Mutual inductor and circuit breaker

Abstract

The utility model discloses a mutual inductor and a circuit breaker, and belongs to the technical field of low-voltage electrical appliances, the mutual inductor comprises an iron core group, an internal iron core, a first winding and a second winding, and the iron core group comprises the first iron core; the internal iron core is arranged in the inner ring of the first iron core; the first winding is wound on the iron core group and the internal iron core; and the second winding is wound on the inner iron core. According to the mutual inductor provided by the utility model, the iron core group, the internal iron core and the first winding wound on the iron core group and the internal iron core form an electromagnetic mutual inductance structure, the internal iron core and the second winding wound on the internal iron core form an electronic mutual inductance structure, and the internal iron core is arranged in the inner ring of the first iron core; therefore, the mutual inductor is compact in structure and small in occupied installation space, and miniaturization design of the circuit breaker is facilitated.

Description

Technical Field

[0001] This utility model relates to the field of low-voltage electrical technology, and in particular to a current transformer and a circuit breaker. Background Technology

[0002] For residual current operated circuit breakers, some products have two types of residual current protection circuit designs: electronic and electromagnetic, in order to improve the reliability of residual current operation. The design of the two types of residual current protection circuits must have zero-sequence current transformers for electronic residual current protection circuits and zero-sequence current transformers for electromagnetic residual current protection circuits.

[0003] In related technologies, the zero-sequence current transformer in the electronic residual current protection circuit and the zero-sequence current transformer in the electromagnetic residual current protection circuit are independent structural components. The zero-sequence current transformer in the electronic residual current protection circuit and the zero-sequence current transformer in the electromagnetic residual current protection circuit occupy a large installation space in the circuit breaker, which is not conducive to the miniaturization design of the circuit breaker. Utility Model Content

[0004] One objective of this invention is to provide a current transformer that requires little installation space, which is beneficial for the miniaturization design of circuit breakers.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A current transformer is provided, the current transformer comprising:

[0007] The core assembly includes the first core;

[0008] An internal iron core is located within the inner ring of the first iron core;

[0009] The first winding is wound on the core assembly and the inner core;

[0010] The second winding is wound on the inner iron core.

[0011] Optionally, the core assembly further includes a second core, which is disposed at one end of the first core.

[0012] Optionally, the core assembly further includes an insulating pad, wherein the first core, the inner core, and the second winding are all disposed on a first side of the insulating pad, and the second core is disposed on a second side of the insulating pad.

[0013] Optionally, it also includes:

[0014] A first housing, wherein a first positioning post and a positioning ring are provided inside the first housing, the first positioning post is provided with a first through hole along the axial direction, the first positioning post is located inside the positioning ring, an inner ring groove is formed between the first positioning post and the positioning ring, the internal iron core and the second winding are both provided in the inner ring groove, an outer ring groove is formed between the positioning ring and the side wall of the first housing, and the first iron core is provided in the outer ring groove;

[0015] The second cover is fitted together with the first cover. The second cover is provided with a second positioning post. The second positioning post is provided with a second through hole along the axial direction. An annular groove is formed between the second positioning post and the side wall of the second cover. The second iron core is disposed in the annular groove.

[0016] The first winding is wound around the first cover and the second cover through the first through hole and the second through hole.

[0017] Optionally, an elastic pad is provided in the annular groove, and the side of the second iron core opposite to the first iron core abuts against the elastic pad.

[0018] Optionally, the inner annular groove has a wire outlet channel on its groove wall, and both ends of the second winding extend out of the inner annular groove through the wire outlet channel.

[0019] Optionally, one of the first cover and the second cover has a protruding ring on the outer side wall, and the other has a retaining ring groove in the inner side wall, wherein the protruding ring engages with the retaining ring groove;

[0020] At least one of the first and second covers has a notch at the end of its side wall.

[0021] Optionally, it also includes:

[0022] A first outer casing, wherein a first column is provided inside the first outer casing, and the first column is provided with a first through hole along the axial direction;

[0023] The second outer casing has a second column inside it, and the second column has a second through hole along the axial direction;

[0024] The first column and the second column abut against each other, the first wire hole communicates with the second wire hole, and an annular receiving groove is formed between the first outer shell and the second outer shell. The first cover, the second cover and the first winding are all disposed in the annular receiving groove.

