A quasi-zero stiffness mechanism based viscous damper

Abstract

The application discloses a viscous damper based on a quasi-zero stiffness mechanism and relates to the technical field of flexible mechanical arm vibration control for machining. The device further suppresses the wide-frequency vibration of a controlled object generated in a machining process by introducing mass and damping into the controlled object, and improves work efficiency and stability. The mass module and the connecting rod assembly adopt a modular design, and corresponding mass and size can be installed according to required viscous damper parameters, so that the damper is conveniently applied to different modal vibration modes. The quasi-zero stiffness mechanism can provide stable support force for the mass block of the viscous damper moving in the vertical direction, offset the influence of gravity within a certain motion range, ensure that the damper can normally suppress wide-frequency vibration, widen the vibration reduction frequency range of a traditional dynamic vibration absorber and eliminate the use scene limitation of a single viscous damper.

Description

Technical Field

[0001] This invention relates to the field of robots and robotic automated devices, and more particularly to the field of vibration control for flexible robotic arms for machining, specifically to a viscous damper based on a quasi-zero stiffness mechanism. Background Technology

[0002] In traditional automated industrial production, industrial robot arms typically employ rigid design standards to minimize motion errors and mechanical vibrations, ensuring stable operation. However, traditional rigid robotic arms suffer from problems such as high mass, low speed, high energy consumption, and poor flexibility, failing to meet the demands of today's high-efficiency production. With technological advancements, next-generation robot technology demands lightweight construction, high speed, low energy consumption, and minimal contact impact. Therefore, robotic arms are increasingly adopting flexible, lightweight materials and designed with slender structures. When a flexible robotic arm system moves along a planned path, insufficient rigidity can cause small-deformation elastic vibrations. If further disturbed by external factors, the increased elastic deformation only exacerbates the vibration. Vibration in flexible robotic arms has become a major obstacle to achieving high speed and high precision. Therefore, suppressing the vibration generated during the movement of flexible robotic arms is an urgent problem that needs to be solved.

[0003] In automated equipment, prolonged exposure to mechanical vibration can lead to fatigue damage of equipment components, thus shortening the equipment's lifespan. Furthermore, for machining processes requiring high precision, mechanical vibration can also affect the stability and accuracy of the equipment, resulting in decreased work efficiency. Research indicates that vibration problems are primarily caused by insufficient damping in the mechanical structure. As a countermeasure, various dampers that increase the damping of mechanical systems have been invented, the most representative being the dynamic vibration absorber. The dynamic vibration absorber consists of added mass, a spring, and damping, and belongs to the passive vibration damper category for suppressing resonance. Due to its small size, lightweight design, and good vibration damping function, it is widely used in mechanical equipment. However, the dynamic vibration absorber has a narrow operating frequency band; when the absorber deviates from its optimal frequency band, the damping effect is weaker. Therefore, a dynamic vibration absorber targeting a specific mode has little impact on multi-mode broadband vibrations. Additionally, because of the dynamic vibration absorber's own natural frequency, resonance can occur when the vibration frequency approaches its natural frequency, leading to a weakening or even deterioration of the vibration reduction effect. To address these shortcomings, viscous dampers, which only increase the damping of the mechanism, have begun to be applied to vibration damping needs.

[0004] Viscous dampers, as important devices for reducing mechanical vibration, have attracted much attention in the engineering field. Firstly, the basic working principle of viscous dampers is to change the dynamic characteristics of a vibrating system by introducing damping and mass without adding stiffness elements, thereby absorbing and suppressing vibration energy. A well-designed viscous damper can significantly reduce the vibration amplitude of a mechanical system, improving its stability and reliability. Furthermore, viscous dampers can also be applied to energy recovery and noise control. They have the potential to recycle vibration energy and reduce environmental noise, providing new avenues for energy conservation, emission reduction, and environmental protection. In general, energy-dissipating vibration reduction suppresses system vibration by increasing system damping. Compared to dynamic vibration absorption, its vibration suppression effect is less affected by changes in the target modal dynamic parameters, and its wider operating frequency band allows it to produce vibration suppression even under slight disturbances to the controlled object, achieving vibration reduction over a wide frequency range. Additionally, the absence of added stiffness elements avoids resonance phenomena caused by the system's vibration frequency approaching its natural frequency. Therefore, research on viscous dampers not only helps improve the performance and stability of mechanical systems but also has broad application prospects and will play an important role in the engineering field.

