CN112927893A

CN112927893A - Terminal assembly, method for mounting terminal assembly and transformer bushing

Info

Publication number: CN112927893A
Application number: CN202110259669.2A
Authority: CN
Inventors: 孙中源; 孙略; 高俊
Original assignee: Jiangsu Shenma Electric Power Co Ltd
Current assignee: Jiangsu Shenma Electric Power Co Ltd
Priority date: 2021-03-10
Filing date: 2021-03-10
Publication date: 2021-06-08

Abstract

The application discloses end assembly, be used for transformer bushing, including setting gradually at the terminal first lock nut of central conducting rod, the installation end cover, second lock nut, through screw thread locking between central conducting rod and the three, through cementing end cover fixed connection between insulating tube and installation end cover in the oil, can prevent the rotation between central conducting rod and installation end cover, and can make the experimental tap on the electric capacity core correspond with the mounting hole position through rotatory installation end cover, can not take place the dislocation, in addition, first lock nut and second lock nut and installation end cover between the sealing washer, owing to avoided the setting of pin, can not lead to the damage of sealing washer. The application also discloses a method for installing the terminal assembly and a transformer bushing comprising the terminal assembly.

Description

Terminal assembly, method for mounting terminal assembly and transformer bushing

Technical Field

The application relates to the field of power transmission and transformation insulating equipment, in particular to a terminal assembly, a method for installing the terminal assembly and a transformer bushing.

Background

The power transformer is one of the most important and expensive critical power devices in the power system, and the transformer bushing is one of the critical parts of the transformer, and the electrical performance of the transformer bushing directly affects the operational reliability and safety of the transformer.

The central conducting rod of the existing composite sleeve is generally in threaded connection with the bottom mounting end cover, lacks of tightening force and is easy to loosen in use, so that the central conducting rod is rotated. At present, the rotation problem is solved by additionally installing an anti-rotation pin, but because of the axial seal between the central conducting rod and the cementing end cover, a pin hole easily scratches a sealing ring to cause sealing failure, and test taps on the capacitor core are easily dislocated.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide an end component, a method for mounting the end component and a transformer bushing, wherein the end component comprises a first clamping nut, a mounting end cover and a second clamping nut which are sequentially arranged at the end of a central conducting rod, the central conducting rod and the mounting end cover are locked through threads, an insulating tube in oil and the mounting end cover are fixedly connected through a cementing end cover, the rotation between the central conducting rod and the mounting end cover can be prevented, a test tap on a capacitor core can correspond to the position of a mounting hole through rotating the mounting end cover, and dislocation can not occur.

In order to achieve the purpose, the technical means adopted by the invention are as follows: a terminal component is used for a transformer bushing, the transformer bushing comprises an insulating tube in oil and a capacitor core penetrating through the insulating tube in oil, the capacitor core comprises a central conducting rod, and the terminal component comprises a cementing end cover, an installation end cover, a first clamping nut and a second clamping nut; one end of the cementing end cover is provided with a fixing groove for fixing the insulating tube in the oil, the cementing end cover is also provided with a first through hole for accommodating the mounting end cover, and the end of the cementing end cover far away from the insulating tube in the oil is matched with and hermetically connected with the end of the mounting end cover close to the insulating tube in the oil in shape; the installation end cover is provided with a second through hole coaxial with the first through hole for the central conducting rod to pass through, the first clamping nut, the installation end cover and the second clamping nut are sequentially fixedly sleeved at the end part of the central conducting rod, and the first clamping nut and the second clamping nut clamp and tightly install the end cover. Can prevent the rotation between central conducting rod and the installation end cover after through screw locking between central conducting rod and the first lock nut, installation end cover, the second lock nut three, and can make the test on the electric capacity core take a percentage and correspond with the mounting hole position through rotatory installation end cover, can not take place the dislocation, in addition, first lock nut and second lock nut and the installation end cover between the sealing washer, owing to not set up the pin, can not lead to the damage of sealing washer.

