High-voltage vacuum capacitor

Abstract

The utility model discloses a high-voltage vacuum capacitor, which comprises an insulating shell, a first electrode disc, a second electrode disc, a first electrode fixed on the first electrode disc and a second electrode fixed on the second electrode disc, and a vacuum chamber is formed among the insulating shell, the first electrode disc and the second electrode disc. The first electrode and the second electrode are accommodated in the vacuum chamber in a mutual coupling manner; the first electrode and the second electrode are both made of conductive metal materials with the brinell hardness larger than 50 HB. A plurality of annular or spiral protruding structures are arranged on the peripheral face of the insulating shell so that the outer surface of the insulating shell can be in an uneven corrugated shape. According to the utility model, by adopting the structural design combination of the corrugated insulating shell and the high-hardness electrode, the withstand voltage of the vacuum capacitor is greatly improved, the aim of improving the working withstand voltage of the vacuum capacitor by more than 50% is fulfilled under the condition of ensuring small volume, and the requirements of high power and miniaturization of a user are met.

Description

Technical Field

[0001] This utility model relates to the field of capacitor technology, and in particular to a high-voltage vacuum capacitor. Background Technology

[0002] A vacuum capacitor is a type of capacitor with a ceramic insulating shell, a vacuum dielectric, and high-conductivity oxygen-free copper electrodes. Compared to other capacitors, it has advantages such as high voltage withstand capability, large current carrying capacity, low high-frequency loss, and self-healing ability after transient overload, making it particularly suitable for high-frequency, high-voltage applications. Currently, vacuum capacitors are widely used in equipment such as broadcasting, medical MRI, high-frequency heating, semiconductor etching, and plasma cleaning. In these high-frequency devices, vacuum capacitors form resonant circuits with high-frequency inductors to achieve high-frequency impedance matching and realize stable transmission of radio frequency power.

[0003] As shown in the attached figure Figure 1 As shown, a traditional vacuum capacitor 100 mainly comprises upper and lower electrode rings, upper and lower electrode disks, and a ceramic insulating shell. The upper and lower electrode rings are welded and fixed to the upper and lower electrode disks at high temperatures, and the two electrode disks are then connected to the ceramic insulating shell using high-temperature welding technology. The electrode rings are typically made of pure copper with an impurity content of ≤0.03%. During the welding process, the high temperatures cause a sharp decrease in the hardness of the electrode rings made of oxygen-free copper. Typically, the Brinell hardness of the electrode rings in their soft state is <50HB. Electrode rings with low hardness are prone to deformation under high-intensity electric fields, causing changes in the distance between the electrodes and a decrease in the insulation strength between them, thus making it difficult to increase the withstand voltage of the vacuum capacitor.

[0004] Meanwhile, traditional ceramic insulating shells are straight-walled cylindrical shapes. In humid or dusty environments, the insulation performance of the ceramic shells is unstable, and the actual operating voltage of the capacitor is easily affected by the environment and reduced.

[0005] Therefore, it is necessary to improve existing technologies to overcome their shortcomings. Utility Model Content

[0006] The problem to be solved by this invention is to provide a high-voltage vacuum capacitor to overcome the defects of existing vacuum capacitors, such as low withstand voltage and low insulation strength between electrodes.

[0007] The technical solution adopted by this utility model to solve its technical problem is: a high-voltage vacuum capacitor, comprising: an insulating shell, a first electrode disk, a second electrode disk, a first electrode fixed to the first electrode disk, and a second electrode fixed to the second electrode disk. A vacuum chamber is formed between the insulating shell, the first electrode disk, and the second electrode disk. The first electrode and the second electrode are coupled to each other and housed in the vacuum chamber. Both the first electrode and the second electrode are made of a conductive metal material with a Brinell hardness > 50HB. The outer circumferential surface of the insulating shell is provided with multiple annular or spiral protrusions to make its outer surface present an uneven corrugated shape.

[0008] As a further improvement of this utility model, a first connector is fixed in the middle of the first electrode disk, and a second connector is fixed in the middle of the second electrode disk, which is vertically opposite to the first connector and coaxially distributed. A positioning ceramic shaft is provided between the first connector and the second connector, and both the first electrode and the second electrode are coaxially distributed with the positioning ceramic shaft.

