CN110086376B - Small wind energy collector with frequency and displacement amplification function - Google Patents

Abstract

The invention relates to a small wind energy collector with frequency and displacement amplifying functions, comprising a fishbone beam, a base and a rotating excitation component, the fixed end of the fishbone beam is fixedly connected with the base, and the rotating excitation component is connected to the base through the support Fixed connection, non-contact magnetic coupling or contact coupling between the rotating excitation component and the free end of the fishbone beam. Piezoelectric sheets are symmetrically pasted on the upper and lower sides of the fishbone beam. The fishbone beam consists of the central axis of the fishbone beam, the fishbone beam The comb teeth and the tail beam are composed. The comb teeth of the fishbone beam are arranged on the central axis of the fishbone beam, and the tail beam is connected with the central axis of the fishbone beam. The longitudinal length of the comb teeth of the fishbone beam decreases linearly from the fixed end to the free end, and decreases. The product of the small ratio and the increase ratio of the deflection of the central axis of the fishbone beam is approximately a constant, and the end surfaces of all the teeth of the fishbone beam comb teeth are in the same plane; It starts vibrating under high wind speed, and will not deform too much and damage the piezoelectric sheet. It is suitable for working in a wide speed range.

Description

Small wind energy harvester with frequency and displacement amplification

[Technical field]

The invention relates to the technical field of energy collection, in particular to a small wind energy collector with frequency and displacement amplification.

[Background technique]

Energy harvesting devices can harvest energy from fluids. Most of the traditional wind power generation and hydropower generation devices use rotating turbine devices, which have low energy density and large volume, and are not suitable for miniaturization work. Flow-induced vibration energy harvesting based on piezoelectric materials is a small-scale fluid energy harvesting method with high energy density. Flow-induced vibration means that when the fluid flows around the bluff body, the bluff body vibrates due to periodic flow force, such as flutter, vortex-induced vibration, galloping vibration, and wake galloping vibration. However, flow-induced vibration has many limitations, such as: vortex-induced vibration has a large amplitude near the natural frequency of the vibration system, and cannot effectively collect energy in a wide range of velocity domains; flow-induced vibration cannot work effectively at low flow rates; even if The higher the flow rate, the lower the vibration frequency caused by the flow, which seriously affects the output power.

[Content of the Invention]

The purpose of the present invention is to solve the above deficiencies and provide a small wind energy harvester with frequency and displacement amplification, which can increase the output power, and can vibrate at low wind speeds without excessive deformation at high wind speeds. It is suitable for working in a wide speed range, and solves the problems of low energy density of the existing flow-induced vibration energy harvesting technology, small deformation at low wind speed, high starting wind speed, and narrow effective working wind speed range.

In order to achieve the above purpose, a small wind energy collector with frequency and displacement amplification is designed, comprising a fishbone beam 1, a base 2, and a rotary excitation assembly 3, and the fishbone beam 1 is arranged on the base 2 and the rotation excitation assembly 3. At the intermediate position, the fixed end of the fishbone beam 1 is fixedly connected to the base 2, the rotation excitation assembly 3 is rotatably connected to the support 4, and the other end of the support 4 is fixedly connected to the base 2 Above, the rotational excitation component 3 is non-contact magnetic coupling with the free end of the fishbone beam 1 , and piezoelectric sheets 5 are symmetrically pasted on the upper and lower sides of the fishbone beam 1 .

Further, the fishbone beam 1 is made up of the fishbone beam central axis 6, the fishbone beam comb teeth 7 and the tail beam 8, and the fishbone beam comb teeth 7 are symmetrical up and down, and are arranged on the fishbone beam central axis 6 at intervals. , the tail beam 8 is arranged at the free end of the fishbone beam 1, and is connected with the center axis 6 of the fishbone beam as a whole, and the longitudinal length of the fishbone beam comb teeth 7 decreases linearly from the fixed end to the free end, and the reduction The product of the small ratio and the increase ratio of the deflection of the central axis 6 of the fishbone beam is approximately constant, and the end surfaces of all the teeth of the fishbone beam comb teeth 7 are in the same plane.

