A hinge type bellows expansion joint having anti-vibration fatigue characteristics

Abstract

The application discloses a hinge type bellows expansion joint with anti-vibration fatigue characteristics and relates to the technical field of expansion joints. The hinge type bellows expansion joint comprises a bellows, a sleeve, a floating unit and a fixed arm, one end of the fixed arm towards the center side of the bellows is provided with an extension unit, the end of the extension unit away from the fixed arm is provided with a pin shaft, the sleeve wall surface is fixedly connected with protruding parts, the protruding parts are rotationally connected with sleeves, the pin shaft is slidingly arranged in the sleeves, four protruding parts are fixedly arranged on the sleeve periphery along the axial direction of the sleeve, when the bellows is bent, the floating unit drives the sleeve to move, so that the pin shaft can move towards the bending deformation position of the bellows, the deviation between the axial center of the pin shaft and the bending deformation position of the bellows is reduced, and the shearing wear of the pin shaft is reduced; in addition, the extension unit is arranged, when the bellows is axially offset, the extension unit can make the sliding arm offset to a certain extent, so that the shearing force of the pin shaft along the axial direction of the bellows is prevented.

Description

Technical Field

[0001] This invention relates to the field of expansion joint technology, and specifically to a hinged bellows expansion joint with vibration fatigue resistance. Background Technology

[0002] An expansion joint is a flexible element that effectively compensates for axial deformation. For example, expansion joints welded to the shell of a fixed tubesheet heat exchanger have high axial flexibility and are easily deformable. They can compensate for the thermal expansion difference between the tubes and the shell caused by the different wall temperatures, reducing their axial load and thus reducing the thermal stress on the tubes, tubesheet, and shell, preventing strength failure, instability failure, and tube pull-out failure. There are many types of expansion joints, commonly including corrugated, welded ring plate, and clamp-type structures. Corrugated expansion joints are the most widely used, while welded ring plate expansion joints are only suitable for atmospheric or low-pressure applications. Expansion joints are also commonly called compensators or expansion joints. They consist of a bellows (an elastic element) that forms the main working body, and accessories such as end pipes, supports, flanges, and guide pipes. Expansion joints are flexible structures installed on the shell of a container or pipeline to compensate for the additional stress caused by temperature differences and mechanical vibration. Utilizing the effective expansion and contraction deformation of its main working body, the corrugated pipe, it absorbs dimensional changes in pipelines, ducts, and containers caused by thermal expansion and contraction, or compensates for axial, lateral, and angular displacements of pipelines, ducts, and containers. It can also be used for noise reduction and vibration damping, and in heating systems. To prevent pipeline deformation or damage due to thermal expansion or temperature stress when heating pipelines heat up, compensators need to be installed on the pipelines to compensate for thermal expansion, thereby reducing the stress on the pipe walls and the forces acting on valves or support structures.

[0003] Hinged expansion joints are a special type of bellows expansion joint designed to absorb angular displacement (angular deflection) in piping systems. When a piping system bends (angular displacement) due to thermal expansion and contraction, the hinged expansion joint connected to the pipe rotates (deflects) around its pivot pin. The bellows adapts to this angular change through its own bending deformation. Existing hinged expansion joints force the bellows to rotate axially around the pivot pin. However, during actual deformation, the bending deformation position of the bellows is not located in the plane of the pivot pin's axis. This results in the pivot pin being subjected to significant shear force, which accelerates pivot pin wear and affects the service life of the expansion joint. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention is proposed. Therefore, the purpose of the present invention is to provide a hinged bellows expansion joint with vibration fatigue resistance. The problem to be solved is that the existing hinged expansion joints force the bellows to rotate axially around the pin. However, during actual deformation, the bending deformation position of the bellows is not located in the plane of the pin's axis. This results in the pin being subjected to large shear forces, which in turn accelerates pin wear and affects the service life of the expansion joint.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a hinged bellows expansion joint with vibration fatigue resistance, comprising a bellows, and further comprising:

[0006] A sleeve is fitted around the periphery of the corrugated pipe, and the inner diameter of the sleeve is larger than the outer diameter of the corrugated pipe;

[0007] A floating unit is provided on the sleeve and is used to drive the sleeve to move around the periphery of the bellows when the bellows is bent and deformed.

