A railway track displacement piezoelectric energy harvester and method of use

Abstract

This invention discloses a railway track-to-track displacement piezoelectric energy harvesting device and its usage method, comprising a housing, a height-adjustable load-bearing structure, a vibration force transmission structure, and an energy conversion structure. The height-adjustable load-bearing structure includes an upper load-bearing plate and a height-adjustable support composed of a threaded base, a single-headed hexagonal column, and a flange nut. The vibration force transmission structure includes a force transmission rod and a lower load-bearing plate. The energy conversion structure includes a cymbal-type force amplification frame and a piezoelectric stack, with the piezoelectric stack embedded in the cymbal-type force amplification frame and fixed to a fixing screw via limiting washers, forming a whole connected between the upper and lower load-bearing plates. This invention uses a cymbal-type force amplification frame to achieve force amplification, a bending-pull working mode to improve stability, a height-adjustable support to accommodate track-to-track distances of 60-80mm, and an overall low-stiffness design to reduce the impact on the dynamic characteristics of the rails. This invention has a stable structure, high output efficiency, and can provide a continuous and stable power supply for track-to-track wireless sensors.

Description

Technical Field

[0001] This invention relates to the field of piezoelectric energy harvesting devices, and more particularly to railway track displacement type energy harvesting devices. Background Technology

[0002] In recent years, China's railway network, especially high-speed railways, has achieved leapfrog development, with continuous growth in operational scale and passenger traffic. However, ensuring the operational safety of this vast network is facing increasingly severe challenges. As a key technology for monitoring the health of railway infrastructure, the large-scale deployment of wireless sensor networks has long been constrained by power supply bottlenecks. Traditional battery-powered systems suffer from limited battery life, high replacement costs, and a heavy environmental burden from discarded batteries, making it difficult to meet the long-term stable power supply needs of a large number of distributed sensor nodes along the railway line. On the other hand, railway rails contain a huge amount of continuous vibration energy under the action of moving trains. Currently, this energy is mainly dissipated as heat through rail damping or fastening systems and is not effectively utilized. Therefore, if the vibration energy of rails can be efficiently captured and converted into electrical energy through piezoelectric energy harvesting devices to provide a continuous and stable power supply for inter-rail wireless sensors, it will become an ideal technical approach to solve the above-mentioned power supply problems.

[0003] Common cantilever piezoelectric energy harvesting devices typically have low output power density, mostly limited to the microwatt (µW) level. Furthermore, because their cantilever structure is subjected to frequent bending vibrations, excessive deformation can easily lead to fatigue fracture of the piezoelectric stack. This not only restricts the geometric design of the cantilever beam but also further limits the overall output power of the energy harvesting device. Therefore, to improve energy conversion efficiency, it is necessary to optimize and improve the structural form of piezoelectric energy harvesting devices.

[0004] Unlike piezoelectric cantilever beams, the external force in a piezoelectric stack acts directly on the surface of the piezoelectric material, and the direction of force is consistent with the polarization direction, thus significantly improving energy conversion efficiency. Furthermore, during vibration, the piezoelectric stack is typically under pressure, giving it higher load-bearing capacity and stability. The invention patent application CN 111726035 A, published on June 10, 2020, entitled "A Tuned Mass Piezoelectric Energy Harvesting Device and Its Manufacturing Method," discloses a piezoelectric stack energy harvesting device. This energy harvesting device avoids the shortcomings of cantilever beam energy harvesting devices by using a piezoelectric stack, significantly increasing output power. However, this device uses a resonant power generation method, which has a narrow operating bandwidth, making it difficult to cope with the wide-frequency working environment of rails, and its performance is poor in detuned states.

[0005] The displacement-driven design can effectively broaden the operating frequency band. The invention patent "Piezoelectric stack compression generator," published on December 1, 2011, with publication number "US2011 / 0291526A1," discloses a piezoelectric stack energy harvesting device. This device uses a displacement-driven design, effectively solving the aforementioned problems. However, its use requires drilling into the railway track, affecting the overall railway structure, and it does not consider the impact of the installed energy harvesting device on the rails. To address this issue, the invention patent application "A piezoelectric energy harvesting device for rails and its usage method," published on June 21, 2024, with authorization publication number "CN 118232735 A," solves the problem of needing to drill into the railway track. It only requires a spring to connect the rail and the energy harvesting device. However, the piezoelectric stack is limited by the spring force; when the force is too large, it affects the dynamic characteristics of the rail, and when the stiffness is too small, it reduces the output power of the energy harvesting device.

