CN111049417B

CN111049417B - Friction generator

Info

Publication number: CN111049417B
Application number: CN201811194254.6A
Authority: CN
Inventors: 王杰; 程萍; 郭恒宇; 文震; 其他发明人请求不公开姓名
Original assignee: Beijing Institute of Nanoenergy and Nanosystems
Current assignee: Beijing Institute of Nanoenergy and Nanosystems
Priority date: 2018-10-12
Filing date: 2018-10-12
Publication date: 2022-09-16
Anticipated expiration: 2038-10-12
Also published as: CN111049417A

Abstract

The invention discloses a friction generator, comprising: a housing having an interior cavity; the friction layer is arranged on the inner wall of the shell; the movable body is positioned in the inner cavity of the shell, and a cavity of the movable body is provided with liquid; wherein the movable body can change the contact area with the friction layer under the action of external force and the liquid. The movable body in the friction generator provided by the invention can change the contact area with the electrode layer under the action of the liquid in the movable body, namely, the traditional hard point contact is changed into flexible surface contact, so that the output performance of the generator is improved.

Description

Friction generator

Technical Field

The invention relates to the field of nano new energy, in particular to a friction generator.

Background

Since the friction generator was proposed, it was rapidly developed, and the friction generator does not require heavy materials and equipment and can be manufactured using simple and lightweight materials, compared to the conventional electromagnetic generator. And when the device is used for collecting ocean energy, the device does not affect marine life and passing ships due to the existence of electromagnets like a traditional electromagnetic generator.

The existing friction generators for collecting ocean energy are mainly of three types: the first is to generate electricity by friction of a fixed liquid interface, but a large amount of ions exist in seawater, so that the seawater has strong conductivity, most of charges generated by friction can be transferred away, and the output of a generator is weakened; secondly, a friction and electromagnetic hybrid generator is utilized, the method for collecting ocean energy solves the problem of sealing of a friction nano generator, but the introduction of a magnet can affect marine organisms and passing ships; the third is a friction generator by sea wave impact, which generates electric charge by adopting a solid electrode and a contact and friction form between the solid electrodes, and the generator generally adopts a ball type structure which is easy to integrate in a large area.

The contact form of the existing spherical generator is hard point contact, the contact area is relatively too small, the transferred charge quantity is relatively small, and therefore the output performance of the generator is not ideal.

Disclosure of Invention

In view of the above, in order to overcome at least one aspect of the above problems, an embodiment of the present invention provides a friction generator, including: a housing having an interior cavity; the friction layer is arranged on the inner wall of the shell; the movable body is positioned in the inner cavity of the shell, and a liquid is arranged in a cavity of the movable body; wherein the movable body can change the contact area with the friction layer under the action of external force and the liquid.

Further, the volume of the liquid is at least 50% of the volume of the cavity of the movable body.

Further, the liquid is one of water, mercury or an aqueous solvent.

Further, the contact area is 1/5-1/3 of the surface area of the movable body.

Further, the friction layer comprises a first friction layer and a second friction layer, and the first friction layer and the second friction layer are arranged in an insulating mode.

Further, the shell is made of at least one waterproof material.

Further, the movable body is made of flexible materials.

Further, the thickness of the movable body is between 0.2mm and 24 mm.

Further, the friction layer includes:

the electrode layer is arranged on the inner wall of the shell;

a dielectric layer disposed on the electrode layer such that the electrode layer is located between an inner wall of the case and the dielectric layer;

wherein the movable body is capable of increasing a contact area with the dielectric layer by the liquid.

Further, the electrode layer includes a first electrode layer and a second electrode layer, and the first electrode layer and the second electrode layer are arranged in an insulating manner.

Further, the movable body is made of a flexible material with strong electronegativity.

Further, the movable body is made of silica gel.

Compared with the prior art, the invention has one of the following advantages:

1. the movable body of the generator is made of flexible materials, so that the contact area between the movable body and the electrode layer can be increased, namely the traditional hard point contact is changed into flexible surface contact, and the output performance of the generator is improved;

2. the shell is made of waterproof materials, so that the generator can work in an underwater environment;

3. the thickness of the movable body can be changed according to different specific environments of different water areas, so that the optimal output of the generator is realized;

4. the friction generator provided by the embodiment of the invention can have good sealing performance without a large number of magnets, and has ideal output performance.

