A multi-stage tuned vibration reduction system of inertance-negative stiffness based on butterfly viscous damping

Abstract

The present invention relates to an inertia - negative stiffness multi - tuned vibration reduction system based on butterfly viscous damping. The system includes symmetrically arranged unidirectional rotating inertia - viscous damping subsystems and transmission gears; a ball screw mechanism is provided inside a fixed outer cylinder and extends out of the fixed outer cylinder. One end of a rotating inner cylinder is connected to the ball screw mechanism through a unidirectional bearing; the extending end of the ball screw mechanism meshes with the transmission gear, the transmission gear meshes with a driving tooth shaft, and the driving tooth shaft is connected to the structure through a spring. Compared with the prior art, the present invention can achieve butterfly damping that only generates energy - dissipation effects in the second and fourth quadrants, avoid excessive damping control forces in the first and third quadrants, and significantly improve the control effect of the peak value of the structural acceleration response; at the same time, it can achieve an equivalent negative stiffness, which can reduce the overall stiffness of the structure to amplify the deformation of the damping unit and generate a stronger energy - dissipation effect; it can also perform multi - tuned on the structure and provide a damping deformation amplification space, which is beneficial to broadening the vibration control frequency band.

Description

Technical Field

[0001] The present invention belongs to the technical field of civil engineering and relates to an inerter-negative stiffness multi-stage tuned vibration damping system based on butterfly viscous damping. Background Art

[0002] Among products and technologies with negative stiffness effects, most need to use springs or magnets to achieve the negative stiffness behavior of the device. These products themselves can only provide negative stiffness for the vibration control of the structure, cannot provide damping for the structure, or can only provide a small amount of damping, and it is difficult to help the structure dissipate vibration energy. The negative stiffness implementation mechanism with both negative stiffness effect and energy dissipation effect remains to be further explored.

[0003] Among products and technologies with inerter behavior, although the inerter also has dynamic negative stiffness effect and tuning function, the negative stiffness generated by it is highly dependent on the external excitation frequency, and the negative stiffness effect is unstable; moreover, the inerter behavior itself does not provide damping, and it is difficult to help the structure dissipate vibration energy. In addition, how to use the tuning function of the inerter to broaden the vibration control frequency band of the system, and use the dynamic negative stiffness that can be generated by it to achieve negative stiffness enhancement, and form a control system in which the inerter-damping-negative stiffness work together remains to be further explored.

[0004] Patent CN109577727A discloses a particle damper using an inerter, which includes a fixing plate fixed on the ground, an inerter unit and a particle damping unit slidably placed on the bottom surface. The inerter unit and the particle damping unit are connected by a connecting spring, and the fixing plate is connected to the inerter unit through a gear set and drives the inerter unit to move. However, the device described in this patent only has an inerter unit, a particle mass unit and a non-linear energy dissipation element based on particle collision. Therefore, the technical solution weakens the inertial energy absorption effect while realizing collision energy dissipation, and cannot provide the damping force related to the acceleration phase required for the control of the structural acceleration response, and it is difficult to achieve the targeted dissipation of vibration energy in the second and fourth quadrants; in addition, this device does not have a negative stiffness effect, and only has a two-stage tuning mechanism in terms of tuning, that is, the inerter unit and the particle mass unit, and the tuning range of the overall frequency of the structure is limited.

[0005] Patent CN117569473A discloses an inertial mass damper of a lead screw flywheel mechanism, which includes a first ball screw inerter structure; a second ball screw inerter structure, and the second ball screw inerter structure is installed on the first ball screw inerter structure; a front-end structure, and the front-end structure is installed on one side of the first ball screw inerter structure. However, the device described in this patent is an inerter unit, does not have the ability to dissipate energy, and it is difficult to achieve the dissipation of vibration energy; it only has a one-stage tuning mechanism, does not have an equivalent negative stiffness effect and the damping control force related to the acceleration phase for structural acceleration control, and the tuning range of the overall frequency of the structure is limited. Summary of the Invention

[0006] The object of the present invention is to overcome at least one defect of the above-mentioned existing technologies and provide an inertia - negative stiffness multi - tuned vibration reduction system based on butterfly viscous damping. The present invention can achieve butterfly damping that only generates energy - dissipation effects in the second and fourth quadrants, avoid excessive damping control forces in the first and third quadrants, and significantly improve the control effect of the peak value of the structural acceleration response; at the same time, it can achieve an equivalent negative stiffness, which can reduce the overall stiffness of the structure to amplify the deformation of the damping unit and generate a stronger energy - dissipation effect; it can also multi - tune the structure and provide a damping deformation amplification space, which is beneficial to broadening the vibration control frequency band.

