Piezoelectric electromagnetic coupling vibration energy collection device based on spring nonlinear amplification

Abstract

The utility model belongs to the field of energy collection, and particularly relates to a piezoelectric electromagnetic coupling vibration energy collection device based on spring nonlinear amplification, which comprises a spring base and a transduction cantilever beam base connected with the spring base, and four groups of transduction cantilever beams are mounted on the transduction cantilever beam base. Each group of transduction cantilever beams is connected with the transduction cantilever beam base through a group of clamping devices, each group of transduction cantilever beams comprises a metal sheet, a piezoelectric sheet is arranged in the middle of the metal sheet, and an electromagnetic transducer is arranged at the end part of the metal sheet. The original amplitude can be amplified, the typical value of the vibration frequency of the hydro-generator stator is 50 Hz, the structure is simple, installation is easy, and the self-power-supply possibility of large hydro-generator stator temperature monitoring distribution points can be greatly improved.

Description

Technical Field

[0001] This application belongs to the field of energy harvesting, and particularly relates to a piezoelectric-electromagnetic coupled vibration energy harvesting device based on spring nonlinear amplification. Background Art

[0002] As a large energy country, although China's installed power generation capacity has increased, traditional fossil fuel power generation still accounts for a large proportion. To achieve the goals of carbon peak and carbon neutrality and promote the construction of ecological civilization, it is crucial to develop clean energy. Given the significant topographical differences between the east and west of China and its rich water resources, hydropower, as a clean and renewable energy form, has unique development advantages. To ensure the safety and stability of the hydropower industry, it is particularly important to monitor the operating state of large hydro-generator sets, especially their stators.

[0003] The stator of a large hydro-generator consists of multiple components, all of which are core components of the generator. A large amount of heat is generated during the operation of the generator, so it is necessary to strictly control its temperature rise to ensure the safe operation of the equipment. Temperature detection points need to be set in key areas such as the stator core and coils to monitor the unit status in real time. Currently, there are various stator temperature measurement methods available, including RFID temperature measurement, infrared temperature measurement, and optical fiber temperature measurement.

[0004] However, the temperature monitoring points are installed inside the hydro-generator, making it difficult to perform maintenance. Since traditional monitoring points rely on battery power supply, once the battery runs out, the points will fail. To solve this problem, the fundamental solution is to solve the energy supply problem. The points should be able to collect stray energy in the environment and achieve self-power supply. In the working environment of a hydro-generator, mechanical vibration energy is abundant, providing the possibility for self-power supply of the points. To achieve vibration energy harvesting, researchers have proposed a large number of piezoelectric vibration energy harvesting devices or electromagnetic vibration energy harvesting devices (such as Chinese Patent Authorization Number: CN215871229U, Chinese Patent Application Number: CN114977884A, Chinese Patent Application Number: CN112234791A). Although these devices can achieve vibration energy harvesting, the harvesting method is single and the energy conversion efficiency is not high. Some researchers have also proposed piezoelectric-electromagnetic coupled vibration energy harvesting devices and methods (such as Chinese Patent Authorization Number: CN 112491297B), but they have complex structures, are inconvenient to install, and cannot amplify the original input excitation, resulting in poor performance when used in small amplitude situations. Summary of the Invention

[0005] To overcome the above problems existing in the existing technologies, a piezoelectric-electromagnetic coupled vibration energy harvesting device based on spring non-linear amplification is now proposed. This device can solve the problems of low conversion efficiency, single energy harvesting method, inability to amplify the original input excitation, and inability to stably supply energy to the stator temperature monitoring points of large hydro-generators for a long time in the existing vibration energy harvesting devices.

[0006] To achieve the above technical effects, the solution of this application is as follows:

[0007] A piezoelectric-electromagnetic coupled vibration energy harvesting device based on spring non-linear amplification, including a spring base and a transducer cantilever beam base connected thereto. Four groups of transducer cantilever beams are installed on the transducer cantilever beam base. Each group of transducer cantilever beams is connected to the transducer cantilever beam base through a set of clamping devices. Each group of transducer cantilever beams includes a metal sheet, a piezoelectric sheet is arranged in the middle of the metal sheet, and an electromagnetic transducer is arranged at the end of the metal sheet.

