Distributed electrically driven tire rotational energy harvester

Abstract

This invention discloses a distributed electric-driven tire rotation energy harvester in the field of energy harvesting devices. The device includes a mounting plate with a recessed mounting groove at one end and a central hole for a vehicle axle to pass through. Several electromagnetic components are arranged in a radial pattern within the mounting plate outside the mounting groove, with buffers at both ends. A piezoelectric component is located at the tail end of the electromagnetic components and on the inner wall of the mounting groove. A loading cam is located within the mounting groove and fixedly connected to the vehicle axle, with a permanent magnet at its center repelling the electromagnetic components. A harvesting circuit module is electrically connected to both the electromagnetic and piezoelectric components. The advantages of this invention are: by using a sandwich-style piezoelectric and electromagnetic component, three energy harvests can be completed in a single compression by the loading cam, greatly improving energy harvesting efficiency. Furthermore, the structure is compact and the manufacturing cost is low.

Description

Technical Field

[0001] This invention relates to the field of energy harvesting devices, and more specifically to a distributed electric-driven tire rotation energy harvester. Background Technology

[0002] With the rapid development of electric vehicle technology, distributed electric drive has gained increasing attention as a novel drive system. Employing multiple motors, it offers advantages such as a decentralized powertrain layout and independent control of each wheel, making the safety of motor monitoring particularly crucial. To power the sensors monitoring these motors, utilizing the energy recovered and reused during vehicle movement has become an effective solution.

[0003] Existing technologies already include several methods for recovering and utilizing energy generated during the vehicle's own motion:

[0004] 1. A cantilever beam with a piezoelectric element attached to its fixed end and a mass block attached to its top end is deformed by the centrifugal force generated by the rotational motion of the tires and the inertia of the mass block. This causes the piezoelectric element to deform, and the piezoelectric element outputs electrical energy through the piezoelectric effect.

[0005] 2. By designing a piezoelectric cantilever beam structure with paddles and pins, when the shaft rotates and drives the rotor to rotate, the paddles on its edge periodically paddle the pins at the end of the cantilever beam, and the piezoelectric vibrator continuously generates periodic pulse electrical signals, outputting electrical energy through the piezoelectric effect;

[0006] 3. By fixing a permanent magnet to a rotor that rotates with the shaft and distributing coils around the rotor, the magnetic flux through the coils changes when the rotor rotates, and an induced electromotive force is generated using Faraday's law of electromagnetic induction.

[0007] 4. By arranging permanent magnets according to a certain pattern using a Halbach array, the outward magnetic field is enhanced. As the permanent magnets rotate with the rotor, the magnetic flux through the coils increases, the induced electromotive force increases, and the output electrical energy increases.

[0008] 5. By coating the raceway with interdigitated flexible electrodes, direct contact between the flexible electrodes and the rollers is avoided. The bearing is self-powered by utilizing the electrical signal generated by the periodic friction between the rollers and the raceway interdigitated electrodes.

[0009] However, all five energy recovery methods mentioned above have some problems:

[0010] 1) Aging problem: When the piezoelectric cantilever beam is moved and vibrates, the cantilever beam will experience fatigue. Over time, this will cause the cantilever beam to age and become easily damaged.

[0011] 2) Size issue: Using cantilever beams will increase the size of the energy harvester, which is not conducive to integration and miniaturization;

[0012] 3) Cost issues: The permanent magnets of Halbach arrays are usually made of neodymium iron boron material, which has advantages such as high energy product and high coercivity. However, the price of permanent magnets made of this material is relatively high, which increases the cost.

[0013] 4) Magnetic field utilization rate: Factors such as the magnetic field distribution and coil structure design of the magnetoelectric rotating energy harvester may lead to low magnetic field utilization rate, and some magnetic field energy cannot be effectively converted into electrical energy, thus affecting the output power and harvesting efficiency of the energy harvester.

[0014] 5) The energy harvesting method is limited. Currently, many harvesters use piezoelectric or magnetoelectric structures to harvest rotational energy, which may lead to problems such as low harvesting efficiency.

[0015] To address this, we propose a distributed electric-driven tire rotation energy harvester. Summary of the Invention

[0016] To address the aforementioned shortcomings of the prior art, this invention provides a distributed electric drive tire rotation energy harvester.

