Pressure balance mechanism and sealing unit

Abstract

The utility model provides a pressure balance mechanism and a sealing unit, and the pressure balance mechanism comprises a fixed part which is fixedly connected to the sealing unit; the multiple telescopic assemblies are sequentially connected in a sealed mode in the telescopic direction; in the telescopic direction, the telescopic assembly located at one end of the multiple telescopic assemblies is connected to the fixing piece in a sealed mode, and the telescopic assembly located at the other end is provided with a pressure bearing face. The pressure bearing face is used for bearing pressure in the sealing unit, and the multiple telescopic assemblies are used for stretching out and drawing back under the pressure effect so as to balance the pressure. According to the pressure balancing mechanism and the sealing unit, the liquid pressure in the sealing cavity can be balanced, the reliability is high, and the working stability of submarine equipment can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of pipeline fittings, and in particular to a pressure balancing mechanism and a sealing unit. Background Art

[0002] When submarine equipment is working on the seabed, it needs to be isolated from seawater to avoid seawater erosion or short circuit of the submarine equipment. When placing submarine equipment on the seabed, it is usually placed in a sealed cavity of a sealed unit to isolate the seawater. However, when the submarine equipment is working in a sealed unit, the air thermal resistance in the sealed cavity is large, and the heat generated by high-power devices is difficult to effectively transfer to the seawater, resulting in poor heat dissipation of the submarine equipment in the sealed unit.

[0003] In order to improve the heat dissipation effect of the submarine equipment in the sealed unit, the commonly used heat dissipation method is to fill the sealed cavity with insulating oil to achieve heat dissipation and insulation protection for the submarine equipment. However, the volume of the insulating oil will expand and contract with the change of the temperature of the submarine equipment, and the sealed cavity is in a sealed state, which causes the oil pressure of the insulating oil to change during the process of thermal expansion and contraction, affecting the normal operation of the submarine equipment in the sealed cavity. Utility Model Content

[0004] In order to solve the above problems, the present application provides a pressure balancing mechanism and a sealing unit, which can balance the liquid pressure in the sealing chamber, have high reliability, and can improve the working stability of the subsea equipment.

[0005] In order to achieve the above-mentioned purpose, the first aspect of the present application provides a pressure balancing mechanism, including: a fixing member, which is fixedly connected to a sealing unit; a plurality of telescopic components, which are sealed and connected in sequence along the telescopic direction; along the telescopic direction, the telescopic component located at one end of the plurality of telescopic components is sealed and connected to the fixing member, and the telescopic component located at the other end has a pressure-bearing surface; the pressure-bearing surface is used to bear the pressure inside the sealing unit, and the plurality of telescopic components are used to telescope under the action of pressure to balance the pressure.

[0006] In the pressure balancing mechanism provided in this embodiment, a plurality of relatively independent retractable components are arranged in a pressure balancing mechanism, and each retractable component can form a pressure balancing unit to realize the redundant design of the pressure balancing unit. After one of the retractable components is damaged, the remaining retractable components can still be used normally to maintain the pressure of the insulating liquid in the sealing unit. At the same time, the plurality of retractable components are sealed and connected in sequence, which can save the structure used to realize the sealed retractable components, simplify the overall structure of the pressure balancing mechanism, reduce the overall volume of the pressure balancing mechanism, and the plurality of retractable components are connected in sequence to realize linkage. When the retractable component with a pressure-bearing surface is deformed, the retractable component connected thereto will also move with it, which can facilitate the distribution of pressure to each retractable component.

[0007] In an optional embodiment, each telescopic component includes a bellows and a connector; the bellows and connectors of the multiple telescopic components are sealed and connected in sequence, and the bellows with an opening at the end is sealed and connected to the fixing member; the pressure-bearing surface is located on the side of the connector farthest from the fixing member away from the bellows. In this way, the bellows can be used to achieve telescopic expansion and contraction, and the connector can be used to achieve connection and sealing of the bellows.

[0008] In an optional embodiment, it also includes: a plurality of guide assemblies, which are arranged on the outer periphery of the bellows, and each guide assembly extends in a direction parallel to the axis of the bellows; one end of each guide assembly is connected to a fixing member, and a plurality of connectors can be slidably connected to each guide assembly to allow the bellows to expand and contract along the extension direction of the guide assembly. In this way, the guide assembly can be used to guide the axial compression and stretching directions of the bellows, so as to achieve uniform compression of the bellows by the insulating liquid, and prevent the bellows from being stuck during the expansion and contraction process. At the same time, the guide assembly can also support the bellows and the connectors to reduce the damage to the structure of the pressure balance mechanism caused by external vibrations during transportation, thereby extending the service life of the pressure balance mechanism.

[0009] In an optional embodiment, each guide assembly includes a guide shaft and a plurality of sleeves; one end of the guide shaft is fixedly connected to a fixing member; a plurality of sleeves are sequentially inserted into the guide shaft; and each connecting member is extended and retracted along the axial direction of the guide shaft through the sleeve. In this way, the guide shaft can slide closely against the sleeve to avoid displacement of the connecting member and the bellows. At the same time, if the friction on the inner wall of the sleeve is severe, the sleeve can be directly replaced, thereby facilitating the inspection and maintenance of the pressure balance mechanism.

[0010] In an optional embodiment, the connecting member and the guide shaft are made of metal, and the sleeve is made of non-metallic material. In this way, it is possible to avoid the generation of metal debris between the sleeve and the guide shaft to affect the properties of the insulating liquid, and to maintain the normal sliding of the sleeve relative to the guide shaft, so that the bellows can work normally.

[0011] In an optional embodiment, the sleeve includes a shoulder and a sleeve; the shoulder is connected to one end of the sleeve and is clamped to the connecting member, the sleeve is inserted into the first axial hole of the connecting member and is sleeved on the guide shaft; the sleeve is also provided with an annular groove, which is located on the side of the connecting member away from the shoulder; the pressure balancing mechanism also includes a retaining spring, which is clamped to the annular groove. In this way, when the sleeve of the first sleeve is inserted into the first axial hole, it can first be clamped to the connecting member using the shoulder, and then the retaining spring at the other end can be clamped to the other side of the connecting member, thereby facilitating the connection and fixation of the first sleeve to the first axial hole, and also facilitating the disassembly and replacement of the first sleeve.

[0012] In an optional embodiment, it also includes: a plurality of limit assemblies, which are arranged on the outer periphery of the bellows and are spaced apart from the guide assembly, and each limit assemblies extend in a direction parallel to the axis of the bellows; one end of each limit assemblies is connected to a fixing member, and the connecting member can move relative to the limit assemblies; the limit assemblies are used to limit the maximum compression and maximum stretching of each bellows. In this way, the phenomenon of over-compression or over-stretching of the bellows can be avoided, so as to reduce damage to the first bellows and the second bellows, thereby extending the service life of the first bellows and the second bellows.

[0013] In an optional embodiment, each limiting assembly includes a limiting shaft and at least one first limiting member; the limiting shaft includes a first shaft section and a second shaft section; one end of the first shaft section is connected to the fixing member, and the other end is connected to the second shaft section, and the shaft diameter of the first shaft section is greater than the shaft diameter of the second shaft section; the second shaft section is passed through the second shaft hole of each connecting member, and each connecting member can move relative to the second shaft section; the end of the first shaft section away from the fixing member is used to limit the maximum compression of the bellows connected to the fixing member; the first limiting member is located between two adjacent connecting members, connected to the connecting member of the two adjacent connecting members close to the fixing member, and sleeved on the second shaft section, and when each bellows is in a compressed state, the first limiting member is used to limit the maximum compression of the bellows between the two adjacent connecting members. In this way, it is easy to limit the maximum compression of the bellows.

