Wind propulsion device

Abstract

To efficiently obtain thrust through the Magnus effect. [Solution] The wind power propulsion device of the embodiment is a wind power propulsion device installed on a ship that generates propulsion force by receiving wind, and comprises a wind turbine sail body that is rotatable about an axis extending vertically from the hull, and a cylindrical lower cylindrical part provided between the hull and the wind turbine sail body, connected to the lower part of the wind turbine sail body, and rotating integrally with the wind turbine sail body.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a sailboat in which vertical blades rotating around a vertical axis are provided in a windmill shape, a propeller is connected to the vertical axis, and the sailboat can be propelled based on wind power. The trailing edge of the vertical blade is connected to a wire extending from an axis eccentric in the downwind direction with respect to the axis of rotation of the leading edge of the vertical blade. The vertical blade is configured to be swingable around the axis of rotation of the leading edge of the vertical blade. Patent Document 2 discloses a wind power generator including a main shaft extending in the vertical direction, an upper bearing provided at the upper part of the main shaft, a lower bearing provided at the lower part of the main shaft, a frame connected to the main shaft via the upper bearing and the lower bearing, blades attached to the main shaft, a motor shaft core connected to the main shaft via the lower bearing, and a generator connected to the motor shaft core.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the case of a sailboat provided with vertical blades rotating around a main shaft extending in the vertical direction as in Patent Document 2, for the purpose of propulsion based on wind power as in Patent Document 1, when the bearing part becomes thick for the stability of the main shaft, the vertical blades become small, and the propulsion force due to the Magnus effect cannot be efficiently obtained.

[0005] The present invention was made to solve the above problems and aims to provide a wind-powered propulsion device that can efficiently obtain thrust due to the Magnus effect. [Means for solving the problem]

[0006] As a means of solving the above problems, an embodiment of the present invention has the following configuration. (1) An embodiment of the present invention is a wind power propulsion device installed on a ship that generates propulsion force by receiving wind, comprising: a wind turbine sail body that is rotatable about an axis extending vertically from the hull; and a cylindrical lower cylindrical part provided between the hull and the wind turbine sail body, connected to the lower part of the wind turbine sail body, and rotating integrally with the wind turbine sail body.

[0007] With this configuration, the lower cylindrical section rotates in conjunction with the windmill sail body, allowing the lower cylindrical section to also exert the Magnus effect and generate thrust. Therefore, thrust due to the Magnus effect can be obtained efficiently.

[0008] (2) The wind propulsion device described in (1) above further comprises a bearing that rotatably supports the wind turbine sail body, and the lower cylindrical portion may be provided so as to surround the bearing.

[0009] (3) The wind propulsion device described in (2) above further comprises a bracket that is provided so as to surround the bearing and is fixed to the hull, and the lower cylindrical portion may be provided so as to surround the bracket.

[0010] (4) The wind power propulsion device described in (3) above further comprises a drive unit for rotating the wind turbine sail body, and the bracket may be provided so as to cover the drive unit.

[0011] (5) The wind propulsion device described in (3) or (4) above comprises a bracket which is formed in a cylindrical shape that surrounds the bearing and extends in the vertical direction, and a flange which is formed in an annular shape that extends radially outward from the lower end of the main cylindrical part and is fixed to the upper surface of the hull, and the lower end of the lower cylindrical part may be positioned radially outward from the outer edge of the flange part.

[0012] (6) The wind propulsion device described in (5) above may have the lower end of the lower cylindrical portion positioned below the upper end of the main cylindrical portion in the vertical direction.

[0013] (7) The wind propulsion device described in (5) or (6) above may further include a stepped portion formed in a stepped shape that extends radially inward from the upper end of the main body cylindrical portion and then extends vertically upward. [Effects of the Invention]

[0014] According to the present invention, thrust can be efficiently obtained through the Magnus effect. [Brief explanation of the drawing]

[0015] [Figure 1] This is a perspective view of the wind power propulsion system according to the first embodiment. [Figure 2] This figure shows an example of the functional configuration of the wind power propulsion system of the first embodiment. [Figure 3] This diagram shows an example of energy flow in a wind power propulsion system, along with a comparative example. [Figure 4] This is a perspective view of the wind turbine sail body in the wind power propulsion device of the first embodiment. [Figure 5] This diagram shows the flow velocity distribution for an 8-bladed airfoil. [Figure 6] This diagram illustrates propulsion in the case of an eight-winged wing. [Figure 7] This diagram, following Figure 6, illustrates propulsion in the case of an eight-wing design. [Figure 8] This figure shows the lower cylindrical portion of the wind propulsion device according to the first embodiment. [Figure 9] It is a side view including a longitudinal section of a lower cylindrical portion in the wind propulsion device of the first embodiment. [Figure 10] It is an explanatory diagram of the operation of the labyrinth structure of the first embodiment. [Figure 11] It is a diagram showing the wind propulsion device of the second embodiment. [Figure 12] It is a diagram showing the wind propulsion device of the third embodiment.

Mode for Carrying Out the Invention

[0016] Hereinafter, the wind propulsion device and the wind propulsion system according to embodiments of the present invention will be described with reference to the drawings. In the following description, expressions indicating relative or absolute arrangements such as "parallel", "orthogonal", "center", "coaxial", etc. not only strictly mean such arrangements, but also include states where they are relatively displaced with tolerances and angles or distances that can obtain the same function. In the drawings used in the following description, the scales of each member are appropriately changed in order to make each member recognizable in size.

[0017] <Wind propulsion system> FIG. 1 is a perspective view of a wind propulsion system 100 according to the first embodiment. FIG. 2 is a diagram showing an example of the 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 installed on a ship 2 and generating a propulsion force by receiving wind, and a windmill sail control device 140 (an example of a wind control device) that controls the wind propulsion device 1.

[0018] The wind propulsion device 1 includes a windmill sail body 111 rotatable about an axis extending vertically from the hull 3, and a cylindrical lower cylindrical portion 112 provided between the hull 3 and the windmill sail body 111, connected to the lower part of the windmill sail body 111, and rotating integrally with the windmill sail body 111. The wind propulsion device 1 further includes an electric motor 41 (an example of a drive unit) that rotates the windmill sail body 111. The windmill sail body 111 includes an assembly 4 composed of a plurality of plate-shaped blades 10A to 10H integrally rotatably connected about a rotation axis.

