High heat dissipation large current variable vacuum capacitor

Abstract

This invention discloses a high-heat-dissipation, high-current variable vacuum capacitor, comprising a housing and a moving electrode assembly, a metal bellows, and a stationary electrode, all disposed within the housing. The housing includes an insulating cylinder, a moving end base, and a stationary electrode disk. The moving end base is provided with a metal connecting cylinder. The moving electrode assembly includes a moving sub-disk and moving electrodes fixed to the moving sub-disk. The metal bellows is sealed between the moving end base and the moving sub-disk. The stationary electrode is fixed to the inner end face of the stationary electrode disk. A metal conductive component is fixedly mounted on the moving electrode assembly. The metal conductive component has sliding contacts that elastically abut against the inner wall of the metal connecting cylinder using their own elasticity. These contacts maintain sliding contact with the metal connecting cylinder throughout the entire stroke of the moving electrode assembly moving axially, thereby forming a conductive and heat dissipation path in parallel with the metal bellows between the moving electrode assembly and the moving end base. This invention can increase the conductive and heat dissipation areas of the vacuum capacitor, reduce the operating temperature, and increase the current carrying capacity.

Description

Technical Field

[0001] This invention relates to the field of vacuum capacitor technology, and in particular to a high-heat-dissipation, high-current variable vacuum capacitor. Background Technology

[0002] Vacuum capacitors mainly consist of two sets of electrodes coupled together and sealed within a vacuum chamber. The electrodes are typically made of high-conductivity oxygen-free copper with an impurity content of ≤0.03%, while the insulating shell is generally made of 95% alumina (Al2O3) ceramic material. However, due to the long-term operation of vacuum capacitors under high-frequency, high-current conditions, the current is significantly affected by the skin effect, concentrating only in the extremely thin surface layer of the electrodes and conductive components. This results in a substantial reduction in the effective conductive area and a sharp increase in Joule heat. Actual operating data shows that the surface operating temperature of a conventional vacuum capacitor can typically reach 125℃, and the core temperature of the internal electrodes can even exceed 250℃.

[0003] Increased temperature can cause a series of serious problems: on the one hand, high temperature can lead to a significant decrease in the insulation strength between electrodes in the vacuum chamber, directly reducing the withstand voltage performance of the capacitor and increasing the risk of high voltage breakdown; on the other hand, high temperature can cause thermal deformation of the electrode structure and slight changes in the vacuum dielectric constant, which in turn can cause temperature drift in the capacitance value of the capacitor, disrupt the impedance matching state of the high-frequency circuit, and affect the normal operation accuracy and stability of the equipment.

[0004] With the rapid development of high-end industries such as semiconductor manufacturing, the output power of RF impedance matching devices is constantly increasing, placing more stringent requirements on the high current carrying capacity and high voltage operation stability of the matching vacuum capacitors. To solve the temperature rise problem of vacuum capacitors, existing technologies mainly employ two methods: one is to add a circulating water cooling system, such as the technical solution disclosed in Chinese Patent Publication No. CN114121484A, which uses cooling water to remove the heat generated inside the capacitor; the other is to increase the diameter of the metal bellows, using the increased surface area of ​​the bellows to improve heat dissipation capacity.

[0005] However, both of the above-mentioned existing technologies have obvious drawbacks: adopting a circulating water cooling system will significantly increase the structural complexity of the product, requiring a separate cooling water circulation device, which not only increases the product size and installation space, but also increases the maintenance cost of the equipment, and poses a safety hazard of equipment failure due to cooling water leakage; while simply increasing the diameter of the metal bellows will significantly increase the stress area of ​​the bellows under atmospheric pressure, resulting in a significant increase in the adjustment torque of the capacitor, and this solution has very limited improvement in heat dissipation effect, which cannot meet the ever-increasing high current operating requirements of semiconductor equipment. Summary of the Invention

[0006] The purpose of this invention is to solve the above-mentioned problems in the prior art and provide a high-heat-dissipation, high-current variable vacuum capacitor. By setting a metal conductive element between the moving electrode group and the metal connecting cylinder of the moving end base, the conductive area and heat dissipation area of ​​the vacuum capacitor are increased, thereby reducing the operating temperature, increasing the current carrying capacity, and meeting the requirements of the semiconductor manufacturing equipment field for high current and voltage withstand stability of vacuum capacitors.

