Foldable windmill

Abstract

To solve such a problem with a vertical axis windmill as strength design at the time of being subjected to a strong wind to prevent an accident such as rupture and collapse and dullness of a windmill which is caused by setting an excessive design strength, thereby achieving cost reduction and significantly improving practicality.SOLUTION: A foldable windmill is provided with a bendable hinge 10 installed in an intermediate part of a rotor that is long in a span direction and has such a structure that the hinge allows an upper blade 11 and a lower blade 9 to be oriented in parallel with a circumferential direction of a windmill rotary shaft 1.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an apparatus for utilizing wind energy, and particularly to a foldable windmill characterized in that the entire rotating part has a foldable structure in a windmill having a structure in which the span is substantially parallel to the rotation axis.

Background Art

[0002] Currently, windmills that have been put into practical use are roughly classified into two types: horizontal-axis type and vertical-axis type. The former is composed of a rotation axis extending in the horizontal direction as a so-called propeller type and a propeller attached thereto, and the latter is composed of a rotation axis substantially in the vertical direction and a rotating blade whose span extends substantially parallel thereto. The present invention relates to the latter, and aims to enhance the practicality of the windmill.

[0003] Vertical-axis windmills are generally used as a means for providing inexpensive products because of their simple structure, and research aiming at enhancing performance and practicality has not been sufficiently conducted. Therefore, the study of an important issue, wind resistance, that is, how much wind speed should be withstood, is also not sufficient. The present invention provides an answer to the standard of practical strength calculation, which is a major issue in the entire current windmill technology. This problem cannot give an accurate answer when discussing how strong a windmill should be designed to withstand in the first stage of windmill design. Currently, based on past experience, the maximum wind speed at the installation location is estimated and the design is made accordingly. However, at present when the climate change is intensifying, there are many events that overturn the common sense so far. On the other hand, making a robust windmill with a large safety factor leads to providing a heavy windmill using excessive materials in practice, which is not preferable economically and industrially. The key to solving this problem is to fold the windmill itself when the wind speed exceeds a certain level, thereby reducing the large wind resistance load applied to the windmill by strong winds. Currently, in the horizontal-axis windmill described above, a method of reducing the wind resistance load by aligning the pitch angle of the rotor blades (propellers) parallel to the direction of the wind is adopted. However, in reality, damage accidents of the blades and struts have occurred, and it is known that this method alone is insufficient. Clearly, a more precise technology for avoiding wind pressure resistance is needed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] The present invention divides a rotor blade that is long in the span direction into an upper blade and a lower blade by providing a hinge that can be bent at the middle part, and the hinge can direct the upper blade and the lower blade parallel to the circumferential direction of the windmill rotation axis. The present invention relates to a folding windmill having such a structure. The rotation axis of the windmill itself does not extend to a high position, and vibrations and sounds caused by strong winds can also be suppressed. The present invention provides a technology that can solve almost all problems arising from a vertical-axis windmill during strong winds.

Problems to be Solved by the Invention

[0006] The problem to be solved by the present invention is to solve the problems related to the strength design of a vertical-axis windmill during strong winds, prevent accidents such as damage and collapse, prevent the windmill from becoming heavy due to excessive setting of the design strength, and as a result, achieve cost reduction and significantly expand practicality.

Means for Solving the Problem

[0007] Specifically, the means for solving the above problems of the present invention is to provide a foldable windmill having a structure in which a long rotating blade in the span direction is divided into an upper blade and a lower blade by providing a hinge that can be bent at the middle part, and the upper blade and the lower blade can be oriented in parallel in the circumferential direction of the windmill rotation axis by the hinge. The rotation axis of the windmill itself does not extend to a high position, and vibration and noise generation can be suppressed by strong winds, providing a technology that can solve almost all problems arising from a vertical axis windmill during strong winds. Furthermore, the foldable windmill of the present invention is also effective in preventing the rotation axis from getting in the way even when it is necessary to pass under a bridge when a large windmill is being manufactured and when entering or leaving a port. The structure and operation will be described below. The structure of the vertical axis windmill of the present invention is provided with a plurality of support arm members on a fixed hub member fixed to the rotation axis, and a movable arm member that can swing in the vertical direction on a rotation hub member rotatably provided on the rotation axis. A plurality of lower rotating blades that are long in the span direction are provided at the tip ends of the support arm member and the movable arm member via a first universal hinge and a second universal hinge, respectively. An upper blade is provided at the upper end of the lower rotating blade via a rotatable hinge that can be bent. When the rotatable hinge extends, the upper blade becomes substantially in a straight line with the lower blade member, and when the rotatable hinge bends, it is in a state of being bent by about 90°. Furthermore, a polygonal support member is provided near the tip end of the upper blade via a third universal hinge. Other upper blades are coupled to each corner of the support member via other third universal hinges. When the rotation hub of the windmill having the above structure rotates with respect to the rotation axis, the lower rotating blade can rotate from a vertically standing state to a state of falling near the horizontal. At this time, the upper blade member coupled by the rotatable hinge is attracted by the other upper blade members having the same movement by the support member coupled via the third universal hinge, and thus rotates greatly and is bent. As a result, the plurality of upper and lower blade members are folded into a shape as if they were wound around the rotation axis, and can avoid strong winds. This series of operations occurs in conjunction with the rotation operation of the rotating hub, and the overall mechanism can be made extremely simple compared to operating each member individually. In addition, the movement of the support member enables the plurality of blade members to move synchronously, which is effective in making the operation of the present invention smooth. In the folded state (lying-down state), a part of the lower rotating blade overlaps with the upper rotating blade, so the substantial area receiving the wind can be reduced. Furthermore, the blade members folded horizontally do not leave the rotating axis standing upright for a long time, preventing the generation of wind noise and vibration, and not leaving practical problems.