[0006] For the reasons mentioned above, existing rail energy harvesting devices have many problems, such as low output power, poor stability, complex installation, and significant impact on rails. Summary of the Invention

[0007] To overcome the shortcomings of the prior art, this invention provides a railway track-to-track displacement piezoelectric energy harvesting device, solving problems such as insufficient output power, poor adaptability to track-to-track distance, complex structure, difficult manufacturing, and poor long-term stability. Through the precise integration of various components, a railway track-to-track displacement piezoelectric energy harvesting device is finally assembled. Specifically, it includes: A railway track displacement type piezoelectric energy harvesting device includes a shell, a height-adjustable load-bearing structure, a vibration force transmission structure, and an energy conversion structure; The height-adjustable load-bearing structure includes: an upper load-bearing plate and a height-adjustable support, wherein the height-adjustable support extends through the bottom of the shell; The supporting body of the height-adjustable load-bearing structure device comprises: an upper load-bearing plate and a height-adjustable support assembly. The height-adjustable support assembly specifically includes a threaded base, a single-headed hexagonal column, and a flange nut; The threaded base is fixedly installed at the four corners of the bottom of the housing. The lower end of the single-headed hexagonal column is screwed into the threaded base, and the upper end passes through the preset mounting hole of the upper bearing plate. Finally, the upper bearing plate is pressed and fixed by tightening the flange nut on the single-headed hexagonal column, thereby realizing the adjustment of the overall height of the support structure. The height-adjustable support allows the piezoelectric energy harvesting device to operate at a height of 60mm-80mm. Preferably, the thickness of both the upper and lower support plates is 10mm, the cross-sectional area of ​​the upper support plate is 166mm×60mm, the diameter of the height-adjustable support holes reserved around the upper support plate is 10mm, the diameter of the four connection holes for the energy conversion structure reserved in the upper and lower support plates is 4mm, and the diameter of the holes for the force transmission rod is 12mm. The vibration transmission structure includes a force transmission rod and a lower bearing plate, and the force transmission rod and the lower bearing plate are tightly connected by a spiral. The vibration transmission structure is built into the inner cavity of the housing, and the transmission rod passes through the top of the housing; Preferably, the force transmission rod has a diameter of 10mm and a length of 60mm, wherein the bottom of the force transmission rod has a 10mm thread for connecting with the lower bearing plate; The longitudinal displacement of common railway rails generated by the vibration when a train passes is about 3mm. In view of this characteristic, the working vibration range of this invention is designed to be 5mm, which not only fully covers the vibration amplitude range of the actual rail, but also retains appropriate design redundancy, ensuring that the energy conversion structure is always in the best working state under complex and variable line conditions, and achieving efficient and stable energy capture.

