A low-frequency vibration isolation shaft support structure and its construction method

Abstract

The application discloses a low-frequency vibration isolation rotating shaft support structure and a construction method. The support structure comprises a main frame, an inner ring, an outer ring and a partition plate. The inner ring and the outer ring are used for connecting an excitation end and a response end, respectively. The partition plate is arranged between the inner ring and the outer ring. The partition plate, the inner ring and the outer ring are connected to form a plurality of spaces. A cell is arranged in each space. The cell comprises a cantilever beam and a mass block. The support structure is based on a local resonance mechanism. The use of the cantilever beam-mass block honeycomb cell not only has obvious vibration isolation characteristics in a target frequency range, but also has a relatively simple structure, does not need complex manufacturing processes and high material costs, and reduces processing difficulty and cost.

Description

Technical Field

[0001] This application belongs to the field of automation control technology, specifically relating to a low-frequency vibration isolation shaft support structure and its construction method. Background Technology

[0002] As a crucial component of the rotor system, the performance of the support structure directly affects the lifespan and vibration noise of the housing it is rigidly connected to. With rising living standards, mechanical equipment is evolving towards lower noise levels, and rotor system vibration is one of the significant noise sources in mechanical equipment.

[0003] To address the vibration isolation requirements of mechanical equipment, the design of the support structure can incorporate the principles of local resonance and Bragg diffraction. However, designs incorporating the local resonance principle are relatively complex, have higher manufacturing costs, and lower space utilization. Structures incorporating the Bragg diffraction principle have lower support stiffness, higher isolation frequencies, and poorer load-bearing and vibration isolation capabilities. Summary of the Invention

[0004] The purpose of this application is to provide a low-frequency vibration isolation shaft support structure and its construction method, which solves the problems of low support stiffness, high vibration isolation frequency band, and poor load-bearing capacity and vibration isolation capacity of the existing shaft support structure.

[0005] This application provides a technical solution:

[0006] A low-frequency vibration isolation shaft support structure, the support structure comprising:

[0007] The main frame includes an inner ring, an outer ring, and a partition. The inner and outer rings are coaxially arranged and are used to connect the excitation end and the response end, respectively. The partition is arranged between the inner and outer rings. After the partition, the inner ring, and the outer ring are connected, multiple spaces are formed.

[0008] A cell is set in each space. A cell consists of a cantilever beam and a mass block. One end of the cantilever beam is connected to a partition, and the mass block is connected to the other end of the cantilever beam.

[0009] This application also provides a method for constructing a low-frequency vibration isolation shaft support structure, the method comprising the following steps:

[0010] Constructing a 3D model of the solid support structure: Based on the geometric dimensions of the pivot, construct a 3D model of the solid support structure using 3D modeling software;

[0011] Establish a three-dimensional model of the main frame: Under the condition of meeting the requirements of support stiffness, holes are drilled in the solid support structure to establish a three-dimensional model of the main frame;

[0012] Establish and combine cells: Establish a three-dimensional model of cells with the vibration isolation frequency band as the target frequency band, and combine the three-dimensional model of cells with the three-dimensional model of the main frame to obtain the preliminary support structure;

[0013] Calculation and Adjustment: Calculate the frequency response of the support structure and determine whether the vibration isolation frequency band of the frequency response coincides with the target frequency band. If they do not coincide, adjust the size parameters of the cells and recalculate the frequency response until the vibration isolation frequency band coincides with the target frequency band.

[0014] The beneficial effects of this application are: it is not only highly manufacturable and has low processing costs and a simple structure, but also has good adjustability of the vibration isolation frequency band, which can effectively reduce the difficulty of design and production. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the main frame structure of the supporting structure provided in this application.

[0016] Figure 2 This is a schematic diagram of the cell structure provided in this application.

[0017] Figure 3 This is a schematic diagram of the overall structure of the support structure provided in the embodiments of this application.

[0018] Figure 4 This is a model diagram of the support structure with a vibration isolation frequency of 180Hz as described in this application.

[0019] Figure 5 This is a flowchart of a method for constructing a low-frequency vibration isolation shaft support structure according to this application.

[0020] Figure 6 This is a graph showing the vibration transmission characteristics of this application.