Advantages of the Invention

[0008] As is clear from the above description, the folding windmill of the present invention can quickly fold the rotating blade portion of the vertically standing windmill to a low position with only a simple operation of rotating the rotating hub with respect to the rotation axis, so it can avoid sudden strong winds and effectively prevent damage accidents. Also, this operation is performed only by the rotation of each hinge portion, and since there is no exposure of a linear sliding portion, lubrication is easy. Therefore, the operating resistance is small and it can be moved with a light force. Therefore, the power used for the operation can also be small, which is extremely economical. Furthermore, it is not necessary to provide more strength than necessary during the design of the windmill, and a windmill that can operate lightly can be manufactured at low cost, so the substantial effect on wind power utilization technology is extremely remarkable.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying out the Invention

[0010] It is coupled to the other upper wing members 11 at each of the other vertices of the support member 14 Embodiments for realizing the present invention in a simplified manner without impairing the functions of the folding windmill are shown.

Examples

[0011] Figure 1 is a side view showing the standing state of one embodiment of the present invention. Figure 2 is a top view showing the folded state of one embodiment of the present invention. Figure 3 is a partial side view showing the rotating support arm portion in the folded state of one embodiment of the present invention. Figure 4 is a partial side view showing the support member in the folded state of one embodiment of the present invention. Figure 5 is a partial top view showing a view in the direction of arrow AA of the fixed support arm in the standing state of one embodiment of the present invention. Figure 6 is a partial top view showing a view in the direction of arrow BB of the rotating arm in the standing state of one embodiment of the present invention. Figure 7 is a partial top view showing a view in the direction of arrow CC of the support member in the standing state of one embodiment of the present invention.

[0012] In FIGS. 1 and 2, a plurality of fixed support arm members 3 are fixed to a hub 2 fixed to a rotating shaft 1. Further, a rotating hub 4 is rotatably attached to the rotating shaft 1 slightly above the hub 2. And a rotating support arm member 6 that can rotate in the vertical direction is provided on the rotating hub 4 via a circumferential rotating shaft 5. Lower wing members 9 are attached to the tip ends of the fixed support arm member 3 and the rotating support arm member 6 via universal movable hinges 7 and 8 respectively. The cross-section of the lower wing member 9 preferably has a shape similar to the cross-section of an aircraft wing, where the front end in the rotation direction shown by arrow A is rounded, the rear end is pointed, and the whole forms an arc along the rotation circumference. In the upright state, it extends long and substantially parallel to the rotating shaft 1 with the same cross-section. An upper wing member 11 is provided at the upper end of the lower wing member 9 via a hinge 10. The cross-sectional shape of the upper wing member 11 is also the same as that of the lower wing member 9. In the upright state, it extends long and substantially parallel to the rotating shaft 1 with the same cross-section as the lower wing member 9. The hinge 10 prevents the upper wing member 11 from bending outward beyond the upright state by a hinge stopper 12. Furthermore, a polygonal (triangle in the figure) support member 14 is coupled to a portion near the upper end of the upper wing member 11 via a third universal movable hinge 13, and other upper wing members 11 are coupled to other vertices of the support member 14 in the same manner. Also, a stopper 14 is provided on the fixed support arm member 3 to prevent the rotating support arm member 6 from rotating in the reverse direction of arrow D indicating the rotation direction with respect to the fixed support arm member 3. (Operation)

