An in-built current transformer

Abstract

The present application discloses an in-built current transformer, belonging to the technical field of current transformers. The in-built current transformer includes an upper support insulator, a housing, a lower support insulator, a support cylinder, a plurality of coils, a mating tooth assembly, a rack, a sliding piece and an elastic structure. The housing includes a radially contracting section, and the vertical gap between the inner wall of the radially contracting section and the upper port of the support cylinder is a shielding gap. The plurality of coils are sequentially sleeved on the outside of the support cylinder along the axial direction. The mating tooth assembly includes a plurality of first triangular teeth, and the first triangular teeth are fixedly connected to the outer wall of the support cylinder. The rack is parallel to the axis of the support cylinder, and the rack has a plurality of second triangular teeth. The upper ends of the respective racks abut against the lower surface of the sliding piece. The elastic force of the elastic structure is used to force the rack to move downward to change the state from the state where the inclined surfaces of the second triangular teeth are completely attached to the inclined surfaces of the first triangular teeth to the state where the inclined surfaces of the second triangular teeth are partially attached to the inclined surfaces of the first triangular teeth. The present application can improve the installation stability and convenience of the coils.

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:

[0007] An in-built current transformer includes an upper support insulator, a housing, a lower support insulator, a support cylinder, a plurality of coils, a mating tooth assembly, a rack, a sliding piece and an elastic structure. The support cylinder is coaxially arranged with the housing. A flange is integrally formed on the outer wall of the lower end of the support cylinder. A ring-shaped resin pad is provided on the upper surface of the flange. The flange is fixedly connected with the lower end of the housing through a first bolt. The lower end of the housing has a threaded hole for mating with the first bolt. The head of the first bolt abuts against the lower surface of the flange. The housing includes a radially shrinking section. The vertical gap between the inner wall of the radially shrinking section and the upper port of the support cylinder is a shielding gap. The plurality of coils are sequentially sleeved on the outer side of the support cylinder along the axial direction. The lowermost coil abuts against the resin pad. The mating tooth assembly includes a plurality of first triangular teeth uniformly arranged along the axial direction of the support cylinder. The first triangular teeth are fixedly connected with the outer wall of the support cylinder. The rack is parallel to the axis of the support cylinder. The surface of the rack has a first rubber coating. The rack has a plurality of second triangular teeth. The sliding piece is in sliding fit with the support cylinder along the axial direction. The upper end of each rack abuts against the lower surface of the sliding piece. The elastic structure is installed on the inner wall of the radially shrinking section. The elastic force of the elastic structure is used to force the rack to move downward to change the state from the state where the inclined surface of the second triangular tooth is completely attached to the inclined surface of the first triangular tooth to the state where the inclined surface of the second triangular tooth is partially attached to the inclined surface of the first triangular tooth. When the inclined surface of the second triangular tooth is partially attached to the inclined surface of the first triangular tooth, the side wall of the rack abuts against the inner peripheral surface of the coil.

[0008] Through the above technical solution, during installation, the rack is installed on the outer side of the support cylinder. At this time, the inclined surface of the second triangular tooth is completely attached to the inclined surface of the first triangular tooth. The radial distance between the rack and the support cylinder is the smallest. The outer diameter of the virtual circle formed by enclosing each rack is the smallest. The rack is not likely to interfere with the coil, so it is convenient to sleeve the coil on the outer side of the support cylinder. At this time, there is a radial gap between the rack and the inner diameter of the coil. Then the sliding piece is sleeved on the upper end of the support cylinder to ensure that the lower surface of the sliding piece abuts against the upper end of the rack. Then the support cylinder is installed in the housing. By tightening the first bolt, the support cylinder and the coil are driven to move upward relative to the housing. When the sliding piece touches the elastic structure during the upward movement of the support cylinder with the support cylinder, the elastic structure stores elastic potential energy. The elastic force of the elastic structure is applied downward on the sliding piece. The sliding piece forces the rack to move downward to change the state from the state where the inclined surface of the second triangular tooth is completely attached to the inclined surface of the first triangular tooth to the state where the inclined surface of the second triangular tooth is partially attached to the inclined surface of the first triangular tooth. At the same time, under the guidance of the inclined surface of the first triangular tooth, the rack moves radially outward along the support cylinder. The outer diameter of the virtual circle formed by enclosing each rack is the largest. The side wall of the rack abuts against the inner peripheral surface of the coil to clamp each coil, thereby restricting the circumferential and radial movement of the coil. Moreover, since the surface of the rack has a first rubber coating and the friction coefficient of the first rubber coating is relatively large, axial positioning of the coil is achieved through friction, thus greatly improving the installation stability of the coil. And no additional tooling is required, that is, during the installation process of the support cylinder, when the support cylinder moves relative to the housing, the energy storage of the elastic structure is utilized to complete the fixation of the coil, which is relatively convenient.

[0009] Moreover, during use or transportation, the elastic force of the elastic structure is always applied to the rack. When the coil undergoes radial vibration, the rack has a tendency to displace vertically. The elastic structure will buffer the displacement tendency of the rack, and the vertical displacement of the rack will cause friction with the coil, converting the kinetic energy of the vibration into frictional heat energy, thereby achieving the damping effect.

