Distributed electric drive tire rotation energy collector

Abstract

The invention discloses a distributed electrically-driven tire rotation energy collector in the field of energy collection devices, which comprises a mounting plate, one end face of the mounting plate is concavely provided with a mounting groove, and the center position of the mounting plate is provided with a shaft hole for an automobile shaft rod to pass through; the electromagnetic assemblies are embedded in the positions, on the outer side of the mounting groove, of the mounting plate in a divergent mode, and buffering pieces are arranged at the head ends and the tail ends of the electromagnetic assemblies; the piezoelectric assembly is arranged at the tail end of the electromagnetic assembly and the inner wall of the mounting groove; the loading cam is arranged in the mounting groove and fixedly connected to the automobile shaft rod, and a permanent magnet which is in homopolar repulsion with the electromagnetic assembly is arranged at the circle center end of the loading cam; the acquisition circuit module is electrically connected with the electromagnetic assembly and the piezoelectric assembly; the energy collection device has the beneficial effects that by arranging the sandwich type piezoelectric assembly and the electromagnetic assembly, three times of energy collection can be completed in one-time compression of the loading cam, the energy collection efficiency is greatly improved, the structure is compact, and the manufacturing cost is low.

Description

Technical Field

[0001] The invention relates to the field of energy harvesting devices, and in particular to a distributed electric-driven tire rotation energy harvester. Background Art

[0002] With the rapid development of electric vehicle technology, distributed electric drive has received more and more attention as a new type of drive. It uses multiple motors for control, has the advantages of decentralized power system layout and independent control of each wheel, so it is particularly important to monitor the safety of the motor. In order to power the sensors that monitor the motor, recycling and utilizing the energy during the vehicle's own movement has become an effective solution.

[0003] There are some existing methods in the prior art to recover and utilize the energy during the vehicle's own movement:

[0004] 1. Through a cantilever beam with a piezoelectric sheet attached to the fixed end and a mass block attached to the top, the centrifugal force generated by the rotation of the tire and the inertia of the mass block is used to deform the cantilever beam, thereby driving the piezoelectric sheet to deform, and the piezoelectric sheet outputs electrical energy through the piezoelectric effect;

[0005] 2. By designing a paddle-thrust piezoelectric cantilever beam structure, when the shaft rotates and drives the rotor to rotate, the paddle on its edge periodically plucks the thrust pin 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 the permanent magnet on the rotor that rotates with the shaft and distributing the coils around the rotor, the magnetic flux passing through the coils changes when the rotor rotates, and using Faraday's law of electromagnetic induction, an induced electromotive force is generated;

[0007] 4. The permanent magnets are arranged in a certain pattern through the Halbach array to enhance the outward magnetic field. As the permanent magnets rotate with the rotor, the magnetic flux passing through the coil will increase, the induced electromotive force generated will also increase, and the output electrical energy will increase;

[0008] 5. By applying the interdigital flexible electrode on the raceway, direct contact between the flexible electrode and the roller is avoided, and the bearing is self-powered by using the electrical signal generated by the periodic friction between the roller and the interdigital electrode on the raceway;

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

[0010] 1) Aging problem: When the piezoelectric cantilever beam is vibrated by being moved, the cantilever beam will become fatigued. In the long run, the cantilever beam will age and be easily damaged.

[0011] 2) Volume problem: using cantilever beams will increase the volume of the energy harvester, which is not conducive to integration and miniaturization;

[0012] 3) Cost issue: The permanent magnets of Halbach arrays usually use neodymium iron boron materials, which have advantages such as high magnetic energy product and high coercivity. However, the permanent magnets made of this material are relatively expensive, increasing the cost.

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

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

[0015] Therefore, we propose a distributed electric drive tire rotary energy harvester. Summary of the Invention

[0016] In view of the above deficiencies of the prior art, the present invention provides a distributed electric drive tire rotary energy harvester.

[0017] To achieve the above invention objective, the technical solution adopted by the present invention is as follows:

[0018] A distributed electric drive tire rotary energy harvester, comprising: a mounting plate, which is disc-shaped and has a mounting groove recessed inward at one end. An axle hole for passing through the vehicle axle is provided at the central position of the mounting plate; a plurality of electromagnetic components, which are radially embedded in the mounting plate outside the mounting groove and are used to recover energy through the principle of electromagnetic induction. Buffer members are provided at both the head and tail ends of the electromagnetic components; a piezoelectric component, which is provided at the tail end of the electromagnetic component and the inner wall of the mounting groove and is used to recover energy through the piezoelectric effect. The piezoelectric component at the tail end of the electromagnetic component and the buffer member are clamped and fixed; a loading cam, which is concentrically arranged in the mounting groove with the mounting plate and is fixedly connected to the vehicle axle. A permanent magnet that repels the same pole as the electromagnetic component is provided at the center end of the loading cam. The loading cam is used to press the piezoelectric component on the inner wall of the mounting groove during rotation; a collection circuit module, which is electrically connected to the electromagnetic component and the piezoelectric component respectively, and the collection circuit is used to collect and utilize the electrical energy generated by the electromagnetic component and the piezoelectric component.

