Vacuum arc-extinguishing chamber
By setting eddy current notches and an electric field complementary structure of a horseshoe-shaped iron core on the contacts, the problems of electric field superposition and eddy current temperature rise in the vacuum interrupter are solved, stable arc extinguishing and efficient heat dissipation of the contacts are achieved, and the safety and reliability of the equipment are improved.
Patent Information
- Application Number
- CN202422518048.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-17
- Publication Date
- 2025-09-26
- Estimated Expiration
- 2034-10-17
AI Technical Summary
The existing vacuum interrupter has holes on the contacts, which causes the electric fields to overlap, easily causing electric shock, electric sparks, and damage to the insulation of electrical appliances. Eddy currents also cause large temperature rises, and the existing structure cannot effectively avoid arc accumulation and contact erosion.
An eddy current cutout is set on the contact, combined with a horseshoe-shaped iron core to form an electric field complementary structure, and the horseshoe-shaped iron core is fixed by a fixing plate. The eddy current cutout is located on the opening side of the iron core, cooperating with the generation of the longitudinal magnetic field to reduce eddy current and electric field concentration.
It achieves uniform distribution of the electric field, reduces temperature rise, avoids arc accumulation, improves the heat dissipation capacity and service life of the contacts, and ensures the safety and stability of electrical equipment.
Smart Images
Figure CN223390435U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of high-voltage electrical switches, in particular to a vacuum interrupter. Background Art
[0002] The vacuum interrupter, also known as the vacuum switch tube, is the core component of medium and high voltage power switches. Its main function is to quickly extinguish the arc after the medium and high voltage circuit is cut off from the power supply through the excellent insulation of the vacuum inside the tube, thus avoiding accidents and incidents. It is mainly used in power transmission and distribution control systems.
[0003] With the development of technology, the performance requirements of switchgear are getting higher and higher, which leads to higher requirements for vacuum interrupter. Adding a horseshoe-shaped iron core to the contact group can generate a longitudinal magnetic field, which can effectively prevent the arc from gathering to form a concentrated arc and causing excessive erosion of the contact surface. At the same time, according to the skin effect (the current is more concentrated in the area close to the outer surface of the conductor, and the closer to the center of the conductor, the smaller the current density), it is known that the current density at the periphery of the contact is very high; eddy currents will be generated, resulting in a large temperature rise; in this regard, the existing technology sets holes on the contacts to cut off the eddy currents. Although the method is effective, the holes of this structure are point-symmetrically distributed on the contacts. Such a setting easily leads to the superposition of electric fields, resulting in a greater electric field concentration effect, which can easily cause dangers such as electric shock, electric sparks, and electrical insulation damage. Utility Model Content
[0004] Therefore, the present invention provides a vacuum interrupter to solve the above problems.
[0005] To achieve the above purpose, the technical solutions provided by the present invention are as follows:
[0006] A vacuum interrupter comprises an insulating shell and two conductive rods, a moving contact assembly, and a static contact assembly arranged within the insulating shell. The two conductive rods are coaxial and oppositely arranged, and the moving contact assembly and the static contact assembly are respectively assembled on the two conductive rods. The moving contact assembly and the static contact assembly each comprise a horseshoe-shaped iron core and a contact, the horseshoe-shaped iron core having an unclosed open side. The contact is provided with an eddy current notch, and the eddy current notch is within the range of the open side of the horseshoe-shaped iron core.
[0007] Furthermore, on a projection plane perpendicular to the axial direction of the conductive rod, the opening side of the horseshoe-shaped core of the moving contact assembly and the opening side of the horseshoe-shaped core of the static contact assembly are oriented in opposite directions, forming an electric field complementary structure.
[0008] Furthermore, the structural relationship between the moving contact assembly and the static contact assembly is a structure obtained by mutual central reflection transformation; that is, the moving contact assembly is equivalent to the structure obtained by mirror symmetry of the static contact assembly and then rotating 180° around the central axis of the conductive rod.
