WO2024082335A1 - Arrayed electromagnetic-friction composite vibration energy collection device - Google Patents

Abstract

An arrayed electromagnetic-friction composite vibration energy collection device, comprising: a housing (1); and a vibration energy collection mechanism, comprising a plurality of vibration energy collection units (2) arranged in an array in the housing (1), each vibration energy collection unit (2) comprising a spring vibration pickup unit (3), an electromagnetic power generation unit (4), and a friction power generation unit (5); the spring vibration pickup unit (3) comprises a vibration pickup body (31) and a plurality of springs (32), one end of each spring (32) is connected to the outer surface of the vibration pickup body (31), and the other end is connected to the inner surface of the housing (1); the electromagnetic power generation unit (4) comprises a magnet unit (41) and a coil (42), the magnet unit (41) is provided in the vibration pickup body (31), the magnet unit (41) comprises two magnets (411) arranged opposite to one another in the vertical direction, the magnetic poles of the two magnets (411) repel one another, and the coil (42) surrounds the vibration pickup body (31) and is connected to the inner surface of the housing (1); and the friction power generation unit (5) is connected to the outer surface of the vibration pickup body (31). Vibration excitation in any direction on the outside can be converted into electric energy to be outputted; and by means of arrayed design, the working frequency band is widened.

Description

Arrayed electromagnetic-friction composite vibration energy harvesting device Technical Field

The present invention relates to the technical field of energy collection, and in particular to an arrayed electromagnetic-friction composite vibration energy collection device.

Background technique

As the era of the Internet of Everything begins, the demand for various sensors for interactive communication has increased dramatically. As the lifeblood of the sensor system, reliable energy supply is a key factor in the interactive communication network. However, most wireless sensor network nodes are still powered by batteries. On the one hand, the limited life of the battery poses a huge challenge to the replacement or charging of batteries in massive wireless sensor network nodes; on the other hand, chemical batteries are not only difficult to withstand harsh environments such as high and low temperatures, but also cause pollution to the environment. Therefore, the power supply problem of wireless sensor network nodes has become a bottleneck restricting the construction of the Internet of Things. Environmental vibration energy is a renewable clean energy with abundant reserves and widespread distribution. Through energy harvesting technology, the mechanical energy in the environment is converted into electrical energy to power wireless sensor network nodes, which is an effective solution to break the limitations of traditional power supply methods.

Vibration energy harvesting technology uses vibration energy harvesters to convert mechanical vibration energy in the environment into electrical energy. At present, several electromechanical transduction mechanisms include piezoelectric effect, electromagnetic induction and triboelectric effect. Vibration energy harvesters designed using the above electromechanical transduction mechanisms are usually called piezoelectric, electromagnetic and triboelectric vibration energy harvesters. Piezoelectric vibration energy harvesters use the positive piezoelectric effect of piezoelectric materials to generate electrical energy. Piezoelectric energy harvesters can generate higher output power, but piezoelectric materials have low toughness and are prone to fracture. Electromagnetic vibration energy harvesters work based on Faraday's law of electromagnetic induction. The change in magnetic flux in the coil generates an induced electromotive force. Electromagnetic energy harvesting technology is relatively mature and has been realized in large-scale systems. However, since the performance of the magnet is limited by space and vibration amplitude, the output of the device is relatively small and the integration is not high. Triboelectric vibration energy harvesters work based on triboelectric charging and electrostatic induction phenomena. Triboelectric power generation technology uses the difference in the ability of different materials to gain and lose electrons to form charge transfer during contact friction, generate potential difference, and have the characteristics of low output current and high voltage. Energy harvesters with a single conversion mechanism usually have problems with poor stability or low energy collection efficiency. In recent years, the emerging electromagnetic-friction composite energy harvesting technology has been proven to be an effective way to achieve efficient acquisition and conversion of vibration energy. Triboelectric nanogenerators (TENGs) have a high output voltage, but the output current is only in the microampere level, while the output current of electromagnetic generators (EMGs) can reach the milliampere level. The combination of the two can meet the needs of higher energy conversion.

technical problem

Although electromagnetic-friction composite vibration energy harvesting technology has made some progress in recent years, its engineering application still faces many challenges: (1) Existing energy harvesting devices can only have good output in a single frequency band and regular vibration environment, while random and irregular environmental vibrations often have low output, making it difficult to achieve efficient acquisition and conversion of vibration energy in different frequency bands and directions; (2) Most energy harvesting devices use sliding structures with high friction resistance and low sensitivity, and have poor response to low-frequency weak environmental vibrations; how to ensure that the energy harvester has a wider energy capture freedom and a wider response frequency band under the condition of high power density output is a technical problem that needs to be solved urgently.