[0014] In an optional embodiment, the first stopper is a stopper tube, and the inner diameter of the stopper tube is larger than the shaft diameter of the second shaft segment. In this way, when the connecting member moves relative to the stopper shaft, it can avoid contact with the second shaft segment, thereby preventing friction debris from being generated between the second shaft segment, the connecting member and the first stopper, which affects the insulation performance of the insulating liquid, and maintaining the normal sliding of the sleeve relative to the guide shaft, so that the bellows can work normally.

[0015] In an optional embodiment, the limiter assembly further includes a second limiter, which is located on the side of the pressure-bearing surface away from the bellows and connected to the guide assembly and the end of the limiter assembly away from the fixing member; the second limiter and the first limiter are used to limit the maximum stretching amount of the bellows when each bellows is in a stretched state. In this way, it is easy to limit the maximum stretching amount of the bellows.

[0016] In an optional embodiment, the second position-limiting member is a hollow annular structure in the middle. In this way, the hollow structure can be used to reduce the weight of the second position-limiting member, so as to reduce the overall weight of the pressure balancing mechanism. At the same time, when the fixing member is connected to the end cover of the sealing unit, the second position-limiting member is a structure away from the fixing member, which reduces the weight of the second position-limiting member and can also reduce the supporting load on the guide shaft and the fixing member, thereby improving the overall structural strength.

[0017] In an optional embodiment, the outer periphery of the annular structure of the second position limiter is provided with a plurality of cut corners symmetrical along the center of the second position limiter; the second position limiter is made of metal; the pressure balancing mechanism also includes: a plurality of support blocks made of non-metallic materials, the support blocks correspond to the cut corners one by one, and are connected to the cut corners; the side of the support block away from the cut corner is an arc surface, and the arc surfaces of the plurality of support blocks form a circular ring surface surrounding the second position limiter; each arc surface is used to contact the inner wall of the pressure-bearing cylinder. In this way, the support blocks made of non-metallic materials can protect the inner wall surface of the pressure-bearing cylinder while supporting the second position limiter.

[0018] In an optional embodiment, it further includes: an elastic buffer, which is sleeved on the guide component and / or the limit component and is located between the pressure-bearing surface and the second limit component; the elastic buffer is used to buffer the extrusion force between the pressure-bearing surface and the second limit component. In this way, when the connecting member with the pressure-bearing surface moves toward the second limit component, the pressure-bearing surface will first squeeze the elastic buffer, thereby preventing the connecting member from directly squeezing the second limit component, so as to avoid a large impact, vibration, etc. between the connecting member and the second limit component, thereby protecting the connecting member and the second limit component.

[0019] In an optional embodiment, the connecting member is provided with a weight-reducing structure, which is symmetrically arranged along the center of the connecting member. In this way, the weight of the connecting member itself can be reduced to reduce the supporting load of the guide shaft. At the same time, the weight-reducing structure symmetrically arranged along the center of the connecting member can also ensure the overall structural strength of the connecting member, so that the connecting member is evenly stressed.

[0020] In an optional embodiment, the weight-reducing structure includes a weight-reducing hole and a weight-reducing groove; the weight-reducing hole is located at the outer periphery of the bellows in the radial direction; the weight-reducing groove is located in the tube cavity of the bellows in the radial direction. In this way, the weight-reducing hole can be used to achieve weight reduction, and the flow of the insulating liquid outside the bellows can also be facilitated. The provision of the weight-reducing groove can achieve weight reduction while ensuring the sealing of the tube cavity of the bellows.

[0021] In an optional embodiment, there are two retractable components; the fixing member is provided with a first air hole, and the first air hole is used to pass gas when the bellows connected to the fixing member is tested for air tightness; the pressure balance mechanism also includes a first sealing member, and the first sealing member is sealed and connected to the first air hole when the air tightness test is completed; the connecting member with a pressure-bearing surface is provided with a second air hole, and the second air hole is used to pass gas when the bellows away from the fixing member is tested for air tightness; the pressure balance mechanism also includes a second sealing member, and the second sealing member is sealed and connected to the second air hole when the air tightness test is completed. In this way, it is easy to realize the air tightness test of the bellows.

[0022] In an optional embodiment, the edge of the fixing member is provided with a plurality of spaced notches, and the notches are used to provide channels for the flow of fluid, so as to facilitate the discharge of the liquid in the sealing unit.

[0023] In order to achieve the above-mentioned purpose, the second aspect of the present application also provides a sealing unit, comprising: a pressure-bearing cylinder, an end cover and a pressure balancing mechanism as described in the first aspect above; the pressure-bearing cylinder has a cylinder cavity opening toward one end along the axial direction, and the cylinder cavity is used to place electrical equipment and fill with insulating liquid; the end cover is connected to the side of the fixing member away from the bellows, and is sealed and connected to the opening of the cylinder cavity; the pressure balancing mechanism is located in the cylinder cavity, and the pressure balancing mechanism is used to balance the pressure of the insulating liquid in the cylinder cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0025] Figure 1 It is a three-dimensional structural schematic diagram of a viewing angle pressure balancing mechanism provided in an embodiment of the present application;

[0026] Figure 2 is a schematic diagram of a three-dimensional structure of another viewing angle pressure balancing mechanism provided in an embodiment of the present application;

[0027] Figure 3 The embodiment of the present application provides Figure 1 Schematic diagram of the cross-sectional structure cut along the AA direction;

[0028] Figure 4 is a schematic diagram of a three-dimensional structure of a partial structure of a second connecting member provided in an embodiment of the present application after being cut away;

[0029] Figure 5 is a schematic diagram of a three-dimensional structure of a partial structure of a first connecting member provided in an embodiment of the present application after being cut away;

[0030] Figure 6 is a schematic diagram of the three-dimensional structure of the first shaft sleeve provided in an embodiment of the present application;

[0031] Figure 7 The embodiment of the present application provides Figure 1 Schematic diagram of the cross-sectional structure cut along the BB direction;

[0032] Figure 8 is a structural schematic diagram of a second position-limiting member and a support block provided in an embodiment of the present application;

[0033] Fig. 9It is a schematic diagram of a three-dimensional structure of a partial structural decomposition of a sealing unit provided in an embodiment of the present application;

[0034] Fig.10 It is a schematic cross-sectional structural diagram of the sealing unit provided in this embodiment.

[0035] Graphic marking:

[0036] 100-pressure balancing mechanism; 1-fixing member; 11-notch; 12-first air hole; 2-retractable component; 20-pressure bearing surface; 21-bellows; 211-first bellows; 212-second bellows; 22-connecting member; 221-first connecting member; 222-second connecting member; 2221-second air hole; 2222-sink; 23-weight reduction structure; 231-weight reduction hole; 232-weight reduction groove; 3-first sealing member; 4-second sealing member; 5-guide assembly; 51-guide shaft; 52-first sleeve; 5 21-shoulder; 522-sleeve; 523-annular groove; 53-second sleeve; 6-circlip; 7-limiting assembly; 71-limiting shaft; 711-first shaft section; 712-second shaft section; 72-first limiting member; 73-second limiting member; 731-cut corner; 8-support block; 81-arc-shaped surface; 9-elastic buffer; a-first shaft hole; b-second shaft hole; 200-sealing unit; 201-pressure cylinder; 2011-opening; 2012-cylinder cavity; 202-end cover; 2021-drainage hole; 203-sealing plug. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be described clearly below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments of the present application, other embodiments obtained by ordinary technicians in this field without making creative work all belong to the protection scope of the present application.

[0038] In the following, the terms "first", "second", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0039] In addition, in the present application, directional terms such as "upper", "lower", "inner" and "outer" are defined relative to the orientation of the components schematically placed in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative description and clarification, and they can change accordingly according to the changes in the orientation of the components placed in the drawings.

[0040] In order to prevent the submarine equipment from being affected by seawater, the working components of the submarine equipment need to be isolated from the seawater. Therefore, when the submarine equipment is placed on the seabed, it will first be placed in the sealed cavity of the sealing unit to achieve isolation and protection of the submarine equipment.