[0009] Furthermore, the number of eddy current notches on the same contact is one.
[0010] Furthermore, the eddy current notch is a notch extending from the outer peripheral wall of the contact to the central area, and the diameter of the outer notch of the eddy current notch is larger than the diameter of the inner notch.
[0011] Furthermore, the contact is a circular contact, and the eddy current cut is a fan-shaped cut.
[0012] Furthermore, the two sector-shaped edges of the eddy current cutout are transitioned through an arc segment.
[0013] Furthermore, the angle of the eddy current cutout does not exceed 50°.
[0014] Furthermore, a contact through hole is provided in the central area of the contact and extends through to the contact surface thereof.
[0015] Furthermore, the side of the contact through hole facing the contact surface is a trumpet-shaped hole segment with a gradually increasing hole diameter.
[0016] Furthermore, the moving contact assembly and the static contact assembly each include a fixing plate, which is fixedly connected to the conductive rod. The horseshoe-shaped iron core is formed by stacking multiple magnetic pole pieces and is fixed to the fixing plate by rivets.
[0017] Furthermore, a non-circular limiting slot is provided on the fixing plate, and the contact piece has a through hole located in the limiting slot; the cross-sectional shape of the end of the conductive rod is adapted to the limiting slot and a mounting boss is raised on the end face, and the mounting boss is inserted into the through hole of the contact piece, and the end of the conductive rod is assembled in the limiting slot to form a circumferential limiting fit.
[0018] The technical solution provided by the utility model has the following beneficial effects:
[0019] 1. This solution combines a horseshoe-shaped core with an eddy current cutout on the contact, located within the open side of the core. The contact exhibits a weak electric field area at the eddy current cutout, while the remaining intact area exhibits an enhanced electric field area. Furthermore, the eddy current cutout is located within the open side of the core, making the contrast between strong and weak areas more pronounced. This means that the eddy current cutout not only reduces the generation of weak eddy currents, thereby reducing temperature rise, but also works in conjunction with the horseshoe core to enhance the generation of the longitudinal magnetic field, further preventing arc accumulation and the formation of concentrated arcs, which can lead to excessive ablation of the contact surface.
[0020] 2. On a projection plane perpendicular to the axial direction of the conductive rod, the open sides of the horseshoe-shaped core of the moving contact assembly and the open sides of the horseshoe-shaped core of the static contact assembly face opposite directions, forming a complementary electric field structure. This arrangement ensures a balanced electric field strength between the two contact assemblies (moving and static), with the reinforced areas of one contact assembly directly corresponding to the weakened areas of the other. This one-to-one correspondence creates an overall uniform electric field and a stable longitudinal magnetic field, achieving arc extinguishing and ensuring a favorable electric field environment.
[0021] 3. A fixed plate structure is adopted, and the contacts and horseshoe-shaped iron core are fixed on the fixed plate; the horseshoe-shaped iron core can be assembled in an exposed manner, which helps to improve the heat dissipation capacity of the contact assembly during experiments; it also facilitates assembly and realizes mass production, and is easy to correct errors and repair to improve the yield rate.
[0022] 4. The number of eddy current cuts on the same contact is only one, and a single cut is easy to process, avoiding the problem of multiple cuts requiring coordination with positioning references, weakening contact strength and causing failure.
[0023] 5. The contact is a circular contact, and the eddy current cut is a fan-shaped cut; a structure is formed in which the outer cut of the contact is large and the gap in the central area is small, which reduces the current density in the outer area while ensuring the contact area of the middle area, improves the utilization rate of the contact surface, further reduces the contact resistance, and reduces heat.
