Arc-shaped rubber damping connector with sleeve type flow guide structure

Abstract

The application discloses an arc-shaped rubber damping connecting pipe with a sleeve type flow guide structure, which comprises an arc-shaped rubber damping pipe body and a sleeve type flow guide structure arranged in the arc-shaped rubber damping pipe body. The sleeve type flow guide structure comprises an inlet end rigid flow guide pipe, an outlet end rigid flow guide pipe and a middle flexible flow guide pipe. The inlet end rigid flow guide pipe is arranged in the interior of the inlet end of the arc-shaped rubber damping pipe body, and the outlet end rigid flow guide pipe is arranged in the interior of the outlet end of the arc-shaped rubber damping pipe body. The middle flexible flow guide pipe is arranged between the inlet end rigid flow guide pipe and the outlet end rigid flow guide pipe, and one end of the middle flexible flow guide pipe is fixedly connected with the inlet end rigid flow guide pipe, and the other end of the middle flexible flow guide pipe is freely inserted into the interior of the outlet end rigid flow guide pipe. The sleeve type flow guide structure can effectively reduce the flow-induced vibration of the arc-shaped damping connecting pipe caused by the structural characteristics of the variable cross section under the premise of providing three-way large displacement compensation capability, and improve the damping effect of the arc-shaped damping connecting pipe in the low frequency band.

Description

Technical Field

[0001] This invention relates to the field of vibration damping nozzle technology, specifically to an arc-shaped rubber vibration damping nozzle with a sleeve-type flow guide structure. Background Technology

[0002] Arc-shaped rubber vibration damping connectors are vibration damping elements used in pipeline liquid transmission, including single-arc, double-arc, and multi-arc types (such as...). Figures 1 to 3 As shown in the figure, it has the characteristics of good vibration reduction performance and outstanding displacement compensation capability. Compared with the straight-through rubber vibration damping pipe, it has a better displacement compensation capability and can simultaneously meet the requirements of large axial tensile, axial compression and radial shear displacement compensation. It can compensate for installation errors and vibration and impact displacement between equipment and pipelines, and has been widely used in engineering.

[0003] However, in practical applications, the applicant found that the arc-shaped vibration damping nozzle sometimes exhibits significant vibration excitation at certain frequencies in the low-frequency range, severely affecting the vibration damping effect. After research and analysis, the applicant discovered that the root cause of this problem is the variable cross-section structural characteristics of the arc-shaped vibration damping nozzle. This causes changes in flow velocity and turbulence in the fluid medium flowing within the nozzle, resulting in flow-induced vibration and consequently reducing the vibration damping effect of the arc-shaped vibration damping nozzle.

[0004] To address the aforementioned issues, the applicant proposed an arc-shaped rubber vibration damping nozzle with a sleeve-type flow guide structure. By arranging a flexible sleeve-type flow guide structure inside the arc-shaped rubber vibration damping nozzle that can meet the requirements of three-dimensional large displacement compensation, without changing the interface size, length, stiffness characteristics, and displacement compensation capability of the original arc-shaped vibration damping nozzle, this flexible flow guide structure can move freely and bend as the nozzle undergoes large axial tensile, compression, or shear deformation, while maintaining continuous and effective equal cross-sectional connectivity, thereby improving the vibration damping performance of the arc-shaped rubber vibration damping nozzle. Summary of the Invention

[0005] The purpose of this invention is to provide an arc-shaped rubber vibration damping nozzle with a sleeve-type flow guiding structure, which solves the problem in the prior art that the existing arc-shaped rubber vibration damping nozzles have poor vibration isolation effect due to flow-induced vibration caused by the structural characteristics of variable cross-section.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An arc-shaped rubber vibration damping pipe with a sleeve-type flow guiding structure includes an arc-shaped rubber vibration damping pipe body. The arc-shaped rubber vibration damping pipe body is provided with a sleeve-type flow guiding structure. The sleeve-type flow guiding structure includes an inlet rigid flow guiding pipe, an intermediate flexible flow guiding pipe, and an outlet rigid flow guiding pipe. The inlet rigid flow guiding pipe is located inside the inlet end of the arc-shaped rubber vibration damping pipe body. The outlet rigid flow guiding pipe is located inside the outlet end of the arc-shaped rubber vibration damping pipe body. The intermediate flexible flow guiding pipe is located between the inlet rigid flow guiding pipe and the outlet rigid flow guiding pipe, with one end fixedly connected to the inlet rigid flow guiding pipe and the other end freely inserted inside the outlet rigid flow guiding pipe.