[0019] The wind power control device 140 includes a speedometer 65 that acquires the moving speed of the ship 2, a detection unit 7 that acquires wind condition information including the current wind speed and wind direction in the area where the ship 2 is located, a calculation unit 126 that calculates the relative wind direction applied to the wind power propulsion device 1 based on the acquired moving speed of the ship 2 and wind condition information, and a rotation control unit 40 that controls the electric motor 41 according to the calculated relative wind direction to adjust the rotation speed of the wind turbine sail body 111. The wind power propulsion device 1 that constitutes the wind power propulsion system 100 functions as a wind turbine sail that propels the ship 2 by receiving wind and generating lift.

[0020] The wind power propulsion system 100 includes a wind power propulsion device 1 comprising the wind turbine sail body 111, lower cylindrical part 112, detection unit 7, receiving unit 8, and rotation control unit 40 described above; a remote control device 120 comprising an operating unit 121 operated to control the propulsion speed of the ship 2, and a determination unit 134 that determines the target thrust of the wind power propulsion device 1 and the target thrust of the propeller 51 driven by the prime mover 50 attached to the ship 2 according to the operating position of the operating unit 121; a wind turbine sail control device 140 that controls the rotation speed of the wind turbine sail body 111 around the rotation axis according to the target thrust of the wind power propulsion device 1; and a prime mover control device 150 that controls the rotation speed of the prime mover 50 according to the target thrust of the propeller 51. The wind power propulsion system 100 constitutes a system (ship integrated propulsion system) that integrates and controls two types of propulsion: propulsion by the wind power propulsion device 1 and propulsion by the propeller 51 driven by the prime mover 50.

[0021] The vessel 2 is equipped with a remote control device 120, a prime mover 50, a shaft 52, a propeller 51, a shaft horsepower meter 55, a detection system 60, a speedometer 65, and a prime mover control device 150. The vessel 2 does not necessarily have to be operated by a crew. For example, the vessel 2 may be an autonomously operated vessel.

[0022] The remote control device 120 executes a program (hereinafter referred to as the "ship control program") that controls the operation of the ship 2. The remote control device 120 functions as a device comprising a general control unit 130, an operation unit 121, a communication unit 122, an output unit 123, a calculation unit 126, and a storage unit 124 by executing the ship control program. The remote control device 120 includes a general control unit 130 that controls the operation of each functional unit of the remote control device 120.

[0023] The central control unit 130 includes a processor 131, such as a CPU (Central Processing Unit), connected by a bus, and a memory 132. The processor 131 reads the 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.

[0024] The control unit 130 communicates with the prime mover control unit 150, for example, by controlling the operation of the communication unit 122. The control unit 130 acquires information input via, for example, the operation unit 121. The control unit 130 records information generated by, for example, the execution of the ship control program in the storage unit 124. The control unit 130 acquires the rotational speed of the prime mover 50, for example. The control unit 130 outputs the acquired rotational speed to the prime mover control unit 150, for example. In the following description, the actual rotational speed value of the prime mover 50 acquired (determined) by the control unit 130 is also referred to as the "actual rotational speed".

[0025] The control unit 121 is a handle for controlling the speed and direction of the vessel 2. The control unit 121 accepts input from the crew. By operating the control unit 121, the crew inputs either the target engine speed or the engine direction of rotation, or both, to the remote control device 120. The target engine speed is the target rotational speed of the prime mover 50. The engine direction of rotation is the direction of rotation of the prime mover 50. The direction of rotation of the prime mover 50 is either forward or reverse. The direction of travel of the vessel 2 when the direction of rotation of the prime mover 50 is forward is opposite to the direction of travel of the vessel 2 when the direction of rotation of the prime mover 50 is reverse.

[0026] The control unit 121 outputs the target rotational speed indicated by the crew's operation to the control unit 130. The control unit 121 also outputs information indicating the engine rotation direction indicated by the crew's operation (hereinafter referred to as "rotation direction information") to the control unit 130. Note that the control unit 121 does not necessarily have to be operated by a crew member. For example, if the ship 2 is operating autonomously, the control unit 121 may be operated by the control unit 130 in accordance with the ship control program.

[0027] 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 speedometer 65, and the prime mover control device 150. The communication unit 122 communicates with the shaft horsepower meter 55, the detection system 60, the speedometer 65, and the prime mover control device 150, for example, via either wired or wireless communication. The communication unit 122 transmits information such as target rotational speed, actual rotational speed, and rotational direction to the prime mover control device 150.

[0028] The output unit 123 includes a display device such as a CRT (Cathode Ray Tube) display, a liquid crystal display, or an organic EL (Electro-Luminescence) display, as well as an output device such as a speaker or other audio output device. The output unit 123 may also be configured as an interface for connecting these output devices to the device. The output unit 123 outputs information related to the remote control device 120. For example, the output unit 123 outputs the operation results of the operation unit 121.

[0029] The calculation unit 126 is configured to include a processor such as a CPU (Central Processing Unit) connected by a bus (an example of a processing unit). The calculation unit 126 calculates various information related to the remote control device 120. For example, the calculation unit 126 calculates the relative wind direction on the wind propulsion device 1 based on the acquired moving speed of the ship 2 and wind condition information.

[0030] The memory unit 124 is configured using a storage device such as a magnetic hard disk drive or a semiconductor storage device. The memory unit 124 stores various information related to the remote control device 120. The memory unit 124 pre-stores, for example, a ship control program. The memory unit 124 stores, for example, information generated by the execution of the ship control program. The memory unit 124 stores, for example, a history of operations performed by the crew on the control unit 121. The memory unit 124 stores, for example, a history of the actual rotational speed of the prime mover 50.

[0031] The prime mover 50 is the engine that generates the propulsion force for the ship 2. The prime mover 50 converts the energy contained in the fuel into power. The type of fuel and the mechanism of operation of the prime mover 50 can be anything as long as it can convert the energy contained in the fuel into power. The prime mover 50 is, for example, a two-stroke diesel engine. The prime mover 50 may also be, for example, a four-stroke diesel engine or a gas engine. For the sake of simplicity, the ship 2 will be described below using the example of the prime mover 50 being a two-stroke engine.

[0032] The shaft 52 rotates due to the power generated by the prime mover 50. The rotational speed of the shaft 52 is proportional to the rotational speed of the prime mover 50. By rotating, the shaft 52 transmits the power generated by the prime mover 50 to the propeller 51.

[0033] The propeller 51 rotates due to the power generated by the prime mover 50. The rotation of the propeller 51 generates thrust that moves the ship 2.

[0034] The shaft horsepower meter 55 measures the power generated by the prime mover 50. The shaft horsepower meter 55 measures the power generated by the prime mover 50 by detecting the torsional strain occurring in the shaft 52 using either an electrical method, an optical method, or both.

