Friction nano generator for capturing bridge vibration energy and monitoring in situ

Abstract

The invention belongs to the field of nano-generators, and particularly relates to a friction nano-generator for capturing bridge vibration energy and performing in-situ monitoring. According to the technical scheme, the friction nanometer generator for capturing bridge vibration energy and conducting in-situ monitoring comprises a shell assembly, a transmission unit, a friction electricity generating unit, an electromagnetic generating unit and a friction electricity monitoring unit, and the transmission unit, the friction electricity generating unit, the electromagnetic generating unit and the friction electricity monitoring unit are arranged in the shell assembly; the transmission unit transmits bridge vibration energy to the triboelectricity power generation unit and the electromagnetic power generation unit for power generation, and the triboelectricity monitoring unit is used for monitoring the bridge vibration state. The friction nano-generator for capturing bridge vibration energy and in-situ monitoring can capture bridge vibration energy, supply power to sensing equipment of a bridge and perform real-time monitoring.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of nanogenerators, and particularly relates to a friction nanogenerator for capturing bridge vibration energy and in-situ monitoring. BACKGROUND

[0002] Bridges are prone to be affected by external factors (such as vehicle load, wind load, environment, etc.) to produce vibration, and the vibration energy produced by the bridges is very rich, which is an ideal place for vibration energy capture. Some traditional bridge sensors cannot monitor the vibration environment in real time, and in practical applications, most of the sensors need external power supply, and have the problem of wiring difficulty. In order to solve the challenges encountered by the bridge monitoring system in power supply, it is urgent to explore new solutions. SUMMARY

[0003] The application provides a friction nanogenerator for capturing bridge vibration energy and in-situ monitoring, which can capture bridge vibration energy and power the sensing device of the bridge and monitor in real time.

[0004] The technical scheme of the application is as follows:

[0005] The friction nanogenerator for capturing bridge vibration energy and in-situ monitoring comprises a shell assembly, a transmission unit, a triboelectric power generation unit, an electromagnetic power generation unit and a triboelectric monitoring unit, the transmission unit, the triboelectric power generation unit, the electromagnetic power generation unit and the triboelectric monitoring unit are arranged in the shell assembly; the transmission unit transmits the bridge vibration energy to the triboelectric power generation unit and the electromagnetic power generation unit to generate electricity, and the triboelectric monitoring unit is used to monitor the vibration state of the bridge.

[0006] Further, the friction nanogenerator for capturing bridge vibration energy and in-situ monitoring comprises an upper shell, a middle shell and a lower shell, the middle shell and the lower shell are fixedly connected together, and the upper shell is sleeved on the middle shell.

[0007] Further, the friction nanogenerator for capturing bridge vibration energy and in-situ monitoring, the transmission unit includes transmission rods, springs, sliding blocks, lead screws, nuts, large gears, small gears and energy capturing shafts, the upper ends of the two transmission rods are fixedly connected with the top wall of the upper shell, the lower ends of the two transmission rods are fixedly connected with the sliding blocks through the top wall of the middle shell, the springs are sleeved on the transmission rods and located between the top wall of the upper shell and the top wall of the middle shell; the two ends of the two lead screws are rotatably connected with the top wall and the bottom wall of the middle shell respectively, the two nuts are screwed on the two lead screws respectively, and the sliding blocks and the two nuts are fixedly connected together; the two large gears are fixedly installed at the lower ends of the two lead screws respectively; the energy capturing shafts are rotatably connected with the bottom wall of the middle shell and the bottom wall of the lower shell respectively, the upper ends of the energy capturing shafts protrude out of the bottom wall of the middle shell, the small gears are fixedly installed at the upper ends of the energy capturing shafts, and the two large gears are engaged with the small gears.