[0007] Furthermore, the inlet end rigid guide tube is a thin metal tube, and one end of it is provided with a first flange for engaging with the first flange stop provided at the inlet end of the arc-shaped rubber damping tube body, and the other end of it is vulcanized and composited with the intermediate flexible guide tube.

[0008] Furthermore, the rigid guide tube at the outlet end is a thin metal tube, and one end of it is provided with a second flange for engaging with the second flange stop provided at the outlet end of the arc-shaped rubber damping tube body, and the other end of it is sleeved on the intermediate flexible guide tube.

[0009] Furthermore, the rigid guide tube at the inlet end has several first damping holes circumferentially opened on its tube wall to connect the internal flow channel of the sleeve-type guide structure and the cavity between the sleeve-type guide structure and the arc-shaped rubber damping tube body.

[0010] Furthermore, the rigid guide tube at the outlet end has several second damping holes circumferentially opened on its tube wall to connect the internal flow channel of the sleeve-type guide structure and the cavity between the sleeve-type guide structure and the arc-shaped rubber vibration damping tube body.

[0011] Furthermore, the intermediate flexible guide tube is a thin rubber tube, including an inner rubber layer, a skeleton layer and an outer rubber layer. The inner wall of the inner rubber layer is flush with the inner wall of the rigid guide tube at the inlet end. The skeleton layer is attached to the outer surface of the inner rubber layer, and the outer rubber layer is attached to the outer surface of the skeleton layer.

[0012] Furthermore, a first washer is provided inside the first flange, and the first washer and the first flange are vulcanized together.

[0013] Furthermore, a second washer is provided inside the second flange, and the second washer and the second flange are vulcanized together.

[0014] Compared with the prior art, the advantages of the present invention are as follows: by setting the sleeve-type flow guide structure, the flow velocity of the fluid medium in the arc-shaped rubber vibration damping pipe can be stabilized, the flow-induced vibration can be reduced, and the vibration damping effect of the arc-shaped rubber vibration damping pipe in the low frequency range can be improved. At the same time, it does not affect the displacement compensation capability of the original arc-shaped rubber vibration damping pipe, nor does it increase the stiffness of the original arc-shaped rubber vibration damping pipe. After experiencing large displacement conditions, it can automatically reset and work normally without manual intervention.

[0015] The arc-shaped rubber vibration damping nozzle with sleeve-type flow guiding structure provided by this invention is an innovative structure proposed to address the shortcomings of existing arc-shaped rubber vibration damping nozzles, which are prone to flow-induced vibration and have poor low-frequency vibration damping performance due to their variable cross-section structure. The specific innovations are as follows: (1) Without changing the interface size, length, stiffness characteristics and displacement compensation capability of the original arc-shaped vibration damping pipe, the original variable cross-section flow channel of the original arc-shaped vibration damping pipe can be changed to a constant cross-section flow channel by setting the sleeve-type flow guide structure, which eliminates the flow-induced vibration at the variable cross-section and improves the vibration damping performance of the arc-shaped vibration damping pipe.

[0016] (2) The sleeve-type flow guide structure adopts a movable design. When the arc-shaped rubber vibration damping pipe undergoes large axial tension, compression or shear deformation, it can move freely and bend flexibly with the arc-shaped rubber vibration damping pipe, while maintaining the continuity of the flow guide path. It does not increase the stiffness of the original arc-shaped rubber vibration damping pipe, and takes into account the original mechanical properties of the original arc-shaped rubber vibration damping pipe while ensuring the flow guide function.