[0019] By setting two sets of piezoelectric components and one set of electromagnetic components to form a sandwich shape, during the driving process of the vehicle, the shaft rotates, driving the loading cam to rotate. The flange on the loading cam presses against the piezoelectric components on the inner wall of the mounting groove to complete piezoelectric power generation. At the same time, the permanent magnet on the loading cam repels the electromagnetic component, causing it to displace to complete electromagnetic power generation. During the displacement of the electromagnetic component, it presses against the piezoelectric component at the end of the electromagnetic component to complete piezoelectric power generation again. This combines two energy harvesting methods of piezoelectric and magnetoelectric, and the cam can complete three energy harvestings with one contact and compression. The electrical energy from the three energy harvestings is collected and used through the acquisition circuit module, greatly improving the energy harvesting efficiency. And the cantilever beam structure is not used, avoiding the situation where the energy harvester is damaged in advance and unable to work due to excessive fatigue of the cantilever beam. The structure is small, simple, and has a low cost.

[0020] Further defined, the electromagnetic component includes an induction coil and a magnetic iron core. The induction coil is wound around the circumferential surface of the magnetic iron core, and there is a gap between them. The buffer is a buffer spring. Embedding grooves are provided on the plate surface of the mounting plate outside the mounting groove. Both ends of the magnetic iron core are clamped in the embedding grooves through buffer springs. In the unloaded state, both buffer springs are in a pre-tightened state. Both ends of the induction coil are electrically connected to the energy recovery control circuit.

[0021] By setting the buffer spring, when the magnetic iron core displaces due to the repulsion of the permanent magnet, it can return to the initial position after the displacement of the permanent magnet is misaligned, facilitating the occurrence of the next displacement. The structure is simple and easy to use.

[0022] Further defined, the piezoelectric component includes an inner piezoelectric unit and an outer piezoelectric unit. Both the inner piezoelectric unit and the outer piezoelectric unit include a metal pressing sheet and a piezoelectric sheet. The metal pressing sheet is in a convex shape. The metal pressing sheet includes two bonding plates, two inclined plates connected to the inner sides of the bonding plates, and a top plate connecting the two inclined plates. The metal pressing sheet is fixedly connected to the piezoelectric sheet through the two bonding plates. The piezoelectric sheet of the inner piezoelectric unit is fixedly arranged on the inner wall of the mounting groove, and the piezoelectric sheet of the outer piezoelectric unit is fixedly arranged on the inner wall of the embedding groove located outside the mounting plate. The metal pressing sheet of the outer piezoelectric unit is clamped with the buffer spring.

[0023] By setting the inner piezoelectric unit and the outer piezoelectric unit, the inner piezoelectric unit is pressed by the flange of the rotating cam to generate electricity, and the outer piezoelectric unit is pressed by the displacement of the magnetic iron core to generate electricity, greatly improving the energy recovery rate.

[0024] Further defined, a magnet hole penetrating the loading cam is provided on the flange of the loading cam, and the permanent magnet is clamped in the magnet hole. During the rotation of the loading cam, the flange of the loading cam presses against the metal pressing sheet of the inner piezoelectric unit; by providing the magnet hole and clamping the permanent magnet in the magnet hole, the structure is simple and convenient to manufacture.

[0025] Further defined, 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, and the piezoelectric acquisition circuit is electrically connected to the piezoelectric sheet. The piezoelectric acquisition circuit and the electromagnetic acquisition circuit collect energy respectively, and then store the energy together for use. Separated collection is more conducive to the circuit layout design.