[0007] The object of the present invention can be achieved by the following technical solutions:

[0008] One of the technical solutions of the present invention is to provide an inertia - negative stiffness multi - tuned vibration reduction system based on butterfly viscous damping. The system includes symmetrically arranged unidirectional rotary inertia - viscous damping subsystems, transmission gears, as well as a fixed seat, a driving tooth shaft, and a spring. One side of the fixed seat is fixedly connected to the structure, and the other side is fixedly connected to a fixed outer cylinder; the fixed seat is used to fix the relative positions of the components in the whole system.

[0009] The unidirectional rotary inertia - viscous damping subsystem includes a fixed outer cylinder. A ball screw mechanism is arranged inside the fixed outer cylinder and extends out of the fixed outer cylinder. The rotary inner cylinder is arranged inside the fixed outer cylinder and on one side of the ball screw mechanism. One end of the rotary inner cylinder is connected to the ball screw mechanism through a unidirectional bearing. The space between the rotary inner cylinder and the side wall of the fixed outer cylinder is filled with viscous fluid.

[0010] The extending end of the ball screw mechanism meshes with the transmission gear, the transmission gear meshes with the driving tooth shaft, and the driving tooth shaft is connected to the structure through a spring.

[0011] As a preferred technical solution, the lower part of the fixed seat is fixedly connected to the structure bottom plate, and the upper part is fixedly connected to the fixed outer cylinder. The driving tooth shaft is connected to the structure top plate.

[0012] As a preferred technical solution, the upper part of the fixed seat is provided with a groove body, and the fixed seat is clamped with the fixed outer cylinder through the groove body.

[0013] As a preferred technical solution, the rotary inner cylinder is arranged inside the fixed outer cylinder and on the inner side of the ball screw mechanism. The outer end of the rotary inner cylinder is connected to the ball screw mechanism through a unidirectional bearing.

[0014] Furthermore, the ball screw mechanism includes a nut, a screw rod, and balls. The screw rod extends into the nut and the rotary inner cylinder, and the space between the screw rod and the side wall of the nut is filled with balls.

[0015] Furthermore, a structural plate is arranged inside the fixed outer cylinder, the lead screw extends outside the structural plate, and one end of the nut is fixedly connected to the structural plate, and the two move together; the structural plate is connected to the fixed outer cylinder through a thrust bearing, and the thrust bearing can limit the translational movement between the structural plate and the fixed outer cylinder, but does not limit the rotational movement.

[0016] As a preferred technical solution, the outer end of the nut is fixedly connected to the structural plate through a connecting bolt.

[0017] As a preferred technical solution, both ends of the structural plate are connected to the fixed outer cylinder through two thrust bearings.

[0018] Furthermore, one end of the rotating inner cylinder is connected to the nut through a one-way bearing, and the other end is connected to the fixed outer cylinder through a thrust bearing; the forward rotation of the nut can be transmitted to the rotating inner cylinder through the one-way bearing, and the reverse rotation cannot.

[0019] As a preferred technical solution, the outer end of the rotating inner cylinder is connected to the nut through a one-way bearing, and the inner end is connected to the fixed outer cylinder through a thrust bearing.

[0020] Furthermore, teeth are arranged on the surface of one end of the driving gear shaft, the tooth pitch is smaller than the center distance of the symmetrically arranged transmission gears, teeth are arranged on the surface of the extending end of the lead screw, one side of the transmission gear meshes with one end of the driving gear shaft, and the other side meshes with the extending end of the lead screw.

