A planar electromagnetic energy harvesting device

Abstract

The application discloses a planar electromagnetic energy collection device, and belongs to the field of vibration energy collection.The device comprises a planar spring, a cylindrical permanent magnet, a planar coil, a filling type three-dimensional winding and a fixing structure.The planar electromagnetic energy collection device adopts a composite coil of a non-uniform distribution coil and a filling type three-dimensional coil on the basis of a traditional collector, improves the space utilization of the device and the power density of the device.The non-uniform distribution coil uses a non-uniform distribution method on the basis of a traditional planar coil, and improves the energy conversion rate of the planar coil.The filling type three-dimensional coil combines a three-dimensional coil and a baffle, effectively reduces the volume proportion of the mechanical structure of the device.The planar spring-vibration pickup system of the application suppresses the torsional vibration of the system and improves the vibration stability of the device.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-power energy harvesting, and in particular to a planar electromagnetic energy harvesting device that uses non-uniformly distributed coils and filled three-dimensional coils to improve the electromagnetic energy conversion efficiency of the device. Background Art

[0002] To increase the power density of electromagnetic energy harvesting devices, non-uniformly distributed coils and padded three-dimensional coils are used to enhance device integration. Chinese invention patent specification CN201510390833.8 discloses a piezoelectric-electromagnetic composite micro-environmental vibration energy harvester. This device also utilizes microplanar coils placed in the center of shallow grooves on the upper and lower covers to collect electromagnetic energy.

[0003] In the above two vibration energy harvesting devices using planar induction coils, the planar coils are distributed with equal diameters in the coil plane. However, due to the uneven distribution of the spatial magnetic field in the coil plane, the coupling effect between the planar coils with equal diameters and the magnetic field is poor, and their energy conversion efficiency is low, thereby reducing the power of the planar vibration energy harvesting device. This limits the scope of use of the planar vibration energy harvesting device. On the other hand, both of the above vibration energy harvesting devices have a large number of baffle areas, which compress the placement of the coils. However, as Figure 1 As shown, the permanent magnet has a large amount of magnetic field energy at the location where the baffle is placed. Summary of the Invention

[0004] In response to the problems existing in the coil design of existing planar vibration energy harvesting devices, the purpose of the present invention is to provide a planar electromagnetic energy harvesting device that uses non-uniformly distributed coils and filled three-dimensional coils, aiming to solve the problem of low electromagnetic energy conversion efficiency in existing planar vibration energy harvesting devices due to the uniform equal-diameter distribution of planar coils and low space utilization of the device, and to reduce the volume of the planar vibration energy harvesting device and improve the power density of the device.

[0005] To achieve the above-mentioned object, the present invention provides a planar electromagnetic energy harvesting device, comprising: two planar springs, a cylindrical permanent magnet, two layers of planar coils, a plurality of filled three-dimensional coils, and a fixing structure;

[0006] The inner sides of the two planar springs are respectively fitted with the upper and lower surfaces of the cylindrical magnet, and the planar springs respectively coincide with the central axis of the cylindrical magnet;

[0007] The filled three-dimensional coil is located between the two planar springs as a first baffle I and is sleeved on the cylindrical magnet;

[0008] The outer side of each of the two planar springs is provided with a filled three-dimensional coil as a second baffle II.

[0009] The outer side of each of the two second baffles II is provided with a planar coil.

[0010] The two planar springs, the cylindrical permanent magnet, the two planar coils and the plurality of filled three-dimensional coils are fixed by the fixing structure.

[0011] Optionally, each of the two planar springs adopts a three-beam structure, the beams are divided into inner beams and outer beams, and the inner beams and the outer beams are connected by a circular ring.

[0012] Optionally, the planar coil adopts a non-uniform distribution structure.

[0013] Optionally, the planar coil comprises an inner coil and an outer coil arranged outside the inner coil, the wire diameter of the outer coil is larger than that of the inner coil, the outer coil is arranged in a loose manner, and the inner coil is arranged in a tight manner.

