Circuit breaker

Abstract

A circuit breaker (100) includes a housing (10) having a first cavity (11) and an arc-extinguishing chamber (12). A moving contact support (21) has a pivot axis and a rotating arm (212). The rotating arm (212) can rotate in the first cavity (11) and is provided with a moving contact point (2121). A fixed contact (30) is disposed on the housing (10) and a second end (302) of the fixed contact (30) extends to a first side of the arc-extinguishing chamber (12). The fixed contact (30) is provided with a fixed contact point (33). An arc-extinguishing grid sheet assembly (40) is disposed in the arc-extinguishing chamber (12) and includes first and second arc-extinguishing grid sheets (41, 42) respectively corresponding to the first and second sides of the arc-extinguishing chamber (12). The arc-extinguishing chamber (12) extends in an arcuate shape. A distance (L) between a side surface (121) of the arc-extinguishing chamber (12) facing towards the pivot axis and the pivot axis gradually increases in a direction from the first side to the second side of the arc-extinguishing chamber (12).

Description

FIELD

[0001] Embodiments of the present disclosure relate to the field of electrical equipment, and more particularly, to a circuit breaker.BACKGROUND

[0002] With the continuous improvement in DC (direct current) application voltage levels, the requirements for the breaking capacity of the circuit breakers are becoming higher and higher, and thus the requirements for the arc-extinguishing chambers are also becoming higher and higher. However, it is difficult for existing circuit breakers to meet the higher-level requirements for high-current breaking while improving the electrical life of low-current breaking.SUMMARY

[0003] An object of the present disclosure is to provide a circuit breaker to at least partially solve the above problems.

[0004] The present disclosure provides a circuit breaker, including: a housing provided with a first cavity and an arc-extinguishing chamber adjacent to each other inside; a moving contact support including a pivot connection part and a rotating arm extending from the pivot connection part, the pivot connection part having a pivot axis, the rotating arm being adapted to rotate in the first cavity, and an end of the rotating arm being provided with a moving contact point; a fixed contact disposed on the housing, where a first end of the fixed contact is located outside the housing, a second end of the fixed contact extends through the first cavity to a first side of the arc-extinguishing chamber, and the fixed contact is provided with a fixed contact point located in the first cavity; and an arc-extinguishing grid sheet assembly disposed in the arc-extinguishing chamber and including a first arc-extinguishing grid sheet and a second arc-extinguishing grid sheet, the first arc-extinguishing grid sheet corresponding to the first side of the arc-extinguishing chamber, and the second arc-extinguishing grid sheet corresponding to a second side of the arc-extinguishing chamber, and where the arc-extinguishing chamber extends in an arcuate shape, and a distance between a side surface of the arc-extinguishing chamber facing towards the pivot axis and the pivot axis gradually increases in a direction from the first side to the second side of the arc-extinguishing chamber.

[0005] In some embodiments, the housing is provided with an exhaust port, and the housing is further provided with a second cavity inside, where the second cavity is located at a side of the arc-extinguishing chamber away from the first cavity and is in communication with the exhaust port.

[0006] In some embodiments, an arc guide channel is disposed at the second end of the fixed contact and extends from the first side of the arc-extinguishing chamber to a first side of the second cavity, and a gap is formed between the second end of the fixed contact and the first arc-extinguishing grid sheet and between the arc guide channel and the first arc-extinguishing grid sheet.

[0007] In some embodiments, the arc guide channel includes a first arc guide surface, a portion of the fixed contact located in the arc-extinguishing chamber includes a second arc guide surface, where the second arc guide surface is connected to the first arc guide surface, and the second arc guide surface and the first arc guide surface are aligned with each other at a joint therebetween.

[0008] In some embodiments, the fixed contact includes a main body and an arc guide protrusion protruding from the main body to the first cavity and the arc-extinguishing chamber, the second arc guide surface is located on the arc guide protrusion, and the arc guide protrusion further includes a third arc guide surface extending from the second arc guide surface to a side wall of the fixed contact point.

[0009] In some embodiments, a width of the first cavity is less than a width of the arc-extinguishing chamber.

[0010] In some embodiments, a first side of the second cavity is adjacent to the first side of the arc-extinguishing chamber, a second side of the second cavity is adjacent to the second side of the arc-extinguishing chamber, and the exhaust port is located downstream of the second side of the second cavity, and a space of the second cavity gradually increases in a direction from the first side to the second side of the second cavity.

[0011] In some embodiments, the housing is further porvided with an exhaust passage inside, the second side of the second chamber is in communication with a first end of the exhaust passage through a curved passage, and a second end of the exhaust passage is in communication with the exhaust port.

[0012] In some embodiments, the housing is provided with a mounting cavity, two first cavities, two arc-extinguishing chambers, two second cavities, and two exhaust passages inside, and the housing is provided with two exhaust ports, where the two first cavities, the two arc-extinguishing chambers, and the two second cavities are located at two sides of the mounting cavity, each second cavity is in communication with the corresponding exhaust port through the corresponding exhaust passage, and the two exhaust ports are located at a same side of the housing and have a same opening direction; the moving contact support includes two rotating arms extending from the pivot connection part in opposite directions, the pivot connection part is located in the mounting cavity, each rotating arm is adapted to rotate in the corresponding first cavity, and the end of each rotating arm is provided with the moving contact point; the second end of each fixed contact of two fixed contacts passes through the corresponding first cavity to the first side of the corresponding arc-extinguishing chamber, and each fixed contact is provided with the fixed contact point; and two arc-extinguishing grid sheet assemblies are provided in the two arc-extinguishing chambers.

[0013] In some embodiments, the circuit breaker further includes: an arc guide sheet, a first end of the arc guide sheet being located at the second side of the arc-extinguishing chamber and being adjacent to the second arc-extinguishing grid sheet, and a second end of the arc guide sheet extending to a maximum opening position of the end of the rotating arm in the first cavity; and gas-generating sheets arranged at two sides of the rotating arm.

[0014] According to embodiments of the present disclosure, the second end of the fixed contact extends to the first side of the arc-extinguishing chamber, the fixed contact point is close to the first arc-extinguishing grid sheet of the arc-extinguishing grid sheet assembly located at the first side of the arc-extinguishing chamber, the arc-extinguishing chamber extends in an arcuate shape, the second arc-extinguishing grid sheet of the arc-extinguishing grid sheet assembly is located at the second side of the arc-extinguishing chamber and away from the fixed contact point, and a distance between the pivot axis and the side surface of the arc-extinguishing chamber facing towards the pivot axis of the moving contact support gradually increases in a direction from the first side to the second side of the arc-extinguishing chamber. In this way, during the process of the moving contact point being separated from the fixed contact point, as the rotating arm opens, a distance between the moving contact point and the arc-extinguishing grid sheets in the arc-extinguishing chamber gradually increases, so that the arc is unlikely to be transferred from the moving contact point to the arc-extinguishing grid sheets located at the middle position of the arc-extinguishing chamber midway through the opening of the rotating arm. Rather, when the rotating arm rotates to its maximum opening position, the arc is transferred from the moving contact point to the second arc-extinguishing grid sheet. Therefore, all arc-extinguishing grid sheets in the entire arc-extinguishing chamber can perform the arc-extinguishing function, thereby improving the utilization rate of each arc-extinguishing grid sheet of the arc-extinguishing grid sheet assembly. This enables the circuit breaker to meet the higher-level requirements for high-current breaking capacity while improving the electrical life of low-current breaking.

[0015] It should be understood that the content described in this content section is not intended to limit key features or important features of embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easy to understand through the following description.BRIEF DESCRIPTION OF DRAWINGS

[0016] The above and other features, advantages and aspects of embodiments of the present disclosure will become more apparent with reference to the accompanying drawings and the following detailed description. In the drawings, the same or similar reference numerals represent the same or similar elements, where: FIG. 1 shows a schematic diagram of an internal structure of a circuit breaker according to some embodiments of the present disclosure; FIG. 2 shows a partially enlarged schematic view of portion A of the circuit breaker shown in FIG. 1; and FIG. 3 shows a cross-sectional view of a circuit breaker according to some embodiments of the present disclosure, taken along section line C-C shown in FIG. 1. DETAILED DESCRIPTION

[0017] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0018] As used herein, the term "including" and its variants mean open-ended inclusion, i.e., "including but not limited to." The term "or" means "and / or" unless specifically stated otherwise. The term "based on" means "based at least in part on." The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment." The term "another embodiment" means "at least one further embodiment." The terms "first", "second", and the like may refer to different or identical objects.