[0008] Further, the four groups of transducer cantilever beams are evenly distributed on the transducer cantilever beam base, and the interval between adjacent transducer cantilever beams is 90°.

[0009] Further, each electromagnetic transducer includes a first magnet, a second magnet, a copper coil and a magnet barrel. The first magnet is adhesively fixed to the inner bottom of the magnet barrel. The second magnet is opposite to the first magnet with the same pole, and the second magnet thus floats. The copper coil is wound around the outside of the magnet barrel.

[0010] Still further, the first magnet and the second magnet are both annular magnets and are both permanent magnets.

[0011] Further, the metal sheet is tin bronze, the piezoelectric sheet is adhesively attached to the metal sheet, and the geometric centers of the metal sheet and the piezoelectric sheet are on a vertical straight line.

[0012] Further, the piezoelectric sheet is made of PZT-5H material and the working mode is d31.

[0013] Further, the outer circle of the magnet barrel is tangent to the narrower side of the outer extension of the metal sheet.

[0014] Further, the clamping device includes a cover plate. The cover plate is provided with a first cover plate through hole and a second cover plate through hole. The first hexagon socket head bolt passes through the first cover plate through hole, and the second hexagon socket head bolt passes through the second cover plate through hole. The first hexagon socket head bolt is matched with the first locknut, and the second hexagon socket head bolt is matched with the second locknut.

[0015] Further, the spring base includes a device fixing plate, a first spring and a second spring. The two ends of the first spring and the second spring are respectively adhered to the device fixing plate and the transducer cantilever beam base, and the wire diameters are all specially designed;

[0016] Furthermore, the materials of the first spring and the second spring are both ASTM1065.

[0017] Furthermore, through holes one and two are respectively opened on both sides of the center line parallel to the short side of the device fixing plate for fixing the whole device.

[0018] Compared with the prior art, the beneficial effects of the present application are as follows:

[0019] 1. The present application can amplify the original amplitude (the typical value of the vibration frequency of the stator of a hydro-generator is 50 Hz), and has a simple structure and is easy to install, which can greatly improve the possibility of self-power supply for the temperature monitoring points of the stator of a large hydro-generator.

[0020] 2. The present application overcomes the problems of low energy conversion efficiency of a single-mode vibration energy harvesting device, inability to amplify the original input excitation, and inability to stably supply energy to the temperature monitoring points of the stator of a large hydro-generator for a long time. Four groups of transducer cantilever beams are integrated in a set of vibration energy harvesting devices. Each group of transducer cantilever beams includes a piezoelectric cantilever beam and a set of electromagnetic transducers, which can simultaneously carry out piezoelectric and electromagnetic vibration energy harvesting. In addition, a spring is used to amplify the original input amplitude and mounting holes are reserved on the base.

[0021] 3. The device of the present application is easy to install, stable and reliable, and can improve the mechanical energy-electric energy conversion ratio of unit vibration energy input. It is especially suitable for powering micro-power consumption devices that need to achieve self-power supply under sufficient mechanical vibration conditions during service. Description of the Drawings

[0022] Figure 1 It is a schematic diagram of the overall structure of the present application.

[0023] Figure 2 It is a schematic diagram of the structure of the transducer cantilever beam of the present application.

[0024] Figure 3 It is a top view of the electromagnetic transducer of the present application.

[0025] Figure 4 It is a sectional view of the electromagnetic transducer of the present application in the A-A direction.

[0026] Figure 5 It is a schematic diagram of a single clamping device fixing a single transducer cantilever beam of the present application.

[0027] Figure 6 It is a top view of the cover plate of the present application.

[0028] Figure 7 It is a top view of the base of the transducer cantilever beam of the present application.

[0029] Figure 8 It is a top view of the device fixing plate of the present application.

[0030] Figure 9 This is a schematic diagram of the spring base structure of the present application.