[0014] Optionally, the filled three-dimensional coil is formed by being inlaid in a coagulable liquid material and being cooled and processed.

[0015] Optionally, the first baffle I is provided with a through hole at the center, the diameter of the through hole is equal to the diameter of the cylindrical permanent magnet, and the thickness of the first baffle I is thinner than the overall thickness of the planar spring.

[0016] Optionally, the centers of the two planar coils and the plurality of filled three-dimensional coils coincide with the central axis of the cylindrical magnet.

[0017] Optionally, the planar spring, the cylindrical permanent magnet, the planar coil and the filled three-dimensional coil are of the same shape, and the outer contour shadows of the planar spring, the cylindrical permanent magnet, the planar coil and the filled three-dimensional coil obtained by projection along the direction of the central axis of the cylindrical magnet coincide.

[0018] Optionally, the device further comprises a shell for mounting the planar spring, the cylindrical permanent magnet, the planar coil, the filled three-dimensional coil and the fixing structure.

[0019] Optionally, the fixing structure fixes the two planar springs, the cylindrical permanent magnet, the two planar coils and the plurality of filled three-dimensional coils in a detachable manner.

[0020] 1. The planar electromagnetic energy harvesting device provided by the application comprises two planar springs, a cylindrical permanent magnet, two layers of planar coils, a plurality of filled three-dimensional coils and a fixing structure; the inner sides of the two planar springs are respectively attached to the upper and lower surfaces of the cylindrical magnet, and the planar springs are respectively coincident with the central axis of the cylindrical magnet; the filled three-dimensional coil as the first baffle I is located between the two planar springs and is sleeved on the cylindrical magnet; the outer sides of the two planar springs are respectively provided with a filled three-dimensional coil as the second baffle II; the outer sides of the two second baffles II are respectively provided with a layer of planar coil; and the two planar springs, the cylindrical permanent magnet, the two layers of planar coils and the plurality of filled three-dimensional coils are fixed by the fixing structure. The planar spring-vibration pickup system formed by the two planar springs, the cylindrical permanent magnet, the two layers of planar coils, the plurality of filled three-dimensional coils and the fixing structure reduces the required volume of the mechanical structure to improve the integration of the device. Meanwhile, the system adopts the spring-magnet-spring system structure, suppresses the torsional vibration of the system and improves the vibration stability of the device. Moreover, the structure of the application improves the space utilization of the device.

[0021] 2. The application uses a non-uniform planar coil, matches the electromagnetic energy distribution in the plane by the non-equal-diameter distribution of the coil in the plane of the coil, improves the electromagnetic energy conversion efficiency of the coil to improve the power density of the planar vibration energy harvesting device.

[0022] 3. The application adopts the filled three-dimensional coil, combines the coil with the baffle, reduces the structural volume of the device and improves the power density of the device. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the application, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description are only one embodiment of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0024] Figure 1 is a space magnetic field energy simulation schematic diagram of a permanent magnet according to an embodiment of the application;

[0025] Figure 2 is a structural schematic diagram of a planar electromagnetic energy harvesting device according to an embodiment of the application;

[0026] Among them, 1, cylindrical permanent magnet; 2, planar spring; 3, non-uniform distribution planar coil; 4, first baffle I; 5, second baffle II; 6, bolt;

[0027] Figure 3 is a planar spring structure schematic diagram according to an embodiment of the application;

[0028] Figure 4 is a structural schematic diagram of a non-uniform distribution coil according to an embodiment of the present application;

[0029] Figure 5 is a three-dimensional view and a sectional view of a filled three-dimensional coil according to an embodiment of the present application;

[0030] Figure 6 is a simplified schematic diagram of a vibration energy harvesting device according to an embodiment of the present application. DETAILED DESCRIPTION

[0031] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0032] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should fall within the scope of protection of the present application.

[0033] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-described accompanying drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented. In addition, the terms "comprise" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to the process, method, product or device.

