Magnetorheological fluid adjustable integrated roller screw active damper

Abstract

The application belongs to the technical field of shock absorbers, and particularly relates to a magneto-rheological fluid adjustable integrated roller screw active shock absorber, which comprises a load platform, the bottom surface of the load platform is fixedly connected with an elastic element, the bottom surface of the elastic element is fixedly connected with a magneto-rheological fluid cavity, the bottom surface of the magneto-rheological fluid cavity is fixedly connected with a double-layer rigid base structure, the inner wall of the magneto-rheological fluid cavity is threadedly connected with a planetary roller screw group, the lower end of the planetary roller screw group is movably arranged in the double-layer rigid base structure, the magneto-rheological fluid cavity is filled with magneto-rheological fluid, the outer wall of the magneto-rheological fluid cavity is provided with an excitation coil, and a negative stiffness elastic element is arranged between the load platform and the double-layer rigid base structure. The application combines the inertial effect, magneto-rheological damping adjustment and positive and negative stiffness parallel vibration isolation principle, converts linear vibration into rotational inertia kinetic energy through the planetary roller screw inertial component, and generates stable inertial effect with large inertia mass ratio.

Description

Technical Field

[0001] This invention belongs to the field of vibration damping technology, specifically relating to a magnetorheological fluid adjustable integrated roller screw active vibration damper. Background Technology

[0002] Vibration and shock control is a key technology for ensuring the normal operation and accuracy of equipment in fields such as precision instruments, aerospace equipment, ship equipment, and precision machining. As modern equipment develops towards higher precision and reliability, the performance requirements for vibration reduction and isolation systems are increasing. Traditional passive vibration isolation devices typically employ a mass-spring-damping system, which is tuned to a specific frequency to suppress the vibration response of the structure. However, traditional linear vibration isolators are limited by their positive stiffness characteristics, resulting in bottlenecks in low-frequency vibration isolation: to obtain a lower natural frequency, the spring stiffness needs to be reduced or the mass of the mass block increased, but excessively low stiffness sacrifices the static load-bearing capacity of the system, while excessive mass increases the size and weight of the device, making it difficult to meet the requirements of lightweight and compact design in practical engineering.

[0003] Furthermore, existing vibration isolation devices typically suffer from the following three shortcomings: First, most vibration isolators are designed only for a single direction (vertical or horizontal), making it difficult to cope with multi-directional coupled vibrations; second, their damping characteristics are usually fixed or passive, unable to be adjusted in real time according to changes in vibration amplitude and frequency, resulting in poor adaptability to complex vibration conditions with wide frequency bands and varying amplitudes; third, when encountering sudden large-amplitude impact loads, traditional vibration isolation devices are prone to failure problems such as wedging and jamming of the threaded drive pair and hard impact of internal parts, lacking the ability to autonomously switch between normal operating conditions and impact protection states. In the field of inertial vibration isolation, ball screw-type inertial containers have been extensively studied, but their inertia-to-mass ratio is limited by the radial dimension of the flywheel, making it difficult to obtain a sufficiently large inertial effect in a compact space. Therefore, there is an urgent need for a new integrated vibration isolation device that combines multi-directional vibration isolation, adjustable damping, large inertial capacity effect, and impact protection functions. Summary of the Invention