Drawings

Other objects and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings, and may assist in a comprehensive understanding of the invention.

Fig. 1 is a schematic structural diagram of a friction generator according to an embodiment of the present invention;

FIG. 2 is a front view of four movable bodies of different thicknesses according to an embodiment of the present invention;

FIG. 3 is a graph comparing the maximum amount of transferred charge that can be output by the triboelectric generator of FIG. 1 at different moving distances when using movable bodies of different thicknesses;

FIG. 4 is a graph comparing the maximum amount of transferred charge that can be output by the triboelectric generator of FIG. 1 at different frequencies of motion when using movable bodies of different thicknesses;

FIG. 5 is a graph comparing the maximum amount of transferred charge output by a generator according to an embodiment of the present invention and a conventional solid movable body made of PTFE at different moving distances;

FIG. 6 is a diagram comparing a generator according to an embodiment of the present invention with a conventional solid movable body made of PTFE while charging the same capacitor;

FIG. 7 is a schematic diagram of a generator according to an embodiment of the present invention operating in an actual water environment;

FIG. 8 is a schematic diagram of the power generation principle of the friction power generator of FIG. 1;

fig. 9 is a schematic diagram of the power generation principle of another friction power generator provided by the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present invention. It should be apparent that the described embodiment is one embodiment of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention without any inventive step, are within the scope of protection of the invention.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs.

Some embodiments of the invention are described in detail below with reference to the accompanying drawings. The embodiments described below and the features of the embodiments can be combined with each other without conflict.

As shown in fig. 1, an embodiment of the present invention provides a friction generator 10, which may include a housing 100, a friction layer 200 disposed on an inner wall of the housing 100, and a movable body 301 located in a cavity of the housing 100, and a substance capable of changing an outer shape of the movable body 301 is further contained inside the movable body 301. In this way, the contact between the movable body 301 and the friction layer 200 is surface contact, which increases the contact area between the movable body 301 and the friction layer 200, so that after the movable body 301 rubs against the friction layer 200 under the action of external force, more charges can be generated, that is, external mechanical energy is converted into mechanical energy of the friction generator 10, and then the mechanical energy is converted into electric energy through the structure of the friction generator 10 itself.

The housing 100 shown in fig. 1 may be made of an acrylic material, so that the friction generator 10 provided in this embodiment may be used to collect kinetic energy of water due to the waterproof property of the acrylic material itself. For example, placing the friction generator 10 at the surface of the sea collects kinetic energy generated as the seawater flows. Of course, in other embodiments, the housing 100 may be made of other waterproof materials, or a combination of waterproof materials.

In the present embodiment, the housing 100 may have a closed spherical structure, but may have another structure, for example, a cylindrical structure. And the size and thickness of the housing 100 can be set according to different requirements, for example, the diameter of the housing 100 can be 70 mm, and the thickness can be 2 mm. It is understood that the diameter and thickness of the housing 100 may be larger or smaller to meet the requirements of different environments.

As shown in fig. 1, the friction layer 200 disposed on the inner wall of the casing 100 may include a first friction layer 201 and a second friction layer 202. Both the first friction layer 201 and the second friction layer 202 may extend along the inner wall of the casing 100, and the first friction layer 201 and the second friction layer 202 are insulated by a gap 400, and preferably, the first friction layer 201 and the second friction layer 202 have the same extending surface area. It is of course also possible to provide an insulating material in the gap 400 to insulate between the first friction layer 201 and the second friction layer 202. In this way, when the charge generated by the friction generator 10 is used to power a load or for storage via the conductors, an alternating current can be formed in the circuit without short-circuiting the circuit.

In this embodiment, the first friction layer 201 and the second friction layer 202 may be obtained by attaching two smooth metal sheets to the inner wall of the housing, for example, two smooth copper sheets with a thickness of 50 micrometers may be attached to the inner wall of the housing, and it should be noted that, when attaching the two copper sheets, a gap 400 needs to be spaced between the two copper sheets to satisfy the insulation setting between the first friction layer 201 and the second friction layer 202, and at this time, the two copper sheets may cover almost the entire inner wall of the housing but not completely cover the entire inner wall. It is understood that other metals may be used to form the friction layer 200, such as a smooth sheet of metal.