Preferably, the installation end cover includes connecting portion and installation department, and connecting portion and installation department are the hollow cylinder of coaxial setting, make the whole T style of calligraphy setting that is of installation end cover, and connecting portion are used for cup jointing central conducting rod, and the installation department is used for with mucilage binding end cover fixed connection. The installation part is arranged, so that the installation end cover can be better connected with the cementing end cover, and the stability of the whole structure of the tail end assembly is kept.

Preferably, the one end that insulating tube in the oil was kept away from to the mucilage binding end cover sets up the mounting groove, and the mounting groove matches and passes through fastener fixed connection with the installation department. The mounting groove is matched with the mounting part in shape, so that the mounting groove is convenient to assemble and disassemble, and can be difficult to fall off in the operation process through the fixed connection of the fastening piece, and the damage to equipment is avoided.

Preferably, the end of the mounting end cap remote from the oil-in-oil insulating tube is provided with a groove in which the second clamping nut is placed. Set up the recess on the installation end cover and supply second lock nut to place for second lock nut holds in the inside of installation end cover, has avoided second lock nut to bulge outside whole terminal assembly, has improved terminal assembly's whole mechanical strength, and screw thread mating connection more can exert its and tight effect.

Preferably, the outer circumference of the first jam nut is provided with at least one first jam groove for installation and tightening. The arrangement of the first tightening groove facilitates the assembly and the reverse rotation of the first tightening nut.

Preferably, the second clamping nut is provided with at least one second clamping groove for mounting and clamping on the end face away from the oil insulating tube. The arrangement of the second tightening groove facilitates the assembly of the second tightening nut.

Preferably, a first sealing ring is arranged at the joint of the end face of the insulating tube in the oil and the cementing end cover. The first seal ring can prevent the insulating oil from leaking from the bottom of the insulating tube in the oil.

Preferably, a second sealing ring is arranged between the first clamping nut and the mounting end cover, and a third sealing ring is arranged between the second clamping nut and the mounting end cover. The setting of second sealing washer can prevent insulating oil along the seepage of central conducting rod, and the third sealing washer plays double seal's effect, has strengthened terminal assembly's whole sealed effect.

The invention also provides a method for installing the terminal assembly, which comprises the following steps: step a: cementing and fixing the insulating tube in the oil and the cementing end cover; step b: extending the central conducting rod out of one end of the insulating tube in oil, and rotating the first clamping nut to the end part of the central conducting rod; step c: mounting the mounting end cap to the end of the central conductor bar adjacent to the first draw-down nut; step d: reversely rotating the first clamping nut to clamp the first clamping nut and the mounting end cover; step e: installing and fixing the central conducting rod connected with the first clamping nut and the installation end cover and the cementing end cover through a fastener; step f: the second draw nut is rotated onto the end of the center conductor bar to draw it into close proximity with the mounting end cap.

According to another aspect of the present invention, a transformer bushing is provided that employs any of the above-described terminal assemblies.

The beneficial effect of this application is: center conducting rod and first lock nut, the installation end cover, through screw thread locking between the second lock nut three, through cementing end cover fixed connection between insulating tube and installation end cover in the oil, can prevent the rotation between center conducting rod and installation end cover, and can make the experimental tap on the electric capacity core correspond with the mounting hole position through rotatory installation end cover, can not take place the dislocation, in addition, this end subassembly need not to set up the pin on center conducting rod, has avoided the damage of sealing washer.

Drawings

FIG. 1 is a schematic structural diagram of a tip assembly 100 according to a first embodiment of the present invention;

FIG. 2 is a schematic view of the assembly of the tip assembly 100 according to the first embodiment of the present invention;

FIG. 3 is a schematic plan view of a first jam nut 130 according to a first embodiment of the invention;

FIG. 4 is a schematic plan view of a second jam nut 140 in accordance with a first embodiment of the invention;

fig. 5 is a schematic structural diagram of a transformer bushing 1000 according to a third embodiment of the present invention.

