CN111244857A

CN111244857A - Wall bushing

Info

Publication number: CN111244857A
Application number: CN202010197219.0A
Authority: CN
Inventors: 詹永钦; 董淑春; 金巧; 茅传强
Original assignee: GUANGXI YINHE DECOM ELECTRIC CO Ltd
Current assignee: GUANGXI YINHE DECOM ELECTRIC CO Ltd
Priority date: 2020-03-19
Filing date: 2020-03-19
Publication date: 2020-06-05

Abstract

The invention discloses a wall bushing which comprises a grounding equalizing ring, a high-voltage equalizing ring, an insulating layer, a copper terminal, a sealing groove, a flange, a fixed insert and a contact finger groove. The middle position outside the wall bushing is provided with a flange. The flange face of the wall bushing is provided with a fixed insert, and a sealing groove is formed outside the fixed insert. And an insulating layer of the wall bushing is internally provided with a grounding equalizing ring and a high-voltage equalizing ring which cover the flange surface. The number of the contact finger grooves of the grounding equalizing ring and the high-voltage equalizing ring in the insulating layer of the wall bushing is 2-4. The invention realizes the dynamic connection of the wall bushing, the creepage distance is increased by the conical cavity in the wall bushing, the corona problem is solved by the high-voltage equalizing ring and the low-voltage equalizing ring, and the electric field distribution of the wall bushing is optimized.

Description

Wall bushing

Technical Field

The invention relates to a wall bushing, and belongs to the technical field of high-voltage electrical equipment.

Background

With the continuous development of Chinese economy, the power industry has been developed greatly. High-voltage switchgear plays an increasingly active role as a means of load distribution and protection for electrical power systems. The wall bushing is widely applied to a power switch cabinet of a power supply system, and plays roles of connection transition and insulation isolation on a high-voltage power supply line passing through the power switch cabinet. An authorization notice number CN207265590U discloses a wall bushing and a switch cabinet using the wall bushing. The wall bushing comprises a bushing body, wherein a high-voltage shielding net and a low-voltage shielding net are arranged in the bushing body at intervals, at least one of the high-voltage shielding net and the low-voltage shielding net is a supporting arm shielding net, and the supporting arm shielding net comprises a shielding net body and a conductive supporting arm arranged on the shielding net body and used for supporting the supporting arm shielding net on a casting mold in a positioning manner when the wall bushing is cast. The existing literature mainly addresses fixedly connected wall bushings, but not multi-purpose bushings for dynamic connections.

Disclosure of Invention

The invention aims to provide a wall bushing which is small in size, reliable in connection and high in safety.

In order to achieve the purpose, the technical scheme of the invention is as follows: a wall bushing comprises a grounding grading ring, a high-voltage grading ring, an insulating layer, a copper terminal, a sealing groove, a flange, a fixing insert and a contact finger groove. The middle position outside the wall bushing is provided with a flange. The flange face of the wall bushing is provided with a fixed insert, and a sealing groove is formed outside the fixed insert. The insulating layer of the wall bushing is internally provided with a grounding equalizing ring and a high-voltage equalizing ring which cover the flange surface, and the wall bushing has the functions of solving the problem of electric field concentration at the joint of the flange and the partition plate and eliminating the corona phenomenon. The grounding grading ring and the high-voltage grading ring are located in the wall bushing insulating layer, and the thickness of the insulating layer between the grounding grading ring and the high-voltage grading ring is larger than 20 mm. The thickness of the insulating layer between the grounding grading ring and the outer surface of the wall bushing is larger than 3 mm. The thickness of the insulating layer between the high-voltage grading ring and the inner conical surface in the middle of the wall bushing is larger than 3 mm. The outer edge of the grounding grading ring is outwards turned, the outer edge of the high-voltage grading ring is inwards turned, and the purpose is to avoid the edge sealing and burrs at the edge from influencing the electric field grading distribution. The grounding grading ring is connected with the fixed insert and is conducted with the grounding wire through the partition plate and the cabinet body. The high-voltage grading ring is connected with the outer edge of the copper terminal. The middle of the wall bushing is an inner conical cavity, so that the conductive copper part can conveniently extend into the wall bushing to be connected with the copper terminal through the spring contact finger. The number of the contact finger grooves is 2-4, and the contact finger grooves are arranged after comprehensive calculation according to the rated current of the switch cabinet and the current-carrying capacity and temperature rise conditions of the spring contact fingers. The contact finger groove can be designed into a circular ring type groove or a watch band type groove.

The wall bushing penetrates through the partition plate, the insert on the partition plate is provided with a connecting hole at a corresponding position, and the screw penetrates through the partition plate and is screwed into the insert to fix the wall bushing on the partition plate. The wall bushing is sealed with the partition plate through an O-shaped ring in the groove on the flange surface.

The grounding grading ring and the high-voltage grading ring can be made of metal mesh materials, such as stainless steel meshes, iron wire meshes and copper wire meshes; the conductive material can also be made of a semiconductive material, such as nylon and carbon fiber or glass fiber and carbon powder which are subjected to die casting through a die.

The insulating layer is made of solid insulating material and is sealed by a sealing technology. The solid insulating material is preferably epoxy resin or ethylene propylene diene monomer.

Compared with the prior art beneficial effect: one end of the wall bushing is connected with the outer surface of the copper terminal, and the other end of the wall bushing is connected with the copper conductive piece through a spring contact finger or a watchband type contact finger in a contact finger groove in the wall bushing, so that the dynamic connection of the wall bushing is realized; the creepage distance is increased by the conical cavity in the wall bushing, the corona problem is solved by the high-voltage equalizing ring and the low-voltage equalizing ring, and the electric field distribution of the wall bushing is optimized.

