A combined labyrinth seal pipe expansion joint

Abstract

This invention relates to the field of pipeline connection and sealing technology, and discloses a combined labyrinth-type sealing pipeline expansion joint, comprising: an annular mounting groove at the end of a main pipe; one end of a limiting short pipe embedded in the main pipe; a labyrinth sealing assembly disposed between the main pipe and the outer wall of the limiting short pipe; a sealing ring disposed in the annular mounting groove; a clamping mechanism abutting against the sealing ring; a first mounting ring on the main pipe, the first mounting ring having multiple threaded holes; the clamping mechanism including a clamping ring fitted onto the limiting short pipe, a clamping ring on the clamping ring abutting against the sealing ring, and multiple first through holes on the clamping ring; a lead screw passing through the first through holes and threadedly connected to the threaded hole corresponding to the first through hole, and a sealing nut threadedly connected to the lead screw; this sealing pipeline expansion joint has a reasonable and reliable structure, effectively solving the fundamental problems of weak defense, easy instantaneous failure, and leakage driven by the kinetic energy of the medium in traditional single-point sealing, thus significantly improving the sealing effect.

Description

Technical Field

[0001] This invention relates to the field of pipeline connection and sealing technology, and in particular to a combined labyrinth-type sealing pipeline expansion joint. Background Technology

[0002] Expansion joints play an irreplaceable role in pipeline connections in municipal water supply, drainage, large-scale water diversion projects, power, and chemical industries. The key to an expansion joint is its sealing performance, which compensates for the expansion and contraction of pipelines due to thermal expansion and contraction, and provides deflection compensation within a certain range. In recent years, with social development and technological progress, the number of large-scale water transmission pipeline and municipal pipe network replacement projects has been increasing, and the requirements for the stable operation of the pipe network are also becoming more stringent. As a critical component of the pipeline system, the sealing performance of expansion joints directly affects the safety and efficiency of the system.

[0003] Currently, expansion joints based on the GB12465 standard frequently leak under high pressure and long-term service conditions. The root cause lies in the weak sealing system: relying solely on rubber sealing rings to form a single-point defense, once the sealing rings fail due to material aging, permanent compression deformation, or mechanical damage, the system immediately loses its sealing ability. More seriously, the sealing components are completely exposed, lacking ultraviolet shielding, and environmental factors such as sand, rain, snow, and sunlight directly accelerate the cracking and hardening of the rubber, further shortening the sealing life. Summary of the Invention

[0004] This invention proposes a combined labyrinth-type sealing pipe expansion joint to address the shortcomings of the prior art. The sealing pipe expansion joint has a reasonable and reliable structure, effectively solving the fundamental problems of weak traditional single-point sealing defense, easy instantaneous failure, and leakage driven by the kinetic energy of the medium, thus significantly improving the sealing effect.

[0005] The technical solution of this invention is: a combined labyrinth-type sealed pipe expansion joint, comprising: a main pipe, a limiting short pipe, a labyrinth sealing assembly, a second sealing ring, and a pressing mechanism. The main pipe has an annular mounting groove at its end, open to the side facing the inner cavity of the main pipe. One end of the limiting short pipe is embedded into the main pipe. The labyrinth sealing assembly includes multiple first sealing rings, which are sequentially arranged between the main pipe and the limiting short pipe along the length of the limiting short pipe. The second sealing ring is embedded in the annular mounting groove. The pressing mechanism is fitted onto the limiting short pipe and abuts against the second sealing ring to press it, so that the second sealing ring fits against the outer wall of the limiting short pipe, achieving a gap seal between the main pipe and the limiting short pipe.

[0006] In at least one embodiment of the present invention, the inner wall of the main tube and the outer wall of the limiting short tube are provided with a plurality of corresponding channels along the length direction, and the plurality of first sealing rings are respectively located in each corresponding channel.