[0024] 6. A contact through-hole is provided in the central area of the contact, which passes through to its contact surface. Furthermore, the side of the contact through-hole facing the contact surface is a trumpet-shaped hole section with a gradually increasing aperture; this can reduce heat accumulation in the central area; at the same time, when the contacts are separated, heat overflows, and the trumpet-shaped hole section increases the heat dissipation area, thereby improving the heat dissipation efficiency of the contacts and reducing the temperature rise of the contacts. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 The figure shows a partial structural diagram of the vacuum interrupter in the embodiment;
[0026] Figure 2 The figure shows a schematic diagram of the matching structure of the contact, the fixing plate and the horseshoe-shaped iron core in the embodiment;
[0027] Figure 3 Shown Figure 2 a cross-sectional view of the structure shown;
[0028] Figure 4 Shown is a schematic diagram of the structure of the contact;
[0029] Figure 5 Shown Figure 2 a top view of the structure shown;
[0030] Figure 6 Shown is a schematic structural diagram of one of the conductive rods. DETAILED DESCRIPTION
[0031] To further illustrate various embodiments, the present invention is provided with accompanying drawings. These drawings form part of the disclosure of this invention and are primarily used to illustrate the embodiments and, in conjunction with the relevant description in the specification, to explain the operating principles of the embodiments. By referring to these drawings, those skilled in the art will understand other possible implementations and the advantages of this invention. The components in the figures are not drawn to scale, and similar reference numerals are generally used to represent similar components.
[0032] In the description of the present invention, the terms "up", "down", "left", "right", "front", "back" and other directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.
[0033] The present invention will now be further described with reference to the accompanying drawings and specific implementation methods.
[0034] Reference Figures 1 to 6 As shown, a vacuum interrupter provided in this embodiment includes an insulating housing (not shown) and two conductive rods 10, a moving contact assembly 1, and a static contact assembly 2 disposed within the insulating housing. The two conductive rods 10 are coaxial and oppositely disposed, and the moving contact assembly 1 and the static contact assembly 2 are respectively assembled on the two conductive rods 10. In this embodiment, the moving contact assembly 1 and the static contact assembly 2 are disposed correspondingly up and down. The moving contact assembly 1 and the static contact assembly 2 each include a horseshoe-shaped core 20 and a contact 30. The horseshoe-shaped core 20 has an unclosed open side 22. The contact 30 is a circular contact connected to the end of the conductive rod 10 and has a contact surface 301 facing the opposite contact. The horseshoe-shaped core 20 is disposed on the side away from the contact surface 301 of the contact 30. When the circuit breaker is closed, the contact surface 301 of the contact 30 of the moving contact assembly 1 contacts the contact surface 301 of the contact 30 of the static contact assembly 2.
[0035] The contact 30 is provided with an eddy current notch 31, and the eddy current notch 31 is located within the range of the open side 22 of the horseshoe core 20. Due to the configuration of the eddy current notch 31, the contact 30 has a weak electric field area at the eddy current notch 31, while the remaining intact portion has an electric field enhanced area. Furthermore, the eddy current notch 31 is located within the range of the open side 22 of the horseshoe core 20, so the contrast between the strong and weak areas is more obvious. In other words, the configuration of the eddy current notch 31 not only effectively reduces the generation of weak eddy currents, thereby reducing temperature rise, but also cooperates with the horseshoe core 20 to enhance the generation of a longitudinal magnetic field. That is, when a high voltage is connected from one end, current flows from the conductive rod 10 into the contact assembly, and the current path flows along the horseshoe core 20 through the contact 30. This process generates a longitudinal magnetic field due to the regular movement of electric charges. Finally, the current flows to the opposing contact 30, forming a loop. Because the eddy current cutouts 31 of the contact 30 are within the opening 22 of the horseshoe-shaped core 20 (i.e., the current paths are substantially aligned), the generated magnetic fields are superimposed, thereby enhancing the magnetic field. This further prevents arc accumulation from forming concentrated arcs and causing excessive erosion on the surface of the contact 30.