[0005] The initially designed viscous damper was used in horizontal motion and rotation devices, thus achieving a wide operating frequency band without the need for additional stiffening elements. However, for controlled objects moving in the direction of gravity, such as flexible robotic arms performing vertical movements, the lack of stiffening elements to support the mass module prevents the viscous damper from functioning properly, limiting its application scenarios. Simply using a spring as the mass module's support element results in the damper having a natural frequency, leading to resonant frequencies and no longer satisfying the requirement for wide-band vibration damping. Therefore, this invention proposes a viscous damper based on a quasi-zero stiffness mechanism. This introduces damping into vertically moving controlled objects, thereby achieving wide-band vibration suppression and increasing the efficiency of the flexible robotic arm. A quasi-zero stiffness mechanism with high static stiffness and low dynamic stiffness is designed to provide stable support for the mass module when stationary. The mechanism's low dynamic stiffness can counteract the gravitational influence of the mass module within a certain range of motion, enabling the viscous damper to achieve vibration suppression in the direction of gravity of the controlled object. Therefore, the addition of a quasi-zero stiffness mechanism can expand the application scenarios and range of viscous dampers, effectively suppressing broadband vibrations of the controlled object in the direction of gravity. Furthermore, to increase the versatility of this damper and enable its application to different mode shapes, this invention implements a modular design for the mass module and connecting rods. Different masses and rod lengths can be adjusted according to different mode shapes, facilitating the analysis of vibration suppression effects under different damper parameters and reducing material and labor costs. Summary of the Invention

[0006] The technical problem this invention aims to solve is to address the shortcomings of the prior art by disclosing a viscous damper based on a quasi-zero stiffness mechanism. This introduces mass and damping into the controlled object, further suppressing broadband vibrations generated during processing and improving work efficiency and stability. The mass module and connecting rod adopt a modular design, allowing for the installation of corresponding masses and dimensions according to the required viscous damper parameters, facilitating the application of this damper to different mode shapes. The quasi-zero stiffness mechanism provides stable support for the vertically moving viscous damper mass module and counteracts the influence of gravity within a certain range of motion, enabling the mass module to operate in a stiffness-free state and ensuring that the damper can effectively suppress broadband vibrations.

[0007] To achieve the above objectives, the present invention employs the following technical solution:

[0008] This invention proposes a viscous damper based on a quasi-zero stiffness mechanism, characterized in that it comprises a damping component, a quasi-zero stiffness component, and a clamping component, wherein:

[0009] As an important component of viscous dampers, the damping component applies the principle of viscous damping. The mass module moves in the closed space formed by the shell to generate damping force to suppress the vibration of the controlled body. It is the basic functional module of the viscous damper. The damping component consists of a mass module and a shell assembly. The mass module mainly includes a mass base (3) and several additional masses (2). The mass base (3) and the additional masses (2) have through holes for precision assembly. The required mass combination can be fixed into a whole by bolts. The mass base (3) is designed with threaded holes for connection with the quasi-zero stiffness component. The shell mainly includes an upper shell (1), a base (14), a washer (13) and a sealing ring (12). The base (14) is designed with a sealing ring (12) slot for placing the sealing ring (12). The washer (13) is clamped between the upper shell (1) and the base (14). The upper shell (1), the washer (13) and the base (14) are fixed together by bolts.

