A friction piezoelectric hybrid energy harvester for axle vibration signal acquisition system power supply

Abstract

The application provides a friction piezoelectric hybrid energy harvester for axle vibration signal acquisition system power supply, which comprises a ring chain, an energy acquisition module, a flexible sensing module, a voltage reduction circuit and a wireless communication unit; the ring chain is tightly covered on the outer periphery of the axle and rotates synchronously with the axle, the energy acquisition module, the voltage reduction circuit and the wireless communication unit are fixed on the ring chain, and the flexible sensing module is attached to the surface of the axle. The energy acquisition module adopts a V-shaped shell and a magnetic repulsion type bistable swing piece, integrates piezoelectric power generation and friction power generation to realize hybrid energy harvesting, and converts the mechanical energy of the axle rotation into electrical energy; the flexible sensing module realizes real-time acquisition of the strain state signal of the axle based on the piezoresistance effect, the electrical energy is used to supply power to the sensing and wireless communication unit after voltage reduction management, and wireless transmission of the monitoring signal is realized. The application can be directly installed on the surface of the axle, integrates self-powered, state sensing and wireless communication functions, and is suitable for real-time online health monitoring of the axle of trains, engineering machinery and other equipment.

Description

Technical Field

[0001] This invention relates to the field of rotational energy generation technology, and more specifically, to a triboelectric hybrid energy harvester for powering a vehicle axle vibration signal acquisition system. Background Technology

[0002] Rotating shafts are widely used in machinery manufacturing and industrial equipment, transportation, and energy and power industries because they can smoothly and quickly transmit the rotational power and torque output from the prime mover to the driven parts. For example, train axles transmit the engine's power to the wheels. During continuous operation, train axles experience bending and torsional deformation, fatigue cracks, corrosion damage, overload damage, and impacts from foreign objects. Currently, damage trends are mainly analyzed and predicted by monitoring signals from the axle itself. However, the rotation of the axle generates strong centrifugal force. If the wireless health monitoring system or its components are fixed to the axle, they can easily detach, causing the monitoring system to malfunction or even leading to serious accidents. Furthermore, the power supply and signal transmission of the wireless health monitoring system are also problems that urgently need to be solved.

[0003] Currently, the traditional method for powering wireless health monitoring systems is primarily battery power. However, this method suffers from limitations such as energy density, lifespan and performance degradation, cost, and resource constraints. Environmental energy harvesting has attracted widespread attention due to its advantages of being maintenance-free, flexible in design and deployment, highly scalable, and low-cost. Harvesting environmental energy and using it to power wireless health monitoring systems is a worthwhile approach. Researchers have proposed a tetrastable piezoelectric energy harvester with a time-varying potential well that can be mounted on a rotating shaft. When the shaft speed is below 120 rpm, this energy harvester has a wider operating frequency range and a greater system response than bistable and tristable harvesters. However, this energy harvester can only be installed at the shaft cross-section, not on the shaft surface, severely limiting its application. Therefore, there is an urgent need for an energy harvester that can be fixed to the shaft surface and has high harvesting efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a triboelectric hybrid energy harvester for powering a vehicle axle vibration signal acquisition system, which addresses the shortcomings of existing technologies and solves the problems mentioned in the background.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A triboelectric hybrid energy harvester for powering a vehicle axle vibration signal acquisition system is installed on the axle and includes a ring chain, an energy harvesting module, a step-down circuit and a wireless communication unit, and a flexible sensing module.

[0006] A ring chain surrounds the outer circumference of the rotating shaft and moves synchronously with the shaft's rotation. An energy harvesting module is mounted on the ring chain and moves synchronously with it, converting mechanical energy into electrical energy.

[0007] The step-down circuit and the wireless communication unit are fixed on the ring chain and electrically connected to the energy harvesting module. The circuit is used to receive the electrical energy generated by the energy harvesting module and wirelessly transmit the monitoring signal.

[0008] The flexible sensing module is attached to the surface of the rotating shaft to sense the physical state signals of the rotating shaft.

