Rotating energy harvester and generator

Abstract

A rotary energy harvesting device and a generator, the rotary energy harvesting device comprises a rotating shaft, a cam, a moving component, a functional component, a dielectric elastomer, a first flexible electrode and a second flexible electrode, the first flexible electrode and the second flexible electrode are arranged on the dielectric elastomer and form a capacitor, the functional component is electrically connected to the first flexible electrode and the second flexible electrode, the moving component is connected to the cam, the moving component is connected to the first flexible electrode and / or the dielectric elastomer, the rotating shaft is connected to the cam and is used to drive the cam to rotate, so that the moving component moves back and forth, so that the dielectric elastomer, the first flexible electrode and the second flexible electrode are periodically deformed, and the capacitance of the capacitor changes periodically to generate electrical energy. The rotary motion of the cam is converted into reciprocating linear motion by the moving component, so that the capacitor is periodically deformed, and the capacitance of the capacitor changes periodically to generate electrical energy, thereby realizing the collection of the energy of the rotary motion.

Description

Technical Field

[0001] The present invention belongs to the technical field of power generation, and in particular relates to a rotary energy harvesting device and a generator having the rotary energy harvesting device. Background Art

[0002] Dielectric elastomer is a dielectric film material with elastic deformation ability. It has the advantages of high energy density, large deformation range, low price and high electromechanical conversion efficiency. Flexible electrodes are coated on the upper and lower surfaces of the dielectric elastomer film to prepare elastic variable capacitors. Under voltage input conditions, external excitation causes the film to deform and the capacitance to change continuously, thereby realizing the conversion of mechanical energy into electrical energy.

[0003] The current dielectric elastomer energy harvesting devices have few application scenarios and are only suitable for energy collection from vibration or linear motion, but not for energy collection from rotational motion. Therefore, how to use dielectric elastomers to provide an energy harvesting device that can collect rotational motion has become the key. Summary of the invention

[0004] The object of the present invention is to provide a rotary energy harvesting device capable of collecting the energy of rotary motion by utilizing a capacitor formed by a dielectric elastomer.

[0005] To achieve the purpose of the present invention, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides a rotary energy harvesting device, which includes a rotating shaft, a cam, a moving component, a functional component, a dielectric elastomer, a first flexible electrode and a second flexible electrode, wherein the first flexible electrode and the second flexible electrode are arranged on the dielectric elastomer and form a capacitor, the functional component is electrically connected to the first flexible electrode and the second flexible electrode, the moving component is connected to the cam, the moving component is connected to the first flexible electrode and / or the dielectric elastomer, the rotating shaft is connected to the cam and is used to drive the cam to rotate so that the moving component moves back and forth, so that the dielectric elastomer, the first flexible electrode and the second flexible electrode undergo periodic deformation, and the capacitance of the capacitor undergoes periodic changes to generate electrical energy.

[0007] In one embodiment, the functional component includes a coil and a magnetic component, the first flexible electrode and the second flexible electrode are both electrically connected to the coil, the coil is sleeved on the rotating shaft and rotates with the rotating shaft, and the magnetic component is arranged on the side of the coil facing away from the rotating shaft and has a spacing distance from the coil; when the rotating shaft drives the coil to rotate, the coil cuts the magnetic field generated by the magnetic component to generate an induced electromotive force, so that there is a voltage between the first flexible electrode and the second flexible electrode.

[0008] In one embodiment, the rotary energy harvesting device further includes a shell, the cam and the coil are both located in the shell, and the magnetic member is disposed on an inner wall of the shell and on opposite sides of the coil.

[0009] In one embodiment, the rotary energy harvesting device also includes an annular clamp, the dielectric elastomer is arranged outside the shell, the annular clamp is arranged at the edge of the second flexible electrode of the dielectric elastomer, and the second flexible electrode, the dielectric elastomer and the first flexible electrode are fixed to the shell.