[0041] However, since the submarine equipment is in a high-voltage and high-power working state for a long time, it will generate a lot of heat during the working process. The submarine equipment is in the sealed cavity of the sealing unit, and there is an air barrier between the submarine equipment and the outer wall of the sealing unit. At the same time, due to the large thermal resistance of the air, the heat generated by the high-power devices of the submarine equipment is difficult to effectively transfer to the seawater outside the sealing unit, so that the high-power devices cannot be cooled in time, affecting the working stability and service life of the submarine equipment.

[0042] In order to improve the heat dissipation effect of the submarine equipment in the sealed unit, the commonly used method is to fill the sealed cavity with insulating oil. The thermal resistance of insulating oil is smaller than that of air. In this way, the submarine equipment can use insulating oil as a heat transfer medium to transfer heat to the seawater outside the sealed unit. At the same time, the insulating oil also has an insulating effect, which can achieve insulation protection for the submarine equipment.

[0043] However, the sealing characteristics of the sealed cavity result in a certain volume inside the sealed cavity, and the amount of insulating oil that can be filled inside is also certain. When high-power devices generate high temperatures during operation, the insulating oil will expand and contract due to heat. In a sealed cavity with a certain volume, thermal expansion and contraction will cause the oil pressure of the insulating oil to change continuously. If the oil pressure of the insulating oil is too high, it will affect the structure and electrical connection of the submarine equipment in the sealed cavity, resulting in a decrease in the working stability of the submarine equipment.

[0044] In order to solve the above problems, the present application provides a pressure balancing mechanism and a sealing unit, which can balance the liquid pressure in the sealing chamber, have high reliability, and can improve the working stability of the subsea equipment.

[0045] like Figures 1 to 3 As shown, in the first aspect, this embodiment provides a pressure balancing mechanism 100, comprising a fixing member 1 and a plurality of retractable components 2. The fixing member 1 is used to be connected to a sealing unit.

[0046] Multiple retractable components 2 are arranged along the retractable direction (eg Figure 1 The plurality of retractable components 2 are sealed and connected in sequence along the direction of expansion and contraction (the direction in which the X-axis in the figure is located), and along the expansion and contraction direction, the retractable component 2 at one end of the plurality of retractable components 2 is sealed and connected to the fixing member 1, and the retractable component 2 at the other end has a pressure-bearing surface 20. The pressure-bearing surface 20 is used to withstand the pressure in the sealing unit, so that the pressure generated by thermal expansion and contraction in the sealing unit can drive the plurality of retractable components 2 to expand and contract, so as to change the volume inside the sealing unit and balance the pressure in the sealing unit.

[0047] It is worth noting that in the structural diagram of the pressure balancing mechanism 100 provided in this embodiment, the telescopic component 2 is in a state of not being telescoped. In other words, the pressure balancing mechanism 100 is in a state where the pressure-bearing surface 20 is not under pressure.

[0048] In this embodiment, a plurality of relatively independent retractable components 2 are arranged in a pressure balancing mechanism 100, and each retractable component 2 can form a pressure balancing unit to realize a redundant design of the pressure balancing unit. After one of the retractable components 2 is damaged, the remaining retractable components 2 can still be used normally to maintain the pressure of the insulating liquid in the sealing unit. At the same time, the plurality of retractable components 2 are sealed and connected in sequence, which can save the structure used to realize the sealed retractable components 2, simplify the overall structure of the pressure balancing mechanism 100, reduce the overall volume of the pressure balancing mechanism 100, and the plurality of retractable components 2 are connected in sequence to realize linkage. When the retractable component 2 with the pressure-bearing surface 20 is deformed, the retractable component 2 connected thereto will also move with it, which can facilitate the distribution of pressure to each retractable component 2.

[0049] Furthermore, each telescopic component 2 includes a bellows 21 and a connecting piece 22, and the bellows 21 and connecting pieces 22 of multiple telescopic components 2 are sealed and connected in sequence. The bellows 21 with an opening at the end is sealed and connected to the fixing piece 1, and the pressure-bearing surface 20 is located on the side of the connecting piece 22 that is farthest from the fixing piece 1 and is away from the bellows 21.

[0050] In this embodiment, the bellows 21 refers to a tubular elastic sensitive element formed by connecting a plurality of wave plates along the folding direction, which can absorb external pressure through its own deformation, thereby achieving pressure balance. The axial direction of the bellows 21 is the retractable direction of the bellows 21.

[0051] Exemplarily, the bellows 21 includes a plurality of stamped annular wave plates, and the plurality of annular wave plates can be welded by automatic high-precision argon arc welding equipment to form the bellows 21 .

[0052] Optionally, the thickness of the annular wave plate can be 0.1 mm to 0.25 mm, specifically 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, etc. The thinner the wave plate, the better the elasticity of the bellows 21, and the higher the sensitivity of deformation after being subjected to pressure. When the thickness of the wave plate is 0.1 mm, the elastic coefficient of the bellows 21 formed after welding can be lower than 3 N / mm, which is convenient for realizing high-precision pressure regulation.

[0053] In this embodiment, the fixing member 1 can achieve the sealing of the bellows 21 and can also facilitate the connection of the pressure balance mechanism 100 to the sealing unit. The connecting member 22 can not only achieve the sealing of the bellows 21, but also achieve the connection of two adjacent bellows 21. The fixing member 1 and the connecting member 22 can be flanges or cover plates, as long as they can achieve the sealing of the lumen of the bellows 21, which is not limited in this embodiment.

[0054] It is worth noting that the number of the retractable components 2 can be two, three, four or six, etc., and the specific number can be adjusted according to actual conditions.

[0055] In this embodiment, in order to facilitate the description of the structure of the pressure balancing mechanism 100 , two retractable components 2 are taken as an example for introduction.

[0056] When there are two retractable components 2, the pressure balancing mechanism 100 includes two bellows 21 and two connecting pieces 22. The bellows 21 connected to the fixing piece 1 is the first bellows 211, and the other bellows 21 is the second bellows 212. The connecting piece 22 sealedly connected to the first bellows 211 on the side away from the fixing piece 1 is the first connecting piece 221, and the other connecting piece 22 is the second connecting piece 222, and the side of the second connecting piece 222 away from the second bellows 212 is the pressure bearing surface 20. Along the axial direction of the first bellows 211 (such as Figure 1 In the direction of the X-axis in the figure, the fixing member 1, the first bellows 211, the first connecting member 221, the second bellows 212 and the second connecting member 222 are arranged in sequence.

[0057] The fixing member 1 is sealed and connected to one end of the first bellows 211, and the first connecting member 221 is sealed and connected to the end of the first bellows 211 away from the fixing member 1. In this way, the fixing member 1 and the first connecting member 221 can seal the lumen of the first bellows 211, so that the fixing member 1, the first bellows 211 and the first connecting member 221 form a pressure balancing unit, and the liquid pressure in the sealing unit is balanced through the stretching and compression of the first bellows 211.

[0058] Furthermore, the fixing member 1 and the first connecting member 221 can be connected to the first bellows 211 by sealing welding, so that the fixing member 1 and the first bellows 211, the first connecting member 221 and the first bellows 211 can have good sealing properties, thereby ensuring the connection strength.

[0059] At the same time, the second bellows 212 is coaxially arranged with the first bellows 211, one end of the second bellows 212 is sealed and connected to the side of the first connector 221 away from the first bellows 211, and the second connector 222 is sealed and connected to the end of the second bellows 212 away from the first connector 221. In this way, the first connector 221 and the second connector 222 can seal the lumen of the second bellows 212, so that the first connector 221, the second bellows 212 and the second connector 222 form another pressure balancing unit, and the pressure of the insulating liquid in the sealing unit is balanced through the stretching and compression of the second bellows 212.