[0008] The energy conversion structure includes: a cymbal force amplification frame and a piezoelectric stack section; The piezoelectric stack is built into the cymbal force amplification frame, the upper end of the overall energy conversion structure is mounted on the upper support plate, and the lower end of the energy conversion structure is mounted on the lower support plate; When the force transmission rod is subjected to vibration energy from the upper rail, it transmits the energy to the lower bearing plate. The upper bearing plate is fixed to the energy harvesting device support. The force transmission rod moves repeatedly in a straight line along the axial direction due to the vibration of the rail. The lower bearing plate moves repeatedly in a straight line due to the influence of the force transmission rod, causing the energy conversion structure to be repeatedly stretched and reset along the axial direction. The piezoelectric stack can then convert mechanical energy into electrical energy. The energy conversion structure includes four cymbal force amplification frames and four piezoelectric stacks; The piezoelectric stacks are connected in parallel sequentially. Preferably, the cymbal force amplification frame has a length of 100mm and a height of 18mm; The piezoelectric stack is arranged in a columnar shape and is installed in parallel. The piezoelectric stack includes a protective layer made of ordinary ceramic sheets, an electrode layer made of copper electrode sheets, and a piezoelectric layer made of piezoelectric ceramic sheets. Optionally, the protective layer has a single-layer thickness of 3mm and a cross-sectional area of ​​8mm×8mm; the electrode layer has a single-layer thickness of 0.1mm and a cross-sectional area of ​​8mm×8mm; and the piezoelectric layer has a single-layer thickness of 3mm and a cross-sectional area of ​​8mm×8mm. During the final assembly process, the support structure is first adjusted to the predetermined height and fixed. Then, the upper end of the energy conversion structure is connected to the upper bearing plate and the lower end is connected to the lower bearing plate. Next, the lower bearing plate and the force transmission rod are assembled into one unit. Finally, the assembly is placed into the inner cavity of the shell, so that the force transmission rod passes through the through hole at the top of the shell. The supporting structure, energy conversion structure and vibration transmission structure are thus integrated into one unit to form a complete energy harvesting device, which is then built into the housing. Optionally, the housing includes: a top cover and a body; The housing is rectangular in shape, with a removable top cover installed on the top of the housing, and four height-adjustable support slots reserved at the bottom of the housing. The top cover is rectangular in shape. Optionally, the housing is made of aluminum alloy; This device is installed between railway tracks. The top of the force transmission rod contacts the lower surface of the rail, and the housing is supported on the surface of the track bed or sleeper by a threaded base and a single-headed hexagonal column.

[0009] When multiple energy harvesting devices are arranged together, multiple devices can be deployed at intervals between adjacent sleepers along the longitudinal direction of the rail. Each device harvests energy independently, thereby realizing distributed power supply for wireless sensor networks in long-distance sections.

[0010] The present invention also provides a method for harvesting vibration energy between railway tracks, comprising the following steps: The support height of the adjustment device is adapted to the track spacing; the device is installed between the railway tracks so that the force transmission rod contacts the rail; when a train passes, the rail vibration is transmitted to the force transmission rod; the force transmission rod drives the lower bearing plate to reciprocate axially; the energy conversion structure is repeatedly stretched and reset between the upper and lower bearing plates; the piezoelectric stack generates electrical energy during deformation; the electrical energy output from multiple energy conversion structures connected in parallel supplies the wireless sensor.

[0011] The following are included before installation: A further improvement to the technical solution of the present invention is that: the adjustment amount of the single-head hexagonal column is determined according to the distance between the rails before installation; and the upper bearing plate is locked to the set height by means of flange nuts.

[0012] A further improvement to the technical solution of this invention is that: the tightness of the flange nuts is checked periodically; the stability of the power output is monitored; and the height of the device is adjusted as needed to adapt to changes in track gauge.

[0013] Compared with the prior art, the present invention has the following significant technical effects: This invention employs a force amplification mechanism combining a cymbal-type force amplification frame and a piezoelectric stack, efficiently amplifying the vertical force generated by the vertical deformation of the rail and converting it into radial axial pressure on the piezoelectric stack, significantly improving the electromechanical conversion efficiency per unit vibration input. Simultaneously, the four sets of energy conversion structures are symmetrically arranged in parallel, enabling effective superposition of output currents under the same vibration conditions. The overall output power is significantly higher than that of traditional cantilever beam or single-stack energy harvesting devices, meeting the power requirements for long-term stable operation of inter-rail wireless sensors.

[0014] This invention employs a tension-bending working mode. By applying pre-displacement treatment to the device beforehand, it keeps the device under tension at all times, effectively avoiding the instability problem caused by excessive pressure in traditional piezoelectric energy harvesting devices. Simultaneously, this working mode ensures that the piezoelectric stack is always subjected to compressive stress rather than tensile stress, effectively avoiding the brittle fracture problem that easily occurs in piezoelectric ceramics under tensile stress. The cymbal-type force amplification frame provides all-around enclosure and limiting protection for the piezoelectric stack. Combined with the double locking structure of limiting gaskets and fixing screws, this ensures the positional stability and mechanical integrity of the piezoelectric stack under high-frequency vibration conditions, significantly extending the service life of the power generation unit.

