Built-in current transformer

Abstract

The invention discloses a built-in current transformer, and belongs to the technical field of current transformers, the built-in current transformer comprises an upper support insulator, a shell, a lower support insulator, a support cylinder, a plurality of coils, a matching tooth assembly, a rack, a slip sheet and an elastic structure, the shell comprises a radial contraction section, a vertical gap between the inner wall of the radial contraction section and the upper port of the supporting cylinder is a shielding gap; the multiple coils sequentially sleeve the outer side of the supporting cylinder in the axial direction, the matching tooth assembly comprises multiple first triangular teeth which are fixedly connected with the outer wall of the supporting cylinder, the racks are parallel to the axis of the supporting cylinder and provided with multiple second triangular teeth, and the upper ends of the racks abut against the lower surface of the sliding piece. The elastic force of the elastic structure is used for forcing the rack to move downwards so that the complete attaching state of the second triangular tooth inclined face and the first triangular tooth inclined face can be changed into the partial attaching state of the second triangular tooth inclined face and the first triangular tooth inclined face. The installation stability and convenience of the coil can be improved.

Description

Technical Field

[0001] The present application belongs to the technical field of current transformers and relates to a built-in current transformer. Background Art

[0002] As one of the important components of GIS, the current transformer is an important electrical equipment in the power system. Its main function is to convert the large current on the primary side of the system into a small current according to the specified ratio, isolate the large current in the primary circuit, and provide current for various instruments and relay protection in the secondary system.

[0003] The existing built-in current transformer forms an airtight cavity inside the shell, an inner support tube is arranged in the airtight cavity, and a coil is mounted outside the inner support tube. The existing structure refers to the Chinese patent announcement number CN213546101U, and the coil is fixed to the outside of the inner support tube by epoxy resin pouring. Although this method can improve the installation stability of the coil, it is necessary to use tooling to apply a large axial pressure to the coil to ensure that the gap between the coils is extremely small to reduce the overflow of the high-pressure poured epoxy resin. In this way, the coil is easily crushed, especially the coil with a core, and this method is relatively cumbersome.

[0004] Secondly, the background technology of the Chinese patent with announcement number CN213546101U also provides a fixing method, that is, using tightening bolts to support the pressure plate, the pressure plate applies axial pressure to each coil to complete the fixation. This method is more convenient than epoxy resin casting, and the axial pressure applied is smaller, and the damage to the coil is smaller. However, this fixing method only limits the axial position of the coil. During transportation or vibration, the coil may move circumferentially and radially, and the bolts may also be loose, that is, the stability of the coil is poor. Summary of the invention

[0005] In order to solve the problem that it is difficult to strike a balance between the convenience and stability of coil fixation, a built-in current transformer is provided.

[0006] The present application provides a built-in current transformer, which is specifically implemented by the following technical solutions: A built-in current transformer, comprising an upper support insulator, a shell, a lower support insulator, a support tube, a plurality of coils, a matching tooth assembly, a rack, a slide and an elastic structure, wherein the support tube is coaxially arranged with the shell, a flange is integrally formed on the outer wall of the lower end of the support tube, an annular resin pad is arranged on the upper surface of the flange, the flange is fixedly connected to the lower end of the shell by a first bolt, the lower end of the shell has a threaded hole matching with the first bolt, the screw head of the first bolt presses against the lower surface of the flange; the shell comprises a radial contraction section, and the vertical gap between the inner wall of the radial contraction section and the upper port of the support tube is a shielding gap; a plurality of coils are sequentially sleeved on the outer side of the support tube along the axial direction, the lowest coil presses against the resin pad, and the matching The tooth assembly includes a plurality of first triangular teeth evenly arranged along the axial direction of the support tube, the first triangular teeth are fixedly connected to the outer wall of the support tube, the rack is parallel to the axis of the support tube, the surface of the rack has a first rubber coating, the rack has a plurality of second triangular teeth, the slide is axially slidably matched with the support tube, the upper end of each rack abuts against the lower surface of the slide, the elastic structure is installed on the inner wall of the radial contraction section, the elastic force of the elastic structure is used to force the rack to move downward to change the state where the second triangular tooth bevel and the first triangular tooth bevel are completely in contact with each other to a state where the second triangular tooth bevel and the first triangular tooth bevel are partially in contact with each other, and when the second triangular tooth bevel and the first triangular tooth bevel are partially in contact with each other, the side wall of the rack abuts against the inner circumference of the coil.

[0007] Through the above technical scheme, during installation, the rack is installed on the outside of the support tube. At this time, the second triangular tooth bevel is completely fitted with the first triangular tooth bevel, the radial distance between the rack and the support tube is the smallest, and the outer diameter of the virtual circle surrounded by each rack is the smallest. The rack is not easy to interfere with the coil, which makes it easy to sleeve the coil on the outside of the support tube. At this time, there is a radial gap between the rack and the inner diameter of the coil. Then the slide is sleeved on the upper end of the support tube to ensure that the lower surface of the slide abuts against the upper end of the rack. Then the support tube is installed in the shell, and the first bolt is tightened to drive the support tube and the coil to move upward relative to the shell. The slide touches the elastic structure during the upward movement of the support tube, and the elastic structure accumulates elastic potential energy. The elastic force of the elastic structure is applied downward to the slide, and the slide forces the rack to move downward to move the first The state where the second triangular tooth bevel is completely in contact with the first triangular tooth bevel changes to the state where the second triangular tooth bevel is partially in contact with the first triangular tooth bevel. At the same time, under the guidance of the first triangular tooth bevel, the rack moves radially outward along the support tube. The outer diameter of the virtual circle formed by each rack is the largest. The side wall of the rack abuts against the inner circumference of the coil to clamp each coil, thereby limiting the circumferential and radial movement of the coil. In addition, since the surface of the rack has a first rubber coating, the friction coefficient of the first rubber coating is large, and the coil is axially limited by friction force, thereby greatly improving the installation stability of the coil. No additional tooling is required. That is, in the process of installing the support tube, when the support tube moves relative to the shell, the energy stored in the elastic structure is utilized to complete the fixation of the coil, which is more convenient.

[0008] Moreover, during use or transportation, the elastic force of the elastic structure is always applied to the rack. When the coil vibrates radially, the rack has a vertical displacement tendency. The elastic structure will buffer the displacement tendency of the rack, and the vertical displacement of the rack will rub against the coil. The kinetic energy of the vibration is converted into frictional heat energy, thereby achieving a shock-absorbing effect.

[0009] Optionally, the inclined surface of the first triangular tooth has a second rubber coating, and the inclined surface of the second triangular tooth has the first rubber coating.

[0010] Through the above technical solution, when the coil vibrates radially and the second triangular tooth of the rack and the first triangular tooth of the support tube are relatively displaced, since the first rubber coating and the second rubber coating have a certain friction coefficient, the relative displacement friction between the two generates heat, and the kinetic energy of the vibration is converted into frictional heat energy, thereby achieving a shock absorbing effect.

[0011] Optionally, a strip groove is axially penetrated through the outer circumferential surface of the support tube, and the bottom of the strip groove is integrally formed with the first triangular tooth; the two opposite groove walls of the strip groove have a third rubber coating, and the first rubber coating surface of the rack is fitted with the third rubber coating surface of the strip groove.