[0004] The purpose of this invention is to provide a magnetorheological fluid-adjustable integrated roller screw active vibration damper to solve the aforementioned problems. This device comprehensively utilizes the inertial capacitance effect, magnetorheological damping adjustment, and the principle of parallel positive and negative stiffness vibration isolation. Through the planetary roller screw inertial capacitance assembly, linear vibration is converted into rotational inertial kinetic energy, generating a stable inertial capacitance effect with a large inertia-to-mass ratio. Simultaneously, a metal-rubber matrix and a negative stiffness spring are introduced to form a parallel elastic structure of positive and negative stiffness, effectively reducing the system's equivalent stiffness and achieving efficient vibration isolation at low and even ultra-low frequencies. Furthermore, through the design of the disc spring assembly, it does not participate in system operation under normal vibration conditions but automatically triggers flexible buffer limiting under extreme impact conditions, achieving autonomous impact protection. It is suitable for engineering fields sensitive to vibration and impact, such as precision instruments, aerospace equipment, ship equipment, and precision machining.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] A magnetorheological fluid adjustable integrated roller screw active vibration damper includes a load platform, an elastic element fixedly connected to the bottom surface of the load platform, a magnetorheological fluid cavity fixedly connected to the bottom surface of the elastic element, a double-layer rigid base structure fixedly connected to the bottom surface of the magnetorheological fluid cavity, a planetary roller screw assembly threadedly fitted to the inner wall of the magnetorheological fluid cavity, the lower end of the planetary roller screw assembly movably passing through the double-layer rigid base structure, the magnetorheological fluid cavity being filled with magnetorheological fluid, an excitation coil wound around the outer wall of the magnetorheological fluid cavity, and a negative stiffness elastic element installed between the load platform and the double-layer rigid base structure.

[0007] Preferably, the elastic element is a metal-rubber matrix, which is fixedly connected between the load platform and the magnetorheological fluid cavity.

[0008] Preferably, the planetary roller screw assembly includes a central screw, the lower end of which is movably inserted into the double-layer rigid base structure, and a planetary roller screw inertia-capacity assembly is rotatably provided on the upper outer side of the central screw, with the outer wall of the central screw threadedly engaged with the planetary roller screw inertia-capacity assembly.

[0009] The planetary roller screw inertia-capacity assembly includes at least three planetary rollers. Several planetary rollers are equally spaced along the axis of the central screw. The planetary rollers are threadedly engaged with the outer wall of the central screw. A flywheel is fitted around the outer side of the planetary rollers. The outer wall of the flywheel is threadedly engaged with the inner wall of the magnetorheological fluid cavity. The central screw is coaxially arranged with the magnetorheological fluid cavity. A gap is reserved between the circumcircle formed by the planetary rollers and the inner wall of the flywheel. The flywheel is filled with magnetorheological fluid. The top of the central screw is fixedly connected to the load platform. The top and bottom sidewalls of the flywheel have openings for the magnetorheological fluid to pass through.

[0010] Preferably, there are nine planetary rollers, with an upper shaft end baffle rotatably connected to the upper end of each planetary roller and a lower shaft end baffle rotatably connected to the lower end of each planetary roller. The upper and lower shaft end baffles are located outside the magnetorheological fluid cavity and are fixedly connected to the magnetorheological fluid cavity.

[0011] Preferably, the outer wall of the flywheel and the outer wall of the central screw have the same thread direction.

[0012] Preferably, the double-layer rigid base structure includes an upper mounting base and a lower foundation base fixedly connected to the bottom surface of the upper mounting base, with the lower end of the central lead screw movably passing through the upper mounting base and the lower foundation base.

[0013] Preferably, the upper mounting base is a hollow structure, and a disc spring assembly is provided inside the upper mounting base. The central lead screw passes through the center of the disc spring assembly, and a gap is reserved between the disc spring assembly and the central lead screw. A shoulder is provided on the lower outer wall of the central lead screw. The shoulder is located above the disc spring assembly and a gap is reserved between the shoulder and the disc spring assembly. The outer diameter of the shoulder is smaller than the through hole opened on the top surface of the upper mounting base.

[0014] Preferably, the negative stiffness elastic element is a negative stiffness spring, and at least three negative stiffness springs are provided, with a plurality of negative stiffness springs arranged at equal intervals along the magnetorheological fluid cavity.