[0010] 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.

[0011] Through the above technical solution, when the coil undergoes radial vibration and the second triangular tooth of the rack and the first triangular tooth of the support cylinder undergo relative displacement, due to the certain friction coefficient of the first rubber coating and the second rubber coating, frictional heat is generated during their relative displacement, converting the kinetic energy of the vibration into frictional heat energy, thereby achieving the damping effect.

[0012] Optionally, a strip-shaped groove is axially penetrated through the outer peripheral surface of the support cylinder, and the first triangular tooth is integrally formed at the bottom of the strip-shaped groove; the two opposite groove walls of the strip-shaped groove have a third rubber coating, and the surface of the first rubber coating of the rack is attached to the surface of the third rubber coating of the strip-shaped groove.

[0013] Through the above technical solution, by setting the cooperation of the strip-shaped groove and the rack, it can limit the rack circumferentially along the support cylinder. Moreover, the surface of the first rubber coating of the rack is attached to the surface of the third rubber coating of the strip-shaped groove. Since the first rubber coating and the third rubber coating have a certain friction coefficient, there is a cooperation damping between the first rubber coating and the third rubber coating, so that after the rack is assembled into the strip-shaped groove, the rack is not easily dropped out, facilitating the rack to be deeply hidden in the strip-shaped groove, and the outer diameter of the virtual circle formed by the enclosing of each rack is smaller, facilitating the sleeving of the coil.

[0014] Optionally, the mating tooth assembly further includes a resin sleeve. The outer wall of the support cylinder is provided with splines, and the inner wall of the resin sleeve is provided with key grooves that cooperate with the splines; a strip-shaped groove is axially penetrated through the outer wall of the resin sleeve, and the first triangular tooth is integrally formed at the bottom of the strip-shaped groove; the two opposite groove walls of the strip-shaped groove have a third rubber coating, and the surface of the first rubber coating of the rack is attached to the surface of the third rubber coating of the strip-shaped groove.

[0015] Through the above technical solution, the resin sleeve is integrally injection-molded, its molding manufacturing is relatively simple, and the dimensional accuracy of the first triangular tooth is relatively high, which can improve the displacement accuracy of the rack, thereby improving the fixing accuracy of the coil.

[0016] Optionally, the elastic structure includes a connecting ring and a plurality of first elastic pieces. The connecting ring is fixed to the inner wall of the radially contracting section by a second bolt. The first elastic pieces are evenly arranged along the circumference of the support cylinder. One end of each first elastic piece is integrally formed and connected to the connecting ring. The other end of the first elastic piece extends obliquely downward and towards the axis direction of the support cylinder. The lower end of the first elastic piece elastically presses against the upper surface of the sliding piece.

[0017] Through the above technical solution, by providing a connecting ring, which is installed on the inner wall of the radially contracting section by a second bolt, the fixation between the plurality of first elastic pieces and the housing is realized, which is relatively convenient. Moreover, the plurality of first elastic pieces are evenly distributed, and can apply elastic force to the sliding piece more evenly, thereby improving the displacement stability of each rack.

[0018] Optionally, the elastic structure includes a connecting ring and a plurality of second elastic pieces. The connecting ring is fixed to the inner wall of the radially contracting section by a second bolt. The second elastic pieces are evenly arranged along the circumference of the support cylinder. The second elastic piece includes a first inclined section, a first U-shaped bendable section, a second inclined section, a first folded section, a third inclined section, a second U-shaped bendable section, a fourth inclined section, a second folded section, a fifth inclined section and a third folded section connected in sequence along the direction away from the connecting ring. 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. A convex block is fixed on the inner wall of the radially contracting section, and the convex block abuts against the side surface of the fourth inclined section. During the process of tightening the first bolt to drive the support cylinder and the coil to move upward relative to the housing, the upper surface of the sliding piece first abuts against the outer arc surface of the third folded section, and the elastic force of the fifth inclined section forces the sliding piece to move downward through the third folded section, so as to change the state from the complete fit of the second triangular tooth surface and the first triangular tooth surface to the partial fit of the second triangular tooth surface and the first triangular tooth surface. At this time, the surface of the coil abuts against the outer arc surface of the first folded section, the first U-shaped bendable section is elastically compressed, the second inclined section and the third inclined section deflect upward, and the elastic force of the first U-shaped bendable section forces each coil to be axially pressed through the second inclined section and the first folded section. Moreover, the upward deflection of the third inclined section will drive the fourth inclined section and the fifth inclined section to deflect downward with the convex block as the fulcrum.