Detailed Description

As required, detailed embodiments of the present invention are disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed manner, including employing various features disclosed herein in combination with features that may not be explicitly disclosed herein.

The first embodiment is as follows:

as shown in fig. 1 and 2, the present embodiment provides an end assembly 100 for a transformer bushing, the transformer bushing includes an oil-in-oil insulating tube 1100 and a capacitor core disposed in the oil-in-oil insulating tube 1100, the capacitor core includes a central conductive rod 1200, and the end assembly 100 includes a glue end cap 110, a mounting end cap 120, a first clamping nut 130, and a second clamping nut 140. One end of the cementing end cover 110 is provided with a fixing groove 112 for fixing the insulating tube 1100 in oil, the cementing end cover 110 is also provided with a first through hole 111 for accommodating the mounting end cover 120, and the end of the cementing end cover 110 far away from the insulating tube 1100 in oil is matched with and hermetically connected with the end of the mounting end cover 120 close to the insulating tube 1100 in oil in shape; the mounting end cap 120 is provided with a second through hole coaxial with the first through hole 111 for the central conducting rod 1200 to pass through, the first clamping nut 130, the mounting end cap 120 and the second clamping nut 140 are sequentially fixedly sleeved at the end of the central conducting rod 1200, and the first clamping nut 130 and the second clamping nut 140 clamp and tightly mount the mounting end cap 120. The rotation between the central conducting rod 1200 and the installation end cover 120 can be prevented after the central conducting rod 130 and the first clamping nut 130 are locked by the threads, the installation end cover 120 is installed, the second clamping nut 140 can enable the test tap on the capacitor core to correspond to the installation hole position through rotating the installation end cover 120, the dislocation cannot occur, in addition, the sealing rings between the first clamping nut 130 and the second clamping nut 140 and the installation end cover 120 are not provided with pins, and the damage of the sealing rings cannot be caused.

Specifically, the cementing end cover 110 is fixedly connected to one end of the insulating tube 1100 in oil, the installation end cover 120 is sleeved on one end of the central conducting rod 1200 and is fixed to one end of the cementing end cover 110 away from the insulating tube 1100 in oil, and the two ends of the installation end cover 120 are respectively provided with the first clamping nut 130 and the second clamping nut 140 to clamp the installation end cover 120, that is, the first clamping nut 130, the installation end cover 120 and the second clamping nut 140 are sequentially sleeved on the periphery of the central conducting rod 1200, so as to fixedly connect the central conducting rod 1200 to the installation end cover 120.

In this embodiment, the mounting end cover 120 includes a connecting portion 121 and a mounting portion 122, the connecting portion 121 and the mounting portion 122 are hollow cylinders coaxially disposed, so that the mounting end cover 120 is integrally disposed in a T shape, the connecting portion 121 is configured to be sleeved with the central conductive rod 1200, and the mounting portion 122 is configured to be fixedly connected to the cementing end cover 110. Specifically, in this embodiment, the connection portion 121 is a hollow cylinder, the outer circumference of the end portion of the central conductive rod 1200 located at the terminal assembly 100 is provided with an external thread, the inner diameter of the connection portion 121 matches the outer diameter of the central conductive rod 120, and the inner wall of the connection portion 121 is provided with an internal thread, so that the connection portion 121 and the central conductive rod 1200 are connected by thread assembly. Meanwhile, the outer circumferential surface of the connecting portion 121 extends outward in the radial direction of the mounting end cover 120 to form a mounting portion 122, the width of the mounting portion 122 is smaller than the width of the connecting portion 121 in the axial direction of the mounting end cover 120, so that a step is formed between the connecting portion 121 and the mounting portion 122, and the mounting portion 122 is located at one end of the connecting portion 121 far away from the oil insulating tube 1100, so that the mounting end cover 120 is T-shaped as a whole. The mounting portion 122 is provided to allow the mounting end cap 120 to be better coupled to the glue end cap 110, maintaining the overall structural stability of the tip assembly 100.

