A vibration sensing isolator

Abstract

This invention discloses a vibration-sensing isolator, comprising a magnetic field generating structure (1), a magnetorheological fluid variable damping structure (2) driven by a compressive-torsional metamaterial, a magnetorheological elastomer variable stiffness structure (3), and a triboelectric nanogenerator vibration sensor structure (4). The magnetic field generating structure (1) is fitted outside the magnetorheological fluid variable damping structure (2), the magnetorheological elastomer variable stiffness structure (3) is placed inside the magnetorheological fluid variable damping structure (2), and the triboelectric nanogenerator vibration sensor structure (4) is fitted onto the magnetorheological fluid variable damping structure (2). The magnetic field generating structure (1) is used to generate a magnetic field parallel to the rotation axis, the magnetorheological fluid variable damping structure (2) is used to provide adjustable damping, the magnetorheological elastomer variable stiffness structure (3) is used to provide variable stiffness, and the triboelectric nanogenerator vibration sensor structure (4) is used to sense vibration through self-generated power. The vibration-sensing isolator of this invention has accurate vibration sensing, good vibration isolation effect, and long service life.

Description

Technical Field

[0001] This invention belongs to the field of intelligent vibration isolation, specifically a vibration sensing isolator based on magnetorheological effect and compressive-torsional metamaterial. Background Technology

[0002] Vibration isolation refers to installing elastic materials or devices between the vibration source and the vibrating object, such as equipment foundation or the surrounding environment, to reduce the vibration energy transmitted from the vibration source to the vibrating object, thereby achieving effective control of vibration and reducing the interference caused by external vibration to the vibrating object.

[0003] Semi-active vibration-sensing isolators utilize smart materials or controllers to adjust the stiffness and damping of the isolator through vibration sensing, thereby changing the isolator's natural frequency and peak acceleration to reduce vibration. This method saves energy compared to active vibration isolation and has a better vibration isolation effect than passive vibration isolation. A common vibration-sensing isolator, as described in reference 1 (Li R, Gou X, Zhou M, et al. Modeling and validation of multifield coupled self-sensing characteristics of magnetorheological elastomer for vibration isolators[J]. Materials & Design, 2022, 217: 110636.), consists of a magnetorheological elastomer with piezoresistive effect and a magnetic field generating structure. When the magnetorheological elastomer is subjected to external force, its resistance changes. When the external vibration is large, the pressure on the magnetorheological elastomer inside the isolator increases, resulting in a decrease in its resistance, thus realizing the vibration sensing function. Furthermore, by changing the magnetic field, the stiffness of the magnetorheological elastomer is adjusted, thereby achieving vibration isolation. This type of vibration isolator adjusts the natural frequency by changing the stiffness of the magnetorheological elastomer. This may result in a larger vibration amplitude at the natural frequency after isolation compared to the unisolated natural frequency, as described in reference 2 (Zhu Z, Wei R, Zhang H, et al. Cat paw-inspired magnetorheological elastomer embedded mechanical metamaterials with active sensing and switching stiffness for vibration isolator[J]. Sustainable Materials and Technologies, 2024, 40:e954.). This is because the isolator does not effectively adjust the damping, resulting in ineffective dissipation of the energy generated by vibration. While this vibration-sensing isolator can detect vibration, the resistance of the magnetorheological elastomer is affected not only by external forces but also by magnetic fields. Since the magnetorheological elastomer is simultaneously affected by magnetic fields and external pressure, the change in resistance when a magnetic field is applied cannot be linearly related to the pressure, thus failing to accurately reflect external vibration information. Secondly, this sensing method requires an external power source to power the magnetorheological elastomer, which cannot enable long-term autonomous monitoring of the vibration isolator.

[0004] In summary, the problems with existing technologies are: vibration-sensing isolators have poor vibration isolation effects, inaccurate vibration sensing, and short service life. Summary of the Invention

[0005] The purpose of this invention is to provide a vibration-sensing isolator that has good vibration isolation effect, accurate vibration sensing, and long service life.