[0008] The fixed arm has four parts, which are installed in pairs at both ends of the bellows. The end of the fixed arm facing the center of the bellows is provided with a telescopic unit. The end of the telescopic unit away from the fixed arm is provided with a pin. The sleeve wall is fixedly connected to a protrusion. The protrusion is rotatably connected to a sleeve. The pin slides through the sleeve. The four protrusions are arrayed along the axial direction of the sleeve and fixedly connected to the periphery of the sleeve.

[0009] As a preferred embodiment of the hinged bellows expansion joint with vibration fatigue resistance of the present invention, the floating unit includes a fixed ring coaxially fixed to both ends of the sleeve. The fixed ring is integrally formed and fixed with a tapered portion. The outer diameter of the tapered portion increases sequentially in the direction away from the center of the bellows. The tapered edge of the tapered portion is provided with multiple notches. The smallest end of the outer diameter of the tapered portion is rotatably embedded with a compression ball. The compression ball rolls in contact with the periphery of the bellows.

[0010] As a preferred embodiment of the hinged bellows expansion joint with vibration fatigue resistance described in this invention, wherein the notch grooves are arranged in an array along the axial direction of the cone portion.

[0011] As a preferred embodiment of the hinged bellows expansion joint with anti-vibration fatigue characteristics described in this invention, the telescopic unit includes a sliding arm that slidably passes through a sliding cavity opened in the fixed arm, a pin is mounted on the sliding arm, an elastic element is installed in the sliding cavity, and the elastic element imparts potential energy to the sliding arm to move toward the center of the bellows.

[0012] As a preferred embodiment of the hinged bellows expansion joint with anti-vibration fatigue characteristics described in this invention, wherein: one end of the sliding arm that enters the sliding cavity is fixedly connected to a limiting pin, and the fixed arm has an oblong hole for the limiting pin to be inserted.

[0013] As a preferred embodiment of the hinged bellows expansion joint with anti-vibration fatigue characteristics described in this invention, the elastic element is a spring installed in the sliding cavity, and the spring elastically abuts against the sliding arm.

[0014] As a preferred embodiment of the hinged bellows expansion joint with vibration fatigue resistance described in this invention, the longitudinal section of the sliding arm is rectangular.

[0015] As a preferred embodiment of the hinged bellows expansion joint with anti-vibration fatigue characteristics described in this invention, the pin shaft is provided with multiple diameter-changing slots around its periphery, and a diameter-changing hole is coaxially provided at the end of the pin shaft away from the sliding arm. The diameter-changing slots are connected to the diameter-changing hole. The sliding arm is provided with an expansion unit for expanding the pin shaft, so that after the pin shaft is expanded, the periphery of the pin shaft abuts against the inner hole of the sleeve.

[0016] As a preferred embodiment of the hinged bellows expansion joint with vibration fatigue resistance of the present invention, wherein: the expansion unit includes a cylinder mounted on the sliding arm, the cylinder rod of the cylinder slidably penetrates the pin and is fixedly connected to a tapered portion, and the outer diameter of the tapered portion increases sequentially in the direction away from the sliding arm.

[0017] As a preferred embodiment of the hinged bellows expansion joint with anti-vibration fatigue characteristics described in this invention, wherein: a sensing block is fixedly connected to the sleeve wall, a sensing switch is installed on the sliding arm, and the sensing switch is used in conjunction with the sensing block.

[0018] 1. This invention, by setting up a sleeve and a floating unit, when the bellows bends, the floating unit will drive the sleeve to move, so that the pin can move towards the bending deformation position of the bellows, reducing the deviation between the plane where the pin's axis is located and the bending deformation position of the bellows, thereby reducing the shear wear on the pin. In addition, a telescopic unit is also set up. When the bellows causes axial displacement, the telescopic unit can cause the sliding arm to shift to a certain extent, preventing a large shear force along the axial direction of the bellows from being generated on the pin.