[0026] Further defined, during the power generation process of the piezoelectric component:

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

[0028] D 3ends = ε 33 E3 + d 33 T3;

[0029] S3 = d 33 E3 + s 33 T3;

[0030] Among them, D 3ends is the electric displacement in the thickness direction at both ends of the piezoelectric sheet when the piezoelectric sheet is subjected to the pressure of the metal pressing sheet, E3 is the electric field direction during the power generation of the piezoelectric sheet, S3 is the strain in the thickness direction of the piezoelectric sheet, d 33 is the piezoelectric strain constant at both ends of the piezoelectric sheet, s 33 is the elastic compliance coefficient of the material at both ends of the piezoelectric sheet, ε 33 is the dielectric constant of the material at both ends of the piezoelectric sheet, and T3 is the component of the stress received by the piezoelectric sheet along the thickness direction of the piezoelectric sheet;

[0031] The piezoelectric equations in the middle of the piezoelectric sheet are:

[0032] D 3middle = ε 33 E3 + d 31 T1;

[0033] S1 = d 31 E3 + s 11 T1;

[0034] Among them, b is the width of the piezoelectric sheet; D 3middle is the electric displacement in the thickness direction of the middle of the piezoelectric sheet, S1 is the strain in the length direction of the piezoelectric sheet; d 31 is the piezoelectric strain constant in the middle of the piezoelectric sheet, s 11 is the elastic compliance coefficient of the material in the middle of the piezoelectric sheet, F1 is the equivalent concentrated force of the force acting on the inclined plate along the length direction of the piezoelectric sheet, F2 is the equivalent concentrated force of the force acting on the inclined plate along the thickness direction of the piezoelectric sheet, T1 is the component of the stress received by the piezoelectric sheet along the length direction of the piezoelectric sheet, t pis the thickness of the piezoelectric sheet, and l1 is the length of the bonding plate;

[0035] The power generation calculation method of the piezoelectric component is as follows:

[0036] Calculate the length l of the cavity formed by the inclined plate, the top plate and the middle part of the piezoelectric sheet c = 2l2 cosθ + l3, where the total length l of the bonding plate b = 2l1, l2 is the length of the inclined plate, and l3 is the length of the top plate;

[0037] Through force analysis, it can be obtained that the force exerted by the inclined plate on the bonding part in the thickness direction of the piezoelectric sheet can be equivalent to a concentrated force F3 acting in the width direction of the piezoelectric sheet, and the force exerted by the inclined plate on the bonding part in the length direction of the piezoelectric sheet can be equivalent to a concentrated force F4 acting in the length direction of the piezoelectric sheet. The moment exerted by the top plate on the inclined plate is M1, and the moment exerted by the bonding plate on the inclined plate is M2, and they satisfy:

[0038]

[0039] M1 = 0, M2 = (F1cosθ - F2 sinθ)l2;

[0040] And, define the deflection of the inclined plate as ω1, which satisfies The boundary conditions are:

[0041]

[0042] Among them, B s is the flexural rigidity of the metal pressing sheet, and E m is the elastic modulus of the metal pressing sheet, and θ is the acute angle between the inclined plate and the piezoelectric sheet;

[0043] Calculate the deflection ω1 of the inclined plate:

[0044]

[0045] Then the deformation of the piezoelectric sheet in its length direction satisfies:

[0046] S1l c = 2ω1sinθ;

[0047] Since there is no external electric field, calculate the equivalent concentrated force F2:

[0048]

[0049] Among them, N is the pressure exerted on the metal pressing sheet;

[0050] Therefore, the power generation of the piezoelectric component is the electric quantity Q generated by the pressure N g :

[0051]

[0052] Further defined, the power generation calculation method of the electromagnetic component is as follows:

[0053] If the radius of the induction coil of the electromagnetic component is r, the area S surrounded by the induction coil is S = πr 2 ;

[0054] When the magnetic iron core in the induction coil moves outward due to the repulsive force between the permanent magnet and the like-pole magnet in the loading cam, the magnetic flux Φ of the magnetic iron core in the induction coil changes, and then an induced electromotive force E is generated;

[0055] Establish a magnetic flux calculation model of the magnetic iron core according to the included angle θ' between the magnetic field direction and the normal direction of the induction coil plane;

[0056] Φ = BScosθ';

[0057] Use the magnetic flux calculation model to calculate the magnetic flux Φ1 at the maximum displacement of the magnetic iron core under the repulsive force of the permanent magnet and the magnetic flux Φ2 when the magnetic iron core returns to the initial position, and use Φ1 and Φ2 to calculate the induced electromotive force E;

[0058]

[0059] ΔΦ = Φ2 - Φ1;

[0060] Among them, B is the magnetic induction intensity of the magnetic iron core, n is the number of turns of the induction coil, is the change rate of the magnetic flux, ΔΦ is the change amount of the magnetic flux during the displacement and recovery process of the magnetic iron core, and Δt is the time taken for the magnetic iron core to move from the displacement to the initial position.

