Vertical axis wind turbine with speed limit controlled by magnetic force

Abstract

The invention discloses a vertical axis wind driven generator with speed limit controlled by magnetic force, which comprises a generator, a fan main shaft, a connecting arm and blades, and the connecting arm comprises a connecting arm main piece, a wing tail plate, a pin shaft, a mass block, a large elastic piece, a magnet and a small elastic piece. During working, centrifugal force generated by rotation of the mass block and magnetic force of the magnets are used for controlling the wing tail plates of the connecting arms to be opened, and the rotating speed of the vertical-axis wind turbine is limited; meanwhile, the wing tail plate is controlled to automatically recover and close by utilizing the elasticity of the large elastic piece, the gravity of the wing tail plate and the magnetic force of the magnet. The magnetic force control speed limiting structure does not need electric power, the rotating speed of the vertical axis wind turbine is automatically limited, control is accurate, the wing tail plate can be automatically opened only when the rotating speed exceeds a set threshold value, and the whole mechanical structure is simple, stable and reliable.

Description

Technical Field

[0001] The invention belongs to the technical field of wind turbines, and in particular relates to a vertical axis wind turbine with magnetically controlled speed limit. Background Art

[0002] Wind energy is a sustainable green energy source. Wind turbines can convert wind energy into electrical energy. The power generation process is green, pollution-free and environmentally friendly. With global warming, the demand for green energy is increasing, and wind turbines are being used more and more. Wind turbines are mainly divided into two types: horizontal axis wind turbines and vertical axis wind turbines. Currently, all large commercial wind turbines are horizontal axis wind turbines, while vertical axis wind turbines are more advantageous than small wind turbines because of their low noise and the lack of a wind direction reversing mechanism.

[0003] However, when the power controller of the vertical axis wind turbine fails, the speed of the vertical axis wind turbine will be out of control and will increase with the increase of wind speed. Excessive speed will inevitably cause mechanical damage to the vertical axis wind turbine. In order to limit the speed of the vertical axis wind turbine, there are two solutions on the market: one is to add an independent speed limit circuit to reduce speed (such as the Chinese patent application with publication number CN108547734A). This solution can fully utilize the centrifugal force generated by the rotation of the wind turbine to control the speed of the main shaft during operation. The entire control process is self-regulated, and no additional control mechanism is needed to keep the generator shaft within a safe speed range for power generation. The other is to use elastic parts to control the speed limiting mechanism to slow down (such as the Chinese patent application with publication number CN105201743A). This solution uses elastic parts to keep the resistance plate in a retracted state. When the blade speed exceeds a critical value, the slider moves under the action of centrifugal force, and the resistance plate unfolds, which can reduce the blade speed; when the blade speed drops and reaches another critical value, under the action of the elastic part, the slider slides and resets, so that the resistance plate changes from an expanded state to a retracted state. This structure can automatically limit the blade speed without the need for additional power supply or manual control.

[0004] However, both of the above solutions have problems and defects. Adding an independent speed limit circuit will inevitably lead to a situation where the battery is out of power, and the circuit reliability and durability are not high, which will increase the cost. Using elastic parts to control the speed limit mechanism, because the elastic force of the elastic part follows Hooke's law, the deformation is linearly related to the elastic force, and the deformation is a continuous process, there will be inaccurate control. Before the set threshold speed is reached, the deformation of the elastic part will also control the speed limit mechanism. When the speed exceeds the set threshold, the elastic force of the elastic part increases as the deformation increases, and the speed limit mechanism will not be fully opened. Summary of the invention

[0005] In view of the above, the present invention provides a vertical axis wind turbine with magnetically controlled speed limit, which is a purely mechanical structure with higher reliability and durability and more precise magnetic control.

[0006] A vertical axis wind turbine with magnetically controlled speed limit comprises a generator, a fan main shaft, a connecting arm and blades, wherein the fan main shaft is fixed to the rotor of the generator, the connecting arm is mounted on the fan main shaft, and the blades are mounted on the connecting arm; the connecting arm comprises:

[0007] The connecting arm main part has one end fixed on the fan main shaft and the other end vertically connected to the blade;

[0008] A pin shaft is installed on one side of the connecting arm main part;

[0009] The wing tail plate is mounted on the pin shaft and is rotatably connected to the connecting arm main part through the pin shaft;

[0010] A magnet is fixedly mounted on the wing tail plate and is arranged on a closed surface between the wing tail plate and the connecting arm main part;

[0011] A mass block is arranged inside the connecting arm main part and close to the magnet;

[0012] A large elastic member, one end of which is fixed inside the connecting arm main member and the other end is connected to the mass block;

[0013] The small elastic part is fixedly mounted on the connecting arm main part and is arranged on the closing surface between the connecting arm main part and the wing tail plate.