[0017] (3) The intermediate flexible guide tube is made of high-strength fiber as the skeleton material and composite rubber on the upper and lower surfaces, with a wall thickness of only 1.3mm. Under the premise of ensuring that the diameter and flow rate remain basically unchanged, it has high tensile strength and tear resistance, and its service life is matched with that of the original vibration damping pipe (no less than 12 years in marine environment).

[0018] It should be noted that although there are similar vibration damping pipes with internal flow guiding structures in the prior art, the flow guiding structure design of such vibration damping pipes is mainly for purposes such as corrosion prevention, anti-adhesion, anti-scouring, and anti-wear, and does not involve the suppression of flow-induced vibration; while the flow guiding structure in this application is intended to reduce flow-induced vibration caused by variable cross-section and improve the vibration damping performance of the arc-shaped vibration damping pipe.

[0019] Furthermore, existing flow guiding structures are mostly discontinuous or fixed, and often use a single material (such as PTFE, nylon, rubber, or metal), making it difficult to balance the requirements of large displacement deformation, high strength, and long service life. The flow guiding structure provided in this application adopts a sleeve-type structure, which can maintain a constant cross-section connection for a long time under large displacement conditions, ensuring the continuity of the flow path and preventing interruption or failure due to pipe deformation; it is made of high-strength fiber as the skeleton and composite rubber material, which maintains flexibility while possessing excellent tensile strength and tear resistance, achieving long service life under large deformation conditions. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this embodiment, the accompanying drawings used in the description of the embodiment will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the existing single-arc curved rubber vibration damping pipe; Figure 2 This is a schematic diagram of the existing double-arc curved rubber vibration damping pipe; Figure 3 This is a schematic diagram of the existing multi-arc curved rubber vibration damping pipe; Figure 4 yes Figure 2 Enlarged view of point A in the middle; Figure 5 yes Figure 2 Enlarged view at point B in the middle; Figure 6 This is a cross-sectional view of an embodiment of the arc-shaped rubber vibration damping nozzle with sleeve-type flow guiding structure provided by the present invention; Figure 7 yes Figure 6 Enlarged view at point D; Figure 8 yes Figure 6 Enlarged view at point E in the middle; Figure 9 This is a schematic diagram of the sleeve-type flow guide structure; Figure 10 This is an exploded view of the sleeve-type flow guide structure; Figure 11 This is a cross-sectional view of the rigid guide tube at the inlet end; Figure 12 This is a cross-sectional view of the rigid guide tube at the outlet end; Figure 13 This is a schematic diagram showing the direction of fluid flow and the location of the pressure monitoring surface; Figure 14This is an internal velocity cloud diagram of an arc-shaped rubber vibration damping nozzle (with sleeve-type flow guide structure) with an inlet flow velocity of 1.0 m / s. Figure 15 yes Figure 14 Enlarged image; Figure 16 This is an internal velocity cloud diagram of an arc-shaped rubber vibration damping nozzle (with sleeve-type flow guide structure) with an inlet flow velocity of 2.0 m / s. Figure 17 yes Figure 16 Enlarged image; Figure 18 This is an internal velocity cloud diagram of an arc-shaped rubber vibration damping nozzle (without sleeve-type flow guide structure) with an inlet flow velocity of 1.0 m / s. Figure 19 This is a comparison curve of the vibration levels at both ends of the flange of the arc-shaped rubber vibration damping pipe before and after the flow guide improvement; Explanation of reference numerals in the attached drawings: 1. Arc-shaped rubber damping tube body; 101. Arc-shaped rubber tube body; 102. Inlet end fastening ring; 103. Outlet end fastening ring; 104. Intermediate reinforcing ring; 105. Inlet end flange; 106. Outlet end flange; 107. First flange stop; 108. Second flange stop; 201. Inlet end rigid guide tube; 201a. First flange; 201b. First damping hole; 201c. First step; 202. Intermediate flexible guide tube; 203. Outlet end rigid guide tube; 203a. Second flange; 203b. Second damping hole; 204. First washer; 205. Second washer; 3. Cavity. Detailed Implementation

[0022] To make the technical means, creative features, objectives and effects of this invention easier to understand, the following description, in conjunction with the accompanying drawings and specific embodiments, further explains how this invention is implemented.