[0060] Furthermore, the first connecting member 221 and the second connecting member 222 can be connected to the second bellows 212 by sealing welding, so that the first connecting member 221 and the second bellows 212, and the second connecting member 222 and the second bellows 212 can have good sealing properties to ensure connection strength.

[0061] In this embodiment, both sides of the first connector 221 are sealed and connected to the first bellows 211 and the second bellows 212, respectively, so that the first connector 221 is used to separate the tube cavities of the first bellows 211 and the second bellows 212. The first bellows 211 and the second bellows 212 can form two pressure balancing units, respectively, so that two groups of structures that can be used to balance the pressure of the insulating liquid can be formed in the sealing unit. In this way, two relatively independent pressure balancing units are arranged in one pressure balancing mechanism 100, so that the redundant design of the pressure balancing unit can be realized. After one of the bellows 21 is damaged, the other bellows 21 can still be used normally to maintain the pressure of the insulating liquid in the sealing unit. At the same time, the first connecting member 221 can realize the connection between the first bellows 211 and the second bellows 212 to simplify the overall structure of the pressure balancing mechanism 100 and reduce the overall volume of the pressure balancing mechanism 100, and the first bellows 211 and the second bellows 212 can be linked by the first connecting member 221. When the first bellows 211 is deformed, the second bellows 212 will also move accordingly, which can facilitate the distribution of pressure to the two bellows 21.

[0062] In addition, the tube cavity separation design of the first bellows 211 and the second bellows 212 divides the tube cavity of 2L into two independent tube cavities of L length, so that the tube cavity volume of each bellows 21 is half of the original. When one of the bellows 21 is damaged, the tube cavity of the bellows 21 will infiltrate the insulating liquid, but the tube cavity of the other bellows 21 will not infiltrate the insulating liquid. Compared with a bellows 21 of 2L length, two bellows 21 of L length can reduce the leakage of insulating liquid. In this way, if one of the bellows 21 is damaged, it can not only continue to maintain the pressure of the insulating liquid in the sealed unit, but also reduce the leakage of insulating liquid, and maintain the insulation and heat dissipation effect in the sealed unit.

[0063] In some embodiments, the fixing member 1 is also used to achieve connection with the end cover of the sealing unit, so as to fix the pressure balancing mechanism 100 inside the sealing unit. When the pressure balancing mechanism 100 is installed in the pressure-bearing cylinder of the sealing unit, a drainage hole is provided on the end cover to facilitate the injection of insulating liquid into the pressure-bearing cylinder and the discharge of insulating liquid. When the fixing member 1 is a flange, a plurality of spaced notches 11 can be provided on the edge of the fixing member 1, and the notches 11 can be used to provide a channel for the flow of insulating liquid, so that the insulating liquid in the pressure-bearing cylinder can flow to the drainage port of the end cover through the notches 11, so as to facilitate drainage and injection.

[0064] In some embodiments, the fixing member 1 is provided with a first air hole 12. After the fixing member 1, the first bellows 211 and the first connecting member 221 are connected, it is necessary to detect the air tightness of the lumen in the first bellows 211. When performing the air tightness test, the first air hole 12 can be used to pass a gas of a specified pressure into the lumen of the first bellows 211, so as to realize the air tightness test of the bellows 21 and the connection between the connecting member 22 and the bellows 21.

[0065] Furthermore, the pressure balancing mechanism 100 further includes a first sealing member 3. After the air tightness test of the first bellows 211 is completed, the first sealing member 3 is sealed and connected to the first air hole 12, thereby sealing the lumen of the first bellows 211.

[0066] Exemplarily, the first seal 3 may be a bolt, and the first seal 3 may be firstly connected to the first pore 12 by threads to reduce the axis offset between the first seal 3 and the first pore 12, thereby realizing the centering design of the first seal 3 and the first pore 12. After the first seal 3 is installed to the first pore 12, the connection gap between the first seal 3 and the first pore 12 is welded by welding technology to ensure the sealing effect.

[0067] Combination Figure 2 , Figure 3 and Figure 4As shown, in some embodiments, the second connector 222 is provided with a second air hole 2221. After the first connector 221, the second bellows 212 and the second connector 222 are connected, it is necessary to detect the air tightness of the lumen in the second bellows 212. During the air tightness detection, the second air hole 2221 can be used to pass a gas of a specified pressure into the lumen of the second bellows 212, so as to realize the air tightness detection of the bellows 21 and the connection between the connector 22 and the bellows 21.

[0068] Furthermore, the pressure balancing mechanism 100 further includes a second sealing member 4. After the air tightness test of the second bellows 212 is completed, the second sealing member 4 is sealed and connected to the second air hole 2221, thereby sealing the lumen of the second bellows 212.

[0069] Exemplarily, the second seal 4 may be a bolt, and the second seal 4 may be firstly connected to the second air hole 2221 by threads to reduce the axis offset between the second seal 4 and the second air hole 2221, thereby realizing the centering design of the second seal 4 and the second air hole 2221. After the second seal 4 is installed to the second air hole 2221, the connection gap between the second seal 4 and the second air hole 2221 is welded by welding technology to ensure the sealing effect.

[0070] Please refer again Figures 1 to 3 In some embodiments, the pressure balancing mechanism 100 further includes a plurality of guide assemblies 5. The plurality of guide assemblies 5 are disposed on the outer periphery of the first bellows 211 and the second bellows 212, and each guide assembly 5 extends in a direction parallel to the axis of the first bellows 211. One end of each guide assembly 5 is connected to the fixing member 1, and the first connecting member 221 and the second connecting member 222 are slidably connected to each guide assembly 5, so that the first bellows 211 and the second bellows 212 can be extended and retracted along the extension direction of the guide assembly 5.

[0071] When the pressure of the insulating liquid outside the first bellows 211 and the second bellows 212 changes, the first bellows 211 and the second bellows 212 will be stretched or compressed. The setting of the guide assembly 5 can make the first connecting member 221 move along the extension direction of the guide assembly 5 driven by the first bellows 211, and make the second connecting member 222 move along the extension direction of the guide assembly 5 driven by the second bellows 212, so as to limit the expansion and contraction of the first bellows 211 and the second bellows 212 along the axial direction, so as to achieve uniform compression of the first bellows 211 and the second bellows 212 by the insulating liquid, and also prevent the first bellows 211 and the second bellows 212 from being stuck during the expansion and contraction process.

[0072] In addition, when the pressure balancing mechanism 100 is installed on the sealing unit, the axis of the first bellows 211 may be parallel to the horizontal direction according to the placement direction of the sealing unit. The first bellows 211, the first connecting member 221, the second bellows 212 and the second connecting member 222 are cantilevered compared to the fixing member 1, and the setting of the guide assembly 5 can also support the first bellows 211, the first connecting member 221, the second bellows 212 and the second connecting member 222. In this way, the bending of the first bellows 211 and the second bellows 212 can be avoided, which affects the elastic sensitivity and structural strength of the first bellows 211 and the second bellows 212. At the same time, the support of the guide assembly 5 can also reduce the damage to the structure of the pressure balancing mechanism 100 caused by external vibration during transportation, thereby extending the service life of the pressure balancing mechanism 100.

[0073] Optionally, the number of guide assemblies 5 may be four, and the four guide assemblies 5 are evenly distributed on the outer circumference of the bellows 21. In this way, the guide assembly 5 can guide and support the first bellows 211 and the second bellows 212 in four directions: up, down, left, and right, so as to improve the force balance of the guide assembly 5 during the guiding and supporting process, so as to improve the structural stability of the first bellows 211 and the second bellows 212. It is understandable that the number of guide assemblies 5 can also be six, eight, etc., which is not limited in this embodiment.

[0074] Please combine Figures 3 to 6 Specifically, the guide assembly 5 includes a guide shaft 51, one end of which is fixedly connected to the fixing member 1, and the first connecting member 221 and the second connecting member 222 are respectively provided with first axial holes a corresponding to each guide shaft 51, and the guide shaft 51 is sequentially penetrated through the first axial hole a of the first connecting member 221 and the first axial hole a of the second connecting member 222, so that the first connecting member 221 and the second connecting member 222 can slide relative to the guide shaft 51.

