Wind power generation device comprising low wind speed starting device for wind power generation device

Abstract

To allow operation of a wind power generation device even at a low wind speed.SOLUTION: A low wind speed starting device 300 for a wind power generation device is provided in a power transmission system from a wind turbine 100 to a power generator 600. The power transmission system comprises the wind turbine 100, a speed increaser 500, the power generator 600, and power transmission shafts PS1, PS2, and PS3 connecting them. The low wind speed starting device 300 for the wind power generation device is a torque converter 300. The torque converter 300 comprises a direct connection mechanism. An input shaft of the torque converter 300 is connected to a main shaft PS1 that is a power transmission shaft from the wind turbine 100. An output shaft of the torque converter 300 is connected to an input shaft PS2 of the speed increaser 500. Thereby, torque of rotation output from the wind turbine 100 is amplified and transmitted to the power transmission system.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a wind power generation device provided with a starting device for starting the wind power generation device even at low wind speeds.

Background Art

[0002] A wind power generation device is a device that rotates a windmill by receiving wind and connects a generator to the rotation shaft thereof to generate electricity. Therefore, in order to perform stable power generation and improve the operating rate of the generator, it is desirable that the windmill continuously rotates by making the most of the wind conditions (wind regime) at the location where the windmill is installed.

[0003] On the other hand, a wind power generation device cannot operate under any wind conditions in operation, and a cut-in wind speed and a cut-out wind speed are defined. When operating the windmill, it is necessary to have wind of at least the cut-in wind speed or higher. When the wind is strong, considering the strength of the windmill, etc., when the wind speed is higher than the cut-out wind speed, the rotation of the windmill is stopped or reduced.

[0004] Here, FIG. 1 is an example showing the wind regime at a certain location. As shown in FIG. 1, generally, the mode value of the average wind speed at a certain location is at a position much lower than the maximum wind speed at that location.

[0005] Therefore, although the cut-in wind speed of the windmill installed at such a wind regime location is usually set to a low wind speed, in order to start the generator connected to the windmill, a certain degree of rotation of the windmill is necessary. When the wind speed is low, since sufficient torque for rotating the generator by the windmill cannot be obtained, there is a limit to reducing the cut-in wind speed. For example, as shown in FIG. 1, in the case of a vertical axis windmill, the cut-in wind speed is about 4.5 (m / sec).

[0006] Therefore, in order to enable power generation even when the wind speed is low as described above, technologies such as the "wind power generation device" described in Japanese Patent Application Laid-Open No. 2008-45528 (Patent Document 1) and the "low wind speed wind power generation device" described in Japanese Patent Application Laid-Open No. 2015-505594 (Patent Document 2) are disclosed.

[0007] The technology disclosed in Patent Document 1 utilizes the magnetic force between permanent magnets as an auxiliary drive source for a wind power generation device when the wind is weak. Specifically, as described in FIG. 2 of Patent Document 1, "a central rotating portion 12 in which permanent magnets 12b are arranged at equal intervals and inclined with respect to the tangential direction thereof in a circular portion centered on the main shaft 30 for a generator, and another circular portion centered on a fixed shaft 13c outside the circular portion, a pair of outer small rotating portions 13 in which permanent magnets 13b are arranged at equal intervals and inclined with respect to the tangential direction thereof are provided", and "since the permanent magnets 12b and the permanent magnets 13b are inclined so that the like-pole surfaces face each other when approaching each other, they repel each other and try to separate. This force that tries to separate causes the central rotating portion 12 and the outer small rotating portions 13 to continuously rotate in a direction specified by a one-way clutch 13d" is described.

[0008] The technology disclosed in Patent Document 2 aims to "develop a wind power generation technology suitable for low wind speed characteristics of 2 to 6 (m / sec) so as to more effectively utilize wind power resources". As a solution, as described in FIG. 1 of Patent Document 2, "while configuring the blades in an upright or multi-stage block shape and forming an overlap region inside, an air resistance type blade is adopted, and an aerodynamic characteristic is configured in which the starting torque for rotating the blades of the wind turbine from a stopped state is large and the rotational moment is large, and an airfoil type blade is adopted outside to cause a fast rotational acceleration with a tip speed ratio of 1.0 or more" is described.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Patent Document 2

[0010] (1) However, in the technology described in Patent Document 1, since an auxiliary rotation mechanism using a permanent magnet is added to the windmill, there are drawbacks such as high cost and the need for additional space. In the medium and high wind speed range, there is also a drawback that the power generation efficiency decreases due to the electromotive force generated by the permanent magnet.

[0011] In addition, in the technology described in Patent Document 2, since a drag type blade is arranged on the central axis side of the windmill, the weight becomes excessive. Since an airfoil type blade is equipped on the outer edge side, there is a drawback that the wind flowing between the blades on the central axis side and the outer edge side interferes complicatedly and the noise also increases.

[0012] (2) On the other hand, when classifying the type of windmill according to the flow direction of the air flowing into the windmill, it is roughly classified into a so-called horizontal axis type windmill having a rotation axis (main axis) substantially parallel to the flow of the air flowing into the windmill, and a vertical axis type windmill having a main axis substantially perpendicular to the flow of the air flowing into the windmill. Among these, the vertical axis type windmill has the following characteristics and advantages for Japan in wind power generation, which is increasing rapidly towards the realization of a carbon-neutral society.