[0019] 2. In this invention, by setting extrusion balls, a cone, and a retaining ring, when the bellows is bent, the position of its bending deformation may deviate far from the pin shaft, causing the pin shaft to be subjected to a large shear force when the bellows bends around the pin shaft's axial direction. Therefore, when the bellows is bent, the axial directions of the two ends of the bellows will be at an angle, causing the extrusion balls to roll on the periphery of the bellows and drive the sleeve to move, causing the sleeve to move towards the bending deformation position of the bellows. This reduces the deviation between the pin shaft and the bending deformation position of the bellows, thereby at least to a certain extent reducing the shear wear on the pin shaft.

[0020] 3. In this invention, a tapered portion and a cylinder are provided. The cylinder drives the tapered portion to move towards the sliding arm, causing it to engage in the variable diameter hole of the pin. The tapered portion compresses the hole wall, increasing the outer diameter of the pin and causing the pin's periphery to abut against the inner wall of the sleeve. This allows the bellows to bend around the pin's axial direction. When the cylinder drives the tapered portion to move in the opposite direction, the compressive force on the hole wall disappears, allowing the pin to recover its deformation and reducing its outer diameter. This creates a gap between the pin and the inner wall of the sleeve. As the bellows bends around the two pins, the gap between the other two pins and the inner wall of the sleeve reduces the shear force on them during the bellows' bending deformation. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0022] Figure 1 This is a three-dimensional structural schematic diagram of a hinged bellows expansion joint with vibration fatigue resistance characteristics according to the present invention.

[0023] Figure 2 for Figure 1 A diagram illustrating the positional relationship from another perspective;

[0024] Figure 3 for Figure 2 A schematic diagram showing the positional relationship of the middle section after it has been cut open;

[0025] Figure 4 for Figure 1 Schematic diagram of the explosive decomposition of the medium structure;

[0026] Figure 5 for Figure 4 Enlarged schematic diagram of the local structure at point A:

[0027] Figure 6 This is a schematic diagram showing the positional relationship between the fixed arm, sliding arm, and cylinder after assembly in this invention:

[0028] Figure 7 for Figure 6 Schematic diagram showing the positional relationship of the middle section after it has been cut open:

[0029] Figure 8 for Figure 6 A diagram illustrating the positional relationship from another perspective;

[0030] Figure 9 for Figure 8 Schematic diagram of the explosive decomposition of the medium structure:

[0031] Figure 10 This is a cross-sectional view of the pin shaft in this invention.

[0032] Explanation of reference numerals in the attached drawings: 1. Bellows; 2. Fixed arm; 3. Sliding arm; 4. Cylinder; 5. Sleeve; 6. Sensing block; 7. Fixed ring; 8. Conical part; 9. Sleeve; 10. Extrusion ball; 11. Waist-shaped hole; 12. Limiting pin; 13. Inductive switch; 14. Pin; 15. Variable diameter slot; 16. Elastic element; 17. Conical part; 18. Variable diameter hole. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] This invention discloses a hinged bellows expansion joint with vibration fatigue resistance.

[0035] Example 1

[0036] Reference Figure 1-10This invention provides a hinged bellows expansion joint with vibration fatigue resistance as its first embodiment. This hinged bellows expansion joint with vibration fatigue resistance includes a bellows 1, with a corrugated section in the middle and flanges fixed to both ends. The two flanges are respectively connected to external pipelines. A sleeve 5 is fitted around the periphery of the bellows 1. The orthographic projection area of ​​the sleeve 5 covers the corrugated section of the bellows 1, and the length of the sleeve 5 is greater than the axial length of the corrugated section along the bellows 1. Furthermore, the inner diameter of the sleeve 5 is greater than... The outer diameter of the bellows 1 allows for a large gap between the sleeve 5 and the bellows 1. Two support arms are welded to each of the two axial ends of the bellows 1. The two support arms at each end of the bellows 1 are symmetrically arranged along the axial direction of the bellows 1. A fixed arm 2 extending towards the corrugated part of the bellows 1 is horizontally welded to the support arm. A sliding cavity is opened at the end of the fixed arm 2 facing the corrugated part. The longitudinal section of the sliding cavity is rectangular. A sliding arm 3 slides through the sliding cavity. There are four fixed arms 2, which are arranged in pairs at both ends of the bellows 1.