[0015] The present invention has the following technical effects:

[0016] (1) This invention organically integrates a planetary roller screw assembly, a magnetorheological adjustable damping structure, and a parallel elastic support structure with positive and negative stiffness, thereby overcoming the fundamental limitations of traditional vibration isolation devices in terms of vibration isolation dimension, frequency bandwidth, damping adaptability, and impact protection at the system level. Regarding the inertial capacitance effect, the dual motion of the planetary rollers' rotation and revolution drives the flywheel, significantly improving the inertia-to-mass ratio and output force compared to traditional ball screw-type inertial containers. In terms of stiffness characteristics, the parallel principle of positive and negative stiffness allows the system's equivalent dynamic stiffness to be continuously adjusted to near zero, achieving an ideal stiffness match of high static and low dynamic stiffness—the static bearing capacity is not weakened by the introduction of negative stiffness, while the dynamic stiffness can be reduced to near zero. Regarding operational adaptability, the separate design of normal vibration isolation and ultimate protection balances daily vibration isolation performance and structural safety under extreme conditions. These technological breakthroughs make this invention significantly superior to existing technologies in terms of structural form, performance indicators, and operational adaptability.

[0017] (2) Stable and efficient inertial capacity effect: The double-layer rigid base structure ensures that the magnetorheological fluid cavity is absolutely stationary. The meshing constraint between the fixed thread on the inner wall of the magnetorheological fluid cavity and the external thread of the flywheel is used to realize the stable transmission from the translation of the screw to the rotation of the flywheel, completely avoiding the problem of inertial capacity decay or failure caused by cavity floating. The planetary roller drives the flywheel with both rotation and revolution. When the radial dimension of the flywheel is the same, the inertial mass ratio and output force can be significantly improved, so that the device can output stable and continuous virtual inertial mass under all normal working conditions.

[0018] (3) Excellent low-frequency vibration isolation performance: The positive stiffness provided by the metal rubber matrix and the negative stiffness provided by the six tensile negative stiffness springs are coupled in parallel, which greatly reduces the equivalent dynamic stiffness of the system, effectively reduces the natural frequency of the structure, significantly improves the vibration isolation effect of low-frequency and ultra-low-frequency vibrations, and solves the defects of traditional vibration isolation devices such as poor low-frequency vibration isolation capability and easy resonance.

[0019] (4) Damping is continuously adjustable and has strong adaptability to working conditions: Relying on the rheological controllable characteristics of magnetorheological fluid, the damping force of the system can be continuously changed by adjusting the excitation current. It can be adjusted in real time according to the vibration amplitude and vibration frequency, taking into account both small vibration energy consumption and large vibration suppression, and has excellent vibration isolation adaptive performance.

[0020] (5) Outstanding autonomous protection capability against extreme impacts: The disc spring assembly adopts the design of "no intervention under normal conditions and only working when the limit is exceeded". Without the need for external sensors or active controllers, it can automatically trigger flexible buffer protection under extreme impact conditions, effectively avoiding the wedge jamming of the threaded transmission pair, hard impact of the internal structure and damage to parts, and greatly improving the impact resistance and operational reliability of the device.

[0021] (6) High structural integration and good operational stability: The whole structure is arranged in a coaxial symmetrical manner, and the rigid support structure of the double-layer base has sufficient rigidity; the planetary roller screw assembly, magnetorheological damping assembly, positive and negative stiffness elastic support assembly and disc spring impact limit assembly are clearly zoned and their functions do not interfere with each other. The normal vibration isolation system and the ultimate protection system work in layers, taking into account both daily vibration isolation performance and structural safety under extreme working conditions, and are highly practical for engineering.