[0061] The beneficial effects of the present invention are as follows: By setting the sandwich-type piezoelectric component and electromagnetic component, three energy collections can be completed in one compression of the loading cam, greatly improving the energy collection efficiency, and the structure is compact and the manufacturing cost is low. Brief Description of the Drawings

[0062] Figure 1 is the front view of the present invention;

[0063] Figure 2 is Figure 1 the enlarged schematic view of part A in

[0064] Figure 3 is the structural schematic view of the piezoelectric component;

[0065] Figure 4 is the circuit schematic diagram of the piezoelectric acquisition circuit;

[0066] Figure 5 It is the circuit schematic diagram of the electromagnetic acquisition circuit.

[0067] The symbols of each component are as follows:

[0068] Mounting plate 1, mounting groove 11, shaft hole 12, inlay groove 13, electromagnetic component 2, induction coil 21, magnetic iron core 22, buffer 23, piezoelectric component 3, inner piezoelectric unit 31, metal pressing sheet 311, bonding plate 3111, inclined plate 3112, top plate 3113, piezoelectric sheet 312, outer piezoelectric unit 32, loading cam 4, magnet hole 41, permanent magnet 42. Specific embodiments

[0069] The specific embodiments of the present invention will be described below to facilitate the understanding of the present invention by those skilled in the art. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions created using the concept of the present invention are within the scope of protection.

[0070] Embodiment:

[0071] As Figures 1 - 3As shown in the figure, a distributed electric drive tire rotation energy collector includes a mounting plate 1, an electromagnetic component 2, a piezoelectric component 3, a loading cam 4, and a collection circuit module. The mounting plate 1 is in the shape of a round cake, and one end faces inward with a concave mounting groove 11. A shaft hole 12 for passing through the vehicle axle is provided at the center of the mounting plate 1. A number of electromagnetic components 2 are provided, and the number of electromagnetic components 2 is embedded in the mounting plate 1 outside the mounting groove 11 in a divergent shape for recovering energy by the principle of electromagnetic induction. Buffer members 23 are provided at both the head and tail ends of the electromagnetic component 2. The electromagnetic component 2 includes an induction coil 21 and a magnetic iron core 22. The induction coil 21 is wound around the circumferential surface of the magnetic iron core 22, and there is a gap between the two. The buffer member 23 is a buffer spring. Mosaic grooves 13 are provided on the plate surface of the mounting plate 1 outside the mounting groove 11. Both ends of the magnetic iron core 22 are clamped in the mosaic grooves 13 through buffer springs. In the unloaded state, both buffer springs are in a pre-tensioned state. Both ends of the induction coil 21 are electrically connected to the energy recovery control circuit. The piezoelectric component 3 is provided at the tail end of the electromagnetic component 2 and the inner wall of the mounting groove 11 for recovering energy through the piezoelectric effect. The piezoelectric component 3 at the tail end of the electromagnetic component 2 and the buffer member 23 are clamped and fixed. 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 pressing sheet 311 and a piezoelectric sheet 312. The metal pressing sheet 311 is in a convex shape. The metal pressing sheet 311 includes two bonding plates 3111, two inclined plates 3112 connected to the inner sides of the bonding plates 3111, and a top plate 3113 connecting the two inclined plates 3112. The metal pressing sheet 311 is fixedly connected to the piezoelectric sheet 312 through the two bonding plates 3111. The piezoelectric sheet 312 of the inner piezoelectric unit 31 is fixedly provided on the inner wall of the mounting groove 11, and the piezoelectric sheet 312 of the outer piezoelectric unit 32 is fixedly provided on the inner wall of the mosaic groove 13 located outside the mounting plate 1. The metal pressing sheet 311 of the outer piezoelectric unit 32 is clamped with the buffer spring. The loading cam 4 is concentrically arranged in the mounting groove 11 with the mounting plate 1 and is fixedly connected to the vehicle axle. A permanent magnet 42 that repels the same pole as the electromagnetic component 2 is provided at the center end of the loading cam 4. The loading cam 4 is used to press the piezoelectric component 3 on the inner wall of the mounting groove 11 during rotation. A magnet hole 41 penetrating the loading cam 4 is provided on the flange of the loading cam 4. The permanent magnet 42 is clamped in the magnet hole 41. During the rotation of the loading cam 4, the flange of the loading cam 4 presses the metal pressing sheet 311 of the inner piezoelectric unit 31. The collection circuit module is electrically connected to the electromagnetic component 2 and the piezoelectric component 3 respectively. The collection circuit is used to collect and utilize the electric energy generated by the electromagnetic component 2 and the piezoelectric component 3. The collection circuit module includes an electromagnetic collection circuit and a piezoelectric collection circuit. The electromagnetic collection circuit is electrically connected to the induction coil 21, and the piezoelectric collection circuit is electrically connected to the piezoelectric sheet 312.