[0008] Further, the friction nanogenerator for capturing bridge vibration energy and in-situ monitoring, the triboelectric power generation unit includes a rotor, a one-way bearing, a power generation FEP film, a power generation copper electrode and a stator; the rotor is a sleeve structure including a rotor inner cylinder, a rotor outer cylinder and a rotor bottom wall, the rotor inner cylinder and the rotor outer cylinder are connected together through the rotor bottom wall, and the rotor inner cylinder is rotatably connected with the energy capturing shaft through the one-way bearing; the outer walls of the rotor inner cylinder and the rotor outer cylinder are provided with uniformly distributed grooves, and one end of the power generation FEP film is fixedly arranged in the grooves; the stator is a sleeve structure including a stator inner cylinder and a stator outer cylinder, and the stator inner cylinder and the stator outer cylinder are fixedly connected with the bottom wall of the middle shell together; the inner walls of the stator inner cylinder and the stator outer cylinder are provided with uniformly distributed power generation copper electrodes; the rotor and the stator are sleeved together, the rotor inner cylinder is located at the innermost part, the stator inner cylinder is located between the rotor inner cylinder and the rotor outer cylinder, and the stator outer cylinder is located at the outermost part.

[0009] Further, the friction nanogenerator for capturing bridge vibration energy and in-situ monitoring, the outer wall of the rotor inner cylinder is provided with four grooves one, and four power generation FEP films one are arranged in the four grooves one respectively; the outer wall of the rotor outer cylinder is provided with eight grooves two, and eight power generation FEP films two are arranged in the eight grooves two respectively; the inner wall of the stator inner cylinder is provided with eight power generation copper electrodes one; and the inner wall of the stator outer cylinder is provided with sixteen power generation copper electrodes two.

[0010] Further, the friction nanogenerator for capturing bridge vibration energy and in-situ monitoring, the electromagnetic power generation unit includes magnets and copper coils, four magnets are fixedly installed on the rotor bottom wall in a uniform manner, and four copper coils are fixedly arranged on the bottom wall of the lower shell in a uniform manner.

[0011] Further, the friction nanogenerator for capturing bridge vibration energy and in-situ monitoring, the four magnets are arranged in an alternating manner of N-pole and S-pole.

[0012] Further, the friction nanogenerator for capturing bridge vibration energy and in-situ monitoring, the friction electricity monitoring unit includes interdigital copper electrodes and arch-shaped FEP film, the interdigital copper electrodes are fixedly arranged on the inner wall of the middle shell, and the arch-shaped FEP film is fixedly arranged on the sliding block.

[0013] Further, the friction nanogenerator for capturing bridge vibration energy and in-situ monitoring, the number of interdigital copper electrodes is 38 pairs; and the number of arch-shaped FEP films is 10 pairs.

[0014] Further, the friction nanogenerator for capturing bridge vibration energy and in-situ monitoring, the upper shell and the middle shell are both split structures and are connected through a bolt pair.

[0015] The working principle of the friction nanogenerator for capturing bridge vibration energy and in-situ monitoring is as follows:

[0016] The friction nanogenerator is placed between the pier and the beam of the bridge, the lower shell is fixedly connected with the pier, and the upper end of the upper shell is in contact with the bridge; when the bridge is in a static state, the friction nanogenerator is in a non-working state.

[0017] When the bridge is excited by external excitation and vibrates, the friction nanogenerator is started and begins to work; in the vibration triggering stage, the bridge compresses the upper shell to move downward, the spring is compressed due to the pressure; the upper shell drives the sliding block to move downward synchronously, the sliding block drives the lead screw to rotate, the lead screw drives the large gear to rotate counterclockwise, the large gear drives the small gear to rotate clockwise, the small gear drives the energy capturing shaft to rotate clockwise, and the energy capturing shaft drives the rotor to rotate clockwise, so as to activate the triboelectric power generation unit and the electromagnetic power generation unit, and start to convert mechanical vibration energy into electrical energy.

[0018] In the vibration recovery stage, when the bridge vibration gradually weakens and recovers to the original position, the upper shell drives the sliding block to move upward under the action of the spring, the lead screw reversely rotates to drive the large gear to rotate clockwise, and the small gear drives the energy capturing shaft to rotate counterclockwise; due to the existence of the one-way bearing, the energy capturing shaft cannot drive the rotor to rotate counterclockwise, and the rotor remains in a static state; at this time, the triboelectric power generation unit and the electromagnetic power generation unit still work due to the inertial effect, and continuously output electrical energy.

[0019] During the vibration of the bridge, the triboelectric monitoring unit is always in a working state, and the vibration state of the bridge is monitored in real time, so as to provide data support for bridge health monitoring.

[0020] The friction nanogenerator for capturing bridge vibration energy and in-situ monitoring has the following beneficial effects:

[0021] 1. This invention can effectively capture the vibration energy generated by bridge vibration and convert it into electrical energy output, and can also use the output electrical signal to monitor the vibration state of the bridge.

