Vacuum interrupter, vacuum switch and shunt load switch
By using a stainless steel conductive rod and a vacuum interrupter designed without a shield, the problems of large size and high cost of vacuum interrupters have been solved, achieving miniaturization and improved insulation performance, and simplifying the manufacturing process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- EATON ELECTRIC INC
- Filing Date
- 2025-04-30
- Publication Date
- 2026-06-12
Smart Images
Figure CN224355188U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of switches, and particularly relates to a vacuum interrupter, a vacuum switch, and a parallel load switch. Background Technology
[0002] The statements in this section are merely to provide background information related to this utility model to aid in understanding it, and this background information does not necessarily constitute prior art.
[0003] Vacuum switches are switching devices that utilize vacuum as the arc-extinguishing and insulating medium. The vacuum interrupter, as the core component of a vacuum switch, is used to quickly extinguish the electric arc when the circuit is broken, preventing reignition or continuous discharge that could damage the equipment. Due to the widespread application of vacuum interrupters in medium and high voltage switchgear, technical personnel have been continuously dedicated to improving their performance. Utility Model Content
[0004] Therefore, the purpose of this utility model is to overcome the defects of the prior art and provide a vacuum interrupter, comprising: an insulating shell, a moving contact assembly, and a stationary contact assembly, wherein the moving contact assembly and the stationary contact assembly respectively pass through opposite ends of the insulating shell, the inner wall of the insulating shell has a first variable diameter portion and a second variable diameter portion, the first variable diameter portion and the second variable diameter portion dividing the insulating shell into a first region located in the middle, a second region adjacent to the stationary contact assembly, and a third region adjacent to the moving contact assembly, the moving contact assembly including a moving contact, the stationary contact assembly including a stationary contact, the moving contact and the stationary contact being disposed within the space defined by the first region, wherein the first variable diameter portion is a first protrusion protruding relative to the inner wall of the first region and the inner wall of the second region, and the second variable diameter portion is a second protrusion protruding relative to the inner wall of the third region, thereby enabling the metal vapor generated by the separation of the moving contact and the stationary contact to be confined within the space defined by the first region. This vacuum interrupter is particularly suitable for parallel load switches.
[0005] According to the vacuum interrupter of this utility model, preferably, the lateral limiting dimension of the first region is smaller than the lateral limiting dimension of the third region, and the second protrusion is a step portion at the boundary between the first region and the third region.
[0006] According to the vacuum interrupter of this utility model, preferably, the outer surfaces of the first region, the second region and the third region are flush, the first region has a first thickness and the third region has a thickness less than the first thickness.
[0007] According to the vacuum interrupter of this invention, preferably, the second region has a thickness less than the first thickness.
[0008] According to the vacuum interrupter of this invention, preferably, the outer surfaces of the first region, the second region, and the third region also have a corrugated structure.
[0009] According to the vacuum interrupter of this utility model, preferably, the moving contact and the stationary contact each include a first part and a second part protruding from the first part, wherein the lateral dimension of the first part is greater than the lateral dimension of the second part.
[0010] According to the vacuum interrupter of this utility model, preferably, the moving contact assembly further includes a moving conductive rod, the stationary contact assembly further includes a stationary conductive rod, the moving conductive rod and the moving contact respectively have matching mechanical connection parts, and the stationary conductive rod and the stationary contact respectively have matching mechanical connection parts.
[0011] According to the vacuum interrupter of this utility model, preferably, at least one of the moving conductive rod and the stationary conductive rod is a stainless steel conductive rod.
[0012] On the other hand, the present invention provides a vacuum switch, which includes the aforementioned vacuum interrupter according to the present invention.
[0013] In another aspect, this utility model provides a parallel load switch, which includes a vacuum switch and a rotary switch according to this utility model. The rotary switch includes a first terminal, a second terminal, a rotary drive conductive rod, and an arc-shaped contact. The rotary drive conductive rod is configured such that one end is electrically connected to the arc-shaped contact and enables the arc-shaped contact to move along an arc. The first terminal and the second terminal are arranged on the arc. The first output terminal of the vacuum switch is electrically connected to the first terminal, the second output terminal of the vacuum switch is electrically connected to the first terminal of the parallel load switch, the second terminal is electrically connected to the second terminal of the parallel load switch, and the other end of the rotary drive conductive rod is electrically connected to the third terminal of the parallel load switch.
