Head sealing structure of dry-type cable-penetrating current-carrying oil-SF6 sleeve

Abstract

The utility model belongs to the field of power transmission and transformation, and particularly relates to a head sealing structure of a dry-type cable-penetrating current-carrying oil-SF6 sleeve in the power transmission and transformation industry. The structure comprises a head sealing flange, a locking piece and an in-gas connecting terminal, a first sealing piece is arranged between the contact surfaces of the head sealing flange and the sleeve core body to be sealed, and a second sealing piece is arranged at the corner where the head sealing flange is in contact with the central aluminum pipe and the sleeve core body; a third sealing piece is arranged on the contact face of the in-gas connecting terminal and the head sealing flange, and a fourth sealing piece is arranged on the contact face, located on the outer side of the installation groove, of the outer side of the sleeve and the head sealing flange. According to the utility model, a mode of combining plane sealing with inclined sealing and plane sealing with axial sealing is adopted, so that the problems that the conventional double-sealing structure of each connecting interface cannot ensure that the sealing rings take effect simultaneously, and the single sealing is not reliable are solved.

Description

Technical Field

[0001] This utility model relates to a sealing structure, specifically a sealing structure for the head of a dry-type cable-carrying current-carrying oil-SF6 bushing used in the power transmission and transformation industry. Background Technology

[0002] Oil-saturated SF6 bushings are an important type of bushing in the power transmission and transformation industry, and are commonly used for cable current carrying when the current is 1250A and below. Due to the special installation characteristics of this bushing (one end connects to the transformer, and the other end connects to the GIS), the SF6 gas filling the GIS has a high pressure. If the bushing is not properly sealed and SF6 gas leaks, it will not only pollute the environment, but also cause a decrease in the insulation of the GIS, which can easily lead to damage to the GIS.

[0003] Existing cable-driven current-carrying oil-SF6 bushings require multiple disassemblies and reassemblies of the bushing head due to the need to install and remove the cable terminals. The conventional double-seal structure has certain leakage risks. Therefore, ensuring a reliable seal at the bushing head is an urgent problem to be solved. Utility Model Content

[0004] The purpose of this invention is to solve the technical problem that the existing double-sealed structure of the cable-carrying current-carrying oil-SF6 bushing head has certain leakage risks after repeated disassembly and assembly, which can easily pollute the environment and cause the GIS insulation to degrade and eventually be damaged. The invention provides a dry-type cable-carrying current-carrying oil-SF6 bushing head sealing structure.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] A dry-type cable-carrying current-carrying oil-SF6 bushing head sealing structure, characterized by:

[0007] Includes head sealing flange, locking element and air connection terminal;

[0008] The head sealing flange is fitted onto the central aluminum tube of the sleeve core to be sealed through its inner hole, and its lower side abuts against the upper side of the sleeve core to be sealed.

[0009] A first sealing element is provided between the contact surface of the head sealing flange and the sleeve core to be sealed, and a second sealing element is provided at the corner where the head sealing flange contacts the central aluminum tube and the sleeve core.

[0010] The upper side of the head sealing flange is provided with an installation groove, the inner side of which is connected to the inner hole of the head sealing flange; the central aluminum tube of the locking component, which is fitted into the core of the sleeve to be sealed, is located at the installation groove, and its lower side abuts against the bottom of the groove of the head sealing flange.

[0011] A gap is provided between the outer side of the locking member and the outer side of the mounting groove; a sleeve adapted to the gap is provided on the lower side of the air-to-ground connection terminal; the sleeve on the air-to-ground connection terminal is inserted into the gap, and the lower side of the air-to-ground connection terminal abuts against the upper side of the head sealing flange.

[0012] The lower side of the gas connection terminal is provided with a mounting hole that matches the cable lead terminal on the core of the sleeve to be sealed. The gas connection terminal is fitted onto the outer peripheral surface of the cable lead terminal through the mounting hole, and the cable lead terminal is fixed on the locking member.

[0013] A third sealing element is provided on the contact surface between the gas connection terminal and the head sealing flange, and a fourth sealing element is provided on the contact surface between the outer side of the sleeve and the head sealing flange located outside the mounting groove.

