Direct current bushing with efficient heat dissipation and multiple sealing functions

Abstract

The invention relates to a direct current bushing with efficient heat dissipation and multiple sealing functions, which comprises a core body, the upper part of the core body is arranged in an insulating jacket, and a current-carrying tube is arranged in the core body; the upper end of the insulating jacket is provided with a head conductive column, the lower end of the core is provided with a tail conductive column, the upper end of the current-carrying tube extends out of the core and then is connected with the head conductive column, and the lower end of the current-carrying tube is connected with the tail conductive column. A head sealing assembly is arranged at the upper end of the current-carrying pipe, a liquid medium is arranged in the head sealing assembly, the head sealing assembly comprises a sealing main plate, an oil injection hole for injecting the liquid medium is formed in the sealing main plate, an oil injection plug is arranged in the oil injection hole, and an oil injection sealing cover is arranged on the upper side of the oil injection hole; and a sealing isolation plate for isolating the liquid medium from the tail conductive column is arranged in the lower part of the current-carrying tube. According to the invention, efficient heat dissipation is realized by using the liquid medium in the current-carrying pipe, so that the temperature rise of the sleeve can be effectively controlled, and meanwhile, the sealing reliability between the sleeve and the converter transformer can be improved while the sealing of the liquid medium is ensured by using a multi-sealing structure.

Description

Technical Field

[0001] This invention relates to the field of DC power transmission technology, specifically a DC bushing with efficient heat dissipation and multiple sealing functions. Background Technology

[0002] Ultra-high voltage direct current (UHVDC) transmission technology has been widely used due to its unique advantages in long-distance, large-capacity power transmission. The DC bushing is a key component of the converter transformer. One side needs to be installed on the outdoor converter transformer, leading the transformer winding's output terminals out of the tank. The other side needs to penetrate the wall and extend into the valve hall to form an electrical connection with the converter valve. The reliability of the DC bushing directly determines the safety and stability of the entire UHVDC transmission system.

[0003] Unlike alternating current (AC), direct current (DC) is uniformly distributed across the entire conductor cross-section and is a stable value. Its heating power is continuous and uninterrupted, causing heat to accumulate in the DC bushing conductor, eventually reaching thermal equilibrium at a higher temperature. This localized temperature increase further increases the conductivity loss of the insulation material at that point, generating even more heat and further raising the temperature. Additionally, the converter valve generates a large amount of harmonic current during operation. These high-frequency currents experience additional losses due to the skin effect, significantly increasing the total heat generation. Excessive temperature caused by these factors can lead to localized overheating and insulation failure in the DC bushing conductor, and may even cause thermal breakdown, resulting in more serious bushing failures and potentially damaging the entire converter transformer.

[0004] In addition, the DC bushing is installed on the converter transformer. The inside of the transformer is filled with insulating oil, whose main functions are insulation and cooling. The seal between the bushing and the transformer is used to ensure the absolute isolation between the insulating oil inside the converter transformer and the external environment. If the seal is not tight and oil leakage occurs, the oil and other flammable materials that leak out may encounter high temperature or electric arc, which may cause the transformer tank to burst, fire, etc., thereby endangering the valve hall and the electrical equipment inside the valve hall. This will not only cause equipment damage, but also have a huge impact on the stability of the power grid and the reliability of power supply. Summary of the Invention

[0005] The purpose of this invention is to provide a DC bushing with efficient heat dissipation and multiple sealing functions. It utilizes the liquid medium inside the current-carrying tube to achieve efficient heat dissipation, thereby effectively controlling the temperature rise of the bushing. The multiple sealing structure not only ensures the sealing of the liquid medium, but also improves the sealing reliability between the bushing and the converter transformer.

[0006] The objective of this invention is achieved through the following technical solution: A DC bushing with efficient heat dissipation and multiple sealing functions includes a core, the upper part of which is disposed within an insulating outer sleeve, and a current-carrying tube disposed inside the core. A head conductive post is provided at the upper end of the insulating outer sleeve, and a tail conductive post is provided at the lower end of the core. The upper end of the current-carrying tube extends out of the core and connects to the head conductive post, while the lower end of the current-carrying tube connects to the tail conductive post. A head sealing assembly is provided at the upper end of the current-carrying tube, and a liquid medium is disposed inside. The head sealing assembly includes a sealing main board, and the sealing main board has an oil injection hole for injecting the liquid medium. An oil injection plug is disposed inside the oil injection hole, and an oil injection cap is disposed on its upper side. A sealing isolation plate is provided in the lower part of the current-carrying tube to separate the liquid medium from the tail conductive post.