[0007] In at least one embodiment of the present invention, a first mounting ring is provided near the end of the main tube, and the first mounting ring is provided with a plurality of threaded holes. The clamping mechanism includes a clamping ring and a plurality of screw rods. The clamping ring is fitted onto the limiting short tube, and the clamping ring is provided with a clamping ring that abuts against the second sealing ring. The clamping ring is provided with a plurality of first through holes that correspond one-to-one with the threaded holes. The plurality of screw rods pass through the first through holes and are threadedly connected to the threaded holes corresponding to the first through holes. A sealing nut is threadedly connected to the side of the clamping ring on each screw rod away from the first mounting ring.

[0008] In at least one embodiment of the present invention, the limiting short tube is provided with a second mounting ring, the second mounting ring is provided with a plurality of second through holes corresponding to the first through hole, the lead screw passes through the second through hole, and a limiting lock nut is threadedly connected to the side of the second mounting ring on the lead screw away from the clamping ring.

[0009] In at least one embodiment of the present invention, a dustproof pressure ring is provided on the outer side of the second sealing ring in the annular mounting groove, and the pressing ring abuts against the dustproof pressure ring.

[0010] In at least one embodiment of the present invention, the cross-section of the annular mounting groove is rectangular, and the cross-section of the second sealing ring is X-shaped.

[0011] In at least one embodiment of the present invention, the cross-sections of the multiple channels on the inner wall of the main tube and the outer wall of the limiting short tube are all arc-shaped, the spacing between each channel is equal, the cross-section of the first sealing ring is circular, and the outer wall of the first sealing ring is in contact with the outer wall of the channel.

[0012] In at least one embodiment of the present invention, the number of groove pairs on the inner wall of the main tube and the outer wall of the limiting short tube is greater than the number of the first sealing rings. When the pipeline expands or contracts due to temperature changes or external loads, multiple first sealing rings are embedded into different grooves as the limiting short tube and the main tube are displaced relative to each other, so as to maintain the gap seal between the limiting short tube and the main tube.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention, through a labyrinth sealing assembly consisting of multiple first sealing rings between the main pipe and the limiting short pipe, differs from the existing technology's "weak single-point sealing defense line, prone to instantaneous failure." Multiple first sealing rings multiply the complexity and effective length of the leakage path, forming a three-dimensional defense line. The eddies and turbulence generated by the fluid along the leakage path efficiently dissipate the leakage fluid pressure, significantly improving dynamic blocking efficiency and markedly reducing the leakage rate. Furthermore, this invention incorporates an annular mounting groove with a second sealing ring. Under the action of the clamping mechanism, the second sealing ring deforms and fits against the outer wall of the limiting short pipe, achieving a gap seal between the main pipe and the limiting short pipe. Compared to the existing technology where the sealing part is completely exposed, leading to accelerated rubber aging due to environmental factors, the second sealing ring prevents external impurities from entering the sealing surface, blocks dust and moisture, protects the sealing surface from contamination and corrosion, and reduces maintenance costs, extending pipeline service life. This comprehensive benefit achieves a balance between high performance and cost control, realizing a unity of sealing performance and economy.

[0014] 2. This invention provides grooves for installing the first sealing ring on the inner wall of the main pipe and the outer wall of the limiting short pipe, which can fully guarantee the gap seal by cooperating with the first sealing ring. Furthermore, addressing the problem in traditional structures where the sealing ring is prone to rolling misalignment with pipe expansion and contraction, resulting in seal failure, this invention makes the number of grooves greater than the number of first sealing rings. When the pipe expands or contracts due to temperature changes or external loads, multiple first sealing rings are embedded into different grooves with the relative displacement of the limiting short pipe and the main pipe, thereby maintaining the gap seal.

[0015] 3. By setting a second sealing ring with an X-shaped cross-section, the present invention can form two sealing lips on the inner wall of the annular mounting groove and the outer wall of the limiting short tube after the second sealing ring is compressed by the clamping mechanism, so as to fully ensure the isolation effect against dust and moisture. At the same time, the setting of the dustproof pressure ring further improves the ability of each sealing component to cope with environmental factors such as dust, moisture and ultraviolet rays, and improves the service life of the entire mechanism. Attached Figure Description

[0016] Figure 1 This is a schematic cross-sectional view of the present invention; Figure 2 For the present invention Figure 1 Detailed structural diagram of point A in the middle.