[0012] Through the above technical solution, by setting the cooperation between the strip groove and the rack, it is possible to limit the rack along the circumference of the support tube, and the first rubber coating surface of the rack is in contact with the third rubber coating surface of the strip groove. Since the first rubber coating and the third rubber coating have a certain friction coefficient, there is a matching damping between the first rubber coating and the third rubber coating, so that after the rack is assembled to the strip groove, the rack is not easy to fall out, so that the rack can be deeply hidden in the strip groove, and the outer diameter of the virtual circle enclosed by each rack is small, so as to facilitate the insertion of the coil.

[0013] Optionally, the mating tooth assembly also includes a resin sleeve, the outer wall of the support tube is provided with a spline, and the inner wall of the resin sleeve is provided with a keyway that cooperates with the spline; a strip groove is axially penetrated through the outer wall of the resin sleeve, and the bottom of the strip groove is integrally formed with the first triangular tooth; the two opposite groove walls of the strip groove have a third rubber coating, and the first rubber coating surface of the rack is fitted with the third rubber coating surface of the strip groove.

[0014] Through the above technical solution, the resin sleeve is integrally injection molded, and its molding and manufacturing is relatively simple. The dimensional accuracy of the first triangular tooth is high, which can improve the displacement accuracy of the rack, thereby improving the fixing accuracy of the coil.

[0015] Optionally, the elastic structure includes a connecting ring and a plurality of first spring sheets, the connecting ring being fixed to the inner wall of the radial contraction section by a second bolt, the first spring sheets being evenly arranged along the circumference of the support tube, one end of the first spring sheet being integrally connected to the connecting ring, the other end of the first spring sheet being inclined downward and extending toward the axial direction of the support tube, and the lower end of the first spring sheet being elastically pressed against the upper surface of the slide.

[0016] Through the above technical solution, a connecting ring is provided, which is installed on the inner wall of the radial contraction section by a second bolt, so as to realize the fixation between multiple first spring pieces and the shell, which is more convenient. In addition, multiple first spring pieces are evenly distributed, and elastic force can be applied to the sliding piece more evenly, thereby improving the displacement stability of each rack.

[0017] Optionally, the elastic structure includes a connecting ring and a plurality of second elastic sheets, the connecting ring and the inner wall of the radial contraction section are fixed by a second bolt, and the second elastic sheets are evenly arranged along the circumference of the support tube; the second elastic sheets include a first inclined section, a first U-shaped easy-to-bend section, a second inclined section, a first return section, a third inclined section, a second U-shaped easy-to-bend section, a fourth inclined section, a second return section, a fifth inclined section and a third return section connected in sequence along a direction away from the connecting ring, wherein the first inclined section and the second inclined section are both inclined downward, the third inclined section and the fourth inclined section are both inclined upward, and the fifth inclined section is inclined downward, and a protrusion is fixed to the inner wall of the radial contraction section, and the protrusion abuts against the side of the fourth inclined section; when the first bolt is tightened to drive the support tube During the upward movement of the cylinder and the coil relative to the shell, the upper surface of the slide first abuts against the outer arc surface of the third fold segment, and the elastic force of the fifth inclined segment passes through the third fold segment to force the slide to move downward, so as to change the state in which the second triangular tooth slope and the first triangular tooth slope are completely in contact with each other to a state in which the second triangular tooth slope and the first triangular tooth slope are partially in contact with each other. At this time, the surface of the coil again abuts against the outer arc surface of the first fold segment, the first U-shaped bendable section is elastically compressed, and the second inclined section and the third inclined section are deflected upward. The elastic force of the first U-shaped bendable section passes through the second inclined section and the first fold segment to force each coil to be axially compressed, and the upward deflection of the third inclined section will drive the fourth inclined section and the fifth inclined section to deflect downward with the protrusion as the fulcrum.

[0018] Through the above technical scheme, when tightening the first bolt, the screw head of the first bolt abuts against the lower surface of the flange to drive the flange to move upward relative to the shell, thereby driving the support tube and the coil to move upward relative to the shell. During this process, the upper surface of the slide first abuts against the outer arc surface of the third fold segment (at this time, the coil has not yet contacted the first fold segment), and the elastic force of the fifth inclined segment forces the slide to move downward through the third fold segment to change the state in which the second triangular tooth bevel and the first triangular tooth bevel are completely in contact with each other to a state in which the second triangular tooth bevel and the first triangular tooth bevel are partially in contact with each other. During this state switching process, under the guidance of the first triangular tooth bevel, the rack moves radially outward along the support tube, thereby limiting the circumferential and radial movements of the coil; continue to tighten the first bolt to drive the support tube and the coil to move upward, and the fifth inclined segment continues to accumulate elastic potential energy to force the rack to continue to move radially outward. The outer diameter of the virtual circle enclosed by each rack is the largest, and the side wall of the rack abuts against the inner circumference of the coil to clamp each coil, and the clamping force becomes larger and larger, and the surface of the coil begins to abut against The outer arc surface of the first fold segment, the first U-shaped easy-bend segment is elastically compressed, and the second inclined segment and the third inclined segment are deflected upward. The elastic force of the first U-shaped easy-bend segment forces the coils to be axially compressed through the second inclined segment and the first fold segment to reduce the axial gap between the coils, thereby reducing the vibration and collision of the coils caused by the axial gap between the coils. At the same time, the upward deflection of the third inclined segment will drive the fourth inclined segment and the fifth inclined segment to deflect downward with the protrusion as the fulcrum, and the downwardly deflected fifth inclined segment further applies downward pressure to the slide and the rack through the third fold segment, further increasing the clamping force of the rack on the coil, thereby improving the installation stability of the coil. It can be understood that within the limited axial displacement space of the support tube and the coil, the elastic deformation amount triggered by the second spring sheet is limited, and by increasing the linkage of the second inclined segment, the fourth inclined segment, the fifth inclined segment and the protrusion, the clamping force of the fifth inclined segment on the rack is further increased, thereby greatly improving the installation stability of the coil under limited conditions.

