A porcelain shell assembly of a vacuum interrupter, a vacuum interrupter and a circuit breaker

Abstract

The application provides a porcelain shell assembly of a vacuum interrupter, a vacuum interrupter and a circuit breaker. The porcelain shell assembly of the vacuum interrupter comprises a porcelain shell, a shielding cylinder and a connecting ring. An inner wall of the porcelain shell is provided with a porcelain shell step. The shielding cylinder is arranged in the porcelain shell. The connecting ring has a horizontal section and a vertical section connected with each other. The horizontal section is fixedly abutted on the porcelain shell step. The shielding cylinder is fixed on the vertical section. A face of the horizontal section abutted on the porcelain shell step is defined as an abutted bottom face. An outer end portion of the abutted bottom face is provided with a notch. The electric field concentration degree of the notch portion is obviously reduced. The position of the connecting ring corresponding to the porcelain shell does not generate excessive electric field aggregation within the required voltage level, so that electric breakdown is effectively prevented.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of circuit breaker accessories, in particular to a porcelain shell assembly of a vacuum arc-extinguishing chamber, a vacuum arc-extinguishing chamber with the porcelain shell assembly and a circuit breaker with the vacuum arc-extinguishing chamber. BACKGROUND

[0002] When the ceramic vacuum arc-extinguishing chamber is subjected to electrical withstand test in air, breakdown may occur. The causes of breakdown are roughly divided into internal breakdown and external breakdown. The main causes of internal breakdown are that burrs on internal parts of the product are not removed cleanly, the internal structure is unreasonable, the gap between parts is too small, the internal electric field is unevenly distributed to concentrate in a certain position, and the internal vacuum degree is poor, etc. The main causes of external breakdown are that the performance of the porcelain shell does not meet the standard, the external environment is humid, etc.

[0003] For the method of preventing electrical breakdown, most of the current solutions are to optimize the structure and placement position of the internal parts of the arc-extinguishing chamber, increase the wall thickness of the porcelain shell, and externally glue, etc.

[0004] However, the current gluing method requires special gluing instruments and equipment, and a mold needs to be specially opened for a certain type of product. Moreover, the mold is not highly replaceable. This increases the cost of the glued product.

[0005] Increasing the thickness of the ceramic shell and the size of the product will also greatly increase the cost, and increasing the size of the product means changing the shape of the product, which may cause interference with other matching products or matching parts, or even the phenomenon that they cannot be matched. SUMMARY

[0006] Therefore, the present application provides a solution to the problem of electrical breakdown caused by product miniaturization and small internal fitting gap. A porcelain shell assembly of a vacuum arc-extinguishing chamber, a vacuum arc-extinguishing chamber and a circuit breaker are provided to improve the electrical breakdown resistance of the product without increasing the size of the product.

[0007] To achieve the above-mentioned purpose, the technical solutions provided by the present application are as follows:

[0008] A porcelain shell assembly of a vacuum arc-extinguishing chamber, comprising a porcelain shell, a shielding cylinder and a connecting ring, wherein an inner wall of the porcelain shell is provided with a porcelain shell step, the shielding cylinder is arranged in the porcelain shell, the connecting ring has a horizontal section and a vertical section connected to each other, the horizontal section is fixedly abutted on the porcelain shell step, the shielding cylinder is fixed on the vertical section, a face of the horizontal section abutting on the porcelain shell step is defined as an abutting bottom face, and an outer end portion of the abutting bottom face is provided with a notch.

[0009] Further, the wall surface of the notch and the abutting bottom face are transitioned at a right angle.

[0010] Further, the connecting ring has a notch at the outer end abutting the bottom surface.

[0011] Further, the connecting ring has a notch at the outer end abutting the bottom surface.

[0012] Further, the connecting ring has a notch at the outer end abutting the bottom surface.

[0013] Further, the connecting ring has a notch at the outer end abutting the bottom surface.

[0014] Further, the connecting ring has a notch at the outer end abutting the bottom surface.

[0015] Further, the connecting ring has a notch at the outer end abutting the bottom surface.

[0016] A vacuum arc-extinguishing chamber, at least comprising the porcelain shell assembly of the vacuum arc-extinguishing chamber.

[0017] A circuit breaker, at least comprising the vacuum arc-extinguishing chamber.

