Hinge type corrugated pipe expansion joint with vibration fatigue resistance

Abstract

The invention discloses a hinge type corrugated pipe expansion joint with vibration fatigue resistance and relates to the technical field of expansion joints, the hinge type corrugated pipe expansion joint comprises a corrugated pipe, a sleeve, a floating unit and a fixed arm, a telescopic unit is arranged at the end, facing the center side of the corrugated pipe, of the fixed arm, a pin shaft is installed at the end, away from the fixed arm, of the telescopic unit, and a protruding part is fixedly connected to the wall face of the sleeve. The four protruding parts are fixedly connected to the periphery of the casing pipe in an array mode in the axial direction of the casing pipe, when the corrugated pipe is bent in the using process, the floating unit drives the casing pipe to move, the pin shaft can move towards the bending deformation position of the corrugated pipe, and therefore the corrugated pipe can be bent. The hinge pin is arranged on the sliding arm, the deviation between the plane where the axis of the hinge pin is located and the bending deformation position of the corrugated pipe is reduced, then shearing abrasion borne by the hinge pin is reduced, in addition, the telescopic unit is further arranged, when the corrugated pipe axially deviates, the telescopic unit can make the sliding arm deviate to a certain degree, and large shearing force in the axial direction of the corrugated pipe is prevented from being generated on the hinge pin.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of expansion joint, in particular to a hinge type bellows expansion joint with anti-vibration fatigue characteristics. BACKGROUND

[0002] Expansion joint refers to a flexible element that can effectively compensate for axial deformation. For example, the expansion joint welded on the fixed tube plate type heat exchanger shell has large axial flexibility and is easy to deform, which can compensate for the thermal expansion difference between the pipe and the shell due to different wall temperatures, reduce their axial load, thereby reducing the temperature difference stress of the pipe, tube plate and shell, and avoiding causing strength damage, instability damage and pipe pull-out damage. There are many types of expansion joints, commonly used are wave type, ring plate welding and clamping shell type structures, among which the wave type expansion joint is the most widely used, the ring plate welding expansion joint is only suitable for normal pressure or low pressure occasions, and the expansion joint is also called compensator or expansion joint. The expansion joint is composed of a bellows (a flexible element) which constitutes the working main body and accessories such as end pipes, supports, flanges and guide pipes. The expansion joint is a flexible structure arranged on the vessel shell or pipe to compensate for additional stress caused by temperature difference and mechanical vibration. The effective expansion and deformation of the bellows, the working main body, is used to absorb the size change of the pipeline, guide pipe, container and the like caused by thermal expansion and contraction, or to compensate for the axial, lateral and angular displacement of the pipeline, guide pipe, container and the like. It can also be used for noise reduction and vibration reduction, heat supply, to prevent deformation or damage of the pipeline due to thermal elongation or temperature stress when the pipeline is heated, and to compensate for the thermal elongation of the pipeline, thereby reducing the stress on the pipe wall and the force acting on the valve or support structure.

[0003] The hinge type expansion joint is a special type of bellows expansion joint specially used to absorb the angular displacement (angular deflection) of the pipeline system. When the pipeline system bends (angular displacement) due to thermal expansion and contraction, the hinge type expansion joint connected to the pipeline will rotate (deflect) around its pin shaft. The bellows adapt to this angular change by bending and deforming itself. The existing hinge type expansion joint is forced to rotate around the axial direction of the pin shaft, but in actual deformation, the bending deformation position of the bellows is not in the plane of the axial center of the pin shaft, which will cause the pin shaft to be subjected to a large shear force, thereby accelerating the wear of the pin shaft and affecting the service life of the expansion joint. SUMMARY

[0004] In view of the problems in the prior art described above, the present application is proposed. Therefore, the present application aims to provide a hinge type bellows expansion joint with anti-vibration fatigue characteristics, and the problem to be solved is that the existing hinge type expansion joint is obtained by forcibly rotating the bellows around the axis of the pin shaft, and in actual deformation, the bending deformation position of the bellows is not in the plane where the axis of the pin shaft is located, which will cause the pin shaft to bear a large shear force, thereby exacerbating the wear of the pin shaft and affecting the service life of the expansion joint.