[0019] Optionally, the elastic structure includes a connecting ring, a plurality of second spring sheets and a force transmission rod, the connecting ring is fixed to the inner wall of the radial contraction section by a second bolt, and the second spring sheets are evenly arranged along the circumference of the support tube; the second spring sheets include a first inclined section, a first U-shaped easy-to-bend section, a second inclined section, a first return section, a third inclined section, a second U-shaped easy-to-bend section, a fourth inclined section, a second return section, a fifth inclined section and a third return section connected in sequence along a direction away from the connecting ring, wherein the first inclined section and the second inclined section are both inclined downward, the third inclined section and the fourth inclined section are both inclined upward, and the fifth inclined section is inclined toward The cam is arranged at the bottom, the inner wall of the radial contraction section is fixed with a convex block, and the convex block abuts against the side of the fourth inclined section; the two force transmission rods are respectively located on both sides of the width direction of the second inclined section, one end of the force transmission rod is welded and fixed to the middle part of the side of the second inclined section, and the other end of the force transmission rod is fixed with a plurality of one-way teeth arranged at equal intervals along its own length direction, the one-way teeth are right-angled triangles, and the side of the fifth inclined section is stuck in the one-way teeth; a rubber ring is provided at the matching gap between the lower end of the shell and the flange; when the first bolt is tightened to drive the support tube and the coil to move upward relative to the shell, the surface of the coil The first U-shaped bendable section first abuts against the outer arc surface of the first return section, the first U-shaped bendable section is elastically compressed, the second inclined section and the third inclined section are deflected upward, and the second inclined section deflected upward drives the force transmission rod to move relative to the fifth inclined section, and each one-way tooth elastically avoids the fifth inclined section in turn, and the elastic force of the first U-shaped bendable section passes through the second inclined section and the first return section to force each coil to be axially compressed; continue to tighten the first bolt to make the support tube continue to move upward, and the upper surface of the sliding plate abuts against the outer arc surface of the third return section again, and the elastic force of the fifth inclined section passes through the third return section to force the sliding plate to move downward, so as to align the inclined surface of the second triangular tooth with the inclined surface of the first triangular tooth The tooth bevel is completely in contact with the state in which the second triangular tooth bevel is partially in contact with the first triangular tooth bevel. At this time, the side wall of the rack abuts against the inner circumference of the coil and the rubber ring is in a completely compressed state. Then the first bolt is loosened, and the support tube and the coil move down until the rubber ring is in an incompletely compressed state. The first U-shaped bendable section recovers part of its elastic deformation, and the second inclined section deflects downward. Since the side edge of the second inclined section is stuck in the thick end of the one-way tooth, the second inclined section will drive the fifth inclined section to deflect downward together. There is a gap between the outer arc surface of the first bend section and the coil, and the third bend section remains in a state of elastically abutting against the sliding sheet.

[0020] Through the above technical scheme, when tightening the first bolt, the screw head of the first bolt abuts against the lower surface of the flange to drive the flange to move upward relative to the shell, thereby driving the support tube and the coil to move upward relative to the shell. During this process, the surface of the coil first abuts against the outer arc surface of the first return segment (the upper surface of the slide has not yet contacted the third return segment), the first U-shaped easy-to-bend segment is elastically compressed, the second inclined segment and the third inclined segment are deflected upward, and the second inclined segment deflected upward drives the force transmission rod to move relative to the fifth inclined segment, and each unidirectional tooth elastically avoids the fifth inclined segment in turn, and the elastic force of the first U-shaped easy-to-bend segment passes through the second inclined segment and the first return segment to force each coil to be axially compressed to reduce the axial gap between the coils, thereby reducing the vibration and collision of the coils caused by the axial gap of the coils; continue to tighten the first bolt to make the support tube continue to move upward until the rubber ring is in a fully compressed state. During this process, the upper surface of the slide again abuts against the outer arc surface of the third return segment, and the elastic force of the fifth inclined segment passes through the third return segment to force the slide to move downward, so as to align the second triangular tooth bevel with the first The fully fitted state of the triangular tooth bevel is changed to a partially fitted state of the second triangular tooth bevel and the first triangular tooth bevel. During the state switching process, under the guidance of the first triangular tooth bevel, the rack moves radially outward along the support tube, thereby limiting the circumferential and radial movements of the coil; then the first bolt is loosened, and the support tube and the coil move down until the rubber ring is in an incompletely compressed state (the compression degree of the rubber ring is 30% to 70% of the fully compressed state). After the first fold segment loses the contact with the coil, the first fold segment has a movable space, so that the first fold segment can move freely. A U-shaped easy-to-bend section recovers part of its elastic deformation, and the second inclined section deflects downward. Since the side of the second inclined section is stuck in the thick end of the one-way tooth, the second inclined section will drive the fifth inclined section to deflect downward together, and the downwardly deflected fifth inclined section further applies downward pressure to the slide and the rack through the third folded section, further improving the clamping force of the rack on the coil, thereby improving the installation stability of the coil. Finally, there is a gap between the outer arc surface of the first folded section and the coil, that is, the coil is not subjected to axial pressure, thereby reducing the occurrence of axial compression of the coil.

[0021] To summarize the installation process, the second inclined section first applies axial pressure to the coil to compress the gap between the coils, and the fifth inclined section then abuts the slide to complete the outward expansion of the rack, and the rack radially clamps the coil. Secondly, loosen the first bolt to move the support tube and the coil downward to relieve the axial pressure on the coil and reduce the pressure damage to the coil. At the same time, the force transmission rod is used to make the fifth inclined section and the second inclined section form a whole, so that the elastic force of the fifth inclined section and the elastic force of the first U-shaped bendable section are superimposed on the rack to further improve the clamping effect. It can be understood that, within the limited axial displacement space of the support tube and the coil, the amount of elastic deformation triggered by the second spring sheet is limited, and by utilizing the different upward and downward movement steps of the support tube and the coil, the compression of the axial gap between the coils is first satisfied, and then the clamping of the coil by the rack is satisfied, and finally the linkage of the force transmission rod is utilized to superimpose the elastic force of the fifth inclined section and the elastic force of the first U-shaped bendable section, so that the clamping force of the rack is further increased, thereby greatly improving the installation stability of the coil under limited conditions, reducing the axial vibration and collision between the coils, and reducing the compression caused by excessive axial pressure on the coil.

[0022] Optionally, a sliding groove is provided at the upper end of the rack, and a sliding bar is connected to the sliding groove for radial sliding along the supporting tube, the sliding bar is located between the coil and the sliding piece, and an elastic bent claw is integrally formed at one end of the sliding bar, and the sliding bar is provided with a plurality of inclined spring pieces evenly arranged along its own length direction, and the outer wall of the supporting tube is provided with a matching groove for radially engaging the elastic bent claw, and a plurality of guide teeth evenly arranged along its own radial direction are fixed to the lower surface of the sliding piece, and the inclined surface of the guide teeth fits with the inclined surface of the inclined spring piece.

[0023] Through the above technical scheme, during the downward movement of the slide under the elastic force of the fifth inclined section, since the inclined surface of the guide tooth of the slide fits with the inclined surface of the inclined spring sheet, the downward movement trend of the slide will be converted into a trend forcing the slide to move radially inward along the support tube, so that the elastic bent claws of the slide radially fit into the matching groove to complete the radial limitation of the slide. The slide is located between the coil and the slide, and the slide plays a filling role to axially limit the coil. The inclined spring sheet is elastic, and the elastic potential energy accumulated by the inclined spring sheet will be applied to the coil, so that the axial limiting force of the coil is relatively elastic and moderate, so as to reduce the occurrence of the coil being crushed due to excessive axial limiting force.

[0024] Optionally, the shielding gap is 3-7 mm.

[0025] Optionally, the shell includes an upper shell, the radial contraction section and a lower shell from top to bottom, the inner diameter of the upper shell is smaller than the inner diameter of the lower shell, the upper shell is fixed to the upper support insulator and a first O-ring is provided at the mating position, the lower shell is fixedly connected to the flange plate by the first bolt and a second O-ring is provided at the mating position, and the flange plate is fixed to the lower support insulator and a third O-ring is provided at the mating position.

[0026] The above technical solution can improve the sealing performance of the shell and reduce the leakage of insulating gas.

