Low-frequency vibration isolation rotating shaft supporting structure and construction method

Abstract

The invention discloses a low-frequency vibration isolation rotating shaft supporting structure and a construction method, and the supporting structure comprises a main body frame which comprises an inner ring, an outer ring and a partition plate, the inner ring and the outer ring are respectively used for connecting an excitation end and a response end, the partition plate is arranged between the inner ring and the outer ring, and the partition plate, the inner ring and the outer ring are connected to form a plurality of spaces; and a cell disposed in each space, the cell including a cantilever beam and a mass block. The supporting structure is based on a local resonance mechanism, the cantilever beam-mass block honeycomb cells are used, the obvious vibration isolation characteristic is achieved within the target frequency range, the structure is relatively simple, a complex manufacturing process and high material cost are not needed, and the machining difficulty and cost are reduced.

Description

Technical Field

[0001] This application belongs to the technical field of automatic control, and particularly relates to a low-frequency vibration isolation rotating shaft support structure and a construction method thereof. Background Art

[0002] As an important part of the rotor system, the performance of the support structure directly affects the service life, vibration and noise of the housing fixedly connected thereto. With the improvement of living standards, mechanical equipment is developing towards the direction of low noise, and the vibration of the rotor system is one of the important noise sources of mechanical equipment.

[0003] For the vibration isolation requirement of mechanical equipment, the design of the support structure can combine the local resonance principle and the Bragg diffraction principle. Among them, the structural design combining the local resonance principle is relatively complex, the processing cost is relatively high, and the space utilization rate is relatively low; the structural support stiffness of the combination of the Bragg diffraction principle is low, the vibration isolation frequency band is high, and the load-bearing capacity and vibration isolation ability are poor. Summary of the Invention

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

[0005] This application provides a technical solution:

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

[0007] A main body frame, including an inner ring, an outer ring and a partition board. The inner ring and the outer ring are coaxially arranged. The inner ring and the outer ring are respectively used to connect the excitation end and the response end. The partition board is arranged between the inner ring and the outer ring. After the partition board is connected to the inner ring and the outer ring, a plurality of spaces are formed;

[0008] Unit cells, arranged in each space. Each unit cell includes a cantilever beam and a mass block. One end of the cantilever beam is connected to the partition board, and the mass block is connected to the other end of the cantilever beam.

[0009] This application also provides a construction method of a low-frequency vibration isolation rotating shaft support structure. The method includes the following steps:

[0010] Construct a three-dimensional model of a solid support structure: According to the geometric dimensions of the rotating shaft, use three-dimensional modeling software to construct a three-dimensional model of the solid support structure;

[0011] Establish a three-dimensional model of the main body frame: Under the requirement of meeting the support stiffness, dig holes in the solid support structure to establish a three-dimensional model of the main body frame;

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

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

[0014] The beneficial effects of this application are as follows: It not only has strong machinability, low processing cost, simple structure, but also has good adjustability of the vibration isolation frequency band, which can effectively reduce the difficulty of design and production. Description of the Drawings

[0015] Figure 1 It is a schematic diagram of the main frame structure of the support structure provided by this application.

[0016] Figure 2 It is a schematic diagram of the structure of the unit cells provided by this application.

[0017] Figure 3 It is a schematic diagram of the overall structure of the support structure provided by the embodiment of this application.

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

[0019] Figure 5 It is a flowchart of a method for constructing a low-frequency vibration isolation rotating shaft support structure in this application.

[0020] Figure 6 It is a vibration transfer characteristic curve diagram of this application.

[0021] Explanation of the reference numerals in the drawings: 1. Cantilever beam; 2. Mass block; 3. Main frame. Detailed Embodiments

[0022] The technical solutions in the embodiments of this application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts shall fall within the protection scope of this application.

[0023] Refer to Figure 1-4 , this application provides a low-frequency vibration isolation rotating shaft support structure, which includes two parts: a main frame 3 and unit cells.

[0024] The main frame 3 includes an inner ring, an outer ring, and partition plates. The inner ring and the outer ring are respectively used to connect the excitation end and the response end. The excitation end is the rotating shaft, and the response end is the housing. The inner ring and the outer ring are coaxially arranged, and the partition plates are connected between the inner ring and the outer ring. There are multiple groups of partition plates in the embodiments of the present application. Each group of partition plates includes two parallel partition plates and a partition plate connected between the parallel partition plates, forming an H-shaped structure. After each H-shaped structure of partition plates is connected to the inner ring and the outer ring, two similar rectangular spaces will be formed, and each space is used to install a cell.

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

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

[0027] S1. Construct a three-dimensional model of a solid support structure: According to the geometric dimensions of the rotating shaft, use three-dimensional modeling software to construct a three-dimensional model of the solid support structure.

[0028] S2: Establish a three-dimensional model of the main frame: Under the requirement of meeting the support stiffness, dig holes in the solid support structure to establish a three-dimensional model of the main frame 3 as Figure 1 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 range. According to Figure 3 shown, combine the three-dimensional model of the cells with the three-dimensional model of the main frame 3 to obtain a preliminary support structure.

[0030] S4: Calculate and adjust: 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 range. If not, adjust the size parameters of the cells, recalculate the frequency response until the vibration isolation frequency band coincides with the target frequency band range. Because the mechanical properties are different after the curvature of the cells changes, the size of the cells needs to be adjusted each time, and the frequency response of the support structure is computer-simulated each time the size is adjusted.

