JP7787569B2 - Drag type vertical axis wind turbine structure - Google Patents

Description

The present invention relates to a drag-type vertical axis wind turbine structure.

Vertical axis wind turbines are a well-known type of wind turbine used for generating electricity. Unlike horizontal axis wind turbines, such as the propeller type, vertical axis wind turbines have the advantage of rotating regardless of wind direction. There are two types of vertical axis wind turbines: drag type, in which the drag generated by the blades becomes rotational force, and lift type, in which the lift generated by the blades becomes rotational force.

Drag-type vertical axis wind turbines have a simple structure and are able to rotate and generate electricity even at low wind speeds. Therefore, drag-type vertical axis wind turbines are suitable for areas where wind speed and direction change frequently, such as urban areas and city centers in Japan.

This type of drag-type vertical axis wind turbine also has its own issues. Specifically, in the half of the vertical axis wind turbine that runs from the center of the windward side toward the direction of rotation, the drag generated by the wind on the blades directly becomes rotational force, but in the opposite half, the wind hitting the blades generates drag in the opposite direction to the rotational force. This creates a structural problem in that it is not possible to generate sufficient rotational force.

In the wind turbine of Patent Document 1, the blades are adjusted to an angle that generates drag in one half of the region along the direction of rotation, and conversely, the blades are adjusted to an angle that generates less drag in the opposite half, allowing rotational force to be generated by the difference in drag (see Patent Document 1, for example).

Patent No. 6443913

However, even with this type of related technology, it is unavoidable that the wind will hit the blades in the half area opposite the direction of rotation, which inevitably generates drag in the opposite direction to the rotation, limiting the amount of rotational force that can be obtained and preventing further improvements in power generation capacity.

The present invention was made with a focus on this related technology, and aims to provide a drag-type vertical axis wind turbine structure that virtually eliminates the drag generated in the direction opposite to the rotational direction, thereby increasing rotational force and further improving power generation capacity.

According to a first technical aspect of the present invention, a drag-type vertical axis wind turbine structure is provided in which rotating frames that rotate horizontally around a vertical rotation axis are fixed above and below the vertical rotation axis, and multiple drag blades are attached at equiangular intervals between the upper and lower rotating frames, rotating in a fixed direction. The drag blades are rotatably supported by a support shaft at one end relative to the rotating frame, and the rotating frame is provided with inner and outer stoppers at positions radially around the vertical rotation axis, sandwiching the support shaft. In a first half region of the rotating frame extending from the center of the windward side toward the direction of rotation, the drag blades abut against the upwind side of the inner stoppers, and the outer stoppers abut against the drag blades, limiting their rotation range. In a second half region opposite the above, the drag blades are prevented from reaching the upwind side of the inner stoppers and abutting against the inner stoppers.

According to a second technical aspect of the present invention, the drag blade is provided with a counterweight that extends from the support shaft toward the drag blade and equalizes the weight balance around the support shaft.

According to a first technical aspect of the present invention, the drag blade abuts the upwind side of the inner stopper in the first half region of the rotating frame, allowing it to rotate and generate electricity due to the wind resistance it receives there. Only the first half region receives the wind, while in the opposite second half region, the drag blade is in a free state, not abutting either the inner or outer stopper, and moves in a non-resisting state along the wind, allowing it to rotate reliably due to the resistance generated only in the first half region. In particular, the rotation range of the drag blade in the second half region is limited by the outer stopper, so the drag blade will not wrap around to the upwind side of the inner stopper and abut. As a result, the drag blade will not behave in the same way in the second half region as it is in the first half region.

According to a second technical aspect of the present invention, a counterweight is provided on the drag blade, which reduces the momentum of the drag blade as it rotates around the support shaft and mitigates the impact when the drag blade abuts against the inner stopper or outer stopper.

Overall view of the drag-type vertical axis wind turbine structure housed in a frame. Overall view of the drag-type vertical axis wind turbine structure. Plan view of drag type vertical axis wind turbine structure. Cross-section of a drag-type vertical axis wind turbine structure. 4 is a cross-sectional view taken along the line SA-SA indicated by the arrows in FIG. 3. FIG. Schematic plan view of a drag type vertical axis wind turbine structure showing the rotation state. FIG. 8 is a schematic plan view equivalent to FIG. 7, with the outer stopper omitted.

Figures 1 to 8 show preferred embodiments of the present invention.

The drag-type vertical axis wind turbine structure 1 of this embodiment is housed inside a rectangular frame 2. The frame 2 is designed to allow each drag-type vertical axis wind turbine device 1 to be stacked vertically, and has cylindrical sections 3 at its four corners for stacking purposes.