[0021] As a preferred technical solution, the upper part of the transmission gear meshes with one end of the driving gear shaft, and the lower part meshes with the extending end of the lead screw.

[0022] Furthermore, the other end of the driving gear shaft extends into the driving shaft to keep the movements of the driving gear shaft and the driving shaft on the same straight line. A groove is provided at one end of the driving shaft for the other end of the driving gear shaft to move inside the driving shaft; the driving shaft is used to drive the entire system to work;

[0023] The driving gear shaft is connected to the driving shaft through a spring, and one end of the driving shaft is connected to the structure; the horizontal force acting on the driving shaft is transmitted to the driving gear shaft through the spring; the driving shaft and the driving gear shaft are connected through a spring, which can amplify the horizontal displacement of the driving gear shaft, that is, the horizontal displacement of the driving gear shaft is greater than the horizontal displacement of the driving shaft.

[0024] As a preferred technical solution, an erbium ring is provided at one end of the driving shaft, and the erbium ring is connected to the structural top plate.

[0025] Further, the spring is a single ordinary spring. When the ordinary spring is in a plastic state under tension, stiffness softening occurs, resulting in a nonlinear effect. The spring is sleeved on the driving gear shaft, and a protrusion is provided on the driving gear shaft. One end of the spring is fixed to the protrusion of the driving gear shaft, and the other end is fixed to one end of the driving shaft.

[0026] Further, the spring is composed of multiple ordinary springs to form a spring group. The vertical components of the forces exerted by the ordinary springs in the spring group cancel each other out, and the horizontal components are superimposed on each other. Moreover, the horizontal stiffness varies nonlinearly with displacement. The spring group as a whole exhibits a nonlinear effect. The springs are vertically symmetrically arranged on both sides of the driving gear shaft. One end of the spring is fixed to the driving gear shaft, and the other end is fixed to the inner side of the groove body of the driving shaft.

[0027] The symmetrically arranged single-direction rotary inertance-viscous damping subsystem can generate butterfly viscous damping and third-order inertance behavior located in the second and fourth quadrants of the force-displacement plane under the drive of the driving gear shaft.

[0028] Further, the fixed seat is fixedly connected to the transmission gear support. The transmission gear is connected to the transmission gear support and rotates around the connection point; the symmetrically arranged transmission gears can generate first-order inertance behavior under the drive of the driving gear shaft.

[0029] As a preferred technical solution, the upper part of the fixed seat is fixedly connected to the transmission gear support.

[0030] Further, the transmission gear support is connected to the inertial flywheel. The inertial flywheel is rigidly connected to the transmission gear and rotates coaxially with the transmission gear around the connection point; the symmetrically arranged inertial flywheels can rotate as the transmission gear rotates, thereby generating second-order inertance behavior.

[0031] As a preferred technical solution, the viscous fluid is silicone oil and can be replaced according to requirements.

[0032] One of the technical solutions of the present invention is to provide a method for using the above-mentioned inertance-negative stiffness multi-stage tuned vibration damping system based on butterfly viscous damping. The method includes the following steps:

[0033] When the system is working, the driving shaft transmits the horizontal displacement to the driving gear shaft through the spring, causing the driving gear shaft to move;

[0034] When the driving gear shaft moves to the left from the equilibrium position and before reaching the left extreme displacement, the right transmission gear does not rotate. Therefore, all the devices on the right do not work at this time. The left transmission gear rotates forward, and the left inertial flywheel also rotates forward. Both can generate inertia coefficients and drive the left lead screw to move to the right at the same time. The rightward movement of the left lead screw drives the left nut to rotate forward. At this time, the forward rotation of the nut is transmitted to the left rotating inner cylinder through the left one-way bearing. When the rotating inner cylinder rotates, it generates inertia behavior due to its own moment of inertia and generates damping by driving the viscous fluid to undergo shear deformation at the same time.