[0035] The detection system 60 includes a sensor for detecting the rotational speed of the prime mover 50. The detection device may include, for example, a proximity sensor. The proximity sensor may be configured to output an ON signal when metal is located within a certain distance and an OFF signal when metal is not located within a certain distance. In this case, the proximity sensor outputs an ON signal when a convex portion of the irregularities on the surface of the shaft 52 is located within the detection range, and an OFF signal when a concave portion is located within the detection range. The detection system 60 may detect the rotational speed of the prime mover 50 based on such changes in the output of the proximity sensor and information obtained in advance indicating the spacing of the irregularities on the shaft 52.

[0036] The detection system 60 is not limited to proximity sensors; it may also include other types of devices. For example, the detection system 60 may include an encoder, a sensor for detecting engine noise, or a sensor for detecting engine vibration.

[0037] The speedometer 65 measures the speed of the vessel 2. The speedometer 65 measures the speed using, for example, the Doppler effect. Specifically, the speed measured by the speedometer 65 is the speed relative to the water.

[0038] The engine control device 150 controls the operation of the engine 50. The engine control device 150 determines the fuel injection amount and fuel injection timing based on the actual rotational speed acquired by the determination unit 134. The engine control device 150 controls the operation of the engine 50 so that the fuel injection amount is injected at the determined timing. The engine control device 150 controls the operation of the engine 50 by executing a fuel input amount calculation process, a fuel input control process, and a rotation direction control process.

[0039] The fuel input amount calculation process is a process that calculates the amount of fuel to be input to the prime mover 50 (hereinafter also referred to as "fuel input amount") using a predetermined input amount calculation function based on the target rotational speed and the actual rotational speed. The input amount calculation function is a function that uses the target rotational speed and the actual rotational speed as explanatory variables and the fuel input amount as the dependent variable. The prime mover control device 150 calculates the fuel input amount by executing the fuel input amount calculation process.

[0040] The fuel injection control process controls the degree to which a valve attached to the fuel injection pipe is opened and closed so that the amount of fuel calculated by the fuel injection amount calculation process is injected into the prime mover 50. The fuel injection pipe is a pipe that connects the prime mover 50 to a fuel tank (not shown), and is the pipe through which fuel flows from the fuel tank to the prime mover 50. The prime mover control device 150 injects the amount of fuel from the fuel tank into the prime mover 50 by executing the fuel injection control process.

[0041] The rotation direction control process is a process that controls the rotation direction of the prime mover 50 to the engine rotation direction. The rotation direction control process is a process that switches the rotation direction of the prime mover 50 between forward and reverse rotation by, for example, operating the clutch of the prime mover 50. The prime mover control device 150 controls the rotation direction of the prime mover 50 to the engine rotation direction by executing the rotation direction control process.

[0042] The direction of the torque output by the prime mover 50 corresponds to the direction of rotation of the prime mover 50. Therefore, the direction of the torque when the prime mover 50 is rotating in the forward direction is opposite to the direction of the torque when the prime mover 50 is rotating in the reverse direction. In addition, the power generated by the prime mover 50 is the value obtained by multiplying the magnitude of the torque output by the prime mover 50 by the rotational speed of the prime mover 50.

[0043] The central control unit 130 further comprises an acquisition unit 133 and a determination unit 134. The acquisition unit 133 acquires the detection results from the detection system 60 via the communication unit 122. The determination unit 134 acquires the power measured by the shaft horsepower meter 55 via the communication unit 122. The acquisition unit 133 acquires the ship speed measured by the speedometer 65 via the communication unit 122. The acquisition unit 133 acquires the amount of fuel input calculated by the prime mover control device 150 via the communication unit 122. The acquisition unit 133 acquires the target rotational speed and rotational direction information output by the operation unit 121 via the communication unit 122.

[0044] The determination unit 134 performs rotational speed determination processing. The rotational speed determination processing is a process that determines one of the rotational speeds obtained from the detection system 60 as the actual rotational speed of the prime mover 50, based on at least one of the target rotational speed, state information which is information about the state of the prime mover 50, and the ship speed of the ship 2. Candidates for the actual rotational speed are, for example, the first rotational speed and the second rotational speed. The state information includes, for example, the amount of fuel being injected. The state information also includes, for example, the power measured by the shaft horsepower meter 55.

[0045] The control unit 130 outputs the actual rotational speed determined by the determination unit 134 to the prime mover control device 150 via the communication unit 122. The control unit 130 outputs rotational direction information to the prime mover control device 150 via the communication unit 122. The control unit 130 outputs the target rotational speed to the prime mover control device 150 via the communication unit 122. The control unit 130 controls the operation of the output unit 123 to output information to the output unit 123.

[0046] <Flow of energy, etc., in wind power propulsion systems> Figure 3 shows an example of energy flow in the wind power propulsion system 100, along with a comparative example. In Figure 3, the flow of physical materials, the flow of information, and the flow of electricity (an example of energy flow) are indicated by various arrows.

[0047] As shown in Figure 3, in the comparative example (existing system), the wind force is first converted into rotational force to rotate the propeller. Therefore, in the comparative example, the propulsion efficiency is reduced due to the added force conversion. In contrast, the wind-powered propulsion system 100 of this embodiment treats the wind turbine sail as a propeller and uses the lift (Magnus force) generated by the wind-powered sail as the direct propulsion force. In other words, the wind-powered propulsion system 100 of this embodiment uses wind directly as the propulsion force. Therefore, the propulsion efficiency of the wind-powered propulsion system 100 of this embodiment is improved compared to the comparative example.

[0048] In this embodiment of the wind-powered propulsion system 100, wind is received by the wind turbine sail and converted into propulsion. For example, just as a sailing ship receives wind with its sails and converts it into propulsion, a wind turbine sailing ship also directly converts wind into propulsion with the wind turbine sail. The wind-powered propulsion system 100 of this embodiment is characterized by converting wind into propulsion as a sailing ship. Furthermore, in the wind-powered propulsion system 100 of this embodiment, the performance of the wind turbine sail as a sail is superior to that of a general rigid-wing sail.

[0049] <Electric motor> Referring to Figures 2 to 4, the rotation control unit 40 includes an electric motor 41 capable of rotating the wind turbine sail body 111. The electric motor 41 enables both the driving of the rotation of the wind turbine sail body 111 around the rotation axis, and the acceleration and deceleration of the rotation of the wind turbine 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.

[0050] <Brake part> The wind propulsion system 100 is further equipped with a braking unit 45 that brakes the rotation of the blades 10A to 10H around the rotation axis when the detection unit 7 detects a wind speed exceeding a threshold. The braking unit 45 reduces the rotation speed of the blades 10A to 10H around the rotation axis during strong winds, thereby reducing lift. Furthermore, by reducing lift during headwinds, induced drag can also be reduced.

