A contact-separation triboelectric power generation device, method and application based on a rotating shaft

Abstract

This invention discloses a contact-separation triboelectric power generation device, method, and application based on a rotating shaft, belonging to the field of air-fluid power generation technology. This invention solves the problem of poor compatibility between the energy harvesting structure and rotational motion in current energy harvesting methods that install energy harvesters on rotating shafts and collect nearby air-fluid. The invention includes: a rotating shaft connection mechanism for connecting to the circumferential surface of the rotating shaft; a contact-separation triboelectric power generation mechanism for collecting air-fluid energy during shaft rotation and converting the collected air-fluid energy into electrical energy; and a support frame with at least one arc-shaped through-slot, within which are arranged a first fixed power generation component, a second fixed power generation component, and a movable power generation component, the movable component being movable along the axial direction of the rotating shaft within the arc-shaped through-slot. This invention features a simple configuration, good economy, and high fluid energy conversion efficiency, making it suitable for low-velocity or turbulent environments, such as confined spaces like train bogie shafts.

Description

Technical Field

[0001] This invention belongs to the field of air fluid power generation technology, specifically relating to a contact separation triboelectric power generation device, method, and application based on a rotating shaft. Background Technology

[0002] Axles are almost ubiquitous in industrial settings, especially on freight trains where numerous wheelsets and axles exist. Over long-term operation, axles can experience various failures, some of which can lead to serious train accidents. Therefore, real-time monitoring of axles using wireless health monitoring systems is necessary. These systems require numerous miniature sensors and wireless transmission modules. These sensors and modules require a stable power supply to function properly; however, wiring and layout on the axles present significant challenges. Researchers have long explored suitable advanced power systems. Harvesting the kinetic energy of moving airflow near the outer edge of the axle to drive a generator and power low-power components is considered a novel approach. However, designing a novel and reliable energy harvesting system on the outer edge of the axle presents a significant challenge.

[0003] Triboelectric nanogenerators (TENGs) have long attracted researchers' attention due to their advantages such as low cost, high energy conversion efficiency, sustainability, small size, compact dimensions, versatility, and stability. The vertical contact separation mode in triboelectric energy harvesting devices offers advantages such as easy harvesting of impact energy, high voltage, simple structure, easy packaging, and high-efficiency harvesting of low-frequency kinetic energy. However, mounting the energy harvester on a rotating shaft and collecting nearby airflow presents challenges such as compatibility issues between the energy harvesting structure and rotational motion, interface difficulties for energy management and wireless transmission, difficulties in environmental adaptability and packaging protection, complex multi-field coupling dynamics, and interference from installation space and structure. Furthermore, existing energy harvesters for harvesting rotational energy are mainly mounted on the end face of the shaft, making it impossible to mount them on the shaft surface. This results in the need to design new slip rings and add numerous wiring harnesses for longer axles, further increasing costs. Summary of the Invention

[0004] To address the problem of poor compatibility between the energy harvesting structure and rotational motion in existing technologies where the energy harvester is mounted on a rotating shaft and collects air fluid nearby, this invention provides a contact-separated triboelectric power generation device, method, and application based on a rotating shaft.

[0005] The technical solution adopted in this invention is as follows:

[0006] A contact-separation triboelectric power generation device based on a rotating shaft, comprising:

[0007] A rotating shaft connection mechanism is used to connect to the circumferential surface of a rotating shaft;

[0008] A contact-separation triboelectric generator mechanism is used to collect air fluid energy during the rotation of a rotating shaft and convert the collected air fluid energy into electrical energy. It includes a support frame connected to a rotating shaft connection mechanism. At least one arc-shaped through-slot is provided within the support frame, extending circumferentially along the rotating shaft, through which air fluid can pass. A first contact-separation triboelectric generator unit and a second contact-separation triboelectric generator unit are disposed within the arc-shaped through-slot. Each unit includes a first fixed generator component and a second fixed generator component fixedly connected to the arc-shaped through-slot. The first and second units also include a shared movable generator component positioned between the two fixed generator components. This movable generator component can move axially along the rotating shaft within the arc-shaped through-slot. The first and second units are electrically connected to an external circuit to form a closed loop.