[0027] The beneficial effects of this application are: 1. By setting a rack, a first triangular tooth and an elastic structure, the first triangular tooth and the second triangular tooth are used to cooperate to guide the rack to move radially outward, and the side wall of the rack abuts against the inner circumference of the coil to clamp each coil, thereby limiting the circumferential and radial movements of the coil. In addition, since the surface of the rack has a first rubber coating, the friction coefficient of the first rubber coating is relatively large, and the coil is axially limited by friction, thereby greatly improving the installation stability of the coil; and no additional tooling is required, that is, during the installation of the support cylinder, when the support cylinder moves relative to the shell, the energy stored in the elastic structure is used to complete the fixation of the coil, which is more convenient; and when the coil vibrates radially, the elastic structure will buffer the displacement trend of the rack, and the vertical displacement of the rack will rub against the coil, and the kinetic energy of the vibration will be converted into frictional heat energy, thereby achieving a shock absorbing effect; 2. The second inclined section first applies axial pressure to the coil to compress the gap between the coils, and the fifth inclined section then abuts the slide to complete the outward expansion of the rack, and the rack radially clamps the coil. Secondly, loosen the first bolt to move the support tube and the coil downward to release the axial pressure on the coil and reduce the pressure damage to the coil. At the same time, the force transmission rod is used to make the fifth inclined section and the second inclined section form a whole, so that the elastic force of the fifth inclined section and the elastic force of the first U-shaped bendable section are superimposed on the rack, further improving the clamping effect. It can be understood that, within the limited axial displacement space of the support tube and the coil, the amount of elastic deformation triggered by the second spring sheet is limited, and by utilizing the different upward and downward movement steps of the support tube and the coil, the compression of the axial gap between the coils is first satisfied, and then the clamping of the coil by the rack is satisfied, and finally the linkage of the force transmission rod is utilized to superimpose the elastic force of the fifth inclined section and the elastic force of the first U-shaped bendable section, so that the clamping force of the rack is further increased, thereby greatly improving the installation stability of the coil under limited conditions, reducing the axial vibration and collision between the coils, and reducing the compression caused by excessive axial pressure on the coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a cross-sectional view of the overall structure of Example 1.

[0029] Figure 2 yes Figure 1 Cross-sectional view along the AA direction.

[0030] Figure 3 yes Figure 1 A partial enlarged view of point B in the middle.

[0031] Figure 4 Schematic diagram of the elastic structure of Example 1.

[0032] Figure 5 It is a cross-sectional view of the support tube of Example 2.

[0033] Figure 6 It is a cross-sectional view of the overall structure of Example 3.

[0034] Figure 7 yes Figure 6 A partial enlarged view of point C in the middle.

[0035] Figure 8 Schematic diagram of the second spring piece of Example 3.

[0036] Fig. 9 It is a schematic diagram of Example 3 for showing the state in which the support tube moves up to the initial contact state between the slide and the third folded section.

[0037] Fig.10 Schematic diagram of the second spring piece of Example 4.

[0038] Fig.11 It is a partial cross-sectional view of Example 4 for demonstrating the fitting relationship between the lower shell and the flange.

[0039] Fig.12 It is a schematic diagram of Example 4 for illustrating the state change of the second spring piece during the upward movement of the support tube and after the support tube retracts.

[0040] Fig.13 It is a schematic diagram of Example 4 for demonstrating the change in the matching state of the guide teeth and the inclined spring piece during the upward movement of the support tube.

[0041] Description of the reference numerals: 1. mating tooth assembly; 2. rack; 3. elastic structure; 10. housing; 101. upper housing; 1011. first O-ring; 1012. second O-ring; 1013. third O-ring; 102. radial contraction section; 1021. convex block; 103. lower housing; 104. upper support insulator; 105. lower support insulator; 106. coil; 107. support cylinder; 1071. flange; 1072. resin pad; 1073. strip groove; 1074. spline; 108. first bolt; 1081. threaded hole; 1082. rubber ring; 11. first triangular tooth; 12. resin sleeve; 13. Keyway; 15, matching groove; 20, sliding groove; 21, second triangular tooth; 22, sliding piece; 221, guide tooth; 23, sliding ring; 30, second bolt; 31, connecting ring; 32, first spring piece; 33, second spring piece; 330, third folding section; 331, first inclined section; 332, second inclined section; 333, third inclined section; 334, fourth inclined section; 335, fifth inclined section; 336, first U-shaped easy-bending section; 337, first folding section; 338, second U-shaped easy-bending section; 339, second folding section; 35, force transmission rod; 36, one-way tooth; 37, sliding bar; 371, elastic bending claw; 372, inclined spring piece. DETAILED DESCRIPTION

[0042] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the attached Figure 1-Figure 13 Shown in.

[0043] In the description of this specification, the description with reference to the terms "certain embodiments", "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0044] Example 1 Embodiment 1 discloses a built-in current transformer, such as Figure 1 As shown, the built-in current transformer includes an upper support insulator 104 , a housing 10 , a lower support insulator 105 , a support cylinder 107 , a plurality of coils 106 , a mating tooth assembly 1 , a rack 2 , a sliding piece 22 and an elastic structure 3 .

[0045] The housing 10 includes an upper shell 101, a radial contraction section 102 and a lower shell 103 from top to bottom. The upper shell 101, the radial contraction section 102 and the lower shell 103 are integrally cast. The inner diameter of the upper shell 101 is smaller than the inner diameter of the lower shell 103. The upper shell 101 is fixed to the upper support insulator 104 by bolts, and a first O-ring 1011 is provided at the matching position between the upper shell 101 and the upper support insulator 104; the support cylinder 107 is coaxially arranged with the lower shell 103, and a flange 1071 is integrally formed on the outer wall of the lower end of the support cylinder 107, and an annular resin pad 1072 is provided on the upper surface of the flange 1071. The flange 1071 and the lower end of the lower shell 103 are fixed by the first bolt 10 8 fixed connection, specifically, the lower end of the lower shell 103 has a threaded hole 1081 matched with the first bolt 108, the screw head of the first bolt 108 presses against the lower surface of the flange 1071, and a second O-ring 1012 is provided at the matching position between the flange 1071 and the lower end of the lower shell 103; the flange 1071 and the lower support insulator 105 are fixed by bolts, and a third O-ring 1013 is provided at the matching position between the flange 1071 and the lower support insulator 105. By arranging the first O-ring 1011, the second O-ring 1012 and the third O-ring 1013, the sealing effect of the shell 10 is improved, thereby reducing the leakage of the insulating gas.

[0046] The vertical gap between the inner wall of the radial contraction section 102 and the upper end of the support tube 107 is a shielding gap, and the shielding gap is 3-7 mm.

[0047] The plurality of coils 106 are sequentially sleeved on the outside of the support tube 107 along the axial direction, and the lowest coil 106 is pressed against the resin pad 1072 .

[0048] like Figure 2 , Figure 3 As shown, a strip groove 1073 is axially penetrated through the outer circumferential surface of the support tube 107, and the strip grooves 1073 are evenly arranged along the circumference of the support tube 107, and the two opposite groove walls of the strip groove 1073 have a third rubber coating (not marked in the figure); the mating tooth assembly 1 includes a plurality of groups of first triangular teeth 11 evenly arranged along the circumference of the support tube 107, and a group of first triangular teeth 11 includes a plurality of first triangular teeth 11 evenly arranged along the axial direction of the support tube 107, and the first triangular teeth 11 are fixedly connected to the outer wall of the support tube 107. In this embodiment, the first triangular teeth 11 are integrally formed at the bottom of the strip groove 1073, that is, the strip groove 1073 and the first triangular teeth 11 can be formed by machining, and the inclined surface of the first triangular teeth 11 has a second rubber coating (not marked in the figure).