[0014] Compared to existing technologies, the vacuum interrupter design of this invention eliminates the need for a metal shield, significantly reducing the size of the interrupter and improving insulation performance within a miniaturized insulating shell. The ceramic shell has a two-tiered stepped interior, thus eliminating the need for a metal shield. This structure is typically unsuitable for standard interrupters because a large amount of vapor is generated during current interruption, which can deposit on the ceramic shell and affect the overall insulation performance of the vacuum interrupter. However, this structure is feasible in vacuum interrupters used for small load switches, where the interrupting current is low and only a limited number of electrical operations are required. The specially designed contact shape also helps prevent metal vapor from depositing on the entire inner surface of the ceramic, thus preserving its insulation performance. Furthermore, to minimize metal vapor contamination of the inner surface of the ceramic shell, a specially shaped contact with steps is designed to control the diffusion direction of the metal vapor. Attached Figure Description
[0015] The embodiments of this utility model will be further described below with reference to the accompanying drawings, wherein:
[0016] Figure 1 This is a schematic diagram of the longitudinal cross-sectional structure of a vacuum interrupter according to an embodiment of the present invention;
[0017] Figure 2 This is a perspective view of a vacuum interrupter according to an embodiment of the present invention;
[0018] Figure 3 for Figure 2 A magnified view of a portion;
[0019] Figure 4 A schematic diagram of the structure of a parallel load switch according to an embodiment of the present invention; and
[0020] Figure 5 This is a schematic diagram illustrating the disconnection process of a parallel load switch according to an embodiment of the present invention. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.
[0022] The inventors discovered that current mainstream research and development of vacuum interrupters focuses on improving their breaking capacity for large currents (such as 630A~6300A) to meet the short-circuit fault protection requirements of power systems. Under this technological guidance, engineers primarily focus on improving the electrical performance of vacuum interrupters (such as insulation strength, breaking capacity, and current-carrying capacity), resulting in higher costs and larger sizes for vacuum interrupters.
[0023] One of the core design principles for the electrodes (conductive rods) of a vacuum interrupter is low contact resistance. Currently, there is a consensus among engineers in the switchgear field that copper-based materials (pure copper or copper alloys) are the ideal choice for electrodes because the copper substrate ensures low contact resistance and reduces temperature rise.
[0024] Stainless steel is a corrosion-resistant alloy steel made with iron (Fe) as the base material and the addition of chromium (Cr≥10.5%) and alloying elements such as nickel (Ni), molybdenum (Mo), and nitrogen (N). Stainless steel possesses excellent corrosion resistance and mechanical strength; however, its electrical conductivity is significantly lower than that of metals such as copper (its resistivity is approximately 40 times that of pure copper), its resistance to arc erosion is weak, and it is prone to softening or intergranular corrosion at high temperatures. For a long time, stainless steel has not been a mainstream choice in the field of conductive materials, with its technological advantages focusing more on structural functions than electrical properties. In particular, due to the poor electrical conductivity of stainless steel, industry professionals have never considered using it to make electrodes for vacuum interrupters.
[0025] The inventors of this invention have overcome technical biases and creatively proposed a vacuum interrupter with stainless steel electrodes. This vacuum interrupter is connected in parallel to the main circuit in application and is therefore also called a shunt vacuum interrupter. This vacuum interrupter is in a non-current-carrying state in most application scenarios (including when the main circuit is operating normally and when the main circuit is disconnected), and only experiences a brief overcurrent during the main circuit disconnection process. The inventors recognized that due to this short-term overcurrent, the high resistance of the stainless steel electrodes does not cause a significant temperature rise. On the other hand, because of the high mechanical strength of stainless steel, smaller electrodes can meet the strength requirements, allowing for a significant reduction in the volume of the vacuum interrupter and also a marked decrease in its cost.