[0019] As described above, it is difficult for existing circuit breakers to meet the electrical life requirements of low-current breaking while meeting the requirements for high-current breaking. Embodiments of the present disclosure provide a circuit breaker that can meet the electrical life requirements for the low-current breaking, and can also meet the higher-level requirements for high-current breaking capacity, thereby improving the breaking capacity of the circuit breaker. Hereinafter, the principle of the present disclosure will be described with reference to FIGS. 1 to 3.

[0020] FIG. 1 shows a schematic diagram of an internal structure of a circuit breaker 100 according to some embodiments of the present disclosure. The circuit breaker 100 shown in FIG. 1 is in an open state. FIG. 2 shows a partially enlarged schematic diagram of portion A of the circuit breaker 100 shown in FIG. 1. FIG. 3 shows a cross-sectional view of the circuit breaker 100 according to some embodiments of the present disclosure, taken along section line C-C shown in FIG. 1.

[0021] The circuit breaker 100 provided by embodiments of the present disclosure mainly includes a housing 10, a moving contact assembly 20, two fixed contacts 30, two arc-extinguishing grid sheet assemblies 40, and two arc guide sheets 50.

[0022] With reference to FIGS. 1 and 3, a mounting cavity 15 is centrally disposed inside the housing 10. Two first cavities 11, two arc-extinguishing chambers 12, and two second cavities 13 are provided at two sides of the mounting cavity 15. In some embodiments, the two first cavities 11, the two arc-extinguishing chambers 12, and the two second cavities 13 are arranged substantially centrosymmetrically with respect to the mounting cavity 15. Thus, the installation is simplified without the need for error-proof design, and the manufacturing cost can be effectively controlled. Specifically, by taking the structure located at the left side of the mounting cavity 15 as an example, the first cavity 11 is located between the mounting cavity 15 and the arc-extinguishing chamber 12, and the arc-extinguishing chamber 12 is located between the first cavity 11 and the second cavity 13. For ease of description, the first cavity 11 may also be referred to as a front cavity, and the second cavity 13 may also be referred to as a rear cavity.

[0023] The housing 10 is further provided with two exhaust ports, which are respectively designated as an exhaust port 101a and an exhaust port 101b. The housing 10 is further provided with two exhaust passages inside, which are respectively designated as an exhaust passage 14a and an exhaust passage 14b. Each second cavity 13 is in communication with the corresponding exhaust port through the corresponding exhaust passage. Specifically, the second cavity 13 on the left side is in communication with the exhaust port 101a through the exhaust passage 14a. The second cavity 13 on the right side is in communication with the exhaust port 101b through the exhaust passage 14b.

[0024] The moving contact assembly 20 may include a support body 22 and a moving contact support 21 supported by the support body 22. The support body 22 is disposed in the mounting cavity 15. The moving contact support 21 includes a middle pivot connection part 211 and two rotating arms 212 extending from the pivot connection part 211 in opposite directions. The pivot connection part 211 is pivotally connected to the support body 22 and located in the mounting cavity 15, and the pivot connection part 211 forms a pivot axis X-X of the moving contact support 21. The two rotating arms 212 are in one-to-one correspondence with the two first cavities 11 located at two sides of the mounting cavity 15. An end of each rotating arm 212 is provided with a moving contact point 2121.

[0025] The two fixed contacts 30 are arranged diagonally on the housing 10. A first end 301 of each fixed contact 30 is located outside the housing 10. The first end 301 of one fixed contact 30 is configured to be connected to a power supply, and the first end 301 of the other fixed contact 30 is configured to be connected to a load. The second end 302 of each fixed contact 30 extends through the corresponding first cavity 11 to a first side of the corresponding arc-extinguishing chamber 12. Each fixed contact 30 is provided with a fixed contact point 33, and each fixed contact point 33 is located in the corresponding first cavity 11. An arc guide channel 34 is disposed at the second end 302 of each fixed contact 30, and the arc guide channel 34 extends from the first side of the arc-extinguishing chamber 12 to a first side 131 of the second cavity 13. The arc guide channel 34 may be a metal part for arc guiding.

[0026] When the moving contact support 21 rotates about the pivot axis X-X, each rotating arm 212 can rotate about the pivot axis X-X in the corresponding first cavity 11. In FIG. 1, a circle to which the movement trajectory of the end of the rotating arm 212 belongs is denoted by the double-dot dash line B. As the moving contact support 21 rotates, the moving contact point 2121 on each rotating arm 212 can abut against or be separated from the corresponding fixed contact point 33, so as to correspond to a closed state or an open state of the circuit breaker 100 respectively.

[0027] Two arc-extinguishing grid sheet assemblies 40 are respectively disposed in the two arc-extinguishing chambers 12. Each arc-extinguishing grid sheet assembly 40 includes a plurality of stacked arc-extinguishing grid sheets. A gap through which the first cavity 11 is in communication with the second cavity 13 is formed between every two adjacent arc-extinguishing grid sheets of the plurality of arc-extinguishing grid sheets. The plurality of arc-extinguishing grid sheets include a first arc-extinguishing grid sheet 41 corresponding to the first side of the arc-extinguishing chamber 12, and a second arc-extinguishing grid sheet 42 corresponding to a second side of the arc-extinguishing chamber 12. That is, the first arc-extinguishing grid sheet 41 and the second arc-extinguishing grid sheet 42 are the two arc-extinguishing grid sheets located at two ends of the arc-extinguishing grid sheet assembly 40, and the other arc-extinguishing grid sheets are stacked between the first arc-extinguishing grid sheet 41 and the second arc-extinguishing grid sheet 42. The first arc-extinguishing grid sheet 41 is adjacent to the second end 302 of the corresponding fixed contact 30.

[0028] As can be seen from FIG. 1, each arc-extinguishing chamber 12 extends in an arcuate shape, and an extension direction of each arc-extinguishing grid sheet assembly 40 is consistent with an extension direction of the corresponding arc-extinguishing chamber 12. In some embodiments, the side edges of the plurality of arc-extinguishing grid sheets of each arc-extinguishing grid sheet assembly 40 facing towards the pivot axis X-X are attached to a side surface 121 of the arc-extinguishing chamber 12 facing towards the pivot axis X-X, and the side edges of the plurality of arc-extinguishing grid sheets facing away from the pivot axis X-X are attached to a side surface of the arc-extinguishing chamber 12 facing away from the pivot axis X-X.

[0029] Referring to FIG. 1, the distance L between the pivot axis X-X and the side surface 121 of each arc-extinguishing chamber 12 facing towards the pivot axis X-X gradually increases in a direction from the first side to the second side of the arc-extinguishing chamber 12. In other words, the extension direction of each arc-extinguishing chamber 12 from the first side to the second side gradually moves away from the movement trajectory of the corresponding moving contact point 2121. That is, during the rotation of the moving contact support 21, as each moving contact point 2121 gradually moves away from the corresponding fixed contact point 33, the distance between each moving contact point 2121 and the arc-extinguishing grid sheets in the corresponding arc-extinguishing chamber 12 gradually increases.

[0030] A first end of each arc guide sheet 50 is fixed to the second side of the corresponding arc-extinguishing chamber 12 and is adjacent to the second arc-extinguishing grid sheet 42. A second end of each arc guide sheet 50 extends to a maximum opening position of the end of the corresponding rotating arm 212 (see the position shown in FIG. 1) in the corresponding first cavity 11. The second end of each arc guide sheet 50 may be in a bent shape to be as close as possible to the corresponding moving contact point 2121.

[0031] In some embodiments, gas-generating sheets may be disposed in each first cavity 11. For example, the gas-generating sheets are disposed at two sides of the rotating arm 212. The gas-generating sheets may be plates containing gas-generating materials. In some embodiments, a magnetism-enhancing assembly may be disposed in each first cavity 11, and the magnetism-enhancing assembly may be arranged at two sides of the fixed contact point 33.

