A closed stiffness nonlinear disc structure

Abstract

This invention discloses a closed-type stiffness nonlinear disc structure, comprising an upper cover, a lower cover, a support cylinder, and a spring. The upper and lower covers have identical disc-shaped structures, each including a base plate, an elastomer, and a flange ring. The openings of the upper and lower covers face each other, and their flange rings are respectively sealed and fixed to both ends of the support cylinder. The spring is disposed between the upper and lower covers. This invention can directly bear external loads as a support structure, or it can be placed inside an air spring or hydraulic support. It can achieve ultra-low frequency support under various loads, and has the advantages of high load-bearing capacity, compactness, and high reliability. It is suitable for ultra-low frequency vibration control in fields such as precision instruments, aerospace, and shipbuilding.

Description

Technical Field

[0001] This invention belongs to the field of vibration control and structural dynamics technology, specifically relating to a closed stiffness nonlinear disc structure, which is particularly suitable for applications with extremely high requirements for vibration suppression, such as aerospace, shipbuilding, and precision instrument manufacturing. Background Technology

[0002] Vibration isolation systems have wide applications in numerous fields, such as aerospace, building structures, road and bridge construction, and shipboard vibration isolation. The support systems and vibration isolation devices used are also diverse. Typical vibration isolation devices include spring-damped isolators and rubber isolators, which exhibit linear stiffness characteristics. For systems with large loads, they require significant support stiffness, resulting in a high fundamental frequency characteristic of the vibration isolation system. According to vibration theory, the effective operating frequency band of the vibration isolation system is influenced by the fundamental frequency of the support system, and is higher than the natural frequency of the support system. It has a vibration isolation effect when the frequency is doubled. To obtain a wider frequency vibration isolation effect, or for some structures with low self-elastic vibration modes, it is necessary to design an ultra-low frequency vibration isolation system to meet the requirements for low frequency vibration isolation performance.

[0003] Existing vibration isolation systems for ship internal equipment offer good isolation for mid-to-high frequency vibrations. However, low-frequency vibrations caused by some equipment are forced vibrations with a continuous supply of vibrational energy, unable to decay on their own. These vibrations are transmitted through the structure, severely impacting the ship's stealth performance. Vibration isolation is particularly important for ship systems, and an effective way to improve isolation is to reduce the natural frequency of the isolation system. The project "Structural Design and Experimental Study of a Novel High Static and Low Dynamic Stiffness Airbag Vibration Isolation Device" combines a quasi-zero stiffness system with air springs to achieve high static stiffness and low dynamic stiffness. This is a relatively new vibration isolation method that effectively reduces the natural frequency of the support system and achieves good vibration isolation. However, this quasi-zero stiffness system composed of spring structures occupies a large space and requires pre-compressed springs for elastic energy storage, posing a high risk.

[0004] This invention relates to a nonlinear stiffness disc structure that combines positive and negative stiffness characteristics to give the support system extremely low dynamic stiffness at the equilibrium position, achieving ultra-low frequency dynamic characteristics and greatly expanding vibration isolation in the low-frequency range. While maintaining vibration isolation performance, this invention features a compact structure, high space utilization, and wide applicability. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a closed stiffness nonlinear disc structure. By connecting positive and negative stiffness elastic structures in parallel, it can achieve high load-bearing capacity and low stiffness characteristics at the equilibrium position, thereby achieving the effect of ultra-low frequency vibration isolation.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A closed, stiffness-nonlinear disc structure includes an upper cover, a lower cover, a support cylinder, and a spring;

[0008] The upper and lower covers have the same structure and are disc-shaped. Each cover includes a base plate, an elastomer, and a flange ring. The base plate is a circular plate. The elastomer is a hollow frustum with open ends and is made of elastic material. Its smaller end is sealed and coaxially fixed to the base plate, and its larger end is sealed and coaxially fixed to the flange ring.

[0009] The support cylinder is a hollow cylinder with openings at both ends;

[0010] The upper and lower covers have openings facing each other, and their flange rings are respectively sealed and fixed to both ends of the support cylinder to form a sealed cavity;

[0011] The inner wall center of the substrate of the upper and lower covers is provided with a positioning post for cooperating with the spring; the spring is set in the support cylinder, one end is sleeved on the positioning post of the upper cover and is in clearance fit with it, and the other end is sleeved on the positioning post of the lower cover and is in clearance fit with it, in a compressed state.