[0019] Through the above technical solution, when the first bolt is tightened, the bolt head of the first bolt abuts against the lower surface of the flange, so as to drive the flange to move upward relative to the housing, thereby driving the support cylinder and the coil to move upward relative to the housing. During this process, the upper surface of the sliding piece first abuts against the outer arc surface of the third folded section (at this time, the coil has not contacted the first folded section), and the elastic force of the fifth inclined section forces the sliding piece to move downward through the third folded section, so as to change the state from the completely fitting state of the second triangular tooth inclined surface and the first triangular tooth inclined surface to the partially fitting state of the second triangular tooth inclined surface and the first triangular tooth inclined surface. During this state switching process, under the guidance of the first triangular tooth inclined surface, the rack moves radially outward along the support cylinder, thereby restricting the circumferential and radial movement of the coil; continue to tighten the first bolt to drive the support cylinder and the coil to move upward, and the fifth inclined section continues to accumulate elastic potential energy to force the rack to continue to move radially outward. The outer diameter of the virtual circle formed by the enclosure of each rack is the largest, and the side wall of the rack abuts against the inner circumferential surface of the coil to clamp each coil, and the clamping force is getting larger and larger. At the same time, the surface of the coil begins to abut against the outer arc surface of the first folded section, the first U-shaped bendable section is elastically compressed, the second inclined section and the third inclined section deflect upward, and the elastic force of the first U-shaped bendable section forces each coil to be axially compressed through the second inclined section and the first folded section, so as to reduce the axial gap between the coils, thereby reducing the occurrence of coil vibration and collision caused by the axial gap of the coils. At the same time, the upward deflection of the third inclined section will drive the fourth inclined section and the fifth inclined section to deflect downward with the convex block as the fulcrum, and the downward deflected fifth inclined section further exerts a downward pressure on the sliding piece 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. It can be understood that within the limited axial displacement space of the support cylinder and the coil, the elastic deformation amount triggered by the second elastic piece is limited. By increasing the linkage of the second inclined section, the fourth inclined section, the fifth inclined section and the convex block, the fifth inclined section further increases the clamping force on the rack, thereby greatly improving the installation stability of the coil under limited conditions.

[0020] 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.

[0021] Through the above technical solution, when tightening the first bolt, the bolt head of the first bolt abuts against the lower surface of the flange to drive the flange to move upward relative to the housing, thereby driving the support cylinder and the coil to move upward relative to the housing. During this process, the surface of the coil first abuts against the outer arc surface of the first folded section (the upper surface of the sliding piece has not yet contacted the third folded section), the first U-shaped bendable section is elastically compressed, the second inclined section and the third inclined section deflect upward, and the upwardly deflected second inclined section 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. Moreover, the elastic force of the first U-shaped bendable section passes through the second inclined section and the first folded section to force each coil to be axially compressed, so as to reduce the axial gap between the coils, thereby reducing the occurrence of coil vibration and collision caused by the axial gap of the coils; continue to tighten the first bolt to make the support cylinder continue to move upward until the rubber ring is in a fully compressed state. During this process, the upper surface of the sliding piece then abuts against the outer arc surface of the third folded section, and the elastic force of the fifth inclined section passes through the third folded section to force the sliding piece to move downward, so as to change the state from the completely fitting state of the second triangular tooth surface and the first triangular tooth surface to the partially fitting state of the second triangular tooth surface and the first triangular tooth surface. During this state switching process, under the guidance of the first triangular tooth surface, the rack moves radially outward along the support cylinder, thereby restricting the circumferential and radial movement of the coil; then loosen the first bolt, and the support cylinder and the coil move downward 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 folded section loses the abutment of the coil, the first folded section has a movable space, so that the first U-shaped bendable section recovers part of its elastic deformation, and the second inclined section deflects downward. Since the side of the second inclined section is stuck at 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 exerts a downward pressure on the sliding piece 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 damage to the coil.

[0022] In summary of the above installation process, the second inclined section first applies an axial pressure to the coil to compress the gap between the coils. Then, the fifth inclined section abuts against the sliding piece to complete the outward expansion of the rack. The rack radially clamps the coil. Secondly, the first bolt is loosened to lower the support cylinder and the coil, so as to relieve the axial pressure on the coil and reduce the damage to the coil. At the same time, the force transmission rod is used to integrate the fifth inclined section and the second inclined section, 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 cylinder and the coil, the elastic deformation amount triggered by the second elastic piece is limited. By using the different upward and downward movement steps of the support cylinder and the coil, first satisfying the compression of the axial gap between the coils, then satisfying the clamping of the coil by the rack, and finally using the linkage of the force transmission rod to superimpose the elastic force of the fifth inclined section and the elastic force of the first U-shaped bendable section, 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 damage caused by excessive axial pressure on the coil.

[0023] Optionally, a chute is provided at the upper end of the rack. A slide bar is slidably connected along the radial direction of the support cylinder in the chute. The slide bar is located between the coil and the sliding piece. An elastic bent claw is integrally formed at one end of the slide bar. The slide bar is provided with a plurality of inclined elastic pieces evenly arranged along its length direction. A matching groove for radially clamping the elastic bent claw is provided on the outer wall of the support cylinder. A plurality of guiding teeth evenly arranged along the radial direction of the sliding piece are fixed on the lower surface of the sliding piece. The inclined surface of the guiding tooth is attached to the inclined surface of the inclined elastic piece.