Further, the rotation excitation assembly 3 includes a blade 9, a rotation shaft 10, a pair of bearings 11, and a rotation arm 12. The blade 9 and the rotation arm 12 are fixed on the rotation shaft 10, and the rotation shaft 10 passes through a pair of bearings. 11 is rotatably connected to the support 4, the end of the rotating arm 12 and the end of the tail beam 8 are respectively fixed with an excitation permanent magnet 13 and an excited permanent magnet 14, and the excitation permanent magnet 13 and the excited permanent magnet 14 are carried out between the Contactless magnetic coupling.

Further, T-shaped permanent magnet mounting plates are provided at the ends of the rotating arm 12 and the tail beam 8 .

Further, a frequency modulation mass block 17 is fixed at the end of the fishbone beam comb teeth 7, the system natural frequency of the fishbone beam comb teeth 7 and the frequency modulation mass block 17 and the system natural frequency of the tail beam 8 and the excited permanent magnet 14 The ratio is 2:1 or 3:1.

The present invention also provides a small wind energy harvester with frequency and displacement amplification, comprising a fishbone beam 1, a base 2, and a rotational excitation assembly 3, wherein the fishbone beam 1 is arranged on the base 2 and the rotational excitation assembly 3 At the intermediate position, the fixed end of the fishbone beam 1 is fixedly connected to the base 2, the rotation excitation assembly 3 is rotatably connected to the support 4, and the other end of the support 4 is fixedly connected to the base 2 Above, the rotational excitation assembly 3 is contact-coupled with the free end of the fishbone beam 1 , and piezoelectric sheets 5 are symmetrically pasted on the upper and lower sides of the fishbone beam 1 .

Further, the fishbone beam 1 is made up of the fishbone beam central axis 6, the fishbone beam comb teeth 7 and the tail beam 8, and the fishbone beam comb teeth 7 are symmetrical up and down, and are arranged on the fishbone beam central axis 6 at intervals. , the tail beam 8 is arranged at the free end of the fishbone beam 1, and is connected with the center axis 6 of the fishbone beam as a whole, and the longitudinal length of the fishbone beam comb teeth 7 decreases linearly from the fixed end to the free end, and the reduction The product of the small ratio and the increase ratio of the deflection of the central axis 6 of the fishbone beam is approximately constant, and the end surfaces of all the teeth of the fishbone beam comb teeth 7 are in the same plane.

Further, the rotation excitation assembly 3 includes a blade 9, a rotation shaft 10, a pair of bearings 11, and a rotation arm 12. The blade 9 and the rotation arm 12 are fixed on the rotation shaft 10, and the rotation shaft 10 passes through a pair of bearings. 11 is rotatably connected to the support 4, and the end of the rotating arm 12 and the end of the tail beam 8 are respectively provided with a hemispherical excitation head 15 and an excited head 16. Contact coupling.

Further, a frequency modulation mass block 17 is fixed at the end of the fishbone beam comb teeth 7, and the system natural frequency of the fishbone beam comb teeth 7 and the frequency modulation mass block 17 is equal to the system natural frequency of the tail beam 8 and the excited head 16. The ratio is 2:1 or 3:1.

Further, the fishbone beam 1 is made of elastic material and processed by 3D printing, and the rotating arm 12 is an array type rotating arm structure and is made of a material with low rigidity.

Compared with the prior art, the present invention has the following advantages:

(1) The present invention has a novel, simple structure and reasonable design, and utilizes the fishbone beam with a comb-tooth structure to amplify the bending deformation of the cantilever beam, thereby amplifying the deformation of the piezoelectric sheet pasted on the comb-tooth structure, and improving the output voltage and power;

(2) The present invention combines the advantages of rotation and vibration, and converts the rotational motion into the vibration of the fishbone beam through magnetic coupling or contact, so that the fishbone beam is easier to vibrate, and under low wind speed, the piezoelectric fishbone beam can work effectively, And under high wind speed, the fishbone beam will not cause excessive deformation and damage the piezoelectric sheet, and can work effectively in a wide speed range;

(3) The present invention adopts an array excitation mode, which can amplify the excitation frequency, generate power from low-frequency tail beam start-up and high-frequency comb-tooth structure, and can also increase the power generation frequency and increase the average output power by means of resonance;

(4) The present invention avoids the shortcomings of the existing flow-induced vibration energy harvesting technology, such as low energy density, small deformation at low wind speed, high starting wind speed, and narrow effective working wind speed range.