[0022] (7) Wide range of adjustable parameters and strong adaptability: The number and diameter of planetary rollers can be flexibly adjusted according to the target inertia-mass ratio. When the radial dimension of the flywheel is limited, the inertia coefficient and inertia ratio of the device can be increased by increasing the number of planetary rollers or changing the radius of the planetary rollers; the magnitude of the damping force can be continuously changed by adjusting the excitation current; the negative stiffness characteristics can be changed by adjusting the preload of the tensile negative stiffness spring; the impact buffer stroke and stiffness can be adjusted by changing the stacking method and number of disc springs. The parameters of each functional module are independently adjustable to adapt to complex and ever-changing working conditions. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure of AA

[0026] Figure 3 This is a structural diagram of the planetary roller screw inertia-compression assembly;

[0027] Figure 4 for Figure 3 Schematic diagram of the cross-sectional structure of BB

[0028] Figure 5 A schematic diagram showing the planetary rollers arranged in a circumferential array along the central lead screw;

[0029] Figure 6 This is a schematic diagram of a disc spring assembly;

[0030] Figure 7 This is a schematic diagram of the present invention;

[0031] Figure 8 This is a comparison of the transmissivity curves of the vibration damper of the present invention and the traditional linear vibration isolator.

[0032] The components include: 1. Load platform; 2. Metal-rubber substrate; 3. Negative stiffness spring; 4. Magnetorheological fluid cavity; 5. Excitation coil; 6. Planetary roller screw inertia-capacitance assembly; 6-1. Planetary roller; 6-2. Upper shaft end baffle; 6-3. Lower shaft end baffle; 6-4. Flywheel; 6-5. Annular clearance; 7. Center screw; 701. Shoulder; 8. Upper mounting base; 9. Lower foundation base; 10. Disc spring assembly. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Reference Figures 1 to 7 As shown, this embodiment provides a magnetorheological fluid adjustable integrated roller screw active vibration damper, including a load platform 1, an elastic element fixedly connected to the bottom surface of the load platform 1, a magnetorheological fluid cavity 4 fixedly connected to the bottom surface of the elastic element, a double-layer rigid base structure fixedly connected to the bottom surface of the magnetorheological fluid cavity 4, a planetary roller screw assembly threadedly fitted to the inner wall of the magnetorheological fluid cavity 4, the lower end of the planetary roller screw assembly movably passing through the double-layer rigid base structure, the magnetorheological fluid cavity 4 being filled with magnetorheological fluid, an excitation coil 5 wound around the outer wall of the magnetorheological fluid cavity 4, and a negative stiffness elastic element installed between the load platform 1 and the double-layer rigid base structure.

[0036] The scheme was further optimized so that the elastic element is a metal-rubber substrate 2, which is fixedly connected between the load platform 1 and the magnetorheological fluid cavity 4.

[0037] The scheme is further optimized. The planetary roller screw assembly includes a central screw 7. The lower end of the central screw 7 is movably inserted into the double-layer rigid base structure. The planetary roller screw inertia assembly 6 is rotatably provided on the upper outer side of the central screw 7. The outer wall of the central screw 7 is threadedly engaged with the planetary roller screw inertia assembly 6.

[0038] The planetary roller screw inertia-capacitance assembly 6 includes at least three planetary rollers 6-1. Several planetary rollers 6-1 are evenly spaced along the axis of the central screw 7. The planetary rollers 6-1 are threadedly engaged with the outer wall of the central screw 7. A flywheel 6-4 is sleeved on the outer side of the several planetary rollers 6-1. The outer wall of the flywheel 6-4 is threadedly engaged with the inner wall of the magnetorheological fluid cavity 4. The central screw 7 is coaxially arranged with the magnetorheological fluid cavity 4. A gap is reserved between the circumcircle formed by the several planetary rollers 6-1 and the inner wall of the flywheel 6-4. The flywheel 6-4 is filled with magnetorheological fluid. The top of the central screw 7 is fixedly connected to the load platform 1. The top and bottom sidewalls of the flywheel 6-4 have openings for the magnetorheological fluid to pass through.

[0039] In a further optimized design, the number of planetary rollers 6-1 is nine. The upper end of the planetary rollers 6-1 is rotatably connected to the upper shaft end baffle 6-2, and the lower end of the planetary rollers 6-1 is rotatably connected to the lower shaft end baffle 6-3. The upper shaft end baffle 6-2 and the lower shaft end baffle 6-3 are located outside the magnetorheological fluid cavity 4 and are fixedly connected to the magnetorheological fluid cavity 4.