[0005] In order to achieve the above-mentioned purpose, the present application provides the following technical scheme: a hinge type bellows expansion joint with anti-vibration fatigue characteristics, comprising a bellows, further comprising: a sleeve, sleeved on the periphery of the bellows, and the inner diameter of the sleeve is greater than the outer diameter of the bellows; a floating unit arranged on the sleeve and used to drive the sleeve to move around the periphery of the bellows when the bellows is bent and deformed; four fixed arms, each of which is installed on one end of the bellows in pairs, one end of each fixed arm towards the center of the bellows is provided with an extension unit, one end of the extension unit away from the fixed arm is provided with a pin shaft, the wall surface of the sleeve is fixedly connected with a protruding part, the protruding part is rotatably connected with a sleeve, the pin shaft is slidably arranged in the sleeve, and four protruding parts are arrayed on the periphery of the sleeve along the axial direction of the sleeve.

[0006] As a preferred scheme of the hinge type bellows expansion joint with anti-vibration fatigue characteristics, the floating unit comprises a fixed ring coaxially fixed on the axial ends of the sleeve, the fixed ring is integrally connected with a tapered part, the outer diameter of the tapered part gradually increases towards the direction away from the center of the bellows, a plurality of notched grooves are arranged on the tapered edge of the tapered part, the smallest end of the outer diameter of the tapered part is rotatably embedded with an extrusion ball, and the extrusion ball is in rolling contact with the periphery of the bellows.

[0007] As a preferred scheme of the hinge type bellows expansion joint with anti-vibration fatigue characteristics, the notched grooves are arranged in an array along the axial direction of the tapered part.

[0008] As a preferred scheme of the hinge type bellows expansion joint with anti-vibration fatigue characteristics, the extension unit comprises a sliding arm slidably arranged in a sliding cavity arranged on the fixed arm, the pin shaft is arranged on the sliding arm, an elastic member is arranged in the sliding cavity, and the elastic member gives the sliding arm a potential energy in the direction towards the center of the bellows.

[0009] As a preferred scheme of the hinge type bellows expansion joint with anti-vibration fatigue characteristics, one end of the sliding arm penetrating into the sliding cavity is fixedly connected with a limiting pin, and the fixed arm is provided with a waist-shaped hole for inserting the limiting pin.

[0010] As a preferred scheme of the hinge type bellows expansion joint with the anti-vibration fatigue property, the elastic member is a spring installed in the sliding cavity and elastically abuts against the sliding arm.

[0011] As a preferred scheme of the hinge type bellows expansion joint with the anti-vibration fatigue property, the sliding arm is in a rectangular shape in the longitudinal section.

[0012] As a preferred scheme of the hinge type bellows expansion joint with the anti-vibration fatigue property, the pin shaft is provided with a plurality of variable-diameter slits around the periphery, a variable-diameter hole coaxially formed at the end of the pin shaft away from the sliding arm, the variable-diameter slits are communicated with the variable-diameter hole, and the sliding arm is provided with an expansion unit for expanding the pin shaft, so that the pin shaft is expanded and abuts against the inner hole of the sleeve.

[0013] As a preferred scheme of the hinge type bellows expansion joint with the anti-vibration fatigue property, the expansion unit comprises a gas cylinder installed on the sliding arm, the cylinder rod of the gas cylinder penetrates the pin shaft and is fixedly connected with a tapered portion, and the outer diameter of the tapered portion gradually increases away from the sliding arm.

[0014] As a preferred scheme of the hinge type bellows expansion joint with the anti-vibration fatigue property, the sleeve wall is fixedly connected with a sensing block, the sliding arm is provided with a sensing switch, and the sensing switch is used in cooperation with the sensing block.

[0015] 1、The hinge type bellows expansion joint with the anti-vibration fatigue property, through the sleeve and the floating unit, 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 axis of the pin shaft and the bending deformation position of the bellows is reduced, and the shear wear of the pin shaft is reduced.