[0072] As Figure 4 shown, in Figure 4All 1-ports are connected to one end of the acquisition capacitor, and all 2-ports are connected to the other end of the acquisition capacitor. 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 switches, effectively eliminating the full-bridge rectifier (FBR) in the traditional S-SSHI circuit. When two flextensional piezoelectric elements collect energy simultaneously, the current flowing through the inductor L flows in the same direction, effectively solving the charge cancellation problem encountered in the traditional TDM circuit when two flextensional piezoelectric elements use an inductor simultaneously. In addition, the inductor L, diodes D1 and D2, MOSFETs M1 and M2, and the 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 size of the circuit, thereby reducing power consumption.

[0073] As Figure 5 shown, in Figure 5 all 1-ports are also connected to one end of the acquisition capacitor, and all 2-ports are connected to the other end of the acquisition capacitor. The magnetoelectric acquisition circuit uses a four-stage voltage multiplier; in the negative half-cycle of the input, the AC power source charges the capacitor C1+ through the diode D1+ and charges C3+ through the diode D3+; the AC power source and the capacitor C1+ charge the capacitor C2+ through the diode D2+, and also charge C4+ through C3+ and D4+. The other half of the circuit is the same. When the system starts, the output of the voltage detector is at a low level. DM p is turned on, and the AC power source charges the capacitor Co through the Cockcroft-Walton (CW) voltage multiplier circuit. When the voltage on the capacitor Co reaches the threshold voltage, the voltage detector becomes high, and DM p is turned off. The voltage on the capacitor Co stabilizes at the threshold voltage, and the connection between the startup circuit and the electromagnetic generator is cut off. Once a stable output is established, the output of the AC-DC converter is used to power the control circuit, and the startup circuit is cut off to reduce unnecessary energy consumption.

[0074] In this application, during the power generation process of the piezoelectric component 3:

[0075] The piezoelectric equations at both ends of the piezoelectric sheet 312 are:

[0076] D 3ends = ε 33 E3 + d 33 T3;

[0077] S3 = d 33 E3 + s 33 T3;

[0078] Among them, D 3ends$D_3$ is the electric displacement at both ends of the piezoelectric sheet 312 in the thickness direction when the piezoelectric sheet 312 is subjected to the pressure of the metal pressing sheet 311, $E_3$ is the electric field direction when the piezoelectric sheet 312 generates electricity, $S_3$ is the strain in the thickness direction of the piezoelectric sheet 312, and $d$ 33 is the piezoelectric strain constant at both ends of the piezoelectric sheet 312, and $s$ 33 is the elastic compliance coefficient of the material at both ends of the piezoelectric sheet 312, and $\epsilon$ 33 is the dielectric constant of the material at both ends of the piezoelectric sheet 312, and $T_3$ is the component of the stress applied to the piezoelectric sheet 312 in the thickness direction of the piezoelectric sheet 312;

[0079] The piezoelectric equation in the middle of the piezoelectric sheet 312 is:

[0080] $D$ 3middle $=\epsilon$ 33 $E_3 + d$ 31 $T_1$;

[0081] $S_1 = d$ 31 $E_3 + s$ 11 $T_1$;

[0082] Among them, $b$ is the width of the piezoelectric sheet 312; $D$ 3middle is the electric displacement in the thickness direction of the middle of the piezoelectric sheet 312, and $S_1$ is the strain in the length direction of the piezoelectric sheet 312; $d$ 31 is the piezoelectric strain constant in the middle of the piezoelectric sheet 312, and $s$ 11 is the elastic compliance coefficient of the material in the middle of the piezoelectric sheet 312, $F_1$ is the equivalent concentrated force of the force acting on the inclined plate 3112 in the length direction of the piezoelectric sheet 312, $F_2$ is the equivalent concentrated force of the force acting on the inclined plate 3112 in the thickness direction of the piezoelectric sheet 312, $T_1$ is the component of the stress applied to the piezoelectric sheet 312 in the length direction of the piezoelectric sheet 312, and $t$ p is the thickness of the piezoelectric sheet 312, and $l_1$ is the length of the bonding plate 3111;

[0083] The calculation method of the power generation of the piezoelectric component 3 is:

[0084] Calculate the length $l$ of the cavity formed by the inclined plate 3112, the top plate 3113 and the middle of the piezoelectric sheet 312 c $= 2l_2\cos\theta + l_3$, where the total length $l$ of the bonding plate 3111 b $= 2l_1$, $l_2$ is the length of the inclined plate 3112, and $l_3$ is the length of the top plate 3113;