[0009] With this technical solution, when the shaft rotates at a certain speed, the support frame begins to rotate along the train axle's rotation center. Simultaneously, the movable generator in its arc-shaped slot and the first fixed generator begin to enter the initial contact stage. Due to the different spatial arrangements of the movable and fixed generators in the electrostatic potential sequence, charge transfer occurs between them. The first fixed generator, with its high Pauling scale value, can capture electrons from the strongly cationic surface of the movable generator. Therefore, in the interface contact area, the first fixed generator gains excess electrons and becomes electronegative, while the surface of the movable generator loses electrons and carries an equal amount of positive charge. At this point, because the electrodes of the movable and fixed generators are kept in a direct-connected or load-connected state through an external circuit, the entire system is in an electrically neutral state. When the constant-velocity fluid is disturbed, the movable generator and the first fixed generator enter the separation stage. Since the interface charge is static, it will remain on the material surface for a period of time under an ideal environment. Therefore, when the movable generator and the first fixed generator separate, a stable contact potential difference will be formed between the surfaces of the negatively charged first fixed generator and the positively charged movable generator. To balance the potential difference, using the electrostatic induction effect, the unbound electrons in the movable generator will be repelled by the negative electrostatic charge of the first fixed generator, while the electrons in the first fixed generator will be attracted. Therefore, electrons will flow from the movable generator to the first fixed generator through the external load circuit, thus forming a transient current. When the movable generator and the first fixed generator enter the complete separation stage, the electric field balance between them will be temporarily established, and the conduction current in the external load circuit will no longer flow. In this case, the movable generator becomes positively charged due to the electrons being transferred out, and the first fixed generator becomes negatively charged due to the electrons being received. When the active generator and the first fixed generator enter the re-contact stage, the potential gradient between them gradually decreases because the opposite polarity charges on the surfaces of the active generator and the first fixed generator attract each other. The charge density distribution formed by the induced charge effect is no longer maintained. As a result, electrons will move in the opposite direction through the external load circuit, flowing from the first fixed generator back to the active generator, forming a transient current in the opposite direction to the separation stage.

[0010] Preferably, the rotating shaft connection mechanism is a ring-shaped double-row symmetrical bent-ear chain plate, the support frame is fixedly connected to the double-row symmetrical bent-ear chain plate by bolts, and the double-row symmetrical bent-ear chain plate is interference-fitted with the circumference of the rotating shaft.

[0011] By adopting this technical solution, the versatility and ease of operation of the double-row symmetrical bent-ear type rigid chain links allow it to be applied to engineering fields such as optical axis surfaces, significantly enriching the service environment of the energy trap. Simultaneously, the double-row symmetrical bent-ear type chain links can circumferentially cover typical working conditions such as rotating shaft systems, enabling non-intrusive installation of the rotating shaft. Thanks to the rigid configuration of the chain links, this mechanism possesses excellent structural robustness and long-term stability, a reasonable topological layout, high space utilization efficiency, smooth operation, and effectively suppresses load sway.

[0012] Preferably, the support frame is a column with fan-shaped annular surfaces on both the upper and lower surfaces. The arc-shaped through groove extends from one radial side of the support frame to the other radial side. The upper and lower surfaces of the support frame face the two cross-sections of the rotating shaft, respectively. The inner arc surface of the support frame is set close to the circumference of the rotating shaft.

[0013] After adopting this technical solution, the support frame structure is simple and has significant advantages such as simple configuration, good economy and high fluid energy conversion efficiency. It can be applied to low flow velocity or turbulent environment, such as narrow scenarios such as train bogie shaft.

[0014] Preferably, both the arc-shaped through groove and the movable power generation component are cylindrical structures with fan-shaped annular surfaces on both the upper and lower surfaces, and the thickness of the arc-shaped through groove is greater than the thickness of the movable power generation component.

[0015] Preferably, the first fixed power generation component includes a front fixed copper film fixedly connected to the side wall of the arc-shaped through groove, and a front polymer film is also connected to the front fixed copper film; the second fixed power generation component includes a rear fixed copper film fixedly connected to the side wall of the arc-shaped through groove, and a rear polymer film is also connected to the rear fixed copper film; the movable power generation component is a movable copper film located between the front polymer film and the rear polymer film.

[0016] A contact-separation triboelectric power generation method based on a rotating shaft is used. The specific process is as follows: when the rotating shaft rotates, it drives the support frame to rotate through the rotating shaft connection mechanism. During the rotation, the movable power generation component moves under the excitation of air fluid and comes into contact with or separates from the first fixed power generation component or the second fixed power generation component, thereby generating current.

[0017] An application of a contact-separation triboelectric generator based on a rotating shaft is described. It is installed on a train axle to power a detection device that monitors the operating status of the train axle, while simultaneously outputting a sensing signal indicating the operating status of the train axle.

[0018] Preferably, the detection device includes a flexible sensing mechanism, which includes several strain gauges that are uniformly connected to the circumferential surface of the train wheel axle. The detection device is electrically connected to the contact-separated triboelectric generator mechanism through a single-channel full-bridge transmitter mechanism and an AC-DC converter mechanism.

[0019] Preferably, each strain gauge includes electrode leads, a passivation layer, a flexible substrate, and a response unit.