[0007] An oil filling seal is provided between the oil filling plug and the sealing main board, and a sealing cap seal is provided between the oil filling cap and the sealing main board; a sealing cap assembly is provided on the upper side of the sealing main board, and the sealing cap assembly includes a first sealing cap plate and a second sealing cap plate, wherein the first sealing cap plate is located on the upper side of the sealing main board, and a main board upper seal is provided between the lower side of the first sealing cap plate and the sealing main board, a first cap plate seal is provided between the outer side of the first sealing cap plate and the inner wall of the upper end of the flow carrier tube, a first inner hole is provided in the middle of the first sealing cap plate, and the oil filling cap is located in the first inner hole; a second sealing cap plate is located on the upper side of the first sealing cap plate, and a second cap plate seal is provided between the second sealing cap plate, the first sealing cap plate, and the inner wall of the upper end of the flow carrier tube, and a second inner hole is provided in the middle of the second sealing cap plate, exposing the oil filling cap.

[0008] The upper inner wall of the current-carrying tube is provided with a support stop, and the lower end of the sealing main board is supported by the support stop. The upper outer side of the sealing main board is provided with a clamping nut that is threadedly connected to the inner wall of the current-carrying tube. The upper outer side of the second inner hole is provided with a stop plane, and a cover plate fixing element is provided on the stop plane. The sealing main board, the first sealing cover plate, and the second sealing cover plate are fixedly connected by the cover plate fixing element.

[0009] The lower end of the conductive post at the head is provided with a connecting cavity, and the upper end of the current-carrying tube is inserted into the connecting cavity. The outer wall of the upper end of the current-carrying tube and the cavity wall of the connecting cavity are provided with a conductive contact finger and a sealing support. In addition, a gap is left between the upper end of the current-carrying tube and the bottom of the connecting cavity.

[0010] The core includes a core insulating sleeve and a positioning tube disposed inside the core insulating sleeve, with the current-carrying tube disposed in the positioning tube; the tail conductive post includes a tail post, with the upper end of the tail post inserted into the lower end of the current-carrying tube, and a tail conductive contact and a tail first sealing element provided between the tail post and the current-carrying tube, with a sealing positioning seat provided at the lower end of the tail post, and the lower end of the core disposed on the sealing positioning seat.

[0011] The lower end of the tail column is provided with a nested part, and the lower end of the nested part is provided with a tail flange. The sealing positioning seat is provided with a positioning inner hole, and the lower end of the positioning inner hole is provided with a positioning groove. The nested part is inserted into the positioning inner hole, and a second tail seal is provided between the outer surface of the nested part and the hole wall of the positioning inner hole. The tail flange is fitted into the positioning groove, and a third tail seal is provided between the tail flange and the bottom of the positioning groove.

[0012] The sealing positioning seat includes an upper positioning protrusion and a lower positioning support platform, wherein the positioning protrusion is threaded into the positioning tube, and the lower end of the positioning tube and the lower end of the core insulating sleeve are both located on the positioning support platform; the tail flange is fixedly connected to the sealing positioning seat through a core connecting element.

[0013] A tail support ring is provided between the lower end of the current-carrying tube and the lower end of the positioning tube, and a tail fixing ring is provided on the lower side of the tail support ring. The tail fixing ring is fixed to the lower end of the current-carrying tube by a tail fastening element, and a gap is left between the tail fixing ring and the sealing positioning seat.

[0014] A positioning support ring is provided between the current-carrying tube and the positioning tube; the current-carrying tube includes multiple hollow tubes, and adjacent hollow tubes are connected by a built-in connecting sleeve; a guide cone is provided at the upper end of the tail conductive post.

[0015] An installation flange is fixedly provided on the outer side of the core, and a through-wall flange is provided on the upper side of the installation flange. The upper side of the through-wall flange is fixedly connected to the lower end of the insulating jacket. A metal cover plate is provided on the upper end of the insulating jacket, and the head conductive post is fixedly connected to the metal cover plate. An umbrella skirt is provided on the outer side of the insulating jacket.

[0016] The advantages and positive effects of this invention are as follows: 1. The present invention provides a liquid medium inside the current-carrying tube to achieve rapid temperature convection, thereby achieving efficient heat dissipation. This ensures the temperature balance of the bushing and avoids thermal breakdown of the insulation. At the same time, the head sealing component at the upper end of the current-carrying tube does not affect the injection of the liquid medium and can ensure the effective sealing of the liquid medium inside the current-carrying tube.

[0017] 2. This invention utilizes the oil injection plug in the head sealing assembly to inject liquid medium into the flow-carrying tube, while simultaneously sealing the oil injection plug with an oil injection cap. Furthermore, both the first and second sealing caps have inner holes in their middle sections that expose the oil injection caps, thus not affecting the liquid medium injection operation. Additionally, this invention ensures a seal around the oil injection hole through the oil injection seal between the oil injection plug and the main sealing plate, and the cap seal between the oil injection cap and the main sealing plate. The main sealing plate seal between the main sealing plate and the first sealing cap, the first cap seal outside the first sealing cap, and the second cap seal outside the second sealing cap ensure a seal around the outer edge of the main sealing plate, thereby ensuring effective sealing of the liquid medium inside the flow-carrying tube.