[0085] Through force analysis, it can be obtained that the force exerted by the inclined plate 3112 on the bonding part along the thickness direction of the piezoelectric sheet 312 can be equivalent to a concentrated force F3 acting in the width direction of the piezoelectric sheet 312, and the force exerted by the inclined plate 3112 on the bonding part along the length direction of the piezoelectric sheet 312 can be equivalent to a concentrated force F4 acting in the length direction of the piezoelectric sheet 312. The moment exerted by the top plate 3113 on the inclined plate 3112 is M1, and the moment exerted by the bonding plate 3111 on the inclined plate 3112 is M2, and they satisfy:

[0086]

[0087] M1 = 0, M2 = (F1cosθ - F2sinθ)l2;

[0088] Furthermore, define the deflection of the inclined plate 3112 as ω1, which satisfies The boundary conditions are:

[0089]

[0090] Among them, B s is the flexural rigidity of the metal pressing sheet 311, E m is the elastic modulus of the metal pressing sheet 311, and θ is the acute angle between the inclined plate 3112 and the piezoelectric sheet 312;

[0091] Calculate the deflection ω1 of the inclined plate 3112:

[0092]

[0093] Then the deformation of the piezoelectric sheet 312 in its length direction satisfies:

[0094] S1l c = 2ω1sinθ;

[0095] Since there is no external electric field, calculate the equivalent concentrated force F2:

[0096]

[0097] Among them, N is the pressure exerted on the metal pressing sheet 311;

[0098] Therefore, the generated electricity of the piezoelectric component 3 is the electric quantity Q generated by the pressure N g :

[0099]

[0100] The calculation method for the generated electricity of the electromagnetic component is:

[0101] The radius of the induction coil 21 of the electromagnetic component is r, then the area S surrounded by the induction coil 21 is S = πr 2;

[0102] When the magnetic iron core 22 in the induction coil 21 moves outward under the repulsive force between the like-pole magnets of the permanent magnet 42 in the loading cam 4, the magnetic flux Φ of the magnetic iron core 22 in the induction coil 21 changes, and then an induced electromotive force E is generated.

[0103] Establish a magnetic flux calculation model of the magnetic iron core 22 according to the included angle θ′ between the magnetic field direction and the normal direction of the plane of the induction coil 21.

[0104] Φ = BScosθ′;

[0105] Use the magnetic flux calculation model to calculate the magnetic flux Φ1 at the maximum displacement of the magnetic iron core 22 under the repulsive force of the permanent magnet 42 and the magnetic flux Φ2 when the magnetic iron core 22 returns to the initial position, and use Φ1 and Φ2 to calculate the induced electromotive force E.

[0106]

[0107] ΔΦ = Φ2 - Φ1;

[0108] Among them, B is the magnetic induction intensity of the magnetic iron core 22, n is the number of turns of the coil of the induction coil 21, is the change rate of the magnetic flux, ΔΦ is the change amount of the magnetic flux during the process of the magnetic iron core 22 from displacement to recovery, and Δt is the time taken for the magnetic iron core 22 to move from displacement to return to the initial position.

[0109] By arranging two sets of piezoelectric components 3 and one set of electromagnetic components 2 in a sandwich shape, during the driving process of the vehicle, the shaft rotates, driving the loading cam 4 to rotate. The flange on the loading cam 4 presses against the piezoelectric component 3 on the inner wall of the installation groove 11 to complete piezoelectric power generation. At the same time, the permanent magnet 42 on the loading cam 4 repels the electromagnetic component 2 to cause displacement to complete electromagnetic power generation. During the displacement of the electromagnetic component 2, it presses against the piezoelectric component 3 at the tail end of the electromagnetic component 2 to complete piezoelectric power generation again. This combines two energy harvesting methods of piezoelectricity and magnetoelectricity, and the cam can complete three energy harvestings with one contact pressure. The electrical energy from the three energy harvestings is collected and used through the collection circuit module, greatly improving the energy harvesting efficiency. Moreover, the cantilever beam structure is not used, avoiding the situation where the energy harvester is damaged in advance and unable to work due to excessive fatigue of the cantilever beam. The structure is small, simple, and low in cost; by setting a buffer spring, when the magnetic iron core 22 is displaced due to the repulsion of the permanent magnet 42, it can return to the initial position after the displacement of the permanent magnet 42 is misaligned, facilitating the occurrence of the next displacement. The structure is simple and easy to use; by setting an inner piezoelectric unit 31 and an outer piezoelectric unit 32, the inner piezoelectric unit 31 is pressed by the flange of the cam rotation to generate electricity, and the outer piezoelectric unit 32 is pressed by the displacement of the magnetic iron core 22 to generate electricity, greatly improving the energy recovery rate; by opening a magnet hole 41 and clamping the permanent magnet 42 in the magnet hole 41, the structure is simple and convenient to manufacture; the piezoelectric collection circuit and the electromagnetic collection circuit collect energy separately, and then store the energy together for use. Separated collection is more conducive to the layout design of the circuit.