[0017] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0018] A distributed electric drive tire rotation energy harvester includes: a mounting plate, which is disc-shaped and has a mounting groove with one end facing inward; a shaft hole for a vehicle axle to pass through the center of the mounting plate; several electromagnetic components, which are embedded in the mounting plate outside the mounting groove in a divergent manner, for recovering energy through the principle of electromagnetic induction; buffers are provided at both ends of the electromagnetic components; a piezoelectric component is located at the tail end of the electromagnetic components and on the inner wall of the mounting groove, for recovering energy through the piezoelectric effect; the piezoelectric component at the tail end of the electromagnetic components and the buffer are fixedly engaged; a loading cam, which is concentrically located in the mounting groove with the mounting plate and fixedly connected to the vehicle axle; a permanent magnet with the same pole repelling the electromagnetic components is provided at the center end of the loading cam; the loading cam is used to compress the piezoelectric component on the inner wall of the mounting groove during rotation; and a harvesting circuit module, which is electrically connected to the electromagnetic components and the piezoelectric components respectively, for harvesting and utilizing the electrical energy generated by the electromagnetic components and the piezoelectric components.

[0019] By setting up a sandwich-like structure with two sets of piezoelectric components and one set of electromagnetic components, the shaft rotates during vehicle movement, driving the loading cam to rotate. The flange on the loading cam compresses the piezoelectric component on the inner wall of the mounting slot to complete piezoelectric power generation. At the same time, the permanent magnet on the loading cam repels the electromagnetic component, causing it to displace and complete electromagnetic power generation. During the displacement of the electromagnetic component, it compresses the piezoelectric component at its tail end to complete piezoelectric power generation again. This combines piezoelectric and magnetoelectric energy harvesting methods, and the cam can complete three energy harvests with a single contact and compression. The electrical energy harvested from the three harvests is collected and used through the harvesting circuit module, which greatly improves the energy harvesting efficiency. Furthermore, it does not use a cantilever beam structure, avoiding the premature damage of the energy harvester caused by excessive fatigue of the cantilever beam. The structure is compact, simple, and inexpensive.

[0020] Further defining the electromagnetic component, it includes an induction coil and a magnetic core. The induction coil is wound around the circumference of the magnetic core, and there is a gap between the two. The buffer is a buffer spring. An inlay groove is opened on the surface of the mounting plate surrounding the mounting groove. Both ends of the magnetic core are locked in the inlay groove by buffer springs. In the unloaded state, both buffer springs are in a pre-tight state. Both ends of the induction coil are electrically connected to the energy recovery control circuit.

[0021] By incorporating a buffer spring, the magnetic core can be displaced due to the repulsion of the permanent magnet. After the permanent magnet is displaced, it can return to its initial position, facilitating the next displacement. The structure is simple and easy to use.

[0022] Further defining the piezoelectric assembly, it includes an inner piezoelectric unit and an outer piezoelectric unit. Both the inner and outer piezoelectric units include a metal pressure plate and a piezoelectric sheet. The metal pressure plate is convex in shape and includes two adhesive plates, two inclined plates connected to the inner side of the adhesive plates, and a top plate connecting the two inclined plates. The metal pressure plate is fixedly connected by the two adhesive plates and the piezoelectric sheet. The piezoelectric sheet of the inner piezoelectric unit is fixedly disposed on the inner wall of the mounting groove, and the piezoelectric sheet of the outer piezoelectric unit is fixedly disposed on the inner wall of the inlay groove located on the outer side of the mounting plate. The metal pressure plate of the outer piezoelectric unit is engaged with a buffer spring.

[0023] By setting up an internal piezoelectric unit and an external piezoelectric unit, the internal piezoelectric unit generates electricity by compressing the flange of the rotating cam, while the external piezoelectric unit generates electricity by compressing the magnetic core through displacement, which greatly improves the energy recovery rate.

[0024] Further, the flange of the loading cam has a magnet hole that passes through the loading cam, and the permanent magnet is locked in the magnet hole. During the rotation of the loading cam, the flange of the loading cam presses against the metal plate of the inner piezoelectric unit. By opening the magnet hole, the permanent magnet is locked in the magnet hole, which is simple in structure and easy to manufacture.