[Description of drawings]

1 is a schematic diagram of the three-dimensional structure of Embodiment 1 of the present invention;

FIG. 2 is a schematic diagram of the three-dimensional structure of Embodiment 2 of the present invention;

3 is a schematic structural diagram of a piezoelectric sheet and a fishbone beam in Embodiment 1 of the present invention;

4 is a schematic structural diagram of a piezoelectric sheet and a fishbone beam in Embodiment 2 of the present invention;

5 is a schematic diagram of the comb tooth structure of the fishbone beam in the present invention;

6 is a schematic structural diagram of a rotary excitation assembly in Embodiment 1 of the present invention;

7 is a schematic structural diagram of a rotary excitation assembly in Embodiment 2 of the present invention;

8 is a schematic diagram of contactless excitation in Embodiment 1 of the present invention;

9 is a schematic diagram of contact excitation in Embodiment 2 of the present invention;

10 is a schematic diagram of the work flow of the present invention;

In the figure: 1, fishbone beam 2, base 3, rotary excitation assembly 4, support 5, piezoelectric sheet 6, fishbone beam central axis 7, fishbone beam comb teeth 8, tail beam 9, blade 10, rotation Shaft 11, bearing 12, rotating arm 13, excitation permanent magnet 14, excited permanent magnet 15, hemispherical excitation head 16, excited head 17, frequency modulation mass.

[Detailed ways]

Below in conjunction with accompanying drawing, the present invention is described further below:

The present invention provides a small wind energy harvester with frequency and displacement amplification, comprising a fishbone beam 1, a base 2, and a rotational excitation assembly 3, and the fishbone beam 1 is arranged between the base 2 and the rotational excitation assembly 3 The fixed end of the fishbone beam 1 is fixedly connected to the base 2, and the rotary excitation assembly 3 is fixedly connected to the base 2 through the support 4, that is, the rotary excitation assembly 3 is rotatably connected to the support 4, and the other end of the support 4 Fixedly connected on the base 2, the rotating excitation assembly 3 is non-contact magnetic coupling or contact coupling with the free end of the fishbone beam 1, wherein, Figure 1 is a non-contact structure, Figure 2 is a contact structure, and the fishbone Piezoelectric sheets 5 are symmetrically pasted on both sides of the beam 1 .

As shown in the accompanying drawings 3 to 5, the fishbone beam 1 is composed of the fishbone beam central axis 6, the fishbone beam comb teeth 7 and the tail beam 8, and the fishbone beam comb teeth 7 are symmetrical up and down, and are arranged at intervals on the fishbone beam On the central axis 6, the tail beam 8 is arranged on the free end of the fishbone beam 1, and is connected with the central axis 6 of the fishbone beam as a whole, and the length of the fishbone beam comb teeth 7 linearly decreases from the fixed end to the free end, and decreases. The product of the ratio and the increase ratio of the deflection of the central axis 6 of the fishbone beam is approximately a constant, so that when the fishbone beam 1 is bent, the spacing of all adjacent teeth of the fishbone beam comb tooth 7 changes approximately the same degree, and all the teeth of the fishbone beam comb tooth 7 are approximately the same. The end surfaces are in the same plane.

As shown in FIG. 6 and FIG. 7 , the rotating excitation assembly 3 includes a blade 9 , a rotating shaft 10 , a pair of bearings 11 , and a rotating arm 12 , wherein: the blade 9 and the rotating arm 12 are fixed on the rotating shaft 10 , and the rotating shaft 10 It is rotatably connected to the support 4 through a pair of bearings 11 .

As shown in FIG. 8, it is a non-contact structure, the end of the rotating arm 12 of the rotary excitation assembly 3 and the end of the tail beam 8 of the fishbone beam 1 are respectively fixed to the excitation permanent magnet 13 and the excited permanent magnet 14, and the excitation permanent magnet 13 and the Contactless magnetic coupling is performed between the excited permanent magnets 14 . As shown in FIG. 9, it is a contact structure. The end of the rotating arm 12 of the rotary excitation assembly 3 and the end of the tail beam 8 of the fishbone beam 1 are respectively provided with a hemispherical excitation head 15 and an excited head 16. The hemispherical excitation head 15 Contact coupling with the head 16 to be excited. If the non-contact magnetic coupling mode is selected, a T-shaped permanent magnet mounting plate is provided at the end of the rotating arm 12 and the tail beam 8 .