[0026] According to some embodiments of this utility model, a vacuum interrupter is provided, see [link to relevant documentation]. Figure 1The diagram shows a longitudinal cross-sectional view of the vacuum interrupter 100 of this embodiment. The vacuum interrupter of this embodiment includes an insulating shell 102 and moving contact assemblies and stationary contact assemblies passing through opposite ends of the insulating shell 102. The moving contact assembly includes a moving conductive rod 104 passing through a first end (e.g., its first through-hole 1021) of the insulating shell 102 and a moving contact 105 disposed at one end of the moving conductive rod 104. The stationary contact assembly includes a stationary conductive rod 106 passing through a second end (e.g., its second through-hole 1022) of the insulating shell 102 opposite to the first end and a stationary contact 107 disposed at one end of the stationary conductive rod 106. Circuit connection and disconnection are achieved by the closing and opening of the moving contact 105 and the stationary contact 107. In this embodiment of the invention, at least one of the moving conductive rod 104 and the stationary conductive rod 106 is a stainless steel conductive rod, particularly a cold-stamped stainless steel conductive rod. Stainless steel conductive rods have high mechanical strength and therefore can be adapted to smaller dimensions. The diameter of the stainless steel conductive rod of this invention is approximately one-third the diameter of a conventional copper conductive rod. In embodiments of this invention, the diameter of the stainless steel conductive rod does not exceed 15 mm.
[0027] Furthermore, in order to achieve dynamic sealing of the vacuum interrupter, that is, to maintain the vacuum seal of the interrupter during the movement of the moving contact, the moving contact assembly also includes a tubular elastic element sleeved on the outside of the moving conductive rod 104, see [link to relevant documentation]. Figure 1 The tubular elastic element is preferably a bellows 108. A bellows is a metal tube with a corrugated shape, typically made of stainless steel. Preferably, one end of the bellows 108 is fixed to the insulating shell 102 by welding or mechanical connection and is in close contact with the first through hole 1021, while the other end is fixedly connected to the moving conductive rod 104. The corrugated structure of the bellows allows it to elastically expand and contract in the axial direction, thereby allowing the moving conductive rod 104 to move freely within a certain range, meeting the operational requirements of the arc-extinguishing chamber. When the moving conductive rod 104 moves, the bellows 108 will expand and contract accordingly, but its corrugated structure allows it to maintain a tight seal.
[0028] In another embodiment, preferably, such as Figure 1 and Figure 2 As shown, Figure 2This is a perspective view of a vacuum interrupter according to an embodiment of the present invention. The moving contact assembly further includes a bushing 109 disposed between the moving conductive rod 104 and the bellows 108. The bushing 109 matches the shape of the moving conductive rod 104 and acts as a "mechanical buffer" between the moving conductive rod 104 and the bellows 108. Specifically, the moving conductive rod may rub against the inner wall of the bellows during movement. The bushing can reduce this direct contact, thereby reducing the wear of the bellows and extending its service life. In particular, when the surface of the moving conductive rod has burrs or unevenness, the bushing can prevent the moving conductive rod from scratching the inner wall of the bellows during movement. The bushing can also provide additional support for the moving conductive rod, reducing the swaying and vibration of the moving conductive rod during movement, thereby improving the mechanical stability of the system. The bushing can ensure the concentricity of the moving conductive rod and the bellows, reducing stress concentration caused by eccentric movement and further improving the reliability of the system. In summary, bushings, through mechanisms such as motion guidance, wear isolation, and stress dispersion, can improve the operational reliability of the arc-extinguishing chamber and are one of the key technologies for the long-life design of vacuum switchgear.