Further, one end of the installation end cover 120, which is far away from the oil-in-oil insulating tube 1100, is provided with a groove 124, the second clamping nut 140 is placed in the groove 124 after being sleeved on the central conducting rod 1200, so that the second clamping nut 140 is accommodated in the installation end cover 120, and the first clamping nut 130, the installation end cover 120 and the second clamping nut 140 form a whole in the axial direction of the transformer bushing, thereby avoiding the second clamping nut 140 from protruding out of the whole terminal assembly 100, and improving the overall mechanical strength of the terminal assembly 100.

In the present embodiment, the connecting portion 121 and the mounting portion 122 are hollow cylinders coaxially disposed. In other embodiments, connecting portion and installation department also can be other hollow cylinder of coaxial setting, for example prismatic, ladder post, square column, triangular prism etc. as long as guarantee its hollow coaxial can supply central conducting rod to pass, and the mucilage binding end cover can with the installation end cover phase-match can.

In the present embodiment, the connecting portion 121 of the mounting end cap 120 is integrally formed with the mounting portion 122, so that connecting gaps are reduced, and the risk of leakage is reduced.

In other embodiments, the connecting portion and the mounting portion may be separate structures, but the connection strength and the sealing between the connecting portion and the mounting portion are ensured, for example, by welding, and additionally installing a sealing ring, so as to ensure the sealing performance of the entire terminal assembly.

In this embodiment, a fixing groove 112 is disposed at one end of the cementing end cover 110 close to the insulating tube 1200 in oil, the fixing groove 112 is a counter bore, and the fixing groove 112 is sleeved on the periphery of one end of the insulating tube 1100 in oil and is fixed by cementing. Meanwhile, the cementing end cover 110 is provided with a first through hole 111 along the axial direction, the first through hole 111 and the fixing groove 112 are coaxially arranged, the diameter of the first through hole 111 is smaller than the diameter of the fixing groove 112 and slightly larger than the outer diameter of the connecting portion 121, so that a first step surface is formed at the joint of the first through hole 111 and the fixing groove 112, the first step surface is abutted against the end surface of the insulating tube 1100 in oil, and the connecting portion 121 can be accommodated in the first through hole 111.

Further, one end, far away from insulating tube 1100 in the oil, of cementing end cover 110 sets up mounting groove 113, and mounting groove 113 and fixed slot 112 are coaxial to be set up, and the diameter of mounting groove 113 is greater than the diameter of first through-hole 111 and slightly is greater than the diameter of installation department 122, so, the junction of mounting groove 113 and first through-hole 111 forms the second step face, along a plurality of screw holes 114 of circumference equipartition on the second step face, and installation department 122 can hold in mounting groove 113.

In this embodiment, the mounting groove 113 is matched with the mounting portion 122 in shape, so that the mounting and dismounting are facilitated, and the mounting end cover 120 is fixedly connected with the cementing end cover 110 through a fastener, so that the mounting end cover is not easy to fall off in the operation process, and the equipment damage is avoided.

In other embodiments, the glue end cover and the mounting end cover can be connected by glue or by a buckle, as long as the fixed connection between the glue end cover and the mounting end cover can be ensured.

In this embodiment, first lock nut 130, installation end cover 120 and second lock nut 140 cup joint in proper order behind the periphery of central conducting rod 1200, whole and mucilage binding end cover 110 butt, first lock nut 130 promptly, first through-hole 111 is arranged in to connecting portion 121 of installation end cover 120, installation portion 122 is arranged in mounting groove 113, and installation portion 122 is close to terminal surface and the second step face butt of insulating tube 1100 in the oil, be equipped with the mounting hole 123 that matches with screw hole 114 on the installation portion 122, screw hole 114 corresponds to the installation of fastening through the fastener after matching with mounting hole 123, guarantee that installation end cover 120 is fixed with mucilage binding end cover 110, thereby guarantee the fixed of central conducting rod 1200.