[0032] Hereinafter, the arc-extinguishing principle of the circuit breaker 100 provided by embodiments of the present disclosure will be described by taking the structure at the left side of the mounting cavity 15 in FIG. 1 as an example. The arc-extinguishing principle of the structure at the right side of the mounting cavity is similar to that of the structure at the left side.

[0033] Specifically, when the moving contact point 2121 is separated from the fixed contact point 33, an arc is generated between the moving contact point 2121 and the fixed contact point 33, the arc heats the surrounding air, and the gas-generating sheets generate a large amount of gas upon being heated by the arc. Therefore, a large amount of high-pressure gas is accumulated in the first cavity 11, flows to the arc-extinguishing chamber 12 and the second cavity 13, and then is exhausted from the exhaust port 101a through the exhaust passage 14a. The arc can enter the arc-extinguishing chamber 12 under the gas blowing effect and magnetic blowing effect to be extinguished. The arc that is not extinguished timely passes through the second cavity 13 and the exhaust passage 14a along with the air flow, and is exhausted from the exhaust port 101a.

[0034] It can be seen from FIG. 1 that when the moving contact point 2121 abuts against the fixed contact point 33, the distance between the moving contact point 2121 and the arc-extinguishing grid sheets in the arc-extinguishing chamber 12 reaches the minimum. When the rotating arm 212 performs an opening rotation to separate the moving contact point 2121 from the fixed contact point 33, the low-current arc can be easily guided into the arc-extinguishing chamber 12 as early as possible under the magnetic blowing effect and / or the gas blowing effect, and is extinguished timely upon contact with the arc-extinguishing grid sheets.

[0035] In addition, during the opening process of the rotating arm 212, as the distance between the moving contact point 2121 and the arc-extinguishing grid sheets in the arc-extinguishing chamber 12 gradually increases, it is beneficial to the movement of the arc. Therefore, the breaking capacity of the circuit breaker 100 is improved, so that the circuit breaker 100 can meet the electrical life requirements for the low-current breaking and the higher-level requirements for the high-current breaking capacity.

[0036] Specifically, during the opening process of the rotating arm 212, as the distance between the moving contact point 2121 and the arc-extinguishing grid sheets gradually increases, the arc is likely to be transferred from the moving contact point 2121 to the arc guide sheet 50 by means of the arc guide sheet 50 upon the rotating arm 212 rotating to the maximum opening position. Then, the arc comes into contact with the arc-extinguishing grid sheets (including the second arc-extinguishing grid sheet 42) at the second side of the arc-extinguishing chamber 12. Therefore, all arc-extinguishing grid sheets in the entire arc-extinguishing chamber 12 can perform the arc-extinguishing function, thereby improving the utilization rate of each arc-extinguishing grid sheet of the arc-extinguishing grid sheet assembly 40. Therefore, the circuit breaker 100 can meet the higher-level requirements for high-current breaking capacity while improving the electrical life of low-current breaking. The circuit breaker 100 of embodiments of the present disclosure effectively prevents the arc from breaking through the air midway through the opening of the rotating arm 212 and transferring from the moving contact point 2121 to the arc-extinguishing grid sheets at the middle position of the arc-extinguishing chamber 12. This would result in the arc-extinguishing grid sheets in the arc-extinguishing chamber 12 that are far away from the fixed contact point 33 failing to perform the arc-extinguishing function, thereby affecting the breaking capacity of the circuit breaker 100. By contrast, the circuit breaker 100 provided by embodiments of the present disclosure can greatly improve the electrical life of the low-current breaking, and can withstand the breaking of high short-circuit currents more than once, thereby improving the breaking capacity of the circuit breaker 100.

[0037] Referring to FIG. 2, in some embodiments, the arc guide channel 34 is closely attached to an outer side of the second end of the fixed contact 30, and the second end 302 of the fixed contact 30 and the arc guide channel 34 both face the first arc-extinguishing grid sheet 41, so that a gap 35 is formed between the second end 302 of the fixed contact 30 and the first arc-extinguishing grid sheet 41 and between the arc guide channel 34 and the first arc-extinguishing grid sheet 41. In this way, the high-pressure gas accumulated in the first cavity 11 can flow to the first side of the second cavity 13 through the gap 35. As the gas flows, the arc is driven to be transferred from the fixed contact point 33 to the arc guide channel 34 as soon as possible, enabling the arc to enter the arc-extinguishing chamber 12 as soon as possible and thus allowing the arc-extinguishing grid sheets (including the first arc-extinguishing grid sheet 41) located at the first side of the arc-extinguishing chamber 12 to come into contact with the arc as soon as possible, thereby fully perform their arc-extinguishing function.

[0038] Still referring to FIG. 2, in some embodiments, the arc guide channel 34 has a first arc guide surface 341, a portion of the fixed contact 30 located in the arc-extinguishing chamber 12 has a second arc guide surface 322, the second arc guide surface 322 is connected to the first arc guide surface 341, and the second arc guide surface 322 and the first arc guide surface 341 are aligned with each other at a joint therebetween. In some embodiments, the second arc guide surface 322 and the first arc guide surface 341 may be located on a same surface. In some embodiments, while the second arc guide surface 322 and the first arc guide surface 341 are aligned with each other at the joint therebetween, they may form a predetermined angle with respect to each other. The first arc guide surface 341 and second arc guide surface 322 aligned with each other at the joint will facilitate rapid movement of the arc from the second end 302 of the fixed contact 30 to the arc guide channel 34.

[0039] In some embodiments, the first arc guide surface 341 may be parallel to an outer surface 411 of the first arc-extinguishing grid sheet 41. In some embodiments, a predetermined angle may be formed between the first arc guide surface 341 and the outer surface 411 of the first arc-extinguishing grid sheet 41. In some embodiments, the predetermined angle formed between the first arc guide surface 341 and the outer surface 411 of the first arc-extinguishing grid sheet 41 may be, for example, equal to an angle formed between two opposite outer surfaces of every two adjacent arc-extinguishing grid sheets.

[0040] In some embodiments, in order to facilitate the alignment of the second arc guide surface 322 and the first arc guide surface 341 at the joint therebetween, a main body 31 of the fixed contact 30 is provided with an arc guide protrusion 32 protruding towards the first cavity 11 and the arc-extinguishing chamber 12, and the second arc guide surface 322 is located on the arc guide protrusion 32. In addition, the arc guide protrusion 32 may further include a third arc guide surface 323, and the third arc guide surface 323 extends from the second arc guide surface 322 to a side wall of the fixed contact point 33, thereby facilitating the rapid movement of the arc from the fixed contact point 33 to the arc guiding protrusion 32.

[0041] Referring back to FIG. 1, in some embodiments, taking the second cavity 13 on the left as an example, the first side 131 of the second cavity 13 is adjacent to the first side of the arc-extinguishing chamber 12, and the second side 132 of the second cavity 13 is adjacent to the second side of the arc-extinguishing chamber 12. The second side 132 of the second chamber 13 is in communication with the downstream exhaust port 101a through the corresponding exhaust passage 14a. A space of the second cavity 13 gradually increases in a direction from the first side 131 to the second side 132 of the second cavity 13. In this way, it is beneficial to form a reasonable pressure gradient in the second cavity 13, enabling the gas to flow smoothly from the first cavity 1, the arc-extinguishing chamber 12, and the second cavity 13 to the exhaust passage 14a, and finally flow out from the exhaust port 101a. Thus, the gas blowing efficiency is improved, the movement of the arc is accelerated, the arcing burning duration is reduced, and the arc-extinguishing effect of the arc-extinguishing chamber 12 is enhanced. The second cavity 13 on the right side is similar in structure to the second cavity 13 on the left side, and a space of the second cavity 13 gradually increases in a direction from the first side 131 to the second side 132 of the second cavity 13, thereby achieving a corresponding technical effect.