[0029] In a preferred embodiment of this utility model, see [link to relevant documentation]. Figure 2 as well as Figure 3 shown Figure 2 In the enlarged view of the circular area, the portion of the movable conductive rod 104 that contacts the bushing 109 is hexagonal prism-shaped, and correspondingly, the bushing 109 is also hexagonal prism-shaped. The edges of the hexagonal prism naturally form positioning and limiting portions, facilitating the matching connection and fixation of the movable conductive rod 104 and the bushing 109. Furthermore, the portion of the movable conductive rod 104 that does not contact the bushing 109 can be configured into any desired shape. For example, to achieve connection with external components of the arc-extinguishing chamber, the corresponding portion of the movable conductive rod 104 can be configured as a threaded shape. Those skilled in the art will understand that the portion of the movable conductive rod 104 that contacts the bushing 109 is not limited to a hexagonal prism shape; any shape with edges can achieve positioning and limiting with the bushing 109, such as a triangular prism, a square prism, a pentagonal prism, a heptagonal prism, an octagonal prism, etc.
[0030] In embodiments of this utility model, preferably, the insulating shell 102 is a ceramic shell, and more preferably a pre-formed ceramic shell. For example... Figure 1 and 2 As shown, the outer wall of the insulating shell 102 has a corrugated surface. However, in embodiments of this invention, the shape of the outer wall of the ceramic shell is not limited, and it can have any other surface shape, including a planar surface.
[0031] In vacuum interrupters, when the arc is extinguished within the chamber, the contact material (e.g., copper or its alloys) evaporates due to the high temperature, forming metal vapor. This metal vapor may deposit on the inner wall of the insulating shell of the interrupter, leading to a decrease in the insulation performance of the shell. The inventors have also discovered that currently, to overcome the influence of metal vapor on the insulation performance of the insulating shell, a metal shield is typically used to adsorb the metal vapor and form a condensate, preventing the metal vapor from contaminating the surface of the insulating shell and thus maintaining its insulation performance.
[0032] The inventors have also creatively adopted an unshielded design, using a special design of the inner wall of the insulating shell to restrict metal vapor and reduce the impact of metal vapor on the insulating shell.
[0033] In some embodiments of this utility model, such as Figure 1 As shown, the inner wall of the insulating housing 102 has a first variable diameter portion 1023 and a second variable diameter portion 1024. The moving contact 105 and the stationary contact 107 are disposed in the region between the first variable diameter portion 1023 and the second variable diameter portion 1024, and the range of motion of the moving contact 105 is also within this region. The first variable diameter portion 1023 and the second variable diameter portion 1024 divide the insulating housing 102 into a first region A accommodating the moving contact 105 and the stationary contact 107, a second region B accommodating at least a portion of the stationary conductive rod 106, and a third region C accommodating at least a portion of the moving conductive rod 104, the bellows 108, and the bushing 109. In some embodiments, the first, second, and third regions have the same thickness. In other embodiments, the outer surfaces of the three regions of the insulating housing 102 are flush, the first region A and the second region B have the same thickness d1, and the third region C has a thickness d2 less than d1, thereby providing a larger internal space in the third region compared to the other two regions. In other embodiments, the outer surfaces of the three regions of the insulating housing 102 are flush, and the thicknesses of the second region B and the third region C are both less than the thickness of the first region A. Optionally, a protruding corrugated structure for increasing the external insulation distance is also provided on the outer surface of the insulating housing 102. In some embodiments, the thickness d2 is 80%-95% of the thickness d1. Compared with the prior art design where the wall thickness of the middle region is only half that of the two sides, this embodiment significantly improves the arc resistance and thermal stability of the contact region by optimizing the wall thickness distribution. At the same time, by reasonably reducing the wall thickness of non-critical regions, it avoids material waste and creates more space for the installation of complex internal components, achieving a balanced optimization of reliability, compactness, and cost-effectiveness.
[0034] When the moving and stationary contacts 105 and 107 separate, an electric arc is generated. When the arc is extinguished in the arc-extinguishing chamber, the metal vapor formed by the contact material may deposit on the inner wall of the insulating shell 102 of the arc-extinguishing chamber, causing a decrease in the insulation performance of the insulating shell 102. The first variable diameter portion 1023 and the second variable diameter portion 1024 of this invention can prevent the metal vapor from diffusing to the external area, that is, confine the metal vapor to the area between the first variable diameter portion 1023 and the second variable diameter portion 1024 without affecting other areas. In this way, only a small part of the ceramic shell 102 will deposit metal vapor, which will not have a significant impact on its overall insulation performance. Based on the ingenious design of this invention, a special shielding cover can be omitted, simplifying the manufacturing process and saving costs.