[0016] 2、The hinge type bellows expansion joint with the anti-vibration fatigue property, through the extrusion ball, the tapered portion and the fixing ring, when the bellows is bent, the bending deformation position of the bellows may deviate far from the pin shaft, so that the shear force on the pin shaft is large when the bellows is bent around the pin shaft, the axial directions of the two ends of the bellows are in an angle state when the bellows is bent, the extrusion ball rolls on the periphery of the bellows and drives the sleeve to move, so that the sleeve moves towards the bending deformation position of the bellows, the deviation between the pin shaft and the bending deformation position of the bellows is reduced, and the shear wear of the pin shaft is reduced at least to a certain extent.

[0017] 3. The application, by setting the taper part, the cylinder, moving the taper part to the direction of the sliding arm by the cylinder, making the taper part clamped into the variable diameter hole of the pin shaft, extruding the hole wall of the variable diameter hole by the taper part, making the outer diameter of the pin shaft increased, and making the pin shaft circumference abutting with the sleeve inner hole wall, further making the bellows can produce bending deformation around the axial direction of the pin shaft, when the cylinder drives the taper part to move reversely, making the extruding force of the taper part to the hole wall of the variable diameter hole disappeared, further making the pin shaft restore its deformation, and making the outer diameter of the pin shaft decreased, further making the pin shaft and the sleeve inner wall have a gap, so that when the bellows is bent and deformed around the axial direction of the two pin shafts, the other two pin shafts have a gap with the sleeve inner wall, further reducing the shearing force to the other two pin shafts when the bellows is bent and deformed. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description only show some embodiments of the present application, and other drawings can also be obtained by those skilled in the art according to these drawings.

[0019] Figure 1 Fig. 1 is a perspective view of a hinge type bellows expansion joint with anti-vibration fatigue characteristics in the present application; Figure 2 Fig. 2 is a schematic view of the position relationship of another perspective view in the present application; Figure 1 Fig. 3 is a schematic view of the position relationship of a part of structure after being cut open in the present application; Figure 3 Fig. 4 is a schematic view of the position relationship of another perspective view in the present application; Figure 2 Fig. 5 is a schematic view of the position relationship of a part of structure after being cut open in the present application; Figure 4 Fig. 6 is a schematic view of the position relationship of another perspective view in the present application; Figure 1 Fig. 7 is an exploded view of the structure in the present application; Figure 5 Fig. 8 is a schematic view of the position relationship of another perspective view in the present application; Figure 4 Fig. 9 is an enlarged view of the local structure at A in the present application; Figure 6 Fig. 10 is a schematic view of the position relationship of the fixed arm, the sliding arm and the cylinder after being assembled in the present application; Figure 7 Fig. 11 is a schematic view of the position relationship of another perspective view in the present application; Figure 6 Fig. 12 is a schematic view of the position relationship of a part of structure after being cut open in the present application; Figure 8 Fig. 13 is a schematic view of the position relationship of another perspective view in the present application; Figure 6 Fig. 14 is an exploded view of the structure in the present application; Figure 9 Fig. 15 is a schematic view of the position relationship of another perspective view in the present application; Figure 8 Fig. 16 is an exploded view of the structure in the present application; Figure 10 Fig. 17 is a sectional view of the pin shaft in the present application.

[0020] Explanation of reference signs: 1, bellows; 2, fixed arm; 3, sliding arm; 4, air cylinder; 5, sleeve; 6, induction block; 7, fixed ring; 8, tapered portion; 9, sleeve; 10, extrusion ball; 11, waist-shaped hole; 12, limit pin; 13, induction switch; 14, pin shaft; 15, radial slot; 16, elastic member; 17, tapered portion; 18, variable-diameter hole. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0022] The embodiments of the present application disclose a hinge type bellows expansion joint with anti-vibration fatigue characteristics.