[0075] In an example, when the first connecting member 221 and the second connecting member 222 are flanges, the first shaft hole a for passing the guide shaft 51 can be set at the edge of the flange.

[0076] In another example, when the first connecting member 221 and the second connecting member 222 are cover structures, lugs can be provided at corresponding positions of the cover structures to facilitate providing the first shaft hole a on the lugs. It can be understood that the specific arrangement of the first shaft hole a is not limited in this embodiment.

[0077] It is worth noting that the number of the first axial holes a on the first connecting member 221 and the second connecting member 222 corresponds to the number of the guide shafts 51 , and in this embodiment, the number of the first axial holes a is not limited.

[0078] Further, the guide assembly 5 further includes a first sleeve 52 and a second sleeve 53. The first sleeve 52 is connected to the first shaft hole a of the first connecting member 221 and is sleeved on the guide shaft 51. The second sleeve 53 is connected to the first shaft hole a of the second connecting member 222 and is sleeved on the guide shaft 51. In this way, the first connecting member 221 can slide along the guide shaft 51 through the first sleeve 52, and the second connecting member 222 can slide along the guide shaft 51 through the second sleeve 53.

[0079] When the first connecting member 221 moves along the guide shaft 51, if there is a large gap between the first axial hole a of the first connecting member 221 and the guide shaft 51, the moving track of the first connecting member 221 may deviate, resulting in uneven force on the first bellows 211 or the second bellows 212. By setting the first sleeve 52 between the first axial hole a of the first connecting member 221 and the guide shaft 51, the first connecting member 221 can be closely fitted with the guide shaft 51, preventing the first bellows 211 or the second bellows 212 from deflecting during the telescopic process. At the same time, when the first connecting member 221 moves relative to the guide shaft 51, if the first axial hole a is directly fitted with the guide shaft 51, the first axial hole a will be continuously worn, which may easily cause the first axial hole a to deform. By setting the first sleeve 52, the first axial hole a can be prevented from being deformed by friction. If the friction of the inner wall of the sleeve is serious, the sleeve can be directly replaced, thereby facilitating the inspection and maintenance of the pressure balancing mechanism 100.

[0080] It is worth noting that the function of the second sleeve 53 is the same as that of the first sleeve 52, which will not be described again here.

[0081] When the first sleeve 52 and the second sleeve 53 move along the guide shaft 51, friction will be generated with the guide shaft 51. In order to ensure the overall structural strength of the pressure balancing mechanism 100, the first connecting member 221, the second connecting member 222 and the guide shaft 51 are usually made of metal. If the first sleeve 52 and the second sleeve 53 are also made of metal, metal debris will be generated between the sleeve and the guide shaft 51 during the friction process. After the metal debris is mixed with the insulating liquid, it may adhere to the seabed equipment inside the sealing unit with the flow of the insulating liquid, affecting the electrical connection stability of the seabed equipment. At the same time, the metal debris may also block the relative sliding between the sleeve and the guide shaft 51, affecting the normal operation of the bellows 21.

[0082] Based on the above reasons, in order to avoid the generation of metal debris during the friction process and affect the insulation performance of the insulating liquid, the first sleeve 52 and the second sleeve 53 can be made of non-metallic materials, such as PE, PVC, etc. In this way, it is possible to avoid the generation of metal debris between the guide shaft 51 and the sleeve, which affects the properties of the insulating liquid, and maintain the normal sliding of the sleeve relative to the guide shaft 51, so that the bellows 21 can work normally.

[0083] Exemplarily, the pressure balancing mechanism 100 further includes a retaining spring 6 , and the first sleeve 52 is fixed to the first connecting member 221 via the retaining spring 6 .

[0084] Specifically, the first sleeve 52 includes a shoulder 521 and a sleeve 522. The shoulder 521 is connected to one end of the sleeve 522 and is clamped to one side of the first connecting member 221. The sleeve 522 is inserted into the first axial hole a of the first connecting member 221 and sleeved on the guide shaft 51. The sleeve 522 is also provided with an annular groove 523, which is located on the side of the first connecting member 221 away from the shoulder 521, and the retaining ring 6 is clamped to the annular groove 523. In this way, when the sleeve 522 of the first sleeve 52 is inserted into the first axial hole a, the shoulder 521 can be firstly clamped to the first connecting member 221, and then the retaining ring 6 at the other end can be clamped to the other side of the first connecting member 221, so as to facilitate the connection and fixation of the first sleeve 52 and the first axial hole a, and also facilitate the disassembly and replacement of the first sleeve 52.

[0085] Optionally, when the first sleeve 52 and the first connecting member 221 are made of different materials, the first sleeve 52 and the first connecting member 221 may also be connected by gluing. In this embodiment, the specific connection between the first sleeve 52 and the first connecting member 221 is not limited.

[0086] It is worth noting that the connection method between the second sleeve 53 and the second connecting member 222 and the structure of the second sleeve 53 can refer to the description of the first sleeve 52, which will not be repeated here.

[0087] When the guide shaft 51 supports the first bellows 211, the first connector 221, the second bellows 212 and the second connector 222, the weight of each structure will affect the support load of the guide shaft 51. Therefore, a weight reduction structure 23 can be provided on the first connector 221 and the second connector 222. The weight reduction structure 23 on the first connector 221 is symmetrically arranged along the center of the first connector 221, and the weight reduction structure 23 on the second connector 222 is symmetrically arranged along the center of the second connector 222. In this way, the weight of the first connector 221 and the second connector 222 can be reduced to reduce the support load of the guide shaft 51. At the same time, the weight reduction structure 23 symmetrically arranged along the center of the first connector 221 and the second connector 222 can also ensure the overall structural strength of the first connector 221 and the second connector 222, so that the first connector 221 and the second connector 222 are evenly stressed.

[0088] Specifically, the weight-reducing structure 23 includes a weight-reducing hole 231 and a weight-reducing groove 232 .

[0089] The weight-reducing holes 231 are located at the outer periphery of the second bellows 212 in the radial direction. In this way, the weight-reducing holes 231 can be used to reduce weight and facilitate the flow of insulating liquid outside the bellows 21 .

[0090] The weight-reducing groove 232 is located in the second bellows 212 along the radial direction, so that the sealing performance of the lumen of the bellows 21 can be ensured while achieving weight reduction.

[0091] Optionally, the weight-reducing grooves 232 may be radially arranged with the center of the first connecting member 221 or the second connecting member 222 as the center, so as to achieve uniform distribution of the weight-reducing grooves 232 .

[0092] Furthermore, the two sides of the first connecting member 221 are respectively connected to the second bellows 212 and the first bellows 211 , and the weight reduction grooves 232 can be respectively arranged on the two sides of the first connecting member 221 , thereby achieving bidirectional weight reduction of the first connecting member 221 .

[0093] In some embodiments, along the axial direction, the thickness of the fixing member 1 is greater than the thickness of the second connecting member 222, so that the structural strength of the fixing member 1 is greater than that of the second connecting member 222, so that after the fixing member 1 is connected to the sealing unit, it can bear the structural loads of the first bellows 211, the first connecting member 221, the second bellows 212, the second connecting member 222 and the guide shaft 51. The second connecting member 222 is arranged away from the fixing member 1, and by making the thickness of the second connecting member 222 less than the thickness of the fixing member 1, the weight of the second connecting member 222 can be reduced, so as to further reduce the overall weight of the pressure balancing mechanism 100, thereby reducing the supporting load on the guide shaft 51 and the fixing member 1.

[0094] Meanwhile, the thickness of the first connecting member 221 is greater than that of the second connecting member 222. Thus, it is convenient to weld the first bellows 211 and the second bellows 212 on both sides of the first connecting member 221 to ensure the welding strength of the first connecting member 221 and the first bellows 211 and the second bellows 212.

