Emergency stop structure for vertical axis wind turbines

Abstract

This invention provides an emergency stop structure for vertical-axis wind turbines that does not require a large backup power supply and has a strong force to stop the wind turbine. [Solution] When the vertical rotation shaft 2 reaches a preset limit rotation speed, the stopper 19 of the weight W is released, and the weight of the weight W drives the brake unit 14 to clamp the rotor 10 with a predetermined pressure, thereby allowing the wind turbine to be stopped in an emergency. Since the weight of the weight W drives the brake unit 14, a large backup power supply is not required. Also, because the brake unit 14 directly clamps the rotor 10, which is integrated with the vertical rotation shaft 2, the force that stops the wind turbine is strong. Furthermore, a restoration mechanism is provided, so it can be restored and used again.

Description

Technical Field

[0006] , , , ,

[0007] ,

[0001] The present invention relates to an emergency stop structure for a vertical-axis windmill.

Background Art

[0002] As a type of windmill for wind power generation, there is a lift-type vertical-axis windmill. It has a structure in which a plurality of lift blades are attached via a support frame extending radially around a vertical rotation axis. The rotational-direction component of the lift acting on the lift blade is used as a rotational force, and it has the advantage of good energy conversion efficiency.

[0003] However, once this type of windmill starts rotating, as long as it is exposed to wind, it continues to generate a rotational torque, and the rotation accelerates, which may lead to failure or destruction of the windmill. Therefore, when the rotational speed rises more than necessary, it is necessary to stop the windmill emergently.

[0004] Conventionally, as an emergency stop structure, a horizontal wing was attached to the vertical rotation axis, and the angle of the horizontal wing was changed by an electric motor to generate air resistance and stop the windmill (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in such related technologies, in order to stop the windmill, since the angle of the horizontal wing is changed by an electric motor, a large backup power source is required. Also, since it is a method of changing the angle of the horizontal wing rather than the lift blade itself, the force for stopping the windmill is weak.

[0007] This invention was made in view of such conventional technologies, and aims to provide an emergency stop structure for vertical-axis wind turbines that does not require a large backup power supply and has a strong force to stop the wind turbine. [Means for solving the problem]

[0008] According to a first technical aspect of the present invention, an emergency stop structure for a vertical-axis wind turbine, wherein the upper and lower ends of the vertical rotation axis are rotatably supported with respect to the upper and lower parts of a frame, and a plurality of blades that rotate integrally with the vertical rotation axis are attached around the vertical rotation axis via a support frame, is characterized by comprising: a horizontal disc-shaped rotor provided between the support frame of the vertical rotation axis and the upper or lower part of the frame and rotating integrally with the vertical rotation axis; a pair of upper and lower brake parts provided on the upper or lower part of the frame on the side on which the rotor is provided and capable of clamping the rotor with a predetermined pressure; and a drive unit that drives the brake parts by the weight of a weight to clamp the rotor when the vertical rotation axis reaches a preset limit rotation speed.

[0009] According to a second technical aspect of the present invention, the invention is characterized by being provided with a restoration mechanism that returns the weight to its original state after an emergency stop. [Effects of the Invention]

[0010] According to the first technical aspect of the present invention, when the vertical rotation shaft reaches a preset limit rotational speed, the weight stopper is released, and the weight of the weight drives the brake unit, which clamps the rotor with a predetermined pressure, thereby allowing the wind turbine to be stopped in an emergency. Since the weight of the weight drives the brake unit, a large backup power supply is not required. Furthermore, because the brake unit directly clamps the rotor, which is integrated with the vertical rotation shaft, the force that stops the wind turbine is strong.

[0011] According to a second technical aspect of the present invention, a restoration mechanism is provided to return the weight to its original state after an emergency stop, so that it can be restored and reused. [Brief explanation of the drawing]

[0012] [Figure 1] Perspective view of a vertical-axis wind turbine. [Figure 2] A perspective view showing the internal structure of a vertical-axis wind turbine. [Figure 3] Cross-sectional view of a vertical-axis wind turbine. [Figure 4] A perspective view showing the emergency stop mechanism. [Modes for carrying out the invention]

[0013] Figures 1 to 4 show preferred embodiments of the present invention.

[0014] In this embodiment, the vertical-axis wind turbine 1 has a vertical rotation axis 2 at its center, and its upper end 3 and lower end 4 are rotatably supported by the upper part 6 and lower part 7 of the frame 5 via bearings.

[0015] Support frames 8 are fixed above and below the vertical rotation axis 2, rotating integrally with the vertical rotation axis 2. Four lift blades 9 are mounted at equally angular intervals between the support frames 8. The lift blades 9 are fixed at an optimal pitch angle to maximize wind turbine efficiency. When the lift blades 9 receive wind F, a rotational component of lift is generated, and this rotational component of lift causes the lift blades 9 to rotate in the R direction around the vertical rotation axis 2. Note that the blades 9 may also be drag blades, as long as they receive wind and impart rotational force (torque) to the vertical rotation axis 2 and the support frames 8.

[0016] A horizontal disc-shaped rotor 10 that rotates integrally with the vertical rotation axis 2 is provided between the support frame 8 on the vertical rotation axis 2 and the lower part 7 of the frame 5. A base portion 11 is formed on the lower part 7 of the frame 5, and the fixing portion 13 of the emergency stop structure 12 is installed on this base portion 11.

