Magnetic suspension type variable barrier bistable energy collection device

Abstract

The utility model discloses a magnetic suspension type variable barrier bistable energy collection device which comprises a base, a sleeve, a first annular magnet, a second annular magnet, a suspension magnet, a coil and a third magnet. The two ends of the suspension magnet repel the corresponding first annular magnet and the second annular magnet respectively, the third magnet elastically reciprocates in the transverse direction relative to the coil, and the third magnet and the suspension magnet are consistent in magnetic pole direction. The two external third magnets are subjected to two-way deviation rectification through elastic arrangement, potential energy is dynamically reduced when the potential barrier returns to the balance position, the potential energy is enhanced when the potential barrier is far away from the balance position, and the purposes of dynamically reducing the return potential barrier and improving the outward stroke potential energy are achieved. Therefore, the technical effect of high-efficiency energy collection in low-frequency environment vibration is achieved, and the problems that a traditional energy collection device is fixed in potential barrier and low in energy conversion efficiency under the low-frequency vibration condition are solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to power supply field especially relates to a magnetic suspension formula variable potential barrier bistable energy collection device. BACKGROUND

[0002] Facing the challenge of energy shortage and environmental pollution, harvesting energy from environmental vibrations is a potential solution for powering wireless sensors and portable electronic devices. Generally, environmental vibrations are converted into electrical energy in the form of electrostatic, electromagnetic or piezoelectric effects. Linear vibration energy harvesters usually collect energy near the resonant frequency, with a narrow effective bandwidth, which is limited in real excitations. In the past decade, in order to improve the power and bandwidth of vibration energy harvesters, techniques such as parametric excitation, internal resonance, up-conversion, multiple degrees of freedom (modal), nonlinearity and their combinations have been adopted. Among them, the non-linear bistable energy harvester has attracted extensive attention from scholars at home and abroad. Experiments have proved that its output bandwidth is better than that of linear and non-linear monostable energy harvesters.

[0003] The conventional magnetic suspension bistable energy collection device is difficult to form inter-well motion under weak excitation, thereby resulting in a narrow output bandwidth, and the potential barrier well cannot be dynamically adjusted. Influenced by manufacturing and installation errors, variable strength or frequency excitation or other disturbances, the magnetic suspension bistable energy collection device may still be unable to break through the threshold to form inter-well motion. SUMMARY

[0004] The magnetic suspension variable potential barrier bistable energy collection device of the utility model is used to solve the technical problems in the background art.

[0005] The technical scheme provided by the utility model is as follows: a magnetic suspension variable potential barrier bistable energy collection device, comprising: a base, a sleeve vertically arranged on the base, a first annular magnet and a second annular magnet arranged at both ends in the sleeve, a suspension magnet placed between the first annular magnet and the second annular magnet, a coil sleeved outside the sleeve, and two third magnets oppositely arranged outside the sleeve.

[0006] The suspension magnet repels the corresponding first annular magnet and second annular magnet at both ends, and the third magnet elastically reciprocates in the transverse direction relative to the coil, and the magnetic pole direction of the third magnet is consistent with that of the suspension magnet.

[0007] The distance between the first annular magnet and the second annular magnet is adjustable, and the distance between the third magnet and the sleeve is adjustable.

[0008] In one embodiment, the first annular magnet is connected to the upper end cover, a plurality of first waist-shaped holes are formed in the circumferential direction at the upper side position of the sleeve, and the first waist-shaped holes are connected to the upper end cover through bolts.

[0009] In one embodiment, the second annular magnet is connected to the lower end cover, and a plurality of second waist-shaped holes are formed in the lower side of the sleeve in the circumferential direction, and the lower end cover is connected to the second waist-shaped holes through bolts.

[0010] In one embodiment, a buffer body is connected to the center of the suspension magnet, and the buffer body protrudes out of the suspension magnet at both ends.

[0011] In one embodiment, a support seat is connected to the base, and a third magnet is connected to the support seat; a third waist-shaped hole is formed in the base, and the support seat is connected to the third waist-shaped hole through fasteners.

[0012] In one embodiment, a guide rail is slidably connected to the support seat, and the end of the guide rail is connected to the third magnet; a spring is arranged between the guide rail and the support seat, and is used for the elastic reciprocating movement of the third magnet relative to the coil in the transverse direction.