[0037] A retaining ring 7 is coaxially fixed to both ends of the sleeve 5. A conical portion 8 is integrally formed and fixed to the retaining ring 7. The outer diameter of the conical portion 8 increases sequentially away from the center of the bellows 1. Multiple notches are formed on the edge of the conical portion 8. A compression ball 10 is rotatably embedded at the smallest end of the outer diameter of the conical portion 8. The compression ball 10 rolls in contact with the periphery of the bellows 1. Furthermore, the notches are arranged in an array along the axial direction of the conical portion 8, dividing the conical portion 8 into multiple elastically deformable segments. The compression balls 10 are correspondingly rotatably embedded in the elastic segments, thus ensuring that the compression force exerted on the bellows 1 by the multiple elastic segments is uniform. An elastic element 16 is horizontally installed in the sliding cavity of the fixed arm 2. Specifically, the elastic element 16 can be set as a spring. One end of the spring elastically abuts against the end of the sliding arm 3, and the other end of the elastic element 16 elastically abuts against the end of the sliding arm 3, so that the elastic element 16 imparts potential energy to the sliding arm 3 to move in the direction of the corrugated part of the bellows 1. One end of the sliding arm 3 that passes through the sliding cavity is fixedly connected to a limiting pin 12. The fixed arm 2 has an oblong hole 11 for the limiting pin 12 to be inserted. The limiting pin 12 slides in the oblong hole 11, thereby limiting the sliding of the sliding arm 3 in the sliding cavity.

[0038] A protrusion is fixed to the wall of sleeve 5, and a bearing is installed on the protrusion. A sleeve 9 is fixedly installed on the inner ring of the bearing. A pin 14 is fixedly installed at the end of sliding arm 3 away from fixed arm 2. In its natural state, the outer diameter of pin 14 decreases sequentially in the direction away from sliding arm 3. Pin 14 is inserted into sleeve 9. A variable diameter hole 18 is coaxially opened at the end of pin 14 away from sliding arm 3. In its natural state, the diameter of variable diameter hole 18 increases sequentially in the direction away from sliding arm 3. The periphery of pin 14 is along its... Multiple variable diameter slots 15 are arranged in an axial array. By setting the variable diameter slots 15, the pin 14 can undergo elastic contraction deformation when subjected to extrusion force along its radial inner side. In addition, when the pin 14 is subjected to extrusion force along its radial outer side, the pin 14 will undergo elastic expansion deformation, causing the pin 14 to be stretched open. This makes the outer diameter of the pin 14 consistent with the inner diameter of the sleeve 9, so that the periphery of the pin 14 abuts against the inner wall of the sleeve 9. This allows the bellows 1 to bend around the axial direction of the pin 14.