[0049] The rack 2 is parallel to the axis of the support tube 107, and the rack 2 has a plurality of second triangular teeth 21. The first triangular teeth 11 and the second triangular teeth 21 are both isosceles triangles. The surface of the rack 2 and the inclined surface of the second triangular teeth 21 have a first rubber coating (not shown in the figure). The rack 2 is slidably matched with the strip groove 1073, and the first rubber coating surface of the rack 2 is in contact with the third rubber coating surface of the strip groove 1073. The groove wall of the strip groove 1073 is not only used to limit the circumferential deflection of the rack 2, but also because the first rubber coating and the third rubber coating have a certain friction coefficient, there is a matching damping between the first rubber coating and the third rubber coating, so that after the rack 2 is assembled to the strip groove 1073, the rack 2 is not easy to fall out, so that the rack 2 can be deeply hidden in the strip groove 1073, so that the outer diameter of the virtual circle enclosed by each rack 2 is small, so as to facilitate the insertion of the coil 106.

[0050] The slide 22 is annular, and a slip ring 23 is integrally formed at the inner diameter of the slide 22 . The slip ring 23 is sleeved on the upper outer wall of the support tube 107 , so that the slide 22 can slide axially relative to the support tube 107 , and the upper end of each rack 2 abuts against the lower surface of the slide 22 .

[0051] like Figure 3 , Figure 4 As shown, the elastic structure 3 is installed on the inner wall of the radial contraction section 102. In this embodiment, the elastic structure 3 includes a connecting ring 31 and a plurality of first spring pieces 32. The connecting ring 31 and the inner wall of the radial contraction section 102 are fixed by a second bolt 30. The first spring pieces 32 are evenly arranged along the circumference of the support tube 107. One end of the first spring piece 32 is integrally connected to the connecting ring 31, and the other end of the first spring piece 32 is inclined downward and extends toward the axial direction of the support tube 107. The lower end of the first spring piece 32 elastically presses against the upper surface of the slide 22.

[0052] During installation, the rack 2 is installed on the outside of the support tube 107. At this time, the inclined surface of the second triangular tooth 21 is completely in contact with the inclined surface of the first triangular tooth 11, the radial distance between the rack 2 and the support tube 107 is the smallest, and the outer diameter of the virtual circle formed by each rack 2 is the smallest. The rack 2 is not easy to interfere with the coil 106, so it is easy to sleeve the coil 106 on the outside of the support tube 107. At this time, there is a radial gap between the rack 2 and the inner diameter of the coil 106, and then the slide 22 is sleeved on the inner diameter of the support tube 107. The upper end of the slide 22 is ensured to be in contact with the upper end of the rack 2 by the lower surface thereof, and then the support cylinder 107 is installed in the housing 10. By tightening the first bolt 108, the screw head of the first bolt 108 is in contact with the lower surface of the flange 1071, so as to drive the support cylinder 107 and the coil 106 to move upward relative to the housing 10. The slide 22 touches the end of the first elastic sheet 32 ​​during the upward movement of the support cylinder 107. The first elastic sheet 32 ​​accumulates elastic potential energy, and the elastic force of the first elastic sheet 32 ​​is applied downward to the slide 22 ( Figure 3The direction of the arrow in is the direction of elastic force application), the slide 22 forces the rack 2 to move downward to change the state where the second triangular tooth 21 inclined surface is completely fitted with the first triangular tooth 11 inclined surface to the state where the second triangular tooth 21 inclined surface is partially fitted with the first triangular tooth 11 inclined surface. At the same time, under the guidance of the first triangular tooth 11 inclined surface, the rack 2 moves radially outward along the support tube 107, and the outer diameter of the virtual circle formed by each rack 2 is the largest. The side wall of the rack 2 abuts against the inner circumference of the coil 106 to clamp each coil 106, thereby limiting the circumferential and radial movement of the coil 106. In addition, since the surface of the rack 2 has a first rubber coating, the friction coefficient of the first rubber coating is large, and the coil 106 is axially limited by friction, thereby greatly improving the installation stability of the coil 106, and no additional tooling is required. That is, in the process of installing the support tube 107, when the support tube 107 moves relative to the shell 10, the energy storage of the first elastic sheet 32 ​​is utilized to complete the fixation of the coil 106, which is more convenient.

[0053] Secondly, since the elastic force of the first spring piece 32 is always applied to the rack 2, during use or transportation, when the coil 106 vibrates radially or axially, the rack 2 has a vertical displacement tendency, and the second triangular teeth 21 of the rack 2 and the first triangular teeth 11 of the support tube 107 are relatively displaced, and the elastic structure 3 will buffer the displacement tendency of the rack 2, and the first rubber coating, the second rubber coating and the third rubber coating have a certain friction coefficient, that is, the rack 2 and the groove wall of the strip groove 1073 are relatively displaced and rubbed, and the second triangular teeth 21 of the rack 2 and the first triangular teeth 11 of the support tube 107 are relatively displaced and rubbed, and friction generates heat to convert the kinetic energy of vibration into frictional heat energy, thereby achieving a shock absorbing effect.

[0054] Example 2 The difference between Example 2 and Example 1 is as follows: Figure 5 As shown, the mating tooth assembly 1 further includes a resin sleeve 12 , a spline 1074 is protruding from the outer wall of the support cylinder 107 , and a keyway 13 mating with the spline 1074 is provided on the inner wall of the resin sleeve 12 .

[0055] The strip groove 1073 and the first triangular teeth 11 are both disposed on the outer wall of the resin sleeve 12 .

[0056] In this way, the resin sleeve 12 can be integrally injection molded, and its molding and manufacturing is relatively simple. The dimensional accuracy of the first triangular tooth 11 is relatively high, which can improve the displacement accuracy of the rack 2, thereby improving the fixing accuracy of the coil 106.

[0057] Example 3 The difference between Example 3 and Example 1 is that Figure 6 , Figure 7 , Figure 8As shown, the elastic structure 3 includes a connecting ring 31 and a plurality of second elastic sheets 33 . The connecting ring 31 is fixed to the inner wall of the radial contraction section 102 by a second bolt 30 . The second elastic sheets 33 are evenly arranged along the circumference of the support tube 107 .

[0058] The second elastic piece 33 includes a first inclined section 331, a first U-shaped bendable section 336, a second inclined section 332, a first return section 337, a third inclined section 333, a second U-shaped bendable section 338, a fourth inclined section 334, a second return section 339, a fifth inclined section 335 and a third return section 330 which are connected in sequence along a direction away from the connecting ring 31, wherein the first inclined section 331 and the second inclined section 332 are both inclined downward, the third inclined section 333 and the fourth inclined section 334 are both inclined upward, and the fifth inclined section 335 is inclined downward, and a protrusion 1021 is integrally formed on the inner wall of the radial contraction section 102, the protrusion 1021 is semicircular, and the protrusion 1021 abuts against the side of the fourth inclined section 334.