[0031] In the figure, 1 is the spring base, 2 is the transducer cantilever beam, 3 is the transducer cantilever beam base, 4 is the clamping device, 11 is the device fixing plate, 12 is the first spring, 13 is the second spring, 21 is the metal sheet, 22 is the piezoelectric sheet, 23 is the electromagnetic transducer, 31 is the first transducer cantilever beam base through hole, 32 is the second transducer cantilever beam base through hole, 41 is the cover plate, 42 is the first hexagon socket head cap screw, 43 is the first lock nut, 44 is the second hexagon socket head cap screw, 45 is the second lock nut, 111 is the first through hole, 112 is the second through hole, 231 is the first magnet, 232 is the second magnet, 233 is the copper coil, 234 is the magnet barrel, 411 is the first cover plate through hole, 412 is the second cover plate through hole. Detailed implementation manners

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. Usually, the components of the embodiments of the present application described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application claimed, but merely represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without making creative efforts fall within the scope of protection of the present application.

[0034] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0035] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "upper", "vertical", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship when the product of this application is normally placed, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present application. In addition, the terms "first", "second", etc. are only used for descriptive distinction and cannot be understood as indicating or implying relative importance.

[0036] In the description of the present application, it should also be noted that, unless otherwise clearly specified and defined, the terms "arrangement", "installation", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0037] Embodiment 1

[0038] As Figures 1-9 shown, a piezoelectric-electromagnetic coupling vibration energy harvesting device based on spring non-linear amplification includes a spring base 1 and a transducer cantilever beam base 3 connected thereto. Four groups of transducer cantilever beams 2 are installed on the transducer cantilever beam base 3. Each group of transducer cantilever beams 2 is connected to the transducer cantilever beam base 3 through a set of clamping devices 4. Each group of transducer cantilever beams 2 includes a metal sheet 21. A piezoelectric sheet 22 is arranged in the middle of the metal sheet 21, and an electromagnetic transducer 23 is arranged at the end of the metal sheet 21.

[0039] The four groups of transducer cantilever beams 2 are evenly distributed on the transducer cantilever beam base 3, and the interval between adjacent transducer cantilever beams 2 is 90°.

[0040] Each electromagnetic transducer 23 includes a first magnet 231, a second magnet 232, a copper coil 233, and a magnet barrel 234. The first magnet 231 is adhesively fixed to the inner bottom of the magnet barrel 234. The second magnet 232 is opposite to the first magnet 231 with the same pole, so the second magnet 232 floats. The copper coil 233 is wound around the outside of the magnet barrel 234. The first magnet 231 and the second magnet 232 are both annular magnets and both are permanent magnets.

[0041] The metal sheet 21 is tin bronze. The piezoelectric sheet 22 is adhesively attached to the metal sheet 21, and the geometric centers of the metal sheet 21 and the piezoelectric sheet 22 are on a vertical straight line.

[0042] The piezoelectric sheet 22 is made of PZT-5H material, and the working mode is d31. The d31 mode means that the stress direction is inconsistent with the electric field direction.

[0043] The outer circle of the magnet barrel is tangent to the narrower side of the outer extension of the metal sheet 21. The direct tangency between the two is convenient for positioning and makes the positional relationship between the four groups of magnet barrels and the metal sheet 21 consistent.

[0044] The clamping device 4 includes a cover plate 41. The cover plate 41 is provided with a first cover plate through hole 411 and a second cover plate through hole 412. A first hexagon socket head bolt 42 passes through the first cover plate through hole 411, and a second hexagon socket head bolt 44 passes through the second cover plate through hole 412. The first hexagon socket head bolt 42 cooperates with a first locknut 43, and the second hexagon socket head bolt 44 cooperates with a second locknut 45.

[0045] The spring base 1 includes a device fixing plate 11, a first spring 12, and a second spring 13. The two ends of the first spring 12 and the second spring 13 are respectively adhered to the device fixing plate 11 and the transducer cantilever beam base 3. The first spring 12 and the second spring 13 are identical in material and size, and their wire diameters are specially designed. The materials of the first spring 12 and the second spring 13 are both ASTM1065, and they can resonate at 50 Hz to increase the original input excitation.