[0042] In some embodiments, the second side 132 of the second cavity 13 on the left side is in communication with a first end of the corresponding exhaust passage 14a through a curved passage, and a second end of the exhaust passage 14a is in communication with the corresponding exhaust port 101a. The second side 132 of the second cavity 13 on the right side is in communication with a first end of the corresponding exhaust passage 14b through a curved passage, and a second end of the exhaust passage 14b is in communication with the corresponding exhaust port 101b. By providing such exhaust passage 14a and exhaust passage 14b, the exhaust port 101a and the exhaust port 101b may be arranged at a same side of the housing 10, and the opening directions of the exhaust port 101a and the exhaust port 101b are allowed to be consistent. In this way, the circuit breaker 100 can be equipped with a single protective device to simultaneously manage the arc and metal particles flying out of each exhaust port, which helps reduce costs.

[0043] In some embodiments, each of the exhaust passage 14a and the exhaust passage 14b may include at least one bent segment to trap metal particles in the gas, thereby reducing the number of metal particles contained in the gas exhausted from each exhaust port of the circuit breaker 100.

[0044] Referring to FIG. 3, in some embodiments, a width W1 of the first cavity 11 is less than a width W2 of the arc-extinguishing chamber 12, and the width W1 of the first cavity 11 is less than a width W3 of the second cavity 13. In some embodiments, the width W1 of the first cavity 11 may be much smaller than the width W2 of the arc-extinguishing chamber 12, and the width W3 of the second cavity 13 may be slightly smaller than the width W2 of the arc interrupter 12. In this way, since the width of the first cavity 11 is relatively small, a narrow gap is thus formed, which facilitates the airflow in driving the arc to accelerate into the arc-extinguishing chamber 12. In addition, since the width of the arc-extinguishing chamber 12 and the width of the second cavity 13 are increased relative to the width of the first cavity 11, it is beneficial for the arc to fully fill the arc-extinguishing chamber 12, thereby helping improve utilization rate of the arc-extinguishing grid sheet assembly 40.

[0045] It is verified through experimental tests that the circuit breaker 100 according to embodiments of the present disclosure can withstand the breaking of high short-circuit currents two, three or even more times. In addition, the circuit breaker 100 of embodiments of the present disclosure significantly improves the electrical life of the low-current breaking of the circuit breaker 100, and significantly reduces the arcing burning duration.

[0046] It should be noted that, although the two first cavities 11, the two arc-extinguishing chambers 12, and the two second cavities 13 located at two sides of the mounting cavity 15 in embodiments of the present disclosure are arranged substantially centrosymmetrically, in some alternative embodiments, based on practical needs, the two first cavities 11, the two arc-extinguishing chambers 12, and the two second cavities 13 may have other arrangements, which are not limited to the centrosymmetric arrangement described in embodiments of the present disclosure. For example, in some alternative embodiments, the first cavity 11, the arc-extinguishing chamber 12, and the second cavity 13 located at a side of the mounting cavity 15 may adopt the structure according to embodiments of the present disclosure, and the first cavity 11, the arc-extinguishing chamber 12, and the second cavity 13 located at the other side of the mounting cavity 15 may adopt other suitable structures. In this way, the effect of improving electrical life of the low-current breaking of the circuit breaker 100 and enabling the circuit breaker 100 to meet the higher-level requirements for high-current breaking capacity can still be achieved.

[0047] As described above, in embodiments according to the present disclosure, the second end 302 of the fixed contact 30 extends to the first side of the arc-extinguishing chamber 12, the fixed contact point 33 is close to the first arc-extinguishing grid sheet 41 of the arc-extinguishing grid sheet assembly 40, the arc-extinguishing chamber 12 extends in an arcuate shape, the second arc-extinguishing grid sheet 42 of the arc-extinguishing grid sheet assembly 40 is away from the fixed contact point 33, and the distance L between the pivot axis X-X and the side surface 121 of the arc-extinguishing chamber 12 facing towards the pivot axis X-X of the moving contact support 21 gradually increases in the direction from the first side to the second side of the arc-extinguishing chamber 12. In this way, during the process of the moving contact point 2121 being separated from the fixed contact point 33, as the rotating arm 212 opens, the distance between the moving contact point 2121 and the arc-extinguishing grid sheets in the arc-extinguishing chamber 12 gradually increases, so that the arc is unlikely to be transferred from the moving contact point 2121 to the arc-extinguishing grid sheets located at the middle position of the arc-extinguishing chamber 12 midway through the opening of the rotating arm 212. Rather, when the rotating arm 212 rotates to its maximum opening position, the arc is transferred from the moving contact point 2121 to the second arc-extinguishing grid sheet 42 by means of the arc guide sheet 50. Therefore, all arc-extinguishing grid sheets in the entire arc-extinguishing chamber 12 can perform the arc-extinguishing function, thereby improving the utilization rate of each arc-extinguishing grid sheet of the arc-extinguishing grid sheet assembly 40. This enables the circuit breaker 100 to meet the higher-level requirements for high-current breaking capacity while improving the electrical life of low-current breaking.

[0048] In addition, by providing such arc guide channel 34 and the gap 35, designing the widths of the first cavity 11, the arc-extinguishing chamber 12, and the second cavity 13 of the circuit breaker 100, and designing the space size of the second cavity 13 from the first side 131 to the second side 132, it is beneficial to form a reasonable gas pressure gradient inside the circuit breaker 100, thereby achieving effective gas blowing to accelerate arc movement, and helping the arc to fully fill the arc-extinguishing chamber 12, thus improving the utilization rate of the arc-extinguishing grid sheet assembly 40 and improving the breaking capacity, arc-extinguishing capacity, and arc-extinguishing speed of the circuit breaker 100.

[0049] Various embodiments of the present disclosure have been described above, and the above description is illustrative, not exhaustive, and is not limited to embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope of the described embodiments. The selection of the terms used herein is intended to explain the principles of the embodiments, the practical application or technical improvements in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Examples

Embodiment Construction

[0017]Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0018]As used herein, the term "including" and its variants mean open-ended inclusion, i.e., "including but not limited to." The term "or" means "and / or" unless specifically stated otherwise. The term "based on" means "based at least in part on." The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment." The term "another embodiment" means "at least one further embodiment." The terms "first", "second", and the like...

FIELD

[0001] Embodiments of the present disclosure relate to the field of electrical equipment, and more particularly, to a circuit breaker.BACKGROUND

[0002] With the continuous improvement in DC (direct current) application voltage levels, the requirements for the breaking capacity of the circuit breakers are becoming higher and higher, and thus the requirements for the arc-extinguishing chambers are also becoming higher and higher. However, it is difficult for existing circuit breakers to meet the higher-level requirements for high-current breaking while improving the electrical life of low-current breaking.SUMMARY

[0003] An object of the present disclosure is to provide a circuit breaker to at least partially solve the above problems.

[0004] The present disclosure provides a circuit breaker, including: a housing provided with a first cavity and an arc-extinguishing chamber adjacent to each other inside; a moving contact support including a pivot connection part and a rotating arm extending from the pivot connection part, the pivot connection part having a pivot axis, the rotating arm being adapted to rotate in the first cavity, and an end of the rotating arm being provided with a moving contact point; a fixed contact disposed on the housing, where a first end of the fixed contact is located outside the housing, a second end of the fixed contact extends through the first cavity to a first side of the arc-extinguishing chamber, and the fixed contact is provided with a fixed contact point located in the first cavity; and an arc-extinguishing grid sheet assembly disposed in the arc-extinguishing chamber and including a first arc-extinguishing grid sheet and a second arc-extinguishing grid sheet, the first arc-extinguishing grid sheet corresponding to the first side of the arc-extinguishing chamber, and the second arc-extinguishing grid sheet corresponding to a second side of the arc-extinguishing chamber, and where the arc-extinguishing chamber extends in an arcuate shape, and a distance between a side surface of the arc-extinguishing chamber facing towards the pivot axis and the pivot axis gradually increases in a direction from the first side to the second side of the arc-extinguishing chamber.

[0005] In some embodiments, the housing is provided with an exhaust port, and the housing is further provided with a second cavity inside, where the second cavity is located at a side of the arc-extinguishing chamber away from the first cavity and is in communication with the exhaust port.

[0006] In some embodiments, an arc guide channel is disposed at the second end of the fixed contact and extends from the first side of the arc-extinguishing chamber to a first side of the second cavity, and a gap is formed between the second end of the fixed contact and the first arc-extinguishing grid sheet and between the arc guide channel and the first arc-extinguishing grid sheet.