Among them, a frequency modulation mass block 17 is fixed at the end of the fishbone beam comb tooth 7, so that the system natural frequency of the fishbone beam comb tooth 7 and the frequency modulation mass block 17 is the same as that of the tail beam 8 and the excited permanent magnet 14 (or the excited head 16). The ratio of frequencies is 2:1 or 3:1. The fishbone beam 1 can be processed by 3D printing, and the material with better elasticity is used. The rotating arm 12 is an array type rotating arm structure and a material with low rigidity is selected. The length of the rotating arm 12 and the mass of the excitation permanent magnet 13 (or the excitation head 15 ) are appropriately selected according to the application environment. The greater the product of the two, the greater the correlation between the wind speed and the excitation intensity.

As shown in Figure 10, the working principle of the present invention is: the wide speed domain wind drives the blade to rotate, the blade drives the rotating arm to rotate, and the rotating arm is magnetically coupled or contacted to excite the tail beam of the fishbone beam, and the magnetic coupling or contact excitation , make the tail beam of the fishbone beam vibrate, the piezoelectric sheet pasted on the outside of the fishbone beam produces compression and tension, and generates a large voltage through the piezoelectric effect, which can be stored or used directly. The rigidity of the rotating arm is small, so that at low wind speed, the reaction damping force generated by the fishbone beam is small, and the blade can rotate at low wind speed; the centrifugal force generated by the rotation can change the rigidity of the rotating arm. When the wind speed increases, the speed of the blade increases, and the centrifugal force Increase, the rigidity of the rotating arm increases, so that the excitation strength can be improved, that is, the self-adjusting excitation strength can be realized, and the excitation strength will not exceed a limit value. Under high wind speed, the fishbone beam will not produce excessive deformation and damage the piezoelectric At the same time, the array type rotating arm structure can amplify the excitation frequency, if four rotating arms are used, the excitation frequency is 4 times the rotation frequency; through magnetic coupling or contact excitation, the fishbone beam Tail boom vibration, the tail boom and the excited permanent magnet (or excited head) system with lower natural frequency are more easily excited and can capture more energy, the tail boom and the excited permanent magnet (or excited head) system pass through The resonance transmits energy to the fishbone beam comb teeth and frequency modulated mass block system with higher natural frequency; in the intermittent wind environment, the piezoelectric sheet will work at a higher frequency, and more mechanical energy can be converted into electrical energy, the fishbone beam comb The tooth structure can amplify the bending deformation of the central axis of the fishbone beam, so that the piezoelectric sheets pasted on both sides of the comb tooth structure produce greater tensile and compressive deformation, and generate a large voltage through the piezoelectric effect, which can be stored or used directly ; The length of the comb teeth of the fishbone beam decreases linearly from the fixed end to the free end, and the product of the reduction ratio and the increase ratio of the deflection of the central axis of the fishbone beam is approximately constant, so that all the comb teeth of the fishbone beam are bent when the fishbone beam is bent. The change degree of the adjacent teeth spacing is approximately the same, the deformation of the piezoelectric sheet is more uniform, and the tolerance of the piezoelectric sheet is improved.

The invention uses the comb tooth structure to amplify the bending deformation of the beam, that is, to amplify the deformation degree of the piezoelectric sheet, and can generate a larger voltage under the same working condition; the rotary motion is converted into vibration through magnetic coupling or contact type, so that the fishbone beam is It is easier to start vibrating at low wind speed, and it will not cause excessive deformation to damage the piezoelectric sheet at high wind speed, which expands its effective working frequency domain; through array excitation and resonance transmission, the excitation frequency is increased, and the performance of the energy harvester is improved. output average power.

The present invention is not limited by the above-mentioned embodiments, and any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principle of the present invention should be equivalent replacement methods, which are included in the present invention. within the scope of protection.