[0059] When the first bolt 108 is tightened, the screw head of the first bolt 108 abuts against the lower surface of the flange 1071 to drive the flange 1071 to move upward relative to the housing 10, thereby driving the support tube 107 and the coil 106 to move upward relative to the housing 10. During this process, the upper surface of the slide 22 first abuts against the outer arc surface of the third return segment 330 (at this time, the coil 106 has not yet contacted the first return segment 337, see Fig. 9 ), the elastic force of the fifth inclined section 335 forces the slide 22 to move downward through the third fold section 330, so as to change the state in which the inclined surfaces of the second triangular tooth 21 and the first triangular tooth 11 are completely in contact with each other to a state in which the inclined surfaces of the second triangular tooth 21 and the first triangular tooth 11 are partially in contact with each other. During this state switching process, under the guidance of the inclined surfaces of the first triangular tooth 11, the rack 2 moves radially outward along the support tube 107, thereby limiting the circumferential and radial movements of the coil 106.

[0060] , continue to tighten the first bolt 108 to drive the support tube 107 and the coil 106 to move upward, the fifth inclined section 335 continues to accumulate elastic potential energy to force the rack 2 to continue to move radially outward, the virtual circle formed by the racks 2 has the largest outer diameter, the side wall of the rack 2 abuts against the inner circumference of the coil 106 to clamp the coils 106, and the clamping force is getting stronger and stronger, and the surface of the coil 106 begins to abut against the outer arc surface of the first folding section 337 (see Figure 7), the first U-shaped bendable section 336 is elastically compressed, the second inclined section 332 and the third inclined section 333 are deflected upward, and the elastic force of the first U-shaped bendable section 336 passes through the second inclined section 332 and the first return section 337 to force the coils 106 to be axially compressed, so as to reduce the axial gap between the coils 106, thereby reducing the vibration and collision of the coils 106 caused by the axial gap of the coils 106. At the same time, the upward deflection of the third inclined section 333 will drive the fourth inclined section 334 and the fifth inclined section 335 to deflect downward with the protrusion 1021 as the fulcrum (at the same time, the second U-shaped bendable section 338 is elastically compressed), and the downwardly deflected fifth inclined section 335 further applies downward pressure to the slide 22 and the rack 2 through the third return section 330, thereby further improving the clamping force of the rack 2 on the coil 106, thereby improving the installation stability of the coil 106.

[0061] It can be understood that within the limited axial displacement space of the support tube 107 and the coil 106, the amount of elastic deformation triggered by the second spring piece 33 is limited, and by increasing the linkage between the second inclined section 332, the fourth inclined section 334, the fifth inclined section 335 and the protrusion 1021, the clamping force of the fifth inclined section 335 on the rack 2 is further increased, thereby greatly improving the installation stability of the coil 106 under limited conditions.

[0062] Example 4 The difference between Example 4 and Example 3 is as follows: Fig.10 As shown, the length of the fifth inclined section 335 of Embodiment 4 is smaller than that of the fifth inclined section 335 of Embodiment 3, and the thickness of the fifth inclined section 335 is smaller than that of the second inclined section 332 .

[0063] In addition, the elastic structure 3 also includes a force transmission rod 35, and the two force transmission rods 35 are respectively located on both sides of the width direction of the second inclined section 332. One end of the force transmission rod 35 is welded and fixed to the middle part of the side of the second inclined section 332, and the other end of the force transmission rod 35 is fixed with a plurality of one-way teeth 36 arranged at equal intervals along its own length direction. The one-way teeth 36 are right-angled triangles, and the tip of the one-way tooth 36 is arranged away from the second inclined section 332 compared to the thick end of the one-way tooth 36, and the side of the fifth inclined section 335 is stuck in the gap between two adjacent one-way teeth 36.

[0064] like Fig.11 As shown, there is a fitting gap between the lower end of the housing 10 and the flange 1071 , and a rubber ring 1082 is clamped in the fitting gap, and the rubber ring 1082 is located on the outside of the first rubber ring 1082 .

[0065] like Fig.12As shown in FIG. 1 , when the first bolt 108 is tightened, the screw head of the first bolt 108 abuts against the lower surface of the flange 1071 to drive the flange 1071 to move upward relative to the housing 10, thereby driving the support tube 107 and the coil 106 to move upward relative to the housing 10. During this process, the surface of the coil 106 first abuts against the outer arc surface of the first folded segment 337 (the upper surface of the slide 22 has not yet contacted the third folded segment 330, see FIG. 1 ). Fig.12 The first U-shaped flexible section 336 is elastically compressed, and the second inclined section 332 and the third inclined section 333 are deflected upward (see FIG. Fig.12 The second state diagram in the figure), the second inclined section 332 deflected upward drives the force transmission rod 35 to move relative to the fifth inclined section 335, and each one-way tooth 36 elastically avoids the fifth inclined section 335 in turn, and the elastic force of the first U-shaped easy-bend section 336 passes through the second inclined section 332 and the first return section 337 to force each coil 106 to be axially compressed, so as to reduce the axial gap between each coil 106, thereby reducing the vibration and collision of the coil 106 caused by the axial gap of the coil 106; continue to tighten the first bolt 108 to make the support cylinder 107 continue to move upward until the rubber ring 1082 is in a fully compressed state. During this process, the upper surface of the slide 22 abuts against the outer arc surface of the third return section 330 again, and the elastic force of the fifth inclined section 335 passes through the third return section 330 to force the slide 22 to move downward, so as to change the state where the inclined surface of the second triangular tooth 21 is completely in contact with the inclined surface of the first triangular tooth 11 to the state where the inclined surface of the second triangular tooth 21 is partially in contact with the inclined surface of the first triangular tooth 11 (see Fig.12 During the state switching process, under the guidance of the inclined surface of the first triangular tooth 11, the rack 2 moves radially outward along the support cylinder 107, thereby limiting the circumferential and radial movement of the coil 106; then loosen the first bolt 108 (see Fig.12 ), the support tube 107 and the coil 106 move downward until the rubber ring 1082 is in an incompletely compressed state (the compression degree of the rubber ring 1082 is 30% to 70% of the fully compressed state), and after the first folded section 337 loses the contact of the coil 106, the first folded section 337 has a movable space, so that the first U-shaped easy-bend section 336 recovers part of its elastic deformation, and the second inclined section 332 deflects downward (see Fig.12 As shown in the third state diagram in the figure, since the side of the second inclined section 332 is stuck in the thick end of the one-way tooth 36, the second inclined section 332 will drive the fifth inclined section 335 to deflect downward together, and the downwardly deflected fifth inclined section 335 further applies downward pressure to the slide 22 and the rack 2 through the third folded section 330, further improving the clamping force of the rack 2 on the coil 106, thereby improving the installation stability of the coil 106. Finally, there is a gap between the outer arc surface of the first folded section 337 and the coil 106, that is, the coil 106 is not subjected to axial pressure, thereby reducing the occurrence of axial compression of the coil 106.

[0066] To summarize the installation process, the second inclined section 332 first applies axial pressure to the coil 106 to compress the gap between the coils 106, and the fifth inclined section 335 then abuts the slide 22 to complete the outward expansion of the rack 2, and the rack 2 radially clamps the coil 106. Secondly, loosen the first bolt 108 to move the support tube 107 and the coil 106 downward to release the axial pressure on the coil 106 and reduce the pressure damage to the coil 106. At the same time, the force transmission rod 35 is used to make the fifth inclined section 335 and the second inclined section 332 form a whole, so that the elastic force of the fifth inclined section 335 and the elastic force of the first U-shaped bendable section 336 are superimposed on the rack 2, thereby further improving the clamping effect.