[0013] The operation of the folding windmill of the present invention having the above-described structure will be described. In the standing state, as shown in FIGS. 5 and 6, the fixed support arm member 3 and the pivot support arm member 6 are in a positional relationship where they overlap vertically, and this positional relationship is maintained by the stopper 14 and a spring or holding mechanism (not shown). Also, the hinge stopper 12 prevents the upper wing member 11 from bending outward beyond the upright state, and at a portion near the upper end of each upper wing member 11, another upper wing member 11 is coupled to the other apex of the support member 14 via the third freely movable hinge 13 in a similar shape, so that the upper wing member 11 can prevent bending due to the force of the wind. When the rotation hub 4 of the windmill having the above-described structure rotates in the direction of arrow D with respect to the rotation shaft 1, the lower rotating blades provided at the tip of the fixed support arm member 3 can be folded from the vertically standing state to a state close to horizontal. At this time, the upper wing member 9 coupled by the pivot hinge is rotated greatly and bent by the fact that the other upper wing member 11 makes a similar movement by the support member 14 coupled via the third freely movable hinge 13, so that the tip is pulled. The support member 14 has a relatively thin cross-sectional shape and is parallel to the wind, so the wind pressure resistance is small, and since the wind resistance is small, it is less likely to reduce the performance of the windmill itself.

[0014] When the rotation hub 4 rotates in the direction opposite to arrow A, the lower wing member 9 attached to the tips of the fixed support arm member 3 and the pivot support arm member 6 by the freely movable hinges 7 and 8 rises, and in conjunction with this movement, the upper wing member 11 attached to the upper end of the lower wing member 9 via the hinge 10 rises to a vertical state. Incidentally, this movement may be performed by an external power, but the rotational force due to the wind applied to the upper wing member 11 and the lower wing member 9 can also be used as it is. If the strength of the spring (not shown) is set appropriately, when the wind blows with a strength above a certain level, the lodging movement automatically starts, and excessive force due to strong wind can be avoided. When the wind weakens, the standing operation is automatically restarted. Although optimizing the setting of the spring strength requires a certain amount of technology, it is easy if an external force is used in combination, and the magnitude of the external force can be substantially reduced. Also, as is clear from the top view of FIG. 2, the overall rotation diameter of the lower wing member 9 and the lower wing member 9 when lying down is clearly larger than the diameter when standing up. Therefore, the standing and lying down operations are not directly affected by frequent wind speed changes, but are operated by the centrifugal force generated in the lower wing member 9 and the upper wing member 11 during the rotation of the windmill. Therefore, it has an operation including a certain degree of hysteresis, which is extremely preferable in practical use. Also, as shown in FIGS. 3, 4, 5, 6, and 7, all the movable parts of the present invention are rotational movements and do not involve sliding movements. Therefore, it is easy to seal the parts that require lubrication, which is an important feature for equipment such as windmills that are used outdoors for a long time. Also, when operating from the outside, the frictional force is small and the operating stability is high, so it has the basic advantage of having few failures.

Industrial Applicability

[0015] As is clear from the above description, the foldable windmill of the present invention can perform folding and standing operations with control by a small external force, and can appropriately avoid excessive wind resistance caused by strong winds, and can also avoid damage even due to drastic changes in the weather. The technical and industrial effects related to the use of natural energy are extremely remarkable.

Explanation of Signs

[0016] 1 Rotating shaft 2 Hub 3 Fixed support arm member 4 Rotating hub 5 Rotating shaft 6 Rotating support arm member 7·8 Universal movable hinge 9 Lower wing member A Arrow B Arrow C Arrow D Arrow 10 Hinge 11 Upper wing member 12 Hinge stopper 13 Third universal movable hinge 14 Support member

Claims

【Claim 1】 A plurality of fixed support arm members are fixed to a hub fixed to a rotating shaft. Also, a rotating hub is rotatably attached to the rotating shaft slightly above the hub. And a rotating support arm member that can rotate in the vertical direction is provided on the rotating hub via a circumferential rotation axis. Lower wing members are attached to the tip ends of the fixed support arm member and the rotating support arm member via universal movable hinges. The cross-section of the lower wing member preferably has a shape similar to the cross-section of an aircraft wing, and in the upright state, it extends long and substantially parallel to the rotating shaft in the same cross-section. An upper wing member is provided at the upper end of the lower wing member via a hinge. The cross-sectional shape of the upper wing member is also the same as that of the lower wing member, and in the upright state, it extends long and substantially parallel to the rotating shaft like the lower wing member. The hinge prevents the upper wing member from bending outward beyond the upright state by a hinge stopper. Furthermore, a polygonal support member is coupled via a third universal movable hinge to a portion near the upper end of the upper wing member, and other upper wing members are coupled in the same manner to other vertices of the support member, characterized by a foldable windmill configured as such.

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