In this embodiment, the movable body 301 may be a spherical structure, for example, a small sphere, which may be made of a flexible material such as silicone, or other materials with high flexibility and electronegativity, and the volume of the movable body may also be enlarged or reduced according to actual requirements. And the movable body 301 made of flexible material can change the shape structure easily, so that when the liquid 302 is filled in the movable body 301, the contact area between the movable body 301 and the friction layer 200 can be increased under the action of external force and the liquid 302, that is, the traditional hard point contact is changed into flexible surface contact, and more charges can be generated. Moreover, when the inventor tests two different contact modes, the generator adopting the flexible surface contact mode can generate the transfer charge amount of about 500 nanobins at the highest frequency, and the value is 10 times that of the generator adopting the hard point contact mode. And the open-circuit voltage and the short-circuit current of the generator can be improved in the same proportion by adopting the contact of the flexible surface, and the output performance of the generator is obviously superior to that of the traditional generator adopting hard point contact under the frequency of 2 Hz, namely, the generator adopting Polytetrafluoroethylene (PTFE) as a friction material.

In this embodiment, the liquid 302 may be water, and the volume of the water injected into the movable body 301 is at least 50% of the volume of the movable body 301, so that when the movable body 301 is reshaped, the outer surface of the movable body 301 has a larger contact area with the friction layer 200, and the generated electric charges are more. Of course, the liquid 302 is not limited to only water, and other liquids 302 capable of changing the shape of the movable body 301 may be used, such as an aqueous solvent, mercury, and the like, and the aqueous solvent may be saline, and the like, as long as the movable body 301 can change the shape by its action and can increase the inertia of the movement.

Further, according to the study of the inventors, it was found that the movable body 301 has a different thickness and a different degree of change in the external shape by injecting the same volume of the liquid 302. The thickness of the movable body 301 may be between 0.2mm and 24mm, and may be, for example, 0.2mm, 0.3mm, 1mm, 2mm, 10mm, 20mm, or 24 mm. The thickness of the movable body 301 may be increased or decreased according to various environments to meet actual demands.

Specifically, the movable body 301 is placed on a plane, and the diameter of the base surface of the movable body with respect to the plane may be not less than 0.4 cm and may be 4.8 cm at most under the action of the internal liquid 302. Further, according to the research of the inventors, it was found that the contact area of the movable body 301 with the friction layer 200 by the external force and the liquid is about 1/5-1/3 of the surface area of the movable body 301.

Fig. 8 shows a schematic diagram of the power generation principle of the friction power generator provided in the present embodiment. As shown in the figure, the movable body 301 reciprocally rolls in the cavity under the action of an external force, and the surface of the movable body 301 rubs against the surface of the friction layer 200, so that triboelectricity of different electric properties is respectively generated on the surfaces of the movable body 301 and the friction layer 200, and an alternating current is generated in the load 500. Specifically, as shown in fig. 8(i), when the movable body 301 rubs against only the first friction-friction layer 201, the surface of the movable body 301 is negatively charged by friction, and the surface of the first friction layer 201 is positively charged by friction. As shown in fig. 8(ii), when the movable body 301 moves toward the second friction layer 202, since the amount of charges generated by the friction between the surface of the first friction layer 201 and the surface of the second friction layer 202 is different and the positive charge generated by the second friction layer 202 is small, the two frictions generate different potentials. Under the action of the electric field, a current I flowing from the first friction layer 201 to the second friction layer 202 is formed in the load 500. When the movable body moves to be biased toward the second friction layer 202, a current I flowing from the second friction layer 202 to the first friction layer 201 is formed in the load 500. As shown in fig. 8(iii), when the movable body 301 continues to move to the top of the second friction layer 202 by the external force, the movable body 301 starts to move in the opposite direction, and as shown in fig. 8(iv), a current I flowing from the second friction layer 202 to the first friction layer 201 is formed in the load 500 by the electric field due to the large positive charge generated in the second friction layer 202. When the movable body moves to be biased toward the first friction layer 201, a current I flowing from the first friction layer 201 to the second friction layer 202 is formed in the load 500. When the movable body 301 continues to move by the external force, it moves to the position shown in fig. 8(i) again. The movable body 301 is reciprocated by an external force, and a continuous alternating current is formed in the load 500.

The effect of the four different thicknesses of the movable body 301 on the output performance of the generator will be described in detail below with reference to fig. 2 to 6.

