A composite sealing structure and a rotary compensator using the same

Abstract

The present application relates to a composite sealing structure and a rotary compensator using the same. The composite sealing structure is arranged between an annular inner boss on the inner surface of an outer sleeve and one end of a packing flange extending into the outer sleeve, and includes a sealing assembly and a sliding extrusion ring; the sliding extrusion ring is located between the sealing assembly and the annular inner boss, and the sealing assembly includes N sealing rings and N minus one sealing ring, where N is a natural number greater than or equal to 2, and the aforementioned sealing rings and sealing rings are arranged alternately. The composite sealing structure described in the present application can effectively solve the problem that the seal of the existing rotary compensator is prone to oxidation, burning and wear due to the use of flexible graphite fillers, and long-term use will increase the probability of leakage of the compensator, thereby improving the sealing performance of the rotary compensator and extending its service life.

Description

Technical Field

[0001] The invention relates to a sealing structure, in particular to a composite sealing structure and a rotary compensator adopting the structure. Background Art

[0002] Compensation devices are generally required to be installed in pipelines in industries such as electricity, petroleum, chemical industry, and thermal power. Existing compensation devices usually include rotary compensators, bellows compensators, rotary compensators, spherical compensators, etc., which are used to compensate for the axial or radial displacement of the pipeline caused by thermal expansion and contraction. Since the medium transported by the pipeline generally has a certain temperature and pressure, there are higher requirements for the sealing performance of the compensator, especially when transporting high-temperature and high-pressure media, the requirements for the compensator are higher: not only must there be sufficient displacement compensation, but also good sealing performance and a long service life.

[0003] The existing rotary compensator is provided with a seal between the annular inner boss on the inner surface of the outer sleeve and the end of the packing flange extending into the outer sleeve. The seal usually adopts flexible graphite packing. Flexible graphite seal has the characteristics of high temperature resistance, good lubricity, small friction coefficient, no hardening, no volatility, no flow, non-toxicity, no pollution, and aging resistance. However, flexible graphite is easy to oxidize, burn and wear, and long-term use will increase the probability of compensator leakage. Summary of the invention

[0004] The technical problem to be solved by the present invention is that the seals of existing rotary compensators for pipelines use flexible graphite fillers, which will increase the probability of compensator leakage due to oxidation, burning and wear after long-term use. A composite sealing structure and a rotary compensator using the structure are provided to further improve the sealing performance of the rotary compensator.

[0005] The composite sealing structure of the present invention is arranged between the annular inner boss on the inner surface of the outer sleeve and one end of the packing flange extending into the outer sleeve, and includes a sealing assembly and a sliding extrusion ring; the sliding extrusion ring is located between the sealing assembly and the annular inner boss, and the sealing assembly includes N sealing rings and N minus one sealing ring, N is a natural number greater than or equal to 2, and the aforementioned sealing rings and sealing rings are arranged alternately.

[0006] The rotary compensator described in the present invention includes an inner tube, a connecting tube, an outer sleeve sleeved on the inner tube and a packing flange, one end of the packing flange extends into the outer sleeve, the packing flange and the outer sleeve are connected by fasteners, an annular outer boss is provided on the outer surface of the inner tube, and an annular inner boss is provided on the inner surface of the outer sleeve; it also includes a composite sealing structure, which is arranged between the annular inner boss and one end of the packing flange extending into the outer sleeve, and consists of a sealing assembly and a sliding extrusion ring; the sliding extrusion ring is located between the sealing assembly and the inner inner boss of the ring, and the sealing assembly includes N sealing rings and N minus one sealing ring, N is a natural number greater than or equal to 2, and the aforementioned sealing rings and sealing rings are arranged alternately.

[0007] In the sealing assembly, both side surfaces of the sealing ring are concave to form a cavity with a V-shaped cross section. The cross-sectional shape of the end of the packing flange extending into the outer sleeve and the cross-sectional shape of the end of the sliding extrusion ring adjacent to the sealing ring are both triangles adapted to the aforementioned V-shaped cavity. A diamond-shaped cavity is formed between two adjacent sealing rings, and the cross-sectional shape of the corresponding sealing ring is a diamond, with both ends respectively extending into the V-shaped cavity of the adjacent sealing ring.

[0008] The sealing ring is made of elastic material, such as rubber.