[0018] 3. This invention improves the sealing reliability between the bushing and the converter transformer by utilizing multiple seals. Specifically, the invention uses the aforementioned head sealing assembly and sealing support to ensure the sealing performance of the upper end of the bushing, while the tail conductive post and sealing positioning seat work together to ensure the sealing performance of the lower end of the bushing. A second tail seal is provided between the outer surface of the nested part of the tail conductive post and the positioning inner hole of the sealing positioning seat, and a third tail seal is provided between the tail flange of the tail conductive post and the positioning groove of the sealing positioning seat. In addition, a first tail seal is provided between the tail column of the tail conductive post and the current-carrying tube, and the positioning protrusion of the sealing positioning seat is threadedly connected to the positioning pipe of the core. Through the above structural design, this invention can ensure the sealing of the lower end of the bushing.

[0019] 4. This invention utilizes the cooperation between a sealing positioning seat and a tail conductive post to ensure reliable positioning between the tail conductive post and the core. The nested part of the tail conductive post is inserted into the positioning inner hole of the sealing positioning seat, while the positioning protrusion of the sealing positioning seat is inserted into the positioning tube of the core. At the same time, the lower end of the positioning tube of the core and the lower end of the core insulating sleeve are both located on the positioning support platform outside the sealing positioning seat. This achieves both auxiliary positioning of the tail conductive post and the core, and isolation between the tail conductive post and the core.

[0020] 5. The present invention utilizes the cooperation between the sealing positioning seat and the tail conductive post to ensure a reliable connection between the tail conductive post and the core. The positioning protrusion of the sealing positioning seat is threadedly connected to the positioning pipe of the core, and the lower end of the core is limited and fixed by the positioning support platform on the outside of the sealing positioning seat. The tail flange at the lower end of the tail conductive post is fixed to the sealing positioning seat by the core connecting element (such as screw).

[0021] 6. This invention utilizes the sealing support and the connecting cavity on the lower side of the head conductive post to limit the position of the upper end of the current-carrying tube, thereby effectively controlling the uneven contact between the current-carrying tube and the head conductive finger caused by the deflection deformation of the current-carrying tube under long-term tilt. This improves the reliability of the electrical connection between the current-carrying tube and the head conductive finger. At the same time, the tail conductive finger on the tail conductive post adopts an annular current-carrying finger with greater elastic deformation, which has better tolerance.

[0022] 7. In this invention, there is a gap between the upper end of the current-carrying tube and the connecting cavity of the head conductive post, and at the same time, there is also a sufficient gap between the lower end of the current-carrying tube and the sealing positioning seat at the lower end of the tail conductive post. In this way, the present invention can allow the current-carrying tube to undergo a certain amount of deformation due to thermal expansion and contraction, without affecting the normal operation of the sleeve.

[0023] 8. The present invention provides a tail support ring between the lower end of the current-carrying tube and the positioning tube to ensure support. The tail fixing ring on the lower side of the tail support ring is fixed to the lower end of the current-carrying tube through a tail fastening element. At the same time, there is a sufficient distance between the tail fixing ring and the sealing positioning seat to allow for the deformation of the current-carrying tube due to thermal expansion and contraction.

[0024] 9. The current-carrying tube of the present invention includes multiple hollow tubes, and adjacent hollow tubes are connected by built-in connecting sleeves. This facilitates flexible adjustment of the current-carrying tube length according to actual needs during production. At the same time, the present invention utilizes positioning support rings that are equally spaced between the current-carrying tube and the positioning tube to ensure that the two are coaxial. This can further avoid the situation where the current-carrying tube and the conductive contacts at both ends cannot make uniform contact. In addition, the positioning support ring is thick in the middle and thin at both ends, which can make the current-carrying tube more smoothly inserted into the inner cavity of the positioning tube. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of the present invention. Figure 2 for Figure 1 Schematic diagram of the structure of the medium current-carrying tube. Figure 3 for Figure 2 A schematic diagram of the structure of the conductive pillar in the middle head. Figure 4 for Figure 1 A schematic diagram of the conductive pillar in the middle and tail section.