[0035] During the process of the driving gear shaft moving to the right from the left extreme displacement and returning to the equilibrium position, the right transmission gear does not rotate. Therefore, all the devices on the right do not work at this time. The left transmission gear rotates backward, and the left inertial flywheel also rotates backward. Both can generate inertia coefficients and drive the left lead screw to move to the left at the same time. The leftward movement of the left lead screw drives the left nut to rotate backward. At this time, the backward rotation of the left nut cannot be transmitted to the left rotating inner cylinder through the left one-way bearing. At this time, the one-way rotating inertia-viscous damping subsystem on the left does not work.

[0036] When the driving gear shaft moves to the right again from the equilibrium position and before reaching the right extreme displacement, the left transmission gear does not rotate. Therefore, all the devices on the left do not work at this time. The right transmission gear rotates forward, and the right inertial flywheel also rotates forward. Both can generate inertia coefficients and drive the right lead screw to move to the left at the same time. The leftward movement of the right lead screw drives the right nut to rotate forward. At this time, the forward rotation of the right nut is transmitted to the right rotating inner cylinder through the right one-way bearing. When the right rotating inner cylinder rotates, it generates inertia behavior due to its own moment of inertia and generates damping by driving the viscous fluid to undergo shear deformation at the same time.

[0037] During the process of the driving gear shaft moving to the left from the right extreme displacement and returning to the equilibrium position, the left transmission gear does not rotate. Therefore, all the devices on the left do not work at this time. The right transmission gear rotates backward, and the right inertial flywheel also rotates backward. Both can generate inertia coefficients and drive the right lead screw to move to the right at the same time. The rightward movement of the right lead screw drives the right nut to rotate backward. At this time, the backward rotation of the right nut cannot be transmitted to the right rotating inner cylinder through the right one-way bearing. At this time, the one-way rotating inertia-viscous damping subsystem on the right does not work.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) The present invention realizes the butterfly viscous damping constitutive relationship by using a symmetrically arranged one-way parallel type rotating inertia-viscous damping system (one-way bearing, ball screw mechanism) and a gear rack mechanism (transmission gear, drive gear shaft and screw as rack); its damping behavior only appears in the second and fourth quadrants, and in the process of vibration control, it can not only dissipate vibration energy but also provide an equivalent negative stiffness effect; and since there is no damping in the first and third quadrants, the damping output is 0 when it is in the same direction as the structure's own restoring force, and provides damping force in the opposite direction, which is conducive to reducing the structure's own restoring force, thereby significantly improving the control effect of the peak acceleration response of the structure;

[0040] (2) The spring in the present invention is conducive to amplifying the input horizontal displacement of the device, that is, amplifying the displacement of the drive shaft to the displacement of the drive gear shaft, and then amplifying the horizontal displacement of the butterfly viscous damper, so that it produces a stronger energy dissipation effect, which is conducive to overcoming the disadvantage of the butterfly viscous damper that the energy dissipation capacity is reduced due to the lack of damping effect in the second and fourth quadrants;

[0041] (3) The present invention can realize multi-level inertia capacity behavior through the coordinated work of the transmission gear, the inertia flywheel and the unidirectional rotating inertia capacity-damping system, and realize multi-level tuning of the structure through the series springs, which is conducive to widening the vibration control frequency band and significantly improving the system's adaptability to external excitation frequency; combining the inertia capacity unit and the spring unit, further improving the deformation amplification effect of the damping device and realizing multi-level efficiency enhancement of energy dissipation;

[0042] (4) The inertial behavior generated by the present invention has a dynamic negative stiffness characteristic, which, together with the equivalent negative stiffness provided by the butterfly viscous damping, provides an enhanced negative stiffness for the vibration control of the structure, which can reduce the overall stiffness of the controlled structure and make its natural frequency deviate from the external excitation frequency, which is beneficial to the efficient vibration reduction of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Schematic diagram of the equilibrium position structure of the inertia-negative stiffness multi-stage tuned vibration reduction system based on butterfly viscous damping in Example 1 of the present invention;

[0044] Figure 2 Schematic diagram of force-displacement of the viscous damping part in Example 1 of the present invention;

[0045] Figure 3 Schematic diagram of force-displacement of the inertia portion in Example 1 of the present invention;

[0046] Figure 4 Schematic diagram of force-displacement of the tuning spring part in Example 1 of the present invention;

[0047] Figure 5 Schematic diagram of the equilibrium position structure of the inertia-negative stiffness multi-stage tuned vibration reduction system based on butterfly viscous damping in Example 2 of the present invention.