In this embodiment, a first seal groove is provided at a position where the cementing end cover 110 contacts with the end surface of the insulating pipe 1100 in oil, and the first seal ring 150 is placed in the first seal groove. The first sealing ring 150 is provided to prevent the leakage of the insulating oil along the contact surface between the oil insulating tube 1100 and the end cap 110.

In this embodiment, the mounting end cap 120 is provided with a second sealing groove at a position contacting the central conductive rod 1200 and the first clamping nut 130, and the second sealing ring 160 is placed in the second sealing groove; the mounting end cap 120 provides a third seal groove in which the third seal ring 170 is placed at a position in contact with the center conductor bar 1200 and the second clamping nut 140. The second sealing ring 160 is disposed to prevent the insulating oil from leaking along the central conductive rod 1200, and the third sealing ring 170 serves as a double seal to enhance the sealing effect.

In this embodiment, the fourth sealing groove is disposed at the position of the mounting portion 122 close to the connecting portion 121 and contacting with the glued end cover 110 to place the fourth sealing ring 180, so as to prevent the insulating oil from leaking from the connecting portion between the glued end cover 110 and the mounting end cover 120. In the radial direction of installation portion 122, mounting hole 123 sets up in the periphery of fourth seal groove, ensures that fourth sealing washer 180 can realize its sealed function, prevents that insulating oil from leaking from mounting hole 123 department, and mounting hole 123 need keep away from fourth sealing washer 180 certain distance, destroys fourth sealing washer 180 when preventing the installation fastener, causes sealed inefficacy.

In this embodiment, the second and

third seal rings

160 and 170 have a trapezoidal cross section, and the first and

fourth seal rings

150 and 180 have a rectangular cross section.

In other embodiments, the shape of the sealing ring is not limited, and various shapes such as a rectangular sealing ring, an O-ring, a special-shaped sealing ring, etc. may be used as long as the sealing between the mounting end cap and the central conductive rod is achieved.

As shown in fig. 3, in the present embodiment, three first tightening grooves 131 are provided on the outer circumference of the first tightening nut 130 for installation and tightening, and the three first tightening grooves 131 are evenly distributed in the circumferential direction. The first tightening groove 131 is formed in a square column shape to penetrate in the axial direction of the first tightening nut 130. The arrangement of the first tightening recess 131 provides a space for a tool for rotating the nut, facilitating the assembly and the reverse rotation of the first tightening nut 130.

In other embodiments, the number and shape of the first abutting groove are not limited, and the first abutting groove may be cylindrical or prismatic. In addition, the first tight supporting groove may not be through.

As shown in fig. 4, in the present embodiment, the second clamping nut 140 is provided with four second clamping grooves 141 for installation and clamping away from the end surface of the insulating tube in oil 1100, and the four second clamping grooves 141 are evenly distributed in the circumferential direction. The second tightening groove 141 is cylindrical and does not penetrate, leakage risk of insulating oil is avoided, a space is provided for a tool for rotating the nut due to the arrangement of the second tightening groove 141, and assembly of the second tightening nut 140 is facilitated.

In other embodiments, the number and shape of the second tightening groove are not limited, and the second tightening groove may be in the shape of a square column or a prism.

The terminal assembly 100 of this embodiment includes the first lock nut 130, the installation end cover 120, the second lock nut 140 that set gradually at the end of the central conducting rod 1200, can prevent the rotation between the central conducting rod 1200 and the installation end cover 120 after locking through the screw thread between the central conducting rod 1200 and the three, and can make the experimental tap on the electric capacity core correspond with the mounting hole position through rotatory installation end cover 120, can not take place the dislocation, in addition, because do not set up the pin, can not lead to the damage of second sealing washer 160 and third sealing washer 170. .