[0020] With this technical solution, when the train axle begins to rotate at a certain speed, the strain gauge is subjected to external pressure, causing a change in the cross-section of the flexible substrate. This, in turn, leads to a change in the passivation layer, ultimately causing a change in the resistance of the response unit. The magnitude of this resistance change is then measured by the wireless acquisition module in the single-channel full-bridge transmitter module and converted into a strain value at the measuring point. This value is then transmitted to the wireless transmission module of the single-channel full-bridge transmitter module.

[0021] Preferably, the AC-DC converter mechanism and the single-channel full-bridge transmitter mechanism are connected to the rotating shaft connection mechanism and / or support frame.

[0022] Preferably, the AC-DC converter structure includes a semiconductor rectifier network, a power transformer, a low-pass filter network, a storage capacitor, and an energy harvester model.

[0023] With this technical solution, the core function of the semiconductor rectifier network is to guide the polarity and periodicity of the AC signal output from the energy harvester model, thereby achieving AC-DC signal conversion. The power transformer performs basic voltage conversion and electrical isolation, ensuring the safety and compatibility of subsequent circuits. The low-pass filter network typically consists of high-capacity capacitors and inductors, suppressing the ripple of the drastically fluctuating pulsed DC signal after AC-DC conversion. Finally, the output DC signal is transmitted to the storage capacitor, where the charging and discharging effect of the capacitor further suppresses output voltage ripple, thus obtaining a sufficiently stable DC voltage that meets application requirements.

[0024] Preferably, the single-channel full-bridge transmitter mechanism includes an equipment interface cover, an RS485 half-duplex differential balanced signal transmitter, a chopper step-down circuit, and an electronic component support.

[0025] With this technical solution, the RS485 half-duplex differential balanced signal transmitter consists of a voltage divider resistor network, a voltage clamping circuit, an ADC (Analog-to-Digital Converter), a microcontroller, a MAX485 chip, a crystal oscillator, a power management circuit, and a PCB antenna. After measuring the external voltage, the RS485 half-duplex differential balanced signal transmitter transmits it to the voltage and protection circuit. The safe analog voltage, after being divided by the voltage divider resistor network, enters the ADC, which converts this safe analog voltage value into a digital value at a fixed resolution. The microcontroller reads the digital value from the ADC and calculates the original external voltage. This voltage value is formatted into a data packet containing a start bit, device ID, voltage data, and parity bit. The microcontroller then transmits the data packet to the MAX485 chip via a serial communication protocol. The MAX485 chip encapsulates the data packet and radiates it through the PCB antenna. Remote devices receive the data packet through their antenna interface. The chopper-step-down circuit mainly consists of a MOSFET, a synchronous rectifier diode, an inductor, an output capacitor, a PWM controller chip, a feedback resistor network, and an input capacitor. The electrodes of the AC-DC converter mechanism are connected to the input ports of the chopper step-down circuit and provide a stable voltage for the single-channel full-bridge transmitter module.

[0026] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0027] 1. The contact-separation triboelectric generator based on the rotating shaft provided by the present invention is a new type of flexible chain energy harvester developed based on the double-row symmetrical bent-ear type chain plate structure. By utilizing the generalization ability and ease of operation of rigid chain links, it can be applied to engineering fields such as optical axis surfaces, which significantly enriches the service environment of energy harvesters.

[0028] 2. The flexible double-row symmetrical bent-ear type chain plate of the present invention can be circumferentially covered in typical working conditions such as rotating shaft systems, and can realize non-intrusive installation of rotating shafts. Thanks to the rigid configuration of the chain links, the mechanism has both excellent structural robustness and long-term stability, reasonable topological layout, high space utilization efficiency, smooth operation, and effectively suppresses load swing.

[0029] 3. The contact separation triboelectric power generation mechanism of the present invention has significant advantages such as simple configuration, good economy and high fluid energy conversion efficiency. It can be applied to low flow velocity or turbulent environment, such as narrow scenarios such as train bogie shaft.

[0030] 4. The single-channel full-bridge transmitter module of the present invention adopts RS485 half-duplex differential balanced signal transmitter, voltage divider resistor network, voltage clamping circuit, analog-to-digital converter, microcontroller, MAX485 chip, crystal oscillator, power management circuit and PCB antenna and other modules, which can timely collect the sensing signal of the flexible sensing module and send it to the host computer, realizing the real-time acquisition, transmission and processing of sensor signals. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the contact-separation triboelectric power generation mechanism in this invention;

[0032] Figure 2 This is a schematic diagram of the structure of the contact separation triboelectric power generation device based on the rotating shaft in the present invention when applied to a train suspension system;

[0033] Figure 3 for Figure 2 A magnified view of a section at point A in the middle;

[0034] Figure 4 This is a schematic diagram showing the positional relationship between the contact-separated triboelectric power generation mechanism and the single-channel full-bridge transmitter in this invention.