[0012] As a further optimization of the closed stiffness nonlinear disc structure of the present invention, the flange ring of the upper cover and the support cylinder are fixed together by a number of circumferentially uniformly arranged bolts, and a sealing ring is provided between the flange ring of the upper cover and the support cylinder.

[0013] The flange ring of the lower cover and the support cylinder are fixed together by a number of circumferentially evenly arranged bolts, and a sealing ring is provided between the flange ring of the lower cover and the support cylinder.

[0014] As a further optimization of the closed stiffness nonlinear disc structure of the present invention, the spring is a metal spring or a rubber spring.

[0015] As a further optimization of the closed stiffness nonlinear disc structure of the present invention, the elastic bodies of the upper and lower covers are made of spring steel.

[0016] As a further optimization of the closed stiffness nonlinear disc structure of the present invention, the support cylinder is made of stainless steel.

[0017] Compared with the prior art, the present invention, employing the above technical solution, has the following technical effects:

[0018] 1. It has ultra-low frequency vibration isolation performance. By connecting a disc structure with negative stiffness characteristics and a positive stiffness elastic element in parallel, the total stiffness of the support system at the equilibrium position is in an extremely low range, achieving an ultra-low frequency vibration isolation effect that is difficult to achieve with traditional vibration isolation devices.

[0019] 2. The structure is compact and the space utilization rate is high. The disc-shaped mechanism can be used independently to directly bear the load, or it can be used in liquid or gaseous media without changing the space where the original external medium is located. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view of the structure of the present invention;

[0021] Figure 2 This is an exploded view of the structure of the present invention;

[0022] Figure 3 This is a structural schematic diagram of a vibration isolation system composed of four closed, stiffness-nonlinear disc structures.

[0023] Figure 4 A schematic diagram of the structure of the present invention filling an air spring;

[0024] Figure 5 This is a schematic diagram illustrating the change in displacement and deformation of the air spring of the present invention under a specific load as a function of internal air pressure.

[0025] In the diagram, 1-upper cover, 2-elastic element, 3-sealing groove, 4-ring support, 5-lower cover. Detailed Implementation

[0026] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings:

[0027] This invention can be implemented in many different forms and should not be considered limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully express the scope of the invention to those skilled in the art. In the drawings, components are enlarged for clarity.

[0028] like Figure 1 , Figure 2 As shown, the present invention discloses a closed stiffness nonlinear disc structure, comprising an upper cover, a lower cover, a support cylinder and a spring;

[0029] The upper and lower covers have the same structure and are disc-shaped. Each cover includes a base plate, an elastomer, and a flange ring. The base plate is a circular plate. The elastomer is a hollow frustum with open ends and is made of elastic material. Its smaller end is sealed and coaxially fixed to the base plate, and its larger end is sealed and coaxially fixed to the flange ring.

[0030] The support cylinder is a hollow cylinder with openings at both ends;

[0031] The upper and lower covers have openings facing each other, and their flange rings are respectively sealed and fixed to both ends of the support cylinder to form a sealed cavity;

[0032] The inner wall center of the substrate of the upper and lower covers is provided with a positioning post for cooperating with the spring; the spring is set in the support cylinder, one end is sleeved on the positioning post of the upper cover and is in clearance fit with it, and the other end is sleeved on the positioning post of the lower cover and is in clearance fit with it, in a compressed state.

[0033] The flange ring of the upper cover and the support cylinder are fixed together by several bolts evenly arranged in the circumference, and a sealing ring is provided between the flange ring of the upper cover and the support cylinder.

[0034] The flange ring of the lower cover and the support cylinder are fixed together by a number of circumferentially evenly arranged bolts, and a sealing ring is provided between the flange ring of the lower cover and the support cylinder.

[0035] The spring is a metal spring or a rubber spring, the elastic body of the upper and lower covers is made of spring steel, and the support cylinder is made of stainless steel.

[0036] The upper and lower covers undergo large-scale displacement deformation under load, and the distance between the base plate and the plane of the flange ring gradually decreases. When the two are on the same plane, they do not provide vertical support and the stiffness is zero. When the base plate crosses the plane of the flange ring, the disc cover exhibits a jumping phenomenon, and the base plate rapidly jumps and deforms to the other side of the flange ring, showing negative stiffness characteristics.