[0023] Embodiment 1 Reference Figures 1-10 For the first embodiment of the present application, a hinge type bellows expansion joint with anti-vibration fatigue characteristics is provided, which comprises a bellows 1, the middle part of the bellows 1 is a corrugated part, flange parts are fixedly connected at both ends of the corrugated part, the two flange parts are connected with external pipelines respectively, a sleeve 5 is sleeved on the periphery of the bellows 1, the orthographic projection area of the sleeve 5 covers the corrugated part of the bellows 1, and the length dimension of the sleeve 5 is greater than the length dimension of the corrugated part along the axial direction of the bellows 1, in addition, the inner diameter dimension of the sleeve 5 is greater than the outer diameter dimension of the bellows 1, so that there is a large gap between the sleeve 5 and the bellows 1, two support arms are welded at each axial end 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, and a fixed arm 2 extending towards the corrugated part of the bellows 1 is horizontally welded on the support arm, a sliding cavity is formed 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 is slidably arranged in the sliding cavity, the number of the fixed arms 2 is four, and the fixed arms 2 are arranged in pairs at both ends of the bellows 1; The sleeve 5 is coaxially fixed with the fixed ring 7 at both axial ends, the fixed ring 7 is integrally fixed with the taper part 8, the outer diameter of the taper part 8 increases in turn towards the direction away from the center of the bellows 1, the taper edge of the taper part 8 is provided with a plurality of notch grooves, the taper part 8 is rotatably embedded with the extrusion ball 10 at the end with the smallest outer diameter, the extrusion ball 10 rolls in contact with the peripheral edge of the bellows 1, in addition, the notch grooves are arranged in the axial direction of the taper part 8, the notch grooves divide the taper part 8 into a plurality of elastically deformable elastic petals, the extrusion ball 10 is correspondingly rotatably embedded on the elastic petals, so that the extrusion force of the plurality of elastic petals on the bellows 1 is uniform, the elastic member 16 is horizontally installed in the sliding cavity of the fixed arm 2, specifically, the elastic member 16 can be a spring, the elastic force direction of the spring elastically abuts against the end of the sliding arm 3, the elastic force direction of the elastic member 16 elastically abuts against the end of the sliding arm 3, so that the elastic member 16 gives the sliding arm 3 a potential energy to move towards the corrugated part of the bellows 1, the sliding arm 3 is fixed with the limit pin 12 at the end penetrating into the sliding cavity, the fixed arm 2 is provided with the waist-shaped hole 11 for the insertion of the limit pin 12, the limit pin 12 slides in the waist-shaped hole 11, thereby limiting the sliding of the sliding arm 3 in the sliding cavity; The wall surface of the sleeve 5 is fixed with a protruding part, the bearing is installed on the protruding part, the inner ring of the bearing is fixedly installed with the sleeve 9, the pin shaft 14 is fixedly installed at the end of the sliding arm 3 away from the fixed arm 2, in the natural state, the outer diameter size of the pin shaft 14 decreases in turn towards the direction away from the sliding arm 3, the pin shaft 14 is inserted into the sleeve 9, the end of the pin shaft 14 away from the sliding arm 3 is coaxially provided with the variable-diameter hole 18, in the natural state, the hole diameter size of the variable-diameter hole 18 increases in turn towards the direction away from the sliding arm 3, a plurality of variable-diameter slots 15 are arranged in the axial direction of the pin shaft 14, by arranging the variable-diameter slots 15, when the pin shaft 14 is subjected to the extrusion force along the radial inner side, the pin shaft 14 can elastically contract and deform, in addition, when the pin shaft 14 is subjected to the extrusion force along the radial outer side, the pin shaft 14 will elastically expand and deform, so that the pin shaft 14 is expanded, and then the outer diameter size of the pin shaft 14 is consistent with the inner diameter size of the sleeve 9, so that the peripheral edge of the pin shaft 14 abuts against the inner hole wall of the sleeve 9, so that the bellows 1 can be bent around the axial direction of the pin shaft 14; The cylinder 4 is installed on the sliding arm 3, the cylinder rod of the cylinder 4 penetrates the pin shaft 14 and is fixed with the conical part 17, the outer diameter size of the conical part 17 increases in turn in the direction away from the sliding arm 3, the cylinder rod of the cylinder 4 is shortened, and the conical part 17 is driven to move in the direction of the sliding arm 3, so that the conical part 17 is clamped into the variable diameter hole 18 of the pin shaft 14, the hole wall of the variable diameter hole 18 is extruded by the conical part 17, the outer diameter of the pin shaft 14 is increased, and the outer wall of the sleeve 9 is abutted by the outer wall of the pin shaft 14, so that the bellows 1 can be bent and deformed in the axial direction of the pin shaft 14, and when the cylinder 4 drives the conical part 17 to move reversely, the extrusion force of the conical part 17 to the hole wall of the variable diameter hole 18 disappears, so that the pin shaft 14 restores its deformation, the outer diameter of the pin shaft 14 is reduced, and the pin shaft 14 and the inner wall of the sleeve 9 have a gap, so that when the bellows 1 is bent and deformed in the axial direction of the two pin shafts 14, the other two pin shafts 14 have a gap with the inner wall of the sleeve 9, so that the shear force on the other two pin shafts 14 is reduced when the bellows 1 is bent and deformed, and in addition, the sensing block 6 is fixed on the wall of the sleeve 5, and the sensing switch 13 is installed on the sliding arm 3 and is used in cooperation with the sensing block 6.