[0017] Explanation of reference numerals in the attached figures: 1. Main tube; 11. Annular mounting groove; 12. First mounting ring; 2. Limiting short tube; 21. Second mounting ring; 22. Limiting locking nut; 3. First sealing ring; 4. Second sealing ring; 41. Dustproof pressure ring; 5. Pressing mechanism; 51. Pressing ring; 52. Screw; 53. Sealing nut. Detailed Implementation

[0018] The accompanying drawings in this invention are not strictly drawn to scale, and the specific dimensions and quantity of each structure can be determined according to actual needs. The drawings described in this invention are merely structural schematic diagrams.

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all, of the embodiments of the present invention. Based on the described 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.

[0020] Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "inner," "outer," "upper," "lower," "far," "near," "front," and "rear" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0021] Existing expansion joints based on the GB12465 standard frequently leak under high pressure and long-term service conditions. The root cause lies in the flimsy sealing system: relying on only one or two simple rubber sealing rings to form a single-point defense. Once the sealing rings fail due to material aging, permanent compression deformation, or mechanical damage, the system immediately loses its sealing ability. During installation and operation, the sealing rings are prone to rolling misalignment with the expansion and contraction of the pipeline, losing their sealing effectiveness. The overall sealing reliability is low and the lifespan is short. More seriously, the sealing parts are completely exposed, without dust covers or UV shielding. Environmental factors such as sand, rain, snow, and sunlight directly accelerate the cracking and hardening of the rubber, further shortening the sealing life.

[0022] Therefore, the combination of the above-mentioned triple defects of single-line defense, lack of protection, and susceptibility to misalignment leads to a persistently high on-site leakage rate and rising maintenance costs.

[0023] This invention employs a combined labyrinth sealing method: through a multi-stage sealing structure, it significantly improves the sealing effect of the expansion joint during compensating motion. The optimized sealing path design ensures that the internal fluid must pass through the labyrinth sealing surface to reach the joint, utilizing fluid mechanics principles to increase leakage resistance and fundamentally reduce the probability of leakage. This effectively solves the fundamental problems of traditional single-point seals—weak defenses, susceptibility to instantaneous failure, and leakage driven by the kinetic energy of the medium—resulting in a significantly improved sealing effect.

[0024] Combination Figures 1 to 2 As shown, a combined labyrinth-type sealed pipe expansion joint includes: The end of the main tube 1 is provided with an annular mounting groove 11, which is open to the side facing the inner cavity of the main tube 1; the annular mounting groove 11 is located on the end face of the main tube 1.

[0025] The limiting short tube 2 extends into the main tube 1; the limiting short tube 2 and the main tube 1 are fitted with a clearance.

[0026] The labyrinth sealing assembly includes multiple first sealing rings 3, which are sequentially arranged between the main body pipe 1 and the limiting short pipe 2 along the length direction of the limiting short pipe 2 to seal the gap between the main body pipe 1 and the limiting short pipe 2. The multiple first sealing rings 3 multiply the complexity and effective length of the leakage path, forming a three-dimensional defense line. The eddies and turbulence generated by the fluid in the leakage path between the multiple first sealing rings 3 enable the leakage fluid pressure to be efficiently dissipated, significantly improving the dynamic blocking efficiency and significantly reducing the leakage rate.

[0027] The second sealing ring 4 is embedded in the annular mounting groove 11, and the entire second sealing ring 4 is fitted onto the limiting short pipe 2; the clamping mechanism 5 is fitted onto the limiting short pipe 2, and the clamping mechanism 5 abuts against the second sealing ring 4 to clamp the second sealing ring 4 so that the second sealing ring 4 fits against the outer wall of the limiting short pipe 2, so as to achieve a gap seal between the main pipe 1 and the limiting short pipe 2 at the end; the second sealing ring 4 can prevent external impurities from entering the sealing surface, block dust and moisture, protect the sealing surface from pollution and corrosion, and reduce maintenance costs and extend the service life of the pipeline.