[0010] The quasi-zero stiffness component is used to support the mass module and, through the combination of positive and negative stiffness springs, makes the stiffness of the mass module negligible during vibration. The quasi-zero stiffness component consists of an upper connecting block (4), a sliding sleeve (5), a guide rod (10), a connecting rod assembly (7), a connecting pin (9), a lower connecting block (11), a horizontal tension spring (8), and a vertical compression spring (6); the upper connecting block (4) is fixed to the mass base (3) according to the positioning surface; the sliding sleeve (5) is embedded in the upper connecting block (4) through an interference fit and forms a sliding pair on the guide rod (10); the connecting rod assembly (7) forms a rotating pair with the upper connecting block (4) through bolts; The rod assemblies (7) are connected by connecting pins (9) to form a rotating pair; the connecting rod assembly (7) and the lower connecting block (11) are connected by bolts to form a rotating pair; the lower connecting block (11) is fixed to the base (14) according to the positioning surface; the connecting rod assembly (7) is also fixed to the lower connecting block (11) by threaded connection through the positioning surface; the vertical compression spring (6) is sleeved on the guide rod (10), and the horizontal tension spring (8) is embedded in the groove of the connecting pin (9) through a hook, and the two horizontal springs are symmetrically distributed on both sides of the connecting rod assembly (7). The connecting rod assembly (7) mainly includes an upper connecting rod (7-a) and a lower connecting rod (7-b), and the two parts are fixed together by bolts.

[0011] The main function of the clamping component is to fix the viscous damper to the controlled object. The clamping component is mainly composed of a base (14) and a clamp (16). The base (14) of the outer shell is connected to the threaded hole on the clamp (16) by bolts through the through hole. The controlled object (15) is embedded in the groove of the clamp (16) through the positioning surface and clamped between the base (14) and the clamp (16).

[0012] The viscous damper based on a quasi-zero stiffness mechanism is characterized in that: the viscous damper is composed of an outer shell assembly, a mass module, and a medium. A certain radial gap is left between the upper outer shell (1) and the mass base (3) in the mass module, the gap being determined by the required damping, and the added mass (2) does not affect the damping magnitude. When the viscous damper vibrates along with the controlled object (15), the mass module moves axially, forcing the medium to flow through the radial gap. During this process, due to the viscosity of the medium, a damping force is provided, which hinders the axial movement of the mass module and converts part of the kinetic energy of the mass module into heat energy dissipation, thereby dissipating vibration energy and achieving the effect of vibration suppression. The base (14) is designed with a stop and the inner side of the upper shell (1) is designed with an interference fit, which plays a positioning role to ensure the coaxiality of the inner side of the upper shell (1) and the base (14), while preventing the leakage of the medium inside the viscous damper. According to the internal pressure, the outer diameter of the sealing ring (12) matches the groove on the base (14), leaving a gap on the inner side. The interference fit between the base (14) and the upper shell (1), the use of the sealing ring (12) and the gasket (13) together constitute the closed space inside the viscous damper, which can effectively prevent the leakage of the internal medium, thereby ensuring that the viscous damper can work effectively for a long time.

[0013] The viscous damper based on a quasi-zero stiffness mechanism is characterized in that: the mass module adopts a modular design, and an additional mass (2) is added on the basis of the mass base (3); the mass base (3) is designed with a boss, and a groove is designed on the additional mass (2). This stop positioning can ensure the accuracy of assembly and ensure that the center of gravity of the mass module moves on the central axis of the viscous damper, thereby avoiding the bending moment caused by the center of gravity shift, which affects the vibration reduction effect of the viscous damper or even damages other components; the mass base (3) is designed with a threaded hole for connecting with the quasi-zero stiffness component and ensures coaxiality with the mass module; the base (14) is designed with a threaded hole for connecting with the quasi-zero stiffness component and ensures coaxiality with the boss.