Claims (10)

1. a small wind energy harvester with frequency and displacement amplification, characterized in that: comprising a fishbone beam (1), a base (2), a rotary excitation assembly (3), and the fishbone beam (1) is provided with At the position between the base (2) and the rotational excitation assembly (3), the fixed end of the fishbone beam (1) is fixedly connected to the base (2), and the rotational excitation assembly (3) is rotatably connected On the support (4), the other end of the support (4) is fixedly connected to the base (2), and the rotation excitation assembly (3) is magnetically coupled with the free end of the fishbone beam (1) without contact The upper and lower sides of the fishbone beam (1) are symmetrically pasted with piezoelectric sheets (5); The tail beam (8) is composed of the fishbone beam comb teeth (7) which are arranged symmetrically up and down and at intervals on the center axis (6) of the fishbone beam, and the tail beam (8) is arranged on the free side of the fishbone beam (1). end, and is connected with the central axis (6) of the fishbone beam as a whole. 2. The small wind energy harvester with frequency and displacement amplification according to claim 1, characterized in that: the longitudinal length of the fishbone beam comb teeth (7) linearly decreases from the fixed end to the free end, and decreases The product of the ratio and the deflection increase ratio of the fishbone beam axis (6) is approximately constant. 3. The small wind energy harvester with frequency and displacement amplification according to claim 2, characterized in that: the rotary excitation assembly (3) comprises a blade (9), a rotating shaft (10), a pair of bearings (11) ), a rotating arm (12), the blade (9) and the rotating arm (12) are fixed on the rotating shaft (10), and the rotating shaft (10) can be connected through a pair of bearings (11) and a support (4). Rotary connection, the end of the rotating arm (12) and the end of the tail beam (8) are respectively fixed with an excitation permanent magnet (13) and an excited permanent magnet (14), the excitation permanent magnet (13) and the excited permanent magnet Contactless magnetic coupling is performed between (14). 4 . The small wind energy harvester with frequency and displacement amplification according to claim 3 , wherein the ends of the rotating arm ( 12 ) and the tail beam ( 8 ) are provided with T-shaped permanent magnet mounting plates. 5 . 5. The small wind energy harvester with frequency and displacement amplification according to claim 3, characterized in that: a frequency modulation mass block (17) is fixed at the end of the fishbone beam comb teeth (7), and the fishbone beam The ratio of the system natural frequency of the comb teeth (7) and the frequency modulated mass (17) to the system natural frequency of the tail beam (8) and the excited permanent magnet (14) is 2:1 or 3:1. 6. A small wind energy harvester with frequency and displacement amplification, characterized in that it comprises a fishbone beam (1), a base (2), and a rotational excitation assembly (3), and the fishbone beam (1) is provided with At the position between the base (2) and the rotational excitation assembly (3), the fixed end of the fishbone beam (1) is fixedly connected to the base (2), and the rotational excitation assembly (3) is rotatably connected On the support (4), the other end of the support (4) is fixedly connected to the base (2), and the rotation excitation component (3) is contact-coupled with the free end of the fishbone beam (1), so Piezoelectric sheets (5) are symmetrically pasted on the upper and lower sides of the fishbone beam (1); (8) composition, the said fishbone beam comb teeth (7) are symmetrically arranged up and down and spaced on the center axis (6) of the fishbone beam, and the tail beam (8) is arranged on the free end of the fishbone beam (1), and is connected with the central axis (6) of the fishbone beam as a whole. 7. The small wind energy harvester with frequency and displacement amplification according to claim 6, characterized in that: the longitudinal length of the fishbone beam comb teeth (7) linearly decreases from the fixed end to the free end, and decreases The product of the ratio and the deflection increase ratio of the fishbone beam axis (6) is approximately constant. 8. The small wind energy harvester with frequency and displacement amplification according to claim 7, characterized in that: the rotary excitation assembly (3) comprises a blade (9), a rotating shaft (10), a pair of bearings (11) ), a rotating arm (12), the blade (9) and the rotating arm (12) are fixed on the rotating shaft (10), and the rotating shaft (10) can be connected through a pair of bearings (11) and a support (4). Rotary connection, the end of the rotating arm (12) and the end of the tail beam (8) are respectively provided with a hemispherical excitation head (15) and an excited head (16), the hemispherical excitation head (15) and the excited head Contact coupling between (16). 9 . The small wind energy harvester with frequency and displacement amplification according to claim 8 , characterized in that: a frequency modulation mass block ( 17 ) is fixed at the end of the fishbone beam comb teeth (7 ), and the fishbone beam The ratio of the system natural frequency of the comb teeth (7) and the FM mass (17) to the system natural frequency of the tail beam (8) and the excited head (16) is 2:1 or 3:1. 10. The small wind energy harvester with frequency and displacement amplification according to claim 9, characterized in that: the fishbone beam (1) is made of elastic material and processed by 3D printing, and the rotating arm (1). 12) It is made of array type rotating arm structure and selected materials with lower rigidity.

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