[0014] Furthermore, the cross-sectional shape of the connecting arm is an airfoil, which can minimize the wind resistance of the connecting arm when it rotates in the air.

[0015] Furthermore, the connecting arm main part, the wing tail plate and the large elastic part are all made of non-magnetic materials.

[0016] Furthermore, the connecting arm main part is a main structural part for supporting the blades. When it is installed and fixed horizontally, the tail plate can rotate along the pin shaft by its own gravity until it is closed with the connecting arm main part.

[0017] Furthermore, a track for the mass block to slide is provided inside the connecting arm main part.

[0018] Furthermore, the mass block is made of magnetic material and generates magnetic attraction with the magnet. During the rotation of the connecting arm, if the rotation speed is below the set threshold and the centrifugal force of the mass block is less than the critical value of the magnetic attraction, the mass block and the magnet are tightly attracted together, and the wing tail plate and the connecting arm main part are closed. In this state, the cross-section of the connecting arm is an airfoil and the wind resistance is minimized. If the rotation speed exceeds the set threshold (in the case of a failure of the fan controller), the centrifugal force of the mass block is greater than the critical value of the magnetic attraction, and the mass block slides outward along the internal track of the connecting arm main part under the centrifugal force. As the distance between the mass block and the magnet increases, the magnetic attraction rapidly decreases to zero, and the mass block separates from the magnet.

[0019] Furthermore, when the mass block slides outward, the large elastic part is deformed, thereby storing energy in the large elastic part. The wing tail plate will still be closed with the connecting arm main part under its own gravity and air pressure. However, at this time, since the magnetic attraction disappears, the small elastic part will release the elastic force to open the wing tail plate and the connecting arm main part by a certain distance to form a gap. The wind will quickly enter the gap. Under the wind pressure, the wing tail plate is fully opened and perpendicular to the connecting arm main part. At this time, the wind resistance of the connecting arm is extremely large, which will quickly reduce the rotation speed of the vertical-axis wind turbine, thereby protecting the vertical-axis wind turbine from damage due to excessively high rotation speed.

[0020] Furthermore, when the wind speed in the environment decreases to 0, the vertical axis wind turbine will slowly stop rotating. At this time, the centrifugal force of the mass block disappears, and the mass block is restored to its original position under the elastic force of the large elastic part. The tail plate rotates under its own gravity and returns to a closed state, so that the magnets on the tail plate are close to the mass block and attract each other under the action of magnetic attraction, thereby completely closing the tail plate and the connecting arm main part and compressing the small elastic part to store energy. At this time, the connecting arm returns to the airfoil shape with minimal wind resistance.

[0021] Furthermore, the connecting arm, as a magnetically controlled speed limiting structure of the vertical axis wind turbine, can automatically reduce the rotation speed of the vertical axis wind turbine in the event of a wind turbine controller failure, thereby preventing the vertical axis wind turbine from being damaged.

[0022] The working principle of the vertical axis wind turbine of the present invention is as follows: when a problem occurs in the controller of the vertical axis wind turbine and the rotation speed exceeds the set threshold, the centrifugal force of the mass block is greater than the critical value of the magnetic attraction of the magnet to it, the mass block begins to slide, and as the distance between the mass block and the magnet increases, their magnetic attraction will rapidly decrease until it is zero, at which time the magnetic attraction that closes the wing tail plate and the connecting arm main part disappears, and the sliding of the mass block will drive the large elastic part to deform, thereby storing energy for the large elastic part. Because the self-gravity of the wing tail plate and the air pressure during high-speed rotation will still close the wing tail plate and the connecting arm main part, but the small elastic part installed on the connecting arm main part will release the elastic force to open the wing tail plate a certain distance, the wind will quickly enter the gap opened by the wing tail plate and the connecting arm main part, and fully open the wing tail plate to a state where the wind pressure received by the upper and lower surfaces of the pin shaft is equal, at which time the wind resistance of the connecting arm is extremely large, which will rapidly reduce the rotation speed of the vertical axis wind turbine, thereby protecting the vertical axis wind turbine from being damaged due to excessively high rotation speed. When the wind speed in the environment stops, the vertical axis wind turbine will also slowly stop rotating. At this time, the centrifugal force of the mass block disappears, and the elastic force stored in the large elastic part restores it to its original position; the tail plate rotates under its own gravity and returns to a closed state. When the magnet on the tail plate approaches the mass block, the tail plate and the main part of the connecting arm are closed under the action of the mutual magnetic attraction, and the small elastic part is compressed to store energy. At this time, the connecting arm returns to the airfoil state with the minimum wind resistance.