[0022] 2. This invention utilizes a combination of double lead screws and gears to convert the low-frequency vibration of the bridge into high-speed rotational motion of each power generation unit, thereby achieving a more stable and efficient power output from the composite sensing device and solving the problem of low efficiency of triboelectric nanogenerators in collecting bridge vibration energy.

[0023] 3. The triboelectric monitoring unit in this invention can perform displacement monitoring and display the collected vibration information through LabVIEW program, thereby realizing visualization and early warning of bridge vibration, providing new ideas and methods for in-situ monitoring and early warning of triboelectric nanogenerators. Attached Figure Description

[0024] Figure 1 An external view of a triboelectric nanogenerator used for capturing bridge vibration energy and in-situ monitoring.

[0025] Figure 2 A front cross-sectional view of a triboelectric nanogenerator used for capturing bridge vibration energy and in-situ monitoring.

[0026] Figure 3 This is an exploded schematic diagram of the lower casing and the triboelectric power generation unit and the electromagnetic power generation unit.

[0027] Figure 4 for Figure 3 Cross-sectional view at point AA. Detailed Implementation

[0028] like Figures 1-4 As shown, a triboelectric nanogenerator for capturing bridge vibration energy and in-situ monitoring includes a housing assembly, a transmission unit, a triboelectric power generation unit, an electromagnetic power generation unit, and a triboelectric monitoring unit. The transmission unit, triboelectric power generation unit, electromagnetic power generation unit, and triboelectric monitoring unit are disposed within the housing assembly. The transmission unit transmits the bridge vibration energy to the triboelectric power generation unit and the electromagnetic power generation unit to generate electricity, and the triboelectric monitoring unit is used to monitor the bridge vibration state.

[0029] The housing assembly includes an upper housing 1, a middle housing 2, and a lower housing 3. The middle housing 2 and the lower housing 3 are fixedly connected together, and the upper housing 1 is fitted onto the middle housing 2. Both the upper housing 1 and the middle housing 2 are split structures and are connected by bolt pairs.

[0030] The transmission unit comprises transmission rods 4, springs 5, sliding blocks 6, lead screws 7, nuts, large gears 8, pinions and energy capturing shafts 9, the upper ends of the two transmission rods 4 are fixedly connected with the top wall of the upper shell 1, the lower ends of the two transmission rods 4 pass through the top wall of the middle shell 2 and are fixedly connected with the sliding blocks 6, the springs 5 are sleeved on the transmission rods 4 and located between the top wall of the upper shell 1 and the top wall of the middle shell 2, the two ends of the two lead screws 7 are rotatably connected with the top wall and the bottom wall of the middle shell 2 respectively, the two nuts are screwed on the two lead screws 7 respectively, the sliding blocks 6 and the two nuts are fixedly connected together, the two large gears 8 are fixedly installed at the lower ends of the two lead screws 7 respectively, the energy capturing shafts 9 are rotatably connected with the bottom wall of the middle shell 2 and the bottom wall of the lower shell 3 respectively, the upper ends of the energy capturing shafts 9 project out of the bottom wall of the middle shell 2, the pinions are fixedly installed at the upper ends of the energy capturing shafts 9, and the two large gears 8 are engaged with the pinions.

[0031] The triboelectric power generation unit comprises a rotor 10, one-way bearings 13, FEP films, copper electrodes and a stator 11, the rotor 10 is a sleeve structure comprising a rotor inner cylinder 14, a rotor outer cylinder 15 and a rotor bottom wall, the rotor inner cylinder 14 and the rotor outer cylinder 15 are connected together through the rotor bottom wall, the rotor inner cylinder 14 is rotatably connected with the energy capturing shaft 9 through the one-way bearings 13, the stator 11 is a sleeve structure comprising a stator inner cylinder 16 and a stator outer cylinder 17, the stator inner cylinder 16 and the stator outer cylinder 17 are fixedly connected together with the bottom wall of the middle shell 2, the rotor 10 is sleeved with the stator 11, the rotor inner cylinder 14 is located at the innermost part, the stator inner cylinder 16 is located between the rotor inner cylinder 14 and the rotor outer cylinder 15, and the stator outer cylinder 17 is located at the outermost part, the outer wall of the rotor inner cylinder 14 is provided with four evenly distributed grooves one, four FEP films one 18 are arranged in the four grooves one respectively, the outer wall of the rotor outer cylinder 15 is provided with eight evenly distributed grooves two, eight FEP films two 19 are arranged in the eight grooves two respectively, the inner wall of the stator inner cylinder 16 is provided with eight evenly distributed copper electrodes one 20, and the inner wall of the stator outer cylinder 17 is provided with sixteen evenly distributed copper electrodes two 21.