[0037] By changing parameters such as the thickness of the elastomer, the inner and outer diameters of the flange, the diameter of the base plate, and the distance between the base plate and the flange face, the upper and lower covers can achieve nonlinear stiffness design.

[0038] The base plates of the upper and lower covers are directly connected to the load application surface, directly bearing the external load to achieve the support function. The external load causes the disc-shaped structure to deform, exhibiting nonlinear stiffness characteristics, and achieving low stiffness support at the equilibrium position.

[0039] External media cannot penetrate the structure to enter the interior of the disc-shaped structure, which can create a pressure difference between the inside and outside, causing the structure to deform under pressure and exhibiting nonlinear stiffness characteristics. It is suitable for various external media environments such as gases and liquids.

[0040] This invention, as a vibration isolation support system for large structures, requires at least three or more sets of supports, each set consisting of one or more stacked disc-shaped structures. For example... Figure 3 The diagram shows a vibration isolation system composed of four closed, stiffness-nonlinear disc structures. The bottom of the isolators is fixedly connected to the foundation, and the top is connected to the structure or system requiring vibration isolation. A single support is formed by multiple disc structures connected in series, which can effectively improve the low-frequency dynamic range of the support system, that is, it has low-frequency characteristics over a larger displacement range. It is suitable for situations where the isolated system has a large vibration displacement. This embodiment shows the case where the disc structure is directly used as the support.

[0041] This invention serves as a mixing and filling component for liquid or gaseous media, acting within the media cavity. The disc-shaped structure is a closed design, creating an internal and external pressure difference with the liquid or gaseous media. Figure 4 The diagram shows an air spring filled with a closed disc structure. The air spring is subjected to a load, which generates air pressure higher than the internal pressure of the disc structure, thus creating a pressure difference between the inside and outside, causing the disc structure to deform. Figure 5 The air spring exhibits significant nonlinear characteristics in its displacement and deformation under specific loads, varying with internal air pressure. It reaches its lowest stiffness near the equilibrium position, effectively achieving ultra-low frequency characteristics in vibration isolation systems. In practical applications, when the air spring is under load, an external air pump pressurizes it, adjusting its internal pressure. This pressure acts on the disc-shaped structure, causing it to deform to an equilibrium state, thus achieving overall low stiffness and maximizing the performance of the support system.

[0042] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein.

[0043] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A closed-loop stiffness nonlinear disc structure, characterized in that, Includes an upper cover, a lower cover, a support cylinder, and a spring; The upper and lower covers have the same structure and are disc-shaped. Each cover includes a base plate, an elastomer, and a flange ring. The base plate is a circular plate. The elastomer is a hollow frustum with open ends and is made of elastic material. Its smaller end is sealed and coaxially fixed to the base plate, and its larger end is sealed and coaxially fixed to the flange ring. The support cylinder is a hollow cylinder with openings at both ends; The upper and lower covers have openings facing each other, and their flange rings are respectively sealed and fixed to both ends of the support cylinder to form a sealed cavity; The inner wall center of the substrate of the upper and lower covers is provided with a positioning post for cooperating with the spring; the spring is set in the support cylinder, one end is sleeved on the positioning post of the upper cover and is in clearance fit with it, and the other end is sleeved on the positioning post of the lower cover and is in clearance fit with it, in a compressed state.

2. The closed-loop stiffness nonlinear disc structure according to claim 1, characterized in that, The flange ring of the upper cover and the support cylinder are fixed together by several bolts evenly arranged in the circumference, and a sealing ring is provided between the flange ring of the upper cover and the support cylinder. The flange ring of the lower cover and the support cylinder are fixed together by a number of circumferentially evenly arranged bolts, and a sealing ring is provided between the flange ring of the lower cover and the support cylinder.

3. The closed-loop stiffness nonlinear disc structure according to claim 1, characterized in that, The spring can be a metal spring or a rubber spring.

4. The closed-loop stiffness nonlinear disc structure according to claim 1, characterized in that, The elastic bodies of the upper and lower covers are made of spring steel.

5. The closed-loop stiffness nonlinear disc structure according to claim 1, characterized in that, The support cylinder is made of stainless steel.

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