[0034] Embodiment 1

[0035] As Figure 2 is a structural schematic diagram of a planar electromagnetic energy harvesting device according to an embodiment of the present application, as Figure 2 shown, the planar electromagnetic energy harvesting device comprises two planar springs 2, a cylindrical permanent magnet 1, two layers of non-uniform distribution planar coils 3, a plurality of filled three-dimensional coils and a fixing structure;

[0036] The inner sides of the two planar springs 2 are respectively attached to the upper and lower surfaces of the cylindrical magnet, and the planar springs 2 are respectively coincident with the central axis of the cylindrical magnet; the filling type three-dimensional coil as the first baffle I 4 is located between the two planar springs 2 and is sleeved on the cylindrical magnet; the outer sides of the two planar springs 2 are respectively provided with a filling type three-dimensional coil as the second baffle II 5; the outer sides of the two second baffles II 5 are respectively provided with a layer of non-uniformly distributed planar coil 3; the two planar springs 2, the cylindrical permanent magnet 1, the two layers of non-uniformly distributed planar coils 3 and the plurality of filling type three-dimensional coils are fixed through a fixing structure.

[0037] As shown in Figure 3 , the two planar springs 2 are the same springs, both adopting a three-beam structure, the beams being divided into inner beams and outer beams, and the inner beams being connected with the outer beams by a circular ring.

[0038] As shown in Figure 4 , the non-uniformly distributed planar coil 3 adopts a non-uniformly distributed structure, including an inner layer coil and an outer layer coil arranged outside the inner layer coil, the wire diameter of the outer layer coil being larger than that of the inner layer coil, the outer layer coil being loosely arranged, and the inner layer coil being closely arranged.

[0039] As shown in Figure 5 , the filling type three-dimensional coil is a rectangular plate, the rectangular plate is provided with a through hole, and the size of the through hole is set according to needs. For example, the center of the first baffle I 4 is provided with a through hole, and the diameter of the through hole is equal to the diameter of the cylindrical permanent magnet 1.

[0040] As an optional embodiment, the filling type three-dimensional coil is formed by embedding a three-dimensional winding in a coagulable liquid material and then cooling and processing.

[0041] The manufacturing process of the filling type three-dimensional coil includes: according to the structure of the device and the position of the baffle, the inner diameter, the outer diameter and the thickness of the filling type three-dimensional coil are limited. After the coil parameters are determined, the coil is wound using a mold. After winding is completed, the coagulable liquid is poured into the mold. After the liquid is cooled, the filling type three-dimensional coil is obtained.

[0042] Continuing to refer to Figure 2 , the centers of the two layers of non-uniformly distributed planar coils 3 and the plurality of filling type three-dimensional coils are coincident with the central axis of the cylindrical magnet.

[0043] The planar spring 2, the cylindrical permanent magnet 1, the non-uniformly distributed planar coil 3 and the filling type three-dimensional coil have the same shape, and the outer contours of the planar spring 2, the cylindrical permanent magnet 1, the non-uniformly distributed planar coil 3 and the filling type three-dimensional coil coincide when projected along the central axis direction of the cylindrical magnet, for example, the planar spring 2, the cylindrical permanent magnet 1, the non-uniformly distributed planar coil 3 and the filling type three-dimensional coil are all square plates.

[0044] As an optional embodiment, the planar electromagnetic energy collection device further comprises a housing for mounting the planar spring 2, the cylindrical permanent magnet 1, the non-uniformly distributed planar coil 3, the filled three-dimensional coil and the fixing structure.

[0045] As an optional embodiment, the fixing structure detachably fixes the two planar springs 2, the cylindrical permanent magnet 1, the two layers of non-uniformly distributed planar coils 3 and the plurality of filled three-dimensional coils.

[0046] Specifically, the fixing structure adopts bolts 6 and nuts to symmetrically fix the four corners of the planar spring 2, the cylindrical permanent magnet 1, the non-uniformly distributed planar coil 3, the filled three-dimensional coil and the fixing structure.

[0047] The specific working principle of the planar vibration energy device of the present application will be described in detail below to make the skilled in the art better understand the present application. Figure 6 The specific working principle of the planar vibration energy device of the present application will be described in detail below to make the skilled in the art better understand the present application.