[0006] The technical solution to achieve the purpose of this invention is as follows:

[0007] A vibration-sensing isolator includes a cylindrical magnetic field generating structure that is generally closed at both ends, a cylindrical magnetorheological fluid variable damping structure driven by a torsion metamaterial that is also generally closed at both ends, a generally cylindrical magnetorheological elastomer variable stiffness structure, and a generally annular triboelectric nanogenerator vibration sensor structure. The magnetic field generating structure is mounted outside the magnetorheological fluid variable damping structure, the magnetorheological elastomer variable stiffness structure is placed inside the magnetorheological fluid variable damping structure, and the triboelectric nanogenerator vibration sensor structure is mounted on the magnetorheological fluid variable damping structure. The rotation axes of the magnetic field generating structure, the magnetorheological fluid variable damping structure, the magnetorheological elastomer variable stiffness structure, and the triboelectric nanogenerator vibration sensor structure coincide. The magnetic field generating structure is used to generate a magnetic field parallel to the rotation axis, the magnetorheological fluid variable damping structure is used to provide adjustable damping, the magnetorheological elastomer variable stiffness structure is used to provide variable stiffness, and the triboelectric nanogenerator vibration sensor structure is used to sense vibrations through self-generated power.

[0008] The significant advantages of this invention compared to existing technologies are:

[0009] 1. Excellent vibration isolation effect: This invention uses a rotating magnetorheological fluid damper with added needle roller bearings to improve the variable damping performance per unit volume. At the same time, a compressive-torsional metamaterial is added to drive its movement to generate rotational damping. Combined with a magnetorheological elastomer, the stiffness and damping can be adjusted synchronously when a magnetic field is applied, which improves the vibration isolation effect. This overcomes the shortcomings of existing vibration isolators that only adjust stiffness and ignore damping, resulting in the failure to effectively dissipate the energy generated by vibration and poor vibration isolation effect.

[0010] 2. Accurate vibration sensing: The triboelectric nanogenerator is unaffected by external factors such as magnetic fields; the generated voltage is only related to the vibration amplitude during the vibration process, resulting in accurate vibration sensing. This overcomes the drawback of magnetorheological elastomers, where the resistance change is simultaneously affected by external forces and applied magnetic fields.

[0011] 3. Long service life: This invention uses contact blocks (made by demolding Ecoflex) and pressure-torsion metamaterials (coated with nitrile) inside the vibration isolator to form a set of triboelectric nanogenerators, which can generate voltage signal output without the need for external power supply, thus overcoming the disadvantage of existing vibration sensing isolators that require external power supply for sensing function. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the external structure of the vibration sensing isolator of the present invention.

[0013] Figure 2 This is a schematic diagram of the internal structure of the vibration sensing isolator of the present invention.

[0014] Figure 3 for Figure 2 A schematic diagram of the structure that generates a medium magnetic field.

[0015] Figure 4 for Figure 1 A schematic diagram of the external structure of a magnetorheological fluid variable damping structure driven by a medium-pressure torsion metamaterial.

[0016] Figure 5 for Figure 2 A magnified view of a magnetorheological fluid variable damping structure driven by a medium-pressure torsion metamaterial.

[0017] Figure 6 for Figure 2 A magnified view of a variable stiffness structure of a magnetorheological elastomer.

[0018] Figure 7 for Figure 2 A magnified view of a vibration sensor for a triboelectric nanogenerator.

[0019] Figure 8 This is a schematic diagram showing the relationship between static pressure and displacement curves in a tension-compression testing machine for a magnetorheological elastomer vibration isolator.

[0020] Figure 9 A schematic diagram showing the relationship between static pressure and displacement curves in a tension-compression testing machine for vibration-sensing isolators.

[0021] Figure 10 This is a schematic diagram of the frequency shift characteristics and peak acceleration experimental results of the vibration sensing isolator.

[0022] Figure 11 This is a schematic diagram illustrating the principle of voltage signal generation in a triboelectric nanogenerator.

[0023] In the picture:

[0024] 1. Magnetic field generating structure; 2. Magnetorheological fluid variable damping structure driven by compressive-torsional metamaterials; 3. Magnetorheological elastomer variable stiffness structure; 4. Triboelectric nanogenerator vibration sensor structure.