[0009] Furthermore, the energy harvesting module includes a first housing, a second housing, a swing element, and a power generation unit.

[0010] The first outer shell is fixedly mounted on the ring chain, and the second outer shell is located inside the first outer shell, with the bottom of the second outer shell connected to the bottom of the first outer shell.

[0011] The swinging component is located inside the second housing, and the bottom of the swinging component extends to the outside of the second housing and connects to the bottom of the first housing. The swinging component swings when the ring chain moves.

[0012] The power generation unit is installed on the swinging component and is used to generate electrical energy by the swinging of the corresponding swinging component.

[0013] Furthermore, the power generation unit includes piezoelectric ceramic sheets attached to both sides of the oscillating member to generate electrical energy when the oscillating member oscillates and deforms.

[0014] Preferably, the power generation unit further includes a triboelectric power generation unit, which includes a first friction layer disposed on the swing member and a second friction layer disposed on the inner sidewall of the second housing. The first friction layer and the second friction layer periodically contact and separate during the swinging process of the swing member to generate electrical energy.

[0015] Furthermore, the swinging component includes a thin plate, a fixed magnet, and a moving magnet. The fixed magnet is mounted on the top of the first housing, and the moving magnet is mounted on the thin plate. The moving magnet and the fixed magnet repel each other.

[0016] Furthermore, the second outer shell has a V-shaped structure, and a rotating rod is provided at the bottom of the second outer shell. The rotating rod is rotatably connected to the second outer shell through a bearing, and the rotating rod is connected to the first outer shell.

[0017] Furthermore, the flexible sensing module includes a flexible substrate layer, a sensitive layer, and an encapsulation layer that are sequentially bonded together. The surface of the sensitive layer is provided with a single conductive heterocyclic ring, which is led out through an electrode.

[0018] Furthermore, the step-down circuit and wireless communication unit include a perforated cover plate, a wireless Bluetooth unit, an I-shaped housing, and a step-down circuit module. The I-shaped housing has a receiving cavity for accommodating the step-down circuit module and the wireless Bluetooth unit. The perforated cover plate is detachably connected to the I-shaped housing, and the perforated cover plate has clearance holes for installing the wireless Bluetooth unit.

[0019] Furthermore, the ring chain includes an L-shaped mounting plate, a pin, and chain links. Multiple chain links are connected end to end by the pin to form a ring structure. Multiple L-shaped mounting plates are arranged in a ring and divided into two groups, which are fixedly connected to the end of the pin away from the chain link.

[0020] In one implementation, the material of the monomeric conductive heterocyclic ring is poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid.

[0021] The present invention has at least the following advantages or beneficial effects: This invention, through the design of a ring chain covering and rotating synchronously with the axle, enables the entire energy harvester to be stably installed on the cylindrical outer surface of the axle, breaking through the limitation of existing technologies where energy harvesters can only be installed on the end face of the rotating shaft.

[0022] When the axle rotates, the ring chain drives the energy harvesting module on it to move synchronously. The oscillating component within the energy harvesting module oscillates under the influence of gravity or magnetism, thereby driving the power generation unit to convert mechanical energy into electrical energy. The generated electricity powers a step-down circuit and a wireless communication unit, both fixed to the chain, enabling the unit to receive and wirelessly transmit signals from the flexible sensing module. The flexible sensing module, attached to the axle surface, can sensitively sense changes in the axle's physical state, such as strain, and transmit the signals to the wireless communication unit. Thus, this invention integrates energy harvesting, signal sensing, power management, and wireless communication functions into a compact system that can be deployed on the axle surface. It enables autonomous, real-time, online monitoring of the axle's status without external power supply, greatly improving the system's deployment flexibility and application potential.