[0014] Furthermore, the head sealing flange is threaded onto the central aluminum tube through its inner bore;

[0015] The locking component is a locking nut, which is threaded onto the central aluminum tube.

[0016] Furthermore, the first, second, third, and fourth seals are all sealed with O-rings.

[0017] Furthermore, the outer diameter of the head sealing flange is 135mm, and the total height of the head sealing flange and the gas connection terminal is 130mm.

[0018] The beneficial effects of this utility model are:

[0019] 1. This utility model adopts a combination of planar sealing and inclined sealing, as well as planar sealing and axial sealing, to solve the problem that conventional double-sealing structures at various connection interfaces cannot guarantee that the sealing rings will work simultaneously, and that single sealing is unreliable; and by setting an air-to-air connection terminal to plug and unplug the head sealing flange, it is easy to disassemble and assemble, and can still reliably seal even under repeated disassembly and assembly, thus avoiding leakage.

[0020] 2. This utility model solves the problem of poor insulation distance when the internal space of GIS is limited and the size of the sleeve gas connection terminal is fixed by limiting the size of the head sealing flange and the gas connection terminal.

[0021] 3. All components of this utility model are machined parts, which are easy to process, reduce the overall production cycle of the sleeve, reduce the production cost of the sleeve, greatly improve the market competitiveness of the product, and have broad market prospects. Attached Figure Description

[0022] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model;

[0023] In the diagram: 01-Sleeve core, 02-Center aluminum tube, 03-Cable lead terminal;

[0024] 1-Head sealing flange, 2-Locking element, 3-Gas connection terminal, 4-First seal, 5-Second seal, 6-Mounting groove, 7-Sleeve, 8-Third seal, 9-Fourth seal. Detailed Implementation

[0025] To make the objectives, advantages, and features of this utility model clearer, the following detailed description of a dry-type cable-carrying oil-SF6 bushing head sealing structure proposed by this utility model, in conjunction with the accompanying drawings and specific embodiments, will further clarify these points. The advantages and features of this utility model will become clearer according to the specific embodiments described below.

[0026] See Figure 1 The dry cable-carrying oil-SF6 bushing head sealing structure of this embodiment mainly includes a head sealing flange 1, a locking element 2, and an air-to-ground connection terminal 3.

[0027] I. Determination of the dimensions of the casing head structural components

[0028] Taking a 126kV / 1250A cable-carrying current-carrying oil-SF6 bushing as an example, according to IEC61639, Table 3—Standard Dimensions, the total length of the SF6 end is limited to 520mm, and the inner diameter is only about 300mm. The diameter of the gas-connected terminal 3 is 99mm, and the terminal height is ≥30mm. Therefore, to ensure the insulation distance, the size of the head structure should not be too large, with a total height of 130mm and an outer diameter of 135mm, which ensures both insulation distance and assembly space. The head structure consists of two parts: 1. Head sealing flange 1; 2. Gas-connected terminal 3.

[0029] II. Selection of sealing surface location and determination of sealing structure

[0030] A planar seal and a bevel seal are provided between the head sealing flange 1 and the sleeve core 01 to be sealed; a planar seal and an axial seal are provided between the gas connection terminal 3 and the head sealing flange 1; this ensures two seals at different positions on each interface path; effectively preventing leakage between the gas connection terminal 3 and the head sealing flange 1, between the head sealing flange 1 and the sleeve core 01 to be sealed, and between the sleeve core 01 to be sealed and its upper central aluminum tube 02.

[0031] The aforementioned planar seal, axial seal, and bevel seal all use O-rings for sealing.