[0007] In some embodiments, the arc guide channel includes a first arc guide surface, a portion of the fixed contact located in the arc-extinguishing chamber includes a second arc guide surface, where the second arc guide surface is connected to the first arc guide surface, and the second arc guide surface and the first arc guide surface are aligned with each other at a joint therebetween.

[0008] In some embodiments, the fixed contact includes a main body and an arc guide protrusion protruding from the main body to the first cavity and the arc-extinguishing chamber, the second arc guide surface is located on the arc guide protrusion, and the arc guide protrusion further includes a third arc guide surface extending from the second arc guide surface to a side wall of the fixed contact point.

[0009] In some embodiments, a width of the first cavity is less than a width of the arc-extinguishing chamber.

[0010] In some embodiments, a first side of the second cavity is adjacent to the first side of the arc-extinguishing chamber, a second side of the second cavity is adjacent to the second side of the arc-extinguishing chamber, and the exhaust port is located downstream of the second side of the second cavity, and a space of the second cavity gradually increases in a direction from the first side to the second side of the second cavity.

[0011] In some embodiments, the housing is further porvided with an exhaust passage inside, the second side of the second chamber is in communication with a first end of the exhaust passage through a curved passage, and a second end of the exhaust passage is in communication with the exhaust port.

[0012] In some embodiments, the housing is provided with a mounting cavity, two first cavities, two arc-extinguishing chambers, two second cavities, and two exhaust passages inside, and the housing is provided with two exhaust ports, where the two first cavities, the two arc-extinguishing chambers, and the two second cavities are located at two sides of the mounting cavity, each second cavity is in communication with the corresponding exhaust port through the corresponding exhaust passage, and the two exhaust ports are located at a same side of the housing and have a same opening direction; the moving contact support includes two rotating arms extending from the pivot connection part in opposite directions, the pivot connection part is located in the mounting cavity, each rotating arm is adapted to rotate in the corresponding first cavity, and the end of each rotating arm is provided with the moving contact point; the second end of each fixed contact of two fixed contacts passes through the corresponding first cavity to the first side of the corresponding arc-extinguishing chamber, and each fixed contact is provided with the fixed contact point; and two arc-extinguishing grid sheet assemblies are provided in the two arc-extinguishing chambers.

[0013] In some embodiments, the circuit breaker further includes: an arc guide sheet, a first end of the arc guide sheet being located at the second side of the arc-extinguishing chamber and being adjacent to the second arc-extinguishing grid sheet, and a second end of the arc guide sheet extending to a maximum opening position of the end of the rotating arm in the first cavity; and gas-generating sheets arranged at two sides of the rotating arm.

[0014] According to embodiments of the present disclosure, the second end of the fixed contact extends to the first side of the arc-extinguishing chamber, the fixed contact point is close to the first arc-extinguishing grid sheet of the arc-extinguishing grid sheet assembly located at the first side of the arc-extinguishing chamber, the arc-extinguishing chamber extends in an arcuate shape, the second arc-extinguishing grid sheet of the arc-extinguishing grid sheet assembly is located at the second side of the arc-extinguishing chamber and away from the fixed contact point, and a distance between the pivot axis and the side surface of the arc-extinguishing chamber facing towards the pivot axis of the moving contact support gradually increases in a direction from the first side to the second side of the arc-extinguishing chamber. In this way, during the process of the moving contact point being separated from the fixed contact point, as the rotating arm opens, a distance between the moving contact point and the arc-extinguishing grid sheets in the arc-extinguishing chamber gradually increases, so that the arc is unlikely to be transferred from the moving contact point to the arc-extinguishing grid sheets located at the middle position of the arc-extinguishing chamber midway through the opening of the rotating arm. Rather, when the rotating arm rotates to its maximum opening position, the arc is transferred from the moving contact point to the second arc-extinguishing grid sheet. Therefore, all arc-extinguishing grid sheets in the entire arc-extinguishing chamber can perform the arc-extinguishing function, thereby improving the utilization rate of each arc-extinguishing grid sheet of the arc-extinguishing grid sheet assembly. This enables the circuit breaker to meet the higher-level requirements for high-current breaking capacity while improving the electrical life of low-current breaking.

[0015] It should be understood that the content described in this content section is not intended to limit key features or important features of embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easy to understand through the following description.BRIEF DESCRIPTION OF DRAWINGS

[0016] The above and other features, advantages and aspects of embodiments of the present disclosure will become more apparent with reference to the accompanying drawings and the following detailed description. In the drawings, the same or similar reference numerals represent the same or similar elements, where: FIG. 1 shows a schematic diagram of an internal structure of a circuit breaker according to some embodiments of the present disclosure; FIG. 2 shows a partially enlarged schematic view of portion A of the circuit breaker shown in FIG. 1; and FIG. 3 shows a cross-sectional view of a circuit breaker according to some embodiments of the present disclosure, taken along section line C-C shown in FIG. 1. DETAILED DESCRIPTION

[0017] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0018] As used herein, the term "including" and its variants mean open-ended inclusion, i.e., "including but not limited to." The term "or" means "and / or" unless specifically stated otherwise. The term "based on" means "based at least in part on." The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment." The term "another embodiment" means "at least one further embodiment." The terms "first", "second", and the like may refer to different or identical objects.

[0019] As described above, it is difficult for existing circuit breakers to meet the electrical life requirements of low-current breaking while meeting the requirements for high-current breaking. Embodiments of the present disclosure provide a circuit breaker that can meet the electrical life requirements for the low-current breaking, and can also meet the higher-level requirements for high-current breaking capacity, thereby improving the breaking capacity of the circuit breaker. Hereinafter, the principle of the present disclosure will be described with reference to FIGS. 1 to 3.

[0020] FIG. 1 shows a schematic diagram of an internal structure of a circuit breaker 100 according to some embodiments of the present disclosure. The circuit breaker 100 shown in FIG. 1 is in an open state. FIG. 2 shows a partially enlarged schematic diagram of portion A of the circuit breaker 100 shown in FIG. 1. FIG. 3 shows a cross-sectional view of the circuit breaker 100 according to some embodiments of the present disclosure, taken along section line C-C shown in FIG. 1.

[0021] The circuit breaker 100 provided by embodiments of the present disclosure mainly includes a housing 10, a moving contact assembly 20, two fixed contacts 30, two arc-extinguishing grid sheet assemblies 40, and two arc guide sheets 50.

[0022] With reference to FIGS. 1 and 3, a mounting cavity 15 is centrally disposed inside the housing 10. Two first cavities 11, two arc-extinguishing chambers 12, and two second cavities 13 are provided at two sides of the mounting cavity 15. In some embodiments, the two first cavities 11, the two arc-extinguishing chambers 12, and the two second cavities 13 are arranged substantially centrosymmetrically with respect to the mounting cavity 15. Thus, the installation is simplified without the need for error-proof design, and the manufacturing cost can be effectively controlled. Specifically, by taking the structure located at the left side of the mounting cavity 15 as an example, the first cavity 11 is located between the mounting cavity 15 and the arc-extinguishing chamber 12, and the arc-extinguishing chamber 12 is located between the first cavity 11 and the second cavity 13. For ease of description, the first cavity 11 may also be referred to as a front cavity, and the second cavity 13 may also be referred to as a rear cavity.

[0023] The housing 10 is further provided with two exhaust ports, which are respectively designated as an exhaust port 101a and an exhaust port 101b. The housing 10 is further provided with two exhaust passages inside, which are respectively designated as an exhaust passage 14a and an exhaust passage 14b. Each second cavity 13 is in communication with the corresponding exhaust port through the corresponding exhaust passage. Specifically, the second cavity 13 on the left side is in communication with the exhaust port 101a through the exhaust passage 14a. The second cavity 13 on the right side is in communication with the exhaust port 101b through the exhaust passage 14b.

[0024] The moving contact assembly 20 may include a support body 22 and a moving contact support 21 supported by the support body 22. The support body 22 is disposed in the mounting cavity 15. The moving contact support 21 includes a middle pivot connection part 211 and two rotating arms 212 extending from the pivot connection part 211 in opposite directions. The pivot connection part 211 is pivotally connected to the support body 22 and located in the mounting cavity 15, and the pivot connection part 211 forms a pivot axis X-X of the moving contact support 21. The two rotating arms 212 are in one-to-one correspondence with the two first cavities 11 located at two sides of the mounting cavity 15. An end of each rotating arm 212 is provided with a moving contact point 2121.

