circuit breaker

Abstract

The disclosure relates to a circuit breaker, comprising: a main contact pair comprising a main movable contact and a main stationary contact; a normally closed contact pair comprising an additional movable contact (10) and an additional stationary contact (20); wherein the normally closed contact pair is arranged in series with the main contact pair, and the normally closed contact pair is disconnected earlier than the main contact pair during a short circuit.

Description

Technical Field

[0001] This disclosure relates to a circuit breaker. Background Technology

[0002] Circuit breakers are important protective devices in power systems and are widely used in power systems and industrial automation. They can quickly cut off the current when a circuit abnormality occurs, such as overload or short circuit, to protect the circuit and equipment from damage.

[0003] Residential and commercial buildings, as well as some small industrial sites, require circuit breakers to have a small size. However, when space is limited, it is difficult for miniature circuit breakers to achieve high breaking capacity, such as more than 25kA.

[0004] Currently, large molded case circuit breakers (MCCBs) are generally used for scenarios with high breaking capacity requirements. However, due to the cost and size limitations of MCCBs, it is difficult to meet new market demands. Summary of the Invention

[0005] In response to the problems and needs mentioned above, this disclosure proposes a circuit breaker that solves the aforementioned problems and brings other technical benefits by adopting the following technical features.

[0006] This disclosure discloses a circuit breaker, comprising: a main contact pair, including a moving contact and a stationary contact; and a normally closed contact pair, including an additional moving contact and an additional stationary contact. The normally closed contact pair is connected in series with the main contact pair, and during a short circuit, the normally closed contact opens before the main contact pair.

[0007] According to a preferred embodiment, the additional stationary contact includes a stationary contact body portion having a first contact point, and the additional moving contact includes a moving contact body portion having a second contact point for cooperating with the first contact point, wherein the stationary contact body portion and the moving contact body portion are set at an acute angle.

[0008] According to a preferred embodiment, the circuit breaker further includes a magnetic ring arranged around an additional moving contact and an additional stationary contact.

[0009] According to a preferred embodiment, the magnetic ring includes a first segment located on both sides of the first contact and the second contact, and a second segment located on both sides of the moving contact body.

[0010] According to the preferred embodiment, the width of the second segment is greater than the width of the first segment.

[0011] According to a preferred embodiment, the second segment has an inclined edge parallel to the moving contact body.

[0012] According to a preferred embodiment, the circuit breaker further includes a support member surrounded by and supporting the magnetic ring, the support member being mounted to the additional stationary contact.

[0013] According to a preferred embodiment, the circuit breaker further includes a torsion spring, one end of which is connected to an additional moving contact, and the torsion spring is configured to provide a force to the additional moving contact to bias it from an open position toward a closed position.

[0014] According to a preferred embodiment, the additional moving contact includes a rotating base and a protrusion extending from the rotating base, with one end of the torsion spring fixed to the protrusion.

[0015] According to a preferred embodiment, the circuit breaker further includes an arc-extinguishing chamber located near the additional moving contact and the additional stationary contact to extinguish the electric arc generated between the additional moving contact and the additional stationary contact.

[0016] According to a preferred embodiment, the normally closed contact pair and the main contact pair are housed within the same circuit breaker housing.

[0017] The preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings so that the features and advantages of the present disclosure can be readily understood. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments of this disclosure will be briefly described below. The drawings are merely illustrative of some embodiments of this disclosure and are not intended to limit all embodiments of this disclosure to them.

[0019] Figure 1 An overall view of a circuit breaker according to a specific embodiment of the present disclosure is shown;

[0020] Figure 2 An overall view of a circuit breaker current limiting assembly according to a specific embodiment of the present disclosure is shown;

[0021] Figure 3 and Figure 4 The additional contact pair and magnetic ring assembly are shown in different views;

[0022] Figure 5 A partial view of a circuit breaker current limiting assembly according to a specific embodiment of the present disclosure is shown;

[0023] Figure 6 The locations of the additional contact pairs and the arc-extinguishing chamber are shown.

[0024] List of reference numerals

[0025] Additional moving contact 10

[0026] Moving contact body 11

[0027] First contact point 12

[0028] Rotating base 13

[0029] 14 protrusions

[0030] Additional stationary contact 20

[0031] Static contact head body 21

[0032] Second contact point 22

[0033] Magnetic ring assembly 30

[0034] Magnetic ring 31

[0035] Support component 32

[0036] Part 1, Section 33

[0037] Part Two, Section 34

[0038] Slanted edge 35

[0039] Torsion spring 40

[0040] Arc-extinguishing chamber 50

[0041] Arc extinguishing plate 51

[0042] Circuit breaker housing 60 Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0044] Compared to the embodiments shown in the accompanying drawings, feasible embodiments within the scope of this disclosure may have fewer components, other components not shown in the drawings, different components, components arranged differently, or components with different connections, etc. Furthermore, two or more components in the drawings may be implemented in a single component, or a single component shown in the drawings may be implemented as multiple separate components.