[0025] Further defining the acquisition circuit module, it includes an electromagnetic acquisition circuit and a piezoelectric acquisition circuit. The electromagnetic acquisition circuit is electrically connected to the induction coil, and the piezoelectric acquisition circuit is electrically connected to the piezoelectric sheet. The piezoelectric acquisition circuit and the electromagnetic acquisition circuit acquire energy separately, and then store the energy together for use. Collecting energy separately is more conducive to the circuit layout design.

[0026] Further defining the process of piezoelectric component power generation:

[0027] The piezoelectric equations at both ends of the piezoelectric element are:

[0028] ;

[0029] ;

[0030] in, This refers to the electrical displacement along the thickness direction at both ends of the piezoelectric element when it is subjected to pressure from a metal clamping plate. The electric field strength of the piezoelectric element along its thickness direction. The strain is in the thickness direction of the piezoelectric element. Let be the piezoelectric strain constant at both ends of the piezoelectric element. The elastic compliance coefficient of the materials at both ends of the piezoelectric element. The dielectric constant of the materials at both ends of the piezoelectric element is denoted as . This represents the component of the stress experienced by the piezoelectric element along the thickness direction of the piezoelectric element.

[0031] The piezoelectric equation for the middle part of the piezoelectric element is:

[0032] ;

[0033] ;

[0034] in, , The width of the piezoelectric element; , This refers to the electrical displacement of the center of the piezoelectric element along its thickness direction. The strain is along the length of the piezoelectric element. The piezoelectric strain constant is located in the middle of the piezoelectric element. The elastic flexibility coefficient of the material in the middle of the piezoelectric element. This is the equivalent concentrated force of the force acting on the inclined plate along the thickness direction of the piezoelectric sheet. This is the equivalent concentrated force of the force acting on the inclined plate along the length of the piezoelectric element. Let be the component of the stress on the piezoelectric element along its length. The thickness of the piezoelectric element, The length of a single adhesive board;

[0035] The method for calculating the power generation of a piezoelectric component is as follows:

[0036] Calculate the length of the cavity formed by the inclined plate, the top plate, and the middle of the piezoelectric sheet. The total length of the adhesive board , Let the length of the inclined plate be . The length of the top plate;

[0037] Force analysis shows that the force exerted by the inclined plate on the bonding area along the thickness direction of the piezoelectric sheet can be equivalent to a concentrated force acting along the width direction of the piezoelectric sheet. The force exerted by the inclined plate on the bonding area along the length of the piezoelectric sheet can be equivalent to a concentrated force acting along the length of the piezoelectric sheet. The torque exerted by the top plate on the inclined plate is The torque exerted by the adhesive plate on the inclined plate is And satisfy:

[0038] ;

[0039] ;

[0040] Furthermore, the deflection of the inclined plate is defined as... ,satisfy The boundary conditions are: ,in, , This refers to the bending stiffness per unit width of the metal sheet. The elastic modulus of the metal sheet. The acute angle between the inclined plate and the piezoelectric sheet;

[0041] Calculate the deflection of the inclined plate :

[0042] ;

[0043] The deformation of the piezoelectric element along its length direction satisfies:

[0044] ;

[0045] Since there is no external electric field, the equivalent concentrated force is calculated. :

[0046] ;

[0047] in, This refers to the pressure exerted on the metal tablet.

[0048] Therefore, the power generation of a piezoelectric component is determined by pressure. Electricity generated :

[0049] .

[0050] Further specifying, the method for calculating the power generation of the electromagnetic components is as follows:

[0051] The radius of the induction coil of the electromagnetic component is The area enclosed by the induction coil ;

[0052] When the magnetic core in the induction coil moves outward due to the repulsive force between the permanent magnet and the polar magnet inside the loading cam, the magnetic flux of the magnetic core in the induction coil increases. A change occurs, which in turn generates an induced electromotive force. ;

[0053] Based on the angle between the direction of the magnetic field and the normal direction of the plane of the induction coil Establish a calculation model for the magnetic flux of a magnetic iron core;

[0054] ;

[0055] The magnetic flux at the point where the magnetic core reaches its maximum displacement due to the repulsive displacement of the permanent magnet is calculated using a magnetic flux calculation model. The magnetic flux that returns the magnetic core to its initial position ,use and Calculate the induced electromotive force ;

[0056] ;

[0057] ;

[0058] in, The magnetic flux density of the magnetic iron core. The number of turns of the induction coil. The rate of change of magnetic flux. This represents the change in magnetic flux of the magnetic core during the process of displacement and recovery. This is the time it takes for the magnetic core to return to its initial position after being displaced.