[0035] Figure 5 This is a schematic diagram of the single-channel full-bridge transmitter mechanism in this invention;

[0036] Figure 6 This is a schematic diagram of the AC-DC converter mechanism in this invention;

[0037] Figure 7 This is a schematic diagram of the structure of the double-row symmetrical curved ear type chain plate in this invention;

[0038] Figure 8 This is a diagram of the debugging software interface in this invention;

[0039] Among them, 1-train bogie system, 11-train axle, 12-train wheel, 13-brake disc, 14-axle box rear cover, 15-bogie side frame, 16-intermediate connecting component, 17-axle box body, 18-axle box front cover, 2-flexible sensing mechanism, 20-electrode lead, 21-passivation layer, 22-flexible substrate, 23-response unit, 3-rotation shaft-based contact-separated triboelectric generator, 31-contact-separated triboelectric generator mechanism, 311-support frame, 312-arc-shaped passage Slot, 313-First fixed generator, 314-Modible generator, 315-Second fixed generator, 32-Shaft connection mechanism, 4-Single-channel full-bridge transmitter, 40-Equipment interface cover, 41-RS485 half-duplex differential balanced signal transmitter, 42-Chopper step-down circuit, 43-Electronic component bracket, 5-AC-DC converter mechanism, 50-Semiconductor rectifier network, 51-Power transformer, 52-Low-pass filter network, 53-Storage capacitor, 54-Energy harvester model. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0041] In the description of the embodiments of this application, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0042] like Figure 1 As shown, a shaft-based contact-separation triboelectric power generation device is characterized by comprising:

[0043] The rotating shaft connecting mechanism 32 is used to connect with the circumferential surface of the rotating shaft, so that the contact separation type triboelectric power generation mechanism 31 moves with the rotating shaft;

[0044] The contact-separation triboelectric generator mechanism 31 is used to collect airflow energy during the rotation of the shaft and convert the collected airflow energy into electrical energy. It includes a support frame 311 connected to the shaft connection mechanism 32. In this embodiment, the support frame 311 is formed in one piece by 3D printing from polylactic acid polymer material. The support frame 311 (inner diameter 208mm, outer diameter 340mm, width 65mm) has eight arc-shaped through slots 312 arranged side-by-side with identical shape and size. Each arc-shaped through slot 312 extends circumferentially along the shaft, and airflow can pass through it. A first contact-separation triboelectric generator unit and a... are disposed within the arc-shaped through slots 312. The second contact-separated power generation unit, the first contact-separated power generation unit and the second contact-separated power generation unit respectively include a first fixed power generation component 313 and a second fixed power generation component 315 fixedly connected to the arc-shaped through groove 312. Specifically, the first fixed power generation component 313 includes a front fixed copper film attached to the side wall of the arc-shaped through groove 312 by a peelable adhesive. The other side of the front fixed copper film is also attached to a front polymer film by a peelable adhesive. The second fixed power generation component 315 includes a rear fixed copper film attached to the side wall of the arc-shaped through groove 312 by a peelable adhesive. The other side of the rear fixed copper film is also attached to a rear polymer film by a peelable adhesive. In this embodiment, the distance between the front polymer film and the rear polymer film is 5mm.

[0045] The first contact-separated power generation unit and the second contact-separated power generation unit also include a shared movable power generation component 314. The movable power generation component 314 can move within the arc-shaped through-groove 31 along the width direction of the arc-shaped through-groove 31. Specifically, the movable power generation component 314 is a movable copper film with a thickness of 100 micrometers. The movable copper film has through holes, and is connected to the support frame 311 by bolts passing through the through holes. It should be noted that the movable copper film can move along the width direction of the arc-shaped through-groove 312 on the bolts to achieve contact or separation with the front or rear polymer film. The bolts mainly restrict the movement of the movable copper film in the length direction within the arc-shaped through-groove 312, preventing the movable copper film from detaching from the arc-shaped through-groove 312. The movable power generation component 314 is disposed between two first fixed power generation components 313 and second fixed power generation components 315. The movable power generation component 314 can move axially within the arc-shaped through-groove 312 along the axis of rotation (e.g., Figure 1 As shown, along the width direction of the arc-shaped through groove 31, the contact-separated power generation unit is electrically connected to an external circuit to form a closed loop. Both the front and rear polymer films are composed of polytetrafluoroethylene (PTFE), which has excellent chemical stability, electrical insulation, wear resistance, and low coefficient of friction.