[0035] In a preferred embodiment of this invention, the first variable diameter portion 1023 is a first protrusion protruding relative to the inner wall of the first region A and the inner wall of the second region B. The larger the size of the first protrusion, the better the effect of preventing metal vapor from entering the second region B. However, considering the smooth insertion of the stationary contact during the assembly of the vacuum interrupter, the internal area restricted by the first protrusion should at least allow the stationary contact to pass through. Preferably, the first protrusion is an annular protrusion, and the inner diameter of the annular protrusion needs to be at least greater than the outer diameter of the stationary contact. In some embodiments, the second variable diameter portion is a second protrusion protruding relative to the inner wall of the third region C. In some embodiments, the second variable diameter portion is a second protrusion protruding relative to both the inner wall of the first region A and the inner wall of the third region C. The larger the size of the second protrusion, the better the effect of preventing metal vapor from entering the third region C. Similarly, considering the smooth insertion of the moving contact during the assembly of the vacuum interrupter, the internal area restricted by the second protrusion should at least allow the moving contact to pass through. Preferably, the second protrusion is also an annular protrusion, and the inner diameter of the annular protrusion needs to be at least greater than the outer diameter of the moving contact.
[0036] In some embodiments of this utility model, such as Figure 1 As shown, the second diameter-changing portion 1024 is located near the bellows 109, and the lateral dimension of the bellows 109 is much larger than that of the moving conductive rod 104, and its lateral dimension increases during the compression of the bellows 109. Therefore, when the second diameter-changing portion 1024 is configured as a second protrusion, considering that the second protrusion does not affect the expansion and contraction of the bellows 109, the inner edge of the second protrusion must be a certain distance away from the outer edge of the bellows. This requires increasing the lateral dimension of the insulating shell, which also increases the volume of the vacuum interrupter, hindering the miniaturization of the vacuum interrupter.
[0037] The inventors also discovered that the metal vapor generated during the separation of the moving and stationary contacts travels in a basically straight line. When the metal vapor encounters the inner wall region closest to the insulating shell, most of it condenses in that region, while a small portion travels in a straight line along that inner wall due to the obstruction of the inner wall (e.g., Figure 1 (Moves upwards or downwards). The inventor creatively conceived of setting the second diameter-changing section 1024 as a stepped section (e.g., ...). Figure 1 As shown), the stepped portion is formed by the difference in inner diameter between the first region A and the third region C of the insulating shell on both sides. Figure 1 As shown, the first protrusion 1023 is arranged at the boundary between the first region A and the second region B. The lateral defining dimension of the first region A (meaning the cross-sectional dimension of the vacuum interrupter internal space defined by the first region A, preferably its cross-sectional diameter) is smaller than the lateral defining dimension of the third region C (meaning the cross-sectional dimension of the vacuum interrupter internal space defined by the third region C, preferably its cross-sectional diameter), thereby forming a step at the boundary between the first region A and the third region C. Since the lateral defining dimension of the first region A is smaller than the lateral defining dimension of the third region C, and the third region C is laterally outside the first inner wall region A, when metal vapor moves from the first region A to the third region C due to the obstruction of the first region A, the linearly moving metal vapor cannot contact the third region C, and therefore will not condense in the third region C. More preferably, the lateral defining dimension of the first region A is also smaller than the lateral defining dimension of the second region B, thereby further reducing the risk of metal vapor that may bypass the first protrusion 1023 condensing in the second region B. In a preferred embodiment, the lateral dimension of the first region A is at least 5% smaller than the lateral dimensions of the second region B and the third region C, preferably 5% to 20% smaller.