[0007] The technical solution adopted by this invention to solve its technical problem is: a high-heat dissipation, high-current variable vacuum capacitor, comprising: The outer casing includes an insulating cylinder and a moving end base and a stationary electrode disk that are respectively sealed and fixed at both axial ends of the insulating cylinder; A moving electrode assembly is disposed within the housing and is movable axially to adjust the capacitance of the vacuum capacitor. The moving electrode assembly includes a moving sub-disk and moving electrodes fixed to the moving sub-disk. A metal bellows is sealed between the moving end base and the moving disk to form a vacuum chamber together with the outer shell. The stationary electrode is fixed to the inner end face of the stationary electrode disk and is coupled to the moving electrode in the vacuum chamber. The moving electrode assembly is fixedly mounted with a metal conductive component, which is provided with a sliding contact finger. The moving end base is provided with a metal connecting cylinder along the axial direction. The sliding contact finger elastically abuts against the inner wall of the metal connecting cylinder by its own elastic force, and maintains sliding contact with the metal connecting cylinder throughout the entire stroke of the moving electrode assembly moving along the axial direction, so as to form a conductive path and a heat dissipation path in parallel with the metal bellows between the moving electrode assembly and the moving end base.

[0008] As a further improvement of the present invention, the metal conductive component is in the form of a ring structure, with a fixed end and a free end at its two axial ends, respectively. The diameter of the metal conductive component gradually increases from the fixed end to the free end. The fixed end is fixedly connected to the moving disk, and the sliding contact finger is disposed on the free end.

[0009] As a further improvement of the present invention, the fixed end is a fixed ring integrally formed on the metal conductive component, and the outer cylindrical surface of the moving disk is provided with an annular positioning step, and the fixed ring is fixedly fitted on the annular positioning step.

[0010] As a further improvement of the present invention, multiple sliding fingers are provided and are evenly distributed circumferentially along the free end of the metal conductive element.

[0011] As a further improvement of the present invention, the sliding finger includes an elastic cantilever and a contact portion, one end of the elastic cantilever is fixedly connected to the fixed end of the metal conductive element, and the contact portion is formed at the other end of the elastic cantilever.

[0012] As a further improvement of the present invention, the side of the contact portion facing the inner wall of the metal connecting cylinder is configured as an arc-shaped contact surface.

[0013] As a further improvement of the present invention, the metal conductive component is integrally stamped from a thin-walled elastic metal sheet, and its outer surface is plated with a highly conductive coating, which is a silver layer or a gold layer.

[0014] As a further improvement of the present invention, the axial height of the metal connecting cylinder is greater than the maximum axial movement distance of the moving electrode assembly, so that the sliding contact finger always remains in contact with the inner wall of the metal connecting cylinder throughout the entire axial movement of the moving electrode assembly.

[0015] As a further improvement of the present invention, the outer diameter of the metal bellows is smaller than the inner diameter of the metal conductive element, and the metal bellows is disposed in the internal cavity of the metal conductive element.

[0016] As a further improvement of the present invention, the high heat dissipation and high current variable vacuum capacitor also includes a guide sleeve, a pull rod, and a transmission mechanism. The guide sleeve is fixed to the moving end base, and the pull rod is fixedly connected to the moving sub-disc and slidably passes through the guide sleeve. The transmission mechanism is drivenly connected to the pull rod and is used to drive the moving electrode group to move axially through the pull rod under the drive of an external motor.