[0051] <Energy Storage Section> The wind power propulsion system 100 further includes an energy storage unit 46 that stores the regenerative energy of the electric motor 41 generated when the rotation of the rotating shaft is decelerated. This allows the regenerative energy of the electric motor 41 stored in the energy storage unit 46 to be utilized. For example, the energy storage unit 46 may be configured to include a battery, a capacitor, or the like.

[0052] As mentioned above, while a windmill sail functions as a sail that converts wind power into propulsion, it also functions as a generator that can convert excess energy into electricity when the wind force exceeds the propulsion command. For example, the extracted electricity can be used for propulsion or for general purposes such as lighting.

[0053] <Acquisition part> The wind propulsion system 100 further includes an acquisition unit 133 that acquires the wind speed and direction of the currently occurring wind. The rotation control unit 40 increases the rotation speed of the blades 10A to 10H, which are rotated solely by the acquired wind, using the electric motor 41 if the rotation speed of the blades 10A to 10H, which are rotated only by the currently occurring wind, is below a threshold. For example, if the thrust that can be produced by a wind turbine sail rotating without energy supply using the wind speed and direction of the currently occurring wind is insufficient in response to a thrust command, the thrust can be amplified by increasing the speed with the power of the electric motor 41.

[0054] For example, the rotational speed thresholds for wings 10A to 10H (an example of a rotational speed threshold for wings) are calculated based on the thrust command. For example, the optimal rotational speed may be calculated from the thrust command, and based on the calculation result, the rotational speed of wings 10A to 10H may be increased by the electric motor 41.

[0055] <Relationship between wind turbine sail control and prime mover control> The thrust that a windmill sailing ship can generate without energy is limited. Therefore, the thrust that cannot be generated without energy can be supplemented by the drive mode of the windmill sail (rotation drive of blades 10A to 10H). For example, any thrust insufficient in the windmill sail drive mode can be supplemented by propeller 51 (propeller drive).

[0056] For example, the control unit 130 calculates the optimal rotational speed of the blades 10A to 10H around the rotation axis based on the received thrust command and the wind direction and wind speed detection results detected at the time of receiving the thrust command. For example, when controlling the rotational speed of the blades 10A to 10H, the q-axis current may be controlled by vector control, allowing for seamless control without distinction between driving and braking. For example, the control unit 130 may link the blades 10A to 10H with the propeller 51 and adjust the thrust ratio between the wind turbine sail and the propeller 51 to maximize energy efficiency.

[0057] As described above, the wind propulsion system 100 is a system that converts wind power into thrust. For example, when it receives a thrust command value from the remote control device 120, it calculates the optimal rotation speed of the blades 10A to 10H based on the wind direction and wind speed to produce that thrust. Then, it controls the electric motor 41 to achieve the calculated rotation speed. In this case, the rotation speed includes the direction of rotation. In the case of reverse rotation, it is controlled with a negative speed.

[0058] For example, if the natural thrust of the wind turbine sailboat is insufficient, the propeller 51 is also driven. Depending on the wind direction, if the wind power propulsion system 1 is more efficient than the propeller 51, the electric motor 41 is driven to increase its rotational speed and thus increase thrust. On the other hand, if the propeller 51 is more efficient than the wind power propulsion system 1, the wind power propulsion system 1 is left in a naturally starting state, and the propeller 51 is rotated to generate thrust. It is also possible to drive both the electric motor 41 of the wind power propulsion system 1 and the propeller 51.

[0059] For example, the rotational moment of a ship can be adjusted by arranging multiple windmill sails on the hull. For instance, multiple windmill sails can be arranged fore and aft on the hull, and the rotation speeds of the fore and aft windmill sails can be made different. This can generate a moment by making the forces acting on the ship in the lateral direction different for the fore and aft windmill sails.

[0060] <Rudder control section> Referring to Figure 2, the wind propulsion system 100 further includes a rudder control unit 125 that controls the rudder so as to turn in the opposite direction to the inertial force generated in the opposite direction to the direction in which the rotational speed of the blades 10A to 10H is changed by the rotation control unit 40. This allows the rudder to work in conjunction with the rudder to prevent the hull 3 from rotating, anticipating that torque will act on the hull 3 due to the aforementioned inertial force.

[0061] For example, when changing the rotational speed of the blades 10A to 10H by driving or braking, the rudder may be used in conjunction with the propulsion system. For example, when the electric motor 41 is in a free state and the blades 10A to 10H are rotating freely, it is not necessary to use the rudder in conjunction with the propulsion system. For example, if the brakes are applied or the propulsion system is driven to change the rotational speed of the blades 10A to 10H, torque will act on the hull 3, and the hull 3 may rotate. To prevent this, if only one wind propulsion system 1 is installed, it is advisable to anticipate that torque will act on the hull 3 and use the rudder in conjunction with the propulsion system to prevent the hull 3 from rotating.

[0062] <Wind propulsion device> Referring to Figures 1 and 2, the wind power propulsion device 1 is installed on the ship 2 and functions as a wind turbine sail that generates thrust by receiving wind. In the example shown in the figures, one wind power propulsion device 1 is installed on the forward part (bow) of the hull 3. Note that the installation configuration of the wind power propulsion device 1 (installation location, number of units, etc.) is not limited to the above and can be changed according to the design specifications.

[0063] <Windmill sail body> Figure 4 is a perspective view of the wind turbine sail body in the wind power propulsion device 1 of the first embodiment. Referring also to Figure 4, the wind propulsion device 1 includes a wind turbine sail body 111 that can rotate around an axis RC (a dashed line shown in Figure 4) extending vertically from the hull 3. The wind turbine sail body 111 includes an assembly 4 consisting of rotating bodies 20A and 20B that can rotate around the axis RC, and a plurality of plate-shaped blades 10A to 10H fixed to the rotating bodies 20A and 20B, respectively.

[0064] Multiple wings 10A to 10H are arranged such that the imaginary lines connecting the ends of each wing 10A to 10H are parallel. The ends of the multiple wings 10A to 10H are positioned on an imaginary circle centered on the axis of rotation. The longest of the multiple wings 10A to 10H (the innermost wing) is arranged such that the length of the imaginary line (the length from one end of the wing to the other, the so-called chord length) is at least half the diameter of the imaginary circle centered on the axis of rotation. The outermost of the multiple wings 10A to 10H may have a chord length of less than half the diameter of the imaginary circle centered on the axis of rotation. Note that the chord lengths of the multiple wings are not limited to the above and can be changed according to the design specifications.