[0009] In order to prevent the sealing ring in the composite sealing structure from producing gaps due to normal wear after long-term use, thereby affecting the sealing performance of the rotary compensator, a spring flange is also provided on the outside of the packing flange, and axially arranged springs are evenly distributed along the same circumference between the spring flange and the packing flange. The spring flange, the packing flange and the outer sleeve are connected by the same fastener. When the sealing ring produces gaps due to normal wear after long-term use, the packing flange can be further extended into the outer sleeve under the action of the spring, thereby eliminating the gaps caused by normal wear of the sealing ring in the composite sealing structure after long-term use.

[0010] In order to further improve the sealing performance of the rotary compensator, a sealing filler is arranged between the sliding extrusion ring and the annular inner boss, thereby forming another sealing cavity.

[0011] In order to prevent the sealing packing from generating gaps due to normal wear during long-term use, thereby affecting the sealing performance of the entire rotary compensator, a packing filling device is provided at the position corresponding to the outer sleeve and the sealing packing, so as to realize online filling of the sealing packing.

[0012] In order to facilitate the relative rotation between the inner tube and the outer tube, a sliding member is provided in the cavity formed between the first annular inner boss and the annular outer boss, and the sliding member is a sliding ring or a ball.

[0013] Since both side surfaces of the sealing ring of the sealing assembly in the composite sealing structure adopted by the present invention are concave to form a cavity with a tapered cross-section, the cavity and the tapers on both sides of the diamond-shaped sealing ring cooperate with each other. After assembly, only relatively small force is needed to make the sealing ring fit and seal with the outer wall of the inner tube and the inner wall of the outer sleeve under the top pressure of the diamond-shaped sealing ring. This can effectively solve the problem that the main seal of the existing rotary compensator uses flexible graphite filler that is easily oxidized, burned and worn, and long-term use will increase the probability of compensator leakage. This can improve the sealing performance of the rotary compensator and extend its service life.

[0014] Furthermore, the present invention forms a double sealing cavity by arranging a sealing filler between the sliding extrusion ring and the annular inner boss, thereby enhancing the sealing performance of the rotary compensator.

[0015] In the case of setting up a double sealing chamber, the present invention can also add a sealing filler filling device at the position of the outer sleeve corresponding to the sealing filler. In this way, when the sealing filler's sealing performance is reduced due to oxidation, burning and wear due to long-term use, the sealing filler can be added inwardly through the filler filling device to ensure the sealing performance of the sealing filler. Moreover, with the filling of the sealing filler, when the pressure in the sealing chamber corresponding to the filler filling device gradually increases, the sliding extrusion ring tends to move toward the direction of the sealing assembly after being pressurized, further compressing the sealing assembly, thereby further improving the sealing performance of the rotary compensator. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the structure of Example 1 of the present invention.

[0017] Figure 2 for Figure 1 A section enlarged view.

[0018] Figure 3 This is a schematic diagram of the structure of Example 2 of the present invention.

[0019] Figure 4 for Figure 3 Enlarged cross-sectional view of part B.

[0020] Figure 5 This is a schematic diagram of the structure of Example 3 of the present invention.

[0021] Figure 1-Figure 5 Among them, 1 is an inner tube, 2 is a fastener, 3 is a packing flange, 4 is an outer sleeve, 5 is a sealing ring, 6 is a sealing ring, 7 is a packing filling device, 8 is a sealing packing, 9 is a sliding part, 10 is a connecting pipe, 11 is an annular inner boss, 12 is an annular outer boss, 13 is a spring flange, 14 is a spring, 15 is an extrusion sliding ring, and 16 is a limit block. DETAILED DESCRIPTION

[0022] Example 1

[0023] like Figure 1 As shown, this embodiment is a rotary compensator with a composite sealing structure, including an inner tube 1, a connecting tube 10, an outer sleeve 4 sleeved on the inner tube and a packing flange 3. The outer sleeve 4 and the connecting tube 10 are an integrated structure, and a limit block 16 is arranged in the connecting tube. One end of the packing flange 3 extends into the outer sleeve 4, and the packing flange 3 is connected to the outer sleeve 4 by a fastener 2. An annular inner boss 11 is arranged on the inner surface of the outer sleeve 4, and an annular outer boss 12 is arranged on the outer surface of the inner tube 1. A sliding member 9 is arranged in the cavity between the annular inner boss 11 and the annular outer boss 12 to facilitate the relative rotation of the inner tube 1 relative to the outer sleeve 4. In this embodiment, the sliding member 9 adopts a sliding ring, and a ball in the prior art can also be adopted.