[0017] The beneficial effects of this invention are as follows: This invention provides a high-heat-dissipation, high-current variable vacuum capacitor. By adding a metal conductive component with sliding contacts between the moving electrode group and the moving end base, a conductive path and a heat dissipation path are formed in parallel with the metal bellows. This effectively solves the problems of insufficient current-carrying capacity and low heat dissipation efficiency caused by existing variable vacuum capacitors relying solely on the metal bellows path to transmit current and heat. The simultaneous operation of the two parallel paths significantly increases the total conductive area from the moving electrode group to the moving end base, effectively mitigating the adverse effects of the high-frequency skin effect on conductivity and greatly improving the high-current carrying capacity of the vacuum capacitor. At the same time, it significantly increases the total heat dissipation area, reduces the overall thermal resistance, and allows the Joule heat generated inside the vacuum capacitor to be discharged to the external environment more quickly and evenly. This significantly reduces the operating temperature of the vacuum capacitor, avoiding problems such as decreased insulation strength between electrodes, reduced withstand voltage, and capacitance temperature drift caused by high temperatures. This improves the working stability and reliability of the vacuum capacitor and reduces equipment costs and maintenance difficulty. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a cross-sectional view of the high heat dissipation, high current variable vacuum capacitor of the present invention in its maximum capacitance state. Figure 2 This is a cross-sectional view of the high heat dissipation, high current variable vacuum capacitor of the present invention in its minimum capacitance state. Figure 3 This is a perspective view of the metal conductive component in the high-heat-dissipation, high-current variable vacuum capacitor of the present invention.

[0020] Referring to the accompanying drawings, the following explanations are provided: 1. Insulating cylinder; 2. Moving end base; 21. Metal connecting cylinder; 3. Static electrode disk; 4. Moving electrode assembly; 41. Moving sub-disk; 411. Annular positioning step; 42. Moving electrode; 5. Metal bellows; 6. Static electrode; 7. Metal conductive component; 71. Sliding contact finger; 711. Elastic cantilever; 712. Contact part; 7121. Arc-shaped contact surface; 72. Fixing ring; 8. Guide sleeve; 9. Pull rod; 10. Rotating screw; 11. Positioning nut; 12. Sleeve; 13. Planar bearing; L, Maximum axial movement distance of the moving electrode assembly. Detailed Implementation

[0021] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0023] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The illustrations only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the shape, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0024] Additionally, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that practice can be carried out without these specific details.

[0025] The technical solutions provided by the various embodiments of this application are described below with reference to the accompanying drawings.

[0026] See Figures 1 to 3 The present invention provides a high heat dissipation and high current variable vacuum capacitor, comprising: a housing, a moving electrode group 4, a metal bellows 5, and a stationary electrode 6.

[0027] The outer casing contains a vacuum chamber and includes an insulating cylinder 1, a moving end base 2, and a stationary electrode disk 3. The moving end base 2 and the stationary electrode disk 3 are respectively sealed and fixed to the axial ends of the insulating cylinder 1. In this embodiment, the moving end base 2 is fixed to the upper end of the insulating cylinder 1, and the stationary electrode disk 3 is fixed to the lower end of the insulating cylinder 1.

[0028] Furthermore, the moving electrode assembly 4 is disposed within the outer casing. The moving electrode assembly 4 includes a moving disk 41 and a moving electrode 42. The moving disk 41 is arranged horizontally and is axially opposite to the moving end base 2. The moving electrode 42 is fixed to the bottom surface of the moving disk 41. A metal bellows 5 is sealed between the inner end face of the moving end base 2 and the top surface of the moving disk 41, thereby forming a vacuum chamber by the moving disk 41, the metal bellows 5, and the outer casing.

[0029] In this invention, both the metal bellows 5 and the moving end base 2 are conductive components, and the moving end base 2 serves as the electrical connection terminal for the moving electrode 42 to be connected to the working circuit.

[0030] Furthermore, the stationary electrode 6 is fixed to the inner end face of the stationary electrode disk 3, which is also a conductive component, serving as the electrical connection terminal for the stationary electrode 6 to access the working circuit. The stationary electrode 6 and the moving electrode 42 are coupled together in the vacuum chamber. The moving electrode assembly 4 can move axially within the outer shell to change the coupling length between the moving electrode 42 and the stationary electrode 6, thereby adjusting the capacitance of the vacuum capacitor.

[0031] It is understood that the axial direction mentioned in this article refers to the direction of the central axis of the vacuum capacitor.