[0023] Based on the above technical solution, the present invention has the following beneficial technical effects:

[0024] 1. The magnetic controlled speed limiting structure of the present invention can limit the speed of the vertical axis wind turbine to not be too high and cause damage to the wind turbine, thereby protecting assets.

[0025] 2. The magnetic force controlled speed limiting structure of the present invention is a purely mechanical structure without circuits, and has a simple structure and is stable and reliable.

[0026] 3. The magnetically controlled speed limiting structure of the present invention is magnetically controlled. Only when the speed of the vertical axis wind turbine exceeds the set threshold, the centrifugal force of the mass block is greater than the magnetic attraction of the magnet, the speed limiting tail plate will be controlled to open. Otherwise, it will be firmly attracted, and the control will be more precise. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The figure is a schematic diagram of the overall structure of the vertical axis wind turbine with magnetically controlled speed limit according to the present invention.

[0028] Figure 2 Schematic diagram of the perspective structure of the connecting arm.

[0029] Figure 3 Schematic diagram of the cross-sectional structure of the connecting arm.

[0030] Figure 4 This is a schematic diagram of the cross-sectional structure of the connecting arm when the wing tail panel is just opened.

[0031] Figure 5 It is a schematic diagram of the cross-sectional structure of the connecting arm when the wing tail panel is fully opened.

[0032] In the figure: 1 - generator, 2 - fan main shaft, 3 - connecting arm, 4 - blade, 31 - connecting arm main part, 32 - wing tail plate, 33 - pin shaft, 34 - mass block, 35 - large elastic body, 36 - magnet, 37 - small elastic body. DETAILED DESCRIPTION

[0033] In order to describe the present invention more specifically, the technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0034] like Figure 1 As shown, this embodiment provides a vertical axis wind turbine with magnetically controlled speed limit, which includes: a generator 1, a fan main shaft 2, two upper and lower sets of connecting arms 3 and three blades 4. The fan main shaft 2 is installed on the rotor of the generator 1, the connecting arm 3 is installed on the fan main shaft 2, and the blades 4 are installed on the upper and lower sets of connecting arms 3.

[0035] like Figure 2 and Figure 3 As shown, the connecting arm 3 is in a normal closed state, and the cross-sectional shape is an airfoil, which minimizes the wind resistance of the connecting arm 3 when rotating in the air; the connecting arm 3 includes:

[0036] A connecting arm main part 31, one end of which is mounted on the fan main shaft 2, and the other end is connected to the blade 4;

[0037] The wing tail plate 32 is rotatably mounted on the connecting arm main part 31;

[0038] The pin 33 is used to rotatably mount the wing tail plate 32 on the connecting arm main part 31;

[0039] The mass block 34 is slidably disposed in the connecting arm main part 31;

[0040] A large elastic member 35, one end of which is fixedly mounted in the connecting arm main member 31, and the other end of which is connected to the mass block 34, so as to restore the mass block 34 to its original position;

[0041] A magnet 36 is fixedly mounted on the wing tail plate 32;

[0042] The small elastic member 37 is fixedly mounted on the connecting arm main member 31 .

[0043] The connecting arm main component 31 is the main structural component supporting the blade 4. It is made of non-magnetic material and cannot generate magnetic attraction with the magnet 36. It is installed horizontally, one end is fixedly connected to the fan main shaft 2, and the other end is fixedly connected to the blade 4. It is rotatably connected to the wing tail plate 32 in the horizontal length direction, and there is a chamber or track inside it for the mass block 34 to slide.