[0009] As a further improvement of this utility model, both the first connector and the second connector are provided with positioning slots at their ends facing each other, and the two ends of the positioning ceramic shaft are respectively inserted into the two positioning slots.

[0010] As a further improvement of this invention, at least one of the two positioning slots is equipped with a getter for adsorbing gas in the vacuum chamber.

[0011] As a further improvement of this utility model, the high-voltage vacuum capacitor also includes a transmission mechanism that is connected to the first electrode disk. The transmission mechanism is used to drive the first electrode disk and the first electrode to move, so as to change the coupling area between the first electrode and the second electrode.

[0012] As a further improvement of this utility model, the high-voltage vacuum capacitor also includes an end cap, a bellows, and a sleeve. The insulating shell is a cylindrical shape with open ends. The end cap and the second electrode disk are respectively sealed and welded to the two ends of the insulating shell. The first electrode disk is sealed and connected to the end cap through the bellows. The sleeve is fixed on the end cap. The transmission mechanism includes a screw. The screw is rotatably mounted on the sleeve and threadedly connected to the first connector.

[0013] As a further improvement of this utility model, the insulating shell is a cylindrical shape with open ends, and the first electrode disk and the second electrode disk are respectively sealed and welded to the two ends of the insulating shell.

[0014] As a further improvement of this utility model, both the first electrode and the second electrode are composed of multiple concentric electrode rings.

[0015] As a further improvement of this utility model, both the first electrode and the second electrode are made of conductive metal material with a relative permeability of <1.01μr.

[0016] As a further improvement of this utility model, the first electrode and the second electrode are made of stainless steel and its composite materials or molybdenum.

[0017] The beneficial effects of this utility model are as follows: This utility model provides a high-voltage vacuum capacitor. By adopting a combination of a corrugated insulating shell and high-hardness electrodes, the deformation of the first and second electrodes caused by high-temperature welding is avoided, thereby improving the insulation strength between the electrodes of the vacuum capacitor. At the same time, the insulation performance of the insulating shell is also improved, which greatly increases the withstand voltage of the vacuum capacitor. While ensuring a small size, the working withstand voltage of the vacuum capacitor is increased by more than 50%, meeting the user's requirements for high power and miniaturization. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of a traditional high-voltage vacuum capacitor.

[0019] Figure 2 This is a cross-sectional view of Embodiment 1 of the high-voltage vacuum capacitor of this utility model;

[0020] Figure 3 This is a cross-sectional view of Embodiment 2 of the high-voltage vacuum capacitor of this utility model;

[0021] Figure 4 This is a cross-sectional view of Embodiment 3 of the high-voltage vacuum capacitor of this utility model;

[0022] Figure 5 This is a cross-sectional view of Embodiment 4 of the high-voltage vacuum capacitor of this utility model.

[0023] Referring to the accompanying drawings, the following explanations are provided:

[0024] 1. Insulating outer shell; 101. Vacuum chamber; 102. Raised structure; 2. First electrode disk; 3. Second electrode disk; 4. First electrode; 5. Second electrode; 6. First connector; 7. Second connector; 8. Positioning ceramic shaft; 9. Getter; 10. End cap; 11. Bellows; 12. Sleeve; 13. Screw; 100. Conventional vacuum capacitor. Detailed Implementation

[0025] The preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0026] Example 1

[0027] See Figure 2This utility model provides a high-voltage vacuum capacitor, comprising: an insulating shell 1, a first electrode disk 2, a second electrode disk 3, a first electrode 4, and a second electrode 5; wherein, the first electrode 4 is fixed to the first electrode disk 2, and the second electrode 5 is fixed to the second electrode disk 3. A vacuum chamber 101 is formed between the insulating shell 1, the first electrode disk 2, and the second electrode disk 3, and the first electrode 4 and the second electrode 5 are coupled and housed in the vacuum chamber 101.

[0028] In this embodiment, the high-voltage vacuum capacitor is a fixed vacuum capacitor, that is, its capacitance is constant. The insulating shell 1 is a cylindrical shape with open ends. The first electrode disk 2 is sealed and welded to the upper end of the insulating shell 1, and the second electrode disk 3 is sealed and welded to the lower end of the insulating shell 1, thereby forming a sealed vacuum chamber 101 between the insulating shell 1 and the first electrode disk 2 and the second electrode disk 3.