Referring to fig. 2, four kinds of movable bodies 301 having different thicknesses and the same thickness are numbered as a # 1 movable body having a thickness of 0.28mm, a # 2 movable body having a thickness of 0.42mm, a # 3 movable body having a thickness of 1.12mm and a # 4 movable body having a thickness of 24mm, and placed on the same plane, and after the same volume of liquid 302 is injected into the respective bodies, the diameter of the contact surface between the # 1 movable body and the plane is 4.8 cm, the contact area is about 1/3 of the surface area of the movable body 301, the diameter of the contact surface between the # 2 movable body and the plane is 3.9 cm, the contact area is about 1/4 of the surface area of the movable body 301, the diameter of the contact surface between the # 3 movable body 301 and the plane is 3.0 cm, the contact area is about 1/5 of the surface area of the movable body 301, the diameter of the contact surface between the # 4 movable body 301 and the plane is 0.4 cm, and the contact is point contact, in this way, when the volume of the liquid 302 injected inside the movable body 301 is constant, the contact area of the movable body 301 and the friction layer 200 can be increased or decreased by changing the thickness of the movable body 301. And the inventors have also found that the output performance of the generator using the # 1 movable body 301, i.e., the movable body 301 having a relatively thin thickness, is the best when the generator is in a high-frequency moving state, and the output performance of the generator using the # 2 movable body 301 is relatively good when the moving frequency of the generator is low.

Fig. 3 shows the maximum amount of transferred charge that can be output by the friction generator 10 provided by the embodiment of the present invention when different numbers of movable bodies 301 are used and different movement distances are used at the same movement frequency. As can be seen from the figure, the maximum amount of transferred charge that can be generated increases with the relative movement distance regardless of the thickness of the generator, but the generators using the # 1 movable body 301 and the # 2 movable body 301 generate a relatively high maximum amount of transferred charge with the same relative movement distance as the generators using the # 3 movable body 301 and the # 4 movable body 301.

Fig. 4 shows the maximum amount of transferred charge that can be output by the friction generator 10 provided by the embodiment of the present invention when different numbers of movable bodies 301 are used and different movement frequencies are used at the same displacement distance. As can be seen from the figure, the output performance of the generator using the # 1 movable body 301 is the best at a movement frequency of 2 hz, which is significantly higher than the output of the generator using the other numbers of movable bodies 301, i.e., the output performance of the generator is the better as the thickness of the movable body 301 becomes thinner at a frequency of 2 hz. Also, the generator using the # 2 movable body 301 has a better output as the frequency decreases.

Fig. 5 shows a comparison of the maximum amount of transferred charge output of the generator of the present invention with a conventional solid movable body 301 made of Polytetrafluoroethylene (PTFE) at the same moving frequency and different moving distances. As can be seen from the figure, the output of the generator using the movable body 301 provided by the embodiment of the present invention is about 2 times that of the generator using the solid movable body 301 made of the conventional teflon.

Fig. 6 shows a comparison of the generator of the present invention with a conventional solid movable body 301 made of Polytetrafluoroethylene (PTFE) to charge the same capacitor (2.2 microfarads) at the same frequency of motion and different distances of motion. As can be seen from the figure, the generator using the # 2 movable body 301 provided by the embodiment of the present invention charges significantly faster than the generator using the solid movable body 301 made of the conventional Polytetrafluoroethylene (PTFE).

Fig. 7 is a photograph showing the operation of the generator provided by the embodiment of the present invention in an actual water environment. It can be seen that the friction generator 10 of the movable body 301 made of flexible silica gel can light more than 20 LED lamps in actual underwater environment.

In another embodiment, the friction layer may further include an electrode layer disposed on the inner wall of the case and a dielectric layer disposed on the electrode layer. Like this, when the inside at the activity body is held and is had the material that can change the activity body appearance, the contact of activity body and dielectric layer is face contact promptly, has increased the area of contact of activity body and dielectric layer to make the activity body take place the friction back with the dielectric layer under the effect of external force, can produce more electric charges, be about to outside mechanical energy converts the mechanical energy of friction generator into, and the structure of rethread friction generator itself converts into the electric energy.

And a dielectric layer is attached to the electrode layer, so that the electrode layer is positioned between the dielectric layer and the shell, the dielectric layer can be made of polytetrafluoroethylene, the internal movable body can be made of a flexible material with weak electronegativity, or the flexible material with strong electronegativity can be subjected to surface modification to further make the surface of the flexible material with strong electronegativity positively charged to obtain the movable body, or the movable body is made of silica gel.