[0010] In one embodiment, the moving component includes a first fixing member arranged between the shell and the first flexible electrode, the first fixing member includes a connecting surface connected to the first flexible electrode, the connecting surface includes a middle part and an edge part surrounding the middle part; when the dielectric elastomer, the first flexible electrode and the second flexible electrode are not deformed, the distance between the edge part and the first flexible electrode is greater than the distance between the middle part and the first flexible electrode.

[0011] In one embodiment, the edge portion is a curved surface.

[0012] In one embodiment, the motion component further includes a second fixing member and a third fixing member, wherein the second fixing member is disposed on the second flexible electrode, and one end of the third fixing member is connected to the second fixing member, and the other end passes through the dielectric elastomer and is connected to the first fixing member.

[0013] In one embodiment, the motion assembly includes a push rod and an elastic member, the push rod is slidably connected to the shell, and the elastic member is arranged between the push rod and the shell, so that when the push rod moves away from the cam, it is subjected to the elastic force generated by the compression of the elastic member.

[0014] In one embodiment, the motion assembly further includes a roller and a roller bracket, wherein the roller bracket is connected to the push rod, and the roller is disposed on the roller bracket and is rollingly connected to the cam.

[0015] In a second aspect, the present invention further provides a generator, comprising a rotating part and the rotary energy harvesting device described in any one embodiment of the first aspect, wherein the rotating part is arranged on the rotating shaft of the rotary energy harvesting device, and the rotating part is used to convert the external medium flow into torque to drive the rotating shaft to rotate.

[0016] By setting a first flexible electrode and a second flexible electrode on a dielectric elastomer to form a capacitor, the motion component converts the rotational motion of the cam into reciprocating linear motion, so that the dielectric elastomer, the first flexible electrode and the second flexible electrode undergo periodic deformation, and the capacitance of the capacitor undergoes periodic changes to generate electrical energy, thereby realizing the collection of energy from the rotational motion. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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 will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A front view schematic diagram of the structure of the rotary energy harvesting device provided by the present invention;

[0019] Figure 2 for Figure 1 A schematic cross-sectional structural diagram of a rotary energy harvesting device in a front view direction;

[0020] Figure 3 for Figure 1 A schematic diagram of a cross-sectional structure of a rotary energy harvester in a top-down direction;

[0021] Figure 4 for Figure 2 A front view structural schematic diagram of the first fixing member. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] See also Figure 1 and Figure 2The embodiment of the present invention provides a rotary energy harvesting device 100, which is used to convert rotary excitation into electrical energy, wherein the rotary excitation can be provided by energy in the form of tidal energy, wind energy, water energy, etc. The rotary energy harvesting device 100 includes a rotating shaft 10, a cam 20, a moving component 30, a dielectric elastomer 40, a first flexible electrode 50, a second flexible electrode 60, and a functional component 70. The first flexible electrode 50 and the second flexible electrode 60 are arranged on the dielectric elastomer 40 and form a capacitor. The functional component 70 is electrically connected to the first flexible electrode 50 and the second flexible electrode 60. The moving component 30 is connected to the cam 20, and the moving component 30 is connected to the first flexible electrode 50 and / or the dielectric elastomer 40. The rotating shaft 10 is connected to the cam 20 and is used to drive the cam 20 to rotate, so that the moving component 30 moves back and forth, so that the dielectric elastomer 40, the first flexible electrode 50 and the second flexible electrode 60 are periodically deformed, and the capacitance of the capacitor changes periodically to generate electrical energy.