[0036] With the aforementioned vacuum interrupter structure, after the moving contact assembly 1 and the stationary contact assembly 2 are closed, the current density at the periphery of the contact 30 is very high, according to the skin effect (current is more concentrated in the area near the outer surface of the conductor, and the closer to the center of the conductor, the smaller the current density), thereby generating eddy currents. The provision of the eddy current notch 31 on the contact 30 can effectively cut off the eddy currents (i.e., it can effectively reduce the generation of weak eddy currents). At the same time, during the disconnection process between the moving contact assembly 1 and the stationary contact assembly 2, the horseshoe-shaped iron core 20, in conjunction with the provision of the eddy current notch 31 on the contact 30, can generate a stronger longitudinal magnetic field, effectively preventing arc aggregation from forming a concentrated arc and causing excessive ablation of the surface of the contact 30.
[0037] Further preferably, on a projection plane perpendicular to the axial direction of the conductive rod 10, the opening side 22 of the horseshoe-shaped core 20 of the moving contact assembly 1 and the opening side 22 of the horseshoe-shaped core 20 of the static contact assembly 2 are oriented in opposite directions, as shown in FIG. Figure 1-2 As shown, the eddy current notch 31 of the contact 30 of the moving contact assembly 1 and the open side 22 of the horseshoe-shaped iron core 20 are both facing right, then the right side of the moving contact assembly 1 is a weak electric field area, and the left side of the moving contact 1 is a strong electric field area; and the eddy current notch 31 of the contact 30 of the static contact assembly 2 and the open side 22 of the horseshoe-shaped iron core 20 are both facing left, then the right side of the static contact assembly 2 is a strong electric field area, and the left side of the static contact assembly 2 is a weak electric field area. In the open state, the strong electric field on the left side of the moving contact assembly 1 and the weak electric field on the left side of the static contact assembly 2 complement each other, and the weak electric field on the right side of the moving contact assembly 1 and the strong electric field on the right side of the static contact assembly 2 complement each other; such a one-to-one correspondence achieves the effect of a uniform electric field on the whole, and at the same time forms a stable longitudinal magnetic field, achieving the arc extinguishing goal and ensuring a good electric field environment.
[0038] More preferably, the structural relationship between the movable contact assembly 1 and the stationary contact assembly 2 is a structure obtained by mutual central reflection transformation; that is, the movable contact assembly 1 is equivalent to the structure of the stationary contact assembly 2 obtained by mirror symmetry and then circumferentially rotating 180 degrees about the central axis of the conductive rod 10. This arrangement ensures that the intensities of the strong and weak electric fields generated by the movable contact assembly 1 and the stationary contact assembly 2 are substantially identical and complementary, that is, the intensity of the strong electric field generated by the movable contact assembly 1 is substantially identical to the intensity of the strong electric field generated by the stationary contact assembly 2, and the intensity of the weak electric field generated by the movable contact assembly 1 is substantially identical to the intensity of the weak electric field generated by the stationary contact assembly 2; and the complementary electric field effect is more significant after the combination.
[0039] Furthermore, in this embodiment, the number of eddy current notches 31 on the same contact 30 is one, i.e., the number of eddy current notches 31 on the contact 30 of the movable contact assembly 1 and the number of eddy current notches 31 on the contact 30 of the stationary contact assembly 2 are both one; a single notch is easy to process. Of course, in other embodiments, multiple eddy current notches 31 may be provided on the same contact 30, and the number of eddy current notches 31 on the contact 30 of the movable contact assembly 1 and the number of eddy current notches 31 on the contact 30 of the stationary contact assembly 2 may also be different, such as providing multiple eddy current notches 31 on the same contact 30, as long as the multiple eddy current notches 31 are all within the range of the open side 22 of the horseshoe-shaped core 20. While the use of multiple eddy current notches 31 can also achieve the aforementioned effect of effectively reducing the generation of weak eddy currents and cooperating with the horseshoe-shaped core 20 to strengthen the longitudinal magnetic field, considering the application of arc extinguishing chambers using longitudinal magnetic contacts, they all require a large opening and closing force, which also results in the need for a large contact pressure. Therefore, providing multiple eddy current cutouts 31 on the contact 30 within the range of the open side 22 of the horseshoe core 20 may directly cause the contact 30 to crack, dent, etc. due to the large contact pressure during experimental operation, ultimately leading to arc extinguishing failure. Secondly, the more eddy current cutouts 31 are provided on the contact 30, the smaller its contact area, the greater the contact resistance, and the increase in temperature rise; finally, if multiple eddy current cutouts 31 are provided on the contact 30, for traditional contacts 30, although it can better balance the magnetic field generated by the contact 30, for structures with horseshoe cores 20, it is more necessary for the contact 30 to have an uneven distribution of magnetic fields, which is used to superimpose the magnetic field generated by the horseshoe core 20 to form distinct strong and weak magnetic field opposing areas, thereby achieving the strong and weak offset of the opposing electric fields at the dynamic and static ends. Therefore, it is more preferred to have one eddy current cutout 31 on the same contact 30.