[0018] The technical solution provided by the application has the following beneficial effects:

[0019] The notch at the outer end abutting the bottom surface can significantly reduce the electric field concentration in the notch part, and the corresponding porcelain shell position of the connecting ring will not generate excessive electric field concentration within the required voltage level, thereby effectively preventing electrical breakdown.

[0020] Meanwhile, the application also has:

[0021] 1. The application is an innovative optimization reconstruction based on the original parts, which will not affect the assembly and use of the original product, so the relevant manufacturers or use places can still be used normally (there will be no situation that changing the key parts leads to changes in the appearance, thereby causing the failure between the matching parts). And the labor cost will not increase due to the use of the part.

[0022] 2. The application can ensure that the product reaches the required withstand voltage level without expanding the product size or under the original size or miniaturization requirement. This makes the product itself cost not increase, but also can further reduce the cost.

[0023] 3. The vacuum arc-extinguishing chamber of the application can not intentionally thicken the porcelain shell, thereby not changing the original porcelain shell size. This makes the porcelain shell mold cost, material cost, and related supporting manufacturer conversion supporting equipment cost can be saved. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The structure of the connecting ring in the embodiment is shownFigure 1

[0025] Figure 2 Fig. 3 shows a structural schematic of the connecting ring in the embodiment; Figure 2

[0026] Figure 3 Fig. 4 shows a sectional view of the connecting ring in the embodiment;

[0027] Figure 4 Fig. 5 shows a structural sectional view of the porcelain shell assembly of the vacuum interrupter in the embodiment;

[0028] Figure 5 Fig. 6 shows a structural schematic of the A area in Fig. 5; Figure 4

[0029] Figure 6 Fig. 7 shows a sectional view of the porcelain shell in the embodiment;

[0030] Figure 7 Fig. 8 shows an electric field distribution diagram of the porcelain shell assembly of the vacuum interrupter in the embodiment;

[0031] Figure 8 Fig. 9 shows an electric field distribution diagram of the porcelain shell assembly of the vacuum interrupter without notch in the prior art. DETAILED DESCRIPTION

[0032] To further explain the embodiments, the present application provides the accompanying drawings. These drawings are part of the disclosure of the present application, which mainly serve to illustrate the embodiments, and can be used to explain the operating principles of the embodiments in conjunction with the relevant description of the specification. Those of ordinary skill in the art should understand other possible implementations and advantages of the present application in conjunction with these contents. The components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0033] The present application is further explained in conjunction with the accompanying drawings and specific embodiments.

[0034] Reference is made to Figures 1 to 6 ​​​As shown, the embodiment provides a porcelain shell assembly of vacuum interrupter, which comprises a porcelain shell 20, a shielding cylinder 30 and a connecting ring 10. The inner wall of the porcelain shell 20 is provided with a porcelain shell step 21. The shielding cylinder 30 is arranged in the porcelain shell 20. The connecting ring 10 has a horizontal section 11 and a vertical section 12 connected, i.e. the cross section is substantially an L-shaped structure. In the embodiment, the material of the connecting ring 10 is stainless steel. The horizontal section 11 and the vertical section 12 are connected through an arc section 13. The horizontal section 11 is fixedly abutted on the porcelain shell step 21. The shielding cylinder 30 is fixed on the vertical section 12. Specifically, the abutting mode of the horizontal section 11 on the porcelain shell step 21 and the fixing mode of the shielding cylinder 30 on the vertical section 12 can be realized by riveting. The end of the shielding cylinder 30 is sleeved on the vertical section 12 and fixed by riveting.

[0035] The face of the horizontal section 11 abutting on the porcelain shell step 21 is defined as an abutting bottom face 111. The outer end of the abutting bottom face 111 is provided with a notch 101. In this way, the electric field concentration degree of the notch 101 part is obviously reduced. The position of the connecting ring 10 corresponding to the porcelain shell 20 will not produce excessive electric field aggregation within the required voltage level, thereby effectively preventing electric breakdown.

[0036] As shown, Figure 5 The area of the notch 101 is defined as an inner part a. The peripheral arc area of the end of the horizontal section 11 of the connecting ring 10 is defined as an outer part b. Normally, excessive electric field aggregation phenomenon will occur in the outer part b and the inner part a. The weakening of the electric field of the inner part a will also weaken the electric field aggregation phenomenon of the outer part b to a certain extent. By selecting the weakening of the electric field of the inner part a, the electric field aggregation phenomenon of the outer part b is further improved under the condition of effectively reducing the electric field aggregation of the inner part a. Therefore, the weakening of the electric field of the inner part a is more difficult to cause electric field excessive aggregation in the area and thus cause breakdown danger than the case without weakening the electric field.