[0065] In the example shown, the virtual circle centered on the axis of rotation is a perfect circle when viewed from the vertical. However, the shape of the virtual circle when viewed from the vertical is not limited to the above; it could be an ellipse, an oblong, a quadrilateral, or a closed ring formed by connecting curves.

[0066] The rotating bodies 20A and 20B are plate-shaped rotating plates 20A and 20B. Multiple blades 10A to 10H are each fixed to one surface of the rotating plates 20A and 20B. In the example shown in the figure, the rotating plates 20A and 20B consist of a lower plate 20A to which the lower ends of the multiple blades 10A to 10H are fixed, and an upper plate 20B to which the upper ends of the multiple blades 10A to 10H are fixed. For example, the lower plate 20A is fixed to the upper part of the lower cylindrical part 112.

[0067] The rotating plates 20A and 20B comprise an annular frame portion 21 and a plurality of beam portions 22 that are connected at both ends to the inner circumference of the frame portion 21 and are arranged parallel to each other. In the example shown in the figure, three beam portions 22 are connected at both ends to the inner circumference of the frame portion 21 and are arranged at equal intervals. The configuration of the beam portions 22 (number and arrangement, etc.) is not limited to the above and can be changed according to the design specifications. For example, the configuration (shape, etc.) of the rotating bodies 20A and 20B may be a solid disc (an example of a rotating plate) or a hollow disc. The configuration of the rotating bodies 20A and 20B is not limited to the above and can be changed according to the design specifications.

[0068] In the example shown in the figure, assembly 4 has one stage, but the number of stages in assembly 4 can be changed according to the design specifications, and is not limited to the above. For example, if there are multiple assemblies 4, A and B, the rotating bodies 20A and 20B of assembly 4A and assembly 4B may be common to both. For example, the installation method of the rotating bodies 20A and 20B for multiple assemblies 4 can be changed according to the design specifications. Also, A and B of assembly 4 may have the same shape, and the rotating bodies 20A and 20B may be bolted together or welded together.

[0069] The multiple wings 10A to 10H are wings 10A to 10H that extend in the vertical direction. The multiple wings 10A to 10H are arranged so as to be symmetric with respect to a center line that passes through the center of rotation of the axis of rotation and is parallel to the imaginary straight line when viewed from the vertical direction. The multiple wings 10A to 10H are arranged so as to be symmetric with respect to a center line that passes through the center of rotation of the axis of rotation and is perpendicular to the imaginary straight line when viewed from the vertical direction.

[0070] In the example shown in the figure, each of the eight wings 10A to 10H extends vertically so as to intersect with the three beam sections 22 of the rotating plates 20A and 20B. In the example shown in the figure, of the eight wings 10A to 10H, the four wings 10A to 10D on one side of the rotation center and the four wings 10E to 10H on the other side are arranged at equal intervals. Note that the configuration (number and arrangement, etc.) of the wings 10A to 10H is not limited to the above and can be changed according to the design specifications.

[0071] <Propulsion in the case of an 8-wing design> Figure 5 shows the velocity distribution for an 8-bladed design. Figure 6 is a diagram illustrating propulsion for an 8-bladed design. Figure 7 is a diagram illustrating propulsion for an 8-bladed design, following on from Figure 6. In the example figures, a support is shown at the center of rotation of the rotation axis, but the support is not required.

[0072] Referring to Figures 5 through 7, the eight blades rotate regardless of wind direction. In the eight blades, the portion in front of the center of rotation aligns with the direction of rotation, so the wind in front accelerates and the wind in behind decelerates. According to Bernoulli's principle, this causes the pressure in front to decrease and the pressure in behind to increase. This pressure difference generates a thrust force perpendicular to the wind direction. This thrust force is called the Magnus force. If the wind direction is reversed, the rotation is reversed. While the Magnus force is inherently a force generated by the rotation of a cylinder or sphere, the thrust generated by parallel wings is called the Magnus force because the force generation mechanism is similar. Furthermore, because the Magnus force acts perpendicular to the wind, it is also called lift.

[0073] In this embodiment, the eight blades are positioned so that both ends lie on a virtual circle centered on the axis of rotation, and the virtual lines connecting the ends of each blade are parallel. This allows for a greater thrust compared to cases with seven or fewer blades. Although it is affected by the Reynolds number, i.e., size and wind speed, the thrust generally tends to increase as the number of blades increases. For example, an 18-blade design is also possible.

[0074] <Lower cylindrical section> Figure 8 shows the lower cylindrical portion 112 of the wind power propulsion device 1 according to the first embodiment. Figure 9 is a side view including a longitudinal cross-section of the lower cylindrical portion 112 of the wind power propulsion device 1 according to the first embodiment. Referring to Figures 8 and 9, the lower cylindrical section 112 is provided between the hull 3 and the windmill sail body 111. The upper end of a vertical shaft 5, which extends vertically, is connected to the lower center of the windmill sail body 111. The output shaft of an electric motor 41 is connected to the lower end of the vertical shaft 5. The windmill sail body 111 rotates together with the vertical shaft 5 due to the rotational drive of the electric motor 41.

[0075] The lower cylindrical section 112 is connected to the lower part of the windmill sail body 111. The lower cylindrical section 112 rotates together with the windmill sail body 111. The lower cylindrical section 112 is formed in a cylindrical shape centered on an axis RC (a dashed line shown in Figure 9) that extends vertically from the hull 3. The lower cylindrical section 112 functions as a cylindrical wing.

[0076] The radial center of the lower cylindrical portion 112 is located coaxially with the vertical axis 5. The lower cylindrical portion 112 is connected to the lower plate 20A of the wind turbine sail body 111. The outer shape of the lower cylindrical portion 112 may be the same as that of the lower plate 20A of the wind turbine sail body 111 when viewed from the vertical direction. The lower cylindrical portion 112 may be bolted or welded to the lower plate 20A of the wind turbine sail body 111.

[0077] The height of the lower cylindrical section 112 is preferably 3m or more, and more preferably 4m or more. The height of the lower cylindrical section 112 corresponds to the vertical distance from the top surface of the hull 3 to the upper end of the lower cylindrical section 112.

[0078] Since the wind propulsion device 1 installed on the deck of the hull 3 may be hit by waves during navigation, the height of the lower cylindrical section 112 can be set to the height at which waves may hit it. Also, to prevent objects from coming into contact with the rotating wind turbine sail body 111, the height of the lower cylindrical section 112 can be set to the height at which objects may come into contact with it. If it is difficult to install the rotation drive mechanism of the wind turbine sail body 111, including the electric motor 41, inside the wind turbine sail body 111, the height occupied by the rotation drive mechanism installed inside the lower cylindrical section 112 can be set to the height of the lower cylindrical section 112. Note that the height of the lower cylindrical section 112 is not limited to the above and can be changed according to the design specifications.

