Shafting broadband damping device based on metal rubber

Abstract

In order to solve the problems that a traditional damping device is narrow in frequency band and poor in environmental adaptability, a plurality of unit cells are periodically arranged from left to right to form a periodic structure, and each unit cell comprises an inner lining, first metal rubber, an outer lining and second metal rubber. The first metal rubber and the second metal rubber are symmetrically arranged and located in the outer lining, and at the end of the shafting structure, the inner lining is degraded into an end lining. According to the invention, the metal rubber and the bushing are periodically arranged, so that the metal rubber shaft system structure forms a periodic structure, the periodic structure has a band gap characteristic, and a vibration load is transmitted into a load transmission path from one end of the metal rubber shaft system structure; through friction energy dissipation and vibration reduction between the metal wires of the metal rubber and vibration reduction of a vibration band gap formed by the periodic structure, an excitation load at a specific frequency can form a forbidden band, so that vibration reduction is achieved, and the frequency range of vibration reduction is widened.

Description

Technical Field

[0001] The present invention relates to the technical field of vibration reduction of a support rod shaft system structure, and in particular to a wide-band vibration reduction device of a shaft system based on metal rubber. Background Art

[0002] The simple structure and axial load-bearing behavior of the strut shaft system allow it to provide both support and vibration reduction, resulting in a wide range of applications in fields such as aviation, aerospace, and mechanical engineering. Examples include wind tunnel testing, supporting solar panels in the form of space trusses, and boring bars for deep hole machining.

[0003] Strut shafting systems are often used in scenarios where harmful vibration excitation occurs at one end, while sensitive components are located at the other end. Therefore, strut shafting systems are designed to reduce vibration. For example, in a helicopter, the impact excitation generated by gear meshing causes structural vibration, which is further transmitted to the fuselage through the connecting struts between the reducer and the fuselage, thereby inducing cabin noise.

[0004] Metal rubber is a porous metal material formed by braiding, winding, and stamping metal wires. It is called metal rubber because of its rubber-like elasticity and damping properties. When subjected to vibration loads, friction between the wires dissipates energy, thereby achieving vibration reduction. Metal rubber is also highly stable and can function properly in extreme environmental conditions such as vacuum, high and low temperatures, salt corrosion, and radiation. Therefore, it is often used for vibration isolation and reduction in extreme environments such as aerospace, shipping, and deep-sea environments. A periodic structure has units arranged periodically in space, which can produce band gap characteristics within a specific frequency band, thereby achieving vibration reduction.

[0005] In summary, conventional strut structures are prone to transmitting vibrations to sensitive components under vibration excitation, resulting in cabin noise. Improving the vibration reduction effectiveness of strut structures is a critical issue that needs to be addressed. Therefore, designing a device that combines the frictional energy dissipation of metals like rubber with the bandgap properties of periodic structures to broaden the vibration reduction frequency band and enhance the vibration reduction effect is of great significance. Summary of the Invention

[0006] In response to the problems of narrow frequency band and poor environmental adaptability of traditional vibration damping devices, the present invention proposes a wide-band vibration damping device for shafting based on metal rubber, which combines the energy dissipation of metal rubber with the band gap characteristics of periodic structure to improve the vibration reduction effect.

[0007] The technical solution adopted by the present invention to solve the above problems is: A wide-band vibration damping device for shafting based on metal rubber. The device comprises multiple unit cells arranged periodically from left to right to form a periodic structure. Each unit cell comprises an inner bushing, a first metal rubber, an outer bushing, and a second metal rubber. The first and second metal rubbers are symmetrically arranged and located within the outer bushing. At the ends of the shafting structure, the inner bushing degenerates into an end bushing.

[0008] Furthermore, the inner bushing includes a connecting shaft and a positioning ring. The positioning ring is provided in the middle of the connecting shaft. One end of the connecting shaft is inserted into the second metal rubber of a unit cell, and the other end of the connecting shaft is inserted into the first metal rubber of an adjacent unit cell.

[0009] Furthermore, the outer bushing is a cylinder with an annular boss provided in the middle of the cylinder; a first metal rubber mounting cavity for mounting the first metal rubber is provided on the left side of the annular boss; a second metal rubber mounting cavity for mounting the second metal rubber is provided on the right side of the annular boss.

[0010] Furthermore, the inner surface shape of the first metal rubber installation cavity matches the outer surface of the first metal rubber; the inner surface shape of the second metal rubber installation cavity matches the outer surface of the second metal rubber.

[0011] Furthermore, the first metal rubber and the second metal rubber are both truncated cone structures, with an inner hole for accommodating the connecting shaft in the middle of the truncated cone; the narrower ends of the first metal rubber and the second metal rubber are relatively arranged in the first metal rubber installation cavity and the second metal rubber installation cavity.