[0025] Optionally, one of the first housing and the second housing has a slot plate on its outer periphery, the slot plate having a slot, and the other housing has a snap-fit ​​protrusion on its outer periphery, the snap-fit ​​protrusion engaging with the slot.

[0026] One of the first column and the second column has a limiting protrusion at one end and a limiting groove at the other end, and the limiting protrusion is inserted into the limiting groove.

[0027] Another objective of this invention is to provide a circuit breaker, including the aforementioned current transformer.

[0028] Beneficial effects: The current transformer provided by this utility model has an electromagnetic current transformer structure consisting of an iron core assembly, an inner iron core, and a first winding wound on the iron core assembly and the inner iron core. The inner iron core and a second winding wound on the inner iron core form an electronic current transformer structure. This allows the current transformer to simultaneously function as a zero-sequence current transformer for both electronic and electromagnetic residual current protection circuits. Furthermore, by placing the inner iron core within the inner ring of the first iron core, the current transformer can be made compact in structure and occupy less installation space. Replacing the traditional zero-sequence current transformers for electronic and electromagnetic residual current protection circuits with this current transformer for installation within a circuit breaker is beneficial for the miniaturization design of the circuit breaker.

[0029] The circuit breaker provided by this utility model effectively reduces the structural size of the circuit breaker by incorporating a current transformer. Attached Figure Description

[0030] Figure 1 This is an exploded view of the structure of the current transformer provided by this utility model;

[0031] Figure 2 This is a schematic diagram of the structure of the current transformer provided by this utility model at the first winding;

[0032] Figure 3 This is a schematic diagram of the structure of the current transformer provided by this utility model at the second winding;

[0033] Figure 4 This is a partial structural cross-sectional view of the current transformer provided by this utility model;

[0034] Figure 5 This is a cross-sectional view of the first and second covers provided by this utility model;

[0035] Figure 6 This is a schematic diagram of the structure of the current transformer provided by this utility model;

[0036] Figure 7 This is a schematic diagram of the structure of the current transformer provided by this utility model inside the second housing;

[0037] Figure 8 This is a cross-sectional view of the first and second outer shells provided by this utility model.

[0038] In the picture:

[0039] 100. Iron core assembly; 110. First iron core; 120. Second iron core; 130. Insulating mat;

[0040] 200. Internal iron core;

[0041] 310. First winding; 320. Second winding;

[0042] 400, First cover; 401, Inner annular groove; 402, Outer annular groove; 403, Outlet channel; 4031, First channel section; 4032, Second channel section; 410, First positioning post; 411, First through hole; 420, Positioning ring; 430, Retaining ring groove; 440, Notch;

[0043] 500, Second cover; 501, Annular groove; 510, Second positioning post; 511, Second through hole; 520, Protruding ring; 530, Limiting surface; 540, Limiting ring;

[0044] 600, elastic pad;

[0045] 700, First outer casing; 701, Annular receiving groove; 702, Inlet hole; 710, First column; 711, First through hole; 712, Limiting protrusion; 720, First isolation plate; 730, Snap-fit ​​protrusion; 740, First clearance groove;

[0046] 800, Second outer shell; 810, Second column; 811, Second through hole; 812, Limiting groove; 820, Slot plate; 821, Slot; 830, Second clearance groove;

[0047] 900, Terminal piece; 910, Wire. Detailed Implementation

[0048] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0049] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0050] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0051] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0052] Reference Figures 1 to 4 As shown, this embodiment provides a current transformer, which includes an iron core assembly 100, an internal iron core 200, a first winding 310, and a second winding 320.

[0053] Specifically, the core assembly 100 includes a first core 110; an inner core 200 is disposed within the inner ring of the first core 110; a first winding 310 is wound on the core assembly 100 and the inner core 200; and a second winding 320 is wound on the inner core 200. It can be understood that the inner diameter of the first core 110 is larger than the outer diameter of the inner core 200.