[0046] Through holes 111 and 112 are respectively opened on both sides of the center line parallel to the short side of the device fixing plate 11 for fixing the entire device.

[0047] This application can amplify the original amplitude (the typical value of the vibration frequency of the stator of a hydro-generator is 50 Hz). Moreover, it has a simple structure and is easy to install, which can greatly improve the possibility of self-power supply for the temperature monitoring points of the stator of a large hydro-generator. This application overcomes the problems of low energy conversion efficiency of a single-mode vibration energy harvesting device, inability to amplify the original input excitation, and inability to stably supply power to the temperature monitoring points of the stator of a large hydro-generator for a long time. Four groups of transducer cantilever beams 2 are integrated in a set of vibration energy harvesting devices. Each group of transducer cantilever beams 2 includes a piezoelectric cantilever beam and a set of electromagnetic transducers 23, and piezoelectric and electromagnetic vibration energy harvesting can be carried out simultaneously. In addition, the original input amplitude is amplified by springs and mounting holes are reserved on the base. This device is simple to install, stable and reliable, and can improve the mechanical energy-electric energy conversion ratio of unit vibration energy input. It is especially suitable for powering micro-power consumption devices that need to achieve self-power supply under sufficient mechanical vibration conditions during service.

[0048] Embodiment 2

[0049] Refer to Figure 1 、 Figure 4 、 Figure 9, the piezoelectric-electromagnetic coupling vibration energy harvesting device based on spring non-linear amplification of the present application includes a spring base 1, a transducer cantilever beam 2, a transducer cantilever beam base 3, and a clamping device 4. The wire diameters of the first spring 12 and the second spring 13 are both specially designed to resonate when the input excitation is 50 Hz. Specifically, the materials of the first spring 12 and the second spring 13 are both ASTM1065. The present application includes 4 groups of transducer cantilever beams 2. The electromagnetic transducers 23 on each group of transducer cantilever beams 2 can serve as the end mass blocks of the piezoelectric cantilever beam composed of the metal sheet 21 and the piezoelectric sheet 22. The material of the metal sheet 21 in the present application is tin bronze, and the material of the piezoelectric sheet 22 is PZT 5H working in the d31 mode. During vibration, the metal sheet 21 generates simple harmonic jitter, and thus the piezoelectric sheet 22 deforms and starts to generate electricity according to the direct piezoelectric effect; the displacements and phases of the second magnet 232 and the copper coil 233 in the electromagnetic transducer 23 are different, so the copper coil 233 cuts the magnetic induction lines of the second magnet 232 and generates electricity.

[0050] Referring to Figures 2-4 , each electromagnetic transducer is composed of a first magnet 231, a second magnet 232, a copper coil 233, and a magnet barrel 234. Both the first magnet 231 and the second magnet 232 are annular magnets, and the first magnet 231 is adhered to the inner bottom of the magnet barrel 234. The first magnet 231 and the second magnet 232 are opposite in the same pole. Due to the repulsion between like magnets, the second magnet 232 is magnetically levitated. Both the first magnet 231 and the second magnet 232 are annular magnets and are both permanent magnets. The outer circle of the magnet barrel 234 is tangent to the narrower side of the outer extension of the metal sheet 21.

[0051] Referring to Figure 5 , Figure 6 , the front end of each transducer cantilever beam 2 is clamped between the cover plate 41 and the transducer cantilever beam base 3. The M3x30 first hexagon socket head cap screw 42 in each group of clamping devices 4 passes through the first cover plate through hole 411 and the first transducer cantilever beam base through hole 31 and is locked by the M3 first locknut 43. The M3x30 hexagon socket head cap screw two 44 passes through the second cover plate through hole 412 and the second transducer cantilever beam base through hole 32 and is locked by the M3 second locknut 45. Because bolt and nut are used for clamping and fixing, the clamped position of the transducer cantilever beam can be changed according to the working conditions. Since the present application is mostly used in the occasion full of mechanical vibration, using locknuts can firmly fix each transducer cantilever beam.

