Low-frequency, broadband, multi-stage metamaterial radial vibration-damping bearing system

Abstract

The application provides a low-frequency broadband multistage metamaterial radial damping bearing system, which comprises a bearing seat and a bearing base connected with the bearing seat, and is characterized in that the bearing seat comprises a bushing, a local resonance type metamaterial damping layer and an outer shell arranged in sequence from inside to outside, and the bearing base comprises an array type metamaterial damping layer. The local resonance type acoustic metamaterial and the array type acoustic metamaterial are introduced into the bearing seat, the special properties of the metamaterial are combined, two metamaterial damping layers are arranged in the radial bearing system, the two metamaterial damping layers can inhibit bidirectional vibration transmission of self-excitation vibration of a rotor system and external excitation, and have excellent low-frequency broadband damping capacity.

Description

Technical Field

[0001] The present invention belongs to the field of vibration control of rotating mechanical systems, and in particular relates to a low-frequency, broadband, multi-stage metamaterial radial vibration-damping bearing system. Background Art

[0002] Rotating machinery often experiences misalignment due to factors such as unbalanced mass and assembly processes, causing frictional vibration in the rotor system. This is particularly true for underwater vehicle propulsion systems, where shafting frictional vibration not only reduces propulsion efficiency but also significantly impacts stealth capabilities. Traditional shock absorbers typically operate near their natural frequency, resulting in poor adjustability and weak low-frequency, broadband vibration damping capabilities. Furthermore, the installation space for ship propulsion systems is limited, requiring the precise design of traditional shock absorbers to accommodate the available space in the engine room, increasing manufacturing costs.

[0003] Acoustic metamaterials are artificially designed periodic or aperiodic geometric structures composed of two or more materials. They can achieve extraordinary properties such as acoustic focusing, acoustic stealth, acoustic imaging, acoustic waveguides, and acoustic black holes. Phononic crystals, whose unit size is much smaller than the controlled wavelength, offer advantages such as wide vibration reduction bandwidth and excellent vibration reduction capabilities, showing great promise in the field of low-frequency vibration reduction in ships. Research on key scientific and technological issues such as the suppression of low-frequency vibrations by acoustic metamaterials will not only extend the service life and reliability of ship shafting, but also play a significant role in promoting the development of acoustic stealth in ships. It also lays a key theoretical and technological foundation for the development of low-frequency vibration reduction metamaterials.

[0004] Therefore, the present invention utilizes the special properties of two acoustic metamaterials to propose a low-frequency, broadband, multi-stage metamaterial radial vibration-damping bearing system, which can suppress the bidirectional transmission of vibration between the self-excited vibration of the rotor system and external excitation. In addition, the band gap superposition characteristics of the acoustic metamaterial can enable the radial bearing system to have low-frequency, broadband vibration reduction capabilities. Summary of the Invention

[0005] The purpose of the present application is to provide a low-frequency, broadband, multi-stage metamaterial radial vibration-damping bearing system that can suppress the bidirectional transmission of vibrations between the self-excited vibration of the rotor system and external excitation.

[0006] This application is implemented as follows:

[0007] The present application provides a low-frequency, broadband, multi-stage metamaterial radial vibration-damping bearing system, comprising a bearing seat and a bearing base connected to the bearing seat, characterized in that: the bearing seat comprises a bushing, a local resonance metamaterial vibration-damping layer and an outer shell arranged in sequence from the inside to the outside, and the bearing base comprises an array metamaterial vibration-damping layer.

[0008] In some optional embodiments, the bearing seat is a split structure, divided into an upper part and a lower part.

[0009] In some optional embodiments, the local resonance metamaterial vibration reduction layer is composed of a plurality of monomer unit cell arrays, wherein the monomer unit cell includes a hexahedral matrix, a scatterer is provided in the matrix, and a cladding layer is provided around the scatterer.

[0010] In some optional embodiments, the scatterer is disposed in the middle of the substrate and is made of a rigid material, with the individual single unit cells being distributed in a uniform array.

[0011] In some optional embodiments, the outer diameters of the scatterers in each single cell are inconsistent, and the scatterers are arranged from small to large in the lateral direction according to their sizes to form a metamaterial vibration reduction layer.

[0012] In some optional embodiments, the lattice metamaterial vibration damping layer includes a plurality of unit cell structural units distributed in an array, wherein the cells are a body-centered cubic structure, the cells are of the same size, and are distributed in a multi-layer array to form a lattice metamaterial vibration damping layer.

[0013] In some optional embodiments, the lattice metamaterial vibration damping layer includes a plurality of single-cell structural units distributed in an array, wherein the cells are three-periodic minimal surface structures, the cells are of the same size, and are distributed in a multi-layer array to form a lattice metamaterial vibration damping layer.

