Insulated terminal structure and capacitor

Abstract

The application relates to an insulating terminal structure and a capacitor, and the insulating terminal structure comprises a capacitor end cover, a conductive rod, an insulator and an insulating ring, the conductive rod, the insulator and the insulating ring are coaxially arranged; the conductive rod and the insulating ring are both arranged below the capacitor end cover, the upper end of the conductive rod extends above the capacitor end cover, the capacitor end cover is provided with a via hole for the conductive rod to pass through; the insulator is arranged above the capacitor end cover, the lower end of the insulator passes through the via hole and is threadedly connected with the conductive rod; when the insulator is threadedly connected with the conductive rod, the conductive rod and the capacitor end cover cooperatively clamp the insulating ring. The application does not have the problem of contact resistance, and can conveniently dismount and replace the insulator and other components.

Description

Technical Field

[0001] The invention relates to the field of capacitor technology, specifically to an insulating terminal structure and a capacitor. Background Technology

[0002] Large, hermetically sealed capacitors are widely used in industrial drives, rail transportation, and smart grids. These capacitors typically feature insulated terminal structures that not only need to isolate external moisture and dust, ensuring reliable isolation between the internal dielectric and the external environment, but also serve dual functions of mechanical and electrical connection. On one hand, the insulated terminals should be securely locked to the capacitor end caps or housing to prevent loosening under conditions such as vibration and temperature changes; on the other hand, they should ensure good conductivity and low contact resistance to reduce current-carrying heat generation, thereby guaranteeing the overall performance and long-term operational reliability of the capacitor product.

[0003] Currently, the insulation terminal structure of large sealed capacitors in the industry mainly follows two technical approaches: Technical route one: such as Figure 1 As shown, the insulating terminal consists of main components such as an insulator 30', an insulating ring 40', a conductive rod 20', a copper nut 70', and several sealing components with different structures. The conductive rod 20' needs to pass through the end cover 10' to connect the internal and external electrical connection components of the capacitor. During installation, in addition to the sealing fit, the conductive rod 20' is also threadedly connected to the copper nut 70' on the outside of the capacitor end cover 10', thereby pressing and fixing the insulator to the capacitor end cover 10'. However, under operating conditions such as temperature shock, thermal cycling, or vibration shock, the preload of the threaded connection is easily weakened, and the copper nut 70' comes into contact with the external connection component, resulting in a significant increase in contact resistance, which in turn causes local heating. In severe cases, it can lead to local arcing and erosion, affecting the operational reliability and service life of the capacitor.

[0004] Technical route two: such as Figure 2 As shown, its general structure is the same as technical route one, except that the conductive rod 20' and copper nut 70' in technical route one are designed as an integral structure (directly welded and fixed), so as to eliminate or reduce the intermediate transition threaded contact surface between the conductive rod 20' and copper nut 70', thereby improving the stability of the electrical connection. However, after the integral structure is installed, the insulator and other external insulating components cannot be disassembled without damage. Once the insulator or related external components are damaged, it will be difficult to maintain or replace them; if the damage is severe, the entire capacitor can only be scrapped, resulting in poor product maintainability. Summary of the Invention

[0005] In view of the problems existing in the prior art, the purpose of the invention is to provide an insulating terminal structure and capacitor that does not have the problem of contact resistance and can facilitate the disassembly and replacement of insulators and other components.

[0006] To achieve the above objectives, the invention adopts the following technical solution: An insulating terminal structure includes a capacitor end cap, a conductive rod, an insulator, and an insulating ring, wherein the conductive rod, insulator, and insulating ring are coaxially arranged; the conductive rod and the insulating ring are both positioned below the capacitor end cap, with the upper end of the conductive rod extending above the capacitor end cap, and the capacitor end cap having a through hole for the conductive rod to pass through; the insulator is positioned above the capacitor end cap, with the lower end of the insulator passing through the through hole and threadedly connected to the conductive rod; when the insulator and the conductive rod are threadedly connected, the conductive rod and the capacitor end cap cooperate to clamp the insulating ring.

[0007] After the above settings are implemented, the creepage distance and insulation strength between the conductive rod and the capacitor end cover can be increased by adding insulating rings and insulators. The insulators also provide insulation protection to the outside of the capacitor. By threading the insulators to the conductive rods, the various components can be locked and secured, making installation and removal convenient and quick.

[0008] The insulator has a first through hole that matches the shape of the conductive rod. The lower end of the first through hole has an internal thread, and the outer wall of the conductive rod has an external thread that matches the internal thread. This configuration is simple.