[0015] This invention employs an overall low-rigidity design. The height-adjustable support, consisting of a threaded base, a single-headed hexagonal column, and a flange nut, forms a flexible support. Its overall stiffness is significantly lower than that of traditional rigid installation structures, effectively avoiding interference from the energy harvesting device on the rail's vibration characteristics and ensuring the safety and stability of train operation. Furthermore, by adjusting the screw-in depth of the single-headed hexagonal column, the device's working height can be continuously adjusted within the range of 60mm to 80mm, flexibly adapting to different rail types and track conditions for varying track spacing requirements, demonstrating excellent versatility and engineering adaptability.

[0016] This invention eliminates the need for destructive operations such as drilling or grooving on the rails or track bed; reliable fixation is achieved solely through mechanical contact and the device's own weight. The top of the force transmission rod makes natural contact with the lower surface of the rail, and the housing is supported on the track bed or sleeper surface by a threaded base and a single-headed hexagonal column. The assembly and disassembly process is simple and quick, requiring only one person or a single tool for maintenance and replacement, significantly reducing installation and commissioning difficulty and life-cycle maintenance costs. When multiple energy harvesting devices are deployed together, they can be equally spaced between adjacent sleepers, enabling distributed power supply for a wireless sensor network over long distances.

[0017] All major functional modules of this invention, including the piezoelectric power generation unit, the load-bearing support structure, and the force transmission structure, adopt standardized interfaces and detachable connection methods, supporting rapid on-site disassembly and independent replacement. This modular design not only facilitates fault diagnosis and component upgrades but also provides a convenient technical path for subsequent power expansion or performance optimization. Attached Figure Description

[0018] To clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings in the following description are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a 3D structural schematic diagram of the displacement-type piezoelectric energy harvesting device in an embodiment of the present invention; Figure 2 This is an exploded view of the displacement-type piezoelectric energy harvesting device in an embodiment of the present invention; Figure 3 This is a schematic diagram of the support base structure of the displacement-type piezoelectric energy harvesting device in an embodiment of the present invention; Figure 4 This is a schematic diagram of the power generation unit structure of the displacement-type piezoelectric energy harvesting device in an embodiment of the present invention; Figure 5 This is an exploded view of the power generation unit structure of the displacement-type piezoelectric energy harvesting device in an embodiment of the present invention; Figure 6 A schematic diagram of a piezoelectric stack provided by the present invention; Figure 7 This is a schematic diagram illustrating the electrical connection relationships between multiple piezoelectric stacks provided by the present invention; Figure 8 This is a schematic diagram of the track installation of a single energy harvesting device provided by the present invention; Figure 9 This is a schematic diagram of the track installation of multiple energy harvesting devices provided by the present invention.

[0020] In the diagram: 1. Upper support plate; 2. Single-headed hexagonal post; 3. Flange nut; 4. Threaded base; 5. Force transmission rod; 6. Lower support plate; 7. Cymbal force amplification frame; 8. Piezoelectric stack; 9. Limiting washer; 10. Fixing screw; 11. Internal hexagonal screw; 12. Fixing nut. Detailed Implementation

[0021] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals always denote the same or similar elements or elements having the same or similar functions. The embodiments described with reference to the accompanying drawings are exemplary and used to explain the present invention, and should not be construed as limiting the present invention.

[0022] Those skilled in the art will understand that, unless otherwise stated, the singular forms “a,” “an,” “the,” and “the” used herein may also include plural forms. It should be further understood that the word “comprising” as used in the specification means the presence of the stated features, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. It should be understood that when references are made to an element being “connected” or “coupled” to another element, it may be a direct connection or coupling, or there may be an intermediate element. Furthermore, “connected” or “coupled” as used herein may include wireless connections or couplings. The term “and / or” as used includes any one and all combinations of the listed related items.

[0023] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein have the meaning commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be interpreted as having the same meaning as they do in the relevant technical context and in the context of this specification, and should not be interpreted in an idealized or overly formal manner unless specifically defined herein.