[0013] In one embodiment, an annular groove is formed in the outer part of the sleeve towards the inside, and the coil is sleeved in the annular groove.

[0014] Compared with the prior art, the energy collection device has the following beneficial effects:

[0015] (1) The energy collection device adopts the mode of bidirectional deviation correction of two external third magnets through elasticity, and reduces the potential energy when returning to the balance position and enhances the potential energy when moving away from the balance position, so as to achieve the purposes of dynamically reducing the return potential barrier and increasing the outward stroke potential energy, thereby realizing the technical effect of high-efficiency energy collection in a low-frequency environmental vibration, and solving the problems of fixed potential barrier and low energy conversion efficiency of the traditional energy collection device under low-frequency vibration conditions. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a schematic diagram of the overall structure of the energy collection device of the utility model;

[0017] Figure 2 is a sectional view of the sleeve in the utility model;

[0018] Figure 3 is a principle structure diagram of the energy collection device of the utility model;

[0019] Figure 4 is a traditional magnetic suspension type bistable potential energy curve and a variable potential barrier bistable potential energy surface in the utility model;

[0020] Figure 5 is a comparison diagram of the output current of the energy collection device of the utility model.

[0021] The attached diagram is labeled as follows: 1. Base; 2. Sleeve; 3. First annular magnet; 4. Suspension magnet; 5. Second annular magnet; 6. Coil; 7. Third magnet; 8. Upper end cover; 9. First oblong hole; 10. Lower end cover; 11. Second oblong hole; 12. Buffer body; 13. Support base; 14. Third oblong hole; 15. Guide rail; 16. Spring; 17. Annular groove. Detailed Implementation

[0022] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0023] Example 1

[0024] like Figures 1-3 As shown, this utility model is a magnetically levitated variable potential barrier bistable energy harvesting device, including: a base 1, a sleeve 2, a first annular magnet 3, a levitation magnet 4, a second annular magnet 5, a coil 6, and two third magnets 7. The sleeve 2 is vertically connected to the base 1. The first annular magnet 3 and the second annular magnet 5 are respectively arranged at the upper and lower positions inside the sleeve 2. The levitation magnet 4 is suspended between the first annular magnet 3 and the second annular magnet 5. The coil 6 is sleeved in the middle position outside the sleeve 2. The two third magnets 7 are connected to the base 1 and are arranged horizontally relative to the coil 6, and elastically reciprocate in the horizontal direction. The distance between the first annular magnet 3 and the second annular magnet 5 is adjustable, and the distance between the third magnet 7 and the sleeve 2 is adjustable. Through the first annular magnet 3 and the second annular magnet 5... The system is configured such that the levitation magnet 4 is suspended within the sleeve 2 and has two static stable points; the two external third magnets 7, which reciprocate laterally, achieve the effect of a dynamic potential barrier trap; when the system is subjected to external vibration, the levitation magnet 4 moves axially within the sleeve 2, and the external coil 6 cuts the magnetic field lines to generate current, converting vibration energy into electrical energy; by using an elastic setting to bidirectionally correct the two external third magnets 7, the potential energy is dynamically reduced when the potential barrier returns to the equilibrium position and increased when it moves away from the equilibrium position, thus achieving the purpose of dynamically reducing the return potential barrier and increasing the outward potential energy. This achieves the technical effect of high-efficiency energy harvesting in low-frequency environmental vibration, thereby solving the problem of fixed potential barriers and low energy conversion efficiency in traditional energy harvesting devices under low-frequency vibration conditions.

[0025] In this embodiment, the first annular magnet 3 is connected to the lower end cover 8. The upper side of the sleeve 2 has multiple first waist-shaped holes 9 along the circumference. The upper end cover 8 is threaded and fixed by bolts passing through the first waist-shaped holes 9. The position adjustment of the upper end cover 8 and the first annular magnet 3 is achieved through the first waist-shaped holes 9.

[0026] In this embodiment, the second annular magnet 5 is connected to the lower end cover 10. The lower side of the sleeve 2 has a plurality of second waist-shaped holes 11 along the circumference. Bolts are threaded through the second waist-shaped holes 11 and fixed to the lower end cover 10. The position adjustment of the lower end cover 10 and the second annular magnet 5 is achieved through the second waist-shaped holes 11.