[0013] That is, compared with the horizontal axis type windmill, the vertical axis type windmill has the following advantages: (a) It rotates without the need for angle adjustment regardless of the wind direction, so it is suitable for Japan where the wind direction changes easily. (b) Since the blades extend in the vertical direction, a large ground contact area is not required, so it is suitable for Japan with a narrow land area. (c) The generator and main equipment can be installed on the ground, and maintenance is easy. (d) The blades can have a two-dimensional structure, and since angle adjustment with respect to the wind direction is not required, it is inexpensive. However, even with these advantages, the widespread adoption has not progressed because the starting wind speed is high, and for example, in areas with low wind speeds of about 4.5 (m / sec) or less as shown in FIG. 1, power generation does not occur. Thus, it is not possible to generate electricity at the most frequent wind speed on flat ground in Japan, and a profitable amount of power generation cannot be ensured.

[0014] (3) Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to provide a wind power generation device equipped with a low wind speed starting device for a wind power generation device that enables the operation of the wind power generation device even at low wind speeds and can further be used for a vertical axis windmill.

Means for Solving the Problems

[0015] To solve the above problems, the present invention relates to a wind power generation device equipped with a low wind speed starting device for a wind power generation device, and a low wind speed starting device for a wind power generation device is provided in the power transmission system from the windmill to the generator. The power transmission system is composed of the windmill, a speed increaser, a generator, and a power transmission shaft connecting each of them. The low wind speed starting device for a wind power generation device is a torque converter, and the torque converter is provided with a direct connection mechanism. The input shaft of the torque converter is connected to the main shaft, which is the power transmission shaft from the windmill, and the output shaft of the torque converter is connected to the input shaft of the speed increaser. Thus, the torque of the rotational output from the windmill is amplified and transmitted to the power transmission system. A wind power generation device equipped with a low wind speed starting device for wind power generation is provided.

[0016] Further, to solve the above problems, the direct connection mechanism is a centrifugal lock-up clutch provided inside the outer shell of the torque converter, or the torque converter is provided with a centrifugal brake mechanism on its outer periphery. The centrifugal brake mechanism includes a case for housing the torque converter, an elastic body having one end connected to the outer shell of the torque converter, and a brake shoe and a brake lining connected to the other end of the elastic body. The case is fixed inside the housing of the wind power generation device. By using the inner peripheral surface of the outer shell of the torque converter as the friction surface of the centrifugal lock-up clutch and the outer peripheral surface of the outer shell of the torque converter as the support surface of the elastic body of the centrifugal brake mechanism, compactness is achieved by integrating components. When the elastic body extends due to the rotation of the torque converter, the brake lining contacts the inner surface of the case, suppressing or stopping the rotation of the torque converter. Or, the torque converter is any one of a three-element one-stage type, a four-element one-stage type, a four-element two-stage type, or a six-element three-stage type. Or, instead of the direct connection mechanism, by making the vane opening of the stator of the torque converter movable or by providing a one-way clutch, or by using a vertical-axis windmill, the above problems can be more effectively solved.

Advantages of the Invention

[0017] In the present invention, since the power transmission system of the windmill is provided with a low wind speed starting device for a wind power generation device, the wind power generation device can operate even at low wind speeds, and efficient operation of the windmill is possible even under low wind speed conditions. Further, by using this for a vertical-axis windmill, wider utilization is possible.

[0018] Also, in the present invention, by providing a direct connection mechanism such as a centrifugal lock-up clutch 340 in relation to the torque converter 300, more efficient operation of the windmill is possible according to various wind conditions. In addition, when a centrifugal brake mechanism is incorporated into the low wind speed starting device for wind power generation according to the present invention, without providing a separate and independent expensive brake system, by using the inner peripheral surface of the outer shell of the torque converter (as the low wind speed starting device for wind power generation) as the friction surface of the centrifugal lock-up clutch and the outer peripheral surface of the outer shell of the torque converter as the support surface of the elastic body of the centrifugal brake mechanism, it is possible to achieve compactification by integrating components. With an inexpensive and compact system, even when the windmill reaches the cut-out wind speed, it is possible to prevent damage to the windmill and the generator due to gusts or strong winds.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0020] Hereinafter, a wind power generation device equipped with a low wind speed starting device for a wind power generation device according to the present invention will be described more specifically with reference to the drawings.

[0021] It should be noted that the drawings referred to below illustrate the outline of the present invention, and in some cases, for ease of understanding, some details of the structure, ratio, notation of common structures, etc. are emphasized or omitted and shown schematically, and the hatching is also shown with priority given to ease of understanding.