[0029] Furthermore, the first electrode 4 is welded and fixed to the bottom surface of the first electrode disk 2, and the second electrode 5 is welded and fixed to the top surface of the second electrode disk 3. In this invention, both the first electrode 4 and the second electrode 5 are composed of multiple concentrically spaced cylindrical electrode rings, and the electrode rings of the first electrode 4 and the second electrode 5 extend into each other, presenting a cross distribution, so that there is a certain coupling area between the first electrode 4 and the second electrode 5.

[0030] As a significant improvement of this application, both the first electrode 4 and the second electrode 5 are made of conductive metal material with a Brinell hardness > 50HB. By using high-hardness electrode materials, the shape and size of the first electrode 4 and the second electrode 5 do not change after high-temperature welding, and the distance between the first electrode 4 and the second electrode 5 remains stable. This improves the insulation strength between the electrodes of the vacuum capacitor, resulting in a significant increase in the withstand voltage of the vacuum capacitor.

[0031] Preferably, the first electrode 4 and the second electrode 5 are made of materials with a relative permeability of <1.01μr, which can avoid hysteresis loss, reduce the influence of the magnetic field generated by the vacuum capacitor during operation on surrounding circuits or components, reduce unnecessary electromagnetic coupling with surrounding circuits or components, reduce the risk of electromagnetic interference, and at the same time, the low permeability material helps to maintain the uniformity and stability of the electric field between the capacitor electrodes, thereby ensuring the stability and accuracy of the capacitance value and ensuring that the vacuum capacitor can work normally under high voltage environment.

[0032] For example, the first electrode 4 and the second electrode 5 are made of stainless steel and its composite materials (such as stainless steel plated with copper or silver) or molybdenum. For instance, the first electrode 4 and the second electrode 5 are made of stainless steel with higher hardness, and the hardness can still reach HB150 or higher after high-temperature welding. Moreover, the shape and size of the electrodes do not deform during the high-temperature welding process, and the electrode spacing is stable and controlled.

[0033] As another important improvement of this application, the outer peripheral surface of the insulating shell 1 is provided with a plurality of annular protrusions 102, so that its outer surface presents an uneven corrugated shape.

[0034] The multiple annular protrusions 102 can be arranged at intervals along the axial direction of the insulating shell 1 or arranged continuously; the multiple annular protrusions 102 can be of the same shape or different shapes, and can be uniform or designed as non-uniform shapes with multiple curvatures.

[0035] like Figure 2 As shown, in this embodiment, the raised structure 102 on the outer surface of the insulating shell 1 is designed as a uniform arc shape. This design increases the creepage distance on the outer surface of the insulating shell 1 by about 1.7 times, thus significantly improving the insulation strength of the insulating shell 1. This ensures that the working voltage of the vacuum capacitor is more stable, and reduces the influence of the humid environment on the withstand voltage of the vacuum capacitor, thereby further improving the withstand voltage capability of the vacuum capacitor.

[0036] In this embodiment, the insulating shell 1 is made of ceramic.

[0037] The high-voltage vacuum capacitor of this invention also includes a first connector 6 and a second connector 7. In this embodiment, the first connector 6 and the second connector 7 have the same structure and both have threaded holes to facilitate the installation and use of the vacuum capacitor. The first connector 6 is welded at high temperature to the center of the first electrode disk 2, and the second connector 7 is welded at high temperature to the center of the second electrode disk 3. The second connector 7 and the first connector 6 are vertically opposite each other and coaxially distributed.

[0038] As another improvement of this application, a positioning ceramic shaft 8 is provided between the first connector 6 and the second connector 7, and the first electrode 4 and the second electrode 5 are both coaxially distributed with the positioning ceramic shaft 8.

[0039] Specifically, the ends of the first connector 6 and the second connector 7 facing each other both extend into the vacuum chamber 101. At the same time, the ends of the first connector 6 and the second connector 7 facing each other are provided with positioning slots that are adapted to the size of the positioning ceramic shaft 8. The two ends of the positioning ceramic shaft 8 are respectively inserted into the two positioning slots.

[0040] It is understandable that the positioning ceramic shaft 8 can be fixedly connected to the first connector 6 and the second connector 7, or it can be non-fixedly connected.