[0032] As an important improvement of the present invention, a metal conductive element 7 is fixedly installed on the moving electrode assembly 4. The metal conductive element 7 is provided with a sliding contact finger 71. A metal connecting cylinder 21 is provided along the axial direction of the moving end base 2. The sliding contact finger 71 elastically abuts against the inner wall of the metal connecting cylinder 21 by its own elastic force, and always maintains sliding contact with the metal connecting cylinder 21 throughout the entire stroke of the moving electrode assembly 4 moving along the axial direction, so as to form a conductive path and a heat dissipation path in parallel with the metal bellows 5 between the moving electrode assembly 4 and the moving end base 2.

[0033] The two parallel conductive paths are as follows: the first is the inherent metal bellows conductive path, where current is conducted from the moving end base 2 through the metal bellows 5 to the moving electrode group 4; the second is the newly added metal conductive element conductive path, where current is conducted from the moving end base 2 sequentially through the metal connecting cylinder 21 and the metal conductive element 7 to the moving electrode group 4. The parallel operation of these two conductive paths significantly increases the total conductive area from the moving electrode group 4 to the moving end base 2.

[0034] The two parallel heat dissipation paths are as follows: the first is the inherent metal bellows heat dissipation path, where the Joule heat generated by the moving electrode assembly 4 is conducted through the metal bellows 5 to the moving end base 2 and then dissipated to the external environment; the second is the heat dissipation path of the newly added metal conductive component, where the Joule heat generated by the moving electrode assembly 4 is conducted through the metal conductive component 7 to the metal connecting cylinder 21 and the moving end base 2 and then dissipated to the external environment. The two heat dissipation paths work simultaneously, significantly increasing the total heat dissipation area.

[0035] Therefore, this invention, by adding a metal conductive element 7 with a sliding contact finger 71 between the moving electrode group 4 and the moving end base 2, forms a conductive and heat dissipation path connected in parallel with the metal bellows 5. This effectively solves the problems of insufficient current carrying capacity and low heat dissipation efficiency in existing variable vacuum capacitors that rely solely on the metal bellows 5 for current and heat transmission. The simultaneous operation of the two parallel paths significantly increases the total conductive area from the moving electrode group 4 to the moving end base 2, effectively mitigating the adverse effects of the high-frequency skin effect on conductivity and greatly improving the high-current carrying capacity of the vacuum capacitor. Simultaneously, it significantly increases the total heat dissipation area, reduces the overall thermal resistance, and allows the Joule heat generated inside the vacuum capacitor to be dissipated to the external environment more quickly and evenly, significantly reducing the operating temperature of the vacuum capacitor. This avoids problems such as decreased inter-electrode insulation strength, reduced withstand voltage, and capacitance temperature drift caused by high temperatures, thus improving the working stability and reliability of the vacuum capacitor.

[0036] In addition, this structure eliminates the need for an additional circulating water cooling system and increases the diameter of the metal bellows 5, thus reducing equipment costs and maintenance difficulty.

[0037] In this invention, the insulating cylinder 1 can be, but is not limited to, circular, and can be made of ceramic material with high insulation performance. It can withstand the strong electric field under high-frequency, high-voltage working conditions, effectively preventing leakage and ensuring the safe and stable operation of the vacuum capacitor under rated voltage. The metal connecting cylinder 21 can be integrally formed from the moving end base 2 extending towards the insulating cylinder 1, or it can be a separate structure from the moving end base 2, with the moving end base 2 welded to the upper end of the insulating cylinder 1 via the metal connecting cylinder 21. The stationary electrode disk 3 extends integrally towards the insulating cylinder 1 with a welding ring, and the stationary electrode disk 3 is welded to the lower end of the insulating cylinder 1 via the welding ring.

[0038] Both the moving electrode 42 and the stationary electrode 6 employ conventional electrode structures. In this embodiment, both the moving electrode 42 and the stationary electrode 6 are composed of multiple electrode rings of different diameters coaxially spaced together. The electrode rings of the moving electrode 42 and the stationary electrode 6 are arranged alternately from the inside to the outside, and the spacing between adjacent electrode rings is the same. Simultaneously, the electrode rings of the moving electrode 42 and the stationary electrode 6 extend at least partially into each other, and the overlapping portion constitutes the coupling length between the moving electrode 42 and the stationary electrode 6. By adjusting the axial position of the moving electrode 42, the coupling length between the moving electrode 42 and the stationary electrode 6 is changed, thereby achieving the capacitance adjustment of the vacuum capacitor. Of course, in other embodiments of the present invention, both the moving electrode 42 and the stationary electrode 6 may also employ conventional spiral electrodes.