[0024] Through the above technical solution, during the downward movement of the sliding piece under the action of the elastic force of the fifth inclined section, since the inclined surface of the guiding tooth of the sliding piece is attached to the inclined surface of the inclined elastic piece, the downward movement trend of the sliding piece will be converted into a trend of forcing the slide bar to move radially inward along the support cylinder, so that the elastic bent claw of the slide bar is radially clamped into the matching groove to complete the radial limit of the slide bar. The slide bar is located between the coil and the sliding piece, and the slide bar plays a filling role to axially limit the coil. And the inclined elastic piece has elasticity, and the elastic potential energy accumulated by the inclined elastic piece 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 situation that the coil is damaged due to excessive axial limiting force of the coil.

[0025] Optionally, the shielding gap is 3-7 mm.

[0026] Optionally, the housing sequentially 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 that of the lower shell. The upper shell is fixed to the upper support insulator and a first O-ring is provided at this matching position. The lower shell is fixedly connected to the flange through the first bolt and a second O-ring is provided at this matching position. The flange is fixed to the lower support insulator and a third O-ring is provided at this matching position.

[0027] Through the above technical solution, the sealing performance of the housing can be improved, and the leakage of the insulating gas can be reduced.

[0028] The beneficial effects of this application are as follows:

[0029] 1. By providing a rack, a first triangular tooth, and an elastic structure, and using the cooperation between the first triangular tooth and the second triangular tooth to guide the rack to move radially outwards, the side wall of the rack abuts against the inner peripheral surface of the coil to clamp each coil, thereby restricting the circumferential and radial movement of the coil. Moreover, since the surface of the rack has a first rubber coating with a relatively large friction coefficient, axial limiting of the coil is achieved through friction, thus 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 housing, the energy storage of the elastic structure is utilized to complete the fixation of the coil, which is relatively 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 generate friction with the coil, converting the kinetic energy of the vibration into frictional heat energy, thereby achieving a shock absorption effect;

[0030] 2. The second inclined section first applies an axial pressure to the coil to compress the gap between the coils, and then the fifth inclined section abuts against the sliding piece to complete the outward expansion of the rack, and the rack radially clamps the coil. Secondly, loosen the first bolt to move the support cylinder and the coil downward to relieve the axial pressure on the coil and reduce coil damage. At the same time, use the transmission rod 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 cylinder and the coil, the elastic deformation amount triggered by the second elastic piece is limited. By using the different upward and downward movement steps of the support cylinder and the coil, first satisfying the compression of the axial gap between the coils, then satisfying the clamping of the coil by the rack, and finally using the linkage of the transmission rod to superimpose the elastic force of the fifth inclined section and the elastic force of the first U-shaped bendable section, 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 collision between the coils, and reducing the damage caused by excessive axial pressure on the coil. Description of the Drawings

[0031] Figure 1 is a cross-sectional view of the overall structure of Embodiment 1.

[0032] Figure 2 is Figure 1 a cross-sectional view taken along the A-A direction in

[0033] Figure 3 is Figure 1 a partial enlarged view at B in

[0034] Figure 4It is a schematic diagram of the elastic structure of Embodiment 1.

[0035] Figure 5 It is a cross-sectional view of the support cylinder of Embodiment 2.

[0036] Figure 6 It is a cross-sectional view of the overall structure of Embodiment 3.

[0037] Figure 7 It is Figure 6 a partial enlarged view at C in

[0038] Figure 8 It is a schematic diagram of the second elastic piece of Embodiment 3.

[0039] Figure 9 It is a schematic diagram of Embodiment 3 for showing the state where the support cylinder moves up to the preliminary contact state between the sliding piece and the third folded section.

[0040] Figure 10 It is a schematic diagram of the second elastic piece of Embodiment 4.

[0041] Figure 11 It is a partial cross-sectional view of Embodiment 4 for showing the mating relationship between the lower shell and the flange.

[0042] Figure 12 It is a schematic diagram of Embodiment 4 for showing the state change of the second elastic piece during the upward movement and after the retreat of the support cylinder.

[0043] Figure 13 It is a schematic diagram of Embodiment 4 for showing the state change of the cooperation between the guiding teeth and the inclined elastic piece during the upward movement of the support cylinder.

[0044] Description of 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, radially contracting section; 1021, bump; 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, mating groove; 20, sliding groove; 21, second triangular tooth; 22, sliding piece; 221, guiding tooth; 23, slip ring; 30, second bolt; 31, connecting ring; 32, first elastic piece; 33, second elastic piece; 330, third folded 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 bendable section; 337, first folded section; 338, second U-shaped bendable section; 339, second folded section; 35, force transmission rod; 36, one-way tooth; 37, sliding strip; 371, elastic bent claw; 372, inclined elastic piece. Detailed implementation manners

[0045] The following details the implementation manners of the present application, and examples of the implementation manners are shown in the appended Figures 1-13 drawings.

[0046] In the description of this specification, the description referring to the terms "certain implementation manners", "one implementation manner", "some implementation manners", "schematic implementation manners", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the implementation manner or example are included in at least one implementation manner or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same implementation manner or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more implementation manners or examples.

[0047] Embodiment 1

[0048] Embodiment 1 discloses a built-in current transformer. As Figure 1 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.