[0059] The beneficial effects of this invention are as follows: by setting up a sandwich-type piezoelectric component and an electromagnetic component, three energy harvests can be completed in one compression of the loading cam, which greatly improves the efficiency of energy harvesting, and the structure is compact and the manufacturing cost is low. Attached Figure Description

[0060] Figure 1 This is a front view of the present invention;

[0061] Figure 2 for Figure 1 An enlarged schematic diagram of part A in the middle;

[0062] Figure 3 This is a schematic diagram of the piezoelectric component.

[0063] Figure 4 This is the circuit diagram of the piezoelectric data acquisition circuit;

[0064] Figure 5 This is the circuit schematic of the electromagnetic acquisition circuit.

[0065] The symbols for each component are as follows:

[0066] Mounting plate 1, mounting groove 11, shaft hole 12, inlay groove 13, electromagnetic component 2, induction coil 21, magnetic iron core 22, buffer component 23, piezoelectric component 3, inner piezoelectric unit 31, metal pressure plate 311, adhesive plate 3111, inclined plate 3112, top plate 3113, piezoelectric sheet 312, outer piezoelectric unit 32, loading cam 4, magnet hole 41, permanent magnet 42. Detailed Implementation

[0067] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0068] Example:

[0069] like Figures 1-3As shown, a distributed electric drive tire rotation energy harvester includes a mounting plate 1, an electromagnetic component 2, a piezoelectric component 3, a loading cam 4, and a harvesting circuit module. The mounting plate 1 is disc-shaped with a mounting groove 11 recessed at one end. A shaft hole 12 for a vehicle axle to pass through is opened at the center of the mounting plate 1. Several electromagnetic components 2 are arranged in a divergent manner within the mounting plate 1 outside the mounting groove 11, and are used to recover energy through electromagnetic induction. Buffers 23 are provided at both ends of the electromagnetic components 2. The electromagnetic components 2 include an induction coil 21 and a magnetic core 22. The induction coil 21 is wound around the circumference of the magnetic core 22, and there is a gap between the two. The buffers 23 serve as a buffer. The mounting plate 1 surrounding the spring has an inlay groove 13. Both ends of the magnetic core 22 are secured in the inlay groove 13 by buffer springs. In the unloaded state, both buffer springs are in a pre-tightened state. Both ends of the induction coil 21 are electrically connected to the energy recovery control circuit. The piezoelectric component 3 is located at the tail end of the electromagnetic component 2 and on the inner wall of the mounting groove 11, and is used to recover energy through the piezoelectric effect. The piezoelectric component 3 at the tail end of the electromagnetic component 2 and the buffer 23 are fixedly engaged. The piezoelectric component 3 includes an inner piezoelectric unit 31 and an outer piezoelectric unit 32. Both the inner piezoelectric unit 31 and the outer piezoelectric unit 32 include a metal pressure plate 311 and a piezoelectric plate 312. The metal pressure plate 311 is convex in shape. The pressure plate 311 includes two adhesive plates 3111, two inclined plates 3112 connected to the inner side of the adhesive plates 3111, and a top plate 3113 connecting the two inclined plates 3112. The metal pressure plate 311 is fixedly connected to the two adhesive plates 3111 and the piezoelectric plate 312. The piezoelectric plate 312 of the inner piezoelectric unit 31 is fixedly disposed on the inner wall of the mounting groove 11, and the piezoelectric plate 312 of the outer piezoelectric unit 32 is fixedly disposed on the inner wall of the inlay groove 13 located on the outer side of the mounting plate 1. The metal pressure plate 311 of the outer piezoelectric unit 32 is snapped with a buffer spring. The loading cam 4 is concentrically disposed in the mounting groove 11 with the mounting plate 1 and fixedly connected to the automobile axle. The center end of the loading cam 4 is provided with a permanent magnet that is repelled by the same pole as the electromagnetic component 2. The magnet 42 and the loading cam 4 are used to press the piezoelectric component 3 on the inner wall of the mounting groove 11 during rotation. The flange of the loading cam 4 has a magnet hole 41 that passes through the loading cam 4. The permanent magnet 42 is locked in the magnet hole 41. During the rotation of the loading cam 4, the flange of the loading cam 4 presses the metal pressure plate 311 of the inner piezoelectric unit 31. The acquisition circuit module is electrically connected to the electromagnetic component 2 and the piezoelectric component 3 respectively. The acquisition circuit is used to collect and utilize the electrical energy generated by the electromagnetic component 2 and the piezoelectric component 3. The acquisition circuit module includes an electromagnetic acquisition circuit and a piezoelectric acquisition circuit. The electromagnetic acquisition circuit is electrically connected to the induction coil 21, and the piezoelectric acquisition circuit is electrically connected to the piezoelectric plate 312.