[0014] In some optional embodiments, a bearing inner liner and a bearing outer liner are provided in the bushing.

[0015] In some optional embodiments, bearing end covers are provided on the housing at both ends corresponding to the bearing inner liner and the bearing outer liner, respectively, and the bearing end covers are fixed to the bearing seat by fasteners.

[0016] In some optional embodiments, the local resonance metamaterial vibration reduction layer surrounds the bushing to form an enclosing structure.

[0017] The bearing seat of the present invention introduces local resonance type acoustic metamaterials and lattice type acoustic metamaterials. Combined with the special properties of the metamaterials, two metamaterial vibration reduction layers are set in the radial bearing system, so that it can suppress the self-excited vibration of the rotor system and the bidirectional vibration transmission of external excitation, and has excellent low-frequency and broadband vibration reduction capabilities.

[0018] The beneficial effects of this application are:

[0019] 1) The radial bearing system of the present application mainly utilizes the local resonance characteristics of the local resonance type metamaterial and the advantages of light weight, strong impact resistance and good vibration and noise reduction ability of the lattice type metamaterial, respectively arranges a local resonance type metamaterial damping layer inside the bearing shell to reduce the low frequency vibration generated by the rotor system; arranges a lattice type metamaterial damping layer at the bottom of the bearing to support the radial bearing system and inhibit the bidirectional vibration transmission between the bearing seat and the external environment. The band gap superposition effect formed by the multi-stage metamaterial damping layer enables the radial bearing system to have the ability to control large wavelengths with small size. The array arrangement of multiple metamaterial units can widen the damping range to achieve the suppression of low frequency and wideband vibration of rotating machinery.

[0020] 2) The present application arranges and embeds the metamaterial artificial periodic structure in the radial bearing system to realize the integrated design of the support components and the damping device of the rotor system, which has the characteristics of compact structure and convenient installation, and can meet the needs of different installation environments.

[0021] 3) The two-stage metamaterial damping layer in the structure of the present application can be finely designed according to the vibration control requirements of the target, and the range of the damping frequency band can be adjusted by changing the cell structure parameters and array arrangement of the local resonance type metamaterial damping layer and the lattice type metamaterial damping layer, so that the radial bearing system has wide application and strong adaptability. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0023] Fig. 1(a) is a schematic diagram of the radial bearing system structure provided by the embodiment of the present application.

[0024] Fig. 1(b) is a top view of the radial bearing system provided by the embodiment of the present application.

[0025] Fig. 2(a) is a local resonance type metamaterial cell structure diagram provided by the embodiment of the present application.

[0026] Fig. 2(b) is a local resonance type metamaterial cell section view provided by the embodiment of the present application.

[0027] Fig. 3(a) to (c) are several local resonance type metamaterial array arrangement schematic diagrams provided by the embodiment of the present application.

[0028] Fig. 4(a) to (b) are several lattice type metamaterial damping layer structure schematic diagrams provided by the embodiment of the present application.

[0029] Figure 5 This is an eigenmode diagram of the local resonance metamaterial unit cell structure provided by an embodiment of the present invention.

[0030] Figure 6 Schematic diagram of the vibration reduction capabilities of several metamaterial structures provided by embodiments of the present invention.

[0031] 7( a ) to ( b ) are graphs showing the bandgap characteristics of the local resonance metamaterial under different structural parameters provided by an embodiment of the present invention.

[0032] 8(a) to (b) are schematic diagrams of two local resonance metamaterial arrays provided by embodiments of the present invention.

[0033] Figure 9 FIG4 is a comparison diagram of transmission losses of two local resonance metamaterial arrays provided in an embodiment of the present invention.

[0034] Among them: 1 shell; 2 local resonance metamaterial vibration reduction layer; 3 bushing; 4 bearing outer lining; 5 bearing inner lining; 6 lattice metamaterial vibration reduction layer; 7 bearing end cover; 8 bolt hole; 9 bolt hole; 10 bolt hole; 11 substrate; 12 coating layer; 13 scatterer. DETAILED DESCRIPTION

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0037] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0038] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of this application is typically placed when in use. These terms are intended only to facilitate the description of this application and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0039] Furthermore, terms such as "horizontal," "vertical," and "overhanging" do not necessarily imply that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0040] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0041] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0042] The features and performance of the present application are further described in detail below with reference to the embodiments.