[0024] Specifically, the dielectric elastomer 40 can be selected from materials such as silicone rubber, polyurethane, acrylic acid, and composite materials. In order to facilitate deformation, the dielectric elastomer 40 is in the form of a thin film. A flexible electrode material is coated on one side of the dielectric elastomer 40 to form a first flexible electrode 50, and a flexible electrode material is coated on the other side of the dielectric elastomer 40 to form a second flexible electrode 60 facing away from the first flexible electrode 50. In this way, since the dielectric elastomer 40 has a high dielectric constant, the dielectric elastomer 40 and the first flexible electrode 50 and the second flexible electrode 60 on both sides thereof form a capacitor with a large capacitance and variable capacitance. The rotating shaft 10 is used to connect with a rotating member such as a rotating blade to transmit the rotational excitation to the cam 20 and drive the cam 20 to rotate. The outer periphery of the cam 20 has a designed contour, so that the moving component 30 reciprocates along the contour of the outer periphery of the cam 20 with a certain regularity (towards the capacitor / away from the capacitor), and pushes and pulls the capacitor, so that the capacitor is periodically deformed. Among them, the moving component 30 can be connected only to the first flexible electrode 50, or only to the dielectric elastomer 40, or simultaneously connected to the dielectric elastomer 40 and the first flexible electrode 50. The first flexible electrode 50 can be located on the side of the dielectric elastomer 40 facing away from the moving component 30, or on the side of the dielectric elastomer 40 facing the moving component 30.

[0025] By setting a first flexible electrode 50 and a second flexible electrode 60 on the dielectric elastomer 40 to form a capacitor, the motion component 30 converts the rotational motion of the cam 20 into reciprocating linear motion, so that the dielectric elastomer 40, the first flexible electrode 50 and the second flexible electrode 60 undergo periodic deformation, and the capacitance of the capacitor undergoes periodic changes to generate electrical energy, thereby realizing the collection of energy from the rotational motion.

[0026] It can be understood that the volume V of the capacitor remains unchanged during the deformation process, the film thickness of the dielectric elastomer 40 is h=V / A (where A is the surface area of ​​one side of the dielectric elastomer 40), and the capacitance C=ε 0 εA / h=ε 0 εA 2 / V(where ε 0 is the absolute dielectric constant in vacuum, ε is the dielectric constant of the dielectric elastomer 40), it can be seen that the capacitance C is proportional to the square of the surface area A of one side of the dielectric elastomer 40 2 Directly proportional. In this embodiment, the outer peripheral profile design of the cam 20 allows the motion component 30 to perform multiple sets of reciprocating motions (4 times in this embodiment) within one rotation of the cam 20. Under the action of the motion component 30, the capacitor will be stretched open, deformed back, stretched open again, deformed back, etc., wherein, during the process of the capacitor deforming back, the capacitance C decreases due to the decrease of A, causing the capacitor to discharge, and thus it can be regarded as the capacitor intermittently generating electrical energy. With such a configuration, when the external excitation shaft 10 drives the cam 20 to rotate one circle, the capacitor is discharged multiple times, greatly improving the output efficiency of electrical energy.

[0027] In this embodiment, a moving assembly 30 and a capacitor are provided on opposite sides of the cam 20, so that the two capacitors can simultaneously convert the rotational mechanical energy into electrical energy, further improving the output efficiency of the electrical energy. In other embodiments, three, four or more capacitors can be provided to improve the output efficiency of the electrical energy.

[0028] In one implementation, see Figure 3 The functional component 70 includes a coil 71 and a magnetic member 72. The first flexible electrode 50 and the second flexible electrode 60 are both electrically connected to the coil 71. The coil 71 is sleeved on the shaft 10 and rotates with the shaft 10. The magnetic member 72 is arranged on a side of the coil 71 facing away from the shaft 10 and is spaced apart from the coil 71.

[0029] When the rotating shaft 10 drives the coil 71 to rotate, the coil 71 cuts the magnetic field generated by the magnetic member 72 to generate an induced electromotive force, so that a voltage exists between the first flexible electrode 50 and the second flexible electrode 60 .