[0079] The wind propulsion device 1 further includes bearings 70A and 70B that rotatably support the wind turbine sail body 111. The lower cylindrical portion 112 is provided so as to surround the bearings 70A and 70B. Multiple bearings 70A and 70B may be provided. In the example shown in the figure, two bearings 70A and 70B are provided, spaced apart in the vertical direction. The two bearings 70A and 70B consist of an upper bearing 70A provided on the upper end side of the vertical axis 5 surrounded by the lower cylindrical portion 112, and a lower bearing 70B provided below the upper bearing 70A and on the hull 3 side. Note that the configuration (number and arrangement, etc.) of the bearings 70A and 70B is not limited to the above and can be changed according to the design specifications. For example, instead of providing bearings vertically, bearings that are not divided vertically (e.g., cross roller bearings or double-row angular contact bearings) may be provided as bearings. In this case, the height of the lower cylindrical portion 112 in which the bearing is installed can be made lower than if the bearings were installed both above and below.

[0080] <bracket> The wind propulsion device 1 further includes a bracket 80 that surrounds the bearings 70A and 70B and is fixed to the hull 3. The lower cylindrical portion 112 is provided to surround the bracket 80. In the example shown in the figure, the bracket 80 is provided to surround the two bearings 70A and 70B. The bracket 80 is provided to cover the upper bearing 70A and the lower bearing 70B from the outer circumference. Note that the manner in which the bracket 80 surrounds the bearings 70A and 70B (number of bearings surrounded, method of covering, etc.) is not limited to the above and can be changed according to the design specifications.

[0081] The bracket 80 is provided to cover the drive unit 41. In the example shown in the figure, the drive unit 41 is housed in a recess 3a that is recessed downward from the upper surface of the hull 3. The drive unit 41 is installed on the bottom surface of the recess 3a. The vertical shaft 5 of the wind turbine sail body 111 is provided coaxially with the output shaft of the drive unit 41. The output shaft of the drive unit 41 is connected to the vertical shaft 5 of the wind turbine sail body 111. The bracket 80 is provided to cover the drive unit 41 from the upper vertical side. Note that the manner in which the bracket 80 covers the drive unit 41 (how it covers it, etc.) is not limited to the above and can be changed according to the design specifications.

[0082] The bracket 80 comprises a main cylindrical portion 81 that surrounds the bearings 70A and 70B and extends vertically, and a flange portion 82 that is annular in shape extending radially outward from the lower end of the main cylindrical portion 81 and fixed to the upper surface of the hull 3. The flange portion 82 of the bracket 80 may be bolted to or welded to the upper surface of the hull 3.

[0083] The bracket 80 may be provided with ribs 84 to reinforce it. In the example shown in the figure, multiple ribs 84 are provided at intervals around the outer circumference of the main cylindrical portion 81. The ribs 84 are formed so that their radial length gradually increases from the upper end to the lower end of the main cylindrical portion 81, and then extend to the upper surface of the flange portion 82 with a uniform radial length. The configuration of the ribs 84 (number, shape, etc.) is not limited to the above and can be changed according to the design specifications.

[0084] <Labyrinth structure> The lower end of the lower cylindrical portion 112 is positioned radially outward from the outer edge of the flange portion 82. In the example shown in Figure 9, the lower end of the lower cylindrical portion 112 is positioned radially outward from the outer edge of the flange portion 82 and vertically above the upper surface of the flange portion 82. The lower end of the lower cylindrical portion 112 and the outer edge of the flange portion 82 form a labyrinth structure LS1 (first labyrinth structure LS1).

[0085] The lower end of the lower cylindrical portion 112 is positioned vertically below the upper end of the main cylindrical portion 81. In the example shown in Figure 9, the lower end of the lower cylindrical portion 112 is positioned vertically below the upper end of the main cylindrical portion 81 and vertically above the upper surface of the flange portion 82. The lower end of the lower cylindrical portion 112 is positioned vertically below the upper end of the lower bearing 70B. The lower end of the lower cylindrical portion 112 and the upper end of the main cylindrical portion 81 constitute a labyrinth structure LS2 (second labyrinth structure LS2). The second labyrinth structure LS2 is provided vertically above the first labyrinth structure LS1.

[0086] The bracket 80 further includes a stepped portion 83 that extends radially inward from the upper end of the main cylindrical portion 81 and then extends vertically upward. In the example shown in Figure 9, the stepped portion 83 is positioned vertically above the upper end of the upper bearing 70A. The lower end of the lower cylindrical portion 112 and the stepped portion 83 on the upper end side of the main cylindrical portion 81 constitute a labyrinth structure LS3 (third labyrinth structure LS3). The third labyrinth structure LS3 is positioned vertically above the first labyrinth structure LS1 (and even higher than the second labyrinth structure LS2).

[0087] Furthermore, since friction between the movable parts (lower cylindrical part 112 and rotating body 20A) and the fixed parts (hull 3 and bracket 80) creates resistance, a gap will be created between the movable and fixed parts when considering manufacturing tolerances. In addition, if a rubber sealing member such as an O-ring is provided between the movable and fixed parts, the rotational resistance will increase. Therefore, a labyrinth structure with a difference in height is necessary to allow water to enter between the movable and fixed parts, while preventing water from entering the bearing parts, etc.

[0088] <The effect of the labyrinth structure> Figure 10 is an explanatory diagram of the operation of the labyrinth structures LS1, LS2, and LS3 of the first embodiment. In the example shown in Figure 10, arrows V1, V2, and V3 illustrate an example of the water intrusion path when waves hit the hull 3. In this embodiment, the lower end of the lower cylindrical portion 112 and the outer peripheral edge of the flange portion 82 constitute the first labyrinth structure LS1. This allows waves to be applied in the direction of arrow V1, and even if waves enter the inside of the lower cylindrical portion 112, penetration in the directions of arrows V2 and V3 can be suppressed.

[0089] Furthermore, since the lower end of the lower cylindrical portion 112 and the upper end of the main cylindrical portion 81 form a second labyrinth structure LS2, even if waves enter the inside of the lower cylindrical portion 112, their penetration in the directions of arrows V2 and V3 can be suppressed. Furthermore, the lower end of the lower cylindrical portion 112 and the stepped portion 83 on the upper end side of the main cylindrical portion 81 form a third labyrinth structure LS3, which suppresses intrusion in the direction of arrows V2 and V3 even if waves enter the inside of the lower cylindrical portion 112.