[0025] 101 Lower magnetic housing, 102 Lower magnetic core, 103 Copper coil, 104 Coil hub, 105 Magnetic housing, 106 Upper magnetic core, 107 Upper magnetic housing

[0026] 201 Limiting sleeve, 202 Upper connecting cover, 203 Torsion interlayer, 204 Compression-torsion metamaterial (coated with nitrile), 205 Lower cover, 206 Lower connector, 207 Inner sealing ring, 208 Outer sealing ring, 209 Flat thrust needle roller bearing, 210 Magnetorheological fluid, 211 Base

[0027] 301 Lower magnetic conductor block, 302 Upper magnetic conductor block, 303 Magnetorheological elastic body

[0028] 401 contact block, 402 copper electrode. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0030] like Figure 1 , 2 As shown, the vibration sensing isolator of the present invention includes a magnetic field generating structure 1, a magnetorheological fluid variable damping structure 2 driven by a compressive-torsional metamaterial, a magnetorheological elastomer variable stiffness structure 3, and a triboelectric nanogenerator vibration sensor structure 4.

[0031] The magnetic field generating structure 1 is a cylindrical shape that is roughly closed at both ends, and the magnetorheological fluid variable damping structure 2 is a cylindrical shape that is roughly closed at both ends; the magnetic field generating structure 1 is fitted outside the magnetorheological fluid variable damping structure 2.

[0032] The magnetorheological elastomer variable stiffness structure 3 is roughly cylindrical and is placed inside the magnetorheological fluid variable damping structure 2.

[0033] The triboelectric nanogenerator vibration sensor structure 4 is roughly ring-shaped and is mounted on the magnetorheological fluid damping structure 2.

[0034] The rotation axes of the magnetic field generating structure 1, the magnetorheological fluid variable damping structure 2, the magnetorheological elastomer variable stiffness structure 3, and the triboelectric nanogenerator vibration sensor structure 4 coincide.

[0035] The magnetic field generating structure 1 is used to generate a magnetic field parallel to the rotation axis.

[0036] The magnetorheological fluid variable damping structure 2 is used to provide adjustable damping.

[0037] The magnetorheological elastomer variable stiffness structure 3 is used to provide variable stiffness.

[0038] The triboelectric nanogenerator vibration sensor structure 4 is used to sense vibrations through self-generated electricity.

[0039] The vibration-sensing isolator is placed between the vibration source and the vibrating object. When the vibration source vibrates, the magnetic field generating structure 1 generates a magnetic field parallel to the rotation axis by applying an external current. The triboelectric nanogenerator vibration sensor structure 4 senses the vibration, including amplitude and frequency. The magnetorheological elastomer variable stiffness structure 3 adjusts its own stiffness according to the sensed vibration, and the magnetorheological fluid variable damping structure 2 adjusts its own damping according to the sensed vibration. Therefore, the vibration-sensing isolator can not only accurately sense the vibration of the vibration source, but also provide different stiffness and damping required for vibration isolation according to different amplitudes and frequencies of vibration, so that the vibrating object achieves excellent vibration isolation effect. At the same time, the triboelectric nanogenerator vibration sensor structure 4 generates electricity through electrostatic induction and contact electrification, and senses vibration through self-generated electricity. It not only senses vibration accurately, but also has a long service life.

[0040] like Figure 3 As shown, the magnetic field generating structure 1 includes an annular lower magnetic housing 101, a cylindrical lower magnetic core 102, a cylindrical copper coil 103, a cylindrical coil hub 104 with grooves on its outer periphery, a cylindrical magnetic housing 105, an upper magnetic core 106 formed by connecting two cylindrical sections that are larger at the top and smaller at the bottom, and an annular upper magnetic housing 107.

[0041] The copper coil 103 is fitted into the groove on the outer periphery of the coil hub 104, and the magnetic housing 105 is fitted onto the outside of the coil hub 104;

[0042] The upper end of the magnetic housing 105 is detachably and fixedly connected to the outer edge of the upper magnetic housing 107, and its lower end is detachably and fixedly connected to the outer edge of the lower magnetic housing 101. The upper end of the coil hub 104 abuts against the lower surface of the upper magnetic housing 107, and the lower end of the coil hub 104 abuts against the upper surface of the lower magnetic housing 101.

[0043] The lower magnetic core 102 is loosely fitted inside the coil hub 104, and its lower surface abuts against the lower magnetic housing 101.

[0044] The upper magnetic core 106 is loosely fitted inside the coil hub 104, with its upper part passing through the central hole of the upper magnetic housing 107 and its upper end being flush with the upper surface of the upper magnetic housing 107.