[0039] A cylinder 4 is mounted on the sliding arm 3. The cylinder rod of the cylinder 4 slides through the pin 14 and is fixedly connected to a tapered portion 17. The outer diameter of the tapered portion 17 increases sequentially in the direction away from the sliding arm 3. As the cylinder rod of the cylinder 4 shortens, it drives the tapered portion 17 to move towards the sliding arm 3, causing the tapered portion 17 to engage in the variable diameter hole 18 of the pin 14. The tapered portion 17 compresses the wall of the variable diameter hole 18, increasing the outer diameter of the pin 14 and causing the periphery of the pin 14 to abut against the inner wall of the sleeve 9. This allows the bellows 1 to bend and deform around the axial direction of the pin 14. When the cylinder 4 drives the tapered portion 17... The tapered part 17 moves in the opposite direction, causing the extrusion force of the tapered part 17 on the wall of the variable diameter hole 18 to disappear, thereby causing the pin 14 to recover its own deformation and reducing the outer diameter of the pin 14. This results in a gap between the pin 14 and the inner wall of the sleeve 9. When the bellows 1 bends and deforms axially around the two pins 14, the other two pins 14 have a gap with the inner wall of the sleeve 9, thus reducing the shear force on the other two pins 14 when the bellows 1 bends and deforms. In addition, the sleeve 5 wall is fixed with a sensing block 6, and the sliding arm 3 is equipped with a sensing switch 13. The sensing switch 13 works in conjunction with the sensing block 6.

[0040] The working principle of this embodiment:

[0041] When the bellows 1 undergoes angular displacement, the location of the bending deformation may not be on the plane formed by the four pins 14, or the bending deformation location may be far from the pins 14. In this case, the bellows 1 will bend, causing the axes at both ends of the bellows 1 to change from a parallel state to an angled state. At this time, the compression balls 10 at both ends of the sleeve 5 will be subjected to the thrust of the bellows 1 during bending deformation, causing the compression balls 10 to roll on the bellows 1. Figure 1As shown, if the bending deformation position of the corrugated part of the bellows 1 is closer to the left side of the bellows 1, the bending amplitude of the right side of the bellows 1 is larger than that of the left side. The right wall of the bellows 1 will generate a thrust along the axial direction of the bellows 1 on the extrusion ball 10 located on the right side of the bellows 1. This causes the extrusion ball 10 to drive the cone 8 to move towards the left side of the bellows 1. In addition, the cone 8 moves towards the left side of the bellows 1 through the sliding arm 3 sliding in the sliding cavity of the fixed arm 2. When the cone 8 moves, it can drive the pin 14 to move towards the left side of the bellows 1. This makes the plane of the four pins 14 close to the bending deformation position of the bellows 1. In this way, the shear wear on the pins 14 is small when the bellows 1 is bent and deformed.

[0042] Furthermore, when the sliding arm 3 slides within the sliding cavity, it compresses the elastic element 16, causing the elastic element 16 to accumulate elastic potential energy. After the bending deformation force on the bellows 1 disappears, the elastic potential energy accumulated in the elastic element 16 is released, allowing the sleeve 5 to move back to its initial state on the bellows 1. Additionally, as... Figure 1 As shown, if the bellows 1 is bent and deformed around the axial direction of the two upper and lower pins 14, since the bending deformation position of the bellows 1 may not be in the plane of the axial direction of the pins 14, the other two pins 14 (the two transverse pins 14) will also be subjected to shear force when the bellows 1 is bent. At this time, the two vertical sliding arms 3 will swing with the right end of the bellows 1, thereby causing the inductive switches 13 on the two vertical sliding arms 3 to move away from the inductive block 6, causing the inductive signal generated by the inductive switches 13 to disappear. At this time, the external controller will control the two vertical cylinders 4 to start, causing the cylinder rods of the two cylinders 4 to shorten, thereby causing the tapered part 17 to be inserted into the variable diameter hole 18 and exert a squeezing force on the hole wall of the variable diameter hole 18, causing the pins to... The shaft 14 undergoes elastic expansion deformation, causing the periphery of the pin 14 to abut against the inner wall of the sleeve 9. At this time, the bellows 1 will rotate around the axial direction of the two pins 14, while the cylinder rods of the other two horizontal cylinders 4 are in an extended state. This results in a smaller pressure on the bore wall of the variable diameter hole 18 by the two tapered parts 17, causing the two pins 14 to undergo elastic contraction deformation. This results in a certain gap between the shaft edge of the two pins 14 and the inner wall of the sleeve 9. Through this gap, the two horizontal pins 14 have a certain degree of swing space, thereby reducing the shear wear on the pins 14. In addition, by setting the elastic element 16 and the tapered part 17, the expansion joint has certain anti-vibration fatigue characteristics when vibration occurs.