[0009] The internal thread is formed on the wall of the first through hole; or, an insert is embedded at the lower end of the first through hole, and the internal thread is disposed on the insert.

[0010] The outer wall of the insert is provided with a friction part to enhance the bonding force between the insert and the insulator. This arrangement ensures that the insert and the insulator can be tightly bonded, and that the insulator is reliably locked onto the conductive rod.

[0011] The friction part is knurled, grooved, or raised ring. This type of friction part is simple and easy to design.

[0012] It also includes a sealing ring and a sealing gasket. The conductive rod, insulator, insulating ring, sealing ring, and sealing gasket are coaxially arranged. The sealing gasket is placed below the capacitor end cap, and the sealing ring is placed above the capacitor end cap. The insulator cooperates with the capacitor end cap to clamp the sealing ring, and the insulator cooperates with the conductive rod to clamp the sealing gasket. When the insulator and the conductive rod are threaded together, the conductive rod cooperates with the insulating ring to clamp the sealing gasket. The sealing gasket and sealing ring provide a sealing function, and the sealing gasket also acts as a buffer.

[0013] The lower end of the conductive rod is provided with an end plate, which cooperates with the capacitor end cap to clamp the insulating ring, the end plate and the insulating ring to clamp the sealing gasket, and the end plate and the insulator to clamp the sealing gasket. The end plate is provided to improve sealing reliability and ensure reliable support for the insulating ring.

[0014] The insulating ring has a positioning groove that matches the shape of the end plate, and the end plate is inserted into the positioning groove. This arrangement reliably positions the insulating ring to ensure a constant creepage distance and insulation strength between the conductive rod and the capacitor end cap.

[0015] The sealing gasket includes an integrally formed body and a step. The step is located on the outer periphery of the body and is arranged circumferentially. The insulating ring has a second through hole for the conductive rod to pass through. A pressure ring is arranged circumferentially in the second through hole, and the pressure ring cooperates with the conductive rod to clamp the step. The insulator cooperates with the conductive rod to clamp the body. This arrangement ensures reliable sealing.

[0016] The lower end of the insulator is shaped to match the through hole; a pressure plate is provided on the outer wall of the insulator along its circumference, and the pressure plate is in stop-fit ​​with the through hole; a mounting groove is provided on the pressure plate along its circumference, and the sealing ring is placed in the mounting groove. This arrangement ensures a constant creepage distance and insulation strength between the conductive rod and the capacitor end cap, as well as reliable sealing.

[0017] The invention also discloses a capacitor that employs the aforementioned insulated terminal structure.

[0018] By adopting the above scheme, the creepage distance and insulation strength between the conductive rod and the capacitor end cover can be increased by setting insulating rings and insulators. The insulators also provide insulation protection on the outside of the capacitor. Sealing gaskets and sealing rings provide sealing, and the sealing gaskets also act as buffers. By threading the insulators to the conductive rods, the components are locked and secured, making installation and removal convenient and quick. Furthermore, this invention eliminates the need for copper nuts, avoiding contact resistance issues and improving safety and reliability. When the insulator is damaged due to aging, mechanical damage, or other abnormal reasons during use, and other parts of the capacitor are normal, it can be easily removed and replaced simply by unscrewing the insulator from the conductive rod. The replaced capacitor can continue to be used normally, avoiding the scrapping of the entire capacitor due to partial damage to the insulator, and significantly reducing the total life-cycle maintenance cost of the capacitor. Attached Figure Description

[0019] Figure 1 A schematic diagram of existing technology (Technical Route 1); Figure 2 A schematic diagram of existing technology (Technical Route 2); Figure 3 This is a schematic diagram of Example 1; Figure 4 This is a schematic diagram from another perspective of Embodiment 1; Figure 5 This is an exploded view of Example 1; Figure 6 This is an exploded view of Embodiment 1 from another perspective; Figure 7 This is a cross-sectional view of Embodiment 1; Figure 8 This is a schematic diagram of the conductive rod in Example 1; Figure 9 This is a schematic diagram of the insulator in Example 1; Figure 10 This is a schematic diagram of the insulating ring in Example 1; Figure 11 This is a schematic diagram of the sealing gasket in Example 1; Figure 12 This is a cross-sectional view of Example 2; Figure 13 This is a schematic diagram of the insulator in Example 2; Figure 14 This is a schematic diagram of the insert in Example 2.