[0027] In this embodiment, a buffer body 12 is connected to the center of the levitation magnet 4. The buffer body 12 is made of a non-magnetic material, preferably rubber in this embodiment. Its two ends protrude from the levitation magnet 4 to buffer the levitation magnet 4 and prevent it from directly colliding with the first annular magnet 3 and the second annular magnet 5.

[0028] In this embodiment, a third oblong hole 14 is provided on the base 1, and a support seat 13 is connected to the third oblong hole 14 by fasteners. A third magnet 7 is connected to the support seat 13. The distance between the third magnet 7 and the sleeve 2 can be adjusted through the third oblong hole 14.

[0029] Furthermore, a guide rail 15 is slidably connected to the support base 13, and the end of the guide rail 15 is connected to the third magnet 7; a spring 16 is provided between the guide rail 15 and the support base 13 to realize the elastic reciprocating motion of the third magnet 7 relative to the coil 6 in the lateral direction.

[0030] In this embodiment, an annular groove 17 is formed on the outside of the sleeve 2, and the coil 6 is sleeved in the annular groove 17. The annular groove 17 is used to hold the coil 6, ensuring the stability of the coil 6 in the device and improving the stability of the device.

[0031] In this embodiment, as shown in the figure, the lower side of the first ring magnet 3 is the S pole, the upper side of the second ring magnet 5 is the N pole, the upper side of the levitation magnet 4 is the S pole, the lower side of the third magnet 7 is the S pole, and the lower side of the third magnet 7 is the S pole. The polarity configuration ensures that the levitation magnet 4 forms a magnetically levitated stable structure between the first ring magnet 3 and the second ring magnet 5. At the same time, the magnetic force of the external third magnet 7 in the lateral direction can provide a variable barrier bistable characteristic.

[0032] Working principle: When the system is subjected to external vibration, the suspending magnet 4 vibrates freely along the axial direction inside the sleeve 2. Due to the magnetic force of the first annular magnet 3 and the second annular magnet 5 on its upper and lower sides respectively, the suspending magnet 4 can move back and forth between two static stable points at a suitable distance.

[0033] Meanwhile, the two third magnets 7 are influenced by the magnetic field of the levitation magnet 4 in the lateral direction, and reciprocate elastically along the spring 16 on the guide rail 15. This dynamic change in the lateral magnetic field causes the potential barrier depth of the system to change during the motion: when the levitation magnet 4 approaches the equilibrium position, the potential barrier becomes shallower, facilitating its continued movement; while when it moves away from the equilibrium position, the potential barrier becomes deeper, increasing the potential energy storage capacity. This characteristic helps to improve the energy conversion efficiency under low-frequency vibration environments.

[0034] Furthermore, since coil 6 is fitted in the middle of sleeve 2, when the levitation magnet 4 moves axially, its magnetic flux changes accordingly, causing the magnetic field lines in coil 6 to be cut, generating an induced current. This induced current can be stored through rectification and energy storage circuits or used for direct power supply, thereby achieving efficient collection of low-frequency environmental vibration energy.

[0035] Example 2

[0036] The potential energy function and governing equations of the magnetically levitated variable barrier bistable energy harvesting device are determined by the following calculation steps:

[0037] (1) First, the magnetic induction intensity produced by the first ring magnet, the second ring magnet, and the outer magnet on the levitation magnet is calculated using the Biot-Savart law. The magnetic induction intensity produced by magnet B (third magnet 7) on magnet A (levitation magnet 4) is (Equation 1):

[0038]

[0039] (2) Calculate the magnetic potential energy, r B The magnetic field generated by the magnet at point r affects the magnetic field at point r. A The potential energy of the magnet at that location is (Equation 2):

[0040] U m =-m P ·B BA

[0041] (3) Calculate the elastic potential energy (Equation 3):

[0042]

[0043] like Figure 3 As shown, the interaction between the central oscillating magnet and the external fixed magnet is explained using the magnetic dipole model, including the interaction force between the magnets and the potential energy function. The magnetic induction intensity produced by magnet B on magnet A is:

[0044]