Claims

1. A distributed electric drive tire rotation energy collector, characterized in that Comprising: An installation plate (1), which is disc-shaped and has an inwardly concave installation groove (11) at one end. An axle hole (12) for passing through an automobile axle rod is provided at the central position of the installation plate (1); A plurality of electromagnetic components (2), which are radially embedded in the installation plate (1) outside the installation groove (11) and are used for recovering energy by the principle of electromagnetic induction. Buffer members (23) are provided at both the head and tail ends of the electromagnetic component (2); A piezoelectric component (3), which is provided at the tail end of the electromagnetic component (2) and the inner wall of the installation groove (11) and is used for recovering energy by the piezoelectric effect. The piezoelectric component (3) at the tail end of the electromagnetic component (2) and the buffer member (23) are clamped and fixed; A loading cam (4), which is concentric with the installation plate (1) and is arranged in the installation groove (11) and is fixedly connected to the automobile axle rod. A permanent magnet (42) that repels the same pole as the electromagnetic component (2) is provided at the center end of the loading cam (4). The loading cam (4) is used for pressing the piezoelectric component (3) on the inner wall of the installation groove (11) during rotation; A collection circuit module, which is electrically connected to the electromagnetic component (2) and the piezoelectric component (3) respectively. The collection circuit is used for collecting and utilizing the electric energy generated by the electromagnetic component (2) and the piezoelectric component (3).

2. The distributed electric drive tire rotation energy collector according to claim 1, characterized in that, The electromagnetic component (2) includes an induction coil (21) and a magnetic iron core (22). The induction coil (21) is wound around the circumferential surface of the magnetic iron core (22) and there is a gap between them. The buffer member (23) is a buffer spring. Embedding grooves (13) are provided on the plate surface of the installation plate (1) outside the installation groove (11). Both ends of the magnetic iron core (22) are clamped in the embedding grooves (13) through the buffer springs. In the non-loaded state, both buffer springs are in a pre-tightened state. Both ends of the induction coil (21) are electrically connected to an energy recovery control circuit.

3. The distributed electric drive tire rotation energy collector according to claim 2, wherein 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 pressing sheet (311) and a piezoelectric sheet (312). The metal pressing sheet (311) is convex-shaped. The metal pressing sheet (311) includes two bonding plates (3111), two inclined plates (3112) connected to the inner sides of the bonding plates (3111), and a top plate (3113) connecting the two inclined plates (3112). The metal pressing sheet (311) is fixedly connected to the piezoelectric sheet (312) through the two bonding plates (3111). The piezoelectric sheet (312) of the inner piezoelectric unit (31) is fixedly arranged on the inner wall of the installation groove (11), and the piezoelectric sheet (312) of the outer piezoelectric unit (32) is fixedly arranged on the inner wall of the embedding groove (13) located outside the installation plate (1). The metal pressing sheet (311) of the outer piezoelectric unit (32) is clamped with the buffer spring.

4. The distributed electric drive tire rotation energy collector according to claim 3, characterized in that A magnet hole (41) penetrating through the loading cam (4) is formed on the flange of the loading cam (4), and the permanent magnet (42) is clamped in the magnet hole (41). During the rotation of the loading cam (4), the flange of the loading cam (4) presses the metal pressing piece (311) of the inner piezoelectric unit (31).

