Japan Current flows at approximately 2 meters per second, but considering that its density is about 1,000 times greater than that of air, it is equivalent to a wind blowing at 20 meters per second. For ships, power transmission is challenging, and the capacity for onboard energy storage is inherently limited. Therefore, it is feasible to construct a factory that consumes a large amount of electricity within a ship (i.e., a factory ship). Examples include hydrogen production and electrolytic refining of aluminum. In this case, electrical power can be directly transported to the demand site by ship. For example, the wind propulsion device may be installed on a railroad container. In this case, electrical power can be supplied to refrigerated containers and the like, and thus it is no longer necessary to provide electricity via pantographs. Furthermore, it can be electrically isolated from the railroad system, the risk of accidents can be reduced. It can also be used as a power source for the braking system of freight cars. Similarly, the wind propulsion device may be installed on truck containers or ship containers.

[0147] The functions of the control unit according to the embodiments described above may be implemented in a program stored on a computer-readable storage medium, and the program stored on the storage medium may be loaded onto a computer system that then executes the program for processing. The "computer system" mentioned above may include an operating system (OS) or hardware such as peripheral devices. The "computer-readable storage medium" mentioned above refers to a storage device such as a portable medium like a flexible disc, a magneto-optical disc, a ROM (Read Only Memory), a flash memory or other writable non-volatile memory, and a DVD (Digital Versatile Disc), and a hard disk built-in to the computer system.

[0148] Further, the "computer-readable storage medium" includes storage media that retain the program for some period of time, like a volatile memory (for example, DRAM (Dynamic Random Access Memory)) in an information processing device receiving the program through a network such as the Internet or a communication line such as a telephone line, or in a computer system that operates as a client. The program mentioned above may be transmitted from a computer system that includes a storage device or the like storing the program to another computer system through a transmission medium or by a transmission wave in a transmission medium. The "transmission medium" for transmitting the program refers to a medium that operates to transmit information, like a network (communication network) such as the Internet or a communication line (communication wire) such as the telephone line. Only a part of the functions described above may be implemented in the above program. Further, the functions described above may be implemented by a combination of the above program and other programs previously stored on the computer system. That is, the above program may be what is called a difference file (a difference program).

[0149] The elements of the embodiments described above may be replaced with known elements within the purport of the present invention. Further, the modifications described above may be combined. In the embodiments disclosed herein, a member formed of multiple components may be integrated into a single component, or conversely, a member formed of a single component may be divided into multiple components. Irrespective of whether or not the components are integrated, they are acceptable as long as they are configured to attain the object of the invention. According to the foregoing embodiments disclosed herein, a plurality of functions may be distributively provided. Some or all of these functions may be integrally provided. Conversely, a different plurality of functions may be integrally provided. Some or all of these functions can be distributively provided. Irrespective of whether the functions are integrally or distributively provided, they are acceptable as long as they are configured to attain the object of the invention.LIST OF REFERENCE NUMBERS

[0150] 1, 201, 301, 401, 501, 601, 701, 801, 901, 1001, 1101, 1201, 1301, 1401A, 1401B, 1501, 1601: wind propulsion device; 2: ship (movable body); 4, 4A-4C, 704A-704C, 804A-804D, 1004A-1004D, 1104A-1104D, 1204A-1204E, 1304A-1304E, 1404A-1404C, 1504: assembly; 10A-10I, 610A-610I, 710A-710E, 810A, 1010A-1010G, 1110A-1110G, 1210A: blade; 20: rotator; 21: frame; 25, 225, 325, 425, 525, 1525, 1625: strut structure; 26: central pillar; 27, 28, 927, 928, 1527, 1528, 1627: strut; 328: spoke; 429: in-blade beam; 525S, 1625S: inner space; 770, 870A, 870B, 970: subassembly; 771: upper frame member; 772: lower frame member; RC: rotation axis

Claims

1. A wind propulsion device (1) installed on a movable body (2) and configured to generate propulsive force by receiving wind, the wind propulsion device (1) comprising: a rotator (20) including a frame (21) having an annular shape around a rotation axis (RC), the rotator (20) being rotatable around the rotation axis (RC); and a plurality of blades (10A-10I) provided such that imaginary straight lines connecting respective opposite ends in a direction orthogonal to the rotation axis (RC) are parallel, wherein the rotator (20) has a strut structure (25) including a plurality of struts (27) that are connected to the frame and support the plurality of blades (10A-10I), respectively.

2. The wind propulsion device (301) of claim 1, wherein as viewed from an axial direction along the rotation axis (RC), the strut structure (325) further includes: a central pillar (26) provided at a center of the frame (21); and a plurality of spokes (328) extending radially from the central pillar (26) and connected to the frame (21).

3. The wind propulsion device (401) of claim 1, wherein as viewed from an axial direction along the rotation axis (RC), the strut structure (425) further includes: a central pillar (26) provided at a center of the frame (21); and a plurality of in-blade beams (429) that extend radially outward from the central pillar (26) and are connected at respective outer ends to the plurality of struts (27), the plurality of in-blade beams (429) being provided in the plurality of blades (10A-10I), respectively.