[0020] Explanation of key figure labels: Capacitor end cap 10; Through hole 11; Conductive rod 20; end plate 21; external thread 22; Insulator 30; First through hole 31; Internal thread 32; Pressure plate 33; Mounting groove 34; Insert 35; Friction part 36; Insulating ring 40; second through hole 41; positioning groove 42; pressure ring 43; 50 sealing ring; Sealing gasket 60; Through hole 61; Body 62; Step 63; Copper nut 70. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0022] Example 1 like Figure 3-11 As shown, this embodiment discloses an insulating terminal structure, which includes a capacitor end cap 10, a conductive rod 20, an insulator 30, an insulating ring 40, a sealing ring 50, and a sealing gasket 60. In this embodiment, the conductive rod 20, the insulator 30, the insulating ring 40, the sealing ring 50, and the sealing gasket 60 are coaxially arranged. The insulating ring 40 has a second through hole 41 for the conductive rod 20 to pass through. The capacitor end cap 10 has a through hole 11 for the conductive rod 20 to pass through. The sealing gasket 60 has a through hole 61 for the conductive rod 20 to pass through. The insulator 30 has a first through hole 31 for the conductive rod 20 to pass through.

[0023] The conductive rod 20, insulating ring 40, and sealing gasket 60 are all positioned below the capacitor end cap 10 (corresponding to the inside of the capacitor). The lower end of the conductive rod 20 is provided with an end plate 21 (integratedly formed or welded). The end plate 21 is preferably circular, and its diameter is preferably larger than the diameter of the through hole 11. The upper end of the conductive rod 20 extends through the hole 11 to the top of the capacitor end cap 10 (corresponding to the outside of the capacitor).

[0024] The insulator 30 and sealing ring 50 are positioned above the capacitor end cover 10, with the lower end of the insulator 30 passing through the through hole 11. The shape of the lower end of the insulator 30 matches the hole shape of the through hole 11, while the hole shape of the first through hole 31 matches the conductive rod 20. This ensures that the positions of the insulator 30 and the conductive rod 20 are fixed relative to the capacitor end cover 10 in the assembled insulating terminal structure. An internal thread 32 is formed at the lower end of the inner wall of the first through hole 31, and an external thread 22 is provided on the outer wall of the conductive rod 20. The insulator 30 is threaded through the engagement of the internal thread 32 and the external thread 22. To prevent the insulator 30 from being excessively screwed into the through hole 11, a pressure plate 33 is provided on the outer wall of the insulator 30 along its circumference, which engages with the through hole 11. The pressure table 33 is provided with a mounting groove 34 arranged along its circumference. The sealing ring 50 is placed in the mounting groove 34. When the insulator 30 is tightened, the sealing ring 50 is pressed between the pressure table 33 and the capacitor end cover 10, thereby sealing the gap between the two.

[0025] When the insulator 30 is tightened, the end plate 21 of the conductive rod 20 cooperates with the capacitor end cover 10 to clamp the insulating ring 40, thereby securing the insulating ring 40. To ensure the stability of the insulating ring 40 in the assembled state, the lower end opening of the second through hole 41 is enlarged to form a positioning groove 42 that matches the shape of the end plate 21, so that the end plate 21 is inserted into the positioning groove 42, thereby positioning the insulating ring 40.

[0026] When the insulator 30 is tightened, the lower end of the insulator 30 engages with the end plate 21 of the conductive rod 20 to clamp the sealing gasket 60. Simultaneously, the insulating ring 40 also engages with the end plate 21 of the conductive rod 20 to clamp the sealing gasket 60. Furthermore, the sealing gasket 60 includes an integrally formed body 62 and a step 63. The step 63 is located on the outer periphery of the body 62 and is arranged circumferentially along the body 62. The bottom surface of the step 63 is flush with the bottom surface of the body 62 and abuts against the upper surface of the end plate 21 of the conductive rod 20. A pressure ring 43 is provided in the second through hole 41, arranged circumferentially. This pressure ring 43 engages with the end plate 21 of the conductive rod 20 to clamp the step 63. The lower end of the insulator 30 engages with the end plate 21 of the conductive rod 20 to clamp the body 62. This arrangement ensures reliable sealing.

[0027] After the insulator 30 is tightened, the upper end of the conductive rod 20 extends out of the insulator 30 to ensure that the conductive rod 20 can be electrically connected to the external devices of the capacitor.

[0028] Example 2 like Figure 12-14 As shown, the difference between this embodiment and Embodiment 1 is that an insert 35 is embedded at the lower end of the first through hole 31, and an internal thread 32 is provided on the insert 35. The insert 35 and the insulator 30 are injection molded or cast together to ensure a reliable connection between the two. A friction part 36 can be provided on the outer wall of the insert 35 to improve the bonding force between the insert 35 and the insulator 30. The friction part 36 can be knurled, grooved, or raised ring, etc. By setting the insert 35, the accuracy of the internal thread 32 can be better guaranteed, which helps to improve the reliability of the connection.