[0025] The two fixed contacts 30 are arranged diagonally on the housing 10. A first end 301 of each fixed contact 30 is located outside the housing 10. The first end 301 of one fixed contact 30 is configured to be connected to a power supply, and the first end 301 of the other fixed contact 30 is configured to be connected to a load. The second end 302 of each fixed contact 30 extends through the corresponding first cavity 11 to a first side of the corresponding arc-extinguishing chamber 12. Each fixed contact 30 is provided with a fixed contact point 33, and each fixed contact point 33 is located in the corresponding first cavity 11. An arc guide channel 34 is disposed at the second end 302 of each fixed contact 30, and the arc guide channel 34 extends from the first side of the arc-extinguishing chamber 12 to a first side 131 of the second cavity 13. The arc guide channel 34 may be a metal part for arc guiding.

[0026] When the moving contact support 21 rotates about the pivot axis X-X, each rotating arm 212 can rotate about the pivot axis X-X in the corresponding first cavity 11. In FIG. 1, a circle to which the movement trajectory of the end of the rotating arm 212 belongs is denoted by the double-dot dash line B. As the moving contact support 21 rotates, the moving contact point 2121 on each rotating arm 212 can abut against or be separated from the corresponding fixed contact point 33, so as to correspond to a closed state or an open state of the circuit breaker 100 respectively.

[0027] Two arc-extinguishing grid sheet assemblies 40 are respectively disposed in the two arc-extinguishing chambers 12. Each arc-extinguishing grid sheet assembly 40 includes a plurality of stacked arc-extinguishing grid sheets. A gap through which the first cavity 11 is in communication with the second cavity 13 is formed between every two adjacent arc-extinguishing grid sheets of the plurality of arc-extinguishing grid sheets. The plurality of arc-extinguishing grid sheets include a first arc-extinguishing grid sheet 41 corresponding to the first side of the arc-extinguishing chamber 12, and a second arc-extinguishing grid sheet 42 corresponding to a second side of the arc-extinguishing chamber 12. That is, the first arc-extinguishing grid sheet 41 and the second arc-extinguishing grid sheet 42 are the two arc-extinguishing grid sheets located at two ends of the arc-extinguishing grid sheet assembly 40, and the other arc-extinguishing grid sheets are stacked between the first arc-extinguishing grid sheet 41 and the second arc-extinguishing grid sheet 42. The first arc-extinguishing grid sheet 41 is adjacent to the second end 302 of the corresponding fixed contact 30.

[0028] As can be seen from FIG. 1, each arc-extinguishing chamber 12 extends in an arcuate shape, and an extension direction of each arc-extinguishing grid sheet assembly 40 is consistent with an extension direction of the corresponding arc-extinguishing chamber 12. In some embodiments, the side edges of the plurality of arc-extinguishing grid sheets of each arc-extinguishing grid sheet assembly 40 facing towards the pivot axis X-X are attached to a side surface 121 of the arc-extinguishing chamber 12 facing towards the pivot axis X-X, and the side edges of the plurality of arc-extinguishing grid sheets facing away from the pivot axis X-X are attached to a side surface of the arc-extinguishing chamber 12 facing away from the pivot axis X-X.

[0029] Referring to FIG. 1, the distance L between the pivot axis X-X and the side surface 121 of each arc-extinguishing chamber 12 facing towards the pivot axis X-X gradually increases in a direction from the first side to the second side of the arc-extinguishing chamber 12. In other words, the extension direction of each arc-extinguishing chamber 12 from the first side to the second side gradually moves away from the movement trajectory of the corresponding moving contact point 2121. That is, during the rotation of the moving contact support 21, as each moving contact point 2121 gradually moves away from the corresponding fixed contact point 33, the distance between each moving contact point 2121 and the arc-extinguishing grid sheets in the corresponding arc-extinguishing chamber 12 gradually increases.

[0030] A first end of each arc guide sheet 50 is fixed to the second side of the corresponding arc-extinguishing chamber 12 and is adjacent to the second arc-extinguishing grid sheet 42. A second end of each arc guide sheet 50 extends to a maximum opening position of the end of the corresponding rotating arm 212 (see the position shown in FIG. 1) in the corresponding first cavity 11. The second end of each arc guide sheet 50 may be in a bent shape to be as close as possible to the corresponding moving contact point 2121.

[0031] In some embodiments, gas-generating sheets may be disposed in each first cavity 11. For example, the gas-generating sheets are disposed at two sides of the rotating arm 212. The gas-generating sheets may be plates containing gas-generating materials. In some embodiments, a magnetism-enhancing assembly may be disposed in each first cavity 11, and the magnetism-enhancing assembly may be arranged at two sides of the fixed contact point 33.

[0032] Hereinafter, the arc-extinguishing principle of the circuit breaker 100 provided by embodiments of the present disclosure will be described by taking the structure at the left side of the mounting cavity 15 in FIG. 1 as an example. The arc-extinguishing principle of the structure at the right side of the mounting cavity is similar to that of the structure at the left side.

[0033] Specifically, when the moving contact point 2121 is separated from the fixed contact point 33, an arc is generated between the moving contact point 2121 and the fixed contact point 33, the arc heats the surrounding air, and the gas-generating sheets generate a large amount of gas upon being heated by the arc. Therefore, a large amount of high-pressure gas is accumulated in the first cavity 11, flows to the arc-extinguishing chamber 12 and the second cavity 13, and then is exhausted from the exhaust port 101a through the exhaust passage 14a. The arc can enter the arc-extinguishing chamber 12 under the gas blowing effect and magnetic blowing effect to be extinguished. The arc that is not extinguished timely passes through the second cavity 13 and the exhaust passage 14a along with the air flow, and is exhausted from the exhaust port 101a.

[0034] It can be seen from FIG. 1 that when the moving contact point 2121 abuts against the fixed contact point 33, the distance between the moving contact point 2121 and the arc-extinguishing grid sheets in the arc-extinguishing chamber 12 reaches the minimum. When the rotating arm 212 performs an opening rotation to separate the moving contact point 2121 from the fixed contact point 33, the low-current arc can be easily guided into the arc-extinguishing chamber 12 as early as possible under the magnetic blowing effect and / or the gas blowing effect, and is extinguished timely upon contact with the arc-extinguishing grid sheets.

[0035] In addition, during the opening process of the rotating arm 212, as the distance between the moving contact point 2121 and the arc-extinguishing grid sheets in the arc-extinguishing chamber 12 gradually increases, it is beneficial to the movement of the arc. Therefore, the breaking capacity of the circuit breaker 100 is improved, so that the circuit breaker 100 can meet the electrical life requirements for the low-current breaking and the higher-level requirements for the high-current breaking capacity.

[0036] Specifically, during the opening process of the rotating arm 212, as the distance between the moving contact point 2121 and the arc-extinguishing grid sheets gradually increases, the arc is likely to be transferred from the moving contact point 2121 to the arc guide sheet 50 by means of the arc guide sheet 50 upon the rotating arm 212 rotating to the maximum opening position. Then, the arc comes into contact with the arc-extinguishing grid sheets (including the second arc-extinguishing grid sheet 42) at the second side of the arc-extinguishing chamber 12. Therefore, all arc-extinguishing grid sheets in the entire arc-extinguishing chamber 12 can perform the arc-extinguishing function, thereby improving the utilization rate of each arc-extinguishing grid sheet of the arc-extinguishing grid sheet assembly 40. Therefore, the circuit breaker 100 can meet the higher-level requirements for high-current breaking capacity while improving the electrical life of low-current breaking. The circuit breaker 100 of embodiments of the present disclosure effectively prevents the arc from breaking through the air midway through the opening of the rotating arm 212 and transferring from the moving contact point 2121 to the arc-extinguishing grid sheets at the middle position of the arc-extinguishing chamber 12. This would result in the arc-extinguishing grid sheets in the arc-extinguishing chamber 12 that are far away from the fixed contact point 33 failing to perform the arc-extinguishing function, thereby affecting the breaking capacity of the circuit breaker 100. By contrast, the circuit breaker 100 provided by embodiments of the present disclosure can greatly improve the electrical life of the low-current breaking, and can withstand the breaking of high short-circuit currents more than once, thereby improving the breaking capacity of the circuit breaker 100.