[0044] The wing tail plate 32 is a speed-limiting structure that will generate resistance when opened. It is made of non-magnetic material and cannot generate magnetic attraction with the magnet 36. It is rotatably connected to the connecting arm main component 31 in the length direction. When it is stationary, it can rotate to a closed state with the connecting arm main component 31 by its own gravity.

[0045] The pin shaft 33 is the rotating shaft for rotationally connecting the wing tail plate 32 and the connecting arm main component 31. The mass block 34 is the main component of magnetic force control. It is made of magnetic material and is located near the magnet 36 in space. It can generate magnetic attraction with the magnet 36. It is slidably set on the chamber or track of the connecting arm main component 31 and can only slide along the length direction of the connecting arm main component 31.

[0046] One end of the large elastic member 35 is fixedly installed in the connecting arm main member 31, and the other end is connected to the mass block 34. When the mass block 34 slides away from the original position, the large elastic member 35 will be deformed, and the elastic force of the large elastic member 35 can restore the mass block 34 to its original position. The magnet 36 is fixedly installed on the wing tail plate, and is located near the mass block 34 in space, and will generate magnetic attraction with the mass block 34.

[0047] The small elastic member 37 is fixedly mounted on the connecting arm main member 31. When the connecting arm 3 is in a normal closed state, the small elastic member 37 is in a compressed deformation state. When the mass block 34 slides and does not generate magnetic attraction with the magnet 36, the wing tail plate 32 can be opened a certain distance.

[0048] like Figure 3 As shown, when the rotation speed of the vertical axis wind turbine is below the set threshold, the centrifugal force of the mass block 34 is less than the critical value of the magnetic attraction of the magnet 36, and the mass block 34 and the magnet 36 are firmly attracted together, that is, the tail plate 32 is closed on the connecting arm main part 31. In this state, the cross-sectional shape of the connecting arm 3 is an airfoil, and the wind resistance is minimized.

[0049] like Figure 4 and Figure 5As shown, when a problem occurs in the controller of the vertical axis wind turbine and the rotation speed exceeds the set threshold, the centrifugal force of the mass block 34 is greater than the critical value of the magnetic attraction of the magnet 36, and the mass block 34 begins to slide. As the distance between the mass block 34 and the magnet 36 increases, their magnetic attraction will rapidly decrease until it reaches zero, at which point the magnetic attraction that closes the wing tail plate 32 and the connecting arm main component 31 disappears. The sliding of the mass block 34 will cause the large elastic component 35 to deform, thereby storing energy in the large elastic component 35; the self-gravity of the wing tail plate 32 and the air pressure during high-speed rotation will still close the wing tail plate 32 and the connecting arm main component 31, but the small elastic component 37 installed on the connecting arm main component 31 will release the elastic force to open the wing tail plate 32 by a certain distance, as shown in FIG. Figure 4 shown.

[0050] The wind will quickly enter the gap between the wing tail plate 32 and the connecting arm main part 31, and fully open the wing tail plate 32 until the wind pressure on the surface above and below the rotating shaft is equal. Figure 5 As shown. At this time, the wind resistance of the connecting arm 3 is extremely large, which will quickly reduce the rotation speed of the vertical axis wind turbine, thereby protecting the vertical axis wind turbine from damage due to excessive rotation speed. When the wind speed in the environment stops, the vertical axis wind turbine will also slowly stop rotating. At this time, the centrifugal force of the mass block 34 disappears, and it is restored to its original position under the elastic force stored in the large elastic member 35. The tail plate 32 rotates under its own gravity to restore to the closed state. When the magnet 36 on the tail plate 32 approaches the mass block 34, the tail plate 32 and the connecting arm main part 31 are closed under the action of the mutual magnetic attraction, and the small elastic member 37 is compressed to store energy. At this time, the connecting arm 3 is restored to the airfoil state with the minimum wind resistance.

[0051] The advantage of this embodiment is that the magnetically controlled speed limiting mechanism is a purely mechanical mechanism, without circuits, with a simple structure, stable and reliable, and at the same time utilizes the characteristics of magnetic attraction: the two attracted objects will only be separated when the external force is greater than the magnetic attraction, and the attraction will decrease rapidly as the separation distance increases, that is, only when the speed of the vertical axis wind turbine exceeds the set threshold, the centrifugal force of the mass block is greater than the magnetic attraction of the magnet, the speed limiting tail plate will be controlled to open, otherwise it will be firmly attracted, so that the speed limiting mechanism can be controlled more accurately.