[0029] The key to this invention lies in the fact that by setting the insulating ring 40 and the insulator 30, the creepage distance and insulation strength between the conductive rod 20 and the capacitor end cover 10 can be increased. The insulator 30 also provides insulation protection on the outside of the capacitor. The sealing gasket 60 and the sealing ring 50 provide a sealing function, and the sealing gasket 60 also acts as a buffer. By making the insulator 30 and the conductive rod 20 threadedly connected, the components are locked and secured, making installation and removal convenient and quick. Since there is no need for a copper nut, there is no contact resistance problem, resulting in better safety and reliability. When the insulator 30 is damaged due to aging, mechanical damage, or other abnormal reasons during use, and the other parts of the capacitor are normal, it can be removed and replaced simply by unscrewing the insulator 30 from the conductive rod 20. The replaced capacitor can continue to be used normally, avoiding the scrapping of the entire capacitor due to partial damage to the insulator 30, and significantly reducing the maintenance cost of the capacitor throughout its entire life cycle.

[0030] The above description is merely an embodiment of the invention and does not limit the technical scope of the invention in any way. Therefore, any minor modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the invention shall still fall within the scope of the invention's technical solution.

Claims

1. An insulating terminal structure, characterized in that: The device includes a capacitor end cap, a conductive rod, an insulator, and an insulating ring, all arranged coaxially. The conductive rod and insulating ring are both positioned below the capacitor end cap, with the upper end of the conductive rod extending above the end cap. The capacitor end cap has a through hole through which the conductive rod passes. The insulator is positioned above the end cap, with its lower end passing through the through hole and threadedly connected to the conductive rod. When the insulator and conductive rod are threadedly connected, the conductive rod and the capacitor end cap cooperate to clamp the insulating ring.

2. The insulating terminal structure according to claim 1, characterized in that: The insulator is provided with a first through hole that matches the shape of the conductive rod. The lower end of the first through hole is provided with an internal thread, and the outer wall of the conductive rod is provided with an external thread that matches the internal thread. The internal thread is formed on the wall of the first through hole; or, an insert is embedded at the lower end of the first through hole, and the internal thread is disposed on the insert.

3. The insulating terminal structure according to claim 2, characterized in that: The outer wall of the insert is provided with a friction part for enhancing the bonding force between the insert and the insulator.

4. An insulating terminal structure according to claim 3, characterized in that: The friction part is knurled, grooved, or raised.

5. An insulating terminal structure according to claim 1, characterized in that: It also includes a sealing ring and a sealing gasket. The conductive rod, insulator, insulating ring, sealing ring and sealing gasket are arranged coaxially. The sealing gasket is placed below the capacitor end cover and the sealing ring is placed above the capacitor end cover. The insulator and the capacitor end cover cooperate to clamp the sealing ring and the insulator and the conductive rod cooperate to clamp the sealing gasket. When the insulator and the conductive rod are threaded together, the conductive rod and the insulating ring cooperate to clamp the sealing gasket.

6. An insulating terminal structure according to claim 5, characterized in that: The lower end of the conductive rod is provided with an end plate, which cooperates with the capacitor end cap to clamp the insulating ring, the end plate and the insulating ring to clamp the sealing gasket, and the end plate and the insulator to clamp the sealing gasket.

7. An insulating terminal structure according to claim 6, characterized in that: The insulating ring is provided with a positioning groove that matches the shape of the end plate, and the end plate is inserted into the positioning groove.

8. An insulating terminal structure according to claim 5, characterized in that: The sealing gasket includes an integrally formed body and a step. The step is located on the outer periphery of the body and is arranged along the circumference of the body. The insulating ring is provided with a second through hole for the conductive rod to pass through. A pressure ring is provided in the second through hole and is arranged along its circumference. The pressure ring cooperates with the conductive rod to clamp the step. The insulator cooperates with the conductive rod to clamp the body.

9. An insulating terminal structure according to claim 5, characterized in that: The lower end of the insulator is shaped to match the hole shape of the through hole; the outer wall of the insulator is provided with a pressure plate arranged circumferentially thereon, and the pressure plate is in stop fit with the through hole; the pressure plate is provided with a mounting groove arranged circumferentially thereon, and the sealing ring is placed in the mounting groove.

10. A capacitor, characterized in that: The insulating terminal structure described in any one of claims 1-9 is adopted.

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