[0049] The housing 10 sequentially includes an upper housing 101, a radially contracting section 102, and a lower housing 103 from top to bottom. The upper housing 101, the radially contracting section 102, and the lower housing 103 are integrally cast. The inner diameter of the upper housing 101 is smaller than that of the lower housing 103. The upper housing 101 and the upper support insulator 104 are fixed by bolts, and a first O-ring 1011 is provided at the mating position between the upper housing 101 and the upper support insulator 104; the support cylinder 107 is coaxially arranged with the lower housing 103. A flange 1071 is integrally formed on the outer wall of the lower end of the support cylinder 107. A ring-shaped resin pad 1072 is provided on the upper surface of the flange 1071. The flange 1071 and the lower end of the lower housing 103 are fixedly connected by a first bolt 108. Specifically, the lower end of the lower housing 103 has a threaded hole 1081 for mating with the first bolt 108. The head of the first bolt 108 abuts against the lower surface of the flange 1071. And a second O-ring 1012 is provided at the mating position between the flange 1071 and the lower end of the lower housing 103; the flange 1071 and the lower support insulator 105 are fixed by bolts, and a third O-ring 1013 is provided at the mating position between the flange 1071 and the lower support insulator 105. By providing the first O-ring 1011, the second O-ring 1012, and the third O-ring 1013, the sealing effect of the housing 10 is improved, thereby reducing the leakage of insulating gas.

[0050] The vertical gap between the inner wall of the radially contracting section 102 and the upper port of the support cylinder 107 is a shielding gap, and the shielding gap is 3 - 7 mm.

[0051] A plurality of coils 106 are sequentially sleeved on the outer side of the support cylinder 107 along the axis, and the lowermost coil 106 abuts against the resin pad 1072.

[0052] As Figure 2 、 Figure 3 shown, strip-shaped grooves 1073 are axially penetrated on the outer peripheral surface of the support cylinder 107. The strip-shaped grooves 1073 are evenly arranged along the circumferential direction of the support cylinder 107. The two opposite groove walls of the strip-shaped grooves 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 cylinder 107. One group of first triangular teeth 11 includes a plurality of first triangular teeth 11 evenly arranged along the axis of the support cylinder 107. The first triangular teeth 11 are fixedly connected to the outer wall of the support cylinder 107. In this embodiment, the first triangular teeth 11 are integrally formed on the bottom of the strip-shaped grooves 1073, that is, the strip-shaped grooves 1073 and the first triangular teeth 11 can be formed by turning. The inclined surface of the first triangular teeth 11 has a second rubber coating (not marked in the figure).

[0053] The rack 2 is parallel to the axis of the support cylinder 107. The rack 2 has a plurality of second triangular teeth 21. Both the first triangular teeth 11 and the second triangular teeth 21 are isosceles triangles. The surface of the rack 2 and the inclined surfaces of the second triangular teeth 21 both have a first rubber coating (not marked in the figure). The rack 2 is in sliding fit with the strip-shaped groove 1073, and the surface of the first rubber coating of the rack 2 is in contact with the surface of the third rubber coating of the strip-shaped groove 1073. The groove walls of the strip-shaped groove 1073 not only limit the circumferential deflection of the rack 2, but also, due to the certain friction coefficient between the first rubber coating and the third rubber coating, there is a fitting damping between the first rubber coating and the third rubber coating, so that after the rack 2 is assembled into the strip-shaped groove 1073, the rack 2 is not easy to fall out, so that the rack 2 can be deeply hidden in the strip-shaped groove 1073, making the outer diameter of the virtual circle formed by enclosing each rack 2 smaller, so as to facilitate the sleeving of the coil 106.

[0054] The sliding piece 22 is annular. A sliding ring 23 is integrally formed at the inner diameter of the sliding piece 22. The sliding ring 23 is sleeved on the outer wall of the upper end of the support cylinder 107, so that the sliding piece 22 can axially slide relative to the support cylinder 107, and the upper ends of the racks 2 abut against the lower surface of the sliding piece 22.

[0055] As Figure 3 、 Figure 4 shown, the elastic structure 3 is installed on the inner wall of the radially contracting section 102. In this embodiment, the elastic structure 3 includes a connecting ring 31 and a plurality of first elastic pieces 32. The connecting ring 31 is fixed to the inner wall of the radially contracting section 102 by a second bolt 30. The first elastic pieces 32 are evenly arranged along the circumference of the support cylinder 107. One end of the first elastic piece 32 is integrally connected to the connecting ring 31, and the other end of the first elastic piece 32 extends obliquely downward and towards the axis direction of the support cylinder 107. The lower end of the first elastic piece 32 elastically presses against the upper surface of the sliding piece 22.