[0012] Furthermore, the vibration damping device further includes end bushings, one at each end of the vibration damping device. Each end bushing includes an end cap and a connecting end. The connecting end of the right end bushing is inserted into the inner hole of the wider end of the first metal rubber; the connecting end of the left end bushing is inserted into the inner hole of the wider end of the second metal rubber.

[0013] Furthermore, the number of the unit cells is not less than two, and the greater the number of unit cells, the better the vibration reduction effect.

[0014] Furthermore, the outer bushing, the inner bushing and the end bushing are all made of structural steel.

[0015] Furthermore, the first metal rubber and the second metal rubber may be metal rubbers with the same stiffness or different stiffness.

[0016] The beneficial effects of the present invention are: 1. The metal-rubber shafting structure of the present invention periodically arranges the metal rubber and inner and outer bushings, so that the metal-rubber shafting structure forms a periodic structure with a bandgap characteristic. When a vibration load is transmitted from one end of the metal-rubber shafting structure, the load transfer path undergoes vibration reduction through friction energy dissipation between the metal wires of the metal rubber and vibration bandgap reduction formed by the periodic structure. This allows the excitation load at a specific frequency to form a forbidden band, thereby achieving vibration reduction and broadening the frequency range of vibration reduction.

[0017] 2. The introduction of the periodic structure of the present invention improves the vibration reduction and isolation effects of the conventional metal rubber shock absorber structure, achieving vibration reduction over a wider frequency, which is suitable for wide-band vibration reduction requirements under extreme working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 yes Figure 1 Schematic diagram of the internal structure; Figure 3 It is a structural schematic diagram of the end bushing of the present invention; Figure 4 It is a structural schematic diagram of the inner bushing of the present invention; Figure 5 It is a schematic structural diagram of the outer bushing of the present invention; Figure 6 yes Figure 5 Schematic diagram of the internal structure; Figure 7 Schematic diagram of the structure of the metal rubber of the present invention; Figure 8 This is a frequency response function curve diagram of the metal rubber with the same stiffness of the present invention; Figure 9 This is a transfer characteristic curve diagram of the metal rubber with the same stiffness of the present invention; Figure 10 1. This is a graph showing different frequency response functions of the metal rubber stiffness of the present invention; Figure 11 It is a curve diagram of different transfer characteristics of the metal rubber stiffness of the present invention.

[0019] In the figure: 1. External bushing; 1-1. Annular boss; 1-2. First metal rubber mounting cavity; 1-3. Second metal rubber mounting cavity; 2. End bushing; 2-1. End cover; 2-2. Connecting end; 3. First metal rubber; 4. Second metal rubber; 5. Internal bushing; 5-1. Connecting shaft; 5-2. Positioning ring; 6. Load input area; 7. Load output area. DETAILED DESCRIPTION

[0020] like Figure 1 、 Figure 2As shown, this embodiment proposes a wide-band vibration damping device for a shaft system based on metal rubber. The device comprises multiple unit cells arranged periodically from left to right to form a periodic structure. Each unit cell comprises an inner bushing 5, an outer bushing 1, a first metal rubber 3, and a second metal rubber 4. The first and second metal rubbers 3 and 4 are symmetrically arranged and located within the outer bushing 1. At the ends of the shaft system structure, the inner bushing 5 degenerates into the end bushing 2.

[0021] like Figure 4 As shown, the internal bushing 5 includes a connecting shaft 5-1 and a positioning ring 5-2. A positioning ring 5-2 is provided in the middle of the connecting shaft 5-1. One end of the connecting shaft 5-1 is inserted into the second metal rubber 4 of a unit cell, and the other end of the connecting shaft 5-1 is inserted into the first metal rubber 3 of the adjacent unit cell.

[0022] like Figure 5 、 Figure 6 As shown, the outer bushing 1 is cylindrical, with an annular boss 1-1 located in the center. A first metal rubber mounting cavity 1-2 is located on the left side of the annular boss for mounting a first metal rubber 3. A second metal rubber mounting cavity 1-3 is located on the right side of the annular boss for mounting a second metal rubber 4. The inner surface of the first metal rubber mounting cavity 1-2 matches the outer surface of the first metal rubber 3; the inner surface of the second metal rubber mounting cavity 1-3 matches the outer surface of the second metal rubber 4.

[0023] like Figure 7 As shown, the first metal rubber 3 and the second metal rubber 4 are both truncated cone structures, and an inner hole for accommodating the connecting shaft 5-1 is provided in the middle of the truncated cone; the narrower ends of the first metal rubber 3 and the second metal rubber 4 are relatively arranged in the first metal rubber mounting cavity 1-3 and the second metal rubber mounting cavity 1-2.