[0046] In this embodiment, as Figure 7As shown, the rotating shaft connecting mechanism 32 is a ring-shaped double-row symmetrical bent-ear chain plate. The support frame 311 is fixedly connected to the double-row symmetrical bent-ear chain plate by bolts, and the double-row symmetrical bent-ear chain plate is interference-fitted with the circumference of the rotating shaft. The double-row symmetrical bent-ear chain plate mainly consists of three parts: inner chain plate, pin shaft, and bent plate. Its material is stainless steel, which has good load-bearing capacity.

[0047] In this embodiment, the support frame 311 is a column with fan-shaped annular surfaces on both the upper and lower surfaces. The arc-shaped through groove 312 extends from one radial side of the support frame 311 to the other radial side. The upper and lower surfaces of the support frame 311 face the two cross-sections of the rotating shaft, respectively. The inner arc surface of the support frame 311 is set close to the circumference of the rotating shaft.

[0048] In this embodiment, both the arc-shaped through groove 312 and the movable power generation component 314 are cylindrical structures with fan-shaped annular surfaces on both the upper and lower surfaces, and the thickness of the arc-shaped through groove 312 is greater than the thickness of the movable power generation component 314.

[0049] A shaft-based contact-separation triboelectric power generation method is disclosed, employing a shaft-based contact-separation triboelectric power generation device. The specific process is as follows: When the shaft rotates, it is connected to a support frame 31 via a shaft connection mechanism 32, causing the support frame 311 to begin rotating along the rotation center of the train axle 11. Simultaneously, the movable copper film and the prepolymer film in its arc-shaped groove 312 begin to enter the initial contact stage. Due to the different spatial arrangements of the movable copper film and the prepolymer film in the electrostatic potential sequence, charge transfer occurs between them. The prepolymer film with a high Pauling scale value can capture electrons from the strongly cationic surface of the movable copper film. Therefore, in the interface contact region, the prepolymer film gains excess electrons and becomes electronegative, while the movable copper film surface loses electrons and carries an equal amount of positive charge. At this time, because the electrodes of the movable copper film and the prepolymer film are kept in a direct-connection or load-connected state through an external circuit, the entire system is in an electrically neutral state. When the constant-velocity fluid is disturbed, the moving copper film 33 and the prepolymer film enter the separation stage. Since the interface charge is static, it will remain on the material surface for a period of time under an ideal environment. Therefore, when the moving copper film and the prepolymer film separate, a stable contact potential difference will be formed between the negatively charged prepolymer film and the positively charged moving copper film. To balance the potential difference, using the electrostatic induction effect, the unbound electrons in the moving copper film will be repelled by the negative electrostatic charge of the prepolymer film, while the electrons in the fixed copper film will be attracted. Therefore, electrons will flow from the moving copper film to the fixed copper film through the external load circuit, thus forming a transient current. When the moving copper film and the prepolymer film enter the complete separation stage, the electric field balance between them will be temporarily established, and the conduction current in the external load circuit will no longer flow. In this case, the moving copper film becomes positively charged due to the electron transfer, and the fixed copper film becomes negatively charged due to the gain of electrons. When the active copper film and the prepolymer film enter the re-contact stage, the potential gradient between them gradually decreases because the opposite polarity charges on the surfaces of the active copper film and the prepolymer film attract each other. The charge density distribution formed by the induced charge effect is no longer maintained. As a result, electrons will move in the opposite direction through the external load circuit, flowing from the fixed copper film back to the active copper film, forming a transient current in the opposite direction to the separation stage.

[0050] like Figure 2-6As shown, an application of a shaft-based contact-separation triboelectric generator is illustrated. The shaft-based contact-separation triboelectric generator 3 is installed on a train bogie system 1, specifically comprising a train wheel 12, axle box front cover 18, axle box body 17, train axle 11, bogie side frame 15, intermediate connecting component 16, axle box rear cover 14, brake disc 13, and train axle 11. The train axle 11 is connected to the train wheel 12 via an interference fit (press-fit). The brake disc 13 is splined or keyed to the train axle 11 to prevent relative movement between them, thereby achieving effective braking torque transmission. The axle box body 17 is not directly connected to the train axle 11, but rather "sits" on the journal of the train axle 11 using rolling bearings. The axle box body 17 is bolted to both the axle box front cover 18 and the axle box rear cover 14. The axle box front cover 18 also serves to mount a speed sensor. The axle box 17 is mounted on the bogie side frame 15 via a primary suspension device. The train bogie system 1 as a whole is connected to the upper intermediate connecting component 16 through a center plate, side bearings, or central traction rod. Double-row symmetrical curved lug chain plates are tightly wound around the middle of the train axle 11 with an interference fit to achieve the connection between the contact-separated triboelectric generator 31 and the train axle 11.