[0070] like Figure 4 As shown, in Figure 4All ports 1 are connected to one end of the acquisition capacitor, and all ports 2 are connected to the other end. The piezoelectric acquisition circuit uses a self-powered multi-input hybrid rectifier (SP-MIHR). This circuit uses an RC differential (RCD) circuit and PKD to control the switch, effectively eliminating the full-bridge rectifier (FBR) in the traditional S-SSHI circuit. When two bending piezoelectric units harvest energy simultaneously, the current through inductor L flows in the same direction, effectively solving the charge elimination problem encountered in traditional TDM circuits when two bending piezoelectric units use inductors simultaneously. Furthermore, inductor L, diodes D1 and D2, MOSFETs M1 and M2, and resistor Rd within the RCD structure are all shared in the SP-HIMR circuit. This method not only saves components but also significantly reduces the circuit size, thereby reducing power consumption.

[0071] like Figure 5 As shown, in Figure 5 All ports 1 are connected to one end of the acquisition capacitor, and all ports 2 are connected to the other end. The magnetoelectric acquisition circuit uses a four-stage voltage multiplier. During the negative half-cycle of the input, the AC power supply charges capacitor C1+ through diode D1+ and capacitor C3+ through diode D3+. The AC power supply and capacitor C1+ charge capacitor C2+ through diode D2+, and also charge capacitor C4+ through C3+ and D4+. The other half of the circuit is the same. When the system starts, the voltage detector output is low. When the circuit is switched on, AC power charges capacitor Co through the Cockcroft-Walton (CW) voltage multiplier circuit. When the voltage across capacitor Co reaches the threshold voltage, the voltage detector goes high. Shutdown. The voltage across capacitor Co stabilizes at the threshold voltage, and the connection between the startup circuit and the electromagnetic generator is disconnected. Once a stable output is established, the output of the AC / DC converter powers the control circuit, cutting off the startup circuit and reducing unnecessary energy consumption.

[0072] In this application, during the power generation process of the piezoelectric component 3:

[0073] The piezoelectric equations at both ends of piezoelectric element 312 are as follows:

[0074] ;

[0075] ;

[0076] in, The electric displacement of the piezoelectric element 312 in the thickness direction at both ends when the piezoelectric element 312 is subjected to pressure from the metal pressure plate 311. The electric field strength of the piezoelectric element 312 in its thickness direction. The strain in the thickness direction of piezoelectric element 312 is... The piezoelectric strain constants at both ends of piezoelectric element 312 are... The elastic flexibility coefficient of the materials at both ends of the piezoelectric element 312 is... The dielectric constant of the materials at both ends of the piezoelectric element 312 is... This represents the component of the stress on the piezoelectric element 312 along the thickness direction of the piezoelectric element 312.

[0077] The piezoelectric equation for the middle part of piezoelectric element 312 is:

[0078] ;

[0079] ;

[0080] in, , The width of the piezoelectric element 312; , The electrical displacement of the center of the piezoelectric element 312 in the thickness direction of the piezoelectric element 312. The strain along the length of piezoelectric element 312; The piezoelectric strain constant of the middle part of piezoelectric element 312 is... The elastic flexibility coefficient of the material in the middle of piezoelectric element 312. This is the equivalent concentrated force of the force acting on the inclined plate 3112 along the thickness direction of the piezoelectric sheet 312. This is the equivalent concentrated force of the force acting on the inclined plate 3112 along the length of the piezoelectric sheet 312. Let be the component of the stress on the piezoelectric element 312 along its length. The thickness of the piezoelectric element 312 The length of a single adhesive board 3111;

[0081] The calculation method for the power generation of piezoelectric component 3 is as follows:

[0082] Calculate the length of the cavity formed by the inclined plate 3112, the top plate 3113, and the piezoelectric sheet 312. Among them, the total length of the adhesive plate 3111 , The length of the inclined plate 3112 The length of the top plate 3113;

[0083] Force analysis shows that the force exerted by the inclined plate 3112 on the bonding area along the thickness direction of the piezoelectric sheet 312 can be equivalent to a concentrated force acting along the width direction of the piezoelectric sheet 312. The force exerted by the inclined plate 3112 on the bonding area along the length of the piezoelectric sheet 312 can be equivalent to a concentrated force acting along the length of the piezoelectric sheet 312. The torque exerted by the top plate 3113 on the inclined plate 3112 is The torque exerted by the adhesive plate 3111 on the inclined plate 3112 is And satisfy:

[0084] ;

[0085] ;

[0086] Furthermore, the deflection of the inclined plate 3112 is defined as... ,satisfy The boundary conditions are: ,in, , The bending stiffness per unit width of the metal sheet is 311. The elastic modulus of metal sheet 311. The acute angle between the inclined plate 3112 and the piezoelectric sheet 312;

[0087] Calculate the deflection of inclined plate 3112 :

[0088] ;

[0089] The deformation of the piezoelectric element 312 along its length direction satisfies:

[0090] ;

[0091] Since there is no external electric field, the equivalent concentrated force is calculated. :

[0092] ;

[0093] in, The pressure exerted on the metal pressure plate 311;

[0094] Therefore, the power generation of piezoelectric component 3 is determined by pressure. Electricity generated :

[0095] .

[0096] The method for calculating the power generation of electromagnetic components is as follows:

[0097] The radius of the induction coil 21 of the electromagnetic component is The area enclosed by the induction coil 21 is ;

[0098] When the magnetic core 22 in the induction coil 21 moves outward due to the repulsive force between the permanent magnet 42 and the same pole magnet in the loading cam 4, the magnetic flux of the magnetic core 22 in the induction coil 21 is increased. A change occurs, which in turn generates an induced electromotive force. ;

[0099] Based on the angle between the direction of the magnetic field and the normal direction of the plane of the induction coil 21 Establish a magnetic flux calculation model for magnetic core 22;

[0100] ;

[0101] The magnetic flux at the point where the repulsive displacement of the magnetic core 22 by the permanent magnet 42 reaches its maximum was calculated using a magnetic flux calculation model. The magnetic flux that returns the magnetic core 22 to its initial position ,use and Calculate the induced electromotive force ;

[0102] ;

[0103] ;

[0104] in, The magnetic flux density of the magnetic core 22 is... The number of turns of induction coil 21 The rate of change of magnetic flux. This represents the change in magnetic flux of the magnetic core 22 during the process from displacement to recovery. This is the time taken for the magnetic core 22 to return to its initial position after being displaced.

[0105] By setting up a sandwich-like structure with two sets of piezoelectric components 3 and one set of electromagnetic components 2, the axle rotates during vehicle movement, driving the loading cam 4 to rotate. The flange on the loading cam 4 compresses the piezoelectric component 3 on the inner wall of the mounting groove 11, completing piezoelectric power generation. Simultaneously, the permanent magnet 42 on the loading cam 4 repels the electromagnetic component 2, causing it to displace and completing electromagnetic power generation. During the displacement of the electromagnetic component 2, it compresses the piezoelectric component 3 at its tail end, again completing piezoelectric power generation. This combines piezoelectric and magnetoelectric energy harvesting methods, and three energy harvests can be completed with a single contact and compression of the cam. The electrical energy harvested from these three harvests is collected and used through the harvesting circuit module, greatly improving energy harvesting efficiency. Furthermore, the absence of a cantilever beam structure avoids premature energy harvesting caused by excessive fatigue of the cantilever beam. In the event of damage and malfunction, the structure is compact, simple, and inexpensive. A buffer spring is incorporated to allow the magnetic core 22 to shift due to the repulsion of the permanent magnet 42, and the permanent magnet 42 to return to its initial position after displacement, facilitating the next shift. The structure is simple and easy to use. The inclusion of an inner piezoelectric unit 31 and an outer piezoelectric unit 32 significantly improves energy recovery. The inner piezoelectric unit 31 generates electricity by pressing the magnetic core 22 with a rotating flange, while the outer piezoelectric unit 32 generates electricity by pressing the magnetic core 22 with displacement. The permanent magnet 42 is secured within a magnet hole 41, resulting in a simple structure and easy manufacturing. The separate collection of energy by the piezoelectric and electromagnetic acquisition circuits, followed by storage and reuse, facilitates circuit layout design.