[0056] During installation, the rack 2 is installed on the outside of the support cylinder 107. At this time, the inclined surfaces of the second triangular teeth 21 are completely attached to the inclined surfaces of the first triangular teeth 11. The radial distance between the rack 2 and the support cylinder 107 is the smallest, and the outer diameter of the virtual circle formed by enclosing each rack 2 is the smallest. The rack 2 is not easy to interfere with the coil 106, so as to facilitate sleeving the coil 106 on the outside of the support cylinder 107. At this time, there is a radial gap between the rack 2 and the inner diameter of the coil 106. Then the sliding piece 22 is sleeved on the upper end of the support cylinder 107 to ensure that the lower surface of the sliding piece 22 abuts against the upper end of the rack 2. 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 abuts against the lower surface of the flange 1071 to drive the support cylinder 107 and the coil 106 to move upward relative to the housing 10. When the sliding piece 22 touches the end of the first elastic piece 32 during the upward movement with the support cylinder 107, the first elastic piece 32 stores elastic potential energy, and the elastic force of the first elastic piece 32 is applied downward to the sliding piece 22 ( Figure 3The direction of the arrow in ( ) is the direction of the elastic force application. The sliding piece 22 forces the rack 2 to move downward, changing the state from the complete fitting of the inclined surface of the second triangular tooth 21 and the inclined surface of the first triangular tooth 11 to the partial fitting state of the inclined surface of the second triangular tooth 21 and the inclined surface of the first triangular tooth 11. At the same time, under the guidance of the inclined surface of the first triangular tooth 11, the rack 2 moves radially outward along the support cylinder 107. The outer diameter of the virtual circle formed by the enclosing of each rack 2 is the largest. The side wall of the rack 2 abuts against the inner peripheral surface of the coil 106 to clamp each coil 106, thereby restricting the circumferential and radial movement of the coil 106. Moreover, since the surface of the rack 2 has a first rubber coating with a relatively large coefficient of friction, axial limit of the coil 106 is achieved through frictional force, greatly improving the installation stability of the coil 106. And no additional tooling is required. That is, during the installation process of the support cylinder 107, when the support cylinder 107 moves relative to the housing 10, the energy storage of the first elastic piece 32 is utilized to complete the fixation of the coil 106, which is relatively convenient.

[0057] Secondly, since the elastic force of the first elastic piece 32 is always applied to the rack 2, during use or transportation, when the coil 106 undergoes radial or axial vibration, the rack 2 has a vertical displacement tendency, and relative displacement occurs between the second triangular tooth 21 of the rack 2 and the first triangular tooth 11 of the support cylinder 107. 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 coefficient of friction, that is, relative displacement friction occurs between the rack 2 and the groove wall of the strip-shaped groove 1073, and relative displacement friction occurs between the second triangular tooth 21 of the rack 2 and the first triangular tooth 11 of the support cylinder 107. Friction generates heat to convert the kinetic energy of vibration into frictional heat energy, thereby achieving the damping effect.

[0058] Embodiment 2

[0059] The differences between Embodiment 2 and Embodiment 1 are as Figure 5 shown. The mating tooth assembly 1 further includes a resin sleeve 12. The outer wall of the support cylinder 107 is convexly provided with a spline 1074, and the inner wall of the resin sleeve 12 is provided with a keyway 13 that cooperates with the spline 1074.

[0060] Both the strip-shaped groove 1073 and the first triangular tooth 11 are provided on the outer wall of the resin sleeve 12.

[0061] In this way, the resin sleeve 12 can be integrally injection-molded. Its molding manufacturing is relatively simple, and 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 fixation accuracy of the coil 106.

[0062] Embodiment 3

[0063] The differences between Embodiment 3 and Embodiment 1 are that, as Figure 6 , Figure 7 ,Figure 8 As shown, the elastic structure 3 includes a connecting ring 31 and a plurality of second elastic pieces 33. The connecting ring 31 is fixed to the inner wall of the radial contraction section 102 by a second bolt 30, and the second elastic pieces 33 are evenly arranged along the circumference of the support cylinder 107.

[0064] The second elastic piece 33 includes, in a direction away from the connecting ring 31, a first inclined section 331, a first U-shaped bendable section 336, a second inclined section 332, a first folded section 337, a third inclined section 333, a second U-shaped bendable section 338, a fourth inclined section 334, a second folded section 339, a fifth inclined section 335, and a third folded section 330 that are connected in sequence. Among them, both the first inclined section 331 and the second inclined section 332 are inclined downward, both the third inclined section 333 and the fourth inclined section 334 are inclined upward, the fifth inclined section 335 is inclined downward, and a convex block 1021 is integrally formed on the inner wall of the radial contraction section 102. The convex block 1021 is semicircular, and the convex block 1021 abuts against the side surface of the fourth inclined section 334.

[0065] 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 cylinder 107 and the coil 106 to move upward relative to the housing 10. During this process, the upper surface of the sliding piece 22 first abuts against the outer arc surface of the third folded section 330 (at this time, the coil 106 has not contacted the first folded section 337, see Figure 9 ), and the elastic force of the fifth inclined section 335 passes through the third folded section 330 to force the sliding piece 22 to move downward, so as to change the state from the state where the inclined surface of the second triangular tooth 21 is completely attached to the inclined surface of the first triangular tooth 11 to the state where the inclined surface of the second triangular tooth 21 is partially attached to the inclined surface of the first triangular tooth 11. During this 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 restricting the circumferential and radial movement of the coil 106.