[0024] See also Figure 1 , Figure 2 In the present invention, a composite sealing structure is arranged between the annular inner boss 11 and the end of the packing flange 3 extending into the outer sleeve 4, and the composite sealing structure is composed of a sealing assembly and a sliding extrusion ring 15. The sliding extrusion ring 15 is located between the sealing assembly and the annular inner boss 11, and the sealing assembly includes N sealing rings 6 and N minus one sealing ring 5, where N is a natural number greater than or equal to 2, and the aforementioned sealing rings 6 and sealing rings 5 ​​are arranged alternately, that is, there is a sealing ring between every two adjacent sealing rings. This embodiment has three sealing rings and two sealing rings.

[0025] In the sealing assembly, both side surfaces of the sealing ring 6 are concave to form a cavity with a V-shaped cross section. The cross-sectional shape of the end of the packing flange 3 extending into the outer sleeve 4 and the cross-sectional shape of the end of the sliding extrusion ring 15 adjacent to the sealing ring 6 are both triangles adapted to the aforementioned V-shaped cavity; a diamond-shaped cavity is formed between two adjacent sealing rings 6, and the corresponding sealing ring 5 has a diamond-shaped cross-sectional shape, with both ends respectively extending into the V-shaped cavity of the adjacent sealing ring 6.

[0026] In this embodiment, the sealing ring is made of fluororubber; it can also be made of other elastic materials. The sealing ring is made of stainless steel, and of course other metal materials can also be used.

[0027] The sealing principle of the composite sealing structure of the present invention is:

[0028] Since the sealing ring is made of elastic material and its two side surfaces are concave to form a cavity with a tapered cross-section, the cavity and the tapers on both sides of the diamond-shaped sealing ring cooperate with each other. After assembly, only relatively small force is required to make the sealing ring fit and seal with the outer wall of the inner tube and the inner wall of the outer sleeve under the top pressure of the diamond-shaped sealing ring.

[0029] When the rotary compensator is working, since the sealing ring of the composite sealing structure has a tapered structure on both sides, when the product is assembled, under the action of the fasteners, a clamping force may be applied to the composite sealing structure through the packing flange, and the diamond-shaped sealing ring directly squeezes the sealing ring to both sides, so that the sealing ring and the inner tube and outer tube can be tightly sealed with less force to achieve a sealing effect.

[0030] Example 2

[0031] like Figure 3 As shown, in order to further improve the sealing performance of the rotary compensator, in this embodiment, a sealing filler 8 is arranged between the sliding extrusion ring 15 and the annular inner boss to form another sealing cavity, thereby forming a double sealing cavity structure.

[0032] See also Figure 3 , Figure 4 In order to prevent the sealing packing 8 from generating gaps due to normal wear during long-term use, thereby affecting the sealing performance of the entire rotary compensator, a packing filling device 7 is provided at the position corresponding to the sealing packing 8 on the outer sleeve 4 in this embodiment. Specifically, 2-30 injection ports are evenly distributed along the same circumference at the position corresponding to the sealing packing on the outer sleeve 4, and the radial through hole built in each injection port is connected to the transverse hole of the waist. A screw plug is provided at the outer end of the radial through hole, and the screw plug installed in the transverse hole crosses the radial through hole to form a sealing packing filling device 7 of the valve structure. During the use of the rotary compensator, when the sealing packing in the first sealing cavity generates gaps due to normal wear during long-term use, thereby causing the sealing performance of the rotary compensator to decrease, the screw plug installed at the outer end of the injection port and the screw plug in the transverse hole can be removed online, and the sealing packing can be supplemented with a pressure gun facing the injection port. After the supplementation is completed, the screw plug in the transverse hole is first tightened, and then the pressure gun is pulled out, and then the screw plug is reinstalled at the outer end of the inlet. In this way, by supplementing the sealing packing online, the volume of the sealing packing in the sealing cavity is increased, thereby timely restoring the sealing performance of the rotary compensator.

[0033] The above-mentioned filler filling device is prior art.

[0034] In this embodiment, the sealing filler is made of flexible graphite; the sealing ring is made of fluororubber, and may also be made of other elastic materials; the sealing ring is made of stainless steel, and of course may also be made of other metal materials.