[0090] <Effects and Effects> As described above, the wind power propulsion device 1 according to this embodiment is a wind power propulsion device installed on a ship 2 that generates thrust by receiving wind, and comprises a wind turbine sail body 111 that is rotatable about an axis RC extending vertically from the hull 3, and a cylindrical lower cylindrical part 112 provided between the hull 3 and the wind turbine sail body 111, connected to the lower part of the wind turbine sail body 111, and rotating integrally with the wind turbine sail body 111.

[0091] With this configuration, the lower cylindrical section 112 rotates in conjunction with the windmill sail body 111, allowing the lower cylindrical section 112 to also exert the Magnus effect and generate thrust. Therefore, thrust due to the Magnus effect can be obtained efficiently. Furthermore, by connecting the lower cylindrical part 112 to the lower part of the windmill sail body 111, it is possible to suppress waves from hitting the windmill sail body 111. In addition, it is possible to suppress objects on the sailing ship from coming into contact with the rotating windmill sail body 111.

[0092] The wind power propulsion device 1 according to this embodiment further comprises bearings 70A and 70B that rotatably support the wind turbine sail body 111. The lower cylindrical portion 112 is provided so as to surround the bearings 70A and 70B. With this configuration, the bearings 70A and 70B are surrounded by the lower cylindrical portion 112, which suppresses the effects of waves on the bearings 70A and 70B.

[0093] The wind propulsion device 1 according to this embodiment further comprises a bracket 80 that surrounds the bearings 70A and 70B and is fixed to the hull 3. The lower cylindrical portion 112 is provided to surround the bracket 80. With this configuration, the bearings 70A and 70B are surrounded by the bracket 80, which prevents waves from affecting the bearings 70A and 70B even if waves enter the inside of the lower cylindrical portion 112.

[0094] The wind power propulsion device 1 according to this embodiment further comprises a drive unit 41 for rotating the wind turbine sail body 111. The bracket 80 is provided so as to cover the drive unit 41. With this configuration, the drive unit 41 is covered by the bracket 80, which prevents waves from affecting the drive unit 41 even if waves enter the inside of the lower cylindrical portion 112.

[0095] The bracket 80 according to this embodiment comprises a main cylindrical portion 81 that surrounds the bearings 70A and 70B and is formed in a cylindrical shape extending vertically, and a flange portion 82 that is formed in an annular shape extending radially outward from the lower end of the main cylindrical portion 81 and is fixed to the upper surface of the hull 3. The lower end of the lower cylindrical portion 112 is positioned radially outward from the outer peripheral edge of the flange portion 82. With this configuration, the labyrinth structure LS1 between the lower end of the lower cylindrical portion 112 and the outer peripheral edge of the flange portion 82 prevents waves from affecting the bearings 70A and 70B even if waves enter the inside of the lower cylindrical portion 112.

[0096] In this embodiment, the lower end of the lower cylindrical portion 112 is positioned vertically below the upper end of the main cylindrical portion 81. With this configuration, the labyrinth structure LS2 between the lower end of the lower cylindrical portion 112 and the upper end of the main cylindrical portion 81 prevents waves from affecting the bearings 70A and 70B even if waves enter the inside of the lower cylindrical portion 112.

[0097] The bracket 80 according to this embodiment further includes a stepped portion 83 that extends radially inward from the upper end of the main cylindrical portion 81 and then extends vertically upward, forming a stepped shape. With this configuration, the labyrinth structure LS3 between the lower end of the lower cylindrical portion 112 and the stepped portion 83 on the upper end side of the main cylindrical portion 81 prevents waves from affecting the bearings 70A and 70B even if waves enter the inside of the lower cylindrical portion 112.

[0098] <Second Embodiment> The wind power propulsion device 201 according to the second embodiment will be described below. In the following description, parts having the same functions as those described in the first embodiment will be given the same names and reference numerals, and a detailed explanation of their functions will be omitted.

[0099] Figure 11 shows the wind power propulsion device 201 of the second embodiment. As shown in Figure 11, in the wind power propulsion device 201 according to the second embodiment, the wind turbine sail body 211 comprises a plurality of assemblies 204A to 204F arranged vertically. The plurality of assemblies 204A to 204F may be stacked vertically, for example, so that the height of the wind turbine sail body 211 is 2m or more.

[0100] In the example shown in Figure 11, six assemblies 204A to 204F are arranged vertically. If N is the number of assemblies and M is a natural number, the assemblies 204A to 204F may be arranged with a offset of 180 × M / N degrees from each other. Note that the configuration (number and arrangement, etc.) of the assemblies 204A to 204F is not limited to the above and can be changed according to the design specifications.

[0101] An end plate 206 is provided at the top of the wind turbine sail body 211. The outer shape of the end plate 206 may be a circle that is larger than the outermost shape of the wind turbine sail body 211 when viewed from the vertical direction. The end plate 206 may be bolted or welded to the upper plate 20B of the uppermost assembly 204F of the wind turbine sail body 211.

[0102] In the wind power propulsion device 201 according to the second embodiment, an end plate 206 is provided at the top of the wind turbine sail body 211. This configuration allows for increased lift.

[0103] <Third Embodiment> The wind propulsion device 301 according to the third embodiment will be described below. In the following description, parts having the same functions as those described in the second embodiment will be given the same names and reference numerals, and a detailed explanation of their functions will be omitted.

[0104] Figure 12 shows the wind power propulsion device 301 of the third embodiment. As shown in Figure 12, the wind power propulsion device 301 according to the third embodiment includes a wind turbine sail body 211 having a plurality of assemblies 204A to 204F arranged vertically, a frame 330 extending vertically upward from the hull 3 and rotatably supporting the wind turbine sail body 211, and a wire 331 stretched between the upper end of the frame 330 and the hull 3.

[0105] In the example shown in Figure 12, the frame 330 extends vertically, straddling the windmill sail body 211 and the lower cylindrical section 112. The windmill sail body 211 is rotatably supported relative to the frame 330 around a rotation axis via bearings (not shown). The upper end of the frame 330 is positioned vertically above the end plate 206. The wire 331 is stretched in an inverted V shape. The wire 331 is stretched such that the horizontal spacing gradually increases as it moves vertically downward from the upper end of the frame 330. The lower end of the wire 331 is fixed, for example, to the upper surface of the hull 3.

[0106] The wind power propulsion device 301 according to the third embodiment includes a wind turbine sail body 211 having a plurality of assemblies 204A to 204F arranged vertically, a frame 330 extending vertically upward from the hull 3 and rotatably supporting the wind turbine sail body 211, and a wire 331 stretched between the upper end of the frame 330 and the hull 3. With this configuration, even if the windmill sail body 211 comprises multiple assemblies 204A to 204F, the tension of the wire 331 and the frame 330 can support the windmill sail body 211 and the lower cylindrical section 112 on the hull 3. Furthermore, even if it is necessary to tilt the windmill sail body 211, the tension of the wire 331 can reduce the load on the windmill sail body 211.