[0067] It can be understood that, within the limited axial displacement space of the support tube 107 and the coil 106, the elastic deformation amount triggered by the second spring piece 33 is limited, and by utilizing the different upward and downward movement steps of the support tube 107 and the coil 106, the compression of the axial gap between the coils 106 is first satisfied, and then the clamping of the coil 106 by the rack 2 is satisfied, and finally the linkage of the force transmission rod 35 is utilized to superimpose the elastic force of the fifth inclined section 335 and the elastic force of the first U-shaped bendable section 336, so that the clamping force of the rack 2 is further increased, thereby greatly improving the installation stability of the coil 106 under limited conditions, reducing the axial vibration collision between the coils 106, and reducing the compression injury caused by excessive axial pressure on the coil 106.

[0068] Example 5 The difference between Example 5 and Example 4 is that Fig.13 As shown, a slide groove 20 is opened at the upper end of the rack 2, and a slide bar 37 is connected to the slide groove 20 along the radial sliding direction of the support tube 107. That is, after the coil 106 is put on the outside of the support tube 107, the slide bar 37 and the slide plate 22 are inserted in sequence, so that the slide bar 37 is located between the coil 106 and the slide plate 22.

[0069] The upper surface of the slide bar 37 is fixed with a plurality of inclined spring pieces 372 evenly arranged along its length direction, and the lower surface of the slide 22 is fixed with a plurality of guide teeth 221 evenly arranged along its radial direction. The guide teeth 221 are right-angled triangles, and the inclined surfaces of the guide teeth 221 fit the inclined surfaces of the inclined spring pieces 372.

[0070] An elastic bent claw 371 is integrally formed at one end of the slide bar 37 , and a matching groove 15 for radially inserting the elastic bent claw 371 is provided on the outer wall of the support tube 107 .

[0071] During the downward movement of the slide 22 under the elastic force of the fifth inclined section 335, since the inclined surface of the guide tooth 221 of the slide 22 fits with the inclined surface of the inclined spring piece 372, the downward movement trend of the slide 22 will be converted into a trend of forcing the slide bar 37 to move radially inward along the support tube 107, so that the elastic bent claw 371 of the slide bar 37 is radially inserted into the matching groove 15. Specifically, the elastic bent claw 371 elastically avoids the protrusion in the matching groove 15, and the inner arc surface of the elastic bent claw 371 fits to the matching groove 15. 5 to complete the radial limitation of the slide bar 37. Since the slide bar 37 is located between the coil 106 and the slide sheet 22, the lower surface of the slide bar 37 fits the upper surface of the coil 106, and the slide bar 37 plays a filling role to limit the axial position of the coil 106. Therefore, even if the overall installation is completed and there is no pressure from the first return section 337 (after the first bolt 108 is loosened until the support tube 107 and the coil 106 move down a certain distance), the coil 106 can still maintain the axial limitation.

[0072] In addition, the inclined spring piece 372 is elastic, and the elastic potential energy accumulated in the inclined spring piece 372 will be applied to the sliding piece 22. The sliding piece 22 has a downward reaction force on the sliding bar 37. The downward reaction force is applied to the coil 106, so that the axial limiting force of the coil 106 is more elastic and moderate, so as to reduce the situation where the axial limiting force of the coil 106 is too large and causes the coil 106 to be crushed.

[0073] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A built-in current transformer, characterized in that: The invention comprises an upper support insulator (104), a housing (10), a lower support insulator (105), a support cylinder (107), a plurality of coils (106), a matching tooth assembly (1), a rack (2), a slide (22) and an elastic structure (3), wherein the support cylinder (107) is coaxially arranged with the housing (10), a flange (1071) is integrally formed on the outer wall of the lower end of the support cylinder (107), an annular resin pad (1072) is provided on the upper surface of the flange (1071), and the flange (1071) and the housing (106) are connected to each other. 0) is fixedly connected at the lower end by a first bolt (108), the lower end of the shell (10) has a threaded hole (1081) matched with the first bolt (108), and the screw head of the first bolt (108) is pressed against the lower surface of the flange (1071); the shell (10) includes a radial contraction section (102), and the vertical gap between the inner wall of the radial contraction section (102) and the upper end of the support tube (107) is a shielding gap; a plurality of coils (106) are sequentially sleeved on the outer side of the support tube (107) along the axial direction, and the lowest coil (10 6) is pressed against the resin pad (1072), the mating tooth assembly (1) comprises a plurality of first triangular teeth (11) uniformly arranged along the axial direction of the support tube (107), the first triangular teeth (11) are fixedly connected to the outer wall of the support tube (107), the rack (2) is parallel to the axis of the support tube (107), the surface of the rack (2) has a first rubber coating, the rack (2) has a plurality of second triangular teeth (21), the sliding sheet (22) is axially slidably matched with the support tube (107), and the upper end of each rack (2) is abutted against The lower surface of the sliding plate (22), the elastic structure (3) is installed on the inner wall of the radial contraction section (102), and the elastic force of the elastic structure (3) is used to force the rack (2) to move downward to change the state where the second triangular tooth (21) inclined surface and the first triangular tooth (11) inclined surface are completely in contact with each other to a state where the second triangular tooth (21) inclined surface and the first triangular tooth (11) inclined surface are partially in contact with each other. When the second triangular tooth (21) inclined surface and the first triangular tooth (11) inclined surface are partially in contact with each other, the side wall of the rack (2) abuts against the inner circumferential surface of the coil (106).

2. The built-in current transformer according to claim 1, characterized in that: The inclined surface of the first triangular tooth (11) has a second rubber coating, and the inclined surface of the second triangular tooth (21) has the first rubber coating.

3. The built-in current transformer according to claim 2, characterized in that: A strip groove (1073) is axially penetrated through the outer peripheral surface of the support tube (107), and the bottom of the strip groove (1073) is integrally formed with the first triangular tooth (11); two opposite groove walls of the strip groove (1073) have a third rubber coating, and the first rubber coating surface of the rack (2) is in contact with the third rubber coating surface of the strip groove (1073).

4. The built-in current transformer according to claim 2, characterized in that: The mating tooth assembly (1) further comprises a resin sleeve (12), the outer wall of the support tube (107) being provided with a spline (1074), and the inner wall of the resin sleeve (12) being provided with a keyway (13) mating with the spline (1074); a strip groove (1073) being axially penetrated through the outer wall of the resin sleeve (12), and the bottom of the strip groove (1073) being integrally formed with the first triangular tooth (11); two opposite groove walls of the strip groove (1073) being provided with a third rubber coating, and the first rubber coating surface of the rack (2) being in contact with the third rubber coating surface of the strip groove (1073).

5. The built-in current transformer according to any one of claims 1 to 4, characterized in that: The elastic structure (3) comprises a connecting ring (31) and a plurality of first elastic sheets (32); the connecting ring (31) is fixed to the inner wall of the radial contraction section (102) by a second bolt (30); the first elastic sheets (32) are evenly arranged along the circumference of the support tube (107); one end of the first elastic sheet (32) is integrally connected to the connecting ring (31); the other end of the first elastic sheet (32) is inclined downward and extends toward the axial direction of the support tube (107); the lower end of the first elastic sheet (32) is elastically pressed against the upper surface of the slide (22).