[0023] Example: See Figures 6 to 12 This invention provides an arc-shaped rubber vibration damping pipe with a sleeve-type flow guide structure, including an arc-shaped rubber vibration damping pipe body 1. The arc-shaped rubber vibration damping pipe body 1 is provided with a sleeve-type flow guide structure 2 inside. The sleeve-type flow guide structure 2 includes an inlet rigid flow guide pipe 201, an intermediate flexible flow guide pipe 202, and an outlet rigid flow guide pipe 203. The inlet rigid flow guide pipe 201 is disposed inside the inlet end of the arc-shaped rubber vibration damping pipe body 1, and the outlet rigid flow guide pipe 203 is disposed inside the outlet end of the arc-shaped rubber vibration damping pipe body 1. The intermediate flexible flow guide pipe 202 is disposed between the inlet rigid flow guide pipe 201 and the outlet rigid flow guide pipe 203, with one end fixedly connected to the inlet rigid flow guide pipe 201 and the other end freely inserted inside the outlet rigid flow guide pipe 203.

[0024] The arc-shaped rubber vibration damping nozzle with sleeve-type flow guide structure provided in this application is specifically achieved by installing the sleeve-type flow guide structure provided in this application (connecting the inlet end rigid flow guide pipe 201 and the outlet end rigid flow guide pipe 203 through the intermediate flexible flow guide pipe 202) inside the existing arc-shaped rubber vibration damping nozzle. This maintains the uniform cross-section flow channel of the arc-shaped rubber vibration damping nozzle while meeting the requirements for large axial and radial displacement compensation of the arc-shaped rubber vibration damping nozzle.

[0025] Specifically, please continue reading Figure 6 , Figure 7 , Figures 9 to 11 The inlet end rigid guide tube 201 is a thin metal tube, and one end of it is provided with a first flange 201a, which is used to engage with the first flange stop 107 provided at the inlet end of the arc-shaped rubber vibration damping tube body 1. The other end of it is provided with a first step 201c, which is used to vulcanize and combine with the intermediate flexible guide tube 202 into one piece.

[0026] By using a vulcanization process, the rigid inlet guide pipe 201 and the intermediate flexible guide pipe 202 are combined into one unit, which can provide a straight flow channel for the arc-shaped rubber vibration damping pipe body 1 (i.e., the existing arc-shaped rubber vibration damping pipe). At the same time, it can ensure that the arc-shaped rubber vibration damping pipe body 1 (i.e., the existing arc-shaped rubber vibration damping pipe) can compensate for displacement in all directions under tilting and swaying conditions, thus meeting the requirements of safety and reliability.

[0027] Specifically, please continue reading Figure 6 , Figures 8 to 10 , Figure 12 The rigid guide tube 203 at the outlet end is a thin metal tube, and one end of it is provided with a second flange 203a, which is used to engage with the second flange stop 108 provided at the outlet end of the arc-shaped rubber damping tube body 1, and the other end of it is sleeved on the intermediate flexible guide tube 202.

[0028] Specifically, please continue reading Figure 6 and Figure 11 The rigid guide tube 201 at the inlet end has several first damping holes 201b circumferentially opened on its pipe wall. These holes are used to connect the internal flow channel of the sleeve-type guide structure 2 and the cavity 3 between the sleeve-type guide structure 2 and the arc-shaped rubber damping tube 1. This facilitates the entry of the fluid medium into the cavity 3 and balances the pressure inside and outside the sleeve-type guide structure 2. At the same time, the local resistance loss generated when the fluid medium flows through the first damping holes 201b attenuates the pressure pulsation and fluid excitation in the pipeline.