Claims

1. A distributed electric-driven tire rotation energy harvester, characterized in that, include: The mounting plate (1) is in the shape of a disc and has a mounting groove (11) with one end facing inward. The mounting plate (1) has a shaft hole (12) for passing through the automobile axle. Electromagnetic components (2) are provided in a plurality of them. The plurality of electromagnetic components (2) are embedded in the mounting plate (1) outside the mounting groove (11) in a divergent manner to recover energy through the principle of electromagnetic induction. The first and last ends of the electromagnetic components (2) are provided with buffers (23). The piezoelectric component (3) is located at the tail end of the electromagnetic component (2) and on the inner wall of the mounting groove (11) for recovering energy through the piezoelectric effect. The piezoelectric component (3) and the buffer (23) at the tail end of the electromagnetic component (2) are fixed together. The loading cam (4) is concentrically located in the mounting groove (11) and fixedly connected to the automobile axle. The center end of the loading cam (4) is provided with a permanent magnet (42) that is repulsive to the electromagnetic component (2). The loading cam (4) is used to compress the piezoelectric component (3) on the inner wall of the mounting groove (11) during rotation. The acquisition circuit module is electrically connected to the electromagnetic component (2) and the piezoelectric component (3) respectively. The acquisition circuit is used to acquire and utilize the electrical energy generated by the electromagnetic component (2) and the piezoelectric component (3).

2. The distributed electric drive tire rotation energy harvester according to claim 1, characterized in that, The electromagnetic component (2) includes an induction coil (21) and a magnetic core (22). The induction coil (21) is wound around the circumference of the magnetic core (22) and there is a gap between them. The buffer (23) is a buffer spring. An inlay groove (13) is provided on the plate surface of the mounting plate (1) surrounding the mounting groove (11). Both ends of the magnetic core (22) are locked in the inlay groove (13) by the buffer spring. In the unloaded state, both buffer springs are in a pre-tight state. Both ends of the induction coil (21) are electrically connected to the energy recovery control circuit.

3. The distributed electric drive tire rotation energy harvester according to claim 2, characterized in that, The piezoelectric assembly (3) includes an inner piezoelectric unit (31) and an outer piezoelectric unit (32). Both the inner piezoelectric unit (31) and the outer piezoelectric unit (32) include a metal plate (311) and a piezoelectric plate (312). The metal plate (311) is convex in shape and includes two adhesive plates (3111), two inclined plates (3112) connected to the inner side of the adhesive plates (3111), and a top plate connecting the two inclined plates (3112). 3113), the metal pressure plate (311) is fixedly connected to the two adhesive plates (3111) and the piezoelectric plate (312). The piezoelectric plate (312) of the inner piezoelectric unit (31) is fixedly disposed on the inner wall of the mounting groove (11), and the piezoelectric plate (312) of the outer piezoelectric unit (32) is fixedly disposed on the inner wall of the inlay groove (13) located outside the mounting plate (1). The metal pressure plate (311) of the outer piezoelectric unit (32) is snapped into the buffer spring.

4. The distributed electric drive tire rotation energy harvester according to claim 3, characterized in that, The loading cam (4) has a magnet hole (41) that passes through it on its flange. The permanent magnet (42) is installed in the magnet hole (41). During the rotation of the loading cam (4), the flange of the loading cam (4) presses against the metal plate (311) of the inner piezoelectric unit (31).

5. The distributed electric drive tire rotation energy harvester according to claim 4, characterized in that, The acquisition circuit module includes an electromagnetic acquisition circuit and a piezoelectric acquisition circuit. The electromagnetic acquisition circuit is electrically connected to the induction coil (21), and the piezoelectric acquisition circuit is electrically connected to the piezoelectric sheet (312).