[0040] The design was further optimized so that the threads on the outer walls of flywheel 6-4 and the outer walls of the center screw 7 have the same direction of rotation.

[0041] The scheme is further optimized. The double-layer rigid base structure includes an upper mounting base 8 and a lower foundation base 9 which is fixedly connected to the bottom surface of the upper mounting base 8. The lower end of the central screw 7 is movably inserted into the upper mounting base 8 and the lower foundation base 9.

[0042] Further optimization of the design: the upper mounting base 8 has a hollow structure, and a disc spring assembly 10 is provided inside the upper mounting base 8. The central lead screw 7 passes through the center of the disc spring assembly 10, and a gap is reserved between the disc spring assembly 10 and the central lead screw 7. The lower outer wall of the central lead screw 7 is provided with a shoulder 701, which is located above the disc spring assembly 10 and is reserved with a gap between it and the disc spring assembly 10. The outer diameter of the shoulder 701 is smaller than the through hole opened on the top surface of the upper mounting base 8.

[0043] The scheme is further optimized so that the negative stiffness elastic element is a negative stiffness spring 3, and at least three negative stiffness springs 3 are set up, with several negative stiffness springs 3 arranged at equal intervals along the magnetorheological fluid cavity 4.

[0044] The load platform 1 is located at the top of the device and serves as the input end for vibration and impact loads of the entire machine. The double-layer rigid base assembly includes an upper mounting base 8 and a lower foundation base 9. The two bases have no relative displacement and together form a static rigid base, providing a stable mounting foundation for the entire device. The bottom of the magnetorheological fluid cavity 4 is rigidly fixed to the upper surface of the upper mounting base 8. After assembly, it remains absolutely stationary throughout the entire process, providing a fixed threaded constraint reference for the internal inertial-capacitive transmission mechanism.

[0045] The planetary roller 6-1 is made of bearing steel GCr15. The threaded parts of the center screw 7 and planetary roller 6-1 are quenched or coated with Teflon to increase wear resistance and reduce the coefficient of friction.

[0046] The central lead screw 7 is vertically arranged on the central axis of the device. The top of the lead screw is rigidly fixed to the load platform 1. The central lead screw can move vertically back and forth with the load platform and does not rotate on its own during operation. The central lead screw 7 passes downward through the magnetorheological fluid cavity 4 and is assembled with the lower foundation base 9.

[0047] The excitation coil 5 is embedded in the annular groove on the outer wall of the magnetorheological fluid cavity 4. The coil is connected to a controllable DC power supply. By adjusting the magnitude of the excitation current, the shear yield strength of the magnetorheological fluid within the cavity can be changed, achieving continuous adjustment of the damping force. The magnetorheological fluid cavity 4 and the flywheel 6-4 are made of electrically pure iron or low-carbon steel with good magnetic permeability to ensure effective closure of the magnetic circuit.

[0048] A ring-shaped metal-rubber substrate 2 is coaxially arranged between the load platform 1 and the upper surface of the magnetorheological fluid cavity 4. The metal-rubber substrate 2 is made of stainless steel wire through a spiral winding and cold-pressing process, possessing excellent elasticity and damping characteristics, providing positive stiffness support and basic damping energy dissipation for the system. Six tension negative stiffness springs 3 are evenly arranged circumferentially around the device, with the upper end of the springs hinged to the load platform 1 and the lower end hinged to the lower foundation base 9. The tension negative stiffness springs 3 and the metal-rubber substrate 2 cooperate to form a parallel elastic structure of positive and negative stiffness. At the static equilibrium position, the rubber substrate provides static support to the load. When the load platform 1 moves away from the equilibrium position, the metal-rubber substrate 2 undergoes elastic deformation, providing a position restoring force and generating a positive stiffness effect; the springs, being tension springs, exert an elastic pulling force on the load platform that deviates from the equilibrium position, generating a negative stiffness effect. The negative stiffness coupling cancels out the system's redundant stiffness, significantly reducing the system's equivalent stiffness and shifting the natural frequency significantly to lower frequencies, achieving excellent low-frequency vibration isolation characteristics.