[0017] The emergency stop structure 12 is provided with a pair of brake parts 14 on the fixed part 13 that sandwich the rotor 10 from above and below. The first shaft part S1 of the fixed part 13 passes through the brake parts 14 from above and below, and the brake parts 14 have screw parts N1 and N2 that are screwed in inversely. Therefore, depending on the rotation direction of the first shaft part S1, the upper and lower brake parts 14 move closer to or further away from each other in the vertical direction. A large-diameter first gear G1 is fixed to the lower part of the first shaft part S1.

[0018] A second shaft portion S2 is provided in close proximity to the first shaft portion S1. The second shaft portion S2 is provided with a small-diameter second gear G2 and a large-diameter third gear G3 that engage with the first gear G1, and a drum 16 on which a metal wire 15 is wound is provided below the third gear G3. The wire 15 suspends and supports a weight W at its lower end via a reel 17. A detection switch 18 is provided above the weight W.

[0019] A stopper 19 is provided on the upper surface of the third gear G3, with its tip protruding outward from the third gear G3. The tip of the stopper 19 contacts the rotating roller 21 of the solenoid 20, preventing the rotation of the third gear G3. The solenoid 20 is a rotary actuator that can rotate the rotating roller 21 45 degrees horizontally to release the contact between the rotating roller 21 and the stopper 19. Once released, the stopper 19 and the third gear G3 can rotate freely.

[0020] Near the second shaft portion S2, a third shaft portion S3 is provided. On the third shaft portion S3, a small-diameter fourth gear G4 that engages with the third gear G3 is provided. The fourth gear G4 is connected to a motor 23 via a clutch cam 22 that rotates only in one direction, and is rotated by this motor 23. The third shaft portion S3, the fourth gear G4, the clutch cam 22, and the motor 23 form a restoring mechanism. The clutch cam 22 is a one-way clutch using a cam mechanism. In the release direction in which the third gear G3 rotates as the weight W drops by its own weight, the fourth gear G4 idles, and in the opposite winding direction, the torque of the motor 23 can be transmitted to the fourth gear G4. That is, the fourth gear G4 idles following the third gear G3 in the release direction, while in the winding direction, the fourth gear G4 firmly engages with the third gear G3, and the fourth gear G4 rotates the third gear G3 in the winding direction by the rotational force of the motor 23.

[0021] Next, the operation will be described.

[0022] Normally, the upper and lower brake portions 14 are separated and a gap is formed, and the vertical rotating shaft 2 and the rotor 10 rotate freely. When it is detected by a rotation measuring device (not shown) that the rotation of the vertical rotating shaft 2 has reached the limit rotation speed, the solenoid 20 rotates, and its rotating roller 21 is released from the contact state with the stopper 19. Since the solenoid 20 consumes extremely small power compared to a motor that generates torque, a large-capacity backup power source is not required, and it can operate reliably even when the supplied power is unstable.

[0023] As a result, the third gear G3 is released, the weight W descends, the drum 16 rotates via the wire 15, and the second shaft section S2 and the second gear G2 rotate. When the second gear G2 rotates, the engaged first gear G1 rotates, the first shaft section S1 rotates, and the upper and lower brake sections 14 approach each other via the screw sections N1 and N2, clamping the rotor 10 with a predetermined pressure. As a result, the rotation of the rotor 10 is brought to an emergency stop. Therefore, the emergency stop structure 12 is a disc brake mechanism that operates solely by utilizing the weight (mechanical energy) of the weight W, and can quickly stop the rotation of the rotor 10 and the vertical rotation shaft 2 in an emergency. In addition, it does not require a large-capacity power supply during an emergency stop, and the solenoid 20 can be controlled to reliably stop the rotation of the support frame 8 and the lifting blade 9 as well.

[0024] To return the weight W to its original position after an emergency stop, the motor 23 rotates the fourth gear G4, which in turn rotates the third gear G3 to wind the wire 15 onto the drum 16. As the third gear G3 rotates, the upper and lower brake sections 14 also move in the opposite direction, allowing the vertical rotation axis 2 to rotate freely.

[0025] When the weight W contacts the detection switch 18, the motor 23 stops rotating, the solenoid 20 rotates the rotating roller 21, and it comes into contact with the stopper 19 of the third gear G3. As a result, the rotation of the third gear G3 and other gears stops, and emergency stop becomes possible again to restore to the original state. [Explanation of Symbols]

[0026] 1 vertical axis windmill 2 Vertical rotation axis 5. Stand 8. Support frame 9. Lifting blades 10 rotors 12 Emergency stop structure 14 Brake section S1, S2, S3 First shaft section to third shaft section G1, G2, G3, G4 1st gear to 4th gear R rotation direction F wind W weight

Claims

1. An emergency stop structure for a vertical-axis wind turbine, wherein the upper and lower ends of the vertical rotation axis are rotatably supported relative to the upper and lower parts of a mounting base, and a plurality of blades that rotate integrally with the vertical rotation axis are attached around the vertical rotation axis via a support frame, A horizontal disc-shaped rotor is provided between the support frame and the upper or lower part of the mounting base on the vertical rotation axis, and rotates integrally with the vertical rotation axis. A pair of upper and lower brake units are provided on the upper or lower part of the frame on the side where the rotor is installed, and are capable of clamping the rotor with a predetermined pressure. An emergency stop structure for a vertical-axis wind turbine, characterized by having a drive unit that uses the weight of a weight to drive a brake unit and clamp the rotor when the vertical rotation axis reaches a preset limit rotation speed.

2. The emergency stop structure for a vertical-axis wind turbine according to claim 1, characterized in that it is provided with a restoration mechanism that returns the weight to its original state after an emergency stop.

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