[0024] The working principle of the embodiment is as follows: When the bellows 1 is angularly offset, the position of the bending deformation of the bellows 1 may not be on the plane formed by the four pin shafts 14, or the position of the bending deformation is far away from the pin shaft 14, at this time, the bellows 1 will be bent and deformed, so that the two ends of the bellows 1 are changed from the parallel state to the angle state, at this time, the extrusion balls 10 at the two ends of the sleeve 5 will be subjected to the thrust force when the bellows 1 is bent and deformed, so that the extrusion balls 10 roll on the bellows 1, as shown in Figure 1 If the position of the bending deformation of the bellows 1 is relatively close to the left side of the bellows 1, at this time, the bending amplitude of the right side of the bellows 1 is relatively large, the right side wall of the bellows 1 will generate the thrust force in the axial direction of the bellows 1 on the extrusion ball 10 located on the right side of the bellows 1, so that the extrusion ball 10 drives the conical part 8 to move in the direction of the left side of the bellows 1, and in turn drives the conical part 8 to move in the direction of the left side of the bellows 1, and in addition, the sliding arm 3 slides in the sliding cavity of the fixed arm 2, so that when the conical part 8 moves, the pin shaft 14 can be driven to move in the direction of the left side of the bellows 1, so that the plane where the four pin shafts 14 are located can be close to the position of the bending deformation of the bellows 1, so that the shear wear of the pin shaft 14 is small when the bellows 1 is bent and deformed; In addition, when the sliding arm 3 slides in the sliding cavity, the elastic member 16 will be compressed, so that the elastic member 16 accumulates the elastic potential energy, and when the bending deformation force of the bellows 1 disappears, the elastic potential energy accumulated by the elastic member 16 is released, so that the sleeve 5 can move on the bellows 1 to the initial state, and in addition, as shown in Figure 1As shown, if the bellows 1 is bent and deformed around the axial direction of the two upper and lower pin shafts 14, since the bending and deforming position of the bellows 1 can not be in the plane of the axial direction of the pin shafts 14, the other two pin shafts 14 (the two pin shafts 14 in the horizontal direction) will also be subjected to shearing force when the bellows 1 is bent, at this time, the two sliding arms 3 in the vertical direction will swing with the right end of the bellows 1, and then the inductive switch 13 on the two sliding arms 3 in the vertical direction will move away from the inductive block 6, so that the inductive signal generated by the inductive switch 13 disappears, at this time, the external controller will control the two cylinders 4 in the vertical direction to start, so that the cylinder rods of the two cylinders 4 are shortened, and then the tapered portion 17 will be clamped into the variable diameter hole 18, and the hole wall of the variable diameter hole 18 is subjected to extrusion force, so that the pin shaft 14 is elastically expanded and deformed, and the circumference of the pin shaft 14 abuts tightly with the inner wall of the sleeve 9, at this time, the bellows 1 will rotate around the axial direction of the two pin shafts 14, and the cylinder rods of the other two cylinders 4 in the horizontal direction are in the elongated state, and then the extrusion force of the two tapered portions 17 on the hole wall of the variable diameter hole 18 is small, so that the two pin shafts 14 are in the elastic contraction deformation state, and then the axial edge of the two pin shafts 14 has a certain gap with the inner wall of the sleeve 9, through the gap, the two pin shafts 14 in the horizontal direction have a certain degree of swing space, and then the shearing wear of the pin shaft 14 is reduced, and in addition, through the setting of the elastic member 16 and the tapered portion 17, the expansion joint has a certain anti-vibration fatigue characteristic in the case of vibration.