[0030] Specifically, the coil 71 is arranged on opposite sides of the cam 20 and rotates synchronously with the cam 20. The coil 71 can be fixed on the rotating shaft 10, or fixed on the cam 20 to achieve synchronous rotation with the cam 20. In other embodiments, the coil 71 can be arranged only on one side of the cam 20. The induced electromotive force generated by the coil 71 can be directly applied to the first flexible electrode 50 and the second flexible electrode 60, or can be indirectly applied to the first flexible electrode 50 and the second flexible electrode 60 through a structure such as a self-charging circuit. By setting the coil 71 and the magnetic member 72, the coil 71 rotates relative to the magnetic member 72 while following the rotation of the rotating shaft 10 to cut the magnetic field generated by the magnetic member 72 to generate electrical energy, so as to improve the energy collection efficiency of the rotational motion. In this embodiment, a self-charging circuit is added between the coil 71 and the capacitor, and part of the electrical energy generated by the coil 71 is stored, and the other part is provided to the self-charging circuit. The self-charging circuit can store this part of the electrical energy and provide it to the capacitor when the capacitor needs it, so that the capacitor can smoothly collect the energy of the rotational motion, thereby achieving passivity. Compared with the prior art which usually uses an external power supply to power the capacitor, this embodiment uses the coil 71 and the magnetic member 72 to generate electrical energy to power the capacitor, thereby eliminating the need for an external power supply. At the same time, a self-charging circuit is added to facilitate passivity.

[0031] It can be understood that, compared with the energy harvesting device of the external power supply in the prior art, the dielectric-electromagnetic composite rotary energy harvesting device 100 of the present embodiment not only simplifies the device structure, but also greatly improves the energy harvesting efficiency of the rotary motion (i.e., the output efficiency of the electric energy) through the coordinated use of the capacitor and the functional component 70, while being able to realize the energy harvesting of the rotary motion.

[0032] In one implementation, see Figure 2 and Figure 3 The rotary energy harvesting device 100 further includes a housing 80. The cam 20 and the coil 71 are both located in the housing 80, and the magnetic member 72 is disposed on the inner wall of the housing 80 and on opposite sides of the coil 71. By providing the housing 80, the cam 20 and the coil 71 are both disposed in the housing 80. On the one hand, the internal parts can be separated from the outside to avoid being affected by the external environment during the energy harvesting process. On the other hand, it is convenient to install the magnetic member 72 so that the coil 71 can rotate relative to the magnetic member 72.

[0033] Specifically, the magnetic member 72 is fixed on the inner wall of the housing 80. The rotating shaft 10 is rotatably connected to the housing 80, and the moving assembly 30 is slidably connected to the housing 80. Part of the moving assembly 30 is located in the housing 80, and part of it extends out of the housing 80 to connect with the capacitor.

[0034] In one implementation, see Figure 2, the rotary energy harvesting device 100 also includes an annular clamp 90. The dielectric elastomer 40 is arranged outside the shell 80. The annular clamp 90 is arranged at the edge of the second flexible electrode 60 of the dielectric elastomer 40, and fixes the second flexible electrode 60, the dielectric elastomer 40 and the first flexible electrode 50 on the shell 80. Specifically, the outer contour of the annular clamp 90 is the same as the outer contour of the dielectric elastomer 40. In this embodiment, the annular clamp 90 is in a circular ring shape, the dielectric elastomer 40 is a circular film, and the outer diameter of the annular clamp 90 is equal to the outer diameter of the dielectric elastomer 40. Preferably, the shell 80 has an end 81 with an outer contour of a cylindrical surface, and the annular clamp 90 fixes the capacitor on the end 81, and the outer diameters of the dielectric elastomer 40, the annular clamp 90 and the end 81 are equal. The end 81 has a groove to facilitate the motion component 30 to extend from the end 81 and connect to the capacitor. The annular clip 90 is provided to facilitate fixing the capacitor on the housing 80 and to simplify the structure inside the housing to a great extent.

[0035] In one implementation, see Figure 2 The moving component 30 includes a first fixing member 31 disposed between the housing 80 and the first flexible electrode 50. The first fixing member 31 includes a connecting surface 311 connected to the first flexible electrode 50. The connecting surface 311 includes a middle portion 3111 and an edge portion 3112 surrounding the middle portion 3111. When the dielectric elastomer 40, the first flexible electrode 50 and the second flexible electrode 60 are not deformed, the distance between the edge portion 3112 and the first flexible electrode 50 is greater than the distance between the middle portion 3111 and the first flexible electrode 50. By setting the distance between the edge portion 3112 of the connecting surface 311 and the first flexible electrode 50 to be greater than the distance between the middle portion 3111 and the first flexible electrode 50, the relative change of the capacitance of the capacitor under the same deformation of the dielectric elastomer 40 can be increased, thereby increasing the energy output density of the capacitor.