[0029] Specifically, please continue reading Figure 6 and Figure 12The rigid guide pipe 203 at the outlet end has several second damping holes 203b circumferentially opened on its pipe wall. These holes are used to connect the internal flow channel of the sleeve-type guide structure 2 and the cavity 3 between the sleeve-type guide structure 2 and the arc-shaped rubber damping pipe 1. This facilitates the flow of fluid medium out of the cavity 3 and the discharge of air from the cavity 3, thereby balancing the pressure inside and outside the sleeve-type guide structure 2. At the same time, the local resistance loss generated when the fluid medium flows through the second damping holes 203b is used to attenuate the pressure pulsation and fluid excitation in the pipeline.

[0030] It should be noted that the function of the first and second damping orifices is not limited to pressure balance; they also constitute fluid damping elements. When the fluid medium passes through the first and second damping orifices, the local resistance generated at the orifice converts the pressure pulsation energy of the fluid medium into heat energy dissipation, playing a role similar to the vibration reduction and noise reduction of damping orifices in a muffler. This further suppresses flow-induced vibration caused by variable cross-sections and improves the overall vibration reduction effect of the damping pipe. The diameter of the first and second damping orifices is 0.5 to 2 times the wall thickness of their respective rigid guide pipes, and the ratio of the total open area of ​​the first and second damping orifices to the cross-sectional area of ​​the entire sleeve-type guide structure is 10% to 40%.

[0031] Specifically, the intermediate flexible guide tube 202 is a thin rubber tube comprising an inner rubber layer, a reinforcing layer, and an outer rubber layer. The inner wall of the inner rubber layer is flush with the inner wall of the rigid guide tube 1 at the inlet end. The reinforcing layer is attached to the outer surface of the inner rubber layer, and the outer rubber layer is attached to the outer surface of the reinforcing layer. More specifically, both the inner and outer rubber layers are made of corrosion-resistant rubber materials; the reinforcing layer is made of high-strength fiber material to increase the strength and toughness of the intermediate flexible guide tube 202, effectively ensuring its shape recovery ability after stretching, compression, and shearing.

[0032] Specifically, please continue reading Figure 7 , Figure 9 and Figure 10 The first flange 201a has a first gasket 204 inside, and the first gasket 204 is vulcanized into one piece with the first flange 201a. The first gasket 204 is made of corrosion-resistant rubber material and is used to provide insulation when installed with the mating flange.

[0033] Specifically, please continue reading Figure 8 , Figure 9 and Figure 10 The second flange 203a has a second gasket 205 inside, and the second gasket 205 is vulcanized into one piece with the second flange 303a. The second gasket 205 is made of corrosion-resistant rubber material and is used to provide insulation when installed with the mating flange.

[0034] Specifically, the arc-shaped rubber vibration damping tube 1 can be any of the following forms: single-arc, double-arc, or multi-arc; wherein, when the arc-shaped rubber vibration damping tube 1 is a single-arc type, such as Figure 1 As shown, it consists of a single-arc rubber tube 101, an inlet end fastening ring 102, an outlet end fastening ring 103, an inlet end flange 105, and an outlet end flange 106; when the arc-shaped rubber vibration damping tube 1 is a double-arc type, as shown... Figure 2 As shown in Figure 3, the structure consists of a double-arc rubber tube 101, an inlet end fastening ring 102, an outlet end fastening ring 103, an intermediate reinforcing ring 104, an inlet end flange 105, and an outlet end flange 106. When the arc-shaped rubber vibration damping tube 1 is multi-arc, as shown in Figure 3, it consists of a multi-arc rubber tube 101, an inlet end fastening ring 102, an outlet end fastening ring 103, several intermediate reinforcing rings 104, an inlet end flange 105, and an outlet end flange 106. Figure 4 and Figure 5 In the process, regardless of whether the arc-shaped rubber vibration damping tube 1 is a single arc, double arc, or multi-arc type, a first flange stop 107 is provided at the inlet end of the arc-shaped rubber vibration damping tube 1, and a second flange stop 108 is provided at the outlet end.

[0035] It should be noted that since the arc-shaped rubber vibration damping pipe 1 used in this application is the arc-shaped rubber vibration damping pipe in the prior art, its structure is known, so its structure will not be described in detail in this application.