[0024] like Figure 3 As shown, this embodiment also includes end bushings 2, and the two end bushings 2 are respectively located at the two ends of the vibration damping device. At the end, each end bushing 2 includes an end cover 2-1 and a connecting end 2-2. The connecting end 2-2 of the right end bushing 2 is inserted into the inner hole of the wider end of the first metal rubber 3; the connecting end 2-2 of the left end bushing 2 is inserted into the inner hole of the wider end of the second metal rubber 4.

[0025] The vibration load transmission path is as follows: The vibration load transmission path begins at load input area 6, passing sequentially through inner bushing 5 (the end connected to second metal rubber 4), second metal rubber 4, outer bushing 1, first metal rubber 3, and inner bushing 5 (the end connected to first metal rubber 3), forming a cycle. This process ultimately leads to load output area 7. As the load enters and exits the end of the periodic structure, inner bushing 5 degenerates into end bushing 2. This ensures that the vibration load not only dissipates energy and vibrations through the metal rubber, causing friction between the internal wires under load, but also propagates through the periodic structure, creating band gaps that dampen vibrations, thereby enhancing the metal rubber's vibration damping effect.

[0026] The metal-rubber shafting structure arranges the inner bushing 5, the first metal rubber 3, the outer bushing 1, and the second metal rubber 4 in a periodic arrangement. The stiffness, relative density, and configuration of the first metal rubber 3 and the second metal rubber 4 can be adjusted. Within one period, the stiffness of the first metal rubber 3 and the second metal rubber 4 can be different. By adjusting the mechanical properties of the metal-rubber shafting structure through parameters such as the relative density, stiffness, and configuration of the metal rubber, the energy dissipation effect and band gap characteristics of the metal-rubber shafting structure are changed, resulting in a more targeted vibration reduction effect and a wider vibration reduction frequency range.

[0027] Example: First, after installing the first metal rubber 3 on the end bushing 2, the outer bushing 1 is inserted. The first metal rubber 3 is installed in the first metal rubber installation cavity 1-3 on the right side of the annular boss 1-1; the second metal rubber 4 is installed in the second metal rubber installation cavity 1-2 on the left side of the annular boss 1-1; the narrower ends of the first metal rubber 3 and the second metal rubber 4 are arranged opposite each other; one end of the connecting shaft 5-1 of the internal bushing 5 is inserted into the inner hole of the first metal rubber 3, and the other end is inserted into the inner hole of the second metal rubber 4 of an adjacent unit cell. The two adjacent unit cells are connected together to form a metal rubber shaft system structure with metal rubbers and bushings arranged in a periodic manner. In this periodic structure, the period parameters can be adjusted according to actual conditions, and the parameters of the first metal rubber 3 and the second metal rubber 4 can be different.

[0028] This embodiment selects a metal rubber shafting structure with 4 cycles for analysis. In the metal rubber shafting structure, the load is transferred from one end ( Figure 2 , the load is introduced into the area 6 position), and from the other end ( Figure 2 , the load is transmitted from the load transmission area 7), an internal bushing 5 is selected inside the metal rubber shafting structure, and an end bushing 2 is used to provide a metal rubber vibration excitation load and output load interface at the end.

[0029] Vibration reduction analysis of metal rubber shafting structure: The inner bushing 5, outer bushing 1, and end bushing 2 in the metal-rubber shafting structure are made of structural steel. The first metal rubber 3 and the second metal rubber 4 are formed by metal wire weaving, slotting, winding, and stamping. Equivalent parameters of the metal rubber were obtained through mechanical property testing using an equivalent model for analysis. The material parameters of the structural steel and the metal rubber are as follows:

[0030] The vibration reduction effect of the metal-rubber shafting structure is analyzed in two cases. In the first case, the stiffness of the first metal rubber 3 and the second metal rubber 4 on both sides of the outer bushing 1 is the same; in the second case, the stiffness of the first metal rubber 3 and the second metal rubber 4 on both sides of the outer bushing 1 is different. The following analysis is performed respectively: The first metal rubber 3 and the second metal rubber 4 on both sides of the outer bushing 1 have the same stiffness: A metal rubber with a stiffness of 5000N / mm was used to calculate and analyze the frequency response of the metal rubber shafting structure in the range of 0-5000Hz, and its transfer characteristic curve was calculated. The results are as follows: Apply axial excitation at one end of the periodic structure and calculate the frequency response of the metal-rubber shaft structure. Take any point on the metal-rubber shaft structure to calculate the frequency response of the metal-rubber shaft structure, and obtain peak values ​​at 550Hz, 1064Hz, 1493Hz, and 2887Hz, as shown in the following example: Figure 8 shown.