[0045] Where ▽ and |||2 represent the gradient operator and the 2-norm, respectively. BA =r B -rA It is a vector representing the distance r from the magnetic moment source of B to the magnetic moment source of A. BA This refers to the distance between two magnets. Located at r B The magnetic moment of the source magnet at that location is determined by m B =M B V B Given, where M B and V B These are the magnetization intensity and volume of the source magnet, respectively. In r B The magnetic field generated by the magnet at point r affects the magnetic field at point r. A The potential energy of the magnet at that location is:

[0046] U m =-m P ·B BA

[0047] Where m P It is located at r A The magnetic moment of the magnet is obtained. The potential energy of the central magnet due to its interaction with the other four magnets can be obtained using equations (1) and (2). For ease of calculation, we introduce parameters d, V0, and V. t Let's define the volumes of the central oscillating magnet, the two outer magnets, and the upper and lower magnets, respectively. The corresponding magnetization of these magnets is determined by M. C M0 and M t Defined, its subscript matches the subscript of the magnet volume. d is the half-space between the top and bottom magnets, such as... Figure 3 As shown, the expression for magnetic potential energy is therefore:

[0048]

[0049] Where y = y1 - y0 is the relative position of the central magnet with respect to the outer casing of the device. Since the variable barrier energy harvesting device contains a spring-loaded magnetic oscillator, elastic potential energy also exists.

[0050]

[0051] The total potential energy of the system is:

[0052]

[0053] The expression for the restoring force is obtained from the derivative of the potential energy with respect to y:

[0054]

[0055] Let X b =0 yields the expressions for the potential energy function and restoring force of a traditional magnetically levitated bistable energy harvester.

[0056]

[0057]

[0058] like Figure 3 As shown, the control equations for a variable barrier energy generator that directly supplies power to a resistive load are given by the following equation:

[0059]

[0060] Where m is the mass of the central magnet, c is a constant describing mechanical dissipation, z is the acceleration of the external excitation, I is the current, and L is the inductance of the coil. It is the natural frequency of the spring magnet.

[0061] Similarly, the governing equations for a traditional magnetically levitated bistable vibration energy harvesting device are as follows:

[0062]

[0063] Based on the theoretical model above, the potential energy function of the magnetically levitated variable barrier bistable energy harvesting device is a multivariate function, which can be expressed as:

[0064] U = U m +E p

[0065] In the formula U m For magnetic potential energy, E p For elastic potential energy, U m and E p In this context, M, y, and R0 are structural constant parameters, and y and x are... b These are time-varying parameters.

[0066] like Figure 4 As shown, it is a displacement y and an external magnet displacement x. b A bivariate function. An asymmetric saddle surface is formed at y = 0, and as the displacement x... b As the value changes from negative to positive, the peak of the saddle surface gradually flattens. In x... b The potential energy surface at point 0 becomes the potential energy curve of a conventional bistable system energy harvesting device with a fixed potential barrier, and its curve is as follows: Figure 4 The magenta curve in the figure shows that the device needs to overcome an extremely high potential barrier to form inter-well motion (high-energy orbit). Conversely, the BEH-DB flows downward from the high-energy point to the potential valley, and then crosses a relatively flat saddle surface downstream, easily forming larger inter-well oscillations, as shown by the red curve in the figure. The results show that, at the same excitation energy level, the magnetically levitated variable-barrier bistable energy harvesting device is more likely to escape from the well and achieve an inter-well orbit than the conventional magnetically levitated bistable energy harvesting device, thanks to the variable-barrier effect.

[0067] Broadening the frequency range of energy harvesting devices is of considerable significance in energy harvesting. To gain a deeper understanding of the ability of energy harvesting devices to achieve this goal, numerical simulations of the system were performed. The generated currents of a traditional magnetically levitated bistable energy harvester and a magnetically levitated variable-barrier bistable energy harvester were compared through numerical frequency sweeping. The excitation form of the sweep is as follows: Where A is the acceleration, Ω0 is the initial frequency, and Ω r The sweep rate is 0.05 Hz / s.