[0054] In this embodiment, the core assembly 100, the inner core 200, and the first winding 310 wound on the core assembly 100 and the inner core 200 form an electromagnetic mutual inductance structure, while the inner core 200 and the second winding 320 wound on the inner core 200 form an electronic mutual inductance structure. This allows the transformer to simultaneously function as a zero-sequence transformer in both electronic and electromagnetic residual current protection circuits. Furthermore, by placing the inner core 200 within the inner ring of the first core 110, the transformer can be made compact in structure and occupy less installation space. Replacing the traditional zero-sequence transformers in electronic and electromagnetic residual current protection circuits with this transformer for installation within the circuit breaker facilitates the miniaturization design of the circuit breaker.

[0055] For example, the first iron core 110 and the inner iron core 200 can be arranged coaxially.

[0056] For example, the axial dimension of the first core 110 is larger than the axial dimension of the inner core 200.

[0057] Understandably, due to the compact structure of the current transformer, there is sufficient space within the circuit breaker to accommodate it, and the number or size of the iron cores in the iron core group 100 can be appropriately increased to improve the output characteristics of the electromagnetic current transformer structure, ensuring the stable and reliable operation of the trip unit in the electromagnetic residual current protection circuit, and guaranteeing electrical safety. The output characteristics of the electromagnetic current transformer structure can be the induced current of the first winding 310.

[0058] In this embodiment, reference continues to be made to... Figures 1 to 4 As shown, to achieve higher output characteristics in the electromagnetic mutual inductance structure, the core assembly 100 further includes a second core 120, which is located at one end of the first core 110. It can be understood that the first winding 310 is wound around the first core 110, the second core 120, and the inner core 200. Of course, the core assembly 100 may also include at least one additional core besides the first core 110 and the second core 120 to further enhance the output characteristics of the electromagnetic mutual inductance structure.

[0059] For example, the first iron core 110 and the second iron core 120 can be arranged coaxially.

[0060] In one feasible embodiment, the core assembly 100 further includes an insulating pad 130. The first core 110, the inner core 200, and the second winding 320 are all disposed on the first side of the insulating pad 130, and the second core 120 is disposed on the second side of the insulating pad 130. In this embodiment, the insulating pad 130 effectively prevents short-circuit interference between the inner core 200 and the second winding 320 and the second core 120 and the first winding 310.

[0061] For example, the insulating pad 130 may be an insulating paper.

[0062] For example, the inner diameter of the inner core 200 may be greater than or equal to the inner diameter of the second core 120.

[0063] For example, the axial dimension of the first core 110 is less than or equal to the axial dimension of the second core 120.

[0064] In one feasible implementation, to prevent short-circuiting interference between the internal core 200 and the second winding 320 and the second core 120 and the first winding 310, an insulating layer can be sprayed onto the internal core 200 and the second winding 320.

[0065] In one possible implementation, both the first winding 310 and the second winding 320 have an insulating varnish (not shown) to prevent short-circuit interference.

[0066] In this embodiment, reference is made to Figure 1 , Figure 4 and Figure 5 As shown, the current transformer also includes a first housing 400, in which a first positioning post 410 and a positioning ring 420 are provided. The first positioning post 410 has a first through hole 411 along the axial direction. The first positioning post 410 is located inside the positioning ring 420. An inner ring groove 401 is formed between the first positioning post 410 and the positioning ring 420. The internal iron core 200 and the second winding 320 are both disposed in the inner ring groove 401. An outer ring groove 402 is formed between the positioning ring 420 and the side wall of the first housing 400. The first iron core 110 is disposed in the outer ring groove 402 to realize the positioning and assembly of the first iron core 110, the internal iron core 200 and the second winding 320. The positioning ring 420 can prevent the internal iron core 200 and the second winding 320 from contacting and interfering with the first iron core 110.

[0067] Specifically, the current transformer also includes a second housing 500, which covers the first housing 400. The second housing 500 has a second positioning post 510 with a second through hole 511 along its axial direction. An annular groove 501 is formed between the second positioning post 510 and the side wall of the second housing 500. The second iron core 120 is disposed within the annular groove 501 to achieve positioning and assembly of the second iron core 120. Furthermore, the mutual covering of the first housing 400 and the second housing 500 provides protection for the first iron core 110, the second iron core 120, the inner iron core 200, and the second winding 320.