[0026] Among them, 1 is a metal cover plate, 2 is an insulating jacket, 201 is an upper flange, 202 is a lower flange, 3 is a through-wall flange, 4 is a mounting flange; 5 is a core, 501 is a positioning tube, 502 is a core insulating sleeve; 6 is a current-carrying tube, 601 is a positioning support ring, 602 is a tail support ring, 603 is a tail fixing ring, 604 is a tail fastening element, 605 is a connecting sleeve, 606 is a liquid medium, and 607 is a sealing isolation plate; 7 is the head conductive post, 701 is the head fixing element, 702 is the head conductive contact finger, 703 is the sealing support, 704 is the head column, 7041 is the head cavity, and 705 is the connecting cavity; 8 is the tail conductive post, 801 is the guide cone, 802 is the tail conductive contact finger, 803 is the tail first seal, 804 is the tail second seal, 805 is the tail third seal, 806 is the tail column, and 8061 is... The tail cavity includes: 8062 (nested part), 8063 (tail flange), 807 (core connecting element), and 808 (conical connecting element); 9 is the head sealing assembly, 901 is the sealing main plate, 9011 is the oil injection hole, 9012 is the support stop, 902 is the clamping nut, 903 is the oil injection plug, 904 is the oil injection cap, 9041 is the cap cavity, 9042 is the cap fixing element, and 905 is the first sealing cover plate. 1 is the first inner hole, 906 is the second sealing cover plate, 9061 is the second inner hole, 9062 is the cover plate fixing element, 907 is the oil injection seal, 908 is the sealing cover seal, 909 is the main plate seal, 910 is the first cover plate seal, 911 is the second cover plate seal, 10 is the sealing positioning seat, 1001 is the positioning support platform, 1002 is the positioning inner hole, 1003 is the positioning groove, and 1004 is the positioning protrusion. Detailed Implementation

[0027] The invention will now be described in further detail with reference to the accompanying drawings.

[0028] like Figures 1-4 As shown, the present invention includes a core 5, the upper part of which is disposed within an insulating jacket 2, and a current-carrying tube 6 is disposed inside it; a head conductive post 7 is provided at the upper end of the insulating jacket 2, and a tail conductive post 8 is provided at the lower end of the core 5; the upper end of the current-carrying tube 6 extends out of the core 5 and is connected to the head conductive post 7, and the lower end of the current-carrying tube 6 is connected to the tail conductive post 8; as shown Figures 2-3 As shown, the upper end of the current-carrying tube 6 is provided with a head sealing assembly 9, and the inside of the current-carrying tube 6 is provided with a liquid medium 606. During operation, the liquid medium 606 serves as a heat transfer medium, enabling rapid temperature convection within the current-carrying tube 6, thereby ensuring temperature balance and preventing insulation thermal breakdown. In this embodiment, the liquid medium 606 can be a suitable organic material with good thermal conductivity, as needed.

[0029] like Figure 3As shown, in this embodiment, the upper inner wall of the flow-carrying tube 6 is provided with a support stop 9012, the head sealing assembly 9 includes a sealing main plate 901, and the lower end of the sealing main plate 901 is supported by the support stop 9012. The upper outer side of the sealing main plate 901 is provided with a clamping nut 902 that is threadedly connected to the inner wall of the flow-carrying tube 6. The sealing main plate 901 is provided with an oil injection hole 9011 for injecting liquid medium 606. The oil injection hole 9011 is provided with an oil injection plug 903 inside and an oil injection cap 904 on the upper side. The upper side of the sealing main plate 901 is provided with a sealing cap assembly. An oil injection sealing element 907 is provided between the oil injection plug 903 and the sealing main plate 901, and a sealing cap sealing element 908 is provided between the oil injection cap 904 and the sealing main plate 901.

[0030] like Figure 3 As shown, in this embodiment, the upper end of the oil injection hole 9011 is provided with an installation groove, and the oil injection plug 903 is provided in the installation groove. An oil injection sealing element 907 is provided between the oil injection plug 903 and the bottom of the installation groove.

[0031] like Figure 3 As shown, in this embodiment, the oil filling cap 904 has a cap cavity 9041 inside and a cap flange on the lower outer side. The oil filling plug 903 is located on the lower side of the cap cavity 9041. The cap flange is fixed to the sealing main plate 901 by a cap fixing element 9042 (such as a screw), and a cap sealing element 908 is provided between the cap flange and the sealing main plate 901. After the oil filling cap 904 is disassembled, the oil filling hole 9011 is exposed for injecting liquid medium 606.

[0032] like Figure 3 As shown, in this embodiment, the sealing cover assembly includes a first sealing cover plate 905 and a second sealing cover plate 906. The first sealing cover plate 905 is disposed on the upper side of the sealing main plate 901, and a main plate sealing element 909 is provided between the lower side of the first sealing cover plate 905 and the sealing main plate 901. A first cover plate sealing element 910 is provided between the outer side of the first sealing cover plate 905 and the inner wall of the upper end of the current-carrying tube 6. A first inner hole 9051 is provided in the middle of the first sealing cover plate 905, and an oil filling seal 904 is disposed in the first inner hole 9051.