[0025] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, not to limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. A hinged bellows expansion joint with vibration fatigue resistance, comprising a bellows (1), characterized in that, Also includes: A sleeve (5) is fitted around the corrugated pipe (1), and the inner diameter of the sleeve (5) is larger than the outer diameter of the corrugated pipe (1); A floating unit is provided on the sleeve (5) and is used to drive the sleeve (5) to move around the periphery of the bellows (1) when the bellows (1) is bent and deformed; Fixed arms (2) are provided, and are installed in pairs at both ends of the corrugated pipe (1). One end of the fixed arm (2) facing the center of the corrugated pipe (1) is provided with a telescopic unit. The end of the telescopic unit away from the fixed arm (2) is provided with a pin (14). The sleeve (5) is fixedly connected to the wall with a protrusion. The protrusion is rotatably connected to a sleeve (9). The pin (14) is slidably inserted into the sleeve (9). The four protrusions are arrayed along the axial direction of the sleeve (5) and fixedly connected to the periphery of the sleeve (5).

2. The hinged bellows expansion joint with vibration fatigue resistance as described in claim 1, characterized in that, The floating unit includes a fixed ring (7) coaxially fixed to both ends of the sleeve (5). The fixed ring (7) is integrally formed and fixed with a cone (8). The outer diameter of the cone (8) increases sequentially in the direction away from the center of the bellows (1). The cone (8) has multiple notches and grooves on its edge. The smallest end of the outer diameter of the cone (8) is rotatably fitted with a squeeze ball (10). The squeeze ball (10) rolls and contacts the periphery of the bellows (1).

3. The hinged bellows expansion joint with vibration fatigue resistance as described in claim 2, characterized in that, The notched grooves are arranged in an array along the axial direction of the cone (8).

4. The hinged bellows expansion joint with vibration fatigue resistance as described in claim 1, characterized in that, The telescopic unit includes a sliding arm (3) that slides through a sliding cavity opened in the fixed arm (2), a pin (14) is installed on the sliding arm (3), and an elastic element (16) is installed in the sliding cavity. The elastic element (16) gives the sliding arm (3) the potential energy to move toward the center side of the bellows (1).

5. The hinged bellows expansion joint with vibration fatigue resistance as described in claim 4, characterized in that, One end of the sliding arm (3) that passes through the sliding cavity is fixedly connected to a limiting pin (12), and the fixed arm (2) has an oblong hole (11) for the limiting pin (12) to be inserted.

6. The hinged bellows expansion joint with vibration fatigue resistance as described in claim 4, characterized in that, The elastic element (16) is a spring installed in the sliding cavity, and the spring elastically abuts against the sliding arm (3).

7. The hinged bellows expansion joint with vibration fatigue resistance as described in claim 4, characterized in that, The longitudinal section of the sliding arm (3) is rectangular.

8. The hinged bellows expansion joint with vibration fatigue resistance as described in claim 1, characterized in that, The pin (14) has multiple diameter-changing slots (15) around its periphery. The end of the pin (14) away from the sliding arm (3) has a diameter-changing hole (18) coaxially. The diameter-changing slots (15) are connected to the diameter-changing hole (18). The sliding arm (3) is provided with an expansion unit for expanding the pin (14) so ​​that after the pin (14) is expanded, the periphery of the pin (14) abuts against the inner hole of the sleeve (9).

9. The hinged bellows expansion joint with vibration fatigue resistance as described in claim 8, characterized in that, The expansion unit includes a cylinder (4) 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 part (17). The outer diameter of the tapered part (17) increases sequentially in the direction away from the sliding arm (3).

10. The hinged bellows expansion joint with vibration fatigue resistance according to claim 8, characterized in that, The sleeve (5) has a sensing block (6) fixed to its wall, and the sliding arm (3) is equipped with a sensing switch (13). The sensing switch (13) works in conjunction with the sensing block (6).

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