6. The distributed electric drive tire rotation energy harvester according to claim 5, characterized in that, During the power generation process of the piezoelectric component (3): The piezoelectric equations at both ends of the piezoelectric element (312) are as follows: ； ； in, The electric displacement in the thickness direction at both ends of the piezoelectric element (312) when the piezoelectric element (312) is subjected to pressure from the metal plate (311) is called the electric displacement. The electric field strength of the piezoelectric element (312) in its thickness direction. For the strain in the thickness direction of the piezoelectric sheet (312), The piezoelectric strain constants at both ends of the piezoelectric element (312) are... The elastic flexibility coefficient of the material at both ends of the piezoelectric element (312) is... The dielectric constant of the materials at both ends of the piezoelectric element (312) is... The component of the stress on the piezoelectric sheet (312) along the thickness direction of the piezoelectric sheet (312); The piezoelectric equation for the middle part of the piezoelectric element (312) is: ； ； in, , The width of the piezoelectric element (312); , The electrical displacement of the center of the piezoelectric element (312) in the thickness direction of the piezoelectric element (312) is given by the piezoelectric element (312). The strain along the length of the piezoelectric element (312) is the strain. The piezoelectric strain constant of the middle part of the piezoelectric element (312) is... The elastic flexibility coefficient of the material in the middle of the piezoelectric sheet (312) is... The equivalent concentrated force is the force acting on the inclined plate (3112) along the thickness direction of the piezoelectric sheet (312). The equivalent concentrated force is the force acting on the inclined plate (3112) along the length of the piezoelectric piece (312). Let be the component of the stress on the piezoelectric element (312) along the length of the piezoelectric element (312). The thickness of the piezoelectric element (312) is... The length of a single adhesive board (3111); The method for calculating the power generation of the piezoelectric component (3) is as follows: Calculate the length of the cavity formed by the inclined plate (3112), the top plate (3113), and the piezoelectric sheet (312). The total length of the adhesive plate (3111) is... , The length of the inclined plate (3112) The length of the top plate (3113); Through force analysis, the force exerted by the inclined plate (3112) on the bonding area along the thickness direction of the piezoelectric sheet (312) can be equivalent to a concentrated force acting in the width direction of the piezoelectric sheet (312). The force exerted by the inclined plate (3112) on the bonding area along the length of the piezoelectric sheet (312) can be equivalent to a concentrated force acting along the length of the piezoelectric sheet (312). The torque exerted by the top plate (3113) on the inclined plate (3112) is The torque exerted by the adhesive plate (3111) on the inclined plate (3112) is And satisfy: ； ； Furthermore, the deflection of the inclined plate (3112) is defined as... ,satisfy The boundary conditions are: ,in, , The bending stiffness per unit width of the metal sheet (311) The elastic modulus of the metal sheet (311) is given. The acute angle between the inclined plate (3112) and the piezoelectric sheet (312); Calculate the deflection of the inclined plate (3112) : ； The deformation of the piezoelectric sheet (312) along its length direction satisfies: ； Since there is no external electric field, the equivalent concentrated force is calculated. : ； in, The pressure exerted on the metal sheet (311); Therefore, the power generation of the piezoelectric component (3) is determined by the pressure. Electricity generated : 。 7. The distributed electric drive tire rotation energy harvester according to claim 5, characterized in that, The method for calculating the power generation of the electromagnetic component is as follows: The radius of the induction coil (21) of the electromagnetic component is The area enclosed by the induction coil (21) is... ; When the magnetic core (22) in the induction coil (21) moves outward due to the repulsive force between the permanent magnet (42) and the same pole magnet in the loading cam (4), the magnetic flux of the magnetic core (22) in the induction coil (21) is increased. A change occurs, which in turn generates an induced electromotive force. ; Based on the angle between the direction of the magnetic field and the direction of the normal to the plane of the induction coil (21) Establish a magnetic flux calculation model for the magnetic core (22); ； The magnetic flux at the point where the magnetic core (22) reaches its maximum displacement due to the repulsive displacement of the permanent magnet (42) is calculated using a magnetic flux calculation model. The magnetic flux that returns the magnetic core (22) to its initial position ,use and Calculate the induced electromotive force ; ； ； in, The magnetic induction intensity of the magnetic core (22) is The number of turns of the induction coil (21) The rate of change of magnetic flux. The change in magnetic flux of the magnetic core (22) during the displacement and recovery process is given by the magnetic core (22). The time taken for the magnetic core (22) to return to its initial position after displacement.

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