[0022] In the present invention, for example, even in a low wind speed condition where the wind speed is about 4.5 (m / sec) or less, by using a low wind speed starting device for a wind power generation device in the power transmission system from the windmill, the rotational torque from the main shaft of the windmill is amplified, enabling power generation by the generator. Therefore, the overall configuration of the system of a wind power generation device equipped with a low wind speed starting device for a wind power generation device according to the present invention is, for example, as shown in FIG. 2, a windmill 100, a power transmission shaft (main shaft) PS1 from the windmill, a switching mechanism 200 connected thereto, a low wind speed starting device 300 for a wind power generation device, a power transmission shaft PS2 from the low wind speed starting device 300 side, a speed increaser 500 connected thereto, a power transmission shaft PS3 from the speed increaser 500, and a generator 600 connected thereto. (Note that the above switching mechanism 200 is selectively provided according to the configuration of the direct connection mechanism described later.) And since these power transmission systems from the windmill start from the windmill 100 and reach the generator 600, hereinafter, the description will be given in sequence along this line.

[0023] (1) First, the windmill 100 to which the present invention can be applied is basically a device that receives wind with one or a plurality of blades (vanes) 110 and rotates the main shaft PS1, and the blade 110 and the main shaft PS1 are connected via a spoke 130 and a hub 150. And such a windmill is roughly classified into a horizontal axis type windmill and a vertical axis type windmill as described above, and is divided into a lift type and a drag type from the operating principle with respect to the blade 110.

[0024] When comparing a horizontal-axis wind turbine and a vertical-axis wind turbine, generally, a horizontal-axis wind turbine requires yaw control to align the direction of the blade rotation plane according to the wind direction. However, since the blade pitch can be changed, it is easy to control the rotation speed according to the wind speed, and it has advantages such as being easy to scale up and obtain large output.

[0025] On the other hand, since a vertical-axis wind turbine has no wind direction dependence, it does not require yaw control like a horizontal-axis wind turbine. However, in practical terms, since the chord line of the blade is fixed and it has a structure that cannot perform pitch control, it is difficult to control the speed according to the wind speed, and it also has characteristics such as being difficult to self-start in some cases.

[0026] Also, a lift-type wind turbine rotates the blade by utilizing the lift acting on the blade, and a drag-type wind turbine rotates the blade by utilizing the drag received by the blade.

[0027] Generally, in a lift-type wind turbine, it is possible to increase the rotation speed of the wind turbine, but the obtained torque is small. In contrast, in a drag-type wind turbine, the rotation speed of the wind turbine cannot exceed the wind speed, but it is possible to increase the torque.

[0028] In the present invention, it is possible to use either a horizontal-axis wind turbine or a vertical-axis wind turbine, or a lift-type or a drag-type. Each type of wind turbine has characteristics specific to each individual type, and by taking advantage of these characteristics, it is possible to configure a wind power generation device equipped with a low wind speed starting device for a wind power generation device according to the present invention.

[0029] Therefore, it may be connected to a wind turbine with a relatively small torque but a large rotation speed to increase the torque of the power transmission shaft with a high rotation speed, or it may be connected to a wind turbine with a relatively large torque but a small rotation speed to further increase the torque.

[0030] However, in the configuration example of FIG. 2 according to the present invention, as an example of the windmill 100, a gyro-mill type vertical-axis windmill is illustrated in the drawing. The gyro-mill type vertical-axis windmill is a lift type vertical-axis windmill. As described above, although the rotational speed can be increased, the rotational torque is small. Therefore, by increasing the torque obtained by the low wind speed starting device for a wind power generation device according to the present invention, it can be utilized more effectively.

[0031] Next, the power transmission system of the windmill that can use the present invention is basically a transmission system configured to transmit the power from the windmill on the path from the windmill 100 to the generator 600. (2) Among these, the main shaft PS1 of the windmill 100 is a rotating shaft to which the rotation of the windmill 100 is transmitted via the hub 150 that supports the blade 110 of the windmill 100. Generally, on the same axis as this rotating shaft, other components such as a speed increaser 500, a brake mechanism (not shown), and a generator 600 are arranged. These are connected by the input / output shafts (PS1, PS2, PS3) to each device, and power transmission is performed. (Note that hereinafter, these input / output shafts may represent the input / output mainly based on the component being focused on. Therefore, for example, the output shaft PS1 (main shaft) from the windmill 100 becomes the input shaft PS1 when viewed from the starting device 300 side.) And these devices are generally arranged and fixed inside the housing to protect them from the external environment and suppress the leakage of noise, etc. to the outside. In the case of a horizontal-axis windmill, such a housing is called a nacelle and is provided on the upper part of a tower or pole, and direction control (yaw control) is performed according to the direction of the wind.

[0032] On the other hand, in the case of a vertical-axis windmill, since the housing for accommodating these devices does not require rotation according to the wind direction like a horizontal-axis windmill, it is possible to stably arrange heavy objects such as generators at a position with a low center of gravity by fixing them, and there are also examples installed on the roof or side wall of a building.

[0033] In addition, in the configuration example of FIG. 2, the low wind speed starting device 300 for a wind power generation device according to the present invention is provided between the main shaft PS1 of the windmill 100 and the speed increaser 500 after being connected via the switching mechanism 200 in the above-described power transmission system. Particularly, in the case of a wind power generation system using the speed increaser 500, the motor cogging torque and the inertia on the motor side increase due to the speed increasing gears constituting the speed increaser, and the starting torque increases. Therefore, the present invention is more effective.