The drag-type vertical axis wind turbine structure 1 has a vertical rotation shaft 4 at its center, the upper and lower ends of which are rotatably supported in the center of the frame 2. A pulley 5 (see Figure 4) is provided at the top of the vertical rotation shaft 4 to extract rotational force and transmit it to a generator (not shown).

Rotating frames 6 are fixed above and below the vertical rotation shaft 4, rotating horizontally around the vertical rotation shaft 4. Eight drag blades 8 are provided vertically at equal angular intervals between the upper and lower rotating frames 6. When the drag blades 8 receive wind F, they continue to rotate in direction R. This drag-type vertical axis wind turbine structure 1 is not directional to wind F and can rotate in response to wind from any direction.

The reaction blade 8 is supported by a support shaft 9 at one end, which is rotatable relative to the rotating frame 6. Counterweights 10 are installed above and below the support shaft 9 on the reaction blade 8 side to even out the weight balance around the support shaft 9.

The upper and lower rotating frames 6 are each provided with an inner stopper 11 and an outer stopper 12, positioned radially around the vertical rotation axis 4 and sandwiching the support shaft 9. Furthermore, pins 13 are provided at the upper and lower ends of the support shaft 9 that pass through the rotating frames 6, facing in the same direction as the drag blade 8.

In the first half area A, which extends from the center of the upwind side of the rotating frame 6 toward the rotation direction R, the pin 13 (drag blade 8) abuts against the upwind side of the inner stopper 11 and receives wind F (see Figure 7). In the opposite second half area B, the outer stopper 12 and inner stopper 11 are aligned horizontally in the wind direction, so the pin 13 (drag blade 8) does not abut against either and is aligned in the direction of wind F with the support shaft 9 at the front. Therefore, no drag is generated in the second half area B.

The function of the outer stopper 12 will now be explained. The outer stopper 12 abuts against the drag blade 8, limiting the range of rotation of the drag blade 8 and preventing the drag blade 8 from reaching the upwind side of the inner stopper 11 and abutting against it in the second half region B.

Figure 8 does not show the outer stopper 12. Without the outer stopper 12, the drag blade 8 would rotate irregularly, and would come around to the upwind side of the inner stopper 11 in the second half region B and come into contact with it. This would cause the drag blade 8 to be subjected to wind F in the second half region B, generating drag in the opposite direction to the original rotation direction R, preventing normal rotation.

In addition, the drag blade 8 in this embodiment is provided with a counterweight 10, which adds an appropriate moment of inertia when the drag blade 8 rotates around the support shaft 9, stabilizing sudden changes in rotational speed and suppressing the contact speed when the pin 13 (drag blade 8) abuts the inner stopper 11 or outer stopper 12. Furthermore, the weight balance reduces the mechanical load on the support shaft 9, improving the durability of the pin 13 and other structures.

As explained above, in the drag-type vertical axis wind turbine structure 1 of this embodiment, the drag blades 8 receive the wind F only in the first half area A, which virtually eliminates the drag generated in the second half area B on the opposite side of the rotation direction, increasing the rotational force and further improving power generation capacity.

In this embodiment, an example is shown in which the drag blade 8 indirectly abuts against the inner stopper 11 and outer stopper 12 via the pin 13, but a structure in which it abuts directly may also be used.

REFERENCE SIGNS LIST 1 Drag type vertical axis wind turbine structure 2 Mounting base 4 Vertical rotating shaft 6 Rotating frame 8 Drag blade 9 Support shaft 10 Counterweight 11 Inner stopper 12 Outer stopper 13 Pin A First half area B Second half area

Claims (2)

A drag type vertical axis wind turbine structure in which rotating frames that rotate horizontally around the vertical rotation axis are fixed above and below the vertical rotation axis, and a plurality of drag blades are attached along the vertical direction at equiangular intervals between the upper and lower rotating frames, and rotate in a fixed direction,
The drag blade has a support shaft at one end rotatably supported on a rotating frame,
The rotating frame is provided with an inner stopper and an outer stopper at positions on either side of the support shaft in a radial direction from the vertical rotation axis, and the drag blade abuts against the windward side of the inner stopper in a first half region extending from the center of the windward side of the rotating frame toward the rotation direction,
A drag type vertical axis wind turbine structure characterized in that the outer stopper abuts against the drag blade to limit the rotation range of the drag blade, and prevents the drag blade from going around to the upwind side of the inner stopper and abutting against the inner stopper in the second half region opposite to the outer stopper. The drag-type vertical axis wind turbine structure according to claim 1, characterized in that the drag blade is provided with a counterweight that extends from the support shaft toward the drag blade and equalizes the weight balance around the support shaft.