[0028] As an alternative embodiment, the inner wall of the main tube 1 and the outer wall of the limiting short tube 2 are provided with multiple corresponding channels along the length direction, and multiple first sealing rings 3 are respectively located in each corresponding channel; the corresponding cooperation of multiple channels and first sealing rings 3 can further improve the sealing effect of the first sealing rings 3.

[0029] As an alternative embodiment, the main tube 1 is provided with a first mounting ring 12 near its end. The first mounting ring 12 is provided with multiple threaded holes. The clamping mechanism 5 includes a clamping ring 51 and multiple screw rods 52. The clamping ring 51 is fitted onto the limiting short tube 2. The clamping ring 51 is provided with a clamping ring that abuts against the second sealing ring 4. The clamping ring 51 is provided with multiple first through holes that correspond one-to-one with the threaded holes. The multiple screw rods 52 pass through the first through holes and are threadedly connected to the threaded holes corresponding to the first through holes. A sealing nut 53 is threadedly connected to the side of the clamping ring 51 away from the first mounting ring 12 on each screw rod 52.

[0030] As an alternative embodiment, the limiting short tube 2 is provided with a second mounting ring 21, and the second mounting ring 21 is provided with a plurality of second through holes corresponding to the first through hole. The lead screw 52 passes through the second through hole, and the side of the second mounting ring 21 on the lead screw 52 away from the clamping ring 51 is threadedly connected to a limiting locking nut 22. In use, by rotating the limiting locking nut 22, the clamping ring 51 can be driven by the second mounting ring 21 to squeeze the second sealing ring 4 to achieve gap sealing.

[0031] As an alternative embodiment, a dustproof pressure ring 41 is provided on the outer side of the second sealing ring 4 inside the annular mounting groove 11, and the clamping ring abuts against the dustproof pressure ring 41; the dustproof pressure ring 41 can prevent external impurities from entering the sealing surface and extend the sealing life. As an alternative embodiment, the cross-section of the annular mounting groove 11 is rectangular, and the cross-section of the second sealing ring 4 is X-shaped. After being compressed by the clamping mechanism 5, the second sealing ring 4 can form two sealing lips on the inner wall of the annular mounting groove 11 and the outer wall of the limiting short tube 2, respectively, so as to fully ensure the isolation effect against dust and moisture. Specifically, the second sealing ring 4 is a wear-resistant and anti-aging polymer composite material, which further extends the service life.

[0032] As an alternative embodiment, the cross-sections of multiple channels on the inner wall of the main tube 1 and the outer wall of the limiting short tube 2 are all arc-shaped, and the spacing between each channel is equal. The cross-section of the first sealing ring 3 is circular, and the outer wall of the first sealing ring 3 fits against the outer wall of the channel, thereby improving the fit between the first sealing ring 3 and the gap between the main tube 1 and the limiting short tube 2 and improving the sealing effect.

[0033] As an alternative embodiment, addressing the problem that existing devices are prone to rolling misalignment of sealing rings during pipe expansion and contraction, resulting in loss of sealing performance, low overall sealing reliability, and short lifespan, the present invention features a greater number of groove pairs on the inner wall of the main pipe 1 and the outer wall of the limiting short pipe 2 than the number of first sealing rings 3. When the pipe expands or contracts due to temperature changes or external loads, multiple first sealing rings 3 are embedded into different grooves as the limiting short pipe 2 and the main pipe 1 are relatively displaced, thereby maintaining a tight seal between the limiting short pipe 2 and the main pipe 1.

[0034] The sealing pipe expansion joint proposed in this invention has a reasonable and reliable structure, which effectively solves the fundamental problems of weak traditional single-point sealing defense, easy instantaneous failure, and leakage driven by the kinetic energy of the medium, thus significantly improving the sealing effect.

[0035] 1. Significantly improved sealing effect: The combined labyrinthine multi-stage sealing structure multiplies the complexity and effective length of the leakage path, forming a three-dimensional defense line and overcoming the defect of traditional single-point seals being prone to instantaneous failure; the flow channels between multiple first sealing rings 3 enable the generated eddies and turbulence to efficiently dissipate the pressure of the leaking fluid, significantly improving the dynamic blocking efficiency and significantly reducing the leakage rate.