[0068] Specifically, the first winding 310 is wound on the first cover 400 and the second cover 500 through the first through hole 411 and the second through hole 511 to facilitate winding, and the second cover 500 and the first cover 400 can separate the first winding 310 and the second winding 320 to prevent short circuit interference.

[0069] In one feasible implementation, the second positioning post 510 extends into the inner ring of the inner core 200 and abuts against the first positioning post 410, facilitating the closing between the first cover 400 and the second cover 500.

[0070] In one feasible implementation, an elastic pad 600 is provided in the annular groove 501, and the side of the second iron core 120 away from the first iron core 110 abuts against the elastic pad 600, effectively preventing the first iron core 110, the second iron core 120 and the inner iron core 200 from being damaged by external forces such as vibration and impact on the transformer.

[0071] For example, the elastic pad 600 can be a sponge pad.

[0072] In one feasible embodiment, the inner annular groove 401 has a wire outlet channel 403 on its groove wall, and both ends of the second winding 320 extend out of the inner annular groove 401 through the wire outlet channel 403. In this embodiment, when assembling the electronic mutual inductance structure, the second winding 320 can first be wound on the inner iron core 200, and then the inner iron core 200 and the second winding 320 are placed in the inner annular groove 401, with both ends of the second winding 320 extending out of the inner annular groove 401 through the wire outlet channel 403, which facilitates assembly.

[0073] For example, the outgoing channel 403 can be L-shaped, including a first channel portion 4031 disposed on the bottom of the inner ring groove 401 and a second channel portion 4032 disposed on the first positioning post 410. The second channel portion 4032 passes through the end of the first positioning post 410 and communicates with the first through hole 411, so as to facilitate the second winding 320 to pass through.

[0074] In this embodiment, reference is made to Figure 1 , Figure 2 and Figure 5 As shown, the first cover 400 and the second cover 500 are snapped together, which makes it easier to disassemble and repair the iron core and windings compared to tape encapsulation.

[0075] Specifically, one of the first cover 400 and the second cover 500 has a protruding ring 520 on the outer side wall, and the other has a retaining ring groove 430 in the inner side wall. The protruding ring 520 is engaged with the retaining ring groove 430, which effectively ensures a stable and reliable connection between the first cover 400 and the second cover 500.

[0076] For example, the first cover 400 has a retaining ring groove 430 in the side wall, and the second cover 500 has a limiting surface 530 at the end of the side wall. The limiting surface 530 has a limiting ring 540, and the limiting ring 540 has a protruding ring 520 outside. The limiting ring 540 passes through the outer ring groove 402 and abuts against the bottom of the outer ring groove 402. The end of the side wall of the first cover 400 abuts against the limiting surface 530, thereby realizing the positioning and assembly between the first cover 400 and the second cover 500, and effectively ensuring the stable and reliable connection between the first cover 400 and the second cover 500.

[0077] In one possible implementation, at least one of the first housing 400 and the second housing 500 has a notch 440 at its sidewall end to facilitate separation of the first housing 400 and the second housing 500. For example, the first housing 400 has a notch 440 at its sidewall end.

[0078] In this embodiment, reference is made to Figure 1 , Figure 4 , Figures 6 to 8As shown, the current transformer also includes a first housing 700 and a second housing 800. The first housing 700 contains a first column 710 with a first through-hole 711 along its axial direction. The second housing 800 contains a second column 810 with a second through-hole 811 along its axial direction. The first column 710 and the second column 810 abut against each other, and the first through-hole 711 communicates with the second through-hole 811. An annular receiving groove 701 is formed between the first housing 700 and the second housing 800. The first cover 400, the second cover 500, and the first winding 310 are all disposed within the annular receiving groove 701, forming a protective structure. It is understood that the first through-hole 711 and the second through-hole 811 are used for the main circuit wiring of the circuit breaker.