[0034] However, in the present invention, it is not limited to such a configuration, and it is also possible to provide the low wind speed starting device 300 for a wind power generation device between the speed increaser 500 downstream of the output shaft PS1 of the windmill 100 and a brake mechanism (not shown), or between a brake mechanism (not shown) and the generator 600. As described above, in the present invention, it is possible to arrange the most efficient configuration specifically according to the type of the windmill 100 using the present invention, the type of the speed increaser 500, the type of the generator 600, and the like.

[0035] (3) Next, the low wind speed starting device 300 for a wind power generation device used in the present invention is a device having a torque amplification function that can amplify and output the input rotational torque. (a) In the present invention, a torque converter 300, which is a kind of fluid coupling, is used as such a device, and its structure is, for example, as shown in FIG. 3.

[0036] Here, FIG. 3 shows an example of the torque converter 300 arranged along the main shaft PS1 of the windmill. FIG. 3(A) is a cross-sectional view when the torque converter 300 is viewed from a direction perpendicular to the main shaft PS1, and FIG. 3(B) is a schematic view when the torque converter 300 is viewed along the direction of the power transmission shaft PS2 from the position of the K-K line in FIG. 3(A).

[0037] The example of the torque converter 300 shown in FIG. 3 is a three-element single-stage type used in an automatic transmission for an automobile or the like. The torque converter 300 is composed of a pump impeller 311, a turbine liner 330, and a stator 350, which are provided inside an annular outer shell 310 and are arranged coaxially with the main shaft PS1 of the windmill.

[0038] And the inside of the outer shell 310 is filled with a working fluid (fluid) FL (not shown). The pump impeller 311 causes the working fluid FL to flow and press the turbine liner 330. The discharge flow from the turbine liner 330 is rectified by the stator 350 and circulates between the pump impeller 311 to amplify the torque.

[0039] More specifically, the pump impeller 311 is composed of a plurality of blade-shaped elements that can rotate around the output shaft PS2 of the torque converter 300. The pump impeller 311 is configured on the inner side of the outer shell 310 of the torque converter on the output shaft PS2 side, facing the direction of the windmill 100. The main shaft PS1 from the windmill is connected to the windmill side of the outer shell 310, and the rotation of the main shaft PS1 causes the pump impeller 311 to rotate together with the outer shell 310.

[0040] Also, the turbine liner 330 is composed of a plurality of blade-shaped elements provided opposite to the pump impeller 311. The turbine liner 330 rotates by receiving the flow of the working fluid FL driven by the pump impeller 311, and the rotation can be taken out from the output shaft PS2 of the torque converter 300 connected to the central part side of the turbine liner 330.

[0041] The stator 350 is a rectifying plate (fixed vane) provided between the pump impeller 311 and the turbine liner 330, and is fixed on a cylindrical shaft CS2 on which the output shaft PS2 of the torque converter 300 is rotatably provided inside. The cylindrical shaft CS2 is connected and fixed to the housing of the windmill.

[0042] Also, the working fluid FL is generally a mineral oil called "Automatic Transmission Fluid" for vehicles and the like, and a substance with relatively low viscosity and strong resistance to temperature changes is used.

[0043] Therefore, in the torque converter 300 having the above-described configuration, when the main shaft PS1 of the windmill 100 rotates, the outer shell 310 of the torque converter 300 connected thereto rotates, and the pump impeller 311 provided inside the outer shell 310 rotates. Then, due to the rotation of the pump impeller 311, the working fluid FL flows so as to press the turbine liner 330, and the output shaft PS2 of the torque converter 300 connected to the center side of the turbine liner 330 rotates. And thus, the working fluid FL that has rotated the turbine liner 330 is circulated in the direction of the pump impeller 311 via the stator 350, and is further accelerated as the main shaft PS1 of the windmill 100 rotates, and then again acts so as to press the turbine liner 330 in the direction thereof.

[0044] Therefore, with these mechanisms, it is possible to extract an output with increased torque from the output shaft PS2 of the torque converter 300. Therefore, by using the torque converter 300 that operates in this way, in the present invention, it is possible to amplify the torque from the main shaft PS1 of the windmill 100 and output it to the downstream power transmission system.

[0045] (b) Also, in the example of the torque converter 300 described above, the rotational speed of the turbine liner 330 increases as the rotational speed of the pump impeller 311 increases. Generally, however, the efficiency decreases due to the stator 350 becoming a resistance in the region of the speed ratio just before the rotational speed of the turbine liner 330 increases and becomes equal to the rotational speed of the pump impeller 311, and the torque ratio gradually becomes 1 or less. Therefore, in order to prevent a decrease in efficiency and torque ratio in such a case, it is also possible to provide a direct connection mechanism (not shown) so as to function at a predetermined rotational speed (lock-up speed).

[0046] Here, the direct connection mechanism is a mechanism that directly transmits the power from the main shaft to the transmission when the torque of the main shaft increases due to the rotation of the windmill itself. As such a mechanism, for example, in the present invention, it can be performed via a device provided separately while cooperating with the torque converter, or via a centrifugal lock-up clutch provided inside the torque converter.