[0021] The following are the symbols and their meanings: 1. Cantilever beam; 2. Mass block; 3. Main frame. Detailed Implementation

[0022] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0023] Reference Figure 1-4 This application provides a low-frequency vibration isolation shaft support structure, which includes a main frame 3 and two parts: a cell.

[0024] The main frame 3 includes an inner ring, an outer ring, and a partition. The inner and outer rings are used to connect the excitation end and the response end, respectively. The excitation end is the rotating shaft, and the response end is the housing. The inner and outer rings are coaxially arranged, and the partition connects the inner and outer rings. In this embodiment, there are multiple sets of partitions. Each set of partitions includes two parallel partitions and a partition connecting the parallel partitions, forming an H-shaped structure. After each H-shaped partition is connected to the inner and outer rings, it will form two rectangular spaces, each of which is used to install a cell.

[0025] The cell comprises a cantilever beam 1 and a mass block 2. The cantilever beam 1 has a V-shaped structure and therefore a bending point. One end of the cantilever beam 1 is connected to a partition, and the other end is connected to the mass block 2. When cells are installed in each space, the support structure of this application is formed.

[0026] like Figure 5 As shown, this application also provides a method for constructing a low-frequency vibration isolation shaft support structure, including the following steps:

[0027] S1. Construct a three-dimensional model of the solid support structure: Based on the geometric dimensions of the pivot, construct a three-dimensional model of the solid support structure using 3D modeling software.

[0028] S2: Establish a 3D model of the main frame: Under the condition of meeting the requirements of support stiffness, drill holes in the solid support structure and establish a model as follows. Figure 1 The three-dimensional model of the main frame 3 shown.

[0029] S3: Establish and combine cells: Establish a three-dimensional model of cells with the vibration isolation frequency band as the target frequency band, based on... Figure 3 As shown, the three-dimensional model of the cell is combined with the three-dimensional model of the main frame 3 to obtain the preliminary support structure.

[0030] S4: Calculation and Adjustment: Calculate the frequency response of the support structure to determine if the vibration isolation frequency band coincides with the target frequency band. If they do not coincide, adjust the cell size parameters and recalculate the frequency response until the vibration isolation frequency band coincides with the target frequency band. Because the mechanical properties differ after the curvature of the cells changes, the cell size needs to be adjusted each time. After each size adjustment, a computer simulation of the frequency response of the support structure is performed.

[0031] This application provides a low-frequency vibration-isolation pivot support structure. Based on the local resonance mechanism, this structure utilizes a cantilever beam-mass block honeycomb cell structure to achieve vibration isolation characteristics in the low-frequency range. By adjusting the geometric parameters of the cantilever beam and the mass block, the vibration isolation frequency range can be adjusted. According to Bloch's theorem, the vibration isolation frequency bands of the cells under different parameters can be obtained. This low-frequency pivot support structure not only exhibits significant vibration isolation characteristics within the target frequency range but also boasts a relatively simple structure, eliminating the need for complex manufacturing processes and high material costs, thus reducing processing difficulty and cost.

[0032] The low-frequency vibration isolation shaft support structure of this application is based on the local resonance mechanism and a simple structural form, making its fabrication process relatively simple and easy for engineers to optimize. At the same time, the honeycomb cell structure can achieve good vibration isolation within a small space, improving space utilization and making it suitable for equipment with limited space.

[0033] To verify the effectiveness of the low-frequency vibration isolation shaft support structure construction method of this application, a support structure based on the local resonance mechanism was established, taking a vibration isolation frequency of 180Hz as an example. For example, Figure 2 As shown in Table 1, the dimensional parameters of the cantilever beam 1 and mass block 2 in the cell are shown in Table 2, and the material parameters are shown in Table 1. In Table 1, a1 is the external height of the space formed by the H-shaped partition, a2 is the external width of the space, b1 is the internal height of the space, b2 is the internal width of the space, c1 is the width of mass block 2, c2 is the height of mass block 2, d is the distance between the center of mass block 2 and the partition, x is the horizontal distance between the center of mass block 2 and the bending point of cantilever beam 1, y is the vertical distance between the center of mass block 2 and the bending point of cantilever beam 1, and z is the thickness of the bending point of cantilever beam 1. Based on Bloch's theorem, the dispersion curve of the cell can be obtained, and thus its band gap in different directions can be obtained. Its band gap is 119-127Hz. The reason why the band gap does not coincide with the vibration isolation frequency is that the cells in the support structure are not arranged according to the arrangement in Bloch's theorem, and the frequency range in which the support structure has a vibration reduction effect does not necessarily coincide completely with the band gap.