[0079] Specifically, multiple first wire holes 711 are provided around the circumference of the first column 710, and multiple second wire holes 811 are provided around the circumference of the second column 810. The first wire holes 711 and the second wire holes 811 are arranged in a one-to-one correspondence. By setting multiple first wire holes 711 and multiple second wire holes 811, the main circuit lines are separated to form electrical isolation, effectively preventing short circuits and electrical breakdowns.

[0080] For example, a first isolation plate 720 is provided outside the first housing 700 between two adjacent first wiring holes 711 to form better electrical isolation. The first isolation plates 720 may intersect at one point.

[0081] For example, the second housing 800 is provided with a second isolation plate (not shown) between two adjacent second wiring holes 811 to form better electrical isolation. The second isolation plates may intersect at one point.

[0082] In this embodiment, reference is made to Figure 1 and Figure 8 As shown, the first outer shell 700 and the second outer shell 800 are snapped together for easy disassembly and assembly.

[0083] Specifically, one of the first outer shell 700 and the second outer shell 800 has a slot plate 820 on its outer periphery, with a slot 821 on the slot plate 820, and the other has a snap-fit ​​protrusion 730 on its outer periphery. The snap-fit ​​protrusion 730 snaps into the slot 821 to achieve snap-fit ​​between the first outer shell 700 and the second outer shell 800. In this embodiment, the slot plate 820 and the snap-fit ​​protrusion 730 are located outside the annular receiving groove 701 to prevent compression of the first cover 400, the second cover 500, and the first winding 310, resulting in a compact structure.

[0084] For example, the side wall end of the first housing 700 abuts against the side wall end of the second housing 800.

[0085] For example, the first housing 700 is provided with a snap-fit ​​protrusion 730, and the second housing 800 is provided with a snap-fit ​​plate 820.

[0086] For example, the first housing 700 is provided with a plurality of snap-fit ​​protrusions 730 spaced apart along the circumference, and the second housing 800 is provided with a plurality of snap-fit ​​plates 820 spaced apart along the circumference. The snap-fit ​​protrusions 730 and the snap-fit ​​plates 820 are arranged in a one-to-one correspondence to ensure that the connection between the first housing 700 and the second housing 800 is stable and reliable.

[0087] In one feasible embodiment, to facilitate the positioning and assembly between the first outer shell 700 and the second outer shell 800, one end of the first column 710 and the second column 810 is provided with a limiting protrusion 712, and the other end is provided with a limiting groove 812, with the limiting protrusion 712 inserted into the limiting groove 812. Optionally, the first column 710 is provided with a limiting protrusion 712, and the second column 810 is provided with a limiting groove 812.

[0088] For example, the cross-sectional shape of the limiting groove 812 and the limiting protrusion 712 includes, but is not limited to, polygonal or elliptical shapes.

[0089] In this embodiment, reference is made to Figures 6 to 8 As shown, the current transformer also includes a terminal block 900. The first winding 310 and the second winding 320 can be electrically connected to the terminal block 900. The terminal block 900 is electrically connected to the first winding 310 and the second winding 320 through four wires 910. In this embodiment, the terminal block 900 facilitates the electrical connection of the current transformer to the circuit.

[0090] For example, insulating sleeves (not shown) are provided at the electrical connection points of the first winding 310 and the corresponding wire 910, as well as at the electrical connection points of the second winding 320 and the corresponding wire 910, to prevent short-circuit interference.

[0091] In one feasible implementation, a first clearance groove 740 is provided in the side wall of the first housing 700, and a second clearance groove 830 is provided in the side wall of the second housing 800. The first clearance groove 740 and the second clearance groove 830 are arranged opposite to each other. In this embodiment, the wire 910 can extend into the first clearance groove 740 and the second clearance groove 830, so that neither the first winding 310 nor the second winding 320 extends outside the first housing 700 and the second housing 800, thus forming a protection.

[0092] For example, the sidewall of the first housing 700 protrudes outward at the first relief groove 740.

[0093] For example, the sidewall of the second housing 800 protrudes outward at the second relief groove 830.