[0095] Please combine Figure 1 , Figure 4 , Figure 5 and Figure 7 In some embodiments, the pressure balancing mechanism 100 further includes a plurality of limiter assemblies 7. The plurality of limiter assemblies 7 are disposed on the outer periphery of the first bellows 211 and the second bellows 212 and are spaced apart from the guide assembly 5. Each limiter assemblies 7 extends in a direction parallel to the axis of the first bellows 211.

[0096] One end of each limiting assembly 7 is connected to the fixing member 1, and the first connecting member 221 and the second connecting member 222 can move relative to the limiting assembly 7 to drive the first bellows 211 and the second bellows 212 to move relative to the limiting assembly 7. The limiting assembly 7 can limit the maximum compression and maximum extension of the first bellows 211 and the second bellows 212. In this way, the first bellows 211 and the second bellows 212 can be prevented from being over-compressed or over-stretched, the damage to the first bellows 211 and the second bellows 212 can be reduced, and the service life of the first bellows 211 and the second bellows 212 can be extended.

[0097] Optionally, there may be four limiting components 7, and at the same time, the four limiting components 7 are arranged at equal intervals, so that the first connecting member 221 and the second connecting member 222 can be uniformly limited in the four directions of upper, lower, left and right.

[0098] Specifically, the limiting assembly 7 includes a limiting shaft 71. The first connecting member 221 and the second connecting member 222 are provided with a second shaft hole b corresponding to the limiting shaft 71, and the limiting shaft 71 is passed through the second shaft hole b, so that the limiting shaft 71 can be used to limit the minimum distance between the first connecting member 221 and the fixing member 1, and limit the minimum distance between the second connecting member 222 and the fixing member 1. Through the limiting effect of the limiting shaft 71, the maximum compression amount of the first bellows 211 and the second bellows 212 can be limited.

[0099] Specifically, when the first connecting member 221 moves toward the fixing member 1, the first bellows 211 is in a compressed state, and the state in which the first connecting member 221 and the fixing member 1 are at the minimum distance corresponds to the state in which the first bellows 211 is at the maximum compression. When the second connecting member 222 moves toward the fixing member 1, the second bellows 212 is in a compressed state, and the state in which the second connecting member 222 and the fixing member 1 are at the minimum distance corresponds to the state in which the second bellows 212 is at the maximum compression. In this way, the limiting shaft 71 can be used to prevent the first bellows 211 and the second bellows 212 from being over-compressed, so as to reduce damage to the first bellows 211 and the second bellows 212, thereby extending the service life of the first bellows 211 and the second bellows 212.

[0100] In some embodiments, the limiting shaft 71 includes a first shaft segment 711 and a second shaft segment 712 .

[0101] One end of the first shaft section 711 is connected to the fixing member 1, and the other end is connected to the second shaft section 712. The shaft diameter of the first shaft section 711 is larger than the shaft diameter of the second shaft section 712. The second shaft section 712 is provided in the second shaft hole b of the first connecting member 221 and the second connecting member 222. At the same time, the hole diameter of the second shaft hole b is also larger than the shaft diameter of the second shaft section 712 and smaller than the shaft diameter of the first shaft section 711. The first connecting member 221 and the second connecting member 222 can move relative to the second shaft section 712. In this way, when the first connecting member 221 moves toward the fixing member 1, the end of the first shaft section 711 away from the fixing member 1 can abut against the first connecting member 221 to limit the minimum distance between the first connecting member 221 and the fixing member 1. In other words, when the first bellows 211 is compressed, the first shaft section 711 can limit the maximum compression amount of the first bellows 211, thereby preventing the first bellows 211 from being over-compressed.

[0102] The limiting assembly 7 further includes a first limiting member 72. The first limiting member 72 is connected to a side of the first connecting member 221 facing the second connecting member 222, and is sleeved on the second shaft section 712. Thus, when the second connecting member 222 moves toward the fixing member 1, the end of the second limiting member 73 away from the first connecting member 221 can abut against the second connecting member 222 to limit the minimum distance between the second connecting member 222 and the fixing member 1. In other words, when the second bellows 212 is compressed, the first limiting member 72 can limit the maximum compression amount of the second bellows 212, thereby preventing the second bellows 212 from being over-compressed.

[0103] Exemplarily, the first stopper 72 may be a stopper tube, the inner diameter of which is larger than the shaft diameter of the second shaft segment 712, and the aperture of the second shaft hole b is larger than the shaft diameter of the second shaft segment 712. In this way, when the first connecting member 221 and the second connecting member 222 move relative to the stopper shaft 71, they can avoid contact with the second shaft segment 712, thereby preventing friction debris from being generated between the second shaft segment 712, the first connecting member 221 and the first stopper 72 to affect the insulation performance of the insulating liquid, and maintaining the normal sliding of the sleeve relative to the guide shaft 51, so that the bellows 21 can work normally.

[0104] It is worth noting that the number of the second axial holes b on the first connecting member 221 and the second connecting member 222 corresponds to the number of the limiting shafts 71 , and in this embodiment, the number of the second axial holes b is not limited.

[0105] Exemplarily, when there are four first axial holes a and four second axial holes b, the first axial holes a and the second axial holes b can be arranged at the edges of the first connecting member 221 and the second connecting member 222, and the first axial holes a and the second axial holes b are arranged in sequence at intervals. At this time, the weight-reducing hole 231 can be arranged between the first axial hole a and the second axial hole b.

[0106] Please combine Figure 2 , Figure 7 and Figure 8 Furthermore, the limiting component 7 also includes a second limiting member 73.

[0107] The second stopper 73 is located at a side of the second connecting member 222 away from the first connecting member 221, and is connected to the end of the guide shaft 51 and the stopper shaft 71 away from the fixing member 1. When the first connecting member 221 and the second connecting member 222 move away from the fixing member 1, the first bellows 211 and the second bellows 212 are in a stretched state. When the second connecting member 222 abuts against the second stopper 73, the second connecting member 222 and the fixing member 1 are in a maximum distance state, and at the same time, the end of the first stopper 72 away from the first connecting member 221 can also abut against the second connecting member 222 to limit the maximum distance between the first connecting member 221 and the fixing member 1.

[0108] Specifically, the state where the second connecting member 222 is at the maximum distance from the fixing member 1 corresponds to the state of the maximum stretching amount of the second bellows 212, and the state where the first connecting member 221 is at the maximum distance from the fixing member 1 corresponds to the state of the maximum stretching amount of the first bellows 211. In this way, the first limiter 72 and the second limiter 73 can be used to limit the maximum stretching amount of the first bellows 211 and the second bellows 212, so as to avoid the phenomenon of over-stretching of the first bellows 211 and the second bellows 212, reduce damage to the first bellows 211 and the second bellows 212, and thus extend the service life of the first bellows 211 and the second bellows 212.

[0109] Exemplarily, the second stopper 73 is a hollow annular structure in the middle. In this way, the hollow structure can be used to reduce the weight of the second stopper 73, so as to reduce the overall weight of the pressure balancing mechanism 100. At the same time, when the fixing member 1 is connected to the end cover of the sealing unit, the second stopper 73 is a structure away from the fixing member 1, which reduces the weight of the second stopper 73 and can also reduce the support load on the guide shaft 51 and the fixing member 1, thereby improving the overall structural strength. In addition, the second stopper 73 is an annular structure, which can also facilitate the flow of the insulating liquid, so that the pressure of the insulating liquid directly acts on the pressure-bearing surface 20, so that the telescopic component 2 can adjust the pressure in time.

[0110] It is worth noting that in other examples, the second limit member 73 can also be a plurality of independent limit blocks, limit plates and other structures connected to the guide shaft 51 and the end of the limit shaft 71 away from the fixed member 1. In this embodiment, the specific structure of the second limit member is not limited.