[0045] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, “an” or “a” and similar terms do not necessarily indicate a quantity limitation. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships, which may change accordingly when the absolute position of the described object changes.

[0046] This disclosure relates to circuit breakers. Figure 1 A general view of a circuit breaker according to a specific embodiment of the present disclosure is shown. Figure 1 As shown, in general, a circuit breaker may include a circuit breaker body and a current-limiting component section outlined by a dashed line.

[0047] The main body of the circuit breaker includes a pair of main contacts as core components. The main contact pair includes a stationary contact and a moving contact that cooperates with the stationary contact. The moving contact and the stationary contact work together to control the connection and disconnection of the circuit. When connection or disconnection occurs, the stationary contact remains stationary, while the moving contact moves relative to the stationary contact. For example, the moving contact can rotate about its own axis of rotation to engage or disengage from the stationary contact, thereby connecting or disconnecting the circuit.

[0048] To improve the breaking capacity of the circuit breaker without significantly increasing its spatial dimensions, this disclosure adds a current-limiting component to the circuit breaker. The current-limiting component is preferably located above or below the main body of the circuit breaker, so that the width of the circuit breaker remains almost unchanged.

[0049] The main functional component of the current limiting assembly is a normally closed contact pair, which includes an additional moving contact 10 and an additional stationary contact 20. This disclosure proposes connecting the normally closed contact pair in series with the main contact pair of the circuit breaker. Under normal conditions, i.e., when no external force is applied or a short circuit occurs, the additional moving contact 10 and the additional stationary contact 20 are in a closed state. During a short circuit, the normally closed contact opens before the main contact pair. This design of the normally closed contact pair allows for limiting the peak short-circuit current of the entire circuit by increasing the arc voltage, without significantly increasing the circuit breaker's size. This achieves rapid disconnection and current limitation, reduces short-circuit energy, and protects the circuit.

[0050] Preferably, the circuit breaker body and the current-limiting assembly are housed within the same circuit breaker housing 60. In other words, the current-limiting assembly is not a separate structure relative to the circuit breaker, but rather a part of the circuit breaker. The normally closed contact pair and the main contact pair of the circuit breaker are housed within the same circuit breaker housing 60.

[0051] The following text combines Figures 2 to 6 This disclosure provides a detailed description of the circuit breakers proposed herein, particularly the specific features of the current-limiting components of the circuit breakers.

[0052] like Figure 2 As shown, the circuit breaker current limiting component preferably includes an additional contact pair consisting of an additional moving contact 10 and an additional stationary contact 20, a magnetic ring assembly 30 arranged around the additional contact pair, and an arc-extinguishing chamber 50 located near the additional contact pair.

[0053] The auxiliary stationary contact 20 is fixed in the circuit breaker, for example, fixed to the inner wall of the circuit breaker housing 60 or other support structure that is stationary relative to the circuit breaker housing 60. The auxiliary moving contact 10 is mounted to the circuit breaker in a manner that allows it to rotate between an open position and a closed position. When the auxiliary moving contact 10 is in the open position, the auxiliary contact pair is in the open state; when the auxiliary moving contact 10 is rotated to the closed position, the auxiliary contact pair is in the closed state.

[0054] Figure 6 The additional moving contact 10 and the additional stationary contact 20 are shown in the closed state. Preferably, as Figure 6 As shown, the additional stationary contact 20 includes a stationary contact body 21, which is provided with a first contact 12. The additional moving contact 10 includes a moving contact body 11, which is provided with a second contact 22 for cooperating with the first contact 12. When the additional moving contact 10 and the additional stationary contact 20 are closed, the first contact 12 and the second contact 22 are in contact, thereby conducting current. When the additional moving contact 10 and the additional stationary contact 20 are open, the first contact 12 and the second contact 22 are open, thereby cutting off the current.

[0055] Preferred options Figure 6 As shown, the stationary contact body 21 and the moving contact body 11 are set at an acute angle. Preferably, the angle between the stationary contact body 21 and the moving contact body 11 is less than 60°, and more preferably, the angle between the stationary contact body 21 and the moving contact body 11 is less than 50°, or less than 45°, or less than 40°.

[0056] By setting an acute angle between the stationary contact body 21 and the moving contact body 11, the paths through which the current flows through the stationary contact body 21 and the moving contact body 11 also have an acute angle. Thus, when the additional moving contact 10 and the additional stationary contact 20 are in contact, the currents flowing through the additional moving contact 10 and the additional stationary contact 20 are opposite. Figure 6 Taking the direction of current flow as an example, the current flow direction in the auxiliary stationary contact 20 may be from left to right, while the current flow direction in the auxiliary moving contact 10 is from right to left, thus creating an electro-repulsive force between the auxiliary moving contact 10 and the auxiliary stationary contact 20. When a short-circuit fault occurs, the current increases sharply, and the electro-repulsive force between the contacts also increases rapidly. This electro-repulsive force can quickly overcome the contact pressure between the contacts, allowing the auxiliary moving contact 10 and the auxiliary stationary contact 20 to separate quickly, improving the response speed and safety performance of the circuit breaker.