Technical Solutions

In view of the shortcomings of the prior art, the purpose of the present invention is to provide an arrayed electromagnetic-friction composite vibration energy collection device.

In order to achieve the above object, a technical solution provided by an embodiment of the present invention is as follows:

An arrayed electromagnetic-friction composite vibration energy collection device, comprising:

shell;

A vibration energy collection mechanism, the vibration energy collection mechanism comprising a plurality of vibration energy collection units, the plurality of vibration energy collection units being arranged in an array in the housing, each of the vibration energy collection units comprising a spring vibration pickup unit, an electromagnetic power generation unit and a friction power generation unit;

The spring vibration pickup unit comprises a vibration pickup body and a plurality of springs, one end of each of the springs being connected to the outer surface of the vibration pickup body and the other end being connected to the inner surface of the housing;

The electromagnetic power generation unit includes a magnet unit and a coil. The magnet unit is arranged in the vibration pickup body. The magnet unit includes two magnets arranged opposite to each other in a vertical direction. The magnetic poles of the two magnets repel each other. The coil is arranged outside the vibration pickup body and connected to the inner surface of the shell.

The friction power generation unit is connected to the outer surface of the vibration pickup body.

Beneficial Effects

(1) The spring vibration pickup unit of the device is a four-spring vibration pickup unit, with four springs distributed in four directions of the vibration pickup body. The spring vibration pickup unit has multi-degree-of-freedom and multi-modal vibration characteristics, which can convert the vibration energy of the external multi-direction and multi-frequency band into the movement of the vibration pickup body in all directions, forming a multi-degree-of-freedom vibration energy collection device, which can collect more energy than a single-degree-of-freedom or several-degree-of-freedom energy collection device, thereby improving the device's efficiency in capturing external energy.

(2) When the vibration pickup moves in the shell in response to external vibration energy, the position of the magnet in the vibration pickup changes, causing the magnetic flux in the coil to change, generating an induced electromotive force, and completing electromagnetic power generation. Introducing nano-friction generators in multiple directions of the vibration pickup, vibration excitation in any direction in the external environment can be converted into frictional electric output of the vibration pickup to the origami structure in all directions. The frictional power generation unit can be used as an energy supplement when the electromagnetic power generation efficiency is low due to insufficient amplitude of the vibration pickup movement. Therefore, the vibration energy collection device can simultaneously convert vibration energy in any direction into electrical energy output by the electromagnetic power generation unit and the frictional power generation unit, thereby improving the energy collection efficiency.

(3) The vibration energy harvesting device adopts an array design, which can adjust the elastic coefficient of the spring and the mass of the vibration pickup body, change the resonant frequency of the spring vibration pickup unit, match the vibration energy of different frequencies in the outside world, achieve the frequency extension effect in a multi-frequency vibration environment, broaden the working frequency band of the energy harvesting device, and improve the collection efficiency of vibration energy in the environment.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

FIG1 is a schematic structural diagram of a preferred embodiment of the present invention;

FIG2 is an internal side view of a preferred embodiment of the present invention;

FIG3 is a multi-modal schematic diagram of a preferred embodiment of the present invention;

FIG4 is a schematic structural diagram of the electromagnetic power generation unit and the vibration pickup body in a preferred embodiment of the present invention;

FIG5 is a schematic diagram of the exploded structure of a magnet unit and a vibration pickup body according to a preferred embodiment of the present invention;

FIG6 is a schematic structural diagram of the cooperation between the friction power generation unit and the vibration pickup body according to a preferred embodiment of the present invention;

FIG7 is a schematic structural diagram of a nano-friction generator according to a preferred embodiment of the present invention;

FIG8 is a diagram showing the extrusion and stretching state of the nano friction generator according to a preferred embodiment of the present invention;

FIG9 is a working principle diagram of a triboelectric generator according to a preferred embodiment of the present invention;

FIG10 is a schematic diagram of an arrayed frequency-adjustable spring vibration pickup unit according to a preferred embodiment of the present invention;

In the figure: 1, shell, 11, shell body, 12, ear, 121, mounting hole, 13, second inclined plane, 2, vibration energy collection unit, 3, spring vibration pickup unit, 31, vibration pickup body, 311, vibration pickup body, 3111, horizontal plane, 3112, first side, 3113, first inclined plane, 3114, vertical plane, 3115, third side, 3116, fourth side, 32, spring, 4, electromagnetic power generation unit, 41, magnet unit, 411, magnet, 42, coil, 5, friction power generation unit, 51, nano friction generator, 511, origami structure, 512, first friction material, 513, second friction material.