[0052] Referring to Figure 8 , through holes one 111 and through holes two 112 are respectively opened on both sides of the center line parallel to the short side of the device fixing plate, which can be used to fix the whole device on the vibration excitation source.

[0053] The foregoing are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A piezoelectric-electromagnetic coupled vibration energy harvesting device based on spring non-linear amplification, characterized in that: It includes a spring base (1) and a transducer cantilever beam base (3) connected thereto. Four groups of transducer cantilever beams (2) are installed on the transducer cantilever beam base (3). Each group of transducer cantilever beams (2) is connected to the transducer cantilever beam base (3) through a set of clamping devices (4). Each group of transducer cantilever beams (2) includes a metal sheet (21). A piezoelectric sheet (22) is arranged in the middle of the metal sheet (21), and an electromagnetic transducer (23) is arranged at the end of the metal sheet (21).

2. The piezoelectric electromagnetic coupling vibration energy harvesting device based on spring non-linear amplification according to claim 1, wherein: The four groups of transducer cantilever beams (2) are evenly distributed on the transducer cantilever beam base (3), and the interval between adjacent transducer cantilever beams (2) is 90°.

3. The piezoelectric electromagnetic coupling vibration energy harvesting device based on spring nonlinear amplification according to claim 1, characterized in that: Each electromagnetic transducer (23) includes a first magnet (231), a second magnet (232), a copper coil (233) and a magnet barrel (234). The first magnet (231) is adhesively fixed to the inner bottom of the magnet barrel (234). The second magnet (232) is opposite to the first magnet (231) with the same pole, so the second magnet (232) floats. The copper coil (233) is wound around the outside of the magnet barrel (234).

4. The piezoelectric electromagnetic coupling vibration energy harvesting device based on spring nonlinear amplification according to claim 3, characterized in that: Both the first magnet (231) and the second magnet (232) are annular magnets and are both permanent magnets.

5. The piezoelectric electromagnetic coupling vibration energy harvesting device based on spring non-linear amplification according to claim 1, characterized in that: The metal sheet (21) is tin bronze. The piezoelectric sheet (22) is adhesively connected to the metal sheet (21), and the geometric centers of the metal sheet (21) and the piezoelectric sheet (22) are on the same vertical line.

6. The piezoelectric electromagnetic coupling vibration energy harvesting device based on spring nonlinear amplification according to claim 1, wherein: The piezoelectric sheet (22) is made of PZT-5H material and its working mode is d31.

7. The piezoelectric-electromagnetic coupled vibration energy harvesting device based on spring non-linear amplification according to claim 1, wherein: The clamping device (4) includes a cover plate (41). A first cover plate through hole (411) and a second cover plate through hole (412) are arranged on the cover plate (41). A first hexagon socket head bolt (42) passes through the first cover plate through hole (411), and a second hexagon socket head bolt (44) passes through the second cover plate through hole (412). The first hexagon socket head bolt (42) cooperates with a first locknut (43), and the second hexagon socket head bolt (44) cooperates with a second locknut (45).

8. The piezoelectric-electromagnetic coupled vibration energy harvesting device based on spring non-linear amplification according to claim 1, wherein: The spring base (1) includes a device fixing plate (11), a first spring (12) and a second spring (13). The two ends of the first spring (12) and the second spring (13) are adhesively connected to the device fixing plate (11) and the transducer cantilever beam base (3) respectively.

9. The piezoelectric electromagnetic coupling vibration energy harvesting device based on spring non-linear amplification according to claim 8, characterized in that: The materials of both the first spring (12) and the second spring (13) are ASTM1065.

10. The piezoelectric electromagnetic coupling vibration energy harvesting device based on spring nonlinear amplification according to claim 1, characterized in that: Through holes one (111) and two (112) are respectively opened at 64 mm on both sides of the center line parallel to the short side of the device fixing plate (11) for fixing the whole device.

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