[0047] Therefore, when directly connecting via a device (mechanism) provided separately from the torque converter as the direct connection mechanism, for example, as shown in FIG. 2, an electronic or mechanical switching mechanism 200 is inserted into the power transmission shaft PS1, and it operates in cooperation according to the speed ratio between the rotational speed of the input shaft PS1 and the rotational speed of the output shaft PS2 in the torque converter 300, etc., to switch the power transmission path, and the output of the output shaft PS1 of the windmill 100 can be directly connected to a downstream speed increaser 500, etc.

[0048] Also, when providing a centrifugal lock-up clutch inside the torque converter as the direct connection mechanism, for example, by eliminating the switching mechanism 200 as shown in FIG. 2, a configuration using a torque converter 300 incorporating a centrifugal lock-up clutch 340 as shown in FIGS. 4 and 5 including FIG. 3 described above is possible.

[0049] That is, as shown in FIG. 3, the centrifugal lock-up clutch 340 is provided on a lock-up plate 341 connected to the side surface along the axial direction of the turbine liner 330. One end is connected to the lock-up plate 341 and it consists of a first return spring (elastic body) 343 that extends as the turbine liner 330 rotates, a first brake shoe 345, and a first brake lining (friction material) 347.

[0050] One end of the other elastic body 343 is connected to the first brake shoe 345, and a first brake lining 347 is provided on the outer peripheral surface of the first brake shoe 345. Therefore, by adopting such a structure, the first brake shoe 345 and the first brake lining 347 function as a mass (weight) that contributes to the elongation of the elastic body 343 by the centrifugal force acting in the normal direction from the power transmission shaft when receiving the rotation of the turbine liner 330 by summing these two masses (although the first brake shoe 345 has the main mass).

[0051] Therefore, the centrifugal lock-up clutch 340 adjusts in advance the elasticity of the first return spring 343, the mass of the first brake shoe 345 and the first brake lining 347 (mass), etc., so that at low wind speeds, as shown in FIGS. 3(A) and (B), the centrifugal force due to the mass accompanying the rotation of the turbine liner 330 is smaller than the force in the direction of the main shaft PS1 by the first return spring 343, and the first brake lining (friction material) 347 is configured to be separated from the inside of the outer shell 310 to which the pump impeller 311 is connected, making it possible to be in a non-lock-up state (a state where the rotation of the pump impeller 311 is not directly transmitted to the turbine liner 330).

[0052] On the other hand, at medium wind speeds, as shown in FIGS. 5(A) and (B), the centrifugal lock-up clutch 340 is configured such that the centrifugal force due to the mass caused by the rotation of the turbine liner 330 is greater than the force in the direction of the main shaft PS1 by the first return spring 343, and the first brake lining (friction material) 347 is pressed against the inside of the outer shell 310 to which the pump impeller 311 is connected, making it possible to be in a lock-up state (a state where the rotation of the pump impeller 311 is directly transmitted to the turbine liner 330).

[0053] In the present invention, the classification of low wind speed, medium wind speed, and high wind speed is not necessarily strict. However, in the wind conditions at the location where the windmill is installed, for example, the wind speed up to the maximum wind speed can be divided into three wind speed regions with equal or arbitrary widths for each wind speed magnitude and classified. Also, in the description of the centrifugal brake mechanism to be described later, the medium wind speed is given as an example of the speed at which the centrifugal lock-up mechanism to be described later is operating, but it is not necessarily limited to this.

[0054] (C) Next, in the low wind speed starting device 300 for a wind power generation device according to the present invention, as shown in FIGS. 6 to 8, it is also possible to provide a centrifugal brake 370 to have a braking function.

[0055] That is, in a wind power generation device, when the wind speed increases due to gusts or typhoons, etc., in order to prevent damage to the windmill, generator, etc. due to excessive rotation, a brake mechanism is provided and a structure for suppressing over-rotation is adopted.

[0056] Such a brake mechanism can be provided on the main shaft of the windmill or at various locations of the power transmission mechanism, and it is also possible to adopt such a structure in the present invention. However, in the present invention, it is further possible to adopt a structure in which a centrifugal brake 370 is provided in the torque converter 300 as a low wind speed starting device for a wind power generation device.

[0057] More specifically, as shown in FIGS. 7(A) and (B), the centrifugal brake 370 according to the present invention includes a case 390 that houses the torque converter 300 main body, an elastic body (second return spring) 373 having one end connected to the outer shell 310 of the torque converter 300, a second brake shoe 375 to which the other end of the elastic body 373 is connected, and a friction material (second brake lining) 377 provided on the outer peripheral side surface of the second brake shoe.

[0058] And these components may adopt a configuration in which they are held by appropriate holders or connectors (not shown) so as not to shift in a direction other than the radial direction.