[0024] Existing rail energy harvesting devices suffer from numerous problems, such as low output power, poor stability, complex installation, and short lifespan of the power generation unit. To address these issues, this invention provides a displacement-type piezoelectric energy harvesting device for railways and its usage method, specifically including: like Figure 1 and Figure 2 The figures provided are a 3D structural schematic diagram and an exploded structural schematic diagram of the displacement-type piezoelectric energy harvesting device in the embodiments of the present invention, with reference to... Figure 1 and Figure 2 The displacement-type piezoelectric energy harvesting device includes: an upper support plate 1, a lower support plate 6, a single-headed hexagonal column 2, a flange nut 3, a threaded base 4, a force transmission rod 5, a cymbal-type force amplification frame 7, a piezoelectric stack 8, a limiting washer 9, a fixing screw 10, an internal hexagonal screw 11, and a fixing nut 12.

[0025] It should be noted that the assembly of the height-adjustable load-bearing structure is as follows: First, pass the four threaded bases 4 through the preset positions at the bottom of the housing, ensuring that the threaded bases 4 are firmly connected to the housing. Screw the lower end of the single-headed hexagonal column 2 into the threaded base 4. Adjust the screwing depth of the single-headed hexagonal column 2 according to the actual height requirements between the rails. Then, align the reserved mounting holes on the upper load-bearing plate 1 with the upper end of the single-headed hexagonal column 2, place the upper load-bearing plate 1 on the single-headed hexagonal column 2, and finally tighten the flange nut 3 to fix the upper load-bearing plate 1 at the set height, thus completing the assembly of the height-adjustable load-bearing structure.

[0026] Reference Figure 4 and Figure 5Assembly of the energy conversion structure: Take a cymbal-type force amplification frame 7, place the limiting shim 9 inside one end of the cymbal-type force amplification frame 7, then place the piezoelectric stack 8 inside the cymbal-type force amplification frame 7, with one end of the piezoelectric stack 8 in contact with the limiting shim 9. Place another limiting shim 9 at the other end of the piezoelectric stack 8. Then screw in the fixing screw 10 to initially fix the piezoelectric stack 8 and the limiting shim 9 inside the cymbal-type force amplification frame 7. Finally, screw in the fixing nut 12, which works with the fixing screw 10 to achieve double fixation and prevent the piezoelectric stack 8 from shifting during vibration. Assemble four sets of energy conversion structures according to the above method.

[0027] It should be noted that the piezoelectric stack 8 must be kept horizontal during assembly to maximize power generation.

[0028] Reference Figure 6 In this embodiment, the piezoelectric stack 8 is formed by alternating layers of piezoelectric layers, electrode layers, and protective layers. The piezoelectric layers are made of piezoelectric ceramic sheets, with a single layer thickness of 3 mm, a cross-sectional area of ​​8 mm × 8 mm, and 20 layers in total. The electrode layers are made of copper electrode sheets, with a single layer thickness of 0.1 mm, a cross-sectional area of ​​8 mm × 8 mm, and 21 layers in total. The protective layer is made of ordinary ceramic sheets, with a single layer thickness of 3 mm, a cross-sectional area of ​​8 mm × 8 mm, and 2 layers in total. This parameter design significantly improves the charge output per unit stress while ensuring mechanical strength. It should be noted that the above parameters are merely illustrative and do not constitute a limitation of the present invention. Those skilled in the art can reasonably adjust the number of layers, cross-sectional shape, and dimensions of the piezoelectric stack 8 according to actual power requirements and installation space constraints.

[0029] Connection between the vibration transmission structure and the energy conversion structure: The lower end of the force transmission rod 5 is tightly connected to the pre-drilled hole in the center of the lower support plate 6 using a screw, ensuring that the force transmission rod 5 is perpendicular to the lower support plate 6. Four mounting holes are pre-drilled around the lower support plate 6. The lower ends of the four assembled energy conversion structures are fixed to the pre-drilled mounting holes in the lower support plate 6 using hexagonal screws 11, ensuring that the energy conversion structure is firmly connected to the lower support plate 6 and remains perpendicular.

[0030] Assembly of the overall device: Place the lower support plate 6, which connects the energy conversion structure and the force transmission rod 5, into the inner cavity of the shell, so that the force transmission rod 5 passes through the pre-set through hole at the top of the shell, and the force transmission rod 5 can slide freely along the axis within the through hole. Then, fix the upper ends of the four sets of energy conversion structures to the lower surface of the upper support plate 1 respectively through the internal hexagonal screws 11. During the connection process, it is necessary to ensure that the force on each set of energy conversion structures is uniform and to avoid tilting.