Example two:

the present embodiment provides a method of installing a tip assembly 100, referring to fig. 1 and 2, comprising the steps of:

step a: cementing and fixing the insulating tube 1100 in oil with the cementing end cover 110;

the method comprises the following specific steps: a first seal groove is formed in the contact position of the cementing end cover 110 and the end part of the insulating tube 1100 in oil, and a first seal ring 150 is placed to ensure the sealing connection between the cementing end cover 110 and the insulating tube 1100 in oil;

one end of the cementing end cover 110, which is provided with the fixing groove 112, is connected with the tail of the insulating tube 1100 in oil, an adhesive is injected through the glue injection hole, so that the fixing groove 112 is filled with the adhesive, and the adhesive is cured, so that the cementing end cover 110 is fixed to the tail of the insulating tube 1100 in oil.

And injecting a sealant into the outer surface of the cementing end cover 110, which is in contact with the oil insulating tube 1100, and curing the sealant, so that water vapor invasion is prevented, the sealing effect is enhanced, and the service life is prolonged.

Further, the adhesive is flange glue, and the sealant is room-temperature vulcanized silicone rubber.

In other embodiments, the adhesive and the sealant can be other types of adhesives, and the adhesive end cover and the oil-in-oil insulating tube can be fixedly connected.

Step b: extending the central conductive rod 1200 out of one end of the insulating tube in oil 1100, and rotating the first clamping nut 130 to the end of the central conductive rod 1200 through the first clamping groove 131;

specifically, the first clamping nut 130 is rotated to the end of the central conductive rod 1200 by means of the principle of leverage with one end of an installation tool, such as a screwdriver, abutting against the groove of the first clamping groove 131.

Step c: mounting the mounting end cap 120 to the end of the central conductive rod 1200 adjacent to the first jam nut 130;

the method comprises the following specific steps: the second seal ring 160 is first placed in the second seal groove, the third seal ring 170 is placed in the third seal groove, and the mounting end cap 120 is rotated to a position on the central conductive rod 1200 close to the first clamping nut 130 by the screw thread inside the connecting portion 121. The setting of screw thread makes the installation more convenient to can make things convenient for subsequent rotation so that the position of adjusting experimental tap, prevent dislocation between experimental tap and the mounting hole. The second sealing ring 160 is disposed to prevent the insulating oil from leaking along the central conductive rod 1200, and the third sealing ring 170 serves as a double seal to enhance the sealing effect.

Step d: reversely rotating the first clamping nut 130 through the first clamping groove 131 to clamp the first clamping nut 130 and the mounting cap 120;

the first jam nut 130 is reversely rotated by means of the lever principle again using one end of an installation tool such as a screwdriver against the groove of the first jam groove 131, so that the first jam nut 130 is jammed with the installation cap 120.

Step e: the central conducting rod 1200 connected with the first clamping nut 130 and the mounting end cover 120 is fixedly mounted with the cementing end cover 110 through a fastener;

the method comprises the following specific steps: a fourth sealing ring 180 is arranged in a fourth sealing groove on the mounting part 122 close to one side of the connecting part 121 and in contact with the cementing end cover 110, so that the sealing connection between the mounting end cover 120 and the cementing end cover 110 is ensured, and the insulating oil is prevented from leaking from the connecting part between the cementing end cover 110 and the mounting end cover 120; then, the central conductive rod 1200 connected with the first clamping nut 130 and the mounting end cap 120 is pushed into one end of the insulating tube 1100 in oil, so that the mounting portion 122 is tightly connected with the mounting groove 113; finally, the fastener passes through the mounting hole 123 on the mounting portion 122 and is inserted into the screw hole 114 on the cementing end cover 110, so as to realize the fixed connection between the mounting end cover 120 and the cementing end cover 110.

Step f: the second clamping nut 140 is rotated from the groove 124 to the end of the center conductor bar 1200 by the second clamping groove 141 to be clamped with the mounting cap 120.

The second jam nut 140 rotates in the same manner as the first jam nut 130 and is not described in detail.

The method for mounting the terminal assembly 100 provided by the embodiment has a simple process and is easy to operate, and the test tap on the capacitor core can correspond to the mounting hole by rotating the mounting end cover 120, so that the dislocation is avoided.