5. The distributed electric drive tire rotation energy collector according to claim 4, wherein, 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 collector according to claim 5, characterized in that, During the power generation process of the piezoelectric assembly (3): The piezoelectric equation at both ends of the piezoelectric sheet (312) is: D 3ends = ε 33 E3 + d 33 T3; S3 = d 33 E3 + s 33 T3; Among them, D 3ends is the electric displacement in the thickness direction at both ends of the piezoelectric sheet (312) when the piezoelectric sheet (312) is subjected to the pressure of the metal pressing sheet (311), E3 is the electric field direction when the piezoelectric sheet (312) generates electricity, S3 is the strain in the thickness direction of the piezoelectric sheet (312), d 33 is the piezoelectric strain constant at both ends of the piezoelectric sheet (312), s 33 is the elastic compliance coefficient of the material at both ends of the piezoelectric sheet (312), ε 33 is the dielectric constant of the material at both ends of the piezoelectric sheet (312), and T3 is the component of the stress received by the piezoelectric sheet (312) in the thickness direction of the piezoelectric sheet (312); The piezoelectric equation in the middle of the piezoelectric sheet (312) is: D 3middle = ε 33 E3 + d 31 T1; S1 = d 31 E3 + s 11 T1; Among them, b is the width of the piezoelectric sheet (312); D 3middle is the electric displacement in the thickness direction of the middle of the piezoelectric sheet (312), S1 is the strain in the length direction of the piezoelectric sheet (312); d 31 is the piezoelectric strain constant in the middle of the piezoelectric sheet (312), s 11 is the elastic compliance coefficient of the material in the middle of the piezoelectric sheet (312), F1 is the equivalent concentrated force of the force acting on the inclined plate (3112) in the length direction of the piezoelectric sheet (312), F2 is the equivalent concentrated force of the force acting on the inclined plate (3112) in the thickness direction of the piezoelectric sheet (312), T1 is the component of the stress received by the piezoelectric sheet (312) in the length direction of the piezoelectric sheet (312), t p is the thickness of the piezoelectric sheet (312), l1 is the length of the bonding plate (3111); The calculation method for the power generation amount of the piezoelectric assembly (3) is: Calculate the length l of the cavity formed by the middle parts of the inclined plate (3112), the top plate (3113) and the piezoelectric sheet (312). c = 2l2cosθ + l3, where the total length l of the bonding plate (3111) b = 2l1, l2 is the length of the inclined plate (3112), and l3 is the length of the top plate (3113); Through force analysis, it can be obtained that the force acting on the bonding part along the thickness direction of the piezoelectric sheet (312) by the inclined plate (3112) can be equivalent to a concentrated force F3 acting in the width direction of the piezoelectric sheet (312), and the force acting on the bonding part along the length direction of the piezoelectric sheet (312) by the inclined plate (3112) can be equivalent to a concentrated force F4 acting in the length direction of the piezoelectric sheet (312). The moment acting on the inclined plate (3112) by the top plate (3113) is M1, and the moment acting on the inclined plate (3112) by the bonding plate (3111) is M2, and they satisfy: F2 = F4; M1 = 0, M2 = (F1cosθ - F2sinθ)l2; Moreover, define the deflection of the inclined plate (3112) as ω1, satisfying The boundary conditions are as follows: Among them, B s is the flexural rigidity of the metal pressing sheet (311), E m is the elastic modulus of the metal pressing sheet (311), and θ is the acute angle between the inclined plate (3112) and the piezoelectric sheet (312); Calculate the deflection ω1 of the inclined plate (3112): Then the deformation of the piezoelectric sheet (312) in its length direction satisfies: S1l c = 2ω1sinθ; Since there is no external electric field, calculate the equivalent concentrated force F2: Wherein, N is the pressure received by the metal pressing piece (311); Therefore, the power generation of the piezoelectric component (3) is the electric quantity Q generated by the pressure N g :

7. The distributed electric drive tire rotation energy collector according to claim 5, wherein The calculation method for the power generation amount of the electromagnetic assembly is: The radius of the induction coil (21) of the electromagnetic assembly is r, then the area surrounded by the induction coil (21) S＝πr 2 ； When the magnetic iron core (22) in the induction coil (21) moves outward under the repulsive force between the like-pole magnets of the permanent magnet (42) in the loading cam (4), the magnetic flux Φ of the magnetic iron core (22) in the induction coil (21) changes, and then an induced electromotive force E is generated. Establish a magnetic flux calculation model of the magnetic iron core (22) according to the included angle θ' between the magnetic field direction and the normal direction of the plane of the induction coil (21); Φ = BScosθ'; Use the magnetic flux calculation model to calculate the magnetic flux Φ1 at the maximum displacement of the magnetic iron core (22) under the repulsive displacement of the permanent magnet (42) and the magnetic flux Φ2 when the magnetic iron core (22) returns to the initial position, and use Φ1 and Φ2 to calculate the induced electromotive force E; ΔΦ = Φ2 - Φ1; Among them, B is the magnetic induction intensity of the magnetic iron core (22), n is the number of turns of the induction coil (21), is the change rate of magnetic flux, ΔΦ is the change amount of magnetic flux during the process of the magnetic iron core (22) from displacement to recovery, and Δt is the time taken for the magnetic iron core (22) to return to the initial position from the occurrence of displacement.

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