[0045] After the copper coil 103 is connected to an external power source, it generates a uniform magnetic field parallel to the axis of rotation in the space formed by the lower magnetic housing 101, the magnetic housing 105, the upper magnetic housing 107, the lower magnetic core 102, and the upper magnetic core 106.

[0046] like Figure 4 , 5 As shown, the magnetorheological fluid damping structure 2 includes a cylindrical limiting sleeve 201; the upper periphery of the limiting sleeve 201 is uniformly provided with multiple axial guide grooves.

[0047] It also includes an upper connecting cover 202, a lower cover 205, and a base 211. The upper connecting cover 202 is mainly disc-shaped, and has multiple guide blocks in the radial direction around its periphery that match the guide groove of the limiting sleeve 201. The upper connecting cover 202 can move up and down along the axial direction.

[0048] The lower cover 205 is annular, and the base 211 is approximately cylindrical. The upper surface of the lower cover 205 is fixedly connected to the lower end of the limiting sleeve 201, and the lower surface of the lower cover 205 is fixedly connected to the upper surface of the base 211.

[0049] Preferably, the upper surface of the lower cover 205 is bonded to the lower end of the limiting sleeve 201 with adhesive.

[0050] Preferably, the lower surface of the lower cover 205 is bonded to the upper surface of the base 211 with adhesive.

[0051] The lower cover 205 is fixedly connected to the limiting sleeve 201 and the base 211 with glue. This facilitates quick assembly and eliminates the need for drilling of the components, reducing the number of steps and making it easier for mass production.

[0052] The magnetorheological fluid damping structure 2 also includes a torsion sandwich 203, a compression-torsion metamaterial 204, a lower connector 206, and a planar thrust needle roller bearing 209.

[0053] The lower connector 206 is generally annular in shape, with an outer annular protrusion on the edge for placing the planar thrust needle roller bearing 209, which is annular in shape.

[0054] The twisted interlayer 203 is a cylinder with its lower end fixed and its upper end twisted into a spiral shape. The upper end is fixedly connected to the upper connecting cover 202, and the lower end is fixedly connected to the lower connecting piece 206.

[0055] The compression-torsion metamaterial 204 includes multiple circumferentially distributed inclined rods. The upper end of each inclined rod is fixedly connected to the upper connecting cover 202, and the lower end is fixedly connected to the lower connecting member 206. The projection point of the upper end of the inclined rod on the lower connecting member 206 is located at the front end of the same circumference of the lower end of the inclined rod in the direction of rotation.

[0056] The upper surface of the base 211 has an inner ring protrusion in the middle for placing the magnetorheological elastomer variable stiffness structure 3. The upper surface of the base 211 has an outer ring protrusion at the edge. The lower surface of the base 211 is fixedly connected to the lower magnetic core 101 of the magnetic field generating structure 1.

[0057] After the lower plane of the lower connector 206 is fixedly connected to the upper surface of the planar thrust needle roller bearing 209, it is fitted between the inner and outer annular protrusions on the upper surface of the base 211. An inner sealing ring 207 is provided between the inner circumferential surface of the lower connector 206 and the outer circumferential surface of the inner annular protrusion on the upper surface of the base 211, and an outer sealing ring 208 is provided between the outer circumferential surface of the lower connector 206 and the outer annular protrusion on the upper surface of the base 211.

[0058] The planar thrust needle roller bearing 209 is filled with magnetorheological fluid 210.

[0059] When the upper connecting cover 202 is subjected to an axial force toward the lower connecting piece 206 and moves downward along the guide groove under the guidance of the guide block, the upper end of the torsion interlayer 203 exhibits axial movement, while the lower end generates circumferential rotational movement. The upper end of the compression-torsion metamaterial 204 exhibits axial movement, while the lower end generates circumferential rotational movement, driving the planar thrust needle roller bearing 209 to rotate. This transforms the axial movement of the torsion interlayer 203 and the compression-torsion metamaterial 204 into the rotational movement of the planar thrust needle roller bearing 209, thereby driving the magnetorheological fluid 210 to move and generating variable damping under the action of the magnetic field.

[0060] The upper end of the torsion interlayer 203 is bonded to the upper connecting cover 202 with adhesive, and the lower end of the torsion interlayer 203 is bonded to the lower connecting piece 206 with adhesive.

[0061] The upper end of the pressure-twisting supermaterial 204 is fixedly connected to the upper connecting cover 202 with glue, and the lower end of the pressure-twisting supermaterial 204 is fixedly bonded to the lower connecting piece 206 with glue.