[0032] III. Determining the fit and disassembly / assembly methods between components

[0033] The head sealing flange 1 is threaded onto the central aluminum tube 02 of the sleeve core 01 to be sealed via its inner hole, with its lower side abutting against the upper side of the sleeve core 01 to be sealed. A first sealing element 4, i.e., the aforementioned first planar seal, is provided between the contact surfaces of the head sealing flange 1 and the sleeve core 01 to be sealed. A second sealing element 5, i.e., the aforementioned inclined seal, is provided at the corner where the head sealing flange 1 contacts the central aluminum tube 02 and the sleeve core 01. An installation groove 6 is provided on the upper side of the head sealing flange 1, and the inner side of the installation groove 6 is connected to the inner hole of the head sealing flange 1. The locking element 2 is a locking nut, which is threaded onto the sleeve core 01. The central aluminum tube 02 of the sleeve core 01 to be sealed is located at the mounting groove 6, and its lower side abuts against the bottom of the mounting groove 6 of the head sealing flange 1. A gap is provided between the outer side of the locking member 2 and the outer side of the mounting groove 6. A sleeve 7 adapted to the gap is provided on the lower side of the gas connection terminal 3. The sleeve 7 on the gas connection terminal 3 is inserted into the gap, and the lower side of the gas connection terminal 3 abuts against the upper side of the head sealing flange 1. A mounting hole adapted to the cable lead terminal 03 on the lower side of the gas connection terminal 3 is provided, and the gas connection terminal 3 is fitted onto the outer circumferential surface of the cable lead terminal 03 through the mounting hole. The cable lead terminal 03 is fixed on the locking member 2. The specific fixing method is not specifically limited in this embodiment, as long as it meets the relevant technical requirements. A third sealing element 8, namely the aforementioned second planar seal, is provided on the contact surface between the gas connection terminal 3 and the head sealing flange 1; a fourth sealing element 9, namely the aforementioned axial seal, is provided on the contact surface between the outer side of the sleeve 7 and the head sealing flange 1 located outside the mounting groove 6.

Claims

1. A dry-type cable-carrying current-carrying oil-SF6 bushing head sealing structure, characterized in that: Includes a head sealing flange (1), a locking element (2), and an air-to-ground connection terminal (3); The head sealing flange (1) is fitted onto the central aluminum tube (02) of the sleeve core (01) to be sealed through its inner hole, and its lower side abuts against the upper side of the sleeve core (01) to be sealed. A first sealing element (4) is provided between the contact surface of the head sealing flange (1) and the sleeve core (01) to be sealed, and a second sealing element (5) is provided at the corner where the head sealing flange (1) contacts the central aluminum tube (02) and the sleeve core (01). The upper side of the head sealing flange (1) is provided with an installation groove (6), the inner side of which is connected to the inner hole of the head sealing flange (1); the locking member (2) is fitted into the central aluminum tube (02) of the sleeve core (01) to be sealed, which is located in the installation groove (6), and its lower side abuts against the bottom of the groove of the head sealing flange (1) located in the installation groove (6); A gap is provided between the outer side of the locking member (2) and the outer side of the mounting groove (6); a sleeve (7) adapted to the gap is provided on the lower side of the gas connection terminal (3); the sleeve (7) on the gas connection terminal (3) is inserted into the gap, and the lower side of the gas connection terminal (3) abuts against the upper side of the head sealing flange (1). The lower side of the gas connection terminal (3) is provided with an installation hole that is compatible with the cable lead terminal (03) on the core body (01) to be sealed. The gas connection terminal (3) is fitted onto the outer circumferential surface of the cable lead terminal (03) through the installation hole. The cable lead terminal (03) is fixed on the locking member (2). A third sealing element (8) is provided on the contact surface between the gas connection terminal (3) and the head sealing flange (1), and a fourth sealing element (9) is provided on the contact surface between the outer side of the sleeve (7) and the head sealing flange (1) located outside the mounting groove (6).

2. The dry-type cable-carrying current-carrying oil-SF6 bushing head sealing structure according to claim 1, characterized in that: The head sealing flange (1) is threaded onto the central aluminum tube (02) through its inner hole; The locking component (2) is a locking nut, which is threaded onto the central aluminum tube (02).

3. The dry-type cable-carrying current-carrying oil-SF6 bushing head sealing structure according to claim 2, characterized in that: The first seal (4), the second seal (5), the third seal (8) and the fourth seal (9) all use O-rings.

4. The dry-type cable-carrying current-carrying oil-SF6 bushing head sealing structure according to any one of claims 1-3, characterized in that: The outer diameter of the head sealing flange (1) is 135mm, and the total height of the head sealing flange (1) and the gas connection terminal (3) is 130mm.

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