[0036] In one implementation, see Figure 4 , the edge portion 3112 is an arc surface. By setting the edge portion 3112 as an arc surface, during the deformation of the dielectric elastomer 40, it can be ensured that the first flexible electrode 50 is in smooth contact with the first fixing member 31, thereby improving the service life of the capacitor and facilitating improving the service life of the generator.

[0037] In one implementation, see Figure 3The motion component 30 further includes a second fixing member 32 and a third fixing member 33. The second fixing member 32 is disposed on the second flexible electrode 60, one end of the third fixing member 33 is connected to the second fixing member 32, and the other end passes through the dielectric elastomer 40 and is connected to the first fixing member 31. Specifically, the third fixing member 33 may be a screw, a bolt, a pin, etc. By providing the second fixing member 32 and the third fixing member 33, the first fixing member 31 and the third fixing member 33 clamp the capacitor and are fixed to the capacitor, so that the motion component 30 pushes and pulls the capacitor through reciprocating motion to cause the capacitor to deform.

[0038] In one implementation, see Figure 3 The motion assembly 30 includes a push rod 34 and an elastic member 35, and the push rod 34 is slidably connected to the housing 80. The elastic member 35 is arranged between the push rod 34 and the housing 80, so that when the push rod 34 moves away from the cam 20, it is subjected to the elastic force generated by the compression of the elastic member 35. Specifically, the elastic member 35 is preferably a spring. The end of the push rod 34 facing away from the elastic member 35 is connected and fixed to the first fixing member 31 and the second fixing member 32 in sequence through the third fixing member 33. The housing 80 is provided with a stepped hole 101, and the push rod 34 extends out of the housing 80 through the stepped hole 101. The stepped hole 101 includes a connected front section 1011 and a rear section 1012, the front section 1011 is located on the side close to the capacitor, and the elastic member 35 is located in the rear section 1012. The aperture of the front section 1011 is slightly larger than the outer diameter of the push rod 34, and the aperture of the rear section 1012 is slightly larger than the outer diameter of the elastic member 35. The outer diameter of the end of the push rod 34 away from the capacitor is larger than the outer diameter of the end of the push rod 34 close to the capacitor, and smaller than the aperture of the rear section 1012, so that the push rod 34 can slide smoothly relative to the housing 80. By providing the elastic member 35 and the push rod 34, the elastic member 35 is arranged between the push rod 34 and the elastic member 35, and the elastic member 35 can apply an elastic force toward the cam 20 to the push rod 34, so that the push rod 34 drives the capacitor to recover its deformation faster, which is beneficial to improving the power output efficiency. At the same time, the elastic force can also make the push rod 34 resist the cam 20, which can ensure good contact between the push rod 34 and the cam 20, which is beneficial to the smooth and rapid reciprocating movement of the push rod 34.

[0039] In one implementation, see Figure 3 The motion assembly 30 further includes a roller bracket 36 and a roller 37. The roller bracket 36 is connected to the top rod 34, and the roller 37 is arranged on the roller bracket 36 and is rollingly connected to the cam 20. Specifically, the roller bracket 36 is fixed to the top rod 34, and the roller 37 is sleeved on the roller bracket 36 and is slidingly connected to the roller bracket 36. By arranging the roller 37 and the roller bracket 36, the roller 37 is rollingly connected to the cam 20, which reduces friction and improves energy utilization compared to the sliding connection. Moreover, it is also beneficial to improve the service life.