[0043] Example 1:

[0044] Referring to Figures 1(a) and 1(b), the low-frequency, broadband, multi-stage metamaterial radial vibration damping bearing system provided in this application includes a bearing seat and a bearing base connected to the bearing seat. The bearing seat includes a bushing 3, a local resonance metamaterial vibration damping layer 4, and a shell 1, arranged in sequence from the inside to the outside. The bushing 3 is an annular cylindrical sleeve that is mounted on the outside of the bearing outer liner 4 and the bearing inner liner 5. The local resonance metamaterial vibration damping layer 4 surrounds the bushing 3 to form an enclosing structure. The bearing base includes a matrix metamaterial vibration damping layer 6. Four bolt holes 9 are provided at positions corresponding to the lattice metamaterial vibration damping layer 6 and the shell 1 to secure the radial bearing system to the mounting plane. The shell 1, the local resonance metamaterial vibration damping layer 2, and the bushing 3 are upper and lower split structures, connected by four bolt holes 10 at the left and right ends of the shell 1. The bearing end caps 7 are arranged at both ends of the bearing and secured to the bearing seat via eight bolt holes 8.

[0045] 2(a) and 2(b), the local resonance type material monomer unit cell of the present invention includes a matrix 11 with a polyhedral structure. The polyhedral structure can be a tetrahedron (triangle), a hexahedron (square or quad), or an octahedron (triangles stacked in an array to form a large prism), etc. This embodiment is described using a hexahedron as an example. A scatterer 13 made of a rigid material is provided in the middle position of the matrix, and a coating layer 12 is provided around the scatterer. The monomer unit cell is manufactured using 3D printing technology. First, a high-elasticity, high-damping coating layer is evenly coated on the surface of the rigid scatterer, and the scatterer is placed in a mold and filled into the matrix.

[0046] 3( a ), the local resonance metamaterial vibration reduction layer of the present invention is composed of a plurality of monomer unit cells that are evenly distributed in an array, and the outer diameters of the scatterers in each unit cell are consistent.

[0047] 4( a ), the lattice-type metamaterial vibration damping layer includes a plurality of single-cell structural units distributed in an array, wherein the cells are of a common body-centered cubic structure (BCC), the cells are of the same size, and are distributed in a multi-layer array to form a lattice-type metamaterial vibration damping layer.

[0048] Reference Figure 5 As shown, under the excitation of elastic waves with frequencies within the band gap, the cladding and scatterer of the local resonance metamaterial unit cell resonate, causing deformation and displacement, and interacting with the traveling waves of elastic wavelengths in the matrix, thereby suppressing the transmission of elastic waves in the metamaterial and reflecting the local resonance characteristics.

[0049] Reference Figure 6As shown, a local resonant structure and a lattice metamaterial were arrayed to verify their vibration transmission. During the transmission of elastic waves at different frequencies, the local resonant structure and the lattice metamaterial each produced different band gaps. When the two structures were arrayed together, vibrations within both band gap frequencies were attenuated, demonstrating the superposition effect of band gaps.

[0050] The radial bearing system of the present invention primarily utilizes the localized resonance characteristics and bandgap superposition effect of metamaterials, enabling it to control large wavelengths with a small size. The array arrangement of multiple metamaterial units can broaden the vibration reduction range, thereby achieving the suppression of low-frequency, broadband vibrations in rotating machinery.

[0051] The present invention integrates the rotor system's support components and vibration damping equipment by arranging and embedding artificial periodic metamaterial structures into a radial bearing system. This device features a compact structure and easy installation. The two-stage metamaterial damping layer in the present invention's structure can be finely designed to meet the target vibration control requirements. The damping frequency range can be adjusted by varying the unit cell structure parameters and array arrangement of the local resonance metamaterial damping layer and the lattice metamaterial damping layer, thus enabling the radial bearing system to have a wide range of applications and strong adaptability. Taking the local resonance metamaterial as an example, its matrix is ​​made of sarlon, the cladding layer is made of silicone rubber, and the scatterer is made of structural steel. The material parameters of each component are shown in Table 1. In terms of adjusting the vibration reduction frequency band by using the unit cell structure parameters, under the condition that the substrate size remains unchanged, the coating thickness S of the material and the scatterer radius R2 are changed respectively, as shown in Figure 7. It can be seen that the starting frequency, cutoff frequency and bandwidth y of the material's band gap are all changed, among which the scatterer has a greater impact on the material's band gap. Under this working condition, the relationship between the bandwidth of the material and the coating thickness is shown in formula (1), and the relationship between it (bandwidth) and the scatterer radius is shown in formula (2). In terms of adjusting the vibration reduction frequency band by array arrangement, three different unit cell structures are designed according to the scatterer radius to form two array modes, as shown in Figure 8. The transmission loss of the two array structures is compared, as shown in Figure 8. Figure 9 It can be seen that different arraying methods significantly affect the material's transmission loss. Relatively speaking, the ABC structure has a stronger vibration reduction effect and a wider vibration reduction frequency band. Overall, by designing the structural parameters and arraying methods of the unit cells, the vibration reduction frequency band and vibration reduction capability of the metamaterial can be effectively changed. By combining multi-parameter optimization algorithms, such as the response surface optimization method, the characteristic dimensions of the metamaterial unit cell structure are selected as optimization parameters, and the vibration control requirements are used as the optimization target, to carry out a refined design of the unit cell structure.