[0031] Based on the applied axial load, the input excitation at one end is compared with the output excitation at the other end. The comparison formula is as follows:

[0032] According to the excitation acceleration at the end, the transfer characteristic curve is as follows: Figure 9 shown.

[0033] The first metal rubber 3 and the second metal rubber 4 on both sides of the outer bushing 1 have different stiffnesses: Figure 10 When the stiffness of the first metal rubber 3 and the second metal rubber 4 are different, the stiffness of the first metal rubber 3 is 5000N / mm, and the stiffness of the second metal rubber 4 is 7000N / mm, the frequency response characteristics of the metal rubber shaft structure are calculated. The load excitation form is axial excitation, and the excitation input and output ends are as follows: Figure 2 (2-6, 2-7), the structure produced peaks at 624Hz, 1205Hz, and 1680Hz.

[0034] The band gap characteristics of the metal rubber shaft structure are as follows Figure 11As shown in the figure, the metal-rubber shafting structure periodically arranges the metal rubber and bushings, creating a periodic structure. This periodic structure exhibits a bandgap characteristic, creating a band gap for excitation loads at specific frequencies, thereby achieving vibration reduction and broadening the frequency range. The introduction of this periodic structure enhances the vibration reduction and isolation performance of conventional metal-rubber damper structures, achieving vibration reduction over a wider frequency range.

[0035] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical content disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement of the above embodiments made according to the technical essence of the present invention, within the spirit and principles of the present invention, without departing from the content of the technical solution of the present invention, shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A wide-band vibration damping device for shafting based on metal rubber, characterized in that: The vibration damping device comprises a plurality of unit cells, which are arranged periodically from left to right to form a periodic structure. Each unit cell comprises an inner bushing (5), a first metal rubber (3), an outer bushing (1) and a second metal rubber (4). The first metal rubber (3) and the second metal rubber (4) are symmetrically arranged and located inside the outer bushing (1).

2. The wide-band vibration damping device for shafting based on metal rubber according to claim 1, characterized in that: The inner bushing (5) comprises a connecting shaft (5-1) and a positioning ring (5-2). The positioning ring (5-2) is provided in the middle of the connecting shaft (5-1). One end of the connecting shaft (5-1) is inserted into the second metal rubber (4) of a vibration-damping unit cell, and the other end of the connecting shaft (5-1) is inserted into the first metal rubber (3) of an adjacent vibration-damping unit cell.

3. The wide-band vibration damping device for shafting based on metal rubber according to claim 1, characterized in that: The outer bushing (1) is a cylindrical body, and an annular boss (1-1) is provided in the middle of the cylindrical body; a second metal rubber installation cavity (1-2) is provided on the left side of the annular boss (1-1); and a first metal rubber installation cavity (1-3) is provided on the right side of the annular boss (1-1).

4. The metal rubber-based wide-band vibration damping device for shafting according to claim 3, characterized in that: The inner surface shape of the first metal rubber installation cavity (1-2) matches the outer surface of the first metal rubber (3); the inner surface shape of the second metal rubber installation cavity (1-3) matches the outer surface of the second metal rubber (4).

5. The metal rubber-based wide-band vibration damping device for shafting according to claim 4, characterized in that: The first metal rubber (3) and the second metal rubber (4) are both truncated cone structures, with an inner hole for accommodating the connecting shaft (5-1) being provided in the middle of the truncated cone; the narrower ends of the first metal rubber (3) and the second metal rubber (4) are arranged relative to each other in the first metal rubber installation cavity (1-3) and the second metal rubber installation cavity (1-2).

6. The wide-band vibration damping device for shafting based on metal rubber according to claim 1, characterized in that: The vibration damping device further comprises end bushings (2), and the two end bushings (2) are respectively located at two ends of the vibration damping device.

7. The wide-band vibration damping device for shafting based on metal rubber according to claim 6, characterized in that: Each end bushing (2) comprises an end cover (2-1) and a connecting end (2-2), wherein the connecting end (2-2) located on the right end bushing (2) is inserted into the inner hole of the wider end of the first metal rubber (3); and the connecting end (2-2) located on the left end bushing (2) is inserted into the inner hole of the wider end of the second metal rubber (4).

8. The wide-band vibration damping device for shafting based on metal rubber according to claim 1, characterized in that: The number of the vibration-damping unit cells is no less than two.

9. The wide-band vibration damping device for shafting based on metal rubber according to claim 1, characterized in that: The outer bushing (5) and the inner bushing (1) are both made of structural steel.

10. The wide-band vibration damping device for shafting based on metal rubber according to claim 1, characterized in that: The first metal rubber (3) and the second metal rubber (4) are metal rubbers having the same stiffness or different stiffness.

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