[0040] Furthermore, in this embodiment, the contact 30 is a circular contact with no outer sharp edges to ensure contact breaking performance. Meanwhile, the eddy current notch 31 extends from the outer peripheral wall of the contact 30 toward the center, with the outer diameter of the eddy current notch 31 being larger than the inner diameter. More specifically, the eddy current notch 31 is configured as a fan-shaped notch, i.e., the diameter of the eddy current notch 31 decreases linearly from the outer edge to the inner edge. This creates a structure in which the outer notch of the contact 30 is larger and the central notch is smaller. Due to the skin effect, the current density at the outer periphery of the contact 30 is greater than that in the central region. The greater the current density, the stronger the eddy current effect, and the higher the contact temperature rise. Therefore, the design of a larger outer notch reduces the current density to a greater extent, weakens the eddy current effect, and further reduces the temperature rise. The smaller notch in the central region ensures a larger contact area in the central region of the contact 30, improving contact surface utilization. The larger the contact area in the central region, the lower the resistance, and further reduces the temperature rise. Therefore, through the design of the above-mentioned fan-shaped notch, the current density in the peripheral area is reduced while the contact area in the middle area is maintained, further reducing heat generation. Of course, in other embodiments, the eddy current notch 31 is not limited to a fan-shaped notch. For example, the notch diameter of the eddy current notch 31 can also be set to decrease in a step-by-step manner from the outside to the inside.
[0041] Further preferably, the angle of the eddy current cutout 31 does not exceed 50° to ensure sufficient contact area between the contacts 30 .
[0042] The central area of the contact 30 is provided with a contact through hole 32 extending to its contact surface 301; further, the side of the contact through hole 32 facing the contact surface 301 is a trumpet-shaped hole section 321 with a gradually increasing aperture; this can reduce heat accumulation in the central area; at the same time, when the contacts are separated, heat overflows, and the trumpet-shaped hole section 321 increases the heat dissipation area, thereby improving the heat dissipation efficiency of the contacts and reducing the temperature rise of the contacts.
[0043] The two sector edges of the eddy current cutout 31 are transitioned through an arc segment 311 to avoid tip discharge.
[0044] Both the movable contact assembly 1 and the stationary contact assembly 2 further include a fixing plate 40, which is fixedly connected to the conductive rod 10. The horseshoe core 20 is composed of multiple stacked pole pieces 21 and riveted to the fixing plate 40 via rivets 23. This arrangement enables the horseshoe core 20 to be assembled in an exposed manner, i.e., the horseshoe core 20 does not need to be covered by an outer cover, but is instead exposed within the enclosed space of the insulating housing. This improves the heat dissipation of the contact assemblies (i.e., the movable contact assembly 1 and the stationary contact assembly 2) during experiments; it also facilitates assembly, enabling mass production, and facilitating error correction and repair, thereby improving yield. Of course, in other embodiments, the fixing plate 40 may be omitted. When this is not the case, the horseshoe core 20 may be fixed to the conductive rod 10 via other means (e.g., via an outer cover), etc.