[0036] The assembly process of the arc-shaped rubber vibration damping nozzle with a sleeve-type flow guide structure provided in this embodiment of the invention is as follows: (1) Place the rigid guide tube 203 at the outlet end into the interior of the arc-shaped rubber damping tube body 1, and have the second flange 203a at its end engage with the second flange stop 108 at the outlet end of the arc-shaped rubber damping tube body 1. (2) Place the inlet end rigid guide tube 201 and the middle flexible guide tube 202 into the inlet end of the arc-shaped rubber vibration damping tube body 1, and make the first flange 201a provided at the end of the inlet end rigid guide tube 201 snap into the first flange stop 107 provided at the inlet end of the arc-shaped rubber vibration damping tube body 1, so that the end of the middle flexible guide tube 202 away from the inlet end rigid guide tube 201 is inserted into the outlet end rigid guide tube 203.

[0037] To verify the improved vibration reduction effect of the arc-shaped rubber vibration damping nozzle with sleeve-type flow guide structure provided by this invention, the applicant performed steady-state calculations on the flow fields of arc-shaped rubber vibration damping nozzles without and with sleeve-type flow guide structures. In this verification experiment, a velocity inlet and a pressure outlet were used as boundary conditions. The rated pressure of the arc-shaped rubber vibration damping nozzle was set to 1 MPa, the inlet velocity was set to 1 m / s and 2 m / s, and the outlet pressure was set to zero. The turbulence model was set to SST k-omega, and the pressure-velocity coupling algorithm was selected using the SIMPLE algorithm. Fluid temperature changes were not considered. The calculation iteration count was set to 500, and physical quantities were selected for monitoring to ensure calculation accuracy. Corresponding monitoring surfaces were set at the inlet and outlet ends of the arc-shaped rubber vibration damping nozzle to monitor pressure changes. The fluid flow direction and monitoring surface positions are as follows: Figure 13 As shown.

[0038] Calculation results show that the flow velocity of the fluid medium inside the sleeve-type flow guide structure 2 of the arc-shaped rubber vibration damping nozzle with sleeve-type flow guide structure provided in this embodiment of the invention is relatively stable (e.g., Figures 14 to 17 The red portion in the middle shows almost no flow within the cavity 3 between the sleeve-type flow guide structure 2 and the arc-shaped rubber damping tube 1 (e.g., Figures 14 to 17 (The blue section in the middle). The flow velocity of the fluid medium within the arc-shaped rubber vibration damping nozzle without a sleeve-type flow guide structure is not very stable, and local turbulence exists (such as...). Figure 18 (Red part). Figure 14 The diagram shown is a velocity contour map inside an arc-shaped rubber vibration damping nozzle with a sleeve-type flow guide structure when the inlet flow velocity is 1 m / s. Figure 15 yes Figure 14 A magnified view of a portion of the image; Figure 16 The diagram shown is a velocity contour map inside an arc-shaped rubber vibration damping nozzle with a sleeve-type flow guide structure when the inlet flow velocity is 2 m / s. Figure 17 yes Figure 16 A magnified view of a portion of the image; Figure 18 The diagram shows the velocity contour inside the arc-shaped rubber vibration damping nozzle without a sleeve-type flow guide structure when the inlet flow velocity is 1 m / s.