[0049] The disc spring assembly 10 is a stacked safety buffer component, consisting of multiple disc springs stacked in the same direction or in opposite directions, possessing high stiffness, short stroke, and high energy absorption characteristics. The disc spring assembly 10 is coaxially arranged around the lower surface of the upper mounting base 8, and is integrally fitted onto the outer region of the bottom end of the central lead screw 7. There is a gap between the lead screw and the disc springs, and the upper end of the lead screw is fixedly connected to the load platform. The disc spring assembly 10 is made of 60Si2MnA springs.

[0050] The motion coordination relationships and working process of this device strictly distinguish between normal small-amplitude vibration conditions and extreme large-impact conditions. The motion coordination relationships of each component are clear, without interference or conflict of principle, as detailed below:

[0051] The planetary roller screw assembly motion process: When the load platform 1 is excited by vibration, causing the central screw 7 to produce vertical reciprocating translational motion, since the inner wall thread of the outer magnetorheological fluid cavity 4 is completely fixed and does not produce any displacement, the linear displacement of the central screw 7 is forcibly converted into the rotation and revolution motion of the planetary rollers 6-1 through multi-start thread engagement, thereby driving the integrated flywheel assembly to rotate around the central axis. The outer external thread of the flywheel 6-4 helically rolls along the inner thread of the cavity 4. Through the reversible transmission conversion of "screw translational motion - roller planetary motion - flywheel rotation", the linear vibration energy is converted into the rotational inertial kinetic energy of the flywheel, stably generating the inertial capacitance effect. The cavity is stationary, and the flywheel helically rolls relative to the cavity, with precise motion coordination and no risk of locking.

[0052] Damping adjustment process: The flywheel 6-4 continuously rotates and oscillates with the vibration. By changing the excitation current of coil 5, the viscosity and shear resistance of the magnetorheological fluid can be adjusted, achieving real-time adjustable damping to meet the suppression requirements of different vibration intensities.

[0053] Elastic support process: During the reciprocating motion of the load platform 1, the continuous elastic deformation of the metal rubber matrix 2 provides positive stiffness and energy dissipation of the foundation. The tensile negative stiffness spring 3 dynamically generates negative stiffness with the vertical displacement of the platform. The coupling of positive and negative stiffness cancels out the redundant stiffness of the system, giving the system the mechanical characteristics of low natural frequency and high vibration isolation range.

[0054] Impact process of disc springs: Under normal small-amplitude vibration conditions, the vertical displacement of the central screw 7 is small, and the disc spring assembly 10 is in a free preload state, without compression deformation, and does not participate in the system stiffness output, thus not interfering with the low-frequency vibration isolation and inertial capacitance working characteristics of the whole machine. Only when the device encounters a sudden large-amplitude impact load and the downward displacement of the central screw 7 exceeds the set limit stroke, it contacts and squeezes the disc spring assembly 10, causing the disc spring to undergo instantaneous elastic compression, absorbing the peak impact energy, completing flexible limit buffering, and effectively avoiding the wedging and jamming of the threaded transmission pair, hard impact on the internal structure, and damage to parts.

[0055] The load platform 1 and the mass it bears are M, and the metal-rubber matrix 2 provides the positive stiffness k. p(>0), the six tension springs 3 generate negative stiffness k during vertical deformation. n (<0), the equivalent total stiffness k of the system near the static equilibrium position eq =k p +k n The rotation of flywheel 6-4 generates a capacitive inertial effect, and its output force is proportional to the relative acceleration at both ends. The magnetorheological fluid in the annular gap 6-5 between the flywheel and the planetary rollers provides adjustable damping c under shearing action. By reasonably designing the preload of the tension negative stiffness spring 3, k can be adjusted. eq The frequency approaches zero near the static equilibrium position, thereby significantly reducing the system's natural frequency. At the same time, the inertial capacitance effect further extends the effective vibration isolation frequency band to lower frequencies, achieving efficient vibration isolation at low and even ultra-low frequencies.