[0023] In addition, the energy harvesting module combines piezoelectric and triboelectric mechanisms and utilizes magnetic repulsion to achieve bistable operation, which can adapt to vibration excitation over a wider frequency band, improving the efficiency and robustness of energy harvesting. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A schematic diagram of a triboelectric hybrid energy harvester for powering an axle vibration signal acquisition system provided by the present invention; Figure 2 A schematic diagram of the energy harvesting module provided by the present invention; Figure 3 A schematic diagram of the structure of the flexible sensing module provided by the present invention; Figure 4 This is a schematic diagram of the step-down circuit and wireless communication unit provided by the present invention; Figure 5 This is a schematic diagram of the structure of the ring chain provided by the present invention; Figure 6 This is a schematic diagram of an exemplary system architecture for the application of the present invention to train axles.

[0026] Icons: 1. Shaft support module; 2. Flexible sensing module; 20. Electrode; 21. Flexible substrate layer; 22. Monolithic conductive heterocyclic ring; 23. Encapsulation layer; 24. Sensing layer; 3. Energy harvesting module; 30. Second outer shell; 31. Second friction layer; 32. Bearing; 33. Rotating rod; 34. First friction layer; 35. Piezoelectric ceramic sheet; 36. Thin plate; 37. Second bracket; 38. Fixed magnet; 39. First outer shell; 40. First bracket; 41. Moving magnet; 5. Step-down circuit and wireless communication unit; 50. Hollowed-out cover plate; 51. Wireless Bluetooth unit; 52. I-shaped outer shell; 53. Step-down circuit module; 11. Axle; 13. Ring chain; 131. L-shaped mounting plate; 132. Pin; 133. Chain link. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0028] In vehicles such as trains and large construction machinery, as well as heavy equipment, axles operate under continuous high-speed rotation and high loads, which can easily lead to physical changes such as bending deformation, vibration, and fatigue cracks. Real-time monitoring of these conditions is crucial for preventing safety accidents. However, the power supply and stable signal transmission of wireless monitoring systems deployed on axles have always been technical challenges. This invention provides a self-powered triboelectric piezoelectric hybrid energy harvester that can be directly mounted on the axle surface, providing power to the wireless sensing system and enabling wireless transmission of monitoring signals.

[0029] Figure 1This illustration shows the overall structure of a triboelectric hybrid energy harvester for powering an axle vibration signal acquisition system, as provided in an embodiment of the present invention. Figures 1 to 6 As shown, in the axle support module 1, a pair of right and left wheels of the running gear are symmetrically pressed into both sides of the axle 11 via an interference fit. The triboelectric hybrid energy harvester is mounted on the axle 11, preferably at the axial center of the axle 11, to ensure uniform force distribution at both ends of the axle 11 when rotating at different speeds. It includes a ring chain 13, an energy harvesting module 3, a voltage reduction circuit and wireless communication unit 5, and a flexible sensing module 2. The ring chain 13 tightly wraps around the outer circumference of the axle 11 and can move synchronously with the rotation of the axle 11, thus stably and reliably fixing the entire energy harvester to the cylindrical outer surface of the axle. The energy harvesting module 3 is fixedly mounted on the ring chain 13, and therefore can rotate synchronously with the axle, converting mechanical energy into electrical energy using vibration or relative motion during rotation. The flexible sensing module 2 is directly attached to the surface of the axle 11 by bonding or other means, and is used to sense the physical state signals such as strain and deformation of the axle during operation in real time. The step-down circuit and the wireless communication unit 5 are also fixed on the ring chain 13 and electrically connected to the energy harvesting module 3. The ring chain 13 receives and manages the electrical energy generated by the energy harvesting module 3, and simultaneously processes and wirelessly transmits monitoring signals from the flexible sensing module 2. The core of this invention lies in achieving stable deployment of the entire system on the rotating axle surface through the ring chain 13, and solving the power supply problem of the wireless monitoring system through the self-generated power of the energy harvesting module 3. This integrates energy harvesting, signal sensing, power management, and wireless communication, enabling autonomous, real-time online monitoring of the axle's operating status.