[0039] Using the pressure-velocity coupled SIMPLE algorithm, after 500 iterations for inlet velocities of 1 m / s and 2 m / s respectively, the average inlet and outlet pressures of the arc-shaped rubber vibration damping nozzles with and without sleeved flow guide structures reached a stable state. Specifically, when the inlet flow velocity was 1 m / s, after 500 iterations, the pressure drop of the arc-shaped rubber vibration damping nozzle with sleeved flow guide structure was 26 Pa, and the pressure drop of the arc-shaped rubber vibration damping nozzle without sleeved flow guide structure was 1348 Pa; when the inlet flow velocity was 2 m / s, after 500 iterations, the pressure drop of the arc-shaped rubber vibration damping nozzle with sleeved flow guide structure was 120 Pa, and the pressure drop of the arc-shaped rubber vibration damping nozzle without sleeved flow guide structure was 6523 Pa. In short, compared to the rated pressure of 1 MPa for the arc-shaped rubber vibration damping nozzle, when the inlet flow velocity is 1 m / s, the pressure loss of the arc-shaped rubber vibration damping nozzle with the sleeve-type flow guide structure is only 0.0026%, while the pressure loss of the arc-shaped rubber vibration damping nozzle without the sleeve-type flow guide structure is 0.135%. When the inlet flow velocity is 2 m / s, the pressure loss of the arc-shaped rubber vibration damping nozzle with the sleeve-type flow guide structure is only 0.012%, while the pressure loss of the arc-shaped rubber vibration damping nozzle without the sleeve-type flow guide structure is 0.65%. This demonstrates that installing the sleeve-type flow guide structure can significantly improve the local turbulence of the existing arc-shaped rubber vibration damping nozzle, resulting in a marked improvement in the overall vibration reduction effect.

[0040] In addition, to verify the improvement of the low-frequency vibration reduction capability of the sleeve-type flow guide structure on the low-frequency band of the arc-shaped rubber vibration damping pipe, the applicant also tested the vibration level difference between the arc-shaped rubber vibration damping pipe without the sleeve-type flow guide structure and the arc-shaped rubber vibration damping pipe with the sleeve-type flow guide structure. The test results showed that adding the sleeve-type flow guide structure can significantly improve the low-frequency vibration reduction capability of the existing arc-shaped rubber vibration damping pipe and significantly improve the overall vibration reduction capability.

[0041] Figure 19The diagram shows a comparison of the vibration levels at both flanges of the arc-shaped rubber vibration damping nozzle before and after the flow guide improvement. Specifically, it compares the vibration levels at both flanges of the arc-shaped rubber vibration damping nozzle without the sleeve-type flow guide structure (before the improvement) and the arc-shaped rubber vibration damping nozzle with the sleeve-type flow guide structure (after the improvement). In the diagram: the dark green solid curve and the purple dashed curve represent the vibration levels at the near-pump end (inlet end) and far-pump end (outlet end) of the original pipe (i.e., the arc-shaped rubber vibration damping nozzle without the sleeve-type flow guide structure), respectively; the light green dashed curve and the red solid curve represent the vibration levels at the near-pump end (inlet end) and far-pump end (outlet end) of the improved pipe (i.e., the arc-shaped rubber vibration damping nozzle with the sleeve-type flow guide structure), respectively. Vibration level at the pump end (i.e., outlet end); the horizontal axis represents frequency in Hz; the vertical axis represents vibration acceleration level in dB; the near-pump end before the flow guide indicates the vibration level measured on the flange of the arc-shaped rubber vibration damping connector closest to the vibration excitation source before the sleeve-type flow guide structure is installed; the far-pump end before the flow guide indicates the vibration level measured on the flange of the arc-shaped rubber vibration damping connector furthest from the vibration excitation source before the sleeve-type flow guide structure is installed; the near-pump end after the flow guide indicates the vibration level measured on the flange of the arc-shaped rubber vibration damping connector closest to the vibration excitation source after the sleeve-type flow guide structure is installed; the far-pump end after the flow guide indicates the vibration level measured on the flange of the arc-shaped rubber vibration damping connector furthest from the vibration excitation source after the sleeve-type flow guide structure is installed.

[0042] from Figure 19 It can be seen that the frequencies and amplitudes of the dark green solid curve and the light green dashed curve are very close, meaning that the vibration level curves at the pump end of the arc-shaped rubber vibration damping connector basically overlap before and after the flow guide improvement, indicating that the vibration source characteristics have not changed significantly. In the 10–70Hz and 140–180Hz frequency bands (i.e., the area within the blue dashed box), where the original arc-shaped rubber vibration damping connector (i.e., without the sleeve-type flow guide structure) had an unsatisfactory vibration isolation effect (i.e., the dark green solid curve and the purple dashed curve are similar with no significant difference), the original arc-shaped rubber vibration damping connector… The vibration level at the far pump end of the vibrating pipe (i.e., before the sleeve-type flow guide structure was installed) was significantly improved after the flow guide structure was installed (from the purple dashed curve to the red solid curve). Among them, the vibration isolation effect was improved by 4.9dB, 3.2dB and 13.2dB in the three frequency bands (10Hz, 12.5Hz and 160Hz) where the vibration level drop effect was the worst. This shows that the sleeve-type flow guide structure has a good improvement on the low-frequency vibration isolation effect of the existing arc-shaped rubber vibration damping pipe.