[0048] Description of the markings in the figure:

[0049] 1 - Fixed outer cylinder, 2 - Viscous fluid, 3 - Thrust bearing, 4 - Rotating inner cylinder, 5 - One-way bearing, 6 - Nut, 7 - Lead screw, 8 - Ball, 9 - Structural plate, 10 - Connecting bolt, 11 - Inertia flywheel, 12 - Transmission gear, 13 - Connection point, 14 - Driving gear shaft, 15 - Transmission gear support, 16 - Fixed seat, 17 - Erbium ring, 18 - Driving shaft, 19 - Spring. Specific implementation mode

[0050] The present invention will be described in detail below in conjunction with specific embodiments. These embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments.

[0051] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are used to describe common objects, and only represent different instances referring to the same object, rather than implying that the objects described in this way must be in a given order, whether in terms of time, space, sorting, or any other way.

[0052] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0053] Embodiment 1:

[0054] A kind of inertia - negative stiffness multi - stage tuned vibration reduction system based on butterfly viscous damping, as Figure 1As shown in the figure, it includes a pair of unidirectional rotary inertance-viscous damping subsystems arranged symmetrically, a pair of transmission gears 12, as well as a fixed seat 16, a driving gear shaft 14 and a spring 19. The lower part of the fixed seat 16 is fixedly connected to the structural bottom plate, and the upper part is fixedly connected to the fixed outer cylinder 1. In this embodiment, a groove is provided in the upper part of the fixed seat 16, and the fixed seat 16 is clamped to the fixed outer cylinder 1 through the groove; the fixed seat 16 is used to fix the relative positions of the components in the whole system;

[0055] The unidirectional rotary inertance-viscous damping subsystem includes a fixed outer cylinder 1. A ball screw mechanism is arranged inside the fixed outer cylinder 1. The ball screw mechanism extends out of the fixed outer cylinder 1. A rotating inner cylinder 4 is arranged inside the fixed outer cylinder 1 and on the inner side of the ball screw mechanism. The outer end of the rotating inner cylinder 4 is connected to the ball screw mechanism through a one-way bearing 5. The space between the rotating inner cylinder 4 and the side wall of the fixed outer cylinder 1 is filled with a viscous fluid 2;

[0056] The extended end of the ball screw mechanism meshes with the transmission gear 12. The transmission gear 12 meshes with the driving gear shaft 14. The driving gear shaft 14 is connected to the structural top plate through a spring 19;

[0057] The ball screw mechanism includes a nut 6, a screw rod 7 and balls 8. The screw rod 7 extends into the nut 6 and the rotating inner cylinder 4. The space between the screw rod 7 and the side wall of the nut 6 is filled with balls 8;

[0058] A structural plate 9 is arranged inside the fixed outer cylinder 1. The screw rod 7 extends outside the structural plate 9. The outer end of the nut 6 is fixedly connected to the structural plate 9 through a connecting bolt 10, and the two move together; both ends of the structural plate 9 are connected to the fixed outer cylinder 1 through two thrust bearings 3. The thrust bearings 3 can limit the translation between the structural plate 9 and the fixed outer cylinder 1, but do not limit the rotation;

[0059] The outer end of the rotating inner cylinder 4 is connected to the nut 6 through a one-way bearing 5, and the inner end is connected to the fixed outer cylinder 1 through a thrust bearing 3; the forward rotation of the nut 6 can be transmitted to the rotating inner cylinder 4 through the one-way bearing 5, and the reverse rotation cannot;

[0060] The viscous fluid 2 can be replaced according to requirements. In this embodiment, silicone oil is selected;

[0061] The symmetrically arranged unidirectional rotary inertance-viscous damping subsystems can generate butterfly viscous damping and third-order inertance behavior located in the second and fourth quadrants of the force-displacement plane under the drive of the driving gear shaft 14;

[0062] The upper part of the fixed seat 16 is fixedly connected to the transmission gear support 15. The transmission gear 12 is connected to the transmission gear support 15 and rotates around the connection point 13; the symmetrically arranged transmission gears 12 can generate first-order inertance behavior under the drive of the driving gear shaft 14;

[0063] The transmission gear support 15 is connected to the inertial flywheel 11. The inertial flywheel 11 is rigidly connected to the transmission gear 12 and rotates coaxially with the transmission gear 12 with the connection point 13 as the center. The symmetrically arranged inertial flywheels 11 can rotate with the rotation of the transmission gear 12, thereby generating a secondary inertia capacitance behavior.