[0062] The bottom of the base 211 is fixed to the upper surface of the lower magnetic core 101 of the magnetic field generating structure 1 with glue, and the top of the coaxial connecting cover is fixed to the upper magnetic core 106 of the magnetic field generating structure 1 with glue, and is coaxial.

[0063] The compression-torsion metamaterial 204 is generated using an FDM printer, which has the advantages of fast printing and a wide selection of matrix materials.

[0064] The initial included angle β between the inclined rod of the compression-torsion metamaterial 204 and the lower connector 206 ranges from 55° to 85°. The range is determined based on the 3D printing effect and the magnitude of the driving force that the compression-torsion metamaterial 204 can provide.

[0065] The 216 flat thrust needle roller bearing uses standard parts, which has the advantages of being inexpensive and easy to replace.

[0066] The torsional sandwich structure 203 is prepared by curing and demolding a magnetorheological elastomer, which combines the good vibration isolation performance of the magnetorheological elastomer with the good vibration isolation performance of the torsional structure itself.

[0067] Magnetorheological fluid 210 is prepared by heating and stirring choline chloride and glycerol in a molar ratio of 1:2 until homogeneous, and then adding 60% carbonyl iron powder by mass and stirring until homogeneous.

[0068] like Figure 6 As shown, the magnetorheological elastomer variable stiffness structure 3 includes a cylindrical lower magnetic conductor block 301, a cylindrical upper magnetic conductor block 302, and a single-leaf hyperboloid magnetorheological elastomer 303.

[0069] The bottom of the magnetorheological elastomer 303 is fixedly connected to the upper end of the lower magnetic block 301, and the top of the magnetorheological elastomer 303 is fixedly connected to the lower end of the upper magnetic block 302.

[0070] The lower magnetic block 301 is fixedly placed inside the inner annular protrusion in the middle of the upper surface of the base 211. The upper end of the upper magnetic block 302 is fixedly connected to the lower surface of the upper connecting cover 202.

[0071] The magnetorheological elastic body 303 of the magnetorheological elastic body variable stiffness structure 3 is fixedly connected to the lower magnetic block 301, and the top of the magnetorheological elastic body 303 is fixedly connected to the upper magnetic block 302.

[0072] The bottom of the magnetorheological elastomer 303 is fixedly bonded to the lower magnetic block 301 using silicone rubber.

[0073] The top of the magnetorheological elastomer 303 is fixedly bonded to the upper magnetic block 302 using silicone rubber.

[0074] Silicone rubber is used to fix the magnetorheological elastomer 303 to the lower magnetic block 301 and the upper magnetic block 302. This facilitates quick assembly, and the good elasticity of silicone rubber allows the magnetorheological elastomer 303 to have good deformation capacity at the fixed connection point during movement. The upper magnetic block 302 of the magnetorheological elastomer variable stiffness structure 3 is fixed to the upper connecting cover 202 of the magnetorheological fluid variable damping structure 2 driven by the compressive-torsional metamaterial using glue, and the lower magnetic block 301 is fixed to the base 211 using glue.

[0075] When the magnetorheological elastomer variable stiffness structure 3 is subjected to an external force, the magnetorheological elastomer 303 undergoes elastic deformation along the axial direction. At this time, the stiffness of the magnetorheological elastomer 303 does not change. When the excitation frequency of the vibration source is the natural frequency of the vibrating object, the stiffness of the magnetorheological elastomer 303 changes under the action of the magnetic field, providing variable stiffness.

[0076] like Figure 7 As shown, the triboelectric nanogenerator vibration sensor structure 4 includes a plurality of contact blocks 401 distributed circumferentially along the lower surface of the upper connecting cover 202, wherein one end of each contact block 401 is flush with the other end and is hook-shaped. It also includes copper electrodes 402 with lead-out ends.

[0077] Each contact block 401 has a hook-shaped end that contacts the upper side of a pressure-torsion supermaterial 204 inclined rod, and the other end that contacts the upper side of the adjacent pressure-torsion supermaterial 204 inclined rod. Its upper surface is fixedly connected to the upper connecting cover 202. The copper electrode 402 is wrapped around the outside of all contact blocks 401 in a ring shape, and its upper edge is fixedly connected to the upper connecting cover 202.