[0059] Therefore, the centrifugal brake mechanism 370 can function as a mass (weight) that contributes to the elongation of the second return spring 373 due to inertia by receiving the rotation of the outer shell 310 of the torque converter and causing the second brake shoe 375 and the second brake lining 377 to move, similar to the case of the centrifugal lock-up clutch 340 described above, by adjusting in advance the elasticity of the second return spring 373, the mass of the second brake shoe 375 and the second brake lining 377, and the like.

[0060] Therefore, when the outer shell 310 of the torque converter 300 is rotating at medium wind speed, as shown in FIGS. 7(A) and (B), the centrifugal force (the force directed radially outward of the outer shell 310 of the torque converter 300) due to the mass caused by the rotation of the outer shell 310 of the torque converter 300 is made smaller than the force in the power transmission shaft direction (the force directed radially inward of the outer shell 310 of the torque converter 300) by the second return spring 373, so that the friction material (the second brake lining 377) is configured to move away from the inside of the case 390 that houses the torque converter 300, and it is possible to keep the brake off.

[0061] On the other hand, at high wind speed, as shown in FIGS. 8(A) and (B), the centrifugal brake mechanism 370 is configured such that the centrifugal force due to the mass caused by the rotation of the outer shell 310 of the torque converter 300 is made larger than the force in the power transmission shaft PS1 direction by the second return spring 373, so that the friction material (the second brake lining) 377 is pressed against the inner peripheral surface side of the case 390 that houses the torque converter 300 main body, and by using the inner peripheral surface side of the case 390 as a brake drum, it is possible to apply a brake to the power transmission from the main shaft PS1. In the examples shown in FIGS. 7 to 8, four sets of the centrifugal brake mechanism 370 are provided on the outer periphery of the torque converter. However, including the examples described from FIGS. 10 to 12 to be described later, these are merely examples, and one set or a plurality of two or more sets may be provided.

[0062] (4) Next, it is possible to provide a speed increaser 500 in the power transmission system from the windmill 100. As shown in FIG. 2 or FIG. 4, such a speed increaser 500 increases the rotational speed of the rotational output input from the speed increaser side input shaft PS2 and outputs it from the speed increaser side output shaft PS3. And, generally, a gear mechanism such as a planetary gear is used for such a speed increaser 500, but in the present invention, since there is no particular limitation on the form, any form can be adopted, and the speed increaser side input shaft PS2 may be directly used as the output shaft PS1 of the windmill arranged in the previous stage.

[0063] Also, in the present invention, when a torque converter 300 as the low wind speed starting device for the wind power generation device is connected to the output shaft PS1 of the windmill, it is also possible to directly use the output shaft PS2 of the torque converter 300 as the speed increaser side input shaft PS2. In that case, as in the case of being used in a vehicle, it is also possible to integrate the torque converter 300 and the speed increaser 500 and house them in a single case to make it more compact.

[0064] (5) Next, the generator 600 is a device that finally receives power from the windmill 100 and converts the rotational motion input from the generator side input shaft PS3 into electricity. Therefore, the types of generators 600 used in wind power generation devices generally include induction generators, synchronous generators, permanent magnet generators, etc. However, in the present invention, there is no particular limitation on the type as long as the rotational power can be converted into electric power.

[0065] Note that the electric power generated by the generator 600 is either consumed for self - use or connected to the grid and incorporated into commercial power for distribution to the consumption area. Also, when the windmill is used for purposes other than power generation, it is possible to connect various converters as needed.

[0066] (6) According to the "wind power generation device equipped with a low wind speed starting device for wind power generation devices" of the present invention with the above configuration, by using a torque converter as the low wind speed starting device, the wind power generation device can operate even at low wind speeds, and efficient operation of the windmill is possible even in low wind speed wind conditions.

[0067] Further, in the present invention, by providing a direct connection mechanism such as a centrifugal lock-up clutch 340 in relation to the above torque converter 300, more efficient operation of the windmill is possible according to various wind conditions. Also, when a centrifugal brake mechanism 370 is incorporated into the outer shell 310 of the torque converter 300, without providing a separate and expensive brake system, by using the inner peripheral surface of the outer shell of the torque converter (as a low wind speed starting device for wind power generation) as the friction surface of the centrifugal lock-up clutch and the outer peripheral surface of the outer shell of the torque converter as the support surface of the elastic body of the centrifugal brake mechanism, compactification is achieved by integrating the components, and with an inexpensive and compact system, it is possible to prevent damage to the windmill and generator due to gusts or strong winds even when the windmill reaches the cut-out wind speed.

[0068] (7) It should be noted that the above-described configuration example of the present invention shows an example of the configuration of the present invention, and within the scope of the gist of the present invention, each component can be arbitrarily replaced or changed. (a) Therefore, in the above-described configuration example, as an example of a vertical axis windmill, a gyro mill type windmill was exemplified, but it is not limited to this, and any of a Darrieus type, a straight blade type, a Savonius type, a paddle type, a cross flow type, etc. may be used, or a propeller type, a Dutch type, a multi-blade type, a sail type, etc., which are horizontal axis windmills, may also be used. (b) Further, in the above-described configuration example, as the device having a torque amplification function, a torque converter 300, which is a type of fluid coupling, is used, and a three-element single-stage torque converter having three elements, i.e., a pump impeller 311 (pump), a turbine blade (turbine), and a stator 350, is used. However, a four-element single-stage torque converter in which the stator (not shown) is divided into two parts, a four-element two-stage torque converter using two turbines T1 and T2 as shown in Fig. 9(A), or a six-element three-stage torque converter using three turbines T1, T2, and T3 and two stators S1 and S2 as shown in Fig. 9(B) can also be used.