[0052] The above description of the embodiments is to facilitate the understanding and application of the present invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to the above embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments. Improvements and modifications made by those skilled in the art to the present invention based on the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A vertical axis wind turbine with magnetically controlled speed limit, comprising a generator, a fan main shaft, a connecting arm and blades, wherein the fan main shaft is fixed to the rotor of the generator, the connecting arm is mounted on the fan main shaft, and the blades are mounted on the connecting arm, characterized in that: The connecting arm comprises: The connecting arm main part has one end fixed on the fan main shaft and the other end vertically connected to the blade; A pin shaft is installed on one side of the connecting arm main part; The wing tail plate is mounted on the pin shaft and is rotatably connected to the connecting arm main part through the pin shaft; A magnet is fixedly mounted on the wing tail plate and is arranged on a closed surface between the wing tail plate and the connecting arm main part; A mass block is arranged inside the connecting arm main part and close to the magnet; A large elastic member, one end of which is fixed inside the connecting arm main member and the other end is connected to the mass block; The small elastic part is fixedly mounted on the connecting arm main part and is arranged on the closing surface between the connecting arm main part and the wing tail plate.

2. The vertical axis wind turbine according to claim 1, characterized in that: The cross-sectional shape of the connecting arm is an airfoil, which can minimize the wind resistance when the connecting arm rotates in the air.

3. The vertical axis wind turbine according to claim 1, characterized in that: The connecting arm main part, the wing tail plate and the large elastic part are all made of non-magnetic materials.

4. The vertical axis wind turbine according to claim 1, characterized in that: The connecting arm main part is the main structural part for supporting the blades. When it is installed and fixed horizontally, the tail plate rotates along the pin shaft by its own gravity until it is closed with the connecting arm main part.

5. The vertical axis wind turbine according to claim 1, characterized in that: A track for the mass block to slide is arranged inside the connecting arm main part.

6. The vertical axis wind turbine according to claim 1, characterized in that: The mass block is made of magnetic material and generates magnetic attraction with the magnet. During the rotation of the connecting arm, if the rotation speed is below the set threshold and the centrifugal force of the mass block is less than the critical value of the magnetic attraction, the mass block and the magnet are tightly attracted together, and the wing tail plate and the connecting arm main part are closed. In this state, the cross-section of the connecting arm is an airfoil and the wind resistance is minimized. If the rotation speed exceeds the set threshold, the centrifugal force of the mass block is greater than the critical value of the magnetic attraction, and the mass block slides outward along the internal track of the connecting arm main part under the centrifugal force. As the distance between the mass block and the magnet increases, the magnetic attraction rapidly decreases to zero, and the mass block separates from the magnet.

7. The vertical axis wind turbine according to claim 6, characterized in that: When the mass block slides outward, the large elastic part is deformed, thereby storing energy in the large elastic part. The wing tail plate will still be closed with the connecting arm main part under its own gravity and air pressure. However, at this time, due to the disappearance of the magnetic attraction, the small elastic part will release the elastic force to open the wing tail plate and the connecting arm main part by a certain distance to form a gap. The wind will quickly enter the gap. Under the wind pressure, the wing tail plate is fully opened and perpendicular to the connecting arm main part. At this time, the wind resistance of the connecting arm is extremely large, which will quickly reduce the speed of the vertical-axis wind turbine, thereby protecting the vertical-axis wind turbine from damage due to excessive speed.

8. The vertical axis wind turbine according to claim 7, characterized in that: When the wind speed in the environment decreases to 0, the vertical axis wind turbine will slowly stop rotating. At this time, the centrifugal force of the mass block disappears, and the mass block is restored to its original position under the elastic force of the large elastic part. The tail plate rotates under its own gravity and returns to a closed state, so that the magnets on the tail plate are close to the mass block and attract each other under the action of magnetic attraction, thereby completely closing the tail plate and the connecting arm main part and compressing the small elastic part to store energy. At this time, the connecting arm returns to the airfoil shape with the minimum wind resistance.

9. The vertical axis wind turbine according to claim 1, characterized in that: The connecting arm serves as a magnetic control speed limiting structure of the vertical axis wind turbine, and can automatically reduce the rotation speed of the vertical axis wind turbine in the event of a wind turbine controller failure, thereby preventing the vertical axis wind turbine from being damaged.

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