[0078] The contact block 401 is integrally molded from silicone material Ecoflex material, and the contact area between the pressure-torsion super material 204 and the contact block 401 is coated with nitrile material.

[0079] The number of contact blocks 401 is the same as the number of inclined rods of the compression-torsion metamaterial 204.

[0080] The number of guide grooves on the upper part of the limiting sleeve 201 is the same as the number of contact blocks 401.

[0081] Preferably, there are 8 contact blocks 401.

[0082] The contact block (prepared by demolding Ecoflex) 401 and the pressure-torsion metamaterial (coated with nitrile) 204 together constitute a set of triboelectric nanogenerators. Nitrile, as an electropositive material, and Ecoflex, as an electronegative material, can generate contact separation motion under vibration environment to generate voltage signals. The voltage signals are extracted using copper electrodes 402.

[0083] The working principle of the vibration sensing isolator of this invention is as follows:

[0084] When the vibration source vibrates, the magnetic field generating structure 1 generates a magnetic field parallel to the rotation axis by applying an external current. The contact separation motion of the contact block 401 and the pressure-torsion metamaterial 204 in the triboelectric nanogenerator vibration sensor structure 4 generates a voltage signal to sense the vibration, including amplitude and frequency. The magnetorheological elastomer 303 in the magnetorheological elastomer variable stiffness structure 3 adjusts its stiffness according to the sensed vibration, and the magnetorheological fluid 210 in the pressure-torsion metamaterial-driven magnetorheological fluid variable damping structure 2 adjusts its viscosity according to the sensed vibration, which is then converted into adjustable damping by the pressure-torsion metamaterial 204. The magnetorheological elastomer variable stiffness structure 3 and the magnetorheological fluid variable damping structure 2 can provide different stiffness and damping required for vibration isolation according to different amplitudes and frequencies of vibration, enabling the vibrated object to achieve excellent vibration isolation. Simultaneously, the triboelectric nanogenerator vibration sensor structure 4 generates electricity through electrostatic induction and contact electrification, sensing vibration through self-generated power. This not only ensures accurate vibration sensing but also has a long service life.

[0085] Figure 8 This is a schematic diagram showing the relationship between static pressure and displacement curves in a tension / compression testing machine for magnetorheological elastomer vibration isolators. Figure 9This is a schematic diagram showing the relationship between static pressure and displacement curves in a vibration-sensing isolator tension-compression testing machine.

[0086] Figure 8 This paper introduces the relationship between force and displacement of a traditional magnetorheological elastomer (MEE) vibration isolator when different currents (i.e., different magnetic fields) are applied. The figure shows that as the applied magnetic field increases, the force on the MEE increases when it moves the same displacement. Analysis indicates that the static stiffness of the MEE increases (the slope of the curve). However, the area enclosed by the force-displacement curve does not change significantly with increasing magnetic field, indicating that the damping change is minimal. This suggests that traditional MEE vibration isolators primarily utilize variable stiffness for vibration isolation, with minimal damping variation.

[0087] Figure 9 This paper describes the relationship between the force and displacement of the vibration-sensing isolator of the present invention when different currents (i.e., different magnetic fields) are applied. The figure shows that as the applied magnetic field increases, the force that the isolator can withstand increases when it moves the same displacement. This indicates that the static stiffness of the isolator increases (the slope of the curve). As the applied magnetic field increases, the area enclosed by the force-displacement curve also increases, indicating a significant change in damping. This demonstrates that the vibration-sensing isolator of the present invention utilizes variable stiffness and variable damping for vibration isolation.

[0088] Figure 10 This is a schematic diagram of the experimental results of the frequency shift characteristics and peak acceleration of the vibration sensing isolator.

[0089] Figure 10 This paper introduces the relationship between the acceleration amplitude and frequency of a vibrating object measured by a vibration-sensing isolator under the sweep frequency action of a vibration source. The point where the acceleration amplitude is maximum corresponds to the natural frequency of the vibrating object. As shown in the figure, when different currents (i.e., different magnetic fields) are applied to the vibration-sensing isolator, the natural frequency of the vibrating object shifts to the right, from a minimum of 20.4 Hz to a maximum of 28.8 Hz. The acceleration amplitude at the natural frequency also increases from a maximum of 2.82 m / s². 2 It reached 2.23 m / s 2 The natural frequency shifts to the right because the stiffness of the magnetorheological elastomer variable stiffness structure 3 increases. The acceleration amplitude at the natural frequency decreases after the frequency shift because the variable damping effect of the magnetorheological fluid variable damping structure 2 driven by the compressive-torsional metamaterial enhances the dissipation of vibration energy.