[0034] Table 1. Geometric parameters of the cell

[0035] Parameter name Value (mm) <![CDATA[a1]]> 40 <![CDATA[a2]]> 40 <![CDATA[b1]]> 36 <![CDATA[b2]]> 6 <![CDATA[c1]]> 12 <![CDATA[c2]]> 16 d 24 x 15 y 11 z 3

[0036] Table 2 Material Parameters

[0037] Material <![CDATA[Density (kg / m 3 )]]> Elastic modulus (Pa) Poisson's ratio resin 1250 2.65e9 0.41

[0038] exist Figure 4 In the support structure, a simple harmonic excitation is applied to the excitation end. The displacements of the excitation and response ends are calculated using software, and the vibration transmission characteristics of the support structure are obtained using the transmission characteristic function T = 20lg(a2 / a1). The vibration transmission characteristic curve of the support structure is shown below. Figure 6 As shown, at 180Hz, its vibration transmissibility T is approximately -25dB, meaning that the vibration displacement at the response end is approximately 5% of that at the excitation end.

[0039] Meanwhile, the support structure can be manufactured using traditional processes such as wire cutting, which can significantly reduce production costs; the thickness and length of the cantilever beam 1 are designed simply, which greatly improves production efficiency.

[0040] The results above show that this support structure has significant advantages in the low-frequency range and has application value for industrial production.

[0041] Although the content of this application has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as a limitation of this application. Various modifications and substitutions to this application will be apparent to those skilled in the art after reading the above content. Therefore, the scope of protection of this application should be defined by the appended claims.

Claims

1. A low-frequency vibration isolation rotating shaft support structure characterized by comprising: The support structure comprises: a main frame (3) comprising an inner ring, an outer ring and a partition plate, the inner ring and the outer ring being coaxially arranged, the inner ring and the outer ring being used for connecting an excitation end and a response end respectively, the partition plate being arranged between the inner ring and the outer ring, the partition plate, the inner ring and the outer ring forming a plurality of spaces after being connected, the partition plate comprising two parallel partition plates and a partition plate connected between the parallel partition plates; a cell arranged in each of the spaces, the cell comprising a cantilever beam (1) and a mass block (2), the cantilever beam (1) being in a V-shaped structure, the cantilever beam (1) and the mass block (2) both being made of resin, one end of the cantilever beam (1) being connected to the partition plate, the mass block (2) being connected to the other end of the cantilever beam (1), the size parameters of the cell being adjusted so that the vibration isolation frequency band of the frequency response of the support structure coincides with a target frequency range.

2. A method of constructing a low-frequency vibration-isolated rotating shaft support structure, the method being applied to the low-frequency vibration-isolated rotating shaft support structure according to claim 1, characterized by, The method comprises the following steps: constructing a three-dimensional model of a solid support structure: constructing a three-dimensional model of a solid support structure according to the geometric dimensions of the shaft by using a three-dimensional modeling software; establishing a three-dimensional model of a main frame: under the requirement of support stiffness, the solid support structure is excavated to establish a three-dimensional model of a main frame (3); establishing and combining a cell: a three-dimensional model of a cell with a vibration isolation frequency band as a target frequency range is established, the three-dimensional model of the cell is combined with the three-dimensional model of the main frame (3) to obtain a preliminary support structure; calculation and adjustment: the frequency response of the support structure is calculated to determine whether the vibration isolation frequency band of the frequency response coincides with the target frequency range, if not, the size parameters of the cell are adjusted, the frequency response is recalculated until the vibration isolation frequency band coincides with the target frequency range.

3. The construction method of a low-frequency vibration isolation rotating shaft support structure according to claim 2, characterized in that, The frequency response is calculated in a computer simulation manner.

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