[0014] The viscous damper based on a quasi-zero stiffness mechanism is characterized in that: the quasi-zero stiffness component is based on the principle of quasi-zero stiffness structure, and generates negative stiffness through a horizontal tension spring (8) and provides positive stiffness through a vertical compression spring (6). The parallel connection of positive and negative stiffness elements and the structure of the linkage assembly (7) generate the characteristics of high static and low dynamic of the quasi-zero stiffness component; the four equal-length linkage assemblies (7) in the quasi-zero stiffness component form a rhombic structure. When the mass module is out of the equilibrium position, the force given to the mass module by the linkage assembly (7) offsets the influence of gravity of the mass module within a certain range of motion, so that the viscous damper can realize the vibration suppression function in the direction of gravity of the controlled object; the quasi-zero stiffness component adopts a modular design. The linkage assembly (7) is composed of an upper linkage (7-a) and a lower linkage (7-b). The two form a sliding pair through the positioning surface and are fixed together by bolts to form a quasi-zero stiffness mechanism with different rod lengths, thereby meeting the needs of different working stroke ranges of the viscous damper.

[0015] The beneficial effects of the technical solution of the present invention are as follows:

[0016] (1) This invention utilizes the principle of viscous damping to design a viscous damper. The medium flowing through the radial gap between the mass module and the upper shell generates corresponding damping, which has a significant effect on suppressing processing vibration. Energy-dissipating vibration reduction suppresses system vibration by increasing system damping. Compared with commonly used dynamic vibration absorption methods, its vibration suppression effect is less affected by changes in the target modal dynamic parameters, and its wider operating frequency band can still produce a vibration suppression effect when the controlled object is slightly disturbed, achieving vibration reduction in a wide frequency range;

[0017] (2) The present invention can apply the viscous damper to the vibration suppression of the controlled object in the direction of gravity through the quasi-zero stiffness component. It can provide stable support for the mass module of the viscous damper, while offsetting the gravity influence of the mass module within a certain range of motion. This enables the viscous damper to achieve a wide-band vibration suppression function in the direction of gravity of the controlled object, and avoids the resonance phenomenon that affects the vibration suppression effect.

[0018] (3) This invention adopts a modular design principle, with each component integrated into an independent module, facilitating installation and handling. Furthermore, by adding mass, the influence of different damping parameters on vibration suppression can be studied, and the installation and vibration suppression requirements under different gap sizes can be met. Different working stroke ranges can be achieved by changing the length of the quasi-zero stiffness mechanism linkage assembly. And relying on a high-precision positioning surface, the installation accuracy of each component in the device is guaranteed. The three-layer sealing structure of this viscous damper effectively prevents leakage of the internal medium, ensuring a compact structure while providing long-term, effective, and reliable suppression of the vibration of the controlled object.

[0019] (4) In this invention, by combining a viscous damper with a quasi-zero stiffness mechanism, the vibration reduction frequency band of traditional dynamic vibration absorbers is further broadened, and the application scenario limitations of a single viscous damper are eliminated. At the same time, the mass module and linkage assembly are modularly designed, which can be applied to controlled objects under different vibration conditions. This is of great significance for vibration reduction of flexible robotic arms for machining. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a viscous damper based on a quasi-zero stiffness mechanism according to the present invention.

[0021] Figure 2 This is a schematic diagram of the internal structure of a viscous damper based on a quasi-zero stiffness mechanism according to the present invention.

[0022] Figure 3 This is a schematic diagram of the internal structure of a viscous damper based on a quasi-zero stiffness mechanism according to the present invention.

[0023] Figure 4 This is a schematic cross-sectional view of a viscous damper based on a quasi-zero stiffness mechanism according to the present invention.

[0024] Figure 5 This is a schematic diagram of a quasi-zero stiffness structure of a viscous damper based on a quasi-zero stiffness mechanism in this invention.

[0025] Figure 6 This is an assembly diagram of a viscous damper connecting pin based on a quasi-zero stiffness mechanism according to the present invention.

[0026] Figure 7 This is a detailed view of a viscous damper connecting pin based on a quasi-zero stiffness mechanism in this invention.

[0027] Figure 8 This is an assembly diagram of a viscous damper linkage assembly based on a quasi-zero stiffness mechanism according to the present invention.