Drawings

FIG. 1 is a schematic view of a wall bushing

FIG. 2 is a cross-sectional view of a wall bushing

The reference numbers illustrate: 1. the device comprises a grounding grading ring, 2, a high-voltage grading ring, 3 insulating layers, 4, a copper terminal, 5, a sealing groove, 6, a flange, 7, a fixed insert and 8, and a contact finger groove.

Detailed Description

The technical solution of the present invention is further described below with reference to the accompanying drawings.

Example 1

Fig. 1 is a perspective view of the present invention, and fig. 2 is a cross-sectional view of a wall bushing along a central axis.

As shown in figure 1, the lower part of the wall bushing is bowl-shaped, the upper part of the wall bushing is circular, the inner part of the wall bushing is an inner conical cavity, the middle part of the wall bushing is provided with a flange 6, the outer edge of the flange is provided with a sealing groove 5, and 6 or 8 inserts are uniformly distributed on the surface of the flange.

As shown in FIG. 2, the lower middle of the wall bushing has a copper terminal 4, the bottom of the wall bushing protrudes out of the insulating layer, and the middle of the bottom of the wall bushing has a mounting screw hole. The copper terminal 4 has 3 finger grooves 8. And a high-voltage equalizing ring 2 is arranged in the insulating layer 3, the outer edge of the upper part of the high-voltage equalizing ring is inwards turned, and the lower part of the high-voltage equalizing ring 2 is connected with the upper part of the copper terminal 4. And a low-voltage equalizing ring 1 is arranged in the insulating layer 3, the outer edge of the upper part of the low-voltage equalizing ring 1 is outwards turned, and the lower part of the low-voltage equalizing ring 1 is connected with a fixed insert 7. The thickness of the insulating layer between the grounding grading ring 1 and the high-voltage grading ring 2 is more than 20 mm. The thickness of the insulating layer between the grounding grading ring 1 and the outer surface of the wall bushing is larger than 3 mm. The thickness of the insulating layer between the high-voltage grading ring 2 and the inner conical surface of the wall bushing is more than 3 mm. The upper part of the inner conical surface is in a horn mouth shape and is provided with wavy lines, so that the creepage distance of the copper conductive piece when the copper conductive piece extends into the inner conical cavity is increased. The inner conical surface also plays a role in guiding the copper conductive piece.

The wall bushing penetrates through the partition board, the position, corresponding to the insert, of the partition board is provided with a connecting hole, and the screw penetrates through the partition board and is screwed into the insert to fix the wall bushing on the partition board. The wall bushing is sealed with the partition plate through an O-shaped ring in a sealing groove 5 on the surface of the flange 6. The high-voltage grading ring 2 and the grounding grading ring 1 in the wall bushing can avoid electromagnetic eddy current formed by the through holes of the partition plates, and meanwhile, the electric field distribution in the wall bushing is uniform, so that the local discharge value of the wall bushing is reduced, and the service life of a product is prolonged.

The wall bushing can be used in an inflatable switch cabinet as a connection for a bus bar to a precession disconnector. The wall bushing can also be used for connection of a busbar in the gas-filled switchgear cabinet to an external incoming line.

The invention has the beneficial effects that: one end of the wall bushing is connected with the outer surface of the copper terminal, and the other end of the wall bushing is connected with the copper conductive piece through a spring contact finger or a watchband type contact finger in a contact finger groove in the wall bushing, so that the dynamic connection of the wall bushing is realized; the creepage distance is increased by the conical cavity in the wall bushing, the corona problem is solved by the high-voltage equalizing ring and the low-voltage equalizing ring, and the electric field distribution of the wall bushing is optimized.

Claims

1. The utility model provides a wall bushing, includes ground connection equalizer ring (1), high-pressure equalizer ring (2), insulating layer (3), copper terminal (4), sealed recess (5), flange (6), fixed inserts (7) and touches and indicate recess (8), body characterized in that: a flange (6) is arranged at the middle position outside the wall bushing, a fixed insert (7) is arranged on the flange surface of the wall bushing, and a sealing groove (8) is arranged outside the fixed insert (7); the insulating layer (3) is internally provided with a grounding equalizing ring (1) and a high-voltage equalizing ring (2) which cover the surface of the flange (6); the grounding equalizing ring (1) is connected with the fixed insert (7), and the high-voltage equalizing ring (2) is connected with the outer edge of the copper terminal (4); a contact finger groove (8) is arranged in the copper terminal (4).

2. A wall bushing according to claim 1, wherein: the lower part of the wall bushing is bowl-shaped, the upper part is circular and the inner part is an inner conical cavity.

3. A wall bushing according to claim 1, wherein: the contact finger groove (8) is a circular ring type groove or a watchband type groove.

4. A wall bushing according to claim 3, wherein: the contact finger grooves (8) in the copper terminals (4) are 2-4.

5. A wall bushing according to claim 1, wherein: the solid insulating material is epoxy resin or ethylene propylene diene monomer.

6. A wall bushing according to claim 1, wherein: the thickness of the insulating layer between the grounding grading ring (1) and the high-voltage grading ring (2) is larger than 20 mm, the thickness of the insulating layer between the grounding grading ring (1) and the outer surface of the wall bushing is larger than 3 mm, and the thickness of the insulating layer between the high-voltage grading ring (2) and the inner conical surface in the middle of the wall bushing is larger than 3 mm.

7. A wall bushing according to claim 1, wherein: the grounding equalizing ring (1) and the high-voltage equalizing ring (2) are made of metal mesh materials or semi-conductive materials.

8. A wall bushing according to claim 7, wherein: the semiconductive material is nylon plus carbon fiber or glass fiber plus graphite.