[0038] In a further preferred embodiment, such as Figure 1 As shown, the moving contact 105 and the stationary contact 107 are specifically designed in a stepped shape, each comprising a first portion connected to the corresponding conductive rod and a second portion protruding from the first portion. The lateral dimension of the first portion is larger than that of the second portion, thereby forming a stepped portion between the first and second portions. Preferably, the first and second portions have arc-shaped chamfers. Preferably, the lateral dimension of the first portion is at least 10% larger than that of the second portion, preferably 10% to 20% larger. When the moving contact 105 and the stationary contact 107 separate, an electric arc is formed between the second portions of the moving contact and the stationary contact. The generated metal vapor is blocked and guided by the stepped portion, further reducing the metal vapor reaching the second and third inner wall regions. In another embodiment of this invention, only one of the moving and stationary contacts is designed in a stepped shape.
[0039] In a further preferred embodiment of this invention, the connection between the contact and the conductive rod employs a dual connection method combining mechanical and metallurgical connections. Mechanical connections include bolts, rivets, clips, key connections, etc. Metallurgical connections, also known as material connections, include various welding processes, such as fusion welding, pressure welding, and brazing. Currently, the contact and conductive rod are typically connected only by welding; therefore, the manufacturing process of a vacuum interrupter involves two welding processes: one is the welding of the contact and the conductive rod, and the other is the welding between all components of the vacuum interrupter, including the contact assembly. However, in the manufacturing process of the vacuum interrupter of this invention, the contact and the conductive rod are first mechanically connected to form a contact pre-assembly. Then, the contact pre-assembly is installed in the housing, and then a unified welding process is performed. This welding step not only achieves welding between the contact and the conductive rod but also welding between the components of the vacuum interrupter. In summary, the contacts and conductive rods of the vacuum interrupter of this invention each have matching mechanical connection parts. The mechanical connection of these parts saves welding steps in the manufacturing process of the vacuum interrupter, thereby reducing manufacturing costs.
[0040] In such Figure 1 In the example shown, the moving contact 105 and the moving conductive rod 104 are respectively provided with matching riveting portions, and the stationary contact 107 and the stationary conductive rod 106 are respectively provided with matching riveting portions. When riveting the moving / stationary contacts and the moving / stationary conductive rods together through the riveting portions, solder is inserted into the contact area beforehand. Then, the moving / stationary contact assembly is installed onto the insulating housing 102 for subsequent overall brazing operations.
[0041] In one embodiment of this utility model, the insulating shell 102 is a one-piece molded ceramic shell, which has a simple structure and eliminates the risk of end cap leakage. In another embodiment, the insulating shell 102 includes a first end cap 1025 and a second end cap 1026 disposed opposite to each other. A first through hole 1021 is disposed in the first end cap 1025, and a second through hole 1022 is disposed in the second end cap 1026. The end cap design improves the sealing reliability and insulation safety of the insulating shell 102.
[0042] An embodiment of this utility model also provides a vacuum switch, which includes the aforementioned vacuum interrupter according to this utility model, and further includes a first lead-out end and a second lead-out end connected to a moving conductive rod and a stationary conductive rod respectively connected to the vacuum interrupter, as well as an operating mechanism for driving the moving conductive rod, such as an insulating pull rod. The vacuum interrupter of this utility model is applicable to any vacuum switch known in the art. The specific structure of the vacuum switch will not be described in detail here.