[0028] The above figure includes: upper shell (1), additional mass (2), mass base (3), upper connecting block (4), sliding sleeve (5), vertical compression spring (6), connecting rod assembly (7), upper connecting rod (7-a), lower connecting rod (7-b), horizontal tension spring (8), connecting pin (9), guide rod (10), lower connecting block (11), sealing ring (12), washer (13), base (14), controlled object (15), and clamp (16). Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and specific examples, but the implementation of the present invention is not limited thereto.

[0030] Combination Figure 1 , Figure 2 , Figure 3 , Figure 4 as well as Figure 5 As shown, the present invention discloses a viscous damper based on a quasi-zero stiffness mechanism, characterized in that it comprises a damping component, a quasi-zero stiffness component, and a clamping component, wherein:

[0031] As a crucial component of a viscous damper, the damping element primarily functions to suppress the vibration of the controlled object through the damping force generated by the movement of the mass module within the medium. The damping element consists of a mass module and a housing assembly. The mass module mainly comprises a mass base 3 and several additional masses 2. The mass base 3 and the additional masses 2 have through holes for precision assembly, allowing the required mass combinations to be fixed together as a whole using bolts. The mass base 3 is designed with threaded holes for connection to a quasi-zero stiffness component. The housing mainly comprises an upper housing 1, a base 14, a washer 13, and a sealing ring 12. The base 14 is designed with a groove for the sealing ring 12 to accommodate it. The washer 13 is clamped between the upper housing 1 and the base 14. The upper housing 1, washer 13, and base 14 are fixed together using bolts.

[0032] The quasi-zero stiffness component supports the mass module and, through the combination of positive and negative stiffness springs, makes the stiffness of the mass module negligible during vibration. The quasi-zero stiffness component consists of an upper connecting block 4, a sliding sleeve 5, a guide rod 10, a connecting rod assembly 7, a connecting pin 9, a lower connecting block 11, a horizontal tension spring 8, and a vertical compression spring 6. The upper connecting block 4 is fixed to the mass base 3 according to its positioning surface. The sliding sleeve 5 is inserted into the upper connecting block 4 through an interference fit and forms a sliding joint on the guide rod 10. The connecting rod assembly 7 forms a rotating joint with the upper connecting block 4 through bolts. The connecting rod assemblies 7 also form rotating joints with each other through connecting pins 9. The connecting rod assembly 7 and the lower connecting block 11 form a rotating joint through bolts. The lower connecting block 11 is fixed to the base 14 according to its positioning surface. The connecting rod assembly 7 is also threadedly fixed to the lower connecting block 11 through its positioning surface. The vertical compression spring 6 is sleeved on the guide rod 10, such as... Figure 6 and Figure 7 As shown, the horizontal tension spring 8 is embedded in the groove of the connecting pin 9 via a hook, and the two horizontal springs are symmetrically distributed on both sides of the connecting rod assembly 7. Figure 8 As shown, the linkage assembly 7 mainly includes an upper linkage 7-a and a lower linkage 7-b, which are fixed together by bolts.

[0033] The main function of the clamping component is to fix the viscous damper to the controlled object. The clamping component is mainly composed of a base 14 and a clamping plate 16, which are connected by bolts through the through holes of the base 14 and threaded holes on the clamping plate 16. The controlled object 15 is embedded in the groove of the clamping plate 16 through the positioning surface and clamped between the base 14 and the clamping plate 16.

[0034] The viscous damper based on a quasi-zero stiffness mechanism is characterized in that: the viscous damper is composed of an outer shell assembly, a mass module, and a medium. A certain radial gap is maintained between the upper outer shell 1 and the mass base 3 in the mass module. This gap is determined by the required damping, and the added mass 2 does not affect the damping magnitude. When the viscous damper vibrates along with the controlled object 15, the mass module moves axially, forcing the medium to flow through the radial gap. During this process, due to the viscosity of the medium, a damping force is provided, which hinders the axial movement of the mass module and converts a portion of the mass module's kinetic energy into heat dissipation, thereby dissipating vibration energy and achieving vibration suppression. The base 14 is designed with a stop and an interference fit with the inner side of the upper shell 1, which serves to position and ensure the coaxiality of the inner side of the upper shell 1 and the base 14, while preventing leakage of the medium inside the viscous damper. Under the action of internal pressure, the outer diameter of the sealing ring 12 fits with the groove on the base 14, leaving a gap on the inner side. The interference fit between the base 14 and the upper shell 1, the use of the sealing ring 12 and the gasket 13 together constitute a closed space inside the viscous damper, which can effectively prevent leakage of the internal medium, thereby ensuring that the viscous damper can work effectively for a long time.