[0031] The present application provides a low-frequency vibration isolation rotating shaft support structure. Based on the local resonance mechanism, this structure uses a cantilever beam-mass block honeycomb unit cell and has 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 band range can be adjusted. According to Bloch's theorem, the vibration isolation frequency bands of the unit cells with different parameters can be obtained. The low-frequency rotating shaft support structure of the present application not only has obvious vibration isolation characteristics within the target frequency range, but also has a relatively simple structure, does not require complex manufacturing processes and high material costs, and reduces the processing difficulty and cost.

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

[0033] To verify the effectiveness of the construction method of the low-frequency vibration isolation rotating shaft support structure of the present application, taking the vibration isolation frequency of 180 Hz as an example, a support structure based on the local resonance mechanism was established. Among them, as Figure 2 shown, the size parameters of the cantilever beam 1 and the mass block 2 in the unit cell are shown in Table 1, and the material parameters are shown in Table 2. In Table 1, a 1 is the external height of the space formed by the H-shaped partition board, a 2 is the external width of the space, b 1 is the internal height of the space, b 2 is the internal width of the space, c 1 is the width of the mass block 2, c 2 is the height of the mass block 2, d is the distance between the center of the mass block 2 and the partition board, x is the horizontal distance between the center of the mass block 2 and the bending point of the cantilever beam 1, y is the vertical distance between the center of the mass block 2 and the bending point of the cantilever beam 1, and z is the thickness of the bending point of the cantilever beam 1. Based on Bloch's theorem, the dispersion curve of the unit cell can be obtained, and then the band gaps in different directions can be obtained. Its band gap is 119 - 127 Hz. The reason why the band gap does not coincide with the vibration isolation frequency is that the unit cells in the support structure are not arranged in the arrangement manner in Bloch's theorem, and the frequency range in which the support structure has a vibration damping effect does not necessarily coincide completely with the band gap.

[0034] Table 1 Geometric parameters of the unit cell

[0035] Parameter Name Value (mm) <![CDATA[a 1 > 40 <![CDATA[a 2 > 40 <![CDATA[b 1 > 36 <![CDATA[b 2 > 6 <![CDATA[c 1 > 12 <![CDATA[c 2 > 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] At Figure 4In the support structure, a simple harmonic excitation is given to the excitation end, the displacements of the excitation end and the response end are calculated by software, and the vibration transfer characteristic function of the support structure is obtained by using the transfer characteristic function \(T = 20\lg(a 2 / a 1 ). The vibration transfer characteristic curve of the support structure is as shown in Figure 6 . At 180 Hz, its vibration transfer ratio \(T\) is about -25 dB, that is, the vibration displacement of the response end is about 5% of that of the excitation end.

[0039] At the same time, the support structure can be manufactured by traditional processes such as wire cutting, which can greatly reduce the production cost; the design of the thickness, length, etc. of the cantilever beam 1 is simple, which greatly improves the production efficiency.

[0040] It can be seen from the above results that the 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 introduced in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of this application. After those skilled in the art have read the above content, various modifications and substitutions to this application will be obvious. Therefore, the protection scope of this application should be defined by the appended claims.

Claims

1. A low-frequency vibration isolation shaft support structure, characterized in that: The support structure comprises: A main frame (3) comprises an inner ring, an outer ring and a partition, wherein the inner ring and the outer ring are coaxially arranged, the inner ring and the outer ring are respectively used to connect an excitation end and a response end, the partition is arranged between the inner ring and the outer ring, and the partition, the inner ring and the outer ring are connected to form a plurality of spaces; A cell is arranged in each of the spaces, the cell comprising a cantilever beam (1) and a mass block (2), one end of the cantilever beam (1) is connected to the partition plate, and the mass block (2) is connected to the other end of the cantilever beam (1).

2. The low-frequency vibration isolation shaft support structure according to claim 1, characterized in that: The partition includes two parallel partitions and a partition connected between the parallel partitions.

3. The low-frequency vibration isolation shaft support structure according to claim 1, characterized in that: The cantilever beam (1) is a V-shaped structure.

4. The low-frequency vibration isolation shaft support structure according to claim 1, characterized in that: The cantilever beam (1) and the mass block (2) are both made of resin.

5. A method for constructing a low-frequency vibration isolation shaft support structure, the method being applied to the low-frequency vibration isolation shaft support structure according to any one of claims 1 to 4, characterized in that: The steps include: Constructing a 3D model of a solid support structure: Based on the geometric dimensions of the shaft, a 3D model of the solid support structure is constructed using 3D modeling software; Establishing a three-dimensional model of the main frame: digging holes in the solid support structure while meeting the requirements of support stiffness, and establishing a three-dimensional model of the main frame (3); Establishing and combining cells: establishing a three-dimensional model of cells with the vibration isolation frequency band as the target frequency band range, combining the three-dimensional model of the cells with the three-dimensional model of the main frame (3) to obtain a preliminary support structure; Calculation and adjustment: Calculate the frequency response of the support structure to determine whether the vibration isolation frequency band of the frequency response coincides with the target frequency band range. If not, adjust the size parameters of the cell and recalculate the frequency response until the vibration isolation frequency band coincides with the target frequency band range.

6. The method for constructing a low-frequency vibration isolation shaft support structure according to claim 5, characterized in that: The frequency response is calculated by computer simulation.

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