6. The built-in current transformer according to any one of claims 1 to 4, characterized in that: The elastic structure (3) comprises a connecting ring (31) and a plurality of second elastic sheets (33); the connecting ring (31) is fixed to the inner wall of the radial contraction section (102) by means of a second bolt (30); the second elastic sheets (33) are evenly arranged along the circumference of the support tube (107); the second elastic sheets (33) comprise a first inclined section (331), a first U-shaped easy-to-bend section (336), a second inclined section (332), a first folded section (337), a third inclined section (333), a second U-shaped easy-to-bend section (336) connected in sequence in a direction away from the connecting ring (31); 8), a fourth inclined section (334), a second folded section (339), a fifth inclined section (335) and a third folded section (330), wherein the first inclined section (331) and the second inclined section (332) are both arranged to be inclined downward, the third inclined section (333) and the fourth inclined section (334) are both arranged to be inclined upward, and the fifth inclined section (335) is arranged to be inclined downward, and a protrusion (1021) is fixed to the inner wall of the radial contraction section (102), and the protrusion (1021) abuts against the side surface of the fourth inclined section (334); when tightening the first bolt (1 08) to drive the support tube (107) and the coil (106) to move upward relative to the housing (10), the upper surface of the slide (22) first abuts against the outer arc surface of the third folded section (330), and the elastic force of the fifth inclined section (335) forces the slide (22) to move downward through the third folded section (330), so as to change the state where the inclined surface of the second triangular tooth (21) and the inclined surface of the first triangular tooth (11) are completely in contact with each other to a state where the inclined surface of the second triangular tooth (21) and the inclined surface of the first triangular tooth (11) are partially in contact with each other. At this time, the coil The surface of (106) is then in contact with the outer arc surface of the first folded section (337), the first U-shaped bendable section (336) is elastically compressed, the second inclined section (332) and the third inclined section (333) are deflected upward, and the elastic force of the first U-shaped bendable section (336) is passed through the second inclined section (332) and the first folded section (337) to force each coil (106) to be axially compressed, and the upward deflection of the third inclined section (333) will drive the fourth inclined section (334) and the fifth inclined section (335) to deflect downward with the protrusion (1021) as the fulcrum.

7. The built-in current transformer according to any one of claims 1 to 4, characterized in that: The elastic structure (3) comprises a connecting ring (31), a plurality of second elastic sheets (33) and a force transmission rod (35); the connecting ring (31) is fixed to the inner wall of the radial contraction section (102) by a second bolt (30); the second elastic sheets (33) are evenly arranged along the circumference of the support tube (107); the second elastic sheets (33) comprise a first inclined section (331), a first U-shaped easy-bend section (336), a second inclined section (332), a first folded section (337), a third inclined section (333), a second U-shaped easy-bend section (338), a fourth inclined section (339), and a first inclined section (331) connected in sequence in a direction away from the connecting ring (31). The first inclined section (331) and the second inclined section (332) are both arranged to be inclined downward, the third inclined section (333) and the fourth inclined section (334) are both arranged to be inclined upward, and the fifth inclined section (335) is arranged to be inclined downward. A protrusion (1021) is fixed to the inner wall of the radial contraction section (102), and the protrusion (1021) abuts against the side surface of the fourth inclined section (334); the two force transmission rods (35) are respectively located at the two ends of the second inclined section (332) in the width direction. On the side, one end of the force transmission rod (35) is welded and fixed to the middle part of the side of the second inclined section (332), and the other end of the force transmission rod (35) is fixed with a plurality of one-way teeth (36) arranged at equal intervals along its length direction, and the one-way teeth (36) are right-angled triangles, and the side of the fifth inclined section (335) is stuck in the one-way teeth (36); a rubber ring (1082) is provided at the matching gap between the lower end of the shell (10) and the flange (1071); when the first bolt (108) is tightened to drive the support tube (107) and the coil (106) relative to the shell (10), During the upward movement, the surface of the coil (106) first contacts the outer arc surface of the first folded section (337), the first U-shaped easy-bend section (336) is elastically compressed, the second inclined section (332) and the third inclined section (333) are deflected upward, the second inclined section (332) deflected upward drives the force transmission rod (35) to move relative to the fifth inclined section (335), each one-way tooth (36) elastically avoids the fifth inclined section (335) in turn, and the elastic force of the first U-shaped easy-bend section (336) passes through the second inclined section (332) and the first folded section (337) to force each coil (106) to be axially compressed;The first bolt (108) is continuously tightened to cause the support tube (107) to continue to move upward, and the upper surface of the slide (22) is again in contact with the outer arc surface of the third folded section (330). The elastic force of the fifth inclined section (335) passes through the third folded section (330) to force the slide (22) to move downward, so as to change the state where the inclined surface of the second triangular tooth (21) and the inclined surface of the first triangular tooth (11) are completely in contact with each other to a state where the inclined surface of the second triangular tooth (21) and the inclined surface of the first triangular tooth (11) are partially in contact with each other. At this time, the side wall of the rack (2) is in contact with the inner circumference of the coil (106) and the rubber ring (1082) is in a fully compressed state. The first bolt (108) is unscrewed, the support tube (107) and the coil (106) are moved down until the rubber ring (1082) is in an incompletely compressed state, the first U-shaped flexible section (336) recovers part of its elastic deformation, the second inclined section (332) deflects downward, and because the side of the second inclined section (332) is stuck on the thick end of the one-way tooth (36), the second inclined section (332) will drive the fifth inclined section (335) to deflect downward together, and there is a gap between the outer arc surface of the first folded section (337) and the coil (106), and the third folded section (330) maintains a state of elastically abutting against the sliding sheet (22). ; 8. The built-in current transformer according to claim 7, characterized in that: A slide groove (20) is provided at the upper end of the rack (2), and a slide bar (37) is connected to the slide groove (20) in a radially sliding manner along the support tube (107). The slide bar (37) is located between the coil (106) and the slide plate (22). An elastic bent claw (371) is integrally formed at one end of the slide bar (37). The slide bar (37) is provided with a plurality of inclined spring pieces (372) evenly arranged along its length direction. The outer wall of the support tube (107) is provided with a matching groove (15) for the elastic bent claw (371) to be radially inserted. A plurality of guide teeth (221) evenly arranged along its radial direction are fixed to the lower surface of the slide plate (22), and the inclined surface of the guide tooth (221) fits with the inclined surface of the inclined spring piece (372).

9. The built-in current transformer according to claim 1, characterized in that: The shielding gap is 3-7 mm.

10. The built-in current transformer according to claim 1, characterized in that: The shell (10) comprises, from top to bottom, an upper shell (101), the radial contraction section (102) and a lower shell (103); the inner diameter of the upper shell (101) is smaller than the inner diameter of the lower shell (103); the upper shell (101) is fixed to the upper support insulator (104) and a first O-ring (1011) is provided at the matching position; the lower shell (103) is fixedly connected to the flange (1071) by the first bolt (108) and a second O-ring (1012) is provided at the matching position; the flange (1071) is fixed to the lower support insulator (105) and a third O-ring (1013) is provided at the matching position.

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