[0037] The ANSYS Maxell electromagnetic field analysis software is used to simulate the electric field distribution. The product of the application is compared with the product before improvement. As shown in Figure 7 which is the electric field distribution diagram of the porcelain shell assembly of the vacuum interrupter in the embodiment; and as shown in Figure 8 which is the electric field distribution diagram of the porcelain shell assembly of the vacuum interrupter without notch in the prior art. The difference between the product of the application and the product before improvement is that the outer end of the abutting bottom face 111 of the product of the application is provided with a notch 101. The voltage of the experiment is 150kv (moving end 150kv, static end 0kv). It can be concluded that the gap position of the corner of the contact surface between the arc-shaped end of the connecting ring 10 and the porcelain shell step 21 of the product without notch 101 (i.e. the product before improvement) will produce a large amount of electric field concentration phenomenon (i.e. as shown in Figure 8As shown, the electric field of position b and position c are both concentrated, i.e. the electric field is higher relative to the periphery, and the high electric field of position c extends to the ceramic shell step 21, making the area of the ceramic shell 20 prone to breakdown. After the notch 101 (i.e. the product of the present application) is provided, the notch 101 position forms an energy barrier to prevent the electric field from spontaneously concentrating there, and the space in the notch 101 is in a vacuum state environment (e.g. Figure 7 As shown, position a is the space where the notch 101 is located; and Figure 8 The electric field at position a is significantly lower than that at position c Figure 8 In the electric field of position c, if you want to break down the ceramic shell 20, the electric field needs to be concentrated to form a strong electric field area, thereby attracting an arc to gather in this area. However, due to the notch 101 structure in this area, the original geometry that easily allows the electric field to concentrate is destroyed, resulting in the dispersion of the electric charge that was originally concentrated in this area, reducing the charge density. Therefore, more external energy is required to cross the energy barrier. Therefore, with the notch 101 structure, it is better to prevent excessive electric field concentration in this area, thereby reducing the risk of breakdown of the ceramic shell 20. The ceramic shell 20 at this position can be protected from electrical breakdown at the required voltage level.

[0038] Further, the wall 102 of the notch 101 and the abutting bottom surface 111 are at a right angle. In this way, the abutting bottom surface 111 of the horizontal section 11 of the connecting ring 10 is in contact with the ceramic shell step 21 without any gap, forming an insulating state, while the notch 101 and the ceramic shell step 21 have a large gap to form an energy barrier, directly transitioning from a state without a gap to a state with an energy barrier; preventing the wall 102 of the notch 101 and the abutting bottom surface 111 from forming a small gap due to the chamfer, which causes the electric field to concentrate (the electric field is prone to concentrate at the corner gap), ultimately increasing the risk of breakdown.

[0039] Further, since the electric field is prone to concentrate in the sharp corner area, the more sharp corners in the notch, the more the electric field is prone to concentrate, and the greater the risk of breakdown. Therefore, the connecting ring 10 has and only has the notch 101 at the outer end of the abutting bottom surface 111. It can be understood that the protection effect of the energy barrier formed by the electric field of the structure of the notch 101 provided at the outer end of the abutting bottom surface 111 is much greater than the impact caused by the formation of sharp corners.

[0040] Further, the horizontal section 11 and the vertical section 12 are connected by an arc section 13. In this way, the sharp corner structure of the connecting ring 10 is reduced, preventing the electric field from concentrating in the sharp corner position and increasing the risk of breakdown.

