Sealing structure for metal piece at oil end of bushing of dry-type transformer

Abstract

The utility model discloses a dry-type transformer bushing oil end metal piece sealing structure, which comprises a core body and a guide pipe coaxially arranged in the core body, and is characterized in that the end part of the guide pipe extends to the outer side of the core body, and a metal piece is sleeved outside the end part of the guide pipe; the end of the core body is inserted into the metal piece and abuts against the end face of an inner cavity of the metal piece, and the space between the metal piece and the core body is coated with resin glue used for bonding. An O-shaped sealing ring abutting against the core body and the metal piece is arranged on the inner side of the end of the core body. At least one spring contact finger abutting against the outer circumference of the guide pipe is embedded in the inner circumference of the metal piece located outside the tail end of the guide pipe. And a shielding ball is fixedly sleeved outside the metal piece. According to the sealing structure, the problems of core body cracking, sealing failure, shielding position displacement and the like can be reduced, and the reliability of sealing, shielding and quality of the sleeve is improved.

Description

Technical Field

[0001] The utility model relates to a metal piece sealing and shielding structure at the oil end of a dry-type transformer bushing, belonging to the technical field of bushings. Background Art

[0002] At present, the metal structure of the oil end of the dry casing is generally screwed on the root of the oil end conduit through threads and sealed in contact with the end face of the core. Since the core is made of epoxy resin and the conduit is made of metal, the two materials have different thermal expansion coefficients. When the temperature changes sharply, there is a possibility that the conduit and the core will be displaced, resulting in sealing failure or core cracking due to stress, which poses a safety hazard to the casing. Utility Model Content

[0003] The utility model aims to provide a metal sealing structure for the oil end of a dry-type transformer bushing, which can solve the problem of displacement between the conduit and the core body caused by thermal expansion and contraction.

[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0005] A metal sealing structure for the oil end of a dry-type transformer bushing comprises a core body and a conduit coaxially arranged in the core body, the end of the conduit extending to the outside of the core body, and a metal piece is disposed on the outer surface of the end of the conduit; the end of the core body is inserted into the metal piece and abuts against the end surface of the inner cavity of the metal piece, and a resin glue for bonding is coated between the metal piece and the core body;

[0006] An O-shaped sealing ring is arranged inside the end of the core body and contacts the core body and the metal part; at least one spring contact finger is embedded on the inner circumference of the metal part outside the end of the catheter and contacts the outer circumference of the catheter.

[0007] Preferably, the core is made of epoxy resin.

[0008] Preferably, the resin glue is epoxy resin glue, and the epoxy resin glue is coated on the outer circumference of the core body located in the inner cavity of the metal part.

[0009] Preferably, a sealing groove is opened on the inner side of the end of the core body, and the O-ring is embedded in the sealing groove.

[0010] Preferably, at least one annular groove is formed on the inner circumference of the metal piece located outside the end of the catheter, and the spring contact finger is embedded in the annular groove.

[0011] Preferably, a shielding ball is disposed on the outer sleeve of the metal piece, and the shielding ball is fixedly connected to the metal piece.

[0012] Preferably, the shielding ball is fixed to the metal part by a plurality of screws.

[0013] The beneficial effects of the utility model are:

[0014] In the prior art, the catheter and the metal part are fixedly connected. Therefore, when the tube expands and contracts due to heat, the metal part will change in position to a certain extent following the expansion and contraction of the tube. However, due to the different thermal expansion coefficients of the core and the tube, the change in the core is different from the change in the tube during expansion and contraction, which may cause extrusion between the core and the metal part, resulting in cracking of the core, or change in spacing, resulting in sealing failure.

[0015] The core and the metal parts are bonded together by resin glue, and the metal parts and the catheter are in non-fixed contact. Therefore, during thermal expansion and contraction, relative displacement will occur between the catheter and the metal parts. The metal parts will change position with the thermal expansion and contraction of the core, and will not be squeezed or have a changed spacing with the catheter. Therefore, the occurrence of core cracking and sealing failure caused by thermal expansion and contraction can be reduced.

[0016] In addition, the shielding ball is fixed on the metal part and will follow the metal part synchronously. Since the metal part and the core body are in a fixed relationship, the displacement of the shielding position can be reduced, thereby improving the reliability of the sleeve quality. At the same time, the extrusion of the O-ring by the metal part will not change due to thermal expansion and contraction, thereby achieving a sealing effect at the junction of the core body, the catheter and the metal part. Finally, the spring contact finger is connected to the catheter for equipotential connection and current carrying, thereby ensuring the electrical performance of the catheter. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the utility model.

[0018] The main reference numerals in the figure have the following meanings:

[0019] 1. Core; 2. Catheter; 3. Resin glue; 4. O-ring; 5. Shielding ball; 6. Metal parts; 7. Screws; 8. Spring contact finger. DETAILED DESCRIPTION

[0020] The utility model is specifically introduced below in conjunction with the accompanying drawings and embodiments.