[0057] Preferably, the stationary contact body 21 has a generally straight structure. However, this disclosure does not limit the specific structure of the additional stationary contact 20. In addition to the stationary contact body 21 with the first contact point 12, the additional stationary contact 20 may also have a connection structure that is integrally connected to the stationary contact body 21 but at an angle.

[0058] Preferably, the moving contact body 11 has a generally flat structure. In addition to the moving contact body 11, the additional moving contact 10 may include a rotating base 13 from which the moving contact body 11 extends. The axis of rotation of the additional moving contact 10 extends through the rotating base 13. The rotating base 13 of the additional moving contact 10 may be provided with a through hole for rotatable mounting to a rotating shaft. Alternatively, the rotating base 13 may be provided with a rotating shaft fixed relative to the rotating base 13, the rotating shaft being rotatably mounted to the circuit breaker.

[0059] Preferably, the circuit breaker further includes a magnetic ring assembly 30 surrounding the additional moving contact 10 and the additional stationary contact 20, the magnetic ring assembly 30 including a magnetic ring 31. The magnetic ring 31 improves the opening speed of the moving contact, making it easier for the moving contact to open via electrodynamic repulsion during a short circuit, while also reducing the rebound speed. This limits the short-circuit current and reduces the risk of welding between the additional moving contact 10 and the additional stationary contact 20.

[0060] The specific structure of the magnetic ring 31 is not limited, but it is preferred to form a 360-degree rotating structure to surround the additional moving contact 10 and the additional stationary contact 20. The cross-section of the magnetic ring 31 may be circular, rectangular, polygonal or irregular in shape.

[0061] Preferably, such as Figure 3 and 4As shown, the magnetic ring 31 includes a first segment 33 located on both sides of the first contact 12 and the second contact 22, and a second segment 34 located on both sides of the moving contact body 11. In other words, the magnetic ring 31 surrounds not only the contact positions of the additional moving contact 10 and the additional stationary contact 20, but also the moving contact body 11. This design can further improve the opening speed of the moving contact, limit the short-circuit current, and reduce the risk of welding between the moving and stationary contacts. In addition, the magnetic ring 31 may also include additional segments located above the first segment 33 and below the second segment 34, which together with the first and second segments form a ring structure.

[0062] Preferably, the width of the second segment 34 is greater than the width of the first segment 33. Here, "width" can refer to the maximum or average width of the first segment 33 and the second segment 34. Figure 4 In the embodiments, example widths of the first segment 33 and the second segment 34 are shown as h1 and h2, respectively. By providing a smaller width for the first segment 33 surrounding the first contact 12 and the second contact 22, material savings can be achieved, while by providing a larger width for the second segment 34 surrounding the moving contact body 11, the effects of the magnetic ring 31 on improving the moving contact opening speed, limiting short-circuit current, and reducing the risk of welding can be fully realized.

[0063] like Figure 4 As shown, the second segment 34 of the magnetic ring 31 preferably has an inclined edge 35 parallel to the moving contact body 11. As previously mentioned, this disclosure preferably sets the stationary contact body 21 and the moving contact body 11 at an acute angle. By providing an inclined edge 35 parallel to the inclined moving contact body 11 to the second segment 34 of the magnetic ring 31, the effect of the magnetic ring 31 on the moving contact body can be further ensured while reducing material usage.

[0064] The magnetic ring assembly 30 also includes a support member 32 surrounded by the magnetic ring 31. The support member 32 is made of insulating material and serves both to support the magnetic ring 31 and as an insulating barrier between the magnetic ring 31 and the contacts. The specific structure of the support member 32 is not limited, but it is preferably formed in a 360-degree rotating structure to surround the additional moving contact 10 and the additional stationary contact 20. The cross-section of the support member 32 may be circular, rectangular, polygonal, or irregular in shape.

[0065] Preferably, the support member 32 is mounted to the additional stationary contact 20, for example, to the stationary contact body 21 of the additional stationary contact 20.

[0066] The circuit breaker disclosed herein preferably further includes a torsion spring 40, one end of which is connected to an additional moving contact 10, and the torsion spring 40 is configured to provide a force to the additional moving contact 10 to bias it from an open position toward a closed position. The force provided by the torsion spring 40 allows the additional moving contact 10 and the additional stationary contact 20 to be in a normally closed state.