[0041] This invention adds a positioning ceramic shaft 8 between the first electrode disk 2 and the second electrode disk 3, making the first electrode 4 and the second electrode 5 coaxial, thereby further ensuring a stable and consistent distance between the electrodes.

[0042] It is worth mentioning that at least one of the two positioning slots is equipped with a getter 9 for adsorbing gas in the vacuum chamber 101.

[0043] In this embodiment, the getter 9 is a high-density non-evaporable getter made of multi-element alloy powder. The getter 9 has the characteristic that it can adsorb gas for a long time at room temperature after high-temperature activation, which can improve the vacuum degree inside the vacuum capacitor.

[0044] Example 2

[0045] See Figure 3 The difference between this embodiment and Embodiment 1 is that the shape of the protruding structure 102 is different.

[0046] Specifically, in this embodiment, the curvature of the raised structure 102 on the outer surface of the insulating shell 1 is increased, which can further improve the creepage distance on the outer surface of the insulating shell 1.

[0047] Example 3

[0048] See Figure 4 The difference between this embodiment and Embodiment 1 or Embodiment 2 is that the shape of the protrusion structure 102 is different.

[0049] Specifically, in this embodiment, the raised structure 102 on the outer surface of the insulating shell 1 includes a plurality of first protrusions and a plurality of second protrusions, which are arranged alternately along the axial direction of the insulating shell 1. The shape of the first protrusion is the same as that of the raised structure 102 in Embodiment 1, that is, the first protrusion is designed as an arc; the shape of the second protrusion is the same as that of the raised structure 102 in Embodiment 2, that is, the arc curvature of the second protrusion is increased.

[0050] Example 4

[0051] The difference between this embodiment and Embodiment 1, Embodiment 2, or Embodiment 3 is that in this embodiment, the high-voltage vacuum capacitor is a variable vacuum capacitor, that is, its capacitance value can be adjusted.

[0052] See Figure 5The high-voltage vacuum capacitor also includes a transmission mechanism connected to the first electrode disk 2. The transmission mechanism is used to drive the first electrode disk 2 and the first electrode 4 to move under the drive of an external driving device such as a motor, so as to change the coupling area between the first electrode 4 and the second electrode 5, thereby realizing the adjustment of the capacitance value of the high-voltage vacuum capacitor.

[0053] Specifically, the high-voltage vacuum capacitor also includes an end cap 10, a bellows 11, and a sleeve 12. The insulating shell 1 is a cylindrical shape with open ends. The end cap 10 and the second electrode disk 3 are respectively sealed and welded to the two ends of the insulating shell 1. The first electrode disk 2 is located in the cavity enclosed by the end cap 10, the second electrode disk 3, and the insulating shell 1, and the first electrode disk 2 is sealed and connected to the end cap 10 through the bellows 11. The sleeve 12 is fixed on the end cap 10. The transmission mechanism includes a screw 13, which is rotatably mounted on the sleeve 12 through bearings. The axial movement of the screw 13 is restricted, that is, the screw 13 can only rotate.

[0054] In this embodiment, the first connector 6 and the second connector 7 have different shapes. The first connector 6 is welded to the middle of the first electrode disk 2 by high temperature. Its upper end passes through the bellows 11 and is provided with a threaded hole. The screw 13 is threadedly connected to the threaded hole of the first connector 6.

[0055] In this embodiment, the lower end of the positioning ceramic shaft 8 is fixedly inserted into the positioning slot of the second connector 7, and the upper end of the positioning ceramic shaft 8 is slidably inserted into the positioning slot of the first connector 6.

[0056] When the motor drives the screw 13 to rotate, the screw 13 will drive the first connector 6 to move up and down along the axial direction, and simultaneously drive the first electrode disk 2 and the first electrode 4 to move, so as to change the coupling area between the first electrode 4 and the second electrode 5, thereby realizing the adjustment of the capacitance value of the high-voltage vacuum capacitor.

[0057] Example 5

[0058] The difference between this embodiment and embodiment one, two, three, or four is that in this embodiment, the raised structure 102 on the outer surface of the insulating shell 1 is spiral-shaped, which can also further increase the creepage distance on the outer surface of the insulating shell 1.