[0030] For details, please refer to Figure 1 and Figure 5 The annular chain 13 includes L-shaped mounting plates 131, pins 132, and chain links 133. Multiple chain links 133 are sequentially linked end-to-end via pins 132, forming a closed-loop annular structure. Multiple L-shaped mounting plates 131 are arranged in a ring, divided into two groups. One side of each group of L-shaped mounting plates 131 is fixedly connected to the two ends of the pins 132 furthest from the chain links 133. The other side of the L-shaped mounting plates 131 is used to mount the energy harvesting module 3 and the step-down circuit and wireless communication unit 5. This structural design allows the chain to tightly wrap around axles of different diameters, and the L-shaped mounting plates 131 provide a stable mounting platform for other modules. The annular chain 13 is typically made of high-strength alloy steel or similar materials to withstand the centrifugal force generated by high-speed rotation. In practical applications, two sets of energy harvester units can be installed symmetrically along the axial direction of the axle 11 to better balance the centrifugal force and ensure the smooth operation of the system.

[0031] In this embodiment, the energy harvesting module 3 is the core component for converting mechanical energy into electrical energy. Figure 2A specific structure of the energy harvesting module 3 is shown in detail. The energy harvesting module 3 includes a first housing 39, a second housing 30, a swinging member, and a power generation unit. The first housing 39 is fixedly mounted on the L-shaped mounting plate 131 of the annular chain 13 by bolts or other fasteners. The second housing 30 is located in the internal cavity of the first housing 39. In this embodiment, the second housing 30 has a V-shaped structure. The bottom of the second housing 30 is connected to the bottom of the first housing 39 by a rotating rod 33. Specifically, the rotating rod 33 is rotatably connected to a through hole at the bottom of the second housing 30 through a bearing 32, allowing the second housing 30 to swing slightly relative to the first housing 39 about the axis of the rotating rod 33. The swinging member is located within the internal space of the second housing 30, and the bottom of the swinging member extends out of the second housing 30 and is bolted to a mounting seat at the bottom of the first housing 39. When the axle 11 drives the entire energy harvester to rotate, the swinging member will swing relative to the second housing 30 due to the periodic change in the direction of gravity and possible vibration excitation.

[0032] The oscillating component includes a thin plate 36, a moving magnet 41, and a fixed magnet 38. The thin plate 36 can be a cantilever beam structure, with its root connected to the bottom of the first housing 39 and its free end extending into or out of the second housing 30. The moving magnet 41 is mounted on the top of the free end of the thin plate 36 via a first bracket 40. The fixed magnet 38 is mounted on the top outer side of the first housing 39 via a second bracket 37. The magnetic poles of the moving magnet 41 and the fixed magnet 38 are arranged opposite each other, generating a repulsive force. This magnetic repulsion, combined with gravity, provides a nonlinear restoring force for the oscillating component, forming a bistable or more complex dynamic system. This effectively broadens the operating frequency band of the energy harvesting module 3, enabling it to efficiently excite oscillation over a wider range of axle speeds.

[0033] A power generation unit is mounted on the oscillating component to generate electrical energy in response to its oscillation. The power generation unit includes a piezoelectric power generation section and a triboelectric power generation section. The piezoelectric power generation section includes piezoelectric ceramic sheets 35, which are attached to the lower sides of both sides of the thin plate 36 in the oscillating component. When the thin plate 36 bends due to oscillation, the piezoelectric ceramic sheets 35 attached to the thin plate 36 undergo tensile or compressive strain, generating an alternating voltage based on the piezoelectric effect. The triboelectric power generation section is a triboelectric power generation unit, which includes a first friction layer 34 disposed on the oscillating component and a second friction layer 31 disposed on the inner wall of the second outer shell 30. The first friction layer 34 is a copper film, attached to both sides of the upper part of the thin plate 36; the second friction layer 31 is a fluorinated ethylene propylene copolymer film, attached to the inner walls of both sides of the V-shaped second outer shell 30. When the thin plate 36 oscillates, the first friction layer 34 and the second friction layer 31 periodically contact and separate, generating an alternating current based on contact electrification and electrostatic induction effects. The combination of piezoelectric and triboelectric power generation enables the energy harvesting module 3 to operate effectively under excitation at different frequencies and amplitudes, improving overall energy harvesting efficiency and robustness. The V-shaped structure of the second outer shell 30, with its inclined inner wall design, helps to guide and increase the contact area and contact force between the friction layers, thereby improving the output of triboelectric power generation.