[0068] Figure 5 This represents the output current magnitudes of a traditional magnetically levitated bistable energy harvester and a magnetically levitated variable-barrier bistable energy harvester at excitation values ​​of A = 5 m / s² and A = 10 m / s². To quantitatively compare the output current capabilities of the two models, the effective bandwidth is simply defined as an absolute current greater than or equal to 6 mA. When the excitation amplitude is relatively small at 5 m / s², the effective bandwidth of the variable-barrier bistable energy harvester is approximately 3.3 Hz (5.2-8.5 Hz), while the effective bandwidth of the traditional magnetically levitated bistable energy harvester is approximately 0.4 Hz (13.2-13.6 Hz), about 1 / 8 of that of the variable-barrier bistable energy harvester. At an excitation value of 15 m / s², the effective bandwidth of the variable-barrier bistable energy harvester is the widest, approximately 9.5 Hz (3.5-13 Hz), which is 8.5 times that of the traditional magnetically levitated bistable energy harvester. Therefore, regardless of whether the excitation is small or large, the effective bandwidth of the variable barrier bistable energy harvesting device is wider than that of the magnetic levitation bistable energy harvesting device. Furthermore, the variable barrier bistable energy harvesting device is easier to harvest energy at low frequencies than the magnetic levitation bistable energy harvesting device, and the total current harvested is also greater than that of the CBEH.

[0069] Figure 5 In the diagram, (a) represents the output current of the variable-barrier bistable energy harvesting device during a forward frequency sweep with an excitation amplitude A = 5 m / s². (b) represents the output current of a conventional bistable energy harvesting device during a forward frequency sweep with an excitation amplitude A = 5 m / s². (c) represents the output current of the variable-barrier bistable energy harvesting device during a forward frequency sweep with an excitation amplitude A = 10 m / s². (d) represents the output current of a conventional bistable energy harvesting device during a forward frequency sweep with an excitation amplitude A = 10 m / s². The sweep rate Ωr = 0.05 Hz / s.

[0070] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing the present invention and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0071] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A magnetically levitated variable barrier bistable energy harvesting device, characterized in that, include: The base (1), the sleeve (2) vertically arranged on the base (1), the first annular magnet (3) and the second annular magnet (5) arranged at both ends inside the sleeve (2), the suspending magnet (4) placed between the first annular magnet (3) and the second annular magnet (5), the coil (6) sleeved outside the sleeve (2), and the two third magnets (7) arranged opposite to each other outside the sleeve (2); The two ends of the levitation magnet (4) repel the corresponding first ring magnet (3) and second ring magnet (5) respectively. The third magnet (7) reciprocates elastically in the lateral direction relative to the coil (6). The magnetic pole direction of the third magnet (7) is consistent with that of the levitation magnet (4). The distance between the first annular magnet (3) and the second annular magnet (5) is adjustable, and the distance between the third magnet (7) and the sleeve (2) is adjustable.

2. The magnetically levitated variable potential barrier bistable energy harvesting device as described in claim 1, characterized in that, The first annular magnet (3) is connected to the upper end cover (8). The upper side of the sleeve (2) is provided with a plurality of first waist-shaped holes (9) along the circumferential direction. The first waist-shaped holes (9) are connected to the upper end cover (8) by bolts.

3. The magnetically levitated variable potential barrier bistable energy harvesting device as described in claim 1, characterized in that, The second annular magnet (5) is connected to the lower end cover (10). The lower side of the sleeve (2) is provided with a plurality of second waist-shaped holes (11) along the circumferential direction. The lower end cover (10) is connected to the second waist-shaped holes (11) by bolts.

4. The magnetically levitated variable barrier bistable energy harvesting device as described in claim 1, characterized in that, A buffer body (12) is connected to the center of the levitation magnet (4), and the two ends of the buffer body (12) protrude from the levitation magnet (4).

5. The magnetically levitated variable potential barrier bistable energy harvesting device as described in claim 1, characterized in that, The base (1) is connected to a support seat (13), and the support seat (13) is connected to the third magnet (7); the base (1) has a third waist-shaped hole (14), and the support seat (13) is connected to the third waist-shaped hole (14) by fasteners.

6. The magnetically levitated variable potential barrier bistable energy harvesting device as described in claim 5, characterized in that, A guide rail (15) is slidably connected to the support base (13), and the end of the guide rail (15) is connected to the third magnet (7); a spring (16) is provided between the guide rail (15) and the support base (13) for the elastic reciprocating motion of the third magnet (7) relative to the coil (6) in the lateral direction.

7. The magnetically levitated variable barrier bistable energy harvesting device as described in claim 1, characterized in that, The sleeve (2) has an annular groove (17) on its outside and inward, and the coil (6) is sleeved in the annular groove (17).

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