[0040] See also Figure 1 and Figure 2 , an embodiment of the present invention further provides a generator, which is used to convert tidal energy, water energy, wind energy and other energy into electrical energy. The generator includes a rotating part and a rotary energy harvesting device 100 provided by the present invention. The rotating part (not shown) is arranged on the rotating shaft 10 of the rotary energy harvesting device 100, and the rotating part is used to convert the flow of external medium into torque to drive the rotating shaft 10 to rotate. Specifically, the rotating part is preferably a blade, so that the rotating part can convert tidal energy, water energy, wind energy and other energy into torque to drive the rotating shaft 10 to rotate. By adding the rotary energy harvesting device 100 provided by the present invention to the generator, the generator can use the capacitor formed by the dielectric elastomer 40 to collect the energy of the rotational motion, and compared with the existing structure, it has higher power output efficiency, higher energy conversion rate and higher stability. At the same time, since no external power supply is required, the structure is simpler.

[0041] What is disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A rotary energy harvesting device, characterized in that: The invention comprises a rotating shaft, a cam, a moving component, a functional component, a dielectric elastomer, a first flexible electrode and a second flexible electrode, wherein the first flexible electrode and the second flexible electrode are arranged on the dielectric elastomer and form a capacitor, the functional component is electrically connected to the first flexible electrode and the second flexible electrode, the moving component is connected to the cam, the moving component is connected to the first flexible electrode and / or the dielectric elastomer, the rotating shaft is connected to the cam and is used to drive the cam to rotate, so that the moving component moves back and forth, so that the dielectric elastomer, the first flexible electrode and the second flexible electrode are periodically deformed, and the capacitance of the capacitor is periodically changed to generate electric energy; The rotary energy harvesting device also includes a shell, and the dielectric elastomer is arranged outside the shell; the moving component includes a first fixing part arranged between the shell and the first flexible electrode, the first fixing part includes a connecting surface connected to the first flexible electrode, and the connecting surface includes a middle part and an edge part surrounding the middle part; when the dielectric elastomer, the first flexible electrode and the second flexible electrode are not deformed, the distance between the edge part and the first flexible electrode is greater than the distance between the middle part and the first flexible electrode.

2. The rotary energy harvesting device according to claim 1, characterized in that: The functional component includes a coil and a magnetic member, the first flexible electrode and the second flexible electrode are both electrically connected to the coil, the coil is sleeved on the rotating shaft and rotates with the rotating shaft, and the magnetic member is arranged on a side of the coil facing away from the rotating shaft and has a spacing distance from the coil; When the rotating shaft drives the coil to rotate, the coil cuts the magnetic field generated by the magnetic member to generate an induced electromotive force, so that a voltage exists between the first flexible electrode and the second flexible electrode.

3. The rotary energy harvesting device according to claim 2, characterized in that: The cam and the coil are both located in the shell, and the magnetic member is arranged on the inner wall of the shell and located on two opposite sides of the coil.

4. The rotary energy harvesting device according to claim 3, characterized in that: The rotary energy harvesting device also includes an annular clamp, which is arranged on the edge of the second flexible electrode of the dielectric elastomer and fixes the second flexible electrode, the dielectric elastomer and the first flexible electrode to the shell.

5. The rotary energy harvesting device according to claim 1, characterized in that: The edge portion is a curved surface.

6. The rotary energy harvesting device according to claim 1, characterized in that: The moving component also includes a second fixing member and a third fixing member, wherein the second fixing member is arranged on the second flexible electrode, and one end of the third fixing member is connected to the second fixing member, and the other end of the third fixing member passes through the dielectric elastomer and is connected to the first fixing member.

7. The rotary energy harvesting device according to claim 1, characterized in that: The motion assembly comprises a push rod and an elastic member, wherein the push rod is slidably connected to the shell, and the elastic member is arranged between the push rod and the shell, so that when the push rod moves away from the cam, it is subjected to the elastic force generated by the compression of the elastic member.

8. The rotary energy harvesting device according to claim 7, characterized in that: The motion assembly further comprises a roller and a roller bracket, wherein the roller bracket is connected to the push rod, and the roller is arranged on the roller bracket and is rollingly connected to the cam.

9. A generator, characterized in that: It comprises a rotating member and a rotary energy harvesting device as claimed in any one of claims 1 to 8, wherein the rotating member is arranged on a rotating shaft of the rotary energy harvesting device, and the rotating member is used to convert the flow of an external medium into a torque to drive the rotating shaft to rotate.

Images