Embodiments of the present invention

In order to enable persons skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

Please refer to Figures 1 to 5. The embodiment of the present application discloses an arrayed electromagnetic-friction composite vibration energy collection device, including: a shell 1; a vibration energy collection mechanism, the vibration energy collection mechanism includes a plurality of vibration energy collection units 2, the plurality of vibration energy collection units 2 are arrayed in the shell 1, each vibration energy collection unit 2 includes a spring vibration pickup unit 3, an electromagnetic power generation unit 4 and a friction power generation unit 5; the spring vibration pickup unit 3 includes a vibration pickup body 31 and a plurality of springs 32, one end of each spring 32 is connected to the outer surface of the vibration pickup body 31, and the other end is connected to the inner surface of the shell 1; the electromagnetic power generation unit 4 includes a magnet unit 41 and a coil 42, the magnet unit 41 is arranged in the vibration pickup body 31, the magnet unit 41 includes two magnets 411 arranged opposite to each other in a vertical direction, the magnetic poles of the two magnets 411 repel each other, and the coil 42 is arranged outside the vibration pickup body 31 and connected to the inner surface of the shell 1; the friction power generation unit 5 is connected to the outer surface of the vibration pickup body 31. When the housing 1 is excited by external vibration, the spring vibration pickup unit 3 moves in the housing 1 under the action of gravity and inertia. The spring vibration pickup unit 3 has multimodal characteristics, and excitation in any direction can be converted into the movement of the vibration pickup body 31, so that the vibration pickup body 31 drives the two magnets 411 therein to move in the same direction, and the magnetic flux in the coil 42 changes, thereby generating an induced electromotive force, completing electromagnetic power generation; friction power generation is achieved through the friction power generation unit 5. The magnetic poles of the magnets 411 are in a vertical direction, and the two magnets 411 are arranged in a way that the magnetic poles repel each other to improve the efficiency of electromagnetic power generation. This device combines electromagnetic power generation with friction power generation to more efficiently convert the vibration energy in the external environment into electrical energy.

In this embodiment, the housing 1 includes two outer shells 11 symmetrically arranged in the vertical direction, and the outer surface of each outer shell 11 is provided with a plurality of ears 12, and each ear 12 is provided with a mounting hole 121. A stud passes through the mounting holes 121 of the two outer shells 11 and is then locked and fixed by screws. The housing 1 protects the vibration energy collection mechanism inside and transmits the vibration energy from the outside.

2 and 4 , the vibration pickup body 31 includes two vibration pickup bodies 311 spliced in the vertical direction, and two magnets 411 are respectively placed in the two vibration pickup bodies 311. The vibration pickup body 31 is assembled by splicing, and the two vibration pickup bodies 311 can be separated according to assembly requirements to facilitate the placement or removal of the magnets 411.

Specifically, the vibration pickup body 311 includes a horizontal surface 3111 , two first side surfaces 3112 disposed opposite to each other on the left and right sides, and two second side surfaces disposed opposite to each other on the front and back sides. The second side surfaces include a first inclined surface 3113 and a vertical surface 3114 connected to the first inclined surface 3113 .

The inner surface of the housing 1 is opposite to the first inclined surface 3113 to form a second inclined surface 13 . The second inclined surface 13 is arranged parallel to the first inclined surface 3113 . One end of the spring 32 is connected to the first inclined surface 3113 , and the other end is connected to the second inclined surface 13 .

In this embodiment, each spring vibration pickup unit 3 is provided with four springs 32 to form a four-spring vibration pickup unit. The angle between the first inclined surface 3113 and the horizontal plane is 45°. The angle between the center lines of adjacent springs 32 of the spring vibration pickup unit 3 is 90°.

Figure 3 (a) to Figure 3 (f) are multi-modal schematic diagrams of the spring vibration pickup unit 3. The modal analysis is performed by using COMSOL software to perform finite element modeling of the spring vibration pickup unit 3. The four-spring vibration pickup unit has multi-degree-of-freedom multi-modal vibration characteristics, which can convert the multi-degree-of-freedom multi-frequency band vibration energy into the movement of the vibration pickup body itself, and then convert it into electrical energy output by the electromagnetic power generation unit 4 and the friction power generation unit 5.