[0069] And including that case, the torque converter, as will be described later, does not necessarily have to be limited to those equipped with a direct connection mechanism.

[0070] Therefore, by using these multi-stage torque converters, it is also possible to improve the torque ratio and maximum efficiency of the torque converter at rotational speeds in a wide range.

[0071] Also, in the above-described configuration example, one torque converter is used. However, it is also possible to prepare a plurality of torque converters with different characteristics in series or in parallel and use them in combination or switch between them according to the input speed range, etc. Therefore, for example, when a plurality of torque converters with different characteristics are prepared in parallel, it is also possible to adopt a configuration in which they are switched and used by using a switching mechanism as shown in Fig. 2.

[0072] (c) Further, in the above torque converter, a fixed stator 350 is used. However, instead of the above-described direct connection mechanism, it is also possible to use an existing mechanism to make the blade opening degree of the stator 350 movable, or to adopt a structure provided with a one-way clutch. That is, when the vane opening of the stator 350 is made movable in this way, when the stator 350 starts to become a resistance to the working fluid FL, it is also possible to adopt a structure in which the vane opening is adjusted to reduce the resistance and prevent the torque ratio from decreasing. Also, when a one-way clutch is provided, similarly, when the stator 350 starts to become a resistance to the working fluid FL, the clutch disengages and the stator 350 can rotate in the same direction as the pump impeller 311, preventing the stator 350 from becoming a resistance. The one-way clutch mechanism can be realized by existing means. For example, a structure can be adopted in which a one-way clutch that can rotate only in one direction is provided between the stator 350 and a cylindrical shaft CS2 around the output shaft PS2 where the stator 350 is arranged.

[0073] (B) Also, when the centrifugal lock-up clutch mechanism 340 is operating, a damper mechanism may be provided in the torque converter 300 by any means to suppress the generation of surge current or the like from the generator 600 due to a sudden change in the rotational speed of the main shaft PS1.

[0074] (E) Also, in the above-described configuration example, as an example of the centrifugal brake 370, an example is described in FIGS. 7 and 8 in which one end of an elastic body 373 is connected to the outer shell 310 of the torque converter 300, and the other end of the elastic body 373 is connected to a mass (weight) composed of a second brake shoe 375 and a second brake lining 377. Therefore, based on the same technical concept, for example, as shown in FIG. 10, after arranging a plurality of masses (the third brake shoe 775 and the third brake lining 777) around the torque converter 300, a part of the mass is connected to the outer shell 310 of the torque converter via a hinge H to form a brake, or as shown in FIG. 11, an appropriate connector 871 is connected between the hinge H and a plurality of masses (the fourth brake shoe 875 and the fourth brake lining 877). It is also possible to adopt a configuration, or as shown in FIG. 12, using both ends of a plurality of springs (elastic bodies) SP to connect a plurality of masses (the fifth brake shoe 975 and the fifth brake lining 977) to each other and configure them to surround the torque converter 300.

[0075] Among these, the example described in FIG. 10 rotatably attaches one end of the third brake shoe 775 to the outer shell 310 of the torque converter 300 via an appropriate hinge H, and the other end of the third brake shoe 775 is in the circumferential direction of the outer shell 310 of the torque converter 300, in the forward direction when viewed from the rotation direction of the output shaft PS2 (when rotating counterclockwise as shown by the bold arrow in the figure, it is in the counterclockwise position), and is connected to the other end of the third return spring (elastic body) 773 whose one end is connected to the outer shell 310.

[0076] And on the side where the elastic body 773 of the third brake shoe 775 is connected, a third brake lining 777 is provided on its outer surface facing the inner side of the case 390, and it is configured to be slidable with the inside of the case 390.

[0077] Therefore, with such a configuration, at medium wind speeds, as shown in Fig. 10(A), the mass consisting of the third brake shoe 775 and the third brake lining 777 is located on the outer shell 310 side of the torque converter 300 and no braking action occurs. However, at high wind speeds, as shown in Fig. 10(B), as a result of the elongation of the elastic body 773, the third brake lining 777 on the outer peripheral side surface of the third brake shoe 775 is pressed against the inside of the case 390 and slides, generating a braking action, thereby making it possible to suppress or stop the rotation of the output shaft PS2 from the torque converter 300. (In this case, an aerodynamic form may be added to the brake shoe 775 so that, in addition to centrifugal force, air resistance in the rotational direction is also used in combination for the elongation of the elastic body 773.) Also, the example shown in Fig. 11 basically has the same structure as Fig. 10, but a connector 871 is connected between the hinge H and the fourth brake shoe 875, and the locking portion JP between the fourth brake shoe 875 and the connector 871 is configured to be slidable along the connector 871. And by means of such a connector 871, it is also possible to concentrate the mass on the portion of the fourth brake shoe 875 to which the elastic body 873 is connected, improving the response to centrifugal force due to rotation. Therefore, also in this case, similar to the structural example of Fig. 10, at medium wind speeds, as shown in Fig. 11(A), the mass consisting of the fourth brake shoe 875 and the third brake lining 877 is located on the outer shell 310 side of the torque converter 300 and no braking action occurs. However, at high wind speeds, as shown in Fig. 11(B), as a result of the elongation of the elastic body 873, the fourth brake lining 877 on the outer peripheral side surface of the fourth brake shoe 875 is pressed against the inside of the case 390 and slides, resulting in a braking action.