[0031] The working principle of this invention: When a train passes over a track, the longitudinal displacement of a typical railway rail due to vibration is approximately 3mm. To address this characteristic, the vibration operating range of this invention is 5mm, which fully covers the vibration amplitude range of the actual rail while retaining sufficient design redundancy. Within this range, the vibration energy generated by the rails is transmitted to the force transmission rod 5, which repeatedly moves linearly along the axial direction, causing the lower bearing plate 6 to move synchronously. Since the upper bearing plate 1 is fixed by a height-adjustable load-bearing structure, the movement of the lower bearing plate 6 causes the energy conversion structure to repeatedly stretch and reset along the axial direction. The piezoelectric stack 8 deforms during stretching and resetting, converting mechanical energy into electrical energy using the piezoelectric effect. This electrical energy is then output to the wireless sensor via parallel wires, providing a continuous and stable power supply. Simultaneously, by adjusting the single-headed hexagonal column 2 and the flange nut 3, the height of the device can be flexibly adjusted to meet the installation requirements of different rail distances, improving the versatility and practicality of the device.

[0032] Reference Figure 7 In this embodiment, the piezoelectric stacks 8 in the four energy conversion structures are connected in parallel by wires. The positive and negative wires after parallel connection are led out from the side wall of the piezoelectric stack 8 for connection to the power supply module of the wireless sensor. This parallel connection method allows the output current to be superimposed, providing higher instantaneous power under the same vibration conditions.

[0033] Alternatively, in another embodiment, if the load has high voltage requirements, multiple piezoelectric stacks 8 can be connected in series; or a combination of series connection followed by parallel connection can be used to achieve a synergistic increase in voltage and current.

[0034] Reference Figure 8 and Figure 9 The typical installation method provided in this embodiment is as follows: First, according to the clearance between the rails of the track to be installed, adjust the depth of the single-head hexagonal column 2 screwed into the threaded base 4, and lock the upper bearing plate 1 at the set height through the flange nut 3; The assembled energy harvesting device is placed into the rail space, so that the top of the force transmission rod 5 naturally contacts the lower surface of the rail. Reliable fixation can be achieved through mechanical contact and the weight of the device itself, and the force transmission rod 5 always maintains contact with the rail. When multiple energy harvesting devices are used in combination, it is recommended that they be installed at equal intervals between adjacent sleepers. Each energy harvesting device independently collects vibration energy, and the electrical energy is rectified independently and then connected in parallel to the DC bus to provide a stable power supply for multiple sets of wireless sensors distributed along the line.

[0035] This installation method requires no permanent fasteners, does not damage the track structure, and can be completed by a single person or with a single tool.

[0036] In summary, the railway track displacement piezoelectric energy harvesting device provided in this embodiment achieves efficient and stable capture and reliable electrical energy conversion of vibration energy in complex railway environments. Its core innovations are reflected in three significant technological advancements: low-interference flexible adaptation capability to the track system, high-efficiency electromechanical conversion efficiency based on force amplification mechanism, and ease of long-term maintenance and upgrades.

[0037] It should be noted that, in terms of track adaptation, the device adopts an overall low-rigidity design and a height-adjustable support structure. Through the threaded base 4, single-headed hexagonal column 2, and flange nut 3, a height-adjustable support is formed, enabling precise adjustment of the installation height according to the track height. This design not only allows the device to flexibly adapt to differences in track spacing on different lines, but its low rigidity also effectively avoids interference with the dynamic characteristics of the rail itself caused by traditional rigid installations, ensuring the safety and stability of train operation.

[0038] In terms of energy conversion, a working mechanism combining a cymbal-type force amplification frame 7 and a tension-bending structure is adopted. The cymbal-type structure efficiently amplifies the vertical force generated by the vertical deformation of the rail and converts it into radial axial pressure on the internal piezoelectric stack 8, significantly improving the conversion efficiency of mechanical energy to electrical energy and the output power of a single vibration. At the same time, the tension-bending working mode ensures that the piezoelectric stack 8 is always subjected to compressive stress, effectively avoiding the brittle fracture problem that easily occurs in piezoelectric ceramics under long-term cyclic tensile stress. Combined with multiple symmetrically arranged independent conversion units, the structural stability and service durability of the device under long-term high-frequency vibration conditions are greatly improved.