[0033] like Figure 3As shown, in this embodiment, the second sealing cover plate 906 is disposed on the upper side of the first sealing cover plate 905, and a second cover plate sealing element 911 is provided between the second sealing cover plate 906, the first sealing cover plate 905, and the inner wall of the upper end of the flow-carrying pipe 6; the second sealing cover plate 906 has a second inner hole 9061 in the middle for exposing the oil filling cover 904, and a stop plane is provided on the outer side of the upper end of the second inner hole 9061, and a cover plate fixing element 9062 (such as a bolt) is provided on the stop plane. The sealing main plate 901, the first sealing cover plate 905, and the second sealing cover plate 906 are fixedly connected by the cover plate fixing element 9062.

[0034] In this embodiment, the oil injection seal 907, the cap seal 908, the main board seal 909, the first cover plate seal 910, and the second cover plate seal 911 can all be equipped with suitable sealing elements, such as sealing rings, as needed. The oil injection seal 907 and the cap seal 908 mainly ensure the sealing around the oil injection hole 9011, while the main board seal 909, the first cover plate seal 910, and the second cover plate seal 911 mainly ensure the sealing of the outer edge of the main board 901. Thus, while meeting the requirements for injecting the liquid medium 606 into the flow carrier tube 6, the liquid medium 606 can also be effectively sealed in the flow carrier tube 6.

[0035] like Figures 2-3 As shown, in this embodiment, the lower end of the head conductive post 7 is provided with a connecting cavity 705, and the upper end of the current-carrying tube 6 is inserted into the connecting cavity 705. A head conductive contact 702 and a sealing support 703 are provided between the outer wall of the upper end of the current-carrying tube 6 and the cavity wall of the connecting cavity 705. The head conductive contact 702 is used to realize the electrical connection between the current-carrying tube 6 and the head conductive post 7. The sealing support 703 and the connecting cavity 705 cooperate to limit the position of the upper end of the current-carrying tube 6, thereby effectively controlling the uneven contact between the current-carrying tube 6 and the head conductive contact 702 caused by deflection deformation under long-term tilting, thus improving the reliability of the electrical connection between the current-carrying tube 6 and the head conductive contact 702. A gap is left between the upper end of the current-carrying tube 6 and the bottom of the connecting cavity 705, which allows for the deformation of the current-carrying tube 6 due to thermal expansion and contraction. In this embodiment, the sealing support 703 is made of polytetrafluoroethylene (PTFE).

[0036] like Figures 1-3 As shown in this embodiment, the upper end of the insulating jacket 2 is provided with a metal cover plate 1, and the head conductive post 7 includes an upper head post body 704 and a lower connecting part. The head post body 704 is provided with a head cavity 7041, the connecting part is provided with a connecting cavity 705, and the lower end of the connecting part is provided with a head connecting flange. The head connecting flange is fixed to the metal cover plate 1 by a head fixing element 701 (such as a bolt).

[0037] like Figures 1-2 As shown, in this embodiment, the core 5 includes a core insulating sleeve 502 and a positioning tube 501 disposed inside the core insulating sleeve 502. A current-carrying tube 6 is disposed within the positioning tube 501, and a positioning support ring 601 is provided between the current-carrying tube 6 and the positioning tube 501. In this embodiment, the positioning support ring 601 is arranged at equal intervals along the length of the current-carrying tube 6 and has a shape that is thicker in the middle and thinner at both ends, so that the current-carrying tube 6 can be inserted more smoothly into the inner cavity of the positioning tube 501, while keeping the current-carrying tube 6 and the positioning tube 501 coaxial. Furthermore, in this embodiment, the positioning support ring 601 is made of polytetrafluoroethylene (PTFE) material with good insulation properties, and the core insulating sleeve 502 is made of an epoxy resin impregnated paper mixture.

[0038] like Figure 2 As shown, in this embodiment, the current-carrying tube 6 includes multiple hollow tubes, and adjacent hollow tubes are connected by built-in connecting sleeves 605. In this embodiment, the connecting sleeve 605 has threads on its outer side to connect with the hollow tubes, and the joints of adjacent hollow tubes are fixed and sealed by welding. The inner sides of both ends of the connecting sleeve 605 are rounded.

[0039] like Figures 1-2 and Figure 4 As shown, in this embodiment, the tail conductive post 8 includes a tail post body 806 with an internal tail cavity 8061, and the upper end of the tail post body 806 is inserted into the lower end of the current-carrying tube 6. A tail conductive contact 802 and a tail first sealing member 803 are provided between the tail post body 806 and the current-carrying tube 6. The tail conductive contact 802 is used to realize electrical connection. A sealing positioning seat 10 is provided at the lower end of the tail post body 806, and the lower end of the core 5 is disposed on the sealing positioning seat 10.