[0039] See Figure 1 and Figure 3The metal conductive component 7 has an overall annular structure, and the outer diameter of the metal bellows 5 is smaller than the inner diameter of the metal conductive component 7. The metal bellows 5 is disposed in the internal cavity of the metal conductive component 7. Since the metal conductive component 7 undertakes part of the conductivity and heat dissipation functions, the metal bellows 5 does not need to be designed with a large diameter. The diameter of the metal bellows 5 can be designed to be smaller, thereby reducing the stress area of ​​the metal bellows 5 under atmospheric pressure, thus significantly reducing the adjustment torque of the vacuum capacitor.

[0040] Furthermore, the axial ends of the metal conductive element 7 are a fixed end and a free end, respectively, with the free end located above the fixed end. The diameter of the metal conductive element 7 gradually increases from the fixed end to the free end. The fixed end is fixedly connected to the moving disk 41, and the sliding contact finger 71 is disposed on the free end. By designing the metal conductive element 7 as an annular structure with a diameter that gradually increases from the fixed end to the free end, the metal conductive element 7 naturally forms an umbrella-shaped elastic structure. It can rely on the radial elastic force generated by its own structure to keep the sliding contact finger 71 in close contact with the inner wall of the metal connecting cylinder 21, and the contact pressure is stable, ensuring conductivity and heat dissipation performance throughout the entire stroke.

[0041] The fixed end is a fixing ring 72 integrally formed on the metal conductive component 7. The outer cylindrical surface of the moving disk 41 has an annular groove near the top, forming an annular positioning step 411. The fixing ring 72 is fixedly fitted onto the annular positioning step 411, which can achieve precise positioning and reliable fixation of the metal conductive component 7, and ensure the coaxiality of the metal conductive component 7 and the moving disk 41. This avoids the problem of unreliable contact between the sliding contact finger 71 and the inner wall of the metal connecting cylinder 21 due to installation deviation. The fixing ring 72 and the moving disk 41 can be fixed by, but is not limited to, brazing or fusion welding.

[0042] As a further improvement of the present invention, multiple sliding fingers 71 are provided, and the multiple sliding fingers 71 are evenly distributed circumferentially along the free end of the metal conductive member 7, so that current and heat can be evenly conducted to the metal connecting cylinder 21 through each sliding finger 71. At the same time, the circumferentially evenly distributed sliding fingers 71 can make the metal conductive member 7 as a whole balanced in force, reducing the vibration and sway of the metal conductive member 7 during the axial movement of the moving electrode group 4, and improving the stability of the movement.

[0043] like Figure 3 As shown, the sliding contact 71 includes an elastic cantilever 711 and a contact portion 712. The elastic cantilever 711 is a thin-walled sheet-like structure with a certain width, one end of which is fixedly connected to the fixing ring 72 of the metal conductive component 7, and the contact portion 712 is formed at the other end of the elastic cantilever 711. The elastic cantilever 711 can provide a stable and durable elastic contact force, ensuring that the sliding contact 71 and the inner wall of the metal connecting cylinder 21 remain in close contact during the axial movement of the moving electrode assembly 4.

[0044] It is worth mentioning that the side of the contact portion 712 facing the inner wall of the metal connecting cylinder 21 is set as an arc-shaped contact surface 7121. The arc-shaped contact surface 7121 is used to slide in contact with the inner wall of the metal connecting cylinder 21, which can significantly reduce the sliding friction between the sliding contact finger 71 and the inner wall of the metal connecting cylinder 21, reduce wear, and extend the mechanical service life of the metal conductive component 7. At the same time, the arc-shaped contact surface 7121 can form a stable line contact or a small area surface contact with the inner wall of the metal connecting cylinder 21, ensuring conductivity and heat dissipation efficiency, and can avoid scratching the inner wall of the metal connecting cylinder 21, maintaining good contact performance for a long time