[0051] In this embodiment, the detection device includes a flexible sensing mechanism 2, which includes four strain gauges. The four strain gauges are uniformly connected to the circumferential surface of the train wheel axle. The detection device is electrically connected to the contact-separated triboelectric generator mechanism 31 through a single-channel full-bridge transmitter mechanism 4 and an AC-DC converter mechanism.

[0052] Each strain gauge comprises an electrode lead 20, a passivation layer 21, a flexible substrate 22, and a response unit 23. The flexible strain gauge is model BF350-3EB, with a resistance of 350Ω and a substrate size of 10.5 × 9 mm. The flexible substrate 22 is made of special glass fiber. The response unit 23 is a sensitive grid with dimensions of 2.7 mm × 3.2 mm, made of constantan, with a sensitivity coefficient of 2.15 ± 1%. Wire lengths are available in 3 cm / 15 cm / etc. The flexible substrate 22 of the strain gauge is uniformly adhered to the circumferential surface of the train axle 11 using AB strong adhesive. When the train axle 11 begins to rotate at a certain speed, the strain gauge is subjected to external pressure, causing a change in the cross-section of the flexible substrate 22, which in turn causes a change in the passivation layer 21, ultimately resulting in a change in the resistance of the response unit 23. The magnitude of this resistance change is then measured using the wireless acquisition module in the single-channel full-bridge transmitter module 4 and converted into a strain value at the measuring point. The value is then transmitted to the wireless transmission module of the single-channel full-bridge transmitter module 4. In one embodiment, each strain gauge includes electrode leads, a passivation layer, a flexible substrate, and a response unit.

[0053] like Figure 5 As shown, the single-channel full-bridge transmitter mechanism 4 includes an equipment interface cover 40, an RS485 half-duplex differential balanced signal transmitter 41, a chopper step-down circuit 42, and an electronic component bracket 43. Both the equipment interface cover 40 and the electronic component bracket 43 are made of amorphous thermoplastic and manufactured using additive manufacturing. The electronic component bracket 43 has an I-shaped structure with through holes on both its upper and lower ends. The upper end through hole is bolted to the equipment interface cover 40, while the lower end is tightly connected to a double-row symmetrical bent-ear type chain plate using four threaded fasteners. The electronic component bracket 43 has deep slots for mounting the RS485 half-duplex differential balanced signal transmitter 41 and the chopper step-down circuit 42. The RS485 half-duplex differential balanced signal transmitter 41 consists of a voltage divider resistor network, a voltage clamping circuit, an ADC analog-to-digital converter, a microcontroller, a MAX485 chip, a crystal oscillator, a power management circuit, and a PCB antenna. After the RS485 half-duplex differential balanced signal transmitter 41 measures the external voltage, it transmits it to the voltage and protection circuit. The safe analog voltage, after being divided by the voltage divider network, enters the ADC (Analog-to-Digital Converter). The ADC converts this safe analog voltage value into a digital value with a fixed resolution. The microcontroller reads the digital value from the ADC and calculates the original external voltage in reverse. This voltage value is formatted into a data packet containing a start bit, device ID, voltage data, and parity bit. The microcontroller then transmits the data packet to the MAX485 chip via a serial communication protocol. The MAX485 chip encapsulates the data packet and radiates it through the PCB antenna. The remote device receives the data packet through its antenna interface. The chopper-step-down circuit 42 mainly consists of MOSFETs, synchronous rectifier diodes, inductors, output capacitors, a PWM controller chip, a feedback resistor network, and input capacitors. The electrodes of the AC-DC converter mechanism 5 are connected to the input ports of the chopper-step-down circuit 42 and provide a stable voltage for the single-channel full-bridge transmitter structure 4.

[0054] like Figure 6 As shown, the AC-DC converter mechanism 5 includes a semiconductor rectifier network 50, a power transformer 51, a low-pass filter network 52, a storage capacitor 53, and an energy harvester model 54. The core function of the semiconductor rectifier network 50 is to guide and trim the polarity and period of the AC signal output from the energy harvester model 54, thereby achieving AC-DC signal conversion. The power transformer 51 performs basic voltage conversion and electrical isolation, ensuring the safety and compatibility of subsequent circuits. The low-pass filter network 52 is generally composed of a high-capacity capacitor and an inductor, suppressing the ripple of the violently fluctuating pulsed DC after AC-DC conversion. Finally, the output DC signal is transmitted to the storage capacitor 53, where the charging and discharging effect of the capacitor suppresses the output voltage ripple, thus obtaining a sufficiently stable DC voltage that meets application requirements.