[0064] The left end surface of the drive gear shaft 14 is provided with teeth, and the tooth pitch is smaller than the center distance of the symmetrically arranged transmission gears 12. The extended end surface of the lead screw 7 is provided with teeth. The upper part of the transmission gear 12 meshes with the left end of the drive gear shaft 14, and the lower part meshes with the extended end of the lead screw 7.

[0065] The right end of the drive gear shaft 14 extends into the drive shaft 18 to keep the movements of the drive gear shaft 14 and the drive shaft 18 on the same straight line. A groove is opened at the left end of the drive shaft 18 for the right end of the drive gear shaft 14 to move within the drive shaft 18. The drive shaft 18 is used to drive the entire system to work.

[0066] The drive gear shaft 14 and the drive shaft 18 are connected by a spring 19. An erbium ring 17 is provided at the right end of the drive shaft 18, and the erbium ring 17 is connected to the structural top plate. The horizontal force acting on the drive shaft 18 is transmitted to the drive gear shaft 14 through the spring 19. The drive shaft 18 and the drive gear shaft 14 are connected by the spring 19, which can amplify the horizontal displacement of the drive gear shaft 14, that is, the horizontal displacement of the drive gear shaft 14 is greater than the horizontal displacement of the drive shaft 18.

[0067] In this embodiment, the spring 19 is a single ordinary spring. When the ordinary spring is in a plastic state under tension, stiffness softening will occur, and a corresponding nonlinear effect will be generated. The spring 19 is sleeved on the drive gear shaft 14. There are protrusions on the drive gear shaft 14. The left end of the spring 19 is fixed to the protrusion of the drive gear shaft 14, and the right end is fixed to the left end of the drive shaft 18.

[0068] The usage method of the above inertia capacitance - negative stiffness multi - stage tuned vibration damping system based on the butterfly viscous damping is as follows:

[0069] When the system is working, the drive shaft 18 transmits the horizontal displacement to the drive gear shaft 14 through the spring 19, causing the drive gear shaft 14 to move.

[0070] When the driving gear shaft 14 moves leftward from the equilibrium position and before reaching the left extreme displacement, the right transmission gear 12 does not rotate. Therefore, all the devices on the right do not work at this time. The left transmission gear 12 rotates counterclockwise, and the left inertial flywheel 11 also rotates counterclockwise. Both can generate inertia coefficients and simultaneously drive the left lead screw 7 to move rightward. The rightward movement of the left lead screw 7 drives the left nut 6 to rotate forward. At this time, the forward rotation of the nut 6 is transmitted to the left rotating inner cylinder 4 through the left one-way bearing 5. When the rotating inner cylinder 4 rotates, it generates inertia behavior due to its own moment of inertia and simultaneously generates damping by driving the viscous fluid 2 to undergo shear deformation.

[0071] During the process of the driving gear shaft 14 moving rightward from the left extreme displacement back to the equilibrium position, the right transmission gear 12 does not rotate. Therefore, all the devices on the right do not work at this time. The left transmission gear 12 rotates clockwise, and the left inertial flywheel 11 also rotates clockwise. Both can generate inertia coefficients and simultaneously drive the left lead screw 7 to move leftward. The leftward movement of the left lead screw 7 drives the left nut 6 to rotate reversely. At this time, the reverse rotation of the left nut 6 cannot be transmitted to the left rotating inner cylinder 4 through the left one-way bearing 5, and the one-way rotating inertia-viscous damping subsystem on the left does not work at this time.