[0052] y=965.1e -s / 1.32 +227.99 (1)

[0053]

[0054] Table 1 Material parameters

[0055]

[0056]

[0057] Example 2:

[0058] As shown in Figures 3(b) and 4(b), this embodiment has essentially the same structure as the first embodiment, with the following differences: 1. The unit cell structure of the localized resonant metamaterial vibration damping layer 2 is as follows: the outer diameters of the scatterers in each unit cell are inconsistent, and a layer of high-damping coating material is applied to the outer diameters. This coating is then filled into the center of the substrate to form a hexahedral unit cell, which is arranged in increasing order of scatterer size in the transverse direction to form the metamaterial vibration damping layer 2. 2. The cells of the lattice-type metamaterial vibration damping layer are three-periodic minimal surface structures (IWPs), with cells of uniform size and arranged in a multi-layer array to form the lattice-type metamaterial vibration damping layer.

[0059] Example 3:

[0060] 3( c ), the structure of this embodiment is substantially the same as that of the first embodiment, except that the unit cell structure of the localized resonant metamaterial vibration damping layer 2 is as follows: the outer diameters of the scatterers in each unit cell are inconsistent, and a layer of high-damping coating material is coated on the outer diameter, which is then filled into the middle of the substrate to form a hexahedral unit cell. The scatterers are arranged in a lateral direction from large to small according to their size to form the metamaterial vibration damping layer 2.

[0061] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. For example, the unit cell structures of the three types of local resonance metamaterial vibration damping layers in the present application can be arbitrarily combined with the cell structures of the two types of lattice metamaterial vibration damping layers to form different vibration damping bearing systems, and the specific design depends on the actual working conditions. That is, the two-stage metamaterial vibration damping layer in the structure of the present invention can be finely designed according to the vibration control requirements of the target, and the range of the vibration damping frequency band can be adjusted by changing the unit cell structure parameters and array arrangement of the local resonance metamaterial vibration damping layer and the lattice metamaterial vibration damping layer, so that the radial bearing system has a wide range of applications and strong adaptability. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application to be protected, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

Claims

1. A low-frequency, broadband, multi-stage metamaterial radial vibration damping bearing system, comprising a bearing seat and a bearing base connected to the bearing seat, characterized in that: The bearing seat includes a bushing, a local resonance metamaterial vibration damping layer and a shell arranged in sequence from the inside to the outside. The bearing base includes a lattice metamaterial vibration damping layer. The local resonance metamaterial vibration damping layer is composed of a plurality of monomer unit cell arrays. The monomer unit cell includes a polyhedral structure matrix, a scatterer is provided in the matrix, and a coating layer is provided around the scatterer. The outer diameters of the scatterers in each single unit cell are inconsistent. According to the size of the scatterers, they are arranged from small to large in the transverse direction to form a metamaterial vibration damping layer.

2. The low-frequency, broadband, multi-stage metamaterial radial vibration damping bearing system according to claim 1, characterized in that: The bearing seat is a split structure, divided into two parts, an upper part and a lower part.

3. The low-frequency, broadband, multi-stage metamaterial radial vibration damping bearing system according to claim 1, characterized in that: The scatterer is arranged in the middle of the base, is made of a rigid material, and each single unit cell is distributed in a uniform array.

4. The low-frequency, broadband, multi-stage metamaterial radial vibration damping bearing system according to claim 1 or 2, characterized in that: The lattice metamaterial vibration damping layer includes a plurality of single-cell structural units distributed in an array, wherein the cells are a body-centered cubic structure, the cells are of the same size, and are distributed in a multi-layer array to form a lattice metamaterial vibration damping layer.

5. The low-frequency, broadband, multi-stage metamaterial radial vibration damping bearing system according to claim 1 or 2, characterized in that: The lattice metamaterial vibration damping layer includes a plurality of single-cell structural units distributed in an array, wherein the cells are three-periodic minimal surface structures, the cells are of the same size, and are distributed in a multi-layer array to form a lattice metamaterial vibration damping layer.

6. The low-frequency, broadband, multi-stage metamaterial radial vibration damping bearing system according to claim 4, characterized in that: A bearing inner liner and a bearing outer liner are arranged in the bushing.

7. The low-frequency, broadband, multi-stage metamaterial radial vibration damping bearing system according to claim 6, characterized in that: Bearing end covers are respectively provided on the housing at both ends corresponding to the bearing inner liner and the bearing outer liner, and the bearing end covers are fixed on the bearing seat by fasteners.

8. The low-frequency, broadband, multi-stage metamaterial radial vibration damping bearing system according to claim 1 or 2, characterized in that: The local resonance metamaterial vibration reduction layer surrounds the bushing to form an enclosing structure.

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