[0107] <Variation> It should be noted that the technical scope of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention.

[0108] In the embodiments described above, a bearing further rotatably supports the wind turbine sail body, and the lower cylindrical portion is provided to surround the bearing. However, the invention is not limited to this. For example, at least a part of the bearing may be provided outside the lower cylindrical portion (radially outward or axially outward). The manner in which the lower cylindrical portion surrounds the bearing can be changed according to the design specifications.

[0109] In the embodiments described above, an example was given in which a bracket is provided to surround the bearing and fixed to the hull, and the lower cylindrical portion is provided to surround the bracket, but the invention is not limited to this. For example, at least a part of the bracket may be provided outside (radially outward) the lower cylindrical portion. The manner in which the lower cylindrical portion surrounds the bracket can be changed according to the design specifications.

[0110] In the embodiments described above, an example was given in which a drive unit for rotating the wind turbine sail body is further provided, and the bracket is provided so as to cover the drive unit, but the invention is not limited to this. For example, at least a part of the drive unit may be provided outside (radially outward) of the bracket. The manner in which the bracket covers the drive unit can be changed according to the design specifications.

[0111] In the embodiment described above, the bracket comprises a main cylindrical portion formed in a cylindrical shape that surrounds the bearing and extends vertically, and a flange portion formed in an annular shape that extends radially outward from the lower end of the main cylindrical portion and is fixed to the upper surface of the hull, with the lower end of the lower cylindrical portion positioned radially outward from the outer peripheral edge of the flange portion. However, the embodiment is not limited to this example. For example, the lower end of the lower cylindrical portion may be positioned radially inward from the outer peripheral edge of the flange portion. The positional relationship between the lower end of the lower cylindrical portion and the outer peripheral edge of the flange portion can be changed according to the design specifications.

[0112] In the embodiment described above, the lower end of the lower cylindrical portion was explained as being positioned vertically below the upper end of the main cylindrical portion, but this is not limited to this example. For example, the lower end of the lower cylindrical portion may be positioned vertically above the upper end of the main cylindrical portion. The positional relationship between the lower end of the lower cylindrical portion and the upper end of the main cylindrical portion can be changed according to the design specifications.

[0113] The bracket according to the above embodiment was described with an example that further includes a stepped portion that extends radially inward from the upper end of the main cylindrical portion and then vertically upward, but it is not limited to this. For example, the bracket does not have to include a stepped portion. The installation method of the stepped portion can be changed according to the design specifications.

[0114] Processing may be performed by recording a program for realizing the functions of the control unit according to the above embodiment on a computer-readable recording medium, having a computer system read the program recorded on this recording medium, and executing it. Furthermore, the term "computer system" as used herein may include an operating system (OS) or hardware such as peripheral devices. Furthermore, "computer-readable recording media" refers to writable non-volatile memory such as flexible disks, magneto-optical disks, ROM (Read Only Memory), and flash memory, portable media such as DVDs (Digital Versatile Discs), and storage devices such as hard disks built into computer systems.

[0115] Furthermore, "computer-readable recording media" also includes volatile memory (such as DRAM (Dynamic Random Access Memory)) within information processing devices or client computer systems that retain programs for a certain period of time when programs are transmitted via networks such as the Internet or communication lines such as telephone lines. Furthermore, the above program may be transmitted from a computer system that stores the program in a memory device or the like to another computer system via a transmission medium or by transmission waves within the transmission medium. Here, the "transmission medium" used to transmit the program refers to a medium that has the function of transmitting information, such as a network (communication network) like the Internet or a communication line (communication line) like a telephone line. Furthermore, the above program may be intended to implement some of the functions described above. Moreover, the above program may be a so-called differential file (differential program) that can implement the functions described above in combination with a program already recorded in the computer system.

[0116] Furthermore, it is possible to replace the components in the above-described embodiments with well-known components without departing from the spirit of the present invention. Also, the above-described modifications may be combined. Among the embodiments disclosed herein, those composed of multiple objects may be integrated, and conversely, those composed of a single object may be divided into multiple objects. Whether or not they are integrated, the invention can be constructed in a way that achieves its objective. In the embodiments disclosed herein, those in which multiple functions are provided in a distributed manner may have some or all of those multiple functions integrated into a single unit, and conversely, those in which multiple functions are integrated may have some or all of those functions provided in a distributed manner. Whether the functions are integrated or distributed, the configuration should be such that the objective of the invention can be achieved. [Explanation of symbols]

[0117] 1, 201, 301…wind propulsion device, 2…ship, 3…hull, 41…electric motor (drive unit), 70A, 70B…bearing, 80…bracket, 81…main cylinder section, 82…flange section, 83…step section, 111, 211…wind turbine sail body, 112…lower cylindrical section

Claims

1. A wind-powered propulsion system installed on a ship that generates thrust by receiving wind, A windmill sail body that can rotate around an axis extending vertically from the hull, It comprises a cylindrical lower cylindrical portion provided between the hull and the windmill sail body, connected to the lower part of the windmill sail body, and rotating integrally with the windmill sail body, Wind propulsion device.

2. The wind turbine sail body is further provided with a bearing that rotatably supports it, The lower cylindrical portion is provided so as to surround the bearing. The wind propulsion device according to claim 1.

3. The aforementioned bearing is further provided with a bracket that surrounds it and is fixed to the hull, The aforementioned lower cylindrical portion is provided so as to surround the bracket. The wind propulsion device according to claim 2.

4. The wind turbine sail body is further equipped with a drive unit for rotating the wind turbine sail body, The bracket is provided so as to cover the drive unit. The wind propulsion device according to claim 3.

5. The aforementioned bracket is The main body is formed in a cylindrical shape that surrounds the bearing and extends in the vertical direction, It comprises a flange portion formed in an annular shape extending radially outward from the lower end of the main body cylindrical portion and fixed to the upper surface of the hull, The lower end of the lower cylindrical portion is positioned radially outward from the outer edge of the flange portion. The wind propulsion device according to claim 3 or 4.

6. The lower end of the lower cylindrical portion is positioned below the upper end of the main cylindrical portion in the vertical direction. The wind propulsion device according to claim 5.

7. The bracket further comprises a stepped portion that extends radially inward from the upper end of the main body cylindrical portion and then extends vertically upward, forming a stepped shape. The wind propulsion device according to claim 5.

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