[0040] like Figure 4 As shown, in this embodiment, a tail support ring 602 is provided between the lower end of the current-carrying tube 6 and the positioning tube 501, and a tail fixing ring 603 is provided on the lower side of the tail support ring 602. The tail fixing ring 603 is fixed to the lower end of the current-carrying tube 6 by a tail fastening element 604 (such as a screw). The tail support ring 602 is used to support the lower end of the current-carrying tube 6 and the positioning tube 501, while the tail fixing ring 603 and the sealing positioning seat 10 are left with sufficient distance to allow for the deformation of the current-carrying tube 6 due to thermal expansion and contraction.

[0041] like Figure 4As shown, in this embodiment, the lower end of the tail column 806 is provided with a nesting part 8062, and the lower end of the nesting part 8062 is provided with a tail flange 8063. The sealing positioning seat 10 is provided with a positioning inner hole 1002, and the lower end of the positioning inner hole 1002 is provided with a positioning groove 1003. The nesting part 8062 is inserted into the positioning inner hole 1002, and a tail second sealing member 804 is provided between the outer surface of the nesting part 8062 and the hole wall of the positioning inner hole 1002. The tail flange 8063 is fitted into the positioning groove 1003, and a tail third sealing member 805 is provided between the tail flange 8063 and the bottom of the positioning groove 1003.

[0042] In this embodiment, the tail first seal 803, tail second seal 804, and tail third seal 805 can be made of suitable sealing elements, such as sealing rings, as needed. The above-mentioned seals, together with the sealing positioning seat 10, can ensure the sealing of the lower end of the current-carrying tube 6 and the core 5, that is, ensure the reliable sealing of the lower end of the sleeve of the present invention.

[0043] like Figure 4 As shown, in this embodiment, the tail flange 8063 is fixedly connected to the sealing positioning seat 10 by a core connecting element 807 (such as a screw).

[0044] like Figure 4 As shown, in this embodiment, the sealing positioning seat 10 includes an upper positioning protrusion 1004 and a lower positioning support platform 1001, wherein the positioning protrusion 1004 is threaded into the positioning tube 501, and the lower end of the positioning tube 501 and the lower end of the core insulating sleeve 502 are both provided on the positioning support platform 1001.

[0045] like Figure 2 As shown, in this embodiment, a sealing isolation plate 607 is provided inside the lower part of the current-carrying tube 6 to separate the liquid medium 606 and the tail conductive column 8. Additionally, as shown... Figure 2 and Figure 4 As shown, the upper end of the tail conductive post 8 is provided with a guide cone 801 to facilitate insertion into the current-carrying tube 6. In this embodiment, the guide cone 801 is fixedly connected to the upper end of the tail post 806 by a cone connecting element 808 (such as a screw).

[0046] like Figure 1 As shown, in this embodiment, a mounting flange 4 is fixedly provided on the outer side of the core 5, and a through-wall flange 3 is provided on the upper side of the mounting flange 4. The upper side of the through-wall flange 3 is fixedly connected to the lower end of the insulating jacket 2.

[0047] like Figure 1As shown in this embodiment, the insulating jacket 2 has an upper flange 201 at the upper end and a lower flange 202 at the lower end. The upper flange 201 is fixedly connected to the metal cover plate 1, and the lower flange 202 is fixedly connected to the through-wall flange 3. The insulating jacket 2 has a skirt on its outer side.

[0048] The working principle of this invention is as follows: This invention firstly incorporates a liquid medium 606 inside the current-carrying tube 6 to rapidly achieve temperature convection within the tube, thereby realizing efficient heat dissipation. This ensures temperature balance in the bushing and prevents thermal breakdown of the insulation. Simultaneously, the head sealing assembly 9 at the upper end of the current-carrying tube 6 neither interferes with the injection of the liquid medium 606 nor hinders the effective sealing of the liquid medium 606 inside the tube. For example... Figure 3 As shown, in the head sealing assembly 9 inside the upper end of the flow carrier tube 6, the oil filling seal 907 between the oil filling plug 903 and the sealing main board 901, and the cover seal 908 between the oil filling cap 904 and the sealing main board 901 can ensure the sealing around the oil filling hole 9011. The main board seal 909 between the sealing main board 901 and the first sealing cover 905, the first cover seal 910 outside the first sealing cover 905, and the second cover seal 911 outside the second sealing cover 906 can ensure the sealing of the outer edge of the sealing main board 901.

[0049] Secondly, in addition to utilizing the head sealing assembly 9 and the sealing support 703 between the inner wall of the connecting cavity 705 on the lower side of the head conductive post 7 and the outer wall of the upper end of the current-carrying tube 6 to ensure the sealing performance of the upper end of the sleeve, the present invention also... Figures 1-2 and Figure 4 As shown, the lower end of the tail conductive post 8 of the present invention is provided with a sealing positioning seat 10, and a second tail sealing element 804 is provided between the outer surface of the nested part 8062 of the tail conductive post 8 and the positioning inner hole 1002 of the sealing positioning seat 10. A third tail sealing element 805 is provided between the tail flange 8063 of the tail conductive post 8 and the positioning groove 1003 of the sealing positioning seat 10. In addition, a first tail sealing element 803 is provided between the tail post 806 of the tail conductive post 8 and the current carrying tube 6, and the positioning protrusion 1004 of the sealing positioning seat 10 is threadedly connected to the positioning tube 501 of the core 5. The present invention can ensure the sealing performance of the lower end of the sleeve through the above structural combination, and the sealing positioning seat 10 can also ensure reliable positioning and reliable connection between the tail conductive post 8 and the core 5.