[0059] Therefore, it can be seen that the high-voltage vacuum capacitor of this utility model, by adopting a structural design combination of corrugated insulating shell 1 and high-hardness electrodes, avoids deformation of the first electrode 4 and the second electrode 5 during high-temperature welding, improves the insulation strength between the electrodes of the vacuum capacitor, and also improves the insulation performance of the insulating shell 1, so as to significantly improve the withstand voltage of the vacuum capacitor. While ensuring a small size, it achieves the goal of increasing the working withstand voltage of the vacuum capacitor by more than 50%, meeting the user's requirements for high power and miniaturization.

[0060] Many specific details have been set forth in the above description to provide a full understanding of this utility model. However, the above description is only a preferred embodiment of this utility model, and this utility model can be implemented in many other ways different from those described herein. Therefore, this utility model is not limited to the specific embodiments disclosed above. Furthermore, any person skilled in the art can make many possible variations and modifications to the technical solution of this utility model using the methods and techniques disclosed above, or modify it into equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of this utility model. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this utility model, without departing from the content of the technical solution of this utility model, shall still fall within the protection scope of the technical solution of this utility model.

Claims

1. A high-voltage vacuum capacitor comprising an insulating housing (1), a first electrode disc (2), a second electrode disc (3), a first electrode (4) fixed to the first electrode disc (2) and a second electrode (5) fixed to the second electrode disc (3), a vacuum chamber (101) being formed between the insulating housing (1) and the first electrode disc (2) and the second electrode disc (3), the first electrode (4) and the second electrode (5) being accommodated in the vacuum chamber (101) in a mutual coupling; characterized in that: The first electrode (4) and the second electrode (5) are made of conductive metal material with Brinell hardness > 50 HB; the outer circumferential surface of the insulating shell (1) is provided with a plurality of annular or spiral convex structures (102) so that the outer surface presents a concave-convex corrugated shape.

2. The high-voltage vacuum capacitor according to claim 1, characterized in that: The middle part of the first electrode disc (2) is fixed with a first connector (6), the middle part of the second electrode disc (3) is fixed with a second connector (7) which is opposite to the first connector (6) and coaxially distributed, a positioning porcelain shaft (8) is arranged between the first connector (6) and the second connector (7), and the first electrode (4) and the second electrode (5) are coaxially distributed with the positioning porcelain shaft (8).

3. The high-voltage vacuum capacitor according to claim 2, characterized in that: The end of the first connector (6) and the second connector (7) facing each other is provided with a positioning slot, and the two ends of the positioning porcelain shaft (8) are respectively inserted into the two positioning slots.

4. The high-voltage vacuum capacitor according to claim 3, characterized in that: At least one of the two positioning slots is mounted with a getter (9) for adsorbing gas in the vacuum chamber (101).

5. The high-voltage vacuum capacitor of claim 2, wherein: A transmission mechanism is further connected to the first electrode disc (2), which is used to drive the first electrode disc (2) and the first electrode (4) to move, so as to change the coupling area between the first electrode (4) and the second electrode (5).

6. The high-voltage vacuum capacitor according to claim 5, characterized in that: An end cover (10), a bellows (11) and a sleeve (12) are further included, the insulating shell (1) is a cylindrical shape with both ends open, the end cover (10) and the second electrode disc (3) are respectively sealed and welded at both ends of the insulating shell (1), the first electrode disc (2) is sealed and connected to the end cover (10) through the bellows (11); the sleeve (12) is fixed on the end cover (10), and the transmission mechanism includes a screw rod (13), the screw rod (13) is rotatably installed on the sleeve (12) and is threadedly connected to the first connector (6).

7. The high-voltage vacuum capacitor of claim 1, wherein: The insulating shell (1) is a cylindrical shape with both ends open, and the first electrode disc (2) and the second electrode disc (3) are respectively sealed and welded at both ends of the insulating shell (1).

8. The high-voltage vacuum capacitor of claim 1, wherein: The first electrode (4) and the second electrode (5) are both composed of a plurality of concentric electrode rings.

9. The high-voltage vacuum capacitor of claim 1, wherein: The first electrode (4) and the second electrode (5) are made of conductive metal material with relative magnetic permeability < 1.01 μr.

10. The high-voltage vacuum capacitor of claim 1, wherein: The first electrode (4) and the second electrode (5) are made of stainless steel and its composite material or molybdenum.

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