[0039] In practical engineering applications, the device adopts a detachable design. The piezoelectric power generation units, load-bearing support structures, and force transmission structures can be independently replaced, and all major functional modules support rapid on-site disassembly and replacement. This design significantly reduces the difficulty of installation and commissioning, maintenance costs, and the complexity of subsequent component upgrades. Simultaneously, the parallel design of multiple power generation units provides output power aggregation, ensuring the continuity and reliability of the wireless sensor. The entire system achieves efficient energy capture, stable power output, and convenient maintenance and management.

[0040] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the scope of protection of the present invention.

Claims

1. A railway track displacement type piezoelectric energy harvesting device, characterized in that, include: case; A height-adjustable load-bearing structure used to support piezoelectric energy harvesting devices and adapt to the installation height between rails. Vibration force transmission structure used to receive and transmit the vibration displacement of rails; An energy conversion structure connecting a height-adjustable load-bearing structure and a vibration transmission structure, which is used to convert vibration mechanical energy into electrical energy; Both the vibration transmission structure and the energy conversion structure are located inside the shell; one end of the height-adjustable load-bearing structure extends to the outside of the shell.

2. The railway track displacement type piezoelectric energy harvesting device according to claim 1, characterized in that, The height-adjustable load-bearing structure includes an upper load-bearing plate (1) and a height-adjustable support for adjusting the vertical height of the upper load-bearing plate (1).

3. The railway track displacement type piezoelectric energy harvesting device according to claim 2, characterized in that, The height-adjustable support includes multiple threaded bases (4) and a single-headed hexagonal post (2) threadedly connected to any one of the threaded bases (4), and any one of the single-headed hexagonal posts (2) can be inserted into the interior of the upper bearing plate (1); the height-adjustable support also includes a flange nut (3) that cooperates with the single-headed hexagonal post (2) to lock and fix the upper bearing plate (1).

4. The railway track displacement type piezoelectric energy harvesting device according to claim 1, characterized in that, The vibration transmission structure includes a force transmission rod (5) and a lower bearing plate (6) connected to the force transmission rod (5) by a spiral. The force transmission rod (5) is used to contact the rail and drive the lower bearing plate (6) to reciprocate.

5. The railway track displacement type piezoelectric energy harvesting device according to claim 4, characterized in that, The top of the upper support plate (1) has a through hole, and the force transmission rod (5) passes through the through hole and can move within the through hole.

6. The railway track displacement type piezoelectric energy harvesting device according to claim 1, characterized in that, The energy conversion structure includes a cymbal force amplification frame (7) and a piezoelectric stack (8) disposed inside the cymbal force amplification frame (7).

7. The railway track displacement type piezoelectric energy harvesting device according to claim 6, characterized in that, The energy conversion structure includes a cymbal force amplification frame (7) and a piezoelectric stack (8) disposed inside the cymbal force amplification frame (7).

8. The railway track displacement type piezoelectric energy harvesting device according to claim 7, characterized in that, The energy conversion structure also includes a limiting pad (9) disposed inside the cymbal force amplification frame (7) and a fixing screw (10) that fixes the piezoelectric stack (8) and the limiting pad (9) inside the cymbal force amplification frame (7).

9. The railway track displacement type piezoelectric energy harvesting device according to claim 8, characterized in that, The energy conversion structure is provided in multiple sets, and the multiple sets of energy conversion structures are symmetrically arranged between the upper bearing plate (1) and the lower bearing plate (6).

10. A method of using a railway track-displacement type piezoelectric energy harvesting device, comprising the railway track-displacement type piezoelectric energy harvesting device as described in any one of claims 1-9, characterized in that, Includes the following steps: The height can be adjusted to adjust the load-bearing structure, so that the height of the device can be adapted to the distance between the rails; The device is installed between railway rails so that the vibration transmission structure comes into contact with the rails; When a train passes by, the vibration of the rails is transmitted to the energy conversion structure through the vibration transmission structure. Energy conversion structures convert mechanical energy into electrical energy and output it to power electrical equipment.

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