[0066] , continue to tighten the first bolt 108 to drive the support cylinder 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 outer diameter of the virtual circle formed by the enclosing of each rack 2 is the largest, and the side wall of the rack 2 abuts against the inner peripheral surface of the coil 106 to clamp each coil 106, and the clamping force is increasing, and the surface of the coil 106 begins to abut against the outer arc surface of the first folded 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 deflect upward, and the elastic force of the first U-shaped bendable section 336 passes through the second inclined section 332 and the first folding section 337 to force each coil 106 to be axially pressed tightly, so as to reduce the axial gap between the coils 106, thereby reducing the occurrence of vibration and collision of the coils 106 due to the existence of the axial gap between 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 bump 1021 as the fulcrum (simultaneously, the second U-shaped bendable section 338 is elastically compressed), and the downward-deflected fifth inclined section 335 further exerts a downward pressure on the sliding piece 22 and the rack 2 through the third folding section 330, further improving the clamping force of the rack 2 on the coil 106, thereby improving the installation stability of the coil 106.

[0067] It can be understood that within the limited axial displacement space of the support cylinder 107 and the coil 106, the elastic deformation amount triggered by the second elastic piece 33 is limited. By increasing the linkage of the second inclined section 332, the fourth inclined section 334, the fifth inclined section 335 and the bump 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.

[0068] Embodiment 4

[0069] The difference between Embodiment 4 and Embodiment 3 is as Figure 10 shown. The length of the fifth inclined section 335 in Embodiment 4 is less than the length of the fifth inclined section 335 in Embodiment 3, and the thickness of the fifth inclined section 335 is less than the thickness of the second inclined section 332.

[0070] Moreover, the elastic structure 3 further includes a force transmission rod 35. 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 fixedly welded to the middle of the side of the second inclined section 332, and a plurality of one-way teeth 36 arranged at equal intervals along the length direction of the force transmission rod 35 are fixed at the other end of the force transmission rod 35. The one-way teeth 36 are right-angled triangles, and the tip of the one-way tooth 36 is farther away from the second inclined section 332 than the thick end of the one-way tooth 36, and the side of the fifth inclined section 335 is stuck into the gap between two adjacent one-way teeth 36.

[0071] As Figure 11 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 at the fitting gap. The rubber ring 1082 is located outside the first rubber ring 1082.

[0072] As Figure 12As shown, when the first bolt 108 is tightened, the head of the first bolt 108 abuts against the lower surface of the flange 1071, driving the flange 1071 to move upward relative to the housing 10, thereby driving the support cylinder 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 section 337 (the upper surface of the sliding piece 22 has not yet contacted the third folded section 330, see Figure 12 in the first state diagram), the first U-shaped bendable section 336 is elastically compressed, and the second inclined section 332 and the third inclined section 333 deflect upward (see Figure 12 in the second state diagram). The upward-deflected second inclined section 332 drives the force transmission rod 35 to move relative to the fifth inclined section 335, and each one-way tooth 36 elastically gives way to the fifth inclined section 335 in turn. Moreover, the elastic force of the first U-shaped bendable section 336 passes through the second inclined section 332 and the first folded section 337 to force each coil 106 to be axially compressed, reducing the axial gap between the coils 106, thereby reducing the occurrence of vibration and collision of the coils 106 due to the axial gap of the coils 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 completely compressed state. During this process, the upper surface of the sliding piece 22 then abuts against the outer arc surface of the third folded section 330, and the elastic force of the fifth inclined section 335 passes through the third folded section 330 to force the sliding piece 22 to move downward, changing the state from the complete fit of the inclined surface of the second triangular tooth 21 and the inclined surface of the first triangular tooth 11 to the partial fit state of the inclined surface of the second triangular tooth 21 and the inclined surface of the first triangular tooth 11 (see Figure 12 in the second state diagram). During this 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 restricting the circumferential and radial movement of the coil 106; then loosen the first bolt 108 (see Figure 12 in the third state diagram), the support cylinder 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 complete compression). After the first folded section 337 loses the abutment of the coil 106, the first folded section 337 has room for movement, enabling the first U-shaped bendable section 336 to recover part of its elastic deformation, and the second inclined section 332 deflects downward (see Figure 12 in the third state diagram). Since the side of the second inclined section 332 is stuck at 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. The downward-deflected fifth inclined section 335 further exerts a downward pressure on the sliding piece 22 and the rack 2 through the third folded section 330, further increasing 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 crushing of the coil 106.

[0073] In summary of the above installation process, the second inclined section 332 first applies an axial pressure to the coil 106 to compress the gap between the coils 106, and then the fifth inclined section 335 abuts against the sliding piece 22 to complete the outward expansion of the rack 2. The rack 2 radially clamps the coil 106. Secondly, the first bolt 108 is loosened to move the support cylinder 107 and the coil 106 downward to relieve the axial pressure on the coil 106 and reduce the bruising of the coil 106. At the same time, the force transmission rod 35 is used to form an integral body of the fifth inclined section 335 and the second inclined section 332, 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 to further improve the clamping effect.

[0074] It can be understood that within the limited axial displacement space of the support cylinder 107 and the coil 106, the elastic deformation amount triggered by the second elastic piece 33 is limited. By using the different upward and downward movement steps of the support cylinder 107 and the coil 106, first satisfying the compression of the axial gap between the coils 106, then satisfying the clamping of the coil 106 by the rack 2, and finally using the linkage of the force transmission rod 35 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 and collision between the coils 106, and reducing the bruising caused by excessive axial pressure of the coil 106.