[0035] The viscous damper based on a quasi-zero stiffness mechanism is characterized by: a modular design for the mass module, with an additional mass 2 added to the mass base 3; a boss on the mass base 3 and a corresponding groove on the additional mass 2, which ensures precise assembly and that the center of gravity of the mass module moves on the central axis of the viscous damper, thereby avoiding bending moments caused by center of gravity shift, which could affect the damping effect of the viscous damper or even damage other components; a threaded hole for the mass base 3 to connect with the quasi-zero stiffness component, ensuring coaxiality with the mass module; and a threaded hole for the base 14 to connect with the quasi-zero stiffness component, ensuring coaxiality with the boss.

[0036] The viscous damper based on a quasi-zero stiffness mechanism is characterized in that: the quasi-zero stiffness component is based on the principle of quasi-zero stiffness structure, generating negative stiffness through a horizontal tension spring 8 and providing positive stiffness through a vertical compression spring 6. The parallel connection of positive and negative stiffness elements and the linkage assembly 7 structure create the high static and low dynamic characteristics of the quasi-zero stiffness component; the four equal-length linkage assemblies 7 in the quasi-zero stiffness component form a rhombic structure. When the mass module is out of equilibrium, the force applied to the mass module by the linkage assembly 7 offsets the influence of gravity of the mass module within a certain range of motion, enabling the viscous damper to achieve vibration suppression function in the direction of gravity of the controlled object; the quasi-zero stiffness component adopts a modular design, and the linkage assembly 7 consists of an upper linkage 7-a and a lower linkage 7-b. The two form a sliding pair through a positioning surface and are fixed together by bolts to form a quasi-zero stiffness mechanism with different rod lengths, thereby meeting the requirements of different working stroke ranges of the viscous damper.

[0037] This invention is not limited to the specific embodiments described above. It should be noted that those skilled in the art can make several improvements and substitutions without departing from the technical principles of this invention, and these improvements and substitutions should also be considered within the scope of protection of this invention.