[0055] The working process and principle of this invention are as follows:

[0056] When the train runs at a certain speed, the train wheels 12 rotate at a corresponding speed, and the train axle 11, which is connected to the train wheels 12 by an interference fit (press fitting), also begins to rotate. It is worth noting that the double-row symmetrical curved lug-shaped chain plates tightly wound around the middle of the train axle 11 will produce the same motion state. The support frame 311 of the contact-separation triboelectric generator mechanism 31 is fastened to the double-row symmetrical curved lug-shaped chain plates by bolts. The support frame 311 has eight arc-shaped through slots 312 of the same shape. Each arc-shaped through slot 312 is equipped with a first contact-separation generator unit and a second contact-separation generator unit that are in contact with each other. When the support frame 311 rotates around the rotation center of the train axle, the movable copper film and the front polymer film in its arc-shaped through slot 312 begin to enter the initial contact stage. Due to the different spatial arrangement of the movable copper film and the front polymer film in the electrostatic potential sequence, charge transfer will be initiated between them. The front polymer film with a high Pauling scale value can capture electrons from the surface of the strongly cationic movable copper film. Therefore, at the interface contact region, the prepolymer film gains excess electrons and becomes electronegative, while the surface of the movable copper film loses electrons and carries an equal amount of positive charge. At this time, since the two electrodes of the movable copper film and the prepolymer film are kept in a direct-connection or load-connected state through an external circuit, the entire system is in an electrically neutral state. When the constant-velocity fluid is disturbed, the movable copper film and the prepolymer film enter the separation stage. Since the interface charge is static, it will remain on the material surface for a period of time under the assumption of an ideal environment. Therefore, when the movable copper film and the prepolymer film separate, a stable contact potential difference will be formed between the negatively charged prepolymer film and the positively charged movable copper film. In order to balance the potential difference, using the electrostatic induction effect, the unbound electrons in the movable copper film will be repelled by the negative electrostatic charge of the prepolymer film, while the electrons in the fixed copper film will be attracted. Therefore, electrons will flow from the movable copper film to the fixed copper film through the external load circuit, thus forming a transient current. When the moving copper film and the prepolymer film enter the complete separation stage, a temporary electric field balance is established between them, and the conduction current in the external load circuit ceases to flow. Under these conditions, the moving copper film becomes positively charged due to electron transfer, while the fixed copper film becomes negatively charged due to the gain of electrons. When the moving copper film and the prepolymer film enter the re-contact stage, the potential gradient between them gradually decreases due to the attraction between the oppositely polar charges on their surfaces. The charge density distribution previously formed due to the induced charge effect is no longer maintained, and electrons will move in the opposite direction through the external load circuit, flowing from the fixed copper film back to the moving copper film, forming a transient current in the opposite direction to that in the separation stage.The voltage output from the contact-separated triboelectric generator mechanism 31 is continuously input to the AC-DC converter mechanism 5. The AC-DC converter mechanism 5 first converts the voltage to AC-DC, then suppresses the violently fluctuating pulsed DC ripple, and then transmits the output voltage to the storage capacitor. The charging and discharging effect of the capacitor suppresses the output voltage ripple. Finally, the voltage is output to the single-channel full-bridge transmitter mechanism 4. The acquisition module of the single-channel full-bridge transmitter mechanism 4 is interconnected with the flexible sensing mechanism 2 through electrode leads. The flexible substrate 22 of the flexible resistance strain gauge is uniformly attached to the circumferential surface of the train axle 11 with AB strong adhesive. Due to the external pressure, the cross-section of the flexible substrate 22 of the strain gauge changes, which in turn causes the passivation layer 21 to change, ultimately causing a change in the resistance of the response unit 23. The circuit module then measures the magnitude of the resistance change and converts it into the strain value of the measuring point. Subsequently, this value is transmitted to the host computer through the RS485 half-duplex differential balanced signal transmitter 41 of the single-channel full-bridge transmitter mechanism 4. The host computer then performs real-time analysis and processing of the signals to ultimately determine whether the axle's operating status is normal.

[0057] In this embodiment, the debugging software interface is shown as follows: Figure 8 As shown, from Figure 8 As can be seen, the baud rate is set to 9600, the port number matches the computer's port number, and then click "Connect." The Modbus communication address is 1. To select microstrain data, simply select "Microstrain Measurement" in the main interface of the debugging software, then select single-bridge (1 / 4-bridge), with a strain gauge resistance of 120Ω, a sensitivity of 2, and strain gauge placement method 1. Then select continuous acquisition, and finally, the output curve can be viewed on the computer.

[0058] The embodiments described above merely illustrate specific implementation methods of this application, and while the descriptions are detailed and specific, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the technical solution of this application, and these modifications and improvements all fall within the scope of protection of this application.