[0037] Referring to FIG. 2, in some embodiments, the arc guide channel 34 is closely attached to an outer side of the second end of the fixed contact 30, and the second end 302 of the fixed contact 30 and the arc guide channel 34 both face the first arc-extinguishing grid sheet 41, so that a gap 35 is formed between the second end 302 of the fixed contact 30 and the first arc-extinguishing grid sheet 41 and between the arc guide channel 34 and the first arc-extinguishing grid sheet 41. In this way, the high-pressure gas accumulated in the first cavity 11 can flow to the first side of the second cavity 13 through the gap 35. As the gas flows, the arc is driven to be transferred from the fixed contact point 33 to the arc guide channel 34 as soon as possible, enabling the arc to enter the arc-extinguishing chamber 12 as soon as possible and thus allowing the arc-extinguishing grid sheets (including the first arc-extinguishing grid sheet 41) located at the first side of the arc-extinguishing chamber 12 to come into contact with the arc as soon as possible, thereby fully perform their arc-extinguishing function.

[0038] Still referring to FIG. 2, in some embodiments, the arc guide channel 34 has a first arc guide surface 341, a portion of the fixed contact 30 located in the arc-extinguishing chamber 12 has a second arc guide surface 322, the second arc guide surface 322 is connected to the first arc guide surface 341, and the second arc guide surface 322 and the first arc guide surface 341 are aligned with each other at a joint therebetween. In some embodiments, the second arc guide surface 322 and the first arc guide surface 341 may be located on a same surface. In some embodiments, while the second arc guide surface 322 and the first arc guide surface 341 are aligned with each other at the joint therebetween, they may form a predetermined angle with respect to each other. The first arc guide surface 341 and second arc guide surface 322 aligned with each other at the joint will facilitate rapid movement of the arc from the second end 302 of the fixed contact 30 to the arc guide channel 34.

[0039] In some embodiments, the first arc guide surface 341 may be parallel to an outer surface 411 of the first arc-extinguishing grid sheet 41. In some embodiments, a predetermined angle may be formed between the first arc guide surface 341 and the outer surface 411 of the first arc-extinguishing grid sheet 41. In some embodiments, the predetermined angle formed between the first arc guide surface 341 and the outer surface 411 of the first arc-extinguishing grid sheet 41 may be, for example, equal to an angle formed between two opposite outer surfaces of every two adjacent arc-extinguishing grid sheets.

[0040] In some embodiments, in order to facilitate the alignment of the second arc guide surface 322 and the first arc guide surface 341 at the joint therebetween, a main body 31 of the fixed contact 30 is provided with an arc guide protrusion 32 protruding towards the first cavity 11 and the arc-extinguishing chamber 12, and the second arc guide surface 322 is located on the arc guide protrusion 32. In addition, the arc guide protrusion 32 may further include a third arc guide surface 323, and the third arc guide surface 323 extends from the second arc guide surface 322 to a side wall of the fixed contact point 33, thereby facilitating the rapid movement of the arc from the fixed contact point 33 to the arc guiding protrusion 32.

[0041] Referring back to FIG. 1, in some embodiments, taking the second cavity 13 on the left as an example, the first side 131 of the second cavity 13 is adjacent to the first side of the arc-extinguishing chamber 12, and the second side 132 of the second cavity 13 is adjacent to the second side of the arc-extinguishing chamber 12. The second side 132 of the second chamber 13 is in communication with the downstream exhaust port 101a through the corresponding exhaust passage 14a. A space of the second cavity 13 gradually increases in a direction from the first side 131 to the second side 132 of the second cavity 13. In this way, it is beneficial to form a reasonable pressure gradient in the second cavity 13, enabling the gas to flow smoothly from the first cavity 1, the arc-extinguishing chamber 12, and the second cavity 13 to the exhaust passage 14a, and finally flow out from the exhaust port 101a. Thus, the gas blowing efficiency is improved, the movement of the arc is accelerated, the arcing burning duration is reduced, and the arc-extinguishing effect of the arc-extinguishing chamber 12 is enhanced. The second cavity 13 on the right side is similar in structure to the second cavity 13 on the left side, and a space of the second cavity 13 gradually increases in a direction from the first side 131 to the second side 132 of the second cavity 13, thereby achieving a corresponding technical effect.

[0042] In some embodiments, the second side 132 of the second cavity 13 on the left side is in communication with a first end of the corresponding exhaust passage 14a through a curved passage, and a second end of the exhaust passage 14a is in communication with the corresponding exhaust port 101a. The second side 132 of the second cavity 13 on the right side is in communication with a first end of the corresponding exhaust passage 14b through a curved passage, and a second end of the exhaust passage 14b is in communication with the corresponding exhaust port 101b. By providing such exhaust passage 14a and exhaust passage 14b, the exhaust port 101a and the exhaust port 101b may be arranged at a same side of the housing 10, and the opening directions of the exhaust port 101a and the exhaust port 101b are allowed to be consistent. In this way, the circuit breaker 100 can be equipped with a single protective device to simultaneously manage the arc and metal particles flying out of each exhaust port, which helps reduce costs.

[0043] In some embodiments, each of the exhaust passage 14a and the exhaust passage 14b may include at least one bent segment to trap metal particles in the gas, thereby reducing the number of metal particles contained in the gas exhausted from each exhaust port of the circuit breaker 100.

[0044] Referring to FIG. 3, in some embodiments, a width W1 of the first cavity 11 is less than a width W2 of the arc-extinguishing chamber 12, and the width W1 of the first cavity 11 is less than a width W3 of the second cavity 13. In some embodiments, the width W1 of the first cavity 11 may be much smaller than the width W2 of the arc-extinguishing chamber 12, and the width W3 of the second cavity 13 may be slightly smaller than the width W2 of the arc interrupter 12. In this way, since the width of the first cavity 11 is relatively small, a narrow gap is thus formed, which facilitates the airflow in driving the arc to accelerate into the arc-extinguishing chamber 12. In addition, since the width of the arc-extinguishing chamber 12 and the width of the second cavity 13 are increased relative to the width of the first cavity 11, it is beneficial for the arc to fully fill the arc-extinguishing chamber 12, thereby helping improve utilization rate of the arc-extinguishing grid sheet assembly 40.

[0045] It is verified through experimental tests that the circuit breaker 100 according to embodiments of the present disclosure can withstand the breaking of high short-circuit currents two, three or even more times. In addition, the circuit breaker 100 of embodiments of the present disclosure significantly improves the electrical life of the low-current breaking of the circuit breaker 100, and significantly reduces the arcing burning duration.

[0046] It should be noted that, although the two first cavities 11, the two arc-extinguishing chambers 12, and the two second cavities 13 located at two sides of the mounting cavity 15 in embodiments of the present disclosure are arranged substantially centrosymmetrically, in some alternative embodiments, based on practical needs, the two first cavities 11, the two arc-extinguishing chambers 12, and the two second cavities 13 may have other arrangements, which are not limited to the centrosymmetric arrangement described in embodiments of the present disclosure. For example, in some alternative embodiments, the first cavity 11, the arc-extinguishing chamber 12, and the second cavity 13 located at a side of the mounting cavity 15 may adopt the structure according to embodiments of the present disclosure, and the first cavity 11, the arc-extinguishing chamber 12, and the second cavity 13 located at the other side of the mounting cavity 15 may adopt other suitable structures. In this way, the effect of improving electrical life of the low-current breaking of the circuit breaker 100 and enabling the circuit breaker 100 to meet the higher-level requirements for high-current breaking capacity can still be achieved.