[0048] When a stable and weak sinusoidal impact is externally given to the planar vibration energy device, the planar spring of the device will resonate, amplify the sinusoidal vibration and drive the permanent magnet to move, and the movement of the permanent magnet Can be described as:

[0049]

[0050] wherein, f is the frequency of the sinusoidal impact, A is the amplitude of the sinusoidal motion.

[0051] The moving permanent magnet generates a changing electromagnetic field in space, which can be described as:

[0052]

[0053] wherein is the derivative of the magnetic flux density with respect to time. is the derivative of the magnetic flux with respect to the Z direction. The magnetic field generated by the cylindrical magnet can be expressed as the magnetic flux density at any point in space:

[0054]

[0055] wherein, J m is the equivalent surface charge density of the cylindrical magnet. r mag is the radius of the permanent magnet, h is the height of the permanent magnet.

[0056] The induced voltage of the planar coil can be described as:

[0057]

[0058] wherein, r seg n is the number of turns of the inner layer coil, in n is the number of turns of the outer layer coil, ot n is the number of turns of the outer layer coil, d d is the wire spacing. d wd_in d is the wire diameter of the inner layer coil, d wd_ot d is the wire diameter of the outer layer coil, d is the wire diameter of the three-dimensional winding. n1 is the number of turns of a single layer of the three-dimensional winding, and n2 is the number of layers of the three-dimensional winding.

[0059] The parasitic resistance of a single-turn coil can be described as:

[0060]

[0061] wherein p is the electrical conductivity of the coil material, r coil D is the coil thickness, d wd d is the coil wire diameter. Thus, the total impedance of the coil can be described as:

[0062] +

[0063] Thus, the maximum total output power of the coil can be described as:

[0064]

[0065] This maximum total power calculation formula can obtain the extreme point of the maximum total power with respect to the inner and outer diameters by derivation to determine the optimal inner and outer diameters of the coil.

[0066] The above only describes the preferred embodiments of the present application, and it should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A planar electromagnetic energy harvesting device, characterized by, The utility model relates to a kind of magnetic field generator, including: Two plane springs, cylindrical permanent magnet, two layers of plane coils, multiple filling three-dimensional coils and fixed structure; The inner side of two plane springs respectively is attached with the upper and lower surfaces of cylindrical magnet, and plane spring is coincident with the central axis of cylindrical magnet respectively; The filling three-dimensional coil as first baffle I is located between two plane springs, and is sleeved on the cylindrical magnet; Two plane springs are respectively provided with a filling three-dimensional coil as second baffle II outside; Two second baffles II are respectively provided with a layer of plane coil outside; Two plane springs, cylindrical permanent magnet, two layers of plane coils and multiple filling three-dimensional coils are fixed by the fixed structure; The plane coil adopts non-uniform distribution structure;The plane coil includes inner layer coil and outer layer coil arranged outside inner layer coil, and the wire diameter of outer layer coil is greater than the wire diameter of inner layer coil, and outer layer coil is loosely arranged, and inner layer coil is closely arranged.

2. The planar electromagnetic energy-harvesting device of claim 1, wherein, Two plane springs all adopt three-beam structure, and beam is divided into inner beam and outer beam, and the inner beam is connected with outer beam by circular ring.

3. The planar electromagnetic energy-harvesting device of claim 1, wherein, The filling three-dimensional coil is inlayed in coagulable liquid material by three-dimensional winding and is formed by cooling processing.

4. The planar electromagnetic energy-harvesting device of claim 1, wherein, The center of two layers of plane coils and multiple filling three-dimensional coils is coincident with the central axis of cylindrical magnet.

5. The planar electromagnetic energy-harvesting device of claim 1, wherein, It also includes shell, and the shell is used to install plane spring, cylindrical permanent magnet, plane coil, filling three-dimensional coil and fixed structure.

6. The planar electromagnetic energy-harvesting device of claim 1, wherein, The fixed structure can detachably fix two plane springs, cylindrical permanent magnet, two layers of plane coils and multiple filling three-dimensional coils.

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