[0043] An embodiment of this utility model also provides a parallel load switch, see [link to relevant documentation]. Figure 4The schematic diagram of the parallel load switch of this embodiment shows that it includes a vacuum switch 401 and a rotary switch 402 according to the aforementioned embodiment. The rotary switch 402 includes a first terminal a, a second terminal b, a rotary drive conductive rod 403, and an arc-shaped contact 404 fixedly connected to one end of the rotary drive conductive rod 403. The rotary drive conductive rod 403 is rotatable about a rotation center o, thereby causing the arc-shaped contact 404 to move along an arc centered at the rotation center o. The first terminal a and the second terminal b are disposed on the arc. The rotation center o (i.e., the other end of the rotary drive conductive rod 403) can also serve as a third terminal of the rotary switch 402. The first output terminal of vacuum switch 401 is electrically connected to the first terminal a of rotary switch 402; the second output terminal of vacuum switch 401 is used as (or electrically connected to) the first terminal T1 of parallel load switch; the second terminal b of rotary switch 402 is used as (or electrically connected to) the second terminal T2 of parallel load switch; and the third terminal of rotary switch 402 is used as (or electrically connected to) the third terminal T3 of parallel load switch. Figure 5 The schematic diagram shown is of the disconnection process of the parallel load switch according to an embodiment of the present invention, where BUS represents the main circuit bus. When the rotating drive conductive rod 403 drives the arc-shaped contact 404 to move along the arc, the following conduction / disconnection modes can be achieved:
[0044] When the arc-shaped contact 404 is electrically isolated from the first terminal a and electrically connected to the second terminal b, the circuit between the second terminal T2 and the third terminal T3 is connected, and the circuit between the first terminal T1 and the third terminal T3 is disconnected (corresponding to...). Figure 5 (the state shown in (a));
[0045] When the arc-shaped contact 404 is electrically connected to both the first terminal a and the second terminal b, the first terminal T1 and the second terminal T2 are electrically connected in parallel to the third terminal T3 (corresponding to...). Figure 5 (as shown in state (b)).
[0046] When the arc-shaped contact 404 is electrically connected to the first terminal a and electrically isolated from the second terminal b, the circuit between the first terminal T1 and the third terminal T3 is connected, and the circuit between the second terminal T2 and the third terminal T3 is disconnected (corresponding to...). Figure 5 The states shown in (c) and (d); and
[0047] When the arc-shaped contact 404 is electrically isolated from both the first terminal a and the second terminal b, the circuit between the first terminal T1, the second terminal T2, and the third terminal T3 is broken (corresponding to...). Figure 5 The states shown in (e) and (f).
[0048] like Figure 5 As shown, in the use of parallel load switches, the first terminal T1, the second terminal T2, and the third terminal T3 are all connected to the main circuit. Under normal circumstances, as... Figure 5 As shown in (a), the first terminal T1 and the third terminal T3 remain disconnected, while the second terminal T2 and the third terminal T3 remain connected. When the parallel load switch receives a disconnection command, the rotary drive conductive rod 403 rotates counterclockwise, driving the arc-shaped contact 404 to move counterclockwise along the arc. Figure 5 As shown in (b), the arc-shaped contact 404 is electrically connected to both the first terminal a and the second terminal b, and the main circuit current is shunt by the vacuum switch branch. Next, the arc-shaped contact 404 continues to move and is electrically isolated from the second terminal b, and the main circuit current flows through the vacuum switch branch from the first terminal T1 to the third terminal T3, as shown in (b). Figure 5 As shown in (c) and (d). From Figure 5 (c) to Figure 5 In stage (d), the vacuum switch 401 separates the moving and stationary contacts, disconnecting the vacuum switch branch and thus breaking the main circuit. Next, the rotary drive conductive rod 403 continues to rotate, as... Figure 5 As shown in (e), the arc-shaped contact 404 is floating. In this case, the moving and stationary contacts of the vacuum switch 401 can be closed or separated; as... Figure 5 As shown in (f), the arc-shaped contact 404 is electrically connected to the grounding terminal, the main circuit load is grounded, and the entire disconnection process of the parallel load switch is completed.
[0049] It can be seen that during the disconnection process of the parallel load switch, the vacuum interrupter only operates when... Figure 5 During the process from (b) to (d), current flows through, and the current-carrying time is very short. Typically, the current-carrying time of a vacuum interrupter is less than 100 milliseconds, and the breaking time is tens of milliseconds. Furthermore, during the current-carrying process, there is a period during which the main circuit current is shunted rather than fully carried; therefore, the load current of the vacuum interrupter is also relatively small. The aforementioned shunting vacuum interrupter of this invention is particularly suitable for applications with small load currents and short current-carrying times, because such small load currents and short current-carrying times will not cause excessive temperature rise in the stainless steel conductive rod.