[0043] Finally, it should be noted that the above description is only an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. An arc-shaped rubber vibration damping pipe with a sleeve-type flow guiding structure, comprising an arc-shaped rubber vibration damping pipe body (1), characterized in that, The arc-shaped rubber vibration damping tube (1) is provided with a sleeve-type flow guide structure (2). The sleeve-type flow guide structure (2) includes an inlet rigid flow guide tube (201), an intermediate flexible flow guide tube (202), and an outlet rigid flow guide tube (203). The inlet rigid flow guide tube (201) is located inside the inlet end of the arc-shaped rubber vibration damping tube (1). The outlet rigid flow guide tube (203) is located inside the outlet end of the arc-shaped rubber vibration damping tube (1). The intermediate flexible flow guide tube (202) is located between the inlet rigid flow guide tube (201) and the outlet rigid flow guide tube (203), with one end fixedly connected to the inlet rigid flow guide tube (201) and the other end freely inserted inside the outlet rigid flow guide tube (203).

2. The arc-shaped rubber vibration damping nozzle with sleeve-type flow guide structure according to claim 1, characterized in that, The inlet end rigid guide tube (201) is a thin metal tube, and one end of it is provided with a first flange (201a) for engaging with the first flange stop (107) provided at the inlet end of the arc-shaped rubber damping tube body (1). The other end of it is vulcanized and combined with the intermediate flexible guide tube (202) into one piece.

3. The arc-shaped rubber vibration damping nozzle with sleeve-type flow guide structure according to claim 1, characterized in that, The rigid guide tube (203) at the outlet end is a thin metal tube, and one end of it is provided with a second flange (203a) for engaging with the second flange stop (108) provided at the outlet end of the arc-shaped rubber damping tube body (1), and the other end of it is sleeved on the intermediate flexible guide tube (202).

4. The arc-shaped rubber vibration damping nozzle with sleeve-type flow guide structure according to claim 1, characterized in that, The rigid guide tube (201) at the inlet end has several first damping holes (201b) circumferentially opened on the tube wall, which are used to connect the internal flow channel of the sleeve-type guide structure (2) and the cavity (3) between the sleeve-type guide structure (2) and the arc-shaped rubber damping tube (1).

5. The arc-shaped rubber vibration damping nozzle with sleeve-type flow guide structure according to claim 1, characterized in that, The rigid guide tube (203) at the outlet end has several second damping holes (203b) circumferentially opened on the tube wall, which are used to connect the internal flow channel of the sleeve-type guide structure (2) and the cavity (3) between the sleeve-type guide structure (2) and the arc-shaped rubber damping tube (1).

6. The arc-shaped rubber vibration damping nozzle with sleeve-type flow guide structure according to claim 1, characterized in that, The intermediate flexible guide tube (202) is a thin rubber tube, including an inner rubber layer, a skeleton layer and an outer rubber layer. The inner wall of the inner rubber layer is flush with the inner wall of the inlet end rigid guide tube (201). The skeleton layer is attached to the outer surface of the inner rubber layer and the outer rubber layer is attached to the outer surface of the skeleton layer.

7. The arc-shaped rubber vibration damping nozzle with sleeve-type flow guide structure according to claim 2, characterized in that, The first flange (201a) is provided with a first washer (204), and the first washer (204) and the first flange (201a) are vulcanized into one piece.

8. The arc-shaped rubber vibration damping nozzle with sleeve-type flow guide structure according to claim 3, characterized in that, The second flange (203a) is provided with a second washer (205), and the second washer (205) and the second flange (203a) are vulcanized together.

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