[0072] When the driving gear shaft 14 moves rightward again from the equilibrium position and before reaching the right extreme displacement, the left transmission gear 12 does not rotate. Therefore, all the devices on the left do not work at this time. The right transmission gear 12 rotates clockwise, and the right inertial flywheel 11 also rotates clockwise. Both can generate inertia coefficients and simultaneously drive the right lead screw 7 to move leftward. The leftward movement of the right lead screw 7 drives the right nut 6 to rotate forward. At this time, the forward rotation of the right nut 6 is transmitted to the right rotating inner cylinder 4 through the right one-way bearing 5. When the right rotating inner cylinder 4 rotates, it generates inertia behavior due to its own moment of inertia and simultaneously generates damping by driving the viscous fluid 2 to undergo shear deformation.

[0073] During the process of the driving gear shaft 14 moving leftward from the right extreme displacement back to the equilibrium position, the left transmission gear 12 does not rotate. Therefore, all the devices on the left do not work at this time. The right transmission gear 12 rotates counterclockwise, and the right inertial flywheel 11 also rotates counterclockwise. Both can generate inertia coefficients and simultaneously drive the right lead screw 7 to move rightward. The rightward movement of the right lead screw 7 drives the right nut 6 to rotate reversely. At this time, the reverse rotation of the right nut 6 cannot be transmitted to the right rotating inner cylinder 4 through the right one-way bearing 5, and the one-way rotating inertia-viscous damping subsystem on the right does not work at this time.

[0074] When the displacement path of the driving gear shaft 14 conforms to harmonic excitation, within one cycle (the driving gear shaft 14 moves from the equilibrium position to the left extreme - from the left extreme to the right extreme - from the right extreme back to the equilibrium position), as Figure 2 shown, the force-displacement curve of the viscous damping part in the unidirectional rotary inertia-viscous damping subsystem is a butterfly viscous damping curve, which has energy dissipation capacity and equivalent negative stiffness; as Figure 3 shown, the force-displacement curve of the inertia part is a straight line. The force-displacement curves of the inertia parts provided by the transmission gear 12 and the inertial flywheel 11 are also straight lines, but since the inertia coefficients provided by the rotating inner cylinder 4, the transmission gear 12, and the inertial flywheel 11 are different, the slopes of their respective force-displacement curves are not the same. As Figure 4 shown, the force-displacement curve of the tuning spring part provided by the spring 19 shows positive stiffness, but its positive stiffness value decreases with the increase of displacement, showing a softening curve.

[0075] Embodiment 2:

[0076] An inertia-negative stiffness multi-stage tuned vibration reduction system based on butterfly viscous damping, as Figure 5 shown, is basically the same as Embodiment 1, except that the connection method between the driving gear shaft 14 and the driving shaft 18 through the spring 19 is different. The specific structure is as follows:

[0077] The spring 19 is selected as a spring group formed by multiple ordinary springs. The vertical components of the forces exerted by the ordinary springs in the spring group cancel each other out, and the horizontal components are superimposed on each other, and the horizontal stiffness changes non-linearly with displacement. The spring group as a whole exhibits a non-linear effect. The spring 19 is vertically symmetrically arranged on both sides of the driving gear shaft 14. The proximal end of the spring 19 is fixed on the driving gear shaft 14, and the distal end is fixed on the inner side of the groove body of the driving shaft 18.

[0078] The present invention is suitable for installation between structural layers and isolation layers. The generated multi-stage inertia behavior can provide multi-stage adaptive inertia coefficients and multi-stage dynamic negative stiffness characteristics, and then cooperate with the tuning spring to achieve the multi-stage tuned vibration absorption function; in addition, the generated butterfly viscous damping in the second and fourth quadrants can provide equivalent negative stiffness while dissipating vibration energy, avoiding the amplification of the structural acceleration response caused by the high damping control force in the first and third quadrants, significantly improving the deformation efficiency and amplitude of the damping unit in the multi-stage tuned vibration reduction system, and realizing more significant damping non-linear enhancement.