Claims

1. A quasi-zero stiffness mechanism based viscous damper, characterized in that, It comprises damping components, quasi-zero stiffness components and clamping components, wherein: The damping components are important components of the viscous damper, which suppress the vibration of the controlled object by the damping force generated by the movement of the mass module in the medium, and the damping components are composed of the mass module and the shell assembly; the mass module comprises a mass base (3) and a plurality of additional masses (2); the mass base (3) and the additional masses (2) have through holes for fine assembly, and the required mass base (3) and additional masses (2) can be fixed as a whole by bolts; the mass base (3) is designed with threaded holes connected with the quasi-zero stiffness components; the shell comprises an upper shell (1), a base (14), a gasket (13) and a sealing ring (12); the base (14) is designed with a sealing ring (12) clamping groove for placing the sealing ring (12); the gasket (13) is clamped between the upper shell (1) and the base (14); the upper shell (1), the gasket (13) and the base (14) are fixed by bolts; The quasi-zero stiffness components are used for supporting the mass module, and can make the stiffness of the mass module negligible when vibrating by the combination of positive and negative stiffness springs; the quasi-zero stiffness components are composed of an upper connecting block (4), a sliding sleeve (5), a guide rod (10), a connecting rod assembly (7), a connecting pin (9), a lower connecting block (11), a horizontal tension spring (8) and a vertical compression spring (6); the upper connecting block (4) is fixed with the mass base (3) according to the positioning surface; the sliding sleeve (5) is embedded in the upper connecting block (4) by interference fit, and a moving pair is formed on the guide rod (10); the connecting rod assembly (7) and the upper connecting block (4) constitute a rotating pair through bolts; the connecting rod assembly (7) constitutes a rotating pair through the connecting pin (9); the connecting rod assembly (7) and the lower connecting block (11) constitute a rotating pair through bolts; the lower connecting block (11) is fixed with the base (14) according to the positioning surface; the vertical compression spring (6) is sleeved on the guide rod (10), and the horizontal tension spring (8) is embedded in the groove of the connecting pin (9) through the hook, the two horizontal springs are symmetrically distributed on both sides of the connecting rod assembly (7), the connecting rod assembly (7) comprises an upper connecting rod (7-a) and a lower connecting rod (7-b), which constitute a moving pair through the positioning surface and are fixed together by bolts, The clamping components fix the viscous damper and the controlled object together, and the clamping components are composed of the base (14) and the clamping piece (16), which are connected by the through hole bolts of the base (14) of the shell and the threaded holes on the clamping piece (16); the controlled object (15) is embedded in the groove of the clamping piece (16) through the positioning surface and clamped between the base (14) and the clamping piece (16). The viscous damper is composed of a shell assembly, a mass module and a medium, a radial gap is left between the upper shell (1) and the mass base (3) of the mass module, the gap is determined by the required damping, and the additional mass (2) does not affect the damping size, when the viscous damper vibrates with the controlled object (15), the mass module moves axially, forcing the medium to flow through the radial gap, the medium has viscosity to provide damping force, hinder the axial movement of the mass module and convert part of the kinetic energy of the mass module into heat energy dissipation, thereby dissipating vibration energy.

2. A quasi-zero stiffness mechanism based viscous damper according to claim 1, wherein: The base (14) is designed with a shoulder, and the inner side of the upper shell (1) is designed as an interference fit, which plays a positioning role to ensure the coaxiality of the inner side of the upper shell (1) and the base (14), and can prevent the leakage of the internal medium of the viscous damper; according to the internal pressure, the outer diameter of the sealing ring (12) is matched with the groove on the base (14), and a gap is reserved on the inner side; the interference fit of the base (14) and the upper shell (1), the use of the sealing ring (12) and the washer (13) together constitute the closed space inside the viscous damper, prevent internal medium leakage, so as to ensure that the viscous damper can work effectively for a long time.

3. A quasi-zero stiffness mechanism based viscous damper according to claim 1, wherein: The mass module is designed in a modular manner, and the required additional mass (2) is added to the mass base (3); The mass base (3) is designed with a boss, and the additional mass (2) is designed with a groove, the shoulder positioning ensures the assembly accuracy, ensures that the center of gravity of the mass module moves on the central axis of the viscous damper, and the mass base (3) is designed with a threaded hole connected with the quasi-zero stiffness component to ensure coaxiality; the base (14) is designed with a threaded hole connected with the quasi-zero stiffness component to ensure coaxiality.

4. A quasi-zero stiffness mechanism based viscous damper according to claim 1, wherein: The quasi-zero stiffness component is based on the principle of quasi-zero stiffness structure, generates negative stiffness through horizontal tension spring (8), and provides positive stiffness through vertical compression spring (6), generates the characteristics of high static and low dynamic through the parallel connection of positive and negative stiffness elements and the structure of connecting rod assembly (7); the four equal-length connecting rod assemblies (7) in the quasi-zero stiffness component form a diamond structure, when the mass module deviates from the balance position, the force of the connecting rod assembly (7) to the mass module offsets the gravity of the mass module, so that the viscous damper realizes the vibration suppression function in the direction of the gravity of the controlled object; the quasi-zero stiffness component is designed in a modular manner, the connecting rod assembly (7) is composed of upper connecting rod (7-a) and lower connecting rod (7-b), and the quasi-zero stiffness mechanism under different rod lengths is formed, so as to meet the demand of different working stroke range of the viscous damper.

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