[0094] For example, the first housing 700 and the second housing 800 have a wire inlet hole 702 formed between the first relief groove 740 and the second relief groove 830, and the wire 910 of the terminal 900 extends into the first relief groove 740 and the second relief groove 830 through the wire inlet hole 702.

[0095] This embodiment also provides a circuit breaker, including the aforementioned instrument transformer. In this embodiment, the electromagnetic residual current protection circuit of the circuit breaker is electrically connected to the first winding 310, and the electronic residual current protection circuit is electrically connected to the second winding 320, so as to replace the zero-sequence instrument transformer of the traditional electronic residual current protection circuit and the zero-sequence instrument transformer of the electromagnetic residual current protection circuit, effectively reducing the structural size of the circuit breaker.

[0096] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A transformer, characterized by The core group (100) further comprises a second core (120), and the second core (120) is arranged at one end of the first core (110). The core group (100) further comprises an insulating pad (130), and the first core (110), the inner core (200) and the second winding (320) are arranged on a first side of the insulating pad (130), and the second core (120) is arranged on a second side of the insulating pad (130). Further comprising: The first cover (400) is internally provided with a first positioning column (410) and a positioning ring (420), the first positioning column (410) is axially provided with a first through hole (411), the first positioning column (410) is located on the inner side of the positioning ring (420), an inner ring groove (401) is formed between the first positioning column (410) and the positioning ring (420), the inner core (200) and the second winding (320) are arranged in the inner ring groove (401), an outer ring groove (402) is formed between the positioning ring (420) and the side wall of the first cover (400), and the first core (110) is arranged in the outer ring groove (402); The second cover (500) is mutually covered with the first cover (400), the second cover (500) is provided with a second positioning column (510), the second positioning column (510) is axially provided with a second through hole (511), an annular groove (501) is formed between the second positioning column (510) and the side wall of the second cover (500), and the second core (120) is arranged in the annular groove (501); 2. The instrument transformer of claim 1, wherein, The first winding (310) is wound on the first cover (400) and the second cover (500) through the first through hole (411) and the second through hole (511).

3. The instrument transformer of claim 2, wherein, The annular groove (501) is internally provided with an elastic pad (600), and the side of the second core (120) away from the first core (110) is abutted against the elastic pad (600).

4. The instrument transformer of claim 2, wherein, The groove wall of the inner ring groove (401) is provided with a wire outlet channel (403), and the two ends of the second winding (320) are extended out of the inner ring groove (401) through the wire outlet channel (403). One of the side walls of the first cover (400) and the second cover (500) is externally provided with a convex ring (520), and the other is internally provided with a clamping ring groove (430), and the convex ring (520) is clamped with the clamping ring groove (430). The end of the side wall of at least one of the first cover (400) and the second cover (500) is provided with a notch (440). Further comprising:

5. The instrument transformer of claim 4, wherein, ​ 6. The instrument transformer of claim 4, wherein, ​ 7. The instrument transformer of claim 4, wherein, ​ ​ 8. The instrument transformer of claim 4, wherein, ​ A first shell (700) is internally provided with a first column (710) which is axially provided with a first threading hole (711); A second shell (800) is internally provided with a second column (810) which is axially provided with a second threading hole (811); Wherein, the first column (710) and the second column (810) abut, the first threading hole (711) and the second threading hole (811) are in communication, and an annular accommodating groove (701) is formed between the first shell (700) and the second shell (800), the first shell (700) and the second shell (800) are internally provided with the first column (710) and the second column (810), and the first column (710) and the second column (810) abut.

9. The instrument transformer of claim 8, wherein, The outer periphery of one of the first shell (700) and the second shell (800) is provided with a clamping groove plate (820) which is provided with a clamping groove (821), and the outer periphery of the other is provided with a clamping protrusion (730) which is clamped with the clamping groove (821); One end of one of the first column (710) and the second column (810) is provided with a limiting protrusion (712), and the other end of the other is provided with a limiting groove (812), and the limiting protrusion (712) is inserted into the limiting groove (812).

10. A circuit breaker characterized by, The transformer comprises the transformer according to any one of claims 1-9. The transformer comprises the transformer according to any one of claims 1-9.

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