Example three:

as shown in fig. 5, the present embodiment provides a transformer bushing 1000, the transformer bushing 1000 includes the above-mentioned terminal assembly 100, and the center conductive rod 1200 of the transformer bushing 1000 is tightly connected to the mounting end cap 120 through the first clamping nut 130 and the second clamping nut 140, and will not shift or rotate under the state of force or vibration, and has a stable structure and excellent performance.

In other embodiments, the transformer bushing includes any of the above-described locally varying end assemblies, which are not described in detail herein.

While the specification and features of the present application have been described above, it will be understood that various changes and modifications in the above-described constructions and materials, including combinations of features disclosed herein either individually or in any combination, will be apparent to those skilled in the art upon studying the disclosure. Such variations and/or combinations are within the skill of the art to which the invention pertains and are within the scope of the following claims.

Claims

1. A terminal assembly for a transformer bushing, the transformer bushing comprising a tube of insulation in oil and a capacitive core disposed through the tube of insulation in oil, the capacitive core comprising a central conductive rod, wherein: the tail end assembly comprises a cementing end cover, a mounting end cover, a first clamping nut and a second clamping nut;

one end of the cementing end cover is provided with a fixing groove for fixing the insulating tube in the oil, the cementing end cover is also provided with a first through hole for accommodating the mounting end cover, and the end of the cementing end cover far away from the insulating tube in the oil is matched with the end of the mounting end cover close to the insulating tube in the oil in shape and is in sealing connection with the end;

the installation end cover is provided with a second through hole coaxial with the first through hole for the central conducting rod to pass through, and the installation end cover is provided with a second clamping nut which is sequentially fixed and sleeved on the end part of the central conducting rod and clamped and tightened by the second clamping nut.

2. The tip assembly of claim 1, wherein: the installation end cover includes connecting portion and installation department, connecting portion with the installation department makes for the hollow cylinder of coaxial setting the whole T style of calligraphy setting that is of installation end cover, just connecting portion are used for cup jointing central conducting rod, the installation department be used for with cementing end cover fixed connection.

3. The tip assembly of claim 2, wherein: the one end that the mucilage binding end cover kept away from insulating tube in the oil sets up the mounting groove, the mounting groove with the installation department matches and passes through fastener fixed connection.

4. The tip assembly of claim 1, wherein: one end, far away from the oil insulation pipe, of the mounting end cover is provided with a groove, and the second clamping nut is placed in the groove.

5. The tip assembly of claim 1, wherein: the periphery of the first clamping nut is provided with at least one first clamping groove for installation and clamping.

6. The tip assembly of claim 1, wherein: and the end surface of the second clamping nut, which is far away from the oil-in-oil insulating pipe, is provided with at least one second clamping groove for mounting and clamping.

7. The tip assembly of claim 1, wherein: and a first sealing ring is arranged at the joint of the end face of the insulating tube in the oil and the cementing end cover.

8. The tip assembly of claim 1, wherein: the first clamping nut and the second sealing ring are arranged between the mounting end covers, and the second clamping nut and the third sealing ring are arranged between the mounting end covers.

9. A method of installing the terminal assembly of claim 1, the central conductive rod being located inside the insulating tube in oil, characterized by: comprises the following steps:

step a: cementing and fixing the insulating tube in the oil and the cementing end cover;

step b: extending the central conducting rod out of one end of the insulating tube in oil, and rotating the first clamping nut to the end part of the central conducting rod;

step c: mounting the mounting end cap to the end of the central conductor bar proximate the first draw-down nut;

step d: reversely rotating the first clamping nut to clamp the first clamping nut and the mounting end cover;

step e: the central conducting rod connected with the first clamping nut and the mounting end cover is fixedly mounted with the cementing end cover through a fastener;

step f: and rotating the second clamping nut to the end part of the central conducting rod to clamp the central conducting rod with the mounting end cover.

10. A transformer bushing, characterized by: the transformer bushing employs the tip assembly of any of claims 1 to 8.