[0056] Compared to traditional linear vibration isolators, the magnetorheological fluid-adjustable integrated roller screw active vibration damper proposed in this invention significantly reduces the peak value in the resonance region and shifts the natural frequency significantly to lower frequencies, exhibiting superior vibration damping performance across the entire frequency range. Particularly in the low-frequency range, the parallel connection of positive and negative stiffnesses leads to a substantial reduction in the system's equivalent dynamic stiffness, and the synergistic effect of the inertial effect provided by the planetary roller screw inertial capacitance assembly results in a significantly better low-frequency vibration isolation performance than traditional linear vibration isolators. Furthermore, by adjusting the excitation current to change the magnetorheological fluid damping, the vibration isolation performance of the system in different frequency ranges can be further optimized; by changing the number and diameter of the planetary rollers, the inertia-mass coefficient and inertia-mass ratio of the device can be adjusted when the radial dimension of the flywheel is limited, to adapt to different vibration input conditions.

[0057] In this specific embodiment, there is no relative displacement between the upper mounting base 8 and the lower foundation base 9, providing an absolutely static fixed constraint reference for the magnetorheological fluid cavity 4. The outer shell (magnetorheological fluid cavity 4 and base assembly) adopts a closed or semi-closed structure, which protects the internal planetary roller screw inertia capacity assembly 6 and prevents external debris from entering and affecting the movement of the mechanism.

[0058] The working process of this invention is as follows: When external vibration is transmitted to the device, the load platform 1 undergoes vertical reciprocating motion relative to the stationary base under inertia. The central lead screw 7 vibrates synchronously with the load platform 1, and its linear displacement drives the nine sets of planetary rollers 6-1 to generate rotation and revolution through multi-start thread meshing, thereby driving the flywheel 6-4 to rotate, converting the linear vibration energy into rotational inertial kinetic energy and generating an inertial capacitance effect. At the same time, the magnetorheological fluid in the annular gap 6-5 between the flywheel 6-4 and the planetary rollers 6-1 provides damping force under shear action, and the magnitude of the damping force can be changed by adjusting the current of the excitation coil 5. The metal rubber matrix 2 provides positive stiffness support through continuous elastic deformation during the movement of the load platform 1, and the six tensile negative stiffness springs 3 dynamically generate a negative stiffness effect with the vertical displacement of the platform. The parallel connection of positive and negative stiffness significantly reduces the equivalent stiffness of the system. When encountering a sudden large-amplitude impact, the disc spring group 10 is contacted and compressed, and the disc springs instantly absorb the impact energy to complete the flexible buffering and limiting, and automatically reset after the impact ends. The damping force can be continuously adjusted by rotating the current adjustment knob of the excitation coil 5. The inertia coefficient can be adjusted by replacing the planetary rollers 6-1 of different specifications or changing their number. The negative stiffness characteristics can be changed by adjusting the initial preload of the tensile negative stiffness spring 3 or by replacing the spring with one of different stiffness, so as to adapt to external excitation of different frequencies.

[0059] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0060] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A magnetorheological fluid adjustable integrated roller screw active vibration damper, characterized in that, The system includes a load platform (1), an elastic element fixedly connected to the bottom surface of the load platform (1), a magnetorheological fluid cavity (4) fixedly connected to the bottom surface of the elastic element, a double-layer rigid base structure fixedly connected to the bottom surface of the magnetorheological fluid cavity (4), a planetary roller screw assembly threadedly fitted to the inner wall of the magnetorheological fluid cavity (4), the lower end of the planetary roller screw assembly movably passing through the double-layer rigid base structure, the magnetorheological fluid cavity (4) being filled with magnetorheological fluid, an excitation coil (5) wound around the outer wall of the magnetorheological fluid cavity (4), and a negative stiffness elastic element installed between the load platform (1) and the double-layer rigid base structure.