[0050] Again Figure 3 and Figure 4As shown, the present invention achieves electrical connection through the head conductive contact 702 between the head conductive post 7 and the upper end of the current-carrying tube 6, and the tail conductive contact 802 between the tail conductive post 8 and the lower end of the current-carrying tube 6. The sealing support 703 cooperates with the connecting cavity 705 on the lower side of the head conductive post 7 to limit the position of the upper end of the current-carrying tube 6, thereby effectively controlling the uneven contact between the current-carrying tube 6 and the head conductive contact 702 caused by the deflection deformation of the current-carrying tube 6 under long-term tilt. This improves the reliability of the electrical connection between the current-carrying tube 6 and the head conductive contact 702. The tail conductive contact 802 on the tail conductive post 8 adopts an annular current-carrying contact with greater elastic deformation, which has better tolerance. In addition, the present invention uses the positioning support ring 601 with equal spacing between the current-carrying tube 6 and the positioning tube 501 to ensure that the two are coaxial, which can further avoid the situation where the current-carrying tube 6 and the conductive contacts at both ends cannot make uniform contact.

[0051] Finally, as Figure 3 and Figure 4 As shown, this invention takes into account that the current-carrying tube 6 will deform due to thermal expansion and contraction. Therefore, a gap is left between the upper end of the current-carrying tube 6 and the connecting cavity 705 of the head conductive post 7, and a sufficient gap is also left between the lower end of the current-carrying tube 6 and the sealing positioning seat 10. In this way, while ensuring the sealing of the liquid medium 606 inside the current-carrying tube 6 and the electrical connection between both ends of the current-carrying tube 6 and the corresponding conductive posts, this invention can also allow the current-carrying tube 6 to undergo a certain amount of deformation due to thermal expansion and contraction, without affecting the normal operation of the sleeve. For example... Figure 4 As shown, the present invention provides a tail support ring 602 separately between the lower end of the current-carrying tube 6 and the positioning tube 501, and the tail fixing ring 603 on the lower side of the tail support ring 602 is fixedly connected to the lower end of the current-carrying tube 6 through the tail fastening element 604. There is a sufficient distance between the tail fixing ring 603 and the sealing positioning seat 10 to allow the deformation of the current-carrying tube 6 due to thermal expansion and contraction.

Claims

1. A DC bushing with efficient heat dissipation and multiple sealing functions, characterized in that: The device includes a core (5), with the upper part of the core (5) housed within an insulating jacket (2). A current-carrying tube (6) is located inside the core (5). A head conductive post (7) is located at the upper end of the insulating jacket (2), and a tail conductive post (8) is located at the lower end of the core (5). The upper end of the current-carrying tube (6) extends out of the core (5) and connects to the head conductive post (7), while the lower end of the current-carrying tube (6) connects to the tail conductive post (8). A head sealing assembly (9) is located at the upper end of the current-carrying tube (6). The head sealing assembly (9) includes a sealing main board (901) and an oil injection hole (9011) for injecting the liquid medium (606) is provided on the sealing main board (9011). The oil injection hole (9011) is provided with an oil injection plug (903) inside and an oil injection cap (904) on the upper side. The lower part of the flow-carrying tube (6) is provided with a sealing isolation plate (607) that separates the liquid medium (606) and the tail conductive column (8).

2. The DC bushing with high-efficiency heat dissipation and multiple sealing functions according to claim 1, characterized in that: An oil filling seal (907) is provided between the oil filling plug (903) and the sealing main board (901), and a sealing cap seal (908) is provided between the oil filling cap (904) and the sealing main board (901); a sealing cap assembly is provided on the upper side of the sealing main board (901), and the sealing cap assembly includes a first sealing cap plate (905) and a second sealing cap plate (906), wherein the first sealing cap plate (905) is located on the upper side of the sealing main board (901), and a main board upper seal (909) is provided between the lower side of the first sealing cap plate (905) and the sealing main board (901), and the first sealing cap plate (905)... A first cover plate seal (910) is provided between the outer side of the flow carrier tube (6) and the inner wall of the upper end. A first inner hole (9051) is provided in the middle of the first sealing cover plate (905), and an oil filling cap (904) is provided in the first inner hole (9051). A second sealing cover plate (906) is provided on the upper side of the first sealing cover plate (905), and a second cover plate seal (911) is provided between the second sealing cover plate (906), the first sealing cover plate (905), and the inner wall of the upper end of the flow carrier tube (6). A second inner hole (9061) is provided in the middle of the second sealing cover plate (906) to expose the oil filling cap (904).