In this embodiment, the electrode layer may include a first electrode layer and a second electrode layer, and the first electrode layer and the second electrode layer are provided to be insulated. Since the electrode layers are located between the dielectric layer and the housing, the first electrode layer and the second electrode layer are thus also located between the dielectric layer and the housing. And the movable body in the cavity is in contact with the dielectric layer, under the action of external force, the movable body can roll in the cavity in a reciprocating mode, the surface of the movable body and the surface of the dielectric layer can rub, triboelectricity can be generated on the surfaces of the movable body and the dielectric layer respectively, free charges can be induced and generated in the first electrode layer and the second electrode layer, and at the moment, when the two electrode layers are connected with a load, alternating current can be generated in the load.

The friction generator provided in this embodiment is the same as the friction generator 10 provided in the above embodiments in other components and manufacturing materials, such as the thickness of the movable body, the manufacturing material of the housing, and the like, which are not described herein again.

Fig. 9 shows a power generation principle diagram of the friction power generator provided in the present embodiment. As shown, the dielectric layer 600 is located between the electrode layers and the movable body 301, and when the movable body 301 repeatedly moves under an external force and rubs against the dielectric layer 600, induced charges occur on the two electrodes, which generates a current in the load 400 connected to the first electrode layer 2201 and the second electrode layer 2202. As shown in fig. 9(i), when the movable body 301 comes into contact with the upper portion of the first electrode layer 2201, no current is generated in the load 400, and the load is in an initial state. As shown in fig. 9(ii), when the movable body 301 moves relatively over the first electrode layer 2201 and the second electrode layer 2202, a current is formed in the load 400 by an electric field. As shown in fig. 9(iii), when the movable body 301 moves above the second electrode layer 2202, the movable body 301 moves in the opposite direction to the first electrode layer 2201 again by an external force. The movable body 301 is reciprocated in a cycle by an external force, and a continuous alternating current is generated in the load 400.

Compared with the prior art, the generator provided by the embodiment of the invention adopts the movable body made of the flexible material, so that the contact area between the movable body and the electrode layer can be increased, namely the traditional hard point contact is changed into the flexible surface contact, the output performance of the generator is improved, and the shell is made of the waterproof material, so that the generator can work in water environment, such as ocean, and the thickness of the movable body can be changed according to different specific ocean environments, so as to realize the optimal output performance.

It should also be noted that, in case of conflict, the embodiments and features of the embodiments of the present invention may be combined with each other to obtain new embodiments.

Finally, it should be noted that the above embodiments are only intended to illustrate the technical solutions of the present invention and not to limit the same, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A friction generator comprising:

a housing having an interior cavity;

the friction layer is arranged on the inner wall of the shell; and

the movable body is positioned in the inner cavity of the shell, and a cavity of the movable body is provided with liquid, wherein the volume of the liquid is at least 50% of the volume of the cavity of the movable body;

wherein the movable body can change the contact area with the friction layer under the action of external force and the liquid; the contact area is 1/5-1/3 of the surface area of the movable body.

2. A triboelectric generator according to claim 1, wherein the liquid is one of water, mercury or an aqueous solvent.

3. A triboelectric generator according to claim 1, wherein the friction layer comprises a first friction layer and a second friction layer, the first and second friction layers being arranged in insulation.

4. A triboelectric generator according to claim 1, wherein the housing is made of at least one waterproof material.

5. A triboelectric generator according to claim 1, wherein the movable body is made of a flexible material.

6. A triboelectric generator according to any of claims 1 or 3 or 4, wherein the thickness of the movable body is between 0.2mm-24 mm.

7. A triboelectric generator according to claim 1, wherein the friction layer comprises:

the electrode layer is arranged on the inner wall of the shell;

wherein the movable body is capable of changing a contact area with the dielectric layer by the liquid.

8. A triboelectric generator according to claim 7, wherein the electrode layers comprise a first electrode layer and a second electrode layer, the first and second electrode layers being arranged in isolation.

9. A triboelectric generator according to claim 1, characterized in that the movable body is made of a flexible and highly electronegative material.

10. A triboelectric generator according to any of claims 7 to 9, wherein the movable body is made of silicone.