[0035] Example 3

[0036] like Figure 5As shown, in order to prevent the sealing ring in the composite sealing structure from generating gaps due to normal wear after long-term use, thereby affecting the sealing performance of the rotary compensator, this embodiment is provided with a spring flange 13 on the outside of the packing flange 3 on the basis of embodiment 1, and axially arranged springs 14 are evenly distributed along the same circumference between the spring flange 13 and the packing flange 3, and the spring flange 13, the packing flange 3 and the outer sleeve 4 are connected by the same fastener 2. The spring 14 is in a compressed state under normal working conditions. When the sealing ring 6 generates gaps due to normal wear after long-term use, the packing flange 3 can be further extended into the outer sleeve 4 under the elastic force of the spring 14, thereby eliminating the gaps generated by the normal wear of the sealing ring 6 in the composite sealing structure after long-term use, so that the diamond-shaped sealing ring 5 keeps squeezing the sealing ring 6, so that the sealing ring 6 continues to fit tightly with the inner tube 1 and the outer sleeve 4.

[0037] In this embodiment, the sealing filler is made of flexible graphite; the sealing ring is made of fluororubber, and may also be made of other elastic materials; the sealing ring is made of stainless steel, and of course may also be made of other metal materials.

Claims

1. A composite sealing structure, characterized in that The composite sealing structure is arranged between the annular inner boss on the inner surface of the outer sleeve and one end of the packing flange extending into the outer sleeve, and includes a sealing assembly and a sliding extrusion ring; the sliding extrusion ring is located between the sealing assembly and the annular inner boss, and the sealing assembly includes N sealing rings and N minus one sealing ring, where N is a natural number greater than or equal to 2, and the aforementioned sealing rings and sealing rings are arranged alternately; In the sealing assembly, both side surfaces of the sealing ring are concave to form a cavity with a V-shaped cross section. The cross-sectional shape of the end of the packing flange extending into the outer sleeve and the cross-sectional shape of the end of the sliding extrusion ring adjacent to the sealing ring are both triangles adapted to the aforementioned V-shaped cavity. A diamond-shaped cavity is formed between two adjacent sealing rings, and the cross-sectional shape of the corresponding sealing ring is a diamond, with both ends respectively extending into the V-shaped cavity of the adjacent sealing ring.

2. The composite sealing structure according to claim 1, characterized in that The sealing ring is made of elastic material.

3. A rotary compensator, characterized in that It comprises an inner tube, a connecting tube, an outer sleeve sleeved on the inner tube and a packing flange, one end of the packing flange extends into the outer sleeve, the packing flange and the outer sleeve are connected by a fastener, an annular outer boss is provided on the outer surface of the inner tube, an annular inner boss is provided on the inner surface of the outer sleeve, and a composite sealing structure is also included, the composite sealing structure is arranged between the annular inner boss and one end of the packing flange extending into the outer sleeve, and is composed of a sealing assembly and a sliding extrusion ring; the sliding extrusion ring is located between the sealing assembly and the annular inner boss, the sealing assembly comprises N sealing rings and N minus one sealing ring, N is a natural number greater than or equal to 2, and the aforementioned sealing rings and sealing rings are arranged alternately; In the sealing assembly, both side surfaces of the sealing ring are concave to form a cavity with a V-shaped cross section. The cross-sectional shape of the end of the packing flange extending into the outer sleeve and the cross-sectional shape of the end of the sliding extrusion ring adjacent to the sealing ring are both triangles adapted to the aforementioned V-shaped cavity. A diamond-shaped cavity is formed between two adjacent sealing rings, and the cross-sectional shape of the corresponding sealing ring is a diamond, with both ends respectively extending into the V-shaped cavity of the adjacent sealing ring.

4. The rotary compensator according to claim 3, characterized in that The sealing ring is made of elastic material.

5. The rotary compensator according to claim 3, characterized in that A spring flange is also arranged on the outer side of the packing flange. Axially arranged springs are evenly distributed along the same circumference between the spring flange and the packing flange. The spring flange, the packing flange and the outer sleeve are connected by the same fastener.

6. The rotary compensator according to claim 3, characterized in that A sealing filler is arranged between the sliding extrusion ring and the annular inner boss.

7. The rotary compensator according to claim 3, characterized in that A sealing filler filling device is provided at a position on the outer sleeve corresponding to the sealing filler.

8. The rotary compensator according to claim 3, characterized in that A sliding member is arranged between the inner annular boss and the outer annular boss.

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