[0045] The fixing plate 40 is provided with a non-circular limiting slot 41. In this embodiment, the non-circular limiting slot is the structure remaining after a "D"-shaped area is cut out from a complete circle. The contact 30 has a through hole located within the limiting slot 41. Specifically, the through hole is the contact through hole 32. The cross-sectional shape of the end of the conductive rod 10 is adapted to the limiting slot 41, and a mounting boss 12 is raised on the end face 11. That is, the end face 11 of the end of the conductive rod 10 is also cut out of a "D"-shaped structure to form a limiting step 13. The mounting boss 12 is inserted into the contact through hole 32 of the contact 30, and the end of the conductive rod 10 is assembled into the limiting slot 41 to form a circumferential limiting fit. This arrangement improves alignment and prevents reverse installation. Of course, in other embodiments, the structure of the non-circular limiting slot 41 and the end of the conductive rod 10 adapted thereto is not limited thereto, and may also be a semicircle, a right triangle, a diamond or other irregular shaped structures.
[0046] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, those skilled in the art should understand that various changes can be made to the form and details of the present invention without departing from the spirit and scope of the present invention as defined by the appended claims, and all of these changes are within the scope of protection of the present invention.
Claims
1. A vacuum interrupter, comprising an insulating housing, two conductive rods, a movable contact assembly, and a stationary contact assembly disposed within the insulating housing, wherein the two conductive rods are coaxially and oppositely disposed, and the movable contact assembly and the stationary contact assembly are respectively assembled on the two conductive rods; the movable contact assembly and the stationary contact assembly each comprise a horseshoe-shaped core and a contact, the horseshoe-shaped core having an unsealed open side; and characterized in that: The contact is provided with an eddy current notch, and the eddy current notch is located within the range of the opening side of the horseshoe-shaped iron core.
2. The vacuum interrupter according to claim 1, wherein: On a projection plane perpendicular to the axial direction of the conductive rod, the opening side of the horseshoe-shaped core of the moving contact assembly and the opening side of the horseshoe-shaped core of the static contact assembly are oriented in opposite directions, forming an electric field complementary structure.
3. The vacuum interrupter according to claim 2, characterized in that: The structural relationship between the moving contact assembly and the static contact assembly is a structure obtained by mutual central reflection transformation; that is, the moving contact assembly is equivalent to the structure obtained by mirror symmetry of the static contact assembly and then rotating 180° around the central axis of the conductive rod.
4. The vacuum interrupter according to claim 1, 2 or 3, characterized in that: The number of eddy current notches on the same contact is one.
5. The vacuum interrupter according to claim 4, characterized in that: The eddy current notch is a notch extending from the outer peripheral wall of the contact to the central area, and the diameter of the outer notch of the eddy current notch is larger than the diameter of the inner notch.
6. The vacuum interrupter according to claim 5, characterized in that: The contact is a circular contact, and the eddy current cut is a fan-shaped cut.
7. The vacuum interrupter according to claim 6, characterized in that: The two sector edges of the eddy current cutout are transitioned through a circular arc segment.
8. The vacuum interrupter according to claim 6, characterized in that: The angle of the eddy current cutout does not exceed 50°.
9. The vacuum interrupter according to claim 1, characterized in that: A contact through hole is provided in the central area of the contact and penetrates to the contact surface thereof.
10. The vacuum interrupter according to claim 9, characterized in that: The side of the contact through hole facing the contact surface is a trumpet-shaped hole section with a gradually increasing hole diameter.
11. The vacuum interrupter according to claim 1, characterized in that: The moving contact assembly and the static contact assembly also include a fixing plate, which is fixedly connected to the conductive rod. The horseshoe-shaped iron core is formed by stacking multiple magnetic pole pieces and is fixed to the fixing plate by rivets.
12. The vacuum interrupter according to claim 11, characterized in that: A non-circular limiting slot is provided on the fixing plate, and the contact piece has a through hole located in the limiting slot; the cross-sectional shape of the end of the conductive rod is adapted to the limiting slot and a mounting boss is raised on the end face, and the mounting boss is inserted into the through hole of the contact piece, and the end of the conductive rod is assembled in the limiting slot to form a circumferential limiting fit.