[0075] Embodiment 5

[0076] The difference between Embodiment 5 and Embodiment 4 is that, as Figure 13 shown, a sliding groove 20 is opened at the upper end of the rack 2, and a sliding bar 37 is slidably connected along the radial direction of the support cylinder 107 in the sliding groove 20. That is, after the coil 106 is sleeved outside the support cylinder 107, the sliding bar 37 and the sliding piece 22 are sequentially placed, so that the sliding bar 37 is located between the coil 106 and the sliding piece 22.

[0077] A plurality of inclined elastic pieces 372 are uniformly arranged along the length direction of the upper surface of the sliding bar 37, and a plurality of guiding teeth 221 are uniformly arranged along the radial direction of the lower surface of the sliding piece 22. The guiding teeth 221 are right-angled triangles, and the inclined surfaces of the guiding teeth 221 are attached to the inclined surfaces of the inclined elastic pieces 372.

[0078] An elastic bent claw 371 is integrally formed at one end of the sliding bar 37, and a mating groove 15 for radially engaging the elastic bent claw 371 is provided on the outer wall of the support cylinder 107.

[0079] During the downward movement of the sliding piece 22 under the elastic force of the fifth inclined section 335, since the inclined surface of the guiding tooth 221 of the sliding piece 22 is in contact with the inclined surface of the inclined elastic piece 372, the downward movement trend of the sliding piece 22 will be converted into a trend of forcing the sliding bar 37 to move radially inward along the support cylinder 107, so that the elastic bent claws 371 of the sliding bar 37 are radially clamped into the fitting groove 15. Specifically, the elastic bent claws 371 elastically avoid the protrusions in the fitting groove 15, and the inner arc surface of the elastic bent claws 371 fits to the protrusions in the fitting groove 15 to complete the radial limit of the sliding bar 37. Since the sliding bar 37 is located between the coil 106 and the sliding piece 22, the lower surface of the sliding bar 37 fits to the upper surface of the coil 106, and the sliding bar 37 plays a filling role to axially limit the coil 106. Therefore, even after the overall installation is completed and without the pressing of the first folded section 337 (after the first bolt 108 is loosened and the support cylinder 107 and the coil 106 move down a certain distance), the coil 106 can still maintain the axially limited condition.

[0080] And the inclined elastic piece 372 has elasticity, and the elastic potential energy stored in the inclined elastic piece 372 will be applied to the sliding piece 22. The sliding piece 22 has a downward reaction force on the sliding bar 37, and this downward reaction force is applied to the coil 106, so that the axial limiting force of the coil 106 is relatively elastic and moderate, to reduce the occurrence of the situation that the coil 106 is crushed due to too large axial limiting force of the coil 106.

[0081] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to 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), the flange (1071) is fixedly connected to the lower end of the housing (10) by a first bolt (108), and the housing (10) is fixedly connected to the lower end of the housing (10). 10) has a threaded hole (1081) at the lower end thereof for cooperating with a first bolt (108), and the screw head of the first bolt (108) is pressed against the lower surface of the flange (1071); the housing (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 (106) is pressed against the resin pad (1072), and the mating tooth assembly (1) includes a plurality of uniformly arranged along the axial direction of the support tube (107) The first triangular tooth (11) is 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 slide (22) is axially slidably matched with the support tube (107); the upper end of each rack (2) abuts against the lower surface of the slide (22); the elastic structure (3) is installed on the inner wall of the radial contraction section (102); the elastic force of the elastic structure (3) is used to force the rack (2) to move downward so as to move the inclined surface of the second triangular tooth (21) The state of being completely in contact with the inclined surface of the first triangular tooth (11) is changed to a state of being partially in contact with the inclined surface of the second triangular tooth (21) and the inclined surface of the first triangular tooth (11). When 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, the side wall of the rack (2) abuts against the inner circumference of the coil (106); the elastic structure (3) comprises a connecting ring (31) and a plurality of second elastic sheets (33), the connecting ring (31) and the inner wall of the radial contraction section (102) are fixed by a second bolt (30), and the second elastic sheets (33) are evenly arranged along the circumference of the support tube (107);The second elastic piece (33) includes, in a direction away from the connecting ring (31), 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 (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 connected in sequence. ) are arranged to be inclined downward, the third inclined section (333) and the fourth inclined section (334) are 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 the first bolt (108) is tightened to drive the support tube (107) and the coil (106) to move upward relative to the housing (10), the 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 surface of the coil (106) abuts against the first folded section (337) again. ), the first U-shaped easy-to-bend section (336) is elastically compressed, the second inclined section (332) and the third inclined section (333) are deflected upward, the elastic force of the first U-shaped easy-to-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, and the upward deflection of the third inclined section (333) drives the fourth inclined section (334) and the fifth inclined section (335) to deflect downward with the protrusion (1021) as a fulcrum. ; 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 claim 1, characterized in that: The shielding gap is 3-7 mm.

6. 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.

Images