[0041] In the prior art, the outer wall surface of the porcelain shell 20 corresponding to the porcelain shell step 21 is a concave-convex surface (not a straight wall surface), the outer end of the abutting bottom surface 111 of the connecting ring 10 is closest to the position of the trough of the concave-convex surface 222, when the electric field is concentrated at the outer end of the abutting surface of the connecting ring, the porcelain shell breakdown is more likely to occur, therefore, a notch 101 is arranged at the outer end of the abutting bottom surface 111 of the connecting ring 10 to weaken the electric field concentration phenomenon, and the outer wall surface of the porcelain shell is further thickened to further reduce the risk of porcelain shell breakdown. Specifically, the outer wall surface of the porcelain shell 20 corresponding to the porcelain shell step 21 is a straight wall surface 221, so that the wall thickness of the porcelain shell 20 at this position is substantially the same, and the pressure resistance performance is guaranteed. More specifically, the outer wall surface of the porcelain shell 20 staggered with the porcelain shell step 21 is a concave-convex surface 222, that is, the upper and lower wall surfaces of the straight wall surface 221 are concave-convex surfaces 222, which are specifically similar to corrugated wall surfaces, and can increase the creepage distance. The thickness of the straight wall surface 221 of the porcelain shell 20 is equal to the maximum thickness of the concave-convex surface 222 (that is, the total wall thickness of the straight wall surface region and the other corrugated regions is the same, and the wall thickness does not need to be thickened to increase the size and cost). In this way, the concave-convex surface 222 of the outer wall of the porcelain shell 20 guarantees sufficient creepage distance outside, and the outer wall of the local porcelain shell region corresponding to the connecting ring 10 is provided with a straight wall, which further reduces the risk of breakdown.

[0042] The embodiment also provides a vacuum arc-extinguishing chamber, which at least comprises the porcelain shell assembly of the vacuum arc-extinguishing chamber.

[0043] The embodiment also provides a circuit breaker, which at least comprises the vacuum arc-extinguishing chamber.

[0044] Meanwhile, the scheme provided by the application also has the following effects:

[0045] 1. The application is an innovative optimization reconstruction based on the original part, which does not affect the assembly and use of the original product, so that the related manufacturers or use places can still be normally used (without the case that the change of the key part leads to the change of the appearance, thereby causing the failure between the matching parts). And the labor cost will not increase due to the use of the part.

[0046] 2. The application can guarantee the pressure resistance level required in the case of not expanding the product size or miniaturization, which makes the product cost not increase, and can further reduce the cost.

[0047] 3. The vacuum arc-extinguishing chamber of the application can not intentionally thicken the porcelain shell, so that the original porcelain shell size is not changed. This can save the mold cost, material cost and related supporting equipment conversion cost of the porcelain shell.

[0048] Although the present application has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details can be made therein without departing from the spirit and scope of the application as defined in the appended claims.

Claims

1. A ceramic shell assembly for a vacuum interrupter, comprising a ceramic shell, a shielding cylinder, and a connecting ring, wherein the inner wall of the ceramic shell is provided with a ceramic shell step, the shielding cylinder is disposed inside the ceramic shell, and the connecting ring has a connected horizontal segment and a vertical segment, the horizontal segment being fixedly abutting against the ceramic shell step, and the shielding cylinder being fixed to the vertical segment, characterized in that: The surface of the horizontal segment that abuts against the ceramic shell step is defined as the abutting bottom surface, and the outer end of the abutting bottom surface is provided with a notch.

2. The ceramic shell assembly of the vacuum interrupter according to claim 1, characterized in that: The wall of the notch transitions at a right angle to the bottom surface of the contact.

3. The ceramic shell assembly of the vacuum interrupter according to claim 1, characterized in that: The connecting ring has a notch only at its outer end that abuts the bottom surface.

4. The ceramic shell assembly of the vacuum interrupter according to claim 1, characterized in that: The horizontal and vertical segments of the connecting ring are connected by an arc segment.

5. The ceramic shell assembly of the vacuum interrupter according to claim 1, characterized in that: The connecting ring is made of stainless steel.

6. The ceramic shell assembly of the vacuum interrupter according to claim 1, characterized in that: The outer wall surface of the ceramic shell corresponding to the ceramic shell step is a straight wall surface.

7. The ceramic shell assembly of the vacuum interrupter according to claim 6, characterized in that: The outer wall surface of the ceramic shell, which is offset from the ceramic shell steps, has an uneven surface.

8. The ceramic shell assembly of the vacuum interrupter according to claim 7, characterized in that: The thickness of the ceramic shell at the straight wall position is equal to the maximum thickness at the uneven wall position.

9. A vacuum interrupter, characterized in that: It includes at least the ceramic shell assembly of the vacuum interrupter as described in any one of claims 1 to 8.

10. A circuit breaker, characterized in that: It includes at least the vacuum interrupter chamber as described in claim 9.

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