[0021] This embodiment is a dry-type transformer bushing oil end metal sealing structure, such as Figure 1 As shown, it includes a core body 1 and a catheter 2 coaxially arranged in the core body 1, the end of the catheter 2 extends to the outside of the core body 1, and a metal piece 6 is arranged on the outer sleeve of the end of the catheter 2; the end of the core body 1 is inserted into the metal piece 6 and abuts against the end surface of the inner cavity of the metal piece 6, and a resin glue 3 for bonding is coated between the metal piece 6 and the core body 1; wherein the core body 1 is made of epoxy resin; the resin glue 3 uses epoxy resin glue 3, and the epoxy resin glue 3 is coated on the outer circumference of the core body 1 located in the inner cavity of the metal piece 6.

[0022] A sealing groove is provided on the inner side of the end of the core 1, and an O-ring 4 is placed in the sealing groove. After the metal part 6 is assembled to the end of the conduit 2, the O-ring 4 is squeezed to ensure the sealing effect between the conduit 2, the core 1 and the metal part 6. At the same time, at least one annular groove is provided on the inner circumference of the metal part 6 located outside the end of the conduit 2, and a spring contact finger 8 is embedded in the annular groove to abut against the outer circumference of the conduit 2, so that current is carried through the conduit 2, and the equipotential connection with the conduit 2 is achieved through the spring contact finger 8.

[0023] A shielding ball 5 is disposed on the metal part 6 , and the shielding ball 5 is fixed on the metal part 6 by a plurality of screws 7 .

[0024] During assembly, first, insert the spring contact finger 8 into the annular groove of the metal part 6, and install the O-ring 44 into the sealing groove of the core body 1; then, apply the epoxy resin glue 3 on the outer circumference of the end of the core body 1, and then put the metal part 6 on the end of the catheter 2, and insert the end of the core body 1 into the inner cavity of the metal part 6. After the epoxy resin glue 3 is cured, the metal part 6 and the core body 1 are fixedly connected; and after the metal part 6 is assembled to the end of the catheter 2, it will squeeze the O-ring 4, and then the sealing effect of the core body 1, the catheter 2 and the metal part 6 can be achieved; finally, the shielding ball 5 is installed on the metal part 6 with multiple screws 7.

[0025] The above structure is easy to assemble, and the current is directly carried through the conduit, and the equipotential and current are carried through the spring contact finger. Under the condition of not affecting the electrical performance, it can reduce costs and achieve economic benefits, and can also prevent virtual connection and ensure the stable operation of the bushing. The structure can also reduce problems such as core cracking, sealing failure and displacement of the shielding position, and improve the reliability of the bushing sealing, shielding and quality.

[0026] The above is only a preferred implementation of the utility model patent. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model patent. These improvements and modifications should also be regarded as the protection scope of the utility model patent.

Claims

1. A metal sealing structure for the oil end of a dry-type transformer bushing, comprising a core and a conduit coaxially arranged in the core, characterized in that: The end of the catheter extends to the outside of the core body, and a metal piece is disposed on the outer sleeve of the end of the catheter; the end of the core body is inserted into the metal piece and abuts against the end surface of the inner cavity of the metal piece, and a resin glue for bonding is coated between the metal piece and the core body; An O-shaped sealing ring is arranged inside the end of the core body and contacts the core body and the metal part; at least one spring contact finger is embedded on the inner circumference of the metal part outside the end of the catheter and contacts the outer circumference of the catheter.

2. A dry-type transformer bushing oil end metal fitting sealing structure according to claim 1, characterized in that: The core is made of epoxy resin.

3. A dry-type transformer bushing oil end metal fitting sealing structure according to claim 1, characterized in that: The resin glue is epoxy resin glue, and the epoxy resin glue is coated on the outer circumference of the core body located in the inner cavity of the metal part.

4. A dry-type transformer bushing oil end metal fitting sealing structure according to claim 1, characterized in that: A sealing groove is provided on the inner side of the end of the core body, and the O-shaped sealing ring is embedded in the sealing groove.

5. A dry-type transformer bushing oil end metal fitting sealing structure according to claim 1, characterized in that: At least one annular groove is provided on the inner circumference of the metal piece located outside the end of the catheter, and the spring contact finger is embedded in the annular groove.

6. A dry-type transformer bushing oil end metal fitting sealing structure according to claim 1, characterized in that: A shielding ball is arranged on the outer sleeve of the metal piece, and the shielding ball is fixedly connected to the metal piece.

7. A dry-type transformer bushing oil end metal fitting sealing structure according to claim 6, characterized in that: The shielding ball is fixed on the metal part by a plurality of screws.

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