[0034] Please refer to this again. Figure 1 As shown, the flexible sensing module 2 is attached to the surface of the axle 11 to sense the physical state signals of the axle. Figure 3 As shown, the flexible sensing module 2 includes a flexible substrate layer 21, a sensitive layer 24, and an encapsulation layer 23 sequentially bonded together. The flexible substrate layer 21 and the encapsulation layer 23 are typically made of materials with excellent elasticity and adhesion, such as polydimethylsiloxane. These materials can both firmly encapsulate and protect the sensitive layer 24 and allow it to fit tightly and follow the minute deformations of the axle surface. Monomeric conductive heterocyclic rings 22 are disposed on the surface of the sensitive layer 24, and these rings are led out through electrodes 20 to connect to the signal processing circuit. The preferred material for the monomeric conductive heterocyclic rings 22 is poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, a conductive polymer composite material with high electrical conductivity. Its working principle is based on the piezoresistive effect: when the axle bends or vibrates, generating strain, the strain is transmitted to the sensitive layer 24 almost without loss through the flexible substrate layer 21 and the encapsulation layer 23, causing microstructural deformation of the embedded monomeric conductive heterocyclic rings 22, thereby changing their resistance value. By measuring the change in resistance, the strain state of the axle can be deduced, and the risk of damage such as crack initiation or overload can be assessed.

[0035] In this embodiment, the step-down circuit and the wireless communication unit 5 are responsible for power processing and signal transmission. For example... Figure 4As shown, the step-down circuit and wireless communication unit 5 include a perforated cover plate 50, a wireless Bluetooth unit 51, an I-shaped housing 52, and a step-down circuit module 53. The I-shaped housing 52 is fixed to the L-shaped mounting plate 131 of the ring chain 13 through mounting holes on its base. The I-shaped housing 52 has a cavity for accommodating the step-down circuit module 53 and the wireless Bluetooth unit 51. The perforated cover plate 50 and the I-shaped housing 52 are detachably connected by clips or screws, facilitating the installation and maintenance of internal components. The perforated cover plate 50 has clearance holes for installing and exposing the antenna or interface of the wireless Bluetooth unit 51. The step-down circuit module 53 is connected to the output terminal of the energy harvesting module 3 through wires. It contains circuits such as a rectifier bridge, filter capacitor, voltage regulator chip, and DC-DC step-down converter, which are used to rectify, filter, and step down the AC power generated by the energy harvesting module to the stable DC voltage required by the working circuits of the wireless Bluetooth unit 51 and other components. The wireless Bluetooth unit 51 is connected to the output of the step-down circuit module 53 and the signal output of the flexible sensing module 2. It integrates a microcontroller, an analog-to-digital converter, and a Bluetooth RF module. The microcontroller is responsible for acquiring and processing the analog signals (usually resistance or voltage changes) transmitted from the flexible sensing module 2, and then wirelessly transmitting the processed digital signals to the vehicle-mounted host or ground monitoring station via the Bluetooth RF module, thereby achieving remote, real-time monitoring of the axle status. The selection and connection methods of circuit components such as the wireless Bluetooth unit 51 and the step-down circuit module 53 are common knowledge to those skilled in the art and will not be elaborated upon here.

[0036] In summary, this invention stabilizes the energy harvesting system onto the surface of a rotating axle using a ring chain. Synchronous rotation excites multi-steady-state vibrations in the built-in oscillating component, and combined with piezoelectric and triboelectric generator mechanisms, mechanical energy is efficiently harvested. The generated energy, after management, powers an integrated wireless sensing and communication unit, driving a flexible sensing module attached to the axle to operate and transmit monitoring signals back. This constitutes a self-powered, wireless online axle health status monitoring solution. This design ingeniously solves the challenges of powering and installing monitoring equipment on rotating components, and has high engineering application value.