[0032] The electromagnetic power generation unit comprises magnets and copper coils 12, four magnets are fixedly installed on the rotor bottom wall in a uniform manner, and four copper coils 12 are fixedly arranged on the bottom wall of the lower shell 3 in a uniform manner, the four magnets are arranged in an alternating manner of N-pole and S-pole.

[0033] The triboelectric monitoring unit comprises interdigital copper electrodes 22 and arch-shaped FEP films, the interdigital copper electrodes 22 are fixedly arranged on the inner wall of the middle shell 2, and the arch-shaped FEP films are fixedly arranged on the sliding blocks 6, the number of the interdigital copper electrodes 22 is 38 pairs, and the number of the arch-shaped FEP films is 10 pairs.

[0034] The working process is as follows: When the bridge is stationary, the triboelectric nanogenerator is in a non-operating state. When the bridge is subjected to external excitation and vibrates, the triboelectric nanogenerator starts up and begins to work.

[0035] During the vibration triggering phase, the bridge compresses the upper shell 1 to move downwards, causing the upper shell 1 to move the sliding block 6 downwards synchronously, and the spring 5 is compressed due to the pressure; the sliding block 6 causes the lead screw 7 to start rotating, causing the large gear 8 to rotate counterclockwise, the counterclockwise rotation of the large gear 8 drives the small gear to rotate clockwise, the small gear drives the energy-harvesting shaft 9 to rotate clockwise, and the energy-harvesting shaft 9 drives the rotor 10 to rotate clockwise, thereby activating the triboelectric power generation unit; the power generation FEP film makes full contact with the first power generation copper electrode, electron transfer occurs and charge balance is established; then, the power generation FEP film slides to the adjacent second power generation copper electrode, generating a directional current from the first power generation copper electrode to the second power generation copper electrode in the external circuit; in turn, it makes contact with the subsequent power generation copper electrodes, forming a new charge balance state; during the reset phase, the power generation FEP film returns to the initial position, completing a complete working cycle.

[0036] When the rotor 10 rotates, a periodic alternating current is generated in the copper coil 12. When the electromagnetic field moves from the overlapping state to the crossing state, and the relative distance between the magnet and the copper coil 12 shortens, an induced current in a specific direction will be formed in the circuit of the copper coil 12 based on the principle of electromagnetic induction. This energy conversion process originates from the change in magnetic field strength, which leads to the generation of electromotive force in the closed conductor. When the electromagnetic field moves from the crossing state to the overlapping state, the copper coil 12 will generate a corresponding reverse current.

[0037] Throughout the entire bridge vibration process, the triboelectric monitoring unit remained operational, monitoring the bridge's vibration status in real time and providing data support for bridge health monitoring.

[0038] Experimental results show that the triboelectric power generation unit has a maximum peak open-circuit voltage of 496V, a maximum short-circuit current of 59.3μA, a maximum transferred charge of 230nC, and a peak power of 6.21mW; the electromagnetic power generation unit has a maximum peak open-circuit voltage of 41V, a maximum short-circuit current of 0.283A, and a peak power of 10mW, which is sufficient to power 462 series-connected light-emitting diodes or temperature and humidity sensors.

Claims

1. A triboelectric nanogenerator for capturing bridge vibration energy and in-situ monitoring, characterized in that, It includes a housing assembly, a transmission unit, a triboelectric power generation unit, an electromagnetic power generation unit, and a triboelectric monitoring unit. The transmission unit, triboelectric power generation unit, electromagnetic power generation unit, and triboelectric monitoring unit are housed within the housing assembly. The transmission unit transmits the bridge vibration energy to the triboelectric power generation unit and the electromagnetic power generation unit to generate electricity. The triboelectric monitoring unit is used to monitor the bridge vibration status.