[0079] The above description of the embodiments is to enable those of ordinary skill in the art to understand and use the invention. Obviously, those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A butterfly viscous damping-based inertia-negative stiffness multi-stage tuned vibration reduction system, characterized in that: The system comprises a symmetrically arranged one-way rotating inertia-viscous damping subsystem, a transmission gear (12), a fixed seat (16), a driving gear shaft (14) and a spring (19); The one-way rotating inertia-viscous damping subsystem comprises a fixed outer cylinder (1) and a rotating inner cylinder (4); a ball screw mechanism is arranged in the fixed outer cylinder (1), and the ball screw mechanism extends from the fixed outer cylinder (1); the rotating inner cylinder (4) is arranged in the fixed outer cylinder (1) and on one side of the ball screw mechanism; one end of the rotating inner cylinder (4) is connected to the ball screw mechanism via a one-way bearing (5); and the space between the rotating inner cylinder (4) and the side wall of the fixed outer cylinder (1) is filled with a viscous fluid (2); The extended end of the ball screw mechanism is meshed with a transmission gear (12), the transmission gear (12) is meshed with a drive gear shaft (14), and the drive gear shaft (14) is connected to the structure via a spring (19); One side of the fixing seat (16) is fixedly connected to the structure, and the other side is fixedly connected to the fixed outer cylinder (1); The ball screw mechanism comprises a nut (6), a screw rod (7) and a ball (8); the screw rod (7) extends into the nut (6) and the rotating inner cylinder (4); and the space between the screw rod (7) and the side wall of the nut (6) is filled with the ball (8); One end surface of the driving gear shaft (14) is provided with teeth, the tooth spacing being smaller than the center distance of the symmetrically arranged transmission gears (12), and the extended end surface of the screw rod (7) is provided with teeth, one side of the transmission gear (12) is meshed with one end of the driving gear shaft (14), and the other side is meshed with the extended end of the screw rod (7); The fixed seat (16) is fixedly connected to the transmission gear support (15), and the transmission gear (12) is connected to the transmission gear support (15) and rotates with the connection point (13) as the center of the circle.

2. According to claim 1, the inertia-negative stiffness multi-stage tuned vibration reduction system based on butterfly viscous damping is characterized in that: A structural plate (9) is arranged inside the fixed outer cylinder (1), the screw rod (7) extends out of the structural plate (9), one end of the nut (6) is fixedly connected to the structural plate (9), and the structural plate (9) is connected to the fixed outer cylinder (1) via a thrust bearing (3).

3. The inertia-negative stiffness multi-stage tuned vibration reduction system based on butterfly viscous damping according to claim 1 is characterized in that: One end of the rotating inner cylinder (4) is connected to a nut (6) via a one-way bearing (5), and the other end is connected to a fixed outer cylinder (1) via a thrust bearing (3).

4. The inertia-negative stiffness multi-stage tuned vibration reduction system based on butterfly viscous damping according to claim 1 is characterized in that: The other end of the driving gear shaft (14) extends into the driving shaft (18), and a groove is formed at one end of the driving shaft (18); The driving gear shaft (14) is connected to the driving shaft (18) via a spring (19), and one end of the driving shaft (18) is connected to the structure.

5. The inertia-negative stiffness multi-stage tuned vibration reduction system based on butterfly viscous damping according to claim 4 is characterized in that: The spring (19) is sleeved on the driving gear shaft (14), and a protrusion is provided on the driving gear shaft (14). One end of the spring (19) is fixed to the protrusion of the driving gear shaft (14), and the other end is fixed to one end of the driving shaft (18).

6. The inertia-negative stiffness multi-stage tuned vibration reduction system based on butterfly viscous damping according to claim 4 is characterized in that: The spring (19) is vertically symmetrically arranged on both sides of the driving gear shaft (14); one end of the spring (19) is fixed to the driving gear shaft (14), and the other end is fixed to the inner side of the groove body of the driving shaft (18).

7. The inertia-negative stiffness multi-stage tuned vibration reduction system based on butterfly viscous damping according to claim 1 is characterized in that: The transmission gear support (15) is connected to the inertia flywheel (11), and the inertia flywheel (11) is rigidly connected to the transmission gear (12) and rotates coaxially with the transmission gear (12) with the connection point (13) as the center.

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