[0090] Figure 11To explain the voltage signal generation principle of the triboelectric nanogenerator, multiple contact blocks (made by Ecoflex demolding) 401 and a pressure-torsion metamaterial (coated with nitrile) 204 together constitute a triboelectric nanogenerator. It can generate contact separation motion under vibration environment to generate voltage signal. The voltage signal is linearly related to the vibration and does not require an external power supply.

[0091] In summary, this invention provides a vibration-sensing isolator that achieves the effects of simultaneously adjustable stiffness and damping, a sensing function output voltage that is linearly related to vibration, and a sensing function that does not require external power supply. This solves the problems of poor vibration isolation effect, inaccurate vibration sensing, and short service life in existing technologies.

Claims

1. A vibration-sensing isolator, characterized in that: The structures include a cylindrical magnetic field generating structure (1) that is roughly closed at both ends, a magnetorheological fluid variable damping structure driven by a torsion metamaterial that is roughly closed at both ends (2), a magnetorheological elastomer variable stiffness structure that is roughly cylindrical (3), and a triboelectric nanogenerator vibration sensor structure that is roughly annular (4). The magnetic field generating structure (1) is fitted outside the magnetorheological fluid variable damping structure (2), the magnetorheological elastomer variable stiffness structure (3) is placed inside the magnetorheological fluid variable damping structure (2), and the triboelectric nanogenerator vibration sensor structure (4) is fitted on the magnetorheological fluid variable damping structure (2); the rotation axes of the magnetic field generating structure (1), the magnetorheological fluid variable damping structure (2), the magnetorheological elastomer variable stiffness structure (3) and the triboelectric nanogenerator vibration sensor structure (4) coincide. The magnetic field generating structure (1) is used to generate a magnetic field parallel to the rotation axis, the magnetorheological fluid variable damping structure (2) is used to provide adjustable damping, the magnetorheological elastomer variable stiffness structure (3) is used to provide variable stiffness, and the triboelectric nanogenerator vibration sensor structure (4) is used to sense vibration through self-generated power. The magnetic field generating structure (1) includes an annular lower magnetic housing (101), a cylindrical lower magnetic core (102), a cylindrical copper coil (103), a cylindrical coil hub (104) with grooves on the outer periphery, a cylindrical magnetic housing (105), an upper magnetic core (106) formed by connecting two cylindrical sections that are larger at the top and smaller at the bottom, and an annular upper magnetic housing (107). The copper coil (103) is fitted into the groove on the outer periphery of the coil hub (104), and the magnetic housing (105) is fitted into the outside of the coil hub (104); the upper end of the magnetic housing (105) is detachably fixed to the outer edge of the upper magnetic housing (107), and its lower end is detachably fixed to the outer edge of the lower magnetic housing (101); the upper end of the coil hub (104) abuts against the lower surface of the upper magnetic housing (107), and the lower end of the coil hub (104) abuts against the upper surface of the lower magnetic housing (101); the lower magnetic core (102) is loosely fitted into the coil hub (104), and its lower surface abuts against the lower magnetic housing (101); the upper magnetic core (106) is loosely fitted into the coil hub (104), and its upper part passes through the central hole of the upper magnetic housing (107), and its upper end is flush with the upper surface of the upper magnetic housing (107); The magnetorheological fluid damping structure (2) includes a cylindrical limiting sleeve (201), an upper connecting cover (202), a torsion interlayer (203), a pressure-torsion metamaterial (204), a lower cover (205), a lower connecting piece (206), a planar thrust needle roller bearing (209), and a base (211). The upper periphery of the limiting sleeve (201) is uniformly provided with multiple axial guide grooves; the upper connecting cover (202) is mainly disc-shaped, and the periphery is provided with multiple guide blocks that match the guide grooves of the limiting sleeve (201). The upper connecting cover (202) can move up and down along the axial direction. The lower cover (205) is annular, and the base (211) is roughly cylindrical; the upper surface of the lower cover (205) is fixedly connected to the lower end of the limiting sleeve (201), and the lower surface of the lower cover (205) is fixedly connected to the upper end of the base (211); The lower connector (206) is generally annular in shape, with an outer annular protrusion on the side for placing a planar thrust needle roller bearing (209), which is annular in shape. The twisted interlayer (203) is a cylinder with the lower end fixed and the upper end twisted into a twisted shape. The upper end is fixedly connected to the upper connecting cover (202), and the lower end is fixedly connected to the lower connecting piece (206). The pressure-torsion metamaterial (204) includes multiple circumferentially distributed inclined rods; the upper end of each inclined rod is fixedly connected to the upper connecting cover (202), and the lower end is fixedly connected to the lower connecting piece (206); the projection point of the upper end of the inclined rod on the lower connecting piece (206) is located at the front end of the same circumference of the lower end of the inclined rod in the direction of rotation. The upper surface of the base (211) is provided with an inner ring protrusion in the middle for placing the magnetorheological elastic body variable stiffness structure (3), and the upper surface of the base (211) is provided with an outer ring protrusion at the edge. The lower surface of the base (211) is fixedly connected to the lower magnetic core (102) of the magnetic field generating structure (1). After the lower surface of the lower connector (206) is fixedly connected to the upper surface of the planar thrust needle roller bearing (209), it is fitted between the inner annular protrusion and the outer annular protrusion on the upper surface of the base (211); An inner sealing ring (207) is provided between the inner circumferential surface of the lower connector (206) and the outer circumferential surface of the inner annular protrusion on the upper surface of the base (211), and an outer sealing ring (208) is provided between the outer circumferential surface of the lower connector (206) and the outer annular protrusion on the upper surface of the base (211). The planar thrust needle roller bearing (209) is filled with magnetorheological fluid (210). The triboelectric nanogenerator vibration sensor structure (4) includes multiple contact blocks (401) distributed circumferentially along the lower surface of the upper connecting cover (202) and copper electrodes (402) with lead-out ends. The contact block (401) has one flat end and the other end is hook-shaped; Each contact block (401) has one hook-shaped end that contacts the upper side of a pressure-torsion supermaterial (204) inclined rod, and the other end that contacts the other side of the upper part of the adjacent pressure-torsion supermaterial (204) inclined rod. Its upper surface is fixedly connected to the upper connecting cover (202). The copper electrode (402) is wrapped in a ring around the outside of all contact blocks (401), and its upper edge is fixedly connected to the upper connecting cover (202).