[0037] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A triboelectric hybrid energy harvester for powering a vehicle axle vibration signal acquisition system, mounted on a vehicle axle, characterized in that, include: A ring chain covers the outer circumference of the rotating shaft and moves synchronously with the rotation of the shaft; An energy harvesting module is installed on a ring chain. The energy harvesting module moves synchronously with the ring chain, converting mechanical energy into electrical energy. The step-down circuit and wireless communication unit are fixed on the ring chain and electrically connected to the energy harvesting module. They are used to receive the electrical energy generated by the energy harvesting module and wirelessly transmit the monitoring signal. The flexible sensing module is attached to the surface of the rotating shaft to sense the physical state signals of the shaft.

2. The triboelectric hybrid energy harvester for powering an axle vibration signal acquisition system according to claim 1, characterized in that, The energy harvesting module includes a first housing, a second housing, a swing element, and a power generation unit; The first outer shell is fixedly mounted on the ring chain, and the second outer shell is located inside the first outer shell, with the bottom of the second outer shell connected to the bottom of the first outer shell; The swinging component is located inside the second housing, and the bottom of the swinging component extends to the outside of the second housing and connects to the bottom of the first housing. The swinging component swings when the ring chain moves. The power generation unit is installed on the swinging component and is used to generate electrical energy by the swinging of the corresponding swinging component.

3. The triboelectric hybrid energy harvester for powering an axle vibration signal acquisition system according to claim 2, characterized in that, The power generation unit includes piezoelectric ceramic sheets that are attached to both sides of the oscillating component to generate electrical energy when the oscillating component oscillates and deforms.

4. A triboelectric hybrid energy harvester for powering an axle vibration signal acquisition system according to claim 2, characterized in that, The power generation unit also includes a triboelectric power generation unit, which includes a first friction layer disposed on the swinging member and a second friction layer disposed on the inner sidewall of the second housing. The first friction layer and the second friction layer periodically contact and separate during the swinging process of the swinging member to generate electrical energy.

5. A triboelectric hybrid energy harvester for powering an axle vibration signal acquisition system according to claim 2, characterized in that, The swinging component includes a thin plate, a fixed magnet, and a moving magnet. The fixed magnet is mounted on the top of the first housing, and the moving magnet is mounted on the thin plate. The moving magnet and the fixed magnet repel each other.

6. A triboelectric hybrid energy harvester for powering an axle vibration signal acquisition system according to claim 2, characterized in that, The second outer shell has a V-shaped structure, and a rotating rod is provided at the bottom of the second outer shell. The rotating rod is rotatably connected to the second outer shell through a bearing, and the rotating rod is connected to the first outer shell.

7. A triboelectric hybrid energy harvester for powering an axle vibration signal acquisition system according to claim 1, characterized in that, The flexible sensing module includes a flexible substrate layer, a sensitive layer, and an encapsulation layer that are sequentially bonded together. The surface of the sensitive layer is provided with a monomeric conductive heterocyclic ring, which is led out through an electrode.

8. A triboelectric hybrid energy harvester for powering an axle vibration signal acquisition system according to claim 1, characterized in that, The step-down circuit and wireless communication unit includes a perforated cover plate, a wireless Bluetooth unit, an I-shaped housing, and a step-down circuit module. The I-shaped housing has a cavity for accommodating the step-down circuit module and the wireless Bluetooth unit. The perforated cover plate is detachably connected to the I-shaped housing, and the perforated cover plate has clearance holes for installing the wireless Bluetooth unit.

9. A triboelectric hybrid energy harvester for powering an axle vibration signal acquisition system according to claim 1, characterized in that, The ring chain includes an L-shaped mounting plate, a pin, and chain links. Multiple chain links are connected in sequence by the pin to form a ring structure. Multiple L-shaped mounting plates are arranged in a ring and divided into two groups, which are fixedly connected to the end of the pin away from the chain link.

10. A triboelectric hybrid energy harvester for powering an axle vibration signal acquisition system according to claim 7, characterized in that, The material of the monomer conductive heterocyclic ring is poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid.

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