[0036] 2. Energy saving and emission reduction, and resource conservation: Reduced leakage directly reduces water waste and has a significant energy-saving effect; the service life of pipelines is extended, the replacement frequency is reduced, and resource consumption is reduced accordingly.

[0037] 3. Reduced maintenance costs: Improved sealing reliability reduces the number of repairs, resulting in lower overall maintenance costs.

[0038] 4. Balance between economy and efficiency: The joint structure is optimized based on fluid mechanics principles, which controls costs while ensuring high performance; the structure is compact and easy to operate, achieving a balance between sealing performance and economy.

[0039] The above embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit them. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions implemented in the present invention, and should all be covered within the protection scope of the present invention.

Claims

1. A combined labyrinth-type sealed pipe expansion joint, characterized in that, include: The main tube has an annular mounting groove at its end, which is open to the side facing the inner cavity of the main tube; A limiting short tube, one end of which is embedded into the main tube; The labyrinth sealing assembly includes multiple first sealing rings, which are sequentially arranged between the main body tube and the limiting short tube along the length direction of the limiting short tube. The second sealing ring is fitted into the annular mounting groove; A clamping mechanism is fitted onto the limiting short tube. The clamping mechanism abuts against the second sealing ring and is used to clamp the second sealing ring so that the second sealing ring fits against the outer wall of the limiting short tube, thereby achieving a gap seal between the main tube and the limiting short tube.

2. The combined labyrinth-type sealing pipe expansion joint as described in claim 1, characterized in that, The inner wall of the main tube and the outer wall of the limiting short tube are provided with multiple corresponding channels along the length direction, and multiple first sealing rings are respectively located in each corresponding channel.

3. The combined labyrinth-type sealing pipe expansion joint as described in claim 1, characterized in that, The main tube is provided with a first mounting ring near its end, and the first mounting ring has multiple threaded holes. The clamping mechanism includes: A clamping ring is fitted onto a limiting short tube. The clamping ring is provided with a clamping ring that abuts against the second sealing ring. The clamping ring is provided with a plurality of first through holes that correspond one-to-one with the threaded holes. Multiple lead screws pass through the first through hole and are threaded into threaded holes corresponding to the first through hole. A sealing nut is threaded onto the side of the clamping ring on each lead screw away from the first mounting ring.

4. The combined labyrinth-type sealing pipe expansion joint as described in claim 3, characterized in that, The limiting short tube is provided with a second mounting ring, and the second mounting ring is provided with a plurality of second through holes corresponding to the first through hole. The lead screw passes through the second through hole, and a limiting lock nut is threadedly connected to the side of the second mounting ring on the lead screw away from the clamping ring.

5. A combined labyrinth-type sealed pipe expansion joint as described in claim 3, characterized in that, A dustproof pressure ring is provided on the outer side of the second sealing ring in the annular mounting groove, and the clamping ring abuts against the dustproof pressure ring.

6. The combined labyrinth-type sealing pipe expansion joint as described in claim 1, characterized in that, The cross-section of the annular mounting groove is rectangular, and the cross-section of the second sealing ring is X-shaped.

7. A combined labyrinth-type sealed pipe expansion joint as described in claim 2, characterized in that, The cross-sections of the multiple channels on the inner wall of the main tube and the outer wall of the limiting short tube are all arc-shaped, and the spacing between each channel is equal. The cross-section of the first sealing ring is circular, and the outer wall of the first sealing ring fits against the outer wall of the channel.

8. A combined labyrinth-type sealing pipe expansion joint as described in claim 2, characterized in that, The number of groove pairs on the inner wall of the main pipe and the outer wall of the limiting short pipe is greater than the number of the first sealing rings. When the pipe expands or contracts due to temperature changes or external loads, multiple first sealing rings are embedded into different grooves as the limiting short pipe and the main pipe are displaced relative to each other, so as to maintain the gap seal between the limiting short pipe and the main pipe.

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