3. The DC bushing with high-efficiency heat dissipation and multiple sealing functions according to claim 2, characterized in that: The upper inner wall of the current-carrying tube (6) is provided with a support stop (9012), and the lower end of the sealing main plate (901) is supported by the support stop (9012). The upper outer side of the sealing main plate (901) is provided with a clamping nut (902) which is threadedly connected to the inner wall of the current-carrying tube (6). The upper outer side of the second inner hole (9061) is provided with a stop plane, and a cover plate fixing element (9062) is provided on the stop plane. The sealing main plate (901), the first sealing cover plate (905), and the second sealing cover plate (906) are fixedly connected by the cover plate fixing element (9062).

4. The DC bushing with high-efficiency heat dissipation and multiple sealing functions according to claim 1, characterized in that: The lower end of the head conductive post (7) is provided with a connecting cavity (705), and the upper end of the current-carrying tube (6) is inserted into the connecting cavity (705). The upper outer wall of the current-carrying tube (6) and the cavity wall of the connecting cavity (705) are provided with a head conductive contact (702) and a sealing support (703). In addition, there is a gap between the upper end of the current-carrying tube (6) and the bottom of the connecting cavity (705).

5. The DC bushing with high-efficiency heat dissipation and multiple sealing functions according to claim 1, characterized in that: The core (5) includes a core insulating sleeve (502) and a positioning tube (501) disposed inside the core insulating sleeve (502). The current-carrying tube (6) is disposed in the positioning tube (501). The tail conductive post (8) includes a tail post (806), and the upper end of the tail post (806) is inserted into the lower end of the current-carrying tube (6). A tail conductive contact (802) and a tail first seal (803) are provided between the tail post (806) and the current-carrying tube (6). A sealing positioning seat (10) is provided at the lower end of the tail post (806), and the lower end of the core (5) is disposed on the sealing positioning seat (10).

6. The DC bushing with high-efficiency heat dissipation and multiple sealing functions according to claim 5, characterized in that: The lower end of the tail column (806) is provided with a nesting part (8062), and the lower end of the nesting part (8062) is provided with a tail flange (8063). The sealing positioning seat (10) is provided with a positioning inner hole (1002), and the lower end of the positioning inner hole (1002) is provided with a positioning groove (1003). The nesting part (8062) is inserted into the positioning inner hole (1002), and a tail second seal (804) is provided between the outer surface of the nesting part (8062) and the hole wall of the positioning inner hole (1002). The tail flange (8063) is fitted into the positioning groove (1003), and a tail third seal (805) is provided between the tail flange (8063) and the bottom of the groove of the positioning groove (1003).

7. The DC bushing with high-efficiency heat dissipation and multiple sealing functions according to claim 5, characterized in that: The sealing positioning seat (10) includes an upper positioning protrusion (1004) and a lower positioning support (1001), wherein the positioning protrusion (1004) is threaded into the positioning tube (501), and the lower end of the positioning tube (501) and the lower end of the core insulating sleeve (502) are both provided on the positioning support (1011); the tail flange (8063) is fixedly connected to the sealing positioning seat (10) through the core connecting element (807).

8. The DC bushing with high-efficiency heat dissipation and multiple sealing functions according to claim 5, characterized in that: A tail support ring (602) is provided between the lower end of the current-carrying tube (6) and the lower end of the positioning tube (501), and a tail fixing ring (603) is provided on the lower side of the tail support ring (602). The tail fixing ring (603) is fixed to the lower end of the current-carrying tube (6) through a tail fastening element (604), and a gap is left between the tail fixing ring (603) and the sealing positioning seat (10).

9. The DC bushing with high-efficiency heat dissipation and multiple sealing functions according to claim 5, characterized in that: A positioning support ring (601) is provided between the current-carrying tube (6) and the positioning tube (501); the current-carrying tube (6) includes multiple hollow tubes, and adjacent hollow tubes are connected by a built-in connecting sleeve (605); a guide cone (801) is provided at the upper end of the tail conductive post (8).

10. The DC bushing with high-efficiency heat dissipation and multiple sealing functions according to claim 1, characterized in that: The core (5) is fixedly provided with an installation flange (4) on the outside, and a through-wall flange (3) is provided on the upper side of the installation flange (4). The upper side of the through-wall flange (3) is fixedly connected to the lower end of the insulating jacket (2). The upper end of the insulating jacket (2) is provided with a metal cover plate (1), and the head conductive post (7) is fixedly connected to the metal cover plate (1). The outer side of the insulating jacket (2) is provided with a skirt.

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