[0047] As described above, in embodiments according to the present disclosure, the second end 302 of the fixed contact 30 extends to the first side of the arc-extinguishing chamber 12, the fixed contact point 33 is close to the first arc-extinguishing grid sheet 41 of the arc-extinguishing grid sheet assembly 40, the arc-extinguishing chamber 12 extends in an arcuate shape, the second arc-extinguishing grid sheet 42 of the arc-extinguishing grid sheet assembly 40 is away from the fixed contact point 33, and the distance L between the pivot axis X-X and the side surface 121 of the arc-extinguishing chamber 12 facing towards the pivot axis X-X of the moving contact support 21 gradually increases in the direction from the first side to the second side of the arc-extinguishing chamber 12. In this way, during the process of the moving contact point 2121 being separated from the fixed contact point 33, as the rotating arm 212 opens, the distance between the moving contact point 2121 and the arc-extinguishing grid sheets in the arc-extinguishing chamber 12 gradually increases, so that the arc is unlikely to be transferred from the moving contact point 2121 to the arc-extinguishing grid sheets located at the middle position of the arc-extinguishing chamber 12 midway through the opening of the rotating arm 212. Rather, when the rotating arm 212 rotates to its maximum opening position, the arc is transferred from the moving contact point 2121 to the second arc-extinguishing grid sheet 42 by means of the arc guide sheet 50. Therefore, all arc-extinguishing grid sheets in the entire arc-extinguishing chamber 12 can perform the arc-extinguishing function, thereby improving the utilization rate of each arc-extinguishing grid sheet of the arc-extinguishing grid sheet assembly 40. This enables the circuit breaker 100 to meet the higher-level requirements for high-current breaking capacity while improving the electrical life of low-current breaking.

[0048] In addition, by providing such arc guide channel 34 and the gap 35, designing the widths of the first cavity 11, the arc-extinguishing chamber 12, and the second cavity 13 of the circuit breaker 100, and designing the space size of the second cavity 13 from the first side 131 to the second side 132, it is beneficial to form a reasonable gas pressure gradient inside the circuit breaker 100, thereby achieving effective gas blowing to accelerate arc movement, and helping the arc to fully fill the arc-extinguishing chamber 12, thus improving the utilization rate of the arc-extinguishing grid sheet assembly 40 and improving the breaking capacity, arc-extinguishing capacity, and arc-extinguishing speed of the circuit breaker 100.

[0049] Various embodiments of the present disclosure have been described above, and the above description is illustrative, not exhaustive, and is not limited to embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope of the described embodiments. The selection of the terms used herein is intended to explain the principles of the embodiments, the practical application or technical improvements in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Examples

Embodiment Construction

[0017]Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0018]As used herein, the term "including" and its variants mean open-ended inclusion, i.e., "including but not limited to." The term "or" means "and / or" unless specifically stated otherwise. The term "based on" means "based at least in part on." The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment." The term "another embodiment" means "at least one further embodiment." The terms "first", "second", and the like...

Claims

1. A circuit breaker (100), the circuit breaker (100) comprising: a housing (10) provided with a first cavity (11) and an arc-extinguishing chamber (12) adjacent to each other inside the housing (10); a moving contact support (21) comprising a pivot connection part (211) and a rotating arm (212) extending from the pivot connection part (211), the pivot connection part (211) having a pivot axis, the rotating arm (212) being adapted to rotate in the first cavity (11), and an end of the rotating arm (212) being provided with a moving contact point (2121); a fixed contact (30) disposed on the housing (10), wherein a first end (301) of the fixed contact (30) is located outside the housing (10), a second end (302) of the fixed contact (30) extends through the first cavity (11) to a first side of the arc-extinguishing chamber (12), and the fixed contact (30) is provided with a fixed contact point (33) located in the first cavity (11); and an arc-extinguishing grid sheet assembly (40) disposed in the arc-extinguishing chamber (12) and comprising a first arc-extinguishing grid sheet (41) and a second arc-extinguishing grid sheet (42), the first arc-extinguishing grid sheet (41) corresponding to the first side of the arc-extinguishing chamber (12), and the second arc-extinguishing grid sheet (42) corresponding to a second side of the arc-extinguishing chamber (12), and wherein the arc-extinguishing chamber (12) extends in an arcuate shape, and a distance (L) between a side surface (121) of the arc-extinguishing chamber (12) facing towards the pivot axis and the pivot axis gradually increases in a direction from the first side to the second side of the arc-extinguishing chamber (12).

2. The circuit breaker (100) of claim 1, wherein the housing (10) is provided with an exhaust port (101a, 101b), and the housing (10) is provided with a second cavity (13) inside the housing (10), wherein the second cavity (13) is located at a side of the arc-extinguishing chamber (12) away from the first cavity (11) and is in communication with the exhaust port (101a, 101b).

3. The circuit breaker (100) of claim 2, wherein: an arc guide channel (34) is disposed at the second end (302) of the fixed contact (30) and extends from the first side of the arc-extinguishing chamber (12) to a first side (131) of the second cavity (13), and a gap (35) is formed between the second end (302) of the fixed contact (30) and the first arc-extinguishing grid sheet (41) and between the arc guide channel (34) and the first arc-extinguishing grid sheet (41).

4. The circuit breaker (100) of claim 3, wherein the arc guide channel (34) comprises a first arc guide surface (341), a portion of the fixed contact (30) located in the arc-extinguishing chamber (12) comprises a second arc guide surface (322), wherein the second arc guide surface (322) is connected to the first arc guide surface (341), and the second arc guide surface (322) and the first arc guide surface (341) are aligned with each other at a joint therebetween.

5. The circuit breaker (100) of claim 4, wherein: the fixed contact (30) includes a main body (31) and an arc guide protrusion (32) protruding from the main body (31) to the first cavity (11) and the arc-extinguishing chamber (12), and the second arc guide surface (322) is located on the arc guide protrusion (32), and the arc guide protrusion (32) includes a third arc guide surface (323) extending from the second arc guide surface (322) to a side wall of the fixed contact point (33).

6. The circuit breaker (100) of any of claims 2 to 5, wherein a width (W1) of the first cavity (11) is less than a width (W2) of the arc-extinguishing chamber (12).

7. The circuit breaker (100) of any of claims 2 to 6, wherein: a first side (131) of the second cavity (13) is adjacent to the first side of the arc-extinguishing chamber (12), a second side (132) of the second cavity (13) is adjacent to the second side of the arc-extinguishing chamber (12), and the exhaust port (101) is located downstream of the second side of the second cavity (13), and a space of the second cavity (13) gradually increases in a direction from the first side (131) to the second side (132) of the second cavity (13).

8. The circuit breaker (100) of claim 7, wherein the housing (10) is provided with an exhaust passage (14a, 14b) inside, the second side (132) of the second chamber (13) is in communication with a first end of the exhaust passage (14a, 14b) through a curved passage, and a second end of the exhaust passage (14a, 14b) is in communication with the exhaust port (101a, 101b).

9. The circuit breaker (100) of claim 8, wherein: the housing (10) is provided with a mounting cavity (15), two first cavities (11), two arc-extinguishing chambers (12), two second cavities (13), and two exhaust passages (14a, 14b) inside the housing (10), and the housing (10) is provided with two exhaust ports (101a, 101b), wherein the two first cavities (11), the two arc-extinguishing chambers (12), and the two second cavities (13) are located at two sides of the mounting cavity (15), each second cavity (13) is in communication with the corresponding exhaust port (101a, 101b) through the corresponding exhaust passage (14a, 14b), and the two exhaust ports (101a, 101b) are located at a same side of the housing (10) and have a same opening direction; the moving contact support (21) comprises two rotating arms (212) extending from the pivot connection part (211) in opposite directions, the pivot connection part (211) is located in the mounting cavity (15), each rotating arm (212) is adapted to rotate in the corresponding first cavity (11), and the end of each rotating arm (212) is provided with the moving contact point (2121); the second end of each fixed contact (30) of two fixed contacts (30) passes through the corresponding first cavity (11) to the first side of the corresponding arc-extinguishing chamber (12), and each fixed contact (30) is provided with the fixed contact point (33); and two arc-extinguishing grid sheet assemblies (40) are provided in the two arc-extinguishing chambers (12).

10. The circuit breaker (100) of any of claims 2 to 9, comprising: an arc guide sheet (50), a first end of the arc guide sheet (50) being located at the second side of the arc-extinguishing chamber (12) and being adjacent to the second arc-extinguishing grid sheet (42), and a second end of the arc guide sheet (50) extending to a maximum opening position of the end of the rotating arm (212) in the first cavity (11); and gas-generating sheets arranged at two sides of the rotating arm (212).

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