4. The wind propulsion device (501) of claim 1, wherein the strut structure (525) has an inner space (525S) formed therein so as to communicate in an axial direction along the rotation axis (RC), wherein the plurality of struts (27) are arranged at equal intervals in a circumferential direction of the frame (21), wherein the plurality of struts (27) and the frame (21) are located within an imaginary cylinder around the rotation axis (RC), and wherein the plurality of blades (10A-10I) extend across the inner space (525S) and are supported at respective opposite ends by the plurality of struts (27).

5. The wind propulsion device (501) of claim 1, wherein the strut structure (525) has an inner space (525S) formed therein so as to communicate in an axial direction along the rotation axis (RC), wherein the plurality of struts (27) are arranged at equal intervals in a radial direction of the frame (21), wherein the plurality of struts (27) and the frame (21) are located within an imaginary cylinder around the rotation axis (RC), and wherein the plurality of blades (10A-10I) extend across the inner space (525S) and are supported at respective opposite ends by the plurality of struts (27).

6. A wind propulsion device (601) installed on a movable body (2) and configured to generate propulsive force by receiving wind, the wind propulsion device (601) comprising: a rotator (20) including a frame (21) having an annular shape around a rotation axis (RC), the rotator (20) being rotatable around the rotation axis (RCs); and a plurality of blades (610A-610I) provided such that imaginary straight lines connecting respective opposite ends in a direction orthogonal to the rotation axis (RC) are parallel, wherein the plurality of blades (610A-610I) include two blades provided in line symmetry with respect to a straight line including the rotation axis (RC), and the ends of the two blades in an axial direction along the rotation axis (RC) form a trapezoid, as viewed from a direction parallel to the imaginary straight lines.

7. The wind propulsion device (601) of claim 6, wherein the rotator (20) further has a plurality of struts (27) that are connected to the frame (21) and support the plurality of blades(610A-610I), respectively, and wherein as viewed from a direction parallel to the imaginary straight lines, two of the plurality of struts (27) located on opposite outer sides with a center at the rotation axis (RC) are provided along legs of a trapezoid.

8. The wind propulsion device (701) of any one of claims 1 to 7, comprising at least one assembly (704A-704C) each formed of the rotator (20) and the plurality of blades (710A-710E), wherein the at least one assembly (704A-704C) each includes a plurality of subassemblies (770) that are arranged in a circumferential or radial direction of the frame (21) and are detachably coupled to each other.

9. The wind propulsion device (701) of claim 8, wherein each of the plurality of subassemblies (770) includes an upper frame member (771) and a lower frame member (772), each formed in a semicircular shape as viewed in an axial direction along the rotation axis (RC), and wherein each of the plurality of blades (710A-710E) is connected at a top apex thereof to the upper frame member (771) and at a bottom apex thereof to the lower frame member (772).

10. The wind propulsion device (801) of claim 8, wherein the plurality of subassemblies (870A, 870B) comprise two subassemblies (870A, 870B) each having a semicircular shape as viewed in an axial direction along the rotation axis (RC), wherein the at least one assembly (804A-804D) comprises a plurality of assemblies (804A-804D) arranged along the axial direction, and wherein the plurality of assemblies (804A-804D) are stacked together such that respective two subassemblies (870A, 870B) are positioned differently in the circumferential direction and overlap as viewed from the axial direction.

11. The wind propulsion device (901) of claim 8, wherein each of the plurality of subassemblies (970) includes: an arc-shaped portion (971) that constitutes the frame (21) and is arc-shaped as viewed from an axial direction along the rotation axis (RC); and a plurality of struts (927) that are detachably connected to the arc-shaped portion (971).

12. The wind propulsion device (1301) of any one of claims 1 to 7, comprising a plurality of assemblies (1304A-1304E) each formed of the rotator (20) and the plurality of blades, wherein the plurality of assemblies (1304A-1304E) are arranged in an axial direction along the rotation axis (RC), and wherein supposing that N is a number of assemblies (1304A-1304E) and M is a natural number, the plurality of assemblies (1304A-1304E) are positioned differently from each other by 180×M / N degrees.

13. The wind propulsion device (1001) of claim 12, wherein the plurality of blades (1010A-1010G) include two blades provided in line symmetry with respect to a straight line including the rotation axis (RC), and the ends of the two blades in an axial direction along the rotation axis (RC) form a trapezoid, as viewed from a direction parallel to the imaginary straight lines, and wherein as viewed from a direction parallel to the imaginary straight lines, each of the plurality of assemblies (1004A-1004D) is disposed such that one end of the plurality of blades (1004A-1004D) in the axial direction is connected to another end of blades in the axial direction which blades are shifted by one position inward or outward around the rotation axis (RC).

14. The wind propulsion device (1101) of claim 12, wherein the plurality of blades (1110A-1110G) include two blades provided in line symmetry with respect to a straight line including the rotation axis (RC), and the ends of the two blades in an axial direction along the rotation axis (RC) form a trapezoid, as viewed from a direction parallel to the imaginary straight lines, and wherein as viewed from a direction parallel to the imaginary straight lines, two of the plurality of assemblies (1104A-1104D) that are adjacent to each other in the axial direction are stacked together such that the respective plurality of blades (1110A-1110G) are arranged along legs of trapezoids oriented in opposite directions.

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