The spring 32 is fixedly connected to the vibration pickup body 31 and the housing 1 by screws or adhesives. Preferably, the coil 42 is embedded in the inner surface of the housing 1 by friction force to improve the stability of the coil 42.

Please refer to FIG. 10 , the two first side surfaces 3112 and the two vertical surfaces 3114 of the two vibration pickup bodies 311 are respectively spliced into a third side surface 3115 and a fourth side surface 3116 , and the friction power generation unit 5 is connected to the horizontal surface 3111 , the third side surface 3115 , and the fourth side surface 3116 .

Please refer to Figures 1, 6 and 7. The friction power generation unit 5 includes a plurality of nano friction generators 51. The nano friction generators 51 include an origami structure 511, a plurality of first friction materials 512 and a plurality of second friction materials 513 disposed on the origami structure 511. The first friction materials 512 and the second friction materials 513 are disposed opposite to each other.

In order to prevent the multiple nano-friction generators 51 from affecting each other's movement in their respective directions, one end of the origami structure 511 is preferably connected to the outer surface of the vibration pickup body 31 , and a gap is provided between the other end and the inner surface of the housing 1 .

As shown in Figures 8 and 9, it is a schematic diagram of the structure and principle of the friction power generation unit 5. Preferably, the origami structure 511 is made of polyimide Pi, the first friction material 512 is made of FEP that is easy to obtain electrons, and the second friction material 513 is made of Cu that is easy to lose electrons. The first friction material 512 and the second friction material 513 are respectively covered on the opposite paper surfaces of the origami structure 511. Vibration excitation will cause the origami structure 511 of the nano friction generator 51 in each direction to be squeezed and stretched. The first friction material 512 and the second friction material 513 with different electron gain and loss capabilities contact and separate, and under the joint action of electrostatic induction and friction electrification, electrical energy output is generated to complete friction power generation.

In this embodiment, each nano-friction generator 51 is distributed in six different directions of the vibration pickup body 31. The vibration pickup body 31 converts the multi-directional and multi-band vibration energy in the environment into a squeezing movement of the origami structure 511 in various directions, thereby improving the power generation efficiency.

Since the resonant frequency of the spring vibration pickup unit 3 is determined by the mass of the vibration pickup body 31 and the elastic coefficient of the spring 32. The greater the mass of the vibration pickup body 31, the smaller the resonant frequency of the spring vibration pickup unit 3. The greater the elastic coefficient of the spring 32, the greater the resonant frequency of the spring vibration pickup unit 3. The device selects springs 32 with different elastic coefficients, as shown in Figure 10. Figure 10 (a) selects springs 32 with large elastic coefficients, so that the resonant frequency of the spring vibration pickup unit 3 is high frequency, Figure 10 (b) selects springs 32 with medium elastic coefficients, so that the resonant frequency of the spring vibration pickup unit 3 is medium frequency, and Figure 10 (c) selects springs 32 with small elastic coefficients, so that the resonant frequency of the spring vibration pickup unit 3 is low frequency, so that the resonant frequency of the spring vibration pickup unit 3 is distributed from low frequency to high frequency, forming an arrayed adjustable frequency vibration energy collection device, thereby broadening the working frequency band of the device and improving the energy collection efficiency.

When the present invention is in use, when the housing 1 is excited by external vibration, the vibration pickup body 31 moves in the housing 1 under the action of gravity and inertia, converting the external multi-directional and multi-band vibration energy into the movement of the vibration pickup body 31. The movement of the magnet 411 in the vibration pickup body 31 causes the magnetic flux in the coil 42 to change, and the coil 42 generates an induced electromotive force due to the electromagnetic induction effect and outputs electrical energy. The relative size and position of the magnet 411 and the coil 42 can be adjusted to maximize the change in magnetic flux caused by the moving magnet 411 in the coil 42 during operation; the wire diameter and the number of winding turns in the coil 42 can be adjusted to optimize electromagnetic power generation and achieve better output effects.