2. The vibration sensing isolator according to claim 1, characterized in that: The upper end of the pressure-twisting supermaterial (204) is fixedly connected to the upper connecting cover (202) with glue, and the lower end of the pressure-twisting supermaterial (204) is fixedly bonded to the lower connecting piece (206) with glue.

3. The vibration sensing isolator according to claim 1, characterized in that: The initial included angle β between the inclined rod of the compression-torsion metamaterial (204) and the lower connector (206) is in the range of 55°. o ~85 o .

4. The vibration sensing isolator according to claim 1, characterized in that: The torsion interlayer (203) is prepared by curing and demolding a magnetorheological elastomer.

5. The vibration sensing isolator according to claim 1, characterized in that: The magnetorheological elastomer variable stiffness structure (3) includes a cylindrical lower magnetic conductor block (301), a cylindrical upper magnetic conductor block (302), and a single-leaf hyperboloid magnetorheological elastomer (303). The bottom of the magnetorheological elastomer (303) is fixedly connected to the upper end of the lower magnetic block (301), and the top of the magnetorheological elastomer (303) is fixedly connected to the lower end of the upper magnetic block (302). The lower magnetic block (301) is fixedly placed in the inner annular protrusion in the middle of the upper surface of the base (211), and the upper end of the upper magnetic block (302) is fixedly connected to the lower surface of the upper connecting cover (202).

6. The vibration-sensing isolator according to claim 5, characterized in that: The bottom of the magnetorheological elastomer (303) is fixedly bonded to the lower magnetic block (301) using silicone rubber, and the top of the magnetorheological elastomer (303) is fixedly bonded to the upper magnetic block (302) using silicone rubber.

7. The vibration sensing isolator according to claim 1, characterized in that: The contact block (401) is integrally molded from Ecoflex material, and the contact area between the pressure-torsion supermaterial (204) and the contact block (401) is coated with nitrile material.

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