[0111] Furthermore, in order to further reduce the weight of the second stopper 73, the second stopper 73 can be made of aluminum alloy while ensuring the structural strength of the second stopper 73. It is understandable that in other embodiments, the second stopper 73 can also be made of other lightweight materials such as plastic, which is not limited in this embodiment.

[0112] In one example, when the second stopper 73 is made of metal, a plurality of cut corners 731 are provided on the outer periphery of the annular structure of the second stopper 73, which are symmetrical along the center of the second stopper 73. The pressure balancing mechanism 100 further includes a plurality of support blocks 8 made of non-metallic materials, the number of support blocks 8 corresponds to the number of cut corners 731, and the support blocks 8 are connected to the cut corners 731 accordingly. The side of the support block 8 facing away from the cut corners 731 is an arcuate surface 81, and the arcuate surfaces 81 of the plurality of support blocks 8 can form a circular surface (such as Figure 8 (as shown by the dotted lines in the figure), so as to utilize each arc surface 81 to contact the inner wall of the pressure-bearing cylinder. When the pressure balancing mechanism 100 is installed in the pressure-bearing cylinder, the support block 8 can contact the inner wall of the pressure-bearing cylinder, thereby supporting the second position-limiting member 73 to avoid the second position-limiting member 73 from being suspended. At the same time, when the second position-limiting member 73 is made of metal, the support block 8 made of non-metallic material is used to support the second position-limiting member 73, which can avoid the metal structure from contacting the inner wall surface of the pressure-bearing cylinder, thereby avoiding scratching the inner wall surface of the pressure-bearing cylinder and affecting the air tightness of the inner wall surface of the pressure-bearing cylinder. In this way, the support block 8 made of non-metallic material can protect the inner wall surface of the pressure-bearing cylinder while supporting the second position-limiting member 73.

[0113] Optionally, there may be eight cut corners 731 and eight support blocks 8 , and the eight cut corners 731 are evenly distributed on the edge of the second limiting member 73 , so that the second limiting member 73 is evenly stressed.

[0114] In another example, when the material of the second limiting member 73 is a non-metallic material, the outer diameter of the annular structure of the second limiting member 73 can be equal to the inner diameter of the pressure cylinder, so that the second limiting member 73 can directly abut against the inner wall of the pressure cylinder to support the second limiting member 73 by utilizing the inner wall of the pressure cylinder.

[0115] In some embodiments, the pressure balancing mechanism 100 further includes a plurality of elastic buffer members 9 .

[0116] In one example, each elastic buffer member 9 is sleeved on the guide shaft 51 and is located between the second connecting member 222 and the second stopper 73. In another example, each elastic buffer member 9 is sleeved on the stopper shaft 71 and is located between the second connecting member 222 and the second stopper 73. In another example, each elastic buffer member 9 is sleeved on the guide shaft 51 and the stopper shaft 71 and is located between the second connecting member 222 and the second stopper 73.

[0117] In this way, when the second connecting member 222 moves toward the second limiting member 73, the second connecting member 222 will first squeeze the elastic buffer member 9, thereby preventing the second connecting member 222 from directly squeezing the second limiting member 73, so as to avoid large impacts, vibrations, etc. between the second connecting member 222 and the second limiting member 73, thereby protecting the second connecting member 222 and the second limiting member 73.

[0118] Exemplarily, the elastic buffer member 9 may be an elastic rubber ring, an elastic silicone gasket, etc., which is not limited in the present embodiment.

[0119] Please combine Figure 3 and Figure 4 Furthermore, since the second connecting member 222 is provided with a second sleeve 53 sleeved on the guide shaft 51, a recessed groove 2222 can be provided on the side of the second connecting member 222 facing the second stopper 73, and the recessed groove 2222 is provided corresponding to the second sleeve 53. In this way, the second sleeve 53 can be located in the recessed groove 2222, thereby avoiding the presence of a protrusion of the second sleeve 53 on the surface of the second connecting member 222, so that the second connecting member 222 can contact each elastic buffer member 9 at the same time, avoiding the problem of uneven force.

[0120] Please combine Fig. 9 and Fig.10 In a second aspect, this embodiment further provides a sealing unit 200, comprising a pressure-bearing cylinder 201, an end cover 202, and the pressure balancing mechanism 100 as described in the first aspect above.

[0121] The pressure cylinder 201 has a cylinder cavity 2012 with an opening 2011 at one end along the axial direction, and the cylinder cavity 2012 is used to place submarine equipment and fill with insulating liquid. The submarine equipment may be electronic equipment, electronic devices, and circuit structures that need to be isolated from seawater. It is understandable that when the sealing unit 200 is applied to other scenarios, other electrical equipment that needs to be sealed may also be prevented from entering the cylinder cavity 2012, such as motors, electronic controllers, power distribution equipment, cables, switches, sockets, sensors, and circuit boards, which are not limited in this embodiment.

[0122] It is understandable that the pressure-bearing cylinder 201 may be formed by a tubular structure and a cover plate sealed at one end of the tubular structure, or the pressure-bearing cylinder 201 may be formed in one piece. In this embodiment, the specific structure of the pressure-bearing cylinder 201 is not limited.

[0123] The insulating liquid can be a natural insulating oil, such as vegetable oil, mineral oil, etc. The insulating liquid can also be a synthetic insulating oil, such as silicone oil, ester insulating oil, ether insulating oil, etc. Filling the cylinder with insulating liquid can not only achieve insulation protection for the submarine equipment, but also improve the thermal conductivity and heat dissipation effect of the submarine equipment.

[0124] The end cap 202 is connected to the side of the fixing member 1 away from the first bellows 211. The fixing member 1 and the end cap 202 can be connected by a sealing bolt, which is convenient for disassembly and installation and can also achieve sealing. The end cap 202 is also connected to the pressure-bearing cylinder 201 to seal the opening 2011 of the cylinder cavity 2012 to achieve sealing of the cylinder cavity 2012.

[0125] When the end cover 202 is connected to the pressure-bearing cylinder 201, the pressure balancing mechanism 100 is located in the cylinder cavity 2012 to balance the pressure of the insulating liquid in the cylinder cavity 2012, so as to maintain the pressure balance in the cylinder cavity 2012 and protect the equipment in the cylinder cavity 2012 when the insulating liquid expands or contracts due to heat.

[0126] When the pressure balancing mechanism 100 is located in the barrel cavity 2012 and the end cover 202 is sealed and connected to the opening 2011, the bellows 21 of the pressure balancing mechanism 100 will occupy a part of the volume in the barrel cavity 2012. At this time, the volume of the barrel cavity 2012 is equal to the sum of the volume of the pressure balancing mechanism 100 in the non-deformed state and the volume of the insulating liquid.

[0127] If the insulating liquid in the cylinder cavity 2012 of the pressure cylinder 201 expands due to heat, the expansion force of the insulating liquid can squeeze the pressure-bearing surface 20 of the pressure balancing mechanism 100, so that the first bellows 211 and the second bellows 212 are compressed, thereby reducing the volume occupied by the pressure balancing mechanism 100 in the cylinder cavity 2012, so as to provide more volume for the insulating liquid, thereby preventing the pressure in the cylinder cavity 2012 from increasing after the insulating liquid expands due to heat.

[0128] If the insulating liquid in the cylinder cavity 2012 of the pressure cylinder 201 cools down and shrinks, the shrinkage force of the insulating liquid and the pressure difference in the bellows can cause the first bellows 211 and the second bellows 212 to stretch, thereby increasing the volume occupied by the pressure balancing mechanism 100 in the cylinder cavity 2012, so as to provide less volume for the insulating liquid, thereby preventing the pressure in the cylinder cavity 2012 from decreasing after the insulating liquid shrinks due to cold.