The spring vibration pickup unit 3 is a four-spring vibration pickup unit with multi-degree-of-freedom and multi-modal vibration characteristics. The vibration energy in multiple directions and frequency bands can be converted into the movement of the vibration pickup body 31 in respective directions. On the basis of the electromagnetic power generation unit 4, multiple nano friction generators 51 are introduced and arranged in various directions of the vibration pickup body 31. Excitation in any direction can be converted into the extrusion movement of the origami structure 511 in various directions. Due to the triboelectric effect and the principle of electrostatic induction, an electric potential difference is formed between different friction materials to achieve electrical energy output. When the spring vibration pickup unit 3 is excited by the vibration of a certain degree of freedom in a certain frequency band and the motion response amplitude is small, resulting in low electromagnetic power generation efficiency, the friction power generation unit 5 has an advantage in collecting high-entropy low-frequency energy and can be used as a supplement when the output of the electromagnetic power generation unit 4 is insufficient. Therefore, the device adopts the electromagnetic-friction composite ring energy principle, which can more efficiently convert the vibration energy in the environment into electrical energy output.

This device adopts an array design, and the multiple spring vibration pickup units 3 inside can convert external vibration energy into kinetic energy of the vibration pickup body 31. When the natural frequency of the spring vibration pickup unit 3 is the same as the external vibration frequency, the power generation efficiency is the highest. When the external vibration frequency deviates from the natural frequency of the vibration pickup body 31, the power generation efficiency drops sharply. Since the natural frequency of the spring vibration pickup unit 3 is affected by the elastic coefficient of the spring 32 and the mass of the vibration pickup body 31, an array design is adopted to cover the multi-frequency vibration energy in the environment through multiple spring vibration pickup units 3 with different natural frequencies, thereby improving the power generation efficiency of the device.

It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims (10)

An arrayed electromagnetic-friction composite vibration energy collection device, characterized in that it comprises: shell; A vibration energy collection mechanism, the vibration energy collection mechanism comprising a plurality of vibration energy collection units, the plurality of vibration energy collection units being arranged in an array in the housing, each of the vibration energy collection units comprising a spring vibration pickup unit, an electromagnetic power generation unit and a friction power generation unit; The spring vibration pickup unit comprises a vibration pickup body and a plurality of springs, one end of each of the springs being connected to the outer surface of the vibration pickup body and the other end being connected to the inner surface of the housing; The electromagnetic power generation unit includes a magnet unit and a coil. The magnet unit is arranged in the vibration pickup body. The magnet unit includes two magnets arranged opposite to each other in a vertical direction. The magnetic poles of the two magnets repel each other. The coil is arranged outside the vibration pickup body and connected to the inner surface of the shell. The friction power generation unit is connected to the outer surface of the vibration pickup body. According to the arrayed electromagnetic-friction composite vibration energy collection device according to claim 1, it is characterized in that the vibration pickup body includes two vibration pickup bodies spliced in the vertical direction, and the two magnets are respectively placed in the two vibration pickup bodies. The arrayed electromagnetic-friction composite vibration energy collection device according to claim 2 is characterized in that the vibration pickup body includes a horizontal plane, two first side surfaces arranged opposite to each other on the left and right, and two second side surfaces arranged opposite to each other on the front and back, and the second side surfaces include a first inclined plane and a vertical plane connected to the first inclined plane. According to the arrayed electromagnetic-friction composite vibration energy collection device according to claim 3, it is characterized in that the inner surface of the shell is arranged to form a second inclined surface opposite to the first inclined surface, the second inclined surface is arranged parallel to the first inclined surface, one end of the spring is connected to the first inclined surface, and the other end is connected to the second inclined surface. The arrayed electromagnetic-friction composite vibration energy collection device according to claim 4 is characterized in that the angle between the first inclined plane and the horizontal plane is 45°. According to the arrayed electromagnetic-friction composite vibration energy collection device of claim 4, it is characterized in that the angle between the center lines of adjacent springs of the spring vibration pickup unit is 90°. According to the arrayed electromagnetic-friction composite vibration energy collection device according to claim 1, it is characterized in that the magnet is rectangular. According to the arrayed electromagnetic-friction composite vibration energy collection device according to claim 3, it is characterized in that the two first side surfaces and the two vertical surfaces of the two vibration pickup bodies are respectively spliced into a third side surface and a fourth side surface, and the friction power generation unit is connected to the horizontal plane, the third side surface, and the fourth side surface. According to the arrayed electromagnetic-friction composite vibration energy collection device according to claim 1 or 8, it is characterized in that the friction power generation unit includes a plurality of nano friction generators, and the nano friction generators include an origami structure, a plurality of first friction materials and a plurality of second friction materials arranged on the origami structure, and the first friction material and the second friction material are arranged opposite to each other. According to the arrayed electromagnetic-friction composite vibration energy collection device according to claim 9, it is characterized in that one end of the origami structure is connected to the outer surface of the vibration pickup body, and there is a gap between the other end and the inner surface of the outer shell.