[0067] The torsion spring 40 preferably has a helical elastic body, which may be made of metal wire. The torsion spring 40 is designed to store energy when subjected to torsion and return to its original shape when released, thereby generating a biasing force.

[0068] Preferably, such as Figures 2 to 5 As shown, the additional moving contact 10 includes a protrusion 14 extending from the rotating base 13, and one end of the torsion spring 40 is fixed to the protrusion 14. Providing the protrusion 14 on the additional moving contact 10 as a connection structure for the torsion spring 40 ensures that the torsion spring 40 can apply force stably, while allowing the additional moving contact 10 to move when needed.

[0069] By utilizing the restoring force of the torsion spring 40 and the protrusion 14 on the auxiliary moving contact 10, the auxiliary moving contact 10 can be automatically returned to the closed position in a timely manner after the circuit breaker operation. This design improves the reliability and safety of the circuit breaker through a simple structure.

[0070] According to a preferred embodiment of this disclosure, the circuit breaker further includes an arc-extinguishing chamber 50. The arc-extinguishing chamber 50 may be located near the additional moving contact 10 and the additional stationary contact 20, particularly near or downstream of the arc generated by the additional moving contact 10 and the additional stationary contact 20, to extinguish the arc generated between the additional moving contact 10 and the additional stationary contact 20.

[0071] The arc-extinguishing chamber 50 may have a plurality of arc-extinguishing plates 51, each of which has, for example, the same or substantially the same size and shape. Each arc-extinguishing plate 51 extends in the direction of arc travel, and the individual arc-extinguishing plates 51 are spaced apart from each other along the height direction of the arc-extinguishing chamber 50. The plurality of arc-extinguishing plates 51 are preferably spaced apart from each other at uniform intervals. This arrangement helps to disperse the arc energy, making it easier to extinguish. The arc-extinguishing chamber 50 may also include one or more insulating supports 32, such as insulating side plates, to hold the plurality of arc-extinguishing plates 51.

[0072] By incorporating the arc-extinguishing chamber 50, the circuit breaker can effectively manage the arc when the auxiliary moving contact 10 and the accessory stationary contact are disconnected, thereby improving the performance and safety of the circuit breaker.

[0073] The exemplary implementation of the solution proposed in this disclosure has been described in detail above with reference to preferred embodiments. However, those skilled in the art will understand that various modifications and alterations can be made to the above specific embodiments without departing from the spirit of this disclosure, and various combinations can be made to the various technical features and structures proposed in this disclosure without exceeding the protection scope of this disclosure, which is determined by the appended claims.

Claims

1. A circuit breaker, comprising: The main contact pair includes the driving contact and the main stationary contact; Normally closed contact pair, including additional moving contact (10) and additional stationary contact (20); The normally closed contact pair is connected in series with the main contact pair, and during a short circuit, the normally closed contact breaks first compared to the main contact pair.

2. The circuit breaker as claimed in claim 1, wherein, The additional stationary contact (20) includes a stationary contact body (21) with a first contact (12) and the additional moving contact (10) includes a moving contact body (11) with a second contact (22) for cooperating with the first contact (12). The stationary contact body (21) and the moving contact body (11) are set at an acute angle.

3. The circuit breaker as claimed in claim 2, wherein, The circuit breaker also includes a magnetic ring (31) arranged around an additional moving contact (10) and an additional stationary contact (20).

4. The circuit breaker as claimed in claim 3, wherein, The magnetic ring (31) includes a first section (33) located on both sides of the first contact (12) and the second contact (22) and a second section (34) located on both sides of the moving contact body (11).

5. The circuit breaker as claimed in claim 4, wherein, The width of the second segment (34) is greater than the width of the first segment (33).

6. The circuit breaker as claimed in claim 4, wherein, The second segment (34) has an inclined edge (35) parallel to the moving contact body (11).

7. The circuit breaker as claimed in claim 3, wherein, The circuit breaker also includes a support (32) surrounding and supporting the magnetic ring (31), the support (32) being mounted to the additional stationary contact (20).

8. The circuit breaker as claimed in claim 1, wherein, The circuit breaker also includes a torsion spring (40), one end of which is connected to an additional moving contact (10), and the torsion spring (40) is configured to provide a force to the additional moving contact (10) to bias it from an open position toward a closed position.

9. The circuit breaker as claimed in claim 8, wherein, The additional moving contact (10) includes a rotating base (13) and a protrusion (14) extending from the rotating base (13), one end of the torsion spring (40) being fixed to the protrusion (14).

10. The circuit breaker as claimed in claim 1, wherein, The circuit breaker also includes an arc-extinguishing chamber (50) located near the additional moving contact (10) and the additional stationary contact (20) to extinguish the arc generated between the additional moving contact (10) and the additional stationary contact (20).

11. The circuit breaker as claimed in claim 1, wherein, The normally closed contact pair and the main contact pair are housed in the same circuit breaker housing (60).

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