[0129] Furthermore, a drain hole 2021 is provided on the end cap 202, and the drain hole 2021 is connected to the barrel cavity 2012. When the insulating liquid in the barrel cavity 2012 needs to be discharged, the drain hole 2021 can be used for discharge. Alternatively, when the insulating liquid needs to be injected into the barrel cavity 2012, it can also be injected through the drain hole 2021.

[0130] The sealing unit 200 further includes a sealing plug 203 . When liquid discharge or liquid injection is not required, the sealing plug 203 is sealingly connected to the liquid discharge hole 2021 to seal the cylinder cavity 2012 of the pressure-bearing cylinder 201 .

[0131] It should be noted that those skilled in the art will easily think of other embodiments of the present application after considering the specification and practicing the application disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary technical means in the art that are not disclosed in the present application. The specification and examples are only regarded as exemplary, and the true scope of the present application is indicated by the claims.

[0132] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A pressure balancing mechanism, characterized in that: include: A fixing member, used for fixedly connecting to the sealing unit; A plurality of retractable components, wherein the plurality of retractable components are sealed and connected in sequence along a retracting direction; Along the telescopic direction, the telescopic components located at one end of the plurality of telescopic components are sealed and connected to the fixing member, and the telescopic components located at the other end have a pressure-bearing surface; The pressure-bearing surface is used to bear the pressure in the sealing unit, and the plurality of retractable components are used to retract and contract under the action of the pressure to balance the pressure.

2. The pressure balancing mechanism according to claim 1, characterized in that: Each of the telescopic components includes a bellows and a connecting piece; The bellows and the connecting piece of the plurality of telescopic components are sealed and connected in sequence, and the bellows with an opening at the end is sealed and connected to the fixing piece; The pressure-bearing surface is located on a side of the connecting member that is farthest from the fixing member and faces away from the corrugated tube.

3. The pressure balancing mechanism according to claim 2, characterized in that: Also includes: A plurality of guide assemblies are arranged on the outer periphery of the corrugated pipe, and each of the guide assemblies extends in a direction parallel to the axis of the corrugated pipe; One end of each guide component is connected to the fixing member, and a plurality of connecting members can be slidably connected to each guide component so that the bellows can be extended and retracted along the extension direction of the guide component.

4. The pressure balancing mechanism according to claim 3, characterized in that: Each of the guide assemblies comprises a guide shaft and a plurality of bushings; One end of the guide shaft is fixedly connected to the fixing member; A plurality of the shaft sleeves are sequentially inserted into the guide shaft; Each of the connecting members is extended and retracted along the axial direction of the guide shaft through the shaft sleeve.

5. The pressure balancing mechanism according to claim 4, characterized in that: The connecting piece and the guide shaft are made of metal; The material of the shaft sleeve is non-metallic material.

6. The pressure balancing mechanism according to claim 5, characterized in that: The shaft sleeve comprises a shaft shoulder and a sleeve; The shoulder is connected to one end of the sleeve and clamped to the connecting piece. The sleeve is inserted into the first axial hole of the connecting member and sleeved on the guide shaft; The sleeve is also provided with an annular groove, and the annular groove is located on a side of the connecting member away from the shaft shoulder; The pressure balancing mechanism further comprises a clamping spring, and the clamping spring is clamped in the annular groove.

7. The pressure balancing mechanism according to claim 3, characterized in that: Also includes: A plurality of limit assemblies are arranged on the outer periphery of the bellows and are spaced apart from the guide assembly, and each of the limit assemblies extends in a direction parallel to the axis of the bellows; One end of each of the limiting components is connected to the fixing member, and the connecting member can move relative to the limiting component; The limiting assembly is used to limit the maximum compression and maximum stretching of each of the bellows.

8. The pressure balancing mechanism according to claim 7, characterized in that: Each of the limiting components includes a limiting shaft and at least one first limiting member; The limiting shaft includes a first shaft section and a second shaft section; One end of the first shaft segment is connected to the fixing member, and the other end is connected to the second shaft segment, and the shaft diameter of the first shaft segment is larger than the shaft diameter of the second shaft segment; The second shaft section is passed through the second shaft hole of each of the connecting members, and each of the connecting members can move relative to the second shaft section; An end of the first shaft section away from the fixing member is used to limit the maximum compression amount of the bellows connected to the fixing member; The first limiting member is located between two adjacent connecting members, connected to the connecting member close to the fixing member among the two adjacent connecting members, and sleeved on the second shaft segment; When each of the bellows is in a compressed state, the first limiting member is used to limit the maximum compression amount of the bellows between two adjacent connecting members.

9. The pressure balancing mechanism according to claim 8, characterized in that: The first limiting member is a limiting tube, and the inner diameter of the limiting tube is larger than the shaft diameter of the second shaft segment.

10. The pressure balancing mechanism according to claim 8, characterized in that: The limiting assembly further includes a second limiting member, which is located on a side of the pressure-bearing surface away from the bellows and is connected to the guide assembly and an end of the limiting assembly away from the fixing member; The second limiting member and the first limiting member are used to limit the maximum stretching amount of the bellows when each of the bellows is in a stretched state.

11. The pressure balancing mechanism according to claim 10, characterized in that: The second limiting member is a ring-shaped structure with a hollow middle portion.

12. The pressure balancing mechanism according to claim 11, characterized in that: The outer periphery of the annular structure of the second position-limiting member is provided with a plurality of cut corners symmetrical along the center of the second position-limiting member; The second limiting member is made of metal; The pressure balancing mechanism further includes: a plurality of support blocks made of non-metallic material, the support blocks corresponding to the cut corners one by one and connected to the cut corners; The side of the support block facing away from the cut corner is an arc-shaped surface, and the arc-shaped surfaces of the plurality of support blocks form an annular surface surrounding the second position-limiting member; Each of the arc-shaped surfaces is used to contact the inner wall of the pressure-bearing cylinder.

13. The pressure balancing mechanism according to claim 10, characterized in that: Also includes: An elastic buffer, sleeved on the guide assembly and / or the limit assembly, and located between the pressure-bearing surface and the second limit member; The elastic buffer is used to buffer the extrusion force between the pressure-bearing surface and the second limiting member.

14. The pressure balancing mechanism according to any one of claims 2 to 13, characterized in that: The connecting member is provided with a weight-reducing structure, and the weight-reducing structure is symmetrically arranged along the center of the connecting member.

15. The pressure balancing mechanism according to claim 14, characterized in that: The weight-reducing structure includes a weight-reducing hole and a weight-reducing groove; The weight-reducing holes are located at the outer periphery of the bellows in the radial direction; The weight-reducing groove is located in the tube cavity of the corrugated tube along the radial direction.

16. The pressure balancing mechanism according to any one of claims 2 to 13, characterized in that: There are two retractable components; The fixing member is provided with a first air hole, and the first air hole is used to pass gas when the air tightness test is performed on the bellows connected to the fixing member; The pressure balancing mechanism further comprises a first sealing member, which is sealed and connected to the first air hole when the air tightness test is completed; The connecting member having the pressure-bearing surface is provided with a second air hole, and the second air hole is used to pass gas when the air tightness test of the bellows away from the fixing member is performed; The pressure balancing mechanism further comprises a second sealing member, which is sealed and connected to the second air hole when the air tightness test is completed.

17. The pressure balancing mechanism according to any one of claims 1 to 13, characterized in that: The edge of the fixing member is provided with a plurality of spaced notches, and the notches are used to provide channels for fluid flow.

18. A sealing unit, characterized in that: include: A pressure-bearing cylinder, an end cover, and a pressure balancing mechanism as described in any one of claims 1 to 17; The pressure-bearing cylinder has a cylinder cavity opened toward one end along the axial direction, and the cylinder cavity is used to place electrical equipment and be filled with insulating liquid; The end cover is connected to the side of the fixing member facing away from the bellows and is sealed to the opening of the cylinder cavity; The pressure balancing mechanism is located in the barrel cavity, and is used to balance the pressure of the insulating liquid in the barrel cavity.

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