[0050] The conduction process of the parallel load switch in this embodiment is the opposite of the aforementioned disconnection process. The rotating drive conductive rod 403 drives the arc-shaped contact 404 to rotate clockwise from the grounded state, and finally reaches the state where it is only electrically connected to the second terminal b. This will not be described in detail here.
[0051] This invention's vacuum interrupter uses a stainless steel conductive rod, which reduces the rod's diameter to below 15mm, thereby reducing the diameter of the vacuum interrupter's insulating shell to below 80mm, achieving a compact vacuum interrupter. This invention also eliminates the need for a dedicated shielding assembly, saving costs. Furthermore, the contacts and conductive rod of this invention employ a dual connection method combining mechanical and metallurgical connections, reducing manufacturing complexity and cost.
[0052] The parallel load switch of this utility model adopts the vacuum interrupter of this utility model, which is small in size, low in cost and simple in manufacturing process.
[0053] Although the present invention has been described through preferred embodiments, the present invention is not limited to the embodiments described herein, and includes various changes and variations without departing from the scope of the present invention.
Claims
1. A vacuum interrupter, characterized in that, The device includes an insulating housing, a moving contact assembly, and a stationary contact assembly, wherein the moving contact assembly and the stationary contact assembly pass through opposite ends of the insulating housing. The inner wall of the insulating housing has a first variable diameter portion and a second variable diameter portion, which divide the insulating housing into a first region located in the middle, a second region adjacent to the stationary contact assembly, and a third region adjacent to the moving contact assembly. The moving contact assembly includes a moving contact, and the stationary contact assembly includes a stationary contact. The moving contact and the stationary contact are disposed within the space defined by the first region. The first variable diameter portion is a first protrusion protruding relative to the inner wall of the first region and the inner wall of the second region, and the second variable diameter portion is a second protrusion protruding relative to the inner wall of the third region, thereby enabling the metal vapor generated by the separation of the moving contact and the stationary contact to be confined within the space defined by the first region.
2. The vacuum interrupter according to claim 1, characterized in that, The lateral defining dimension of the first region is smaller than that of the third region, and the second protrusion is a step portion at the boundary between the first region and the third region.
3. The vacuum interrupter according to claim 1, characterized in that, The outer surfaces of the first region, the second region, and the third region are flush, the first region has a first thickness, and the third region has a thickness less than the first thickness.
4. The vacuum interrupter according to claim 3, characterized in that, The second region has a thickness less than the first region.
5. The vacuum interrupter according to claim 3 or 4, characterized in that, The outer surfaces of the first region, the second region, and the third region also have a corrugated structure.
6. The vacuum interrupter according to claim 1, characterized in that, The moving contact and the stationary contact each include a first part and a second part protruding from the first part, wherein the lateral dimension of the first part is greater than the lateral dimension of the second part.
7. The vacuum interrupter according to claim 1, characterized in that, The moving contact assembly further includes a moving conductive rod, and the stationary contact assembly further includes a stationary conductive rod. The moving conductive rod and the moving contact each have a matching mechanical connection portion, and the stationary conductive rod and the stationary contact each have a matching mechanical connection portion.
8. The vacuum interrupter according to claim 7, characterized in that, At least one of the moving conductive rod and the stationary conductive rod is a stainless steel conductive rod.
9. A vacuum switch, characterized in that, Includes a vacuum interrupter according to any one of claims 1 to 8.
10. A parallel load switch, characterized in that, The invention includes a vacuum switch and a rotary switch according to claim 9, wherein the rotary switch includes a first terminal, a second terminal, a rotary drive conductive rod, and an arc-shaped contact, the rotary drive conductive rod being configured such that one end is electrically connected to the arc-shaped contact and enables the arc-shaped contact to move along an arc, the first terminal and the second terminal are arranged on the arc, wherein a first output terminal of the vacuum switch is electrically connected to the first terminal, a second output terminal of the vacuum switch is electrically connected to a first terminal of the parallel load switch, the second terminal is electrically connected to a second terminal of the parallel load switch, and the other end of the rotary drive conductive rod is electrically connected to a third terminal of the parallel load switch.