2. The magnetorheological fluid adjustable integrated roller screw active vibration damper according to claim 1, characterized in that, The elastic element is a metal-rubber matrix (2), which is fixedly connected between the load platform (1) and the magnetorheological fluid cavity (4).

3. The magnetorheological fluid adjustable integrated roller screw active vibration damper according to claim 1, characterized in that, The planetary roller screw assembly includes a central screw (7), the lower end of which is movably inserted into the double-layer rigid base structure. The upper outer side of the central screw (7) is rotatably provided with a planetary roller screw inertia assembly (6), and the outer wall of the central screw (7) is threadedly engaged with the planetary roller screw inertia assembly (6). The planetary roller screw inertia-capacity assembly (6) includes at least three planetary rollers (6-1). Several planetary rollers (6-1) are arranged at equal intervals along the axis of the central screw (7). The planetary rollers (6-1) are threadedly engaged with the outer wall of the central screw (7). A flywheel (6-4) is sleeved on the outer side of several planetary rollers (6-1). The outer wall of the flywheel (6-4) is threadedly engaged with the inner wall of the magnetorheological fluid cavity (4). The central screw (7) is coaxially arranged with the magnetorheological fluid cavity (4). A gap is reserved between the circumscribed circle formed by several planetary rollers (6-1) and the inner wall of the flywheel (6-4). The flywheel (6-4) is filled with magnetorheological fluid. The top end of the central screw (7) is fixedly connected to the load platform (1). The top and bottom sidewalls of the flywheel (6-4) have openings for the magnetorheological fluid to pass through.

4. The magnetorheological fluid adjustable integrated roller screw active vibration damper according to claim 3, characterized in that, There are nine planetary rollers (6-1). The upper end of each planetary roller (6-1) is rotatably connected to an upper shaft end baffle (6-2), and the lower end of each planetary roller (6-1) is rotatably connected to a lower shaft end baffle (6-3). The upper shaft end baffle (6-2) and the lower shaft end baffle (6-3) are located outside the magnetorheological fluid cavity (4) and are fixedly connected to the magnetorheological fluid cavity (4).

5. The magnetorheological fluid adjustable integrated roller screw active vibration damper according to claim 3, characterized in that, The outer wall of the flywheel (6-4) and the outer wall of the center screw (7) have the same thread direction.

6. The magnetorheological fluid adjustable integrated roller screw active vibration damper according to claim 3, characterized in that, The double-layer rigid base structure includes an upper mounting base (8) and a lower foundation base (9) fixedly connected to the bottom surface of the upper mounting base (8). The lower end of the central screw (7) is movably inserted into the upper mounting base (8) and the lower foundation base (9).

7. The magnetorheological fluid adjustable integrated roller screw active vibration damper according to claim 6, characterized in that, The upper mounting base (8) is a hollow structure. Inside the upper mounting base (8) is a disc spring assembly (10). The central lead screw (7) passes through the center of the disc spring assembly (10). A gap is reserved between the disc spring assembly (10) and the central lead screw (7). The lower outer wall of the central lead screw (7) is provided with a shoulder (701). The shoulder (701) is located above the disc spring assembly (10) and is reserved with a gap between it and the disc spring assembly (10). The outer diameter of the shoulder (701) is smaller than the through hole opened on the top surface of the upper mounting base (8).

8. The magnetorheological fluid adjustable integrated roller screw active vibration damper according to claim 1, characterized in that, The negative stiffness elastic element is a negative stiffness spring (3), and at least three negative stiffness springs (3) are provided. Several negative stiffness springs (3) are arranged at equal intervals along the magnetorheological fluid cavity (4).

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