2. The triboelectric nanogenerator for capturing bridge vibration energy and in-situ monitoring according to claim 1, characterized in that, The housing assembly includes an upper housing, a middle housing, and a lower housing. The middle housing and the lower housing are fixedly connected together, and the upper housing is fitted onto the middle housing.

3. The triboelectric nanogenerator for capturing bridge vibration energy and in-situ monitoring according to claim 2, characterized in that, The transmission unit includes transmission rods, springs, sliding blocks, lead screws, lead nuts, large gears, small gears, and energy-harvesting shafts. The upper ends of the two transmission rods are fixedly connected to the top wall of the upper housing, and the lower ends of the two transmission rods pass through the top wall of the middle housing and are fixedly connected to the sliding blocks. The springs are fitted onto the transmission rods and are located between the top walls of the upper and middle housings. The two ends of the two lead screws are rotatably connected to the top and bottom walls of the middle housing, respectively. The two lead nuts are screwed onto the two lead screws, respectively, and the sliding block is fixedly connected to the two lead nuts. The two large gears are fixedly installed at the lower ends of the two lead screws. The energy-harvesting shaft is rotatably connected to the bottom walls of the middle and lower housings, respectively. The upper end of the energy-harvesting shaft protrudes from the bottom wall of the middle housing, and the small gear is fixedly installed at the upper end of the energy-harvesting shaft. Both large gears mesh with the small gear.

4. The triboelectric nanogenerator for capturing bridge vibration energy and in-situ monitoring according to claim 3, characterized in that, The triboelectric power generation unit includes a rotor, a one-way bearing, a power-generating FEP film, power-generating copper electrodes, and a stator. The rotor is a sleeve structure, including an inner rotor cylinder, an outer rotor cylinder, and a bottom wall. The inner and outer rotor cylinders are connected together through the bottom wall, and the inner rotor cylinder is rotatably connected to the energy-harvesting shaft through the one-way bearing. The outer walls of the inner and outer rotor cylinders have evenly distributed grooves, and one end of the power-generating FEP film is fixedly disposed in one of these grooves. The stator is a sleeve structure, including an inner stator cylinder and an outer stator cylinder, which are fixedly connected to the bottom wall of the middle housing. The inner walls of the inner and outer stator cylinders have evenly distributed power-generating copper electrodes. The rotor and stator are fitted together, with the inner rotor cylinder located at the innermost point, the inner stator cylinder located between the inner and outer rotor cylinders, and the outer stator cylinder located at the outermost point.

5. The triboelectric nanogenerator for capturing bridge vibration energy and in-situ monitoring according to claim 4, characterized in that, The outer wall of the rotor inner cylinder has four evenly distributed grooves, and four FEP films for power generation are respectively disposed in the four grooves. The outer wall of the rotor outer cylinder has eight evenly distributed grooves, and eight FEP films for power generation are respectively disposed in the eight grooves. The inner wall of the stator inner cylinder has eight evenly distributed copper electrodes for power generation. The inner wall of the stator outer cylinder has sixteen evenly distributed copper electrodes for power generation.

6. The triboelectric nanogenerator for capturing bridge vibration energy and in-situ monitoring according to claim 4, characterized in that, The electromagnetic power generation unit includes magnets and copper coils. Four magnets are evenly fixed on the bottom wall of the rotor, and four copper coils are evenly fixed on the bottom wall of the lower housing.

7. The triboelectric nanogenerator for capturing bridge vibration energy and in-situ monitoring according to claim 6, characterized in that, The four magnets are arranged with alternating N and S poles.

8. The triboelectric nanogenerator for capturing bridge vibration energy and in-situ monitoring according to claim 3, characterized in that, The triboelectric monitoring unit includes interdigitated copper electrodes and an arched FEP film. The interdigitated copper electrodes are fixedly mounted on the inner wall of the middle housing, and the arched FEP film is fixedly mounted on the sliding block.

9. The triboelectric nanogenerator for capturing bridge vibration energy and in-situ monitoring according to claim 8, characterized in that, The number of interdigitated copper electrodes is 38 pairs; the number of arched FEP films is 10 pairs.

10. The triboelectric nanogenerator for capturing bridge vibration energy and in-situ monitoring according to claim 3, characterized in that, Both the upper and middle shells are split structures and are connected by bolt pairs.

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