[0078] Further, the example described in FIG. 12 shows an example in which a mass composed of a plurality of fifth brake shoes 975 and fifth brake linings 977 is arranged so as to surround the torque converter 300, the masses are connected to each other by a spring (elastic body) SP, and appropriate holders 971 are arranged on both sides along the shaft PS1 to prevent displacement of these masses.

[0079] Therefore, when such a configuration is adopted, at medium wind speeds, as shown in FIG. 12(A), the fifth brake shoes 975 and the fifth brake linings 977 are located closer to the outer shell 310 of the torque converter 300. However, at high wind speeds, as shown in FIG. 12(B), due to centrifugal force, the mutual distance between the masses composed of the fifth brake shoes 975 and the fifth brake linings 977 increases, and as a result, the elastic body SP stretches. Then, the fifth brake lining 977 on the outer peripheral surface of the fifth brake shoe 975 is pressed against the inside of the case 390 and slides to act as a brake, so that the rotation of the output shaft PS2 of the torque converter 300 can be suppressed or stopped.

Explanation of Signs

[0080] 100 Windmill 110 Blade 130 Spoke 150 Hub 200 Switching mechanism 300 Low wind speed starting device for wind power generation 310 Outer shell 311 Pump impeller 330 Turbine liner 340 Centrifugal lock-up clutch 341 Lock-up plate 343 First return spring (elastic body) 345 First brake shoe 347 First brake lining 350 Stator 370 Centrifugal brake 373 Second return spring (elastic body) 375 Second brake shoe 377 Second brake lining 390 Case 500 Speed increaser 600 Generator 773 Third return spring (elastic body) 775 Third brake shoe 777 Third brake lining 871 Connector 873 Fourth return spring (elastic body) 875 Fourth brake shoe 877 Fourth brake lining 971 Retainer 975 Fifth brake shoe 977 Fifth brake lining PS1, PS2, PS3 Power transmission shaft CS2 Cylindrical shaft FL Working fluid H Hinge SP Spring (elastic body) JP Locking part between the fourth brake shoe and the connector

Claims

1. A wind power generation device equipped with a low wind speed starting device for a wind power generation device, wherein the low wind speed starting device for a wind power generation device is provided in the power transmission system from the wind turbine to the generator, the power transmission system is composed of the wind turbine, a speed increaser, a generator, and a power transmission shaft connecting each of them, the low wind speed starting device for a wind power generation device is a torque converter, and the torque converter is provided with a direct connection mechanism, the input shaft of the torque converter is connected to the main shaft which is the power transmission shaft from the wind turbine, and the output shaft of the torque converter is connected to the input shaft of the speed increaser, whereby the torque of the rotational output from the wind turbine is amplified and transmitted to the power transmission system, and it is characterized in that it is a wind power generation device equipped with a low wind speed starting device for wind power generation.

2. The wind power generation device equipped with the low wind speed starting device for wind power generation according to claim 1, wherein the direct connection mechanism is a centrifugal lock-up clutch provided inside the outer shell of the torque converter.

3. The torque converter is provided with a centrifugal brake mechanism on the outer periphery, the centrifugal brake mechanism is composed of a case for housing the torque converter, an elastic body having one end connected to the outer shell of the torque converter, and a brake shoe and a brake liner connected to the other end of the elastic body, the case is fixed inside the housing of the wind power generation device, by using the inner peripheral surface of the outer shell of the torque converter as the friction surface of the centrifugal lock-up clutch and the outer peripheral surface of the outer shell of the torque converter as the support surface of the elastic body of the centrifugal brake mechanism, compactification is achieved by integrating components, when the elastic body extends due to the rotation of the torque converter, the brake liner contacts the inner surface of the case, and the rotation of the torque converter is suppressed or stopped, The wind power generation device equipped with the low wind speed starting device for wind power generation according to claim 2.

4. The wind power generation device equipped with the low wind speed starting device for wind power generation according to claim 1, wherein the torque converter is any one of a three-element one-stage type, a four-element one-stage type, a four-element two-stage type, or a six-element three-stage type torque converter.

5. The wind power generation device equipped with the low wind speed starting device for wind power generation according to claim 1, wherein instead of the direct connection mechanism, the blade opening degree of the stator of the torque converter is made movable, or a one-way clutch is provided.

6. The windmill is a vertical-axis windmill, and the wind power generation device includes the low wind speed starting device for wind power generation according to any one of claims 1 to 5.

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