[0043] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A hinge-type bellows expansion joint having anti-vibration fatigue characteristics, comprising a bellows (1), characterized in that, Also include: Sleeve (5), sleeve in the circumference of the bellows (1), and the sleeve (5) inner diameter is greater than the outer diameter of the bellows (1); Floating unit, provided in the sleeve (5) and used to drive the sleeve (5) to move around the bellows (1) when the bellows (1) is bent and deformed; Fixed arm (2), provided with four and installed in the two ends of the bellows (1) in pairs, respectively, the fixed arm (2) is provided with a telescopic unit towards the one end of the bellows (1) center side, the telescopic unit is provided with a pin shaft (14) away from the one end of the fixed arm (2), the sleeve (5) wall surface is fixedly connected with the protruding part, the sleeve (9) is rotatably connected with the protruding part, the pin shaft (14) is slidably arranged in the sleeve (9), four protruding parts are arrayed along the axial direction of the sleeve (5) and are fixedly connected with the circumference of the sleeve (5); The floating unit includes a fixed ring (7) coaxially fixed to the axial ends of the sleeve (5), the fixed ring (7) is integrally connected with a tapered portion (8), the outer diameter of the tapered portion (8) increases gradually away from the center side of the bellows (1), a plurality of notch grooves are arranged on the tapered edge of the tapered portion (8), the outer diameter of the smallest end of the tapered portion (8) is rotatably embedded with an extrusion ball (10), and the extrusion ball (10) is in rolling contact with the circumference of the bellows (1); The telescopic unit includes a sliding arm (3) slidably arranged in the sliding cavity of the fixed arm (2); The pin shaft (14) is provided with a plurality of variable diameter slots (15) around the circumference, a variable diameter hole (18) is coaxially arranged at the end of the pin shaft (14) away from the sliding arm (3), the variable diameter slots (15) are in communication with the variable diameter hole (18), the sliding arm (3) is provided with an expansion unit for expanding the pin shaft (14), so that the pin shaft (14) is expanded, and the circumference of the pin shaft (14) is in close contact with the inner hole of the sleeve (9); The expansion unit includes a gas cylinder (4) mounted on the sliding arm (3), the cylinder rod of the gas cylinder (4) penetrates the pin shaft (14) and is fixedly connected with a tapered portion (17), and the outer diameter of the tapered portion (17) increases gradually away from the sliding arm (3).

2. The hinge-type bellows expansion joint having anti-vibration fatigue characteristics according to claim 1, characterized by, The notch grooves are arranged in the axial direction of the tapered portion (8).

3. The hinge-type bellows expansion joint having anti-vibration fatigue characteristics according to claim 1, characterized by, The pin shaft (14) is mounted on the sliding arm (3), the sliding cavity is provided with an elastic member (16), and the elastic member (16) gives the sliding arm (3) potential energy in the direction of the center side of the bellows (1).

4. The hinge-type bellows expansion joint having anti-vibration fatigue characteristics according to claim 3, characterized by, The end of the sliding arm (3) penetrating into the sliding cavity is fixedly connected with a limiting pin (12), and the fixed arm (2) is provided with a waist-shaped hole (11) for inserting the limiting pin (12).

5. The hinge-type bellows expansion joint having anti-vibration fatigue characteristics according to claim 3, characterized by, The elastic member (16) is a spring mounted in the sliding cavity, and the spring elastically abuts against the sliding arm (3).

6. The hinge-type bellows expansion joint having anti-vibration fatigue characteristics according to claim 3, characterized by, The longitudinal section of the sliding arm (3) is rectangular.

7. The hinge-type bellows expansion joint having anti-vibration fatigue characteristics according to claim 1, characterized by, The sleeve (5) wall surface is fixedly connected with a sensing block (6), the sliding arm (3) is provided with a sensing switch (13), and the sensing switch (13) is used in cooperation with the sensing block (6).

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