Claims

1. A contact-separation triboelectric power generation device based on a rotating shaft, characterized in that: include: A rotating shaft connecting mechanism (32) is used to connect to the circumferential surface of a rotating shaft; A contact-separation triboelectric generator (31) is used to collect air fluid energy during the rotation of a rotating shaft and convert the collected air fluid energy into electrical energy. It includes a support frame (311) connected to a rotating shaft connection mechanism (32). At least one arc-shaped through-slot (312) is provided within the support frame (311). The arc-shaped through-slot (312) extends circumferentially along the rotating shaft, and air fluid can pass through the arc-shaped through-slot (312). A first contact-separation triboelectric generator unit and a second contact-separation triboelectric generator unit are provided within the arc-shaped through-slot (312). The unit includes a first fixed power generation component (313) and a second fixed power generation component (315) fixedly connected to the arc-shaped through groove (312). The first contact-separated power generation unit and the second contact-separated power generation unit also include a common movable power generation component (314). The movable power generation component (314) is disposed between the two first fixed power generation components (313) and the second fixed power generation component (315). The movable power generation component (314) can move along the axial direction of the rotating shaft in the arc-shaped through groove (312). The first contact-separated power generation unit and the second contact-separated power generation unit are electrically connected to an external circuit to form a closed loop.

2. The contact-separation triboelectric power generation device based on a rotating shaft according to claim 1, characterized in that: The rotating shaft connection mechanism (32) is a ring-shaped double-row symmetrical bent-ear type chain plate. The support frame (311) is fixedly connected to the double-row symmetrical bent-ear type chain plate by bolts. The double-row symmetrical bent-ear type chain plate is interference-fitted with the circumference of the rotating shaft.

3. The contact-separation triboelectric power generation device based on a rotating shaft according to claim 2, characterized in that: The support frame (311) is a column with fan-shaped annular surfaces on both the upper and lower surfaces. The arc-shaped through groove (312) extends from one radial side of the support frame (311) to the other radial side. The upper and lower surfaces of the support frame (311) face the two cross sections of the rotating shaft respectively. The inner arc surface of the support frame (311) is set close to the circumference of the rotating shaft.

4. The contact-separation triboelectric power generation device based on a rotating shaft according to claim 2, characterized in that: Both the arc-shaped through groove (312) and the movable power generation component (314) are columnar structures with fan-shaped annular surfaces on both the upper and lower surfaces, and the thickness of the arc-shaped through groove (312) is greater than the thickness of the movable power generation component (314).

5. A contact-separation triboelectric generator based on a rotating shaft according to any one of claims 1-4, characterized in that: The first fixed power generation component (313) includes a front fixed copper film fixedly connected to the side wall of the arc-shaped through groove (312), and a front polymer film is also connected to the front fixed copper film. The second fixed power generation component (315) includes a rear fixed copper film fixedly connected to the side wall of the arc-shaped through groove (312), and a rear polymer film is also connected to the rear fixed copper film. The movable power generation component (314) is a movable copper film, which is located between the front polymer film and the rear polymer film.

6. A contact-separation triboelectric power generation method based on a rotating shaft, characterized in that: The contact separation triboelectric generator based on the rotating shaft as described in any one of claims 1-5 is used. The specific process is as follows: when the rotating shaft rotates, the supporting frame (311) is driven to rotate through the rotating shaft connecting mechanism (32). During the rotation, the movable generator (314) moves under the excitation of the air fluid and comes into contact or separates with the first fixed generator (313) or the second fixed generator (315), thereby generating current.

7. An application of the contact-separation triboelectric power generation device based on a rotating shaft as described in any one of claims 1-5, characterized in that: The contact-separation triboelectric generator (3) based on the rotating shaft is installed on the train axle (11) to power the detection device for detecting the operating status of the train axle (11) and output the operating status sensing signal of the train axle (11).

8. The application of the contact-separation triboelectric power generation device based on a rotating shaft according to claim 7, characterized in that: The detection device includes a flexible sensing mechanism (2), which includes several strain gauges. The strain gauges are uniformly connected to the circumferential surface of the train wheel axle. The detection device is electrically connected to the contact-separated triboelectric generator mechanism (31) through a single-channel full-bridge transmitter mechanism (4) and an AC-DC converter mechanism.

9. The application of the contact-separation triboelectric power generation device based on a rotating shaft according to claim 8, characterized in that: Each strain gauge includes electrode leads, a passivation layer, a flexible substrate, and a response unit.

10. The application of the contact-separation triboelectric power generation device based on a rotating shaft according to claim 8, characterized in that: The AC-DC converter mechanism and the single-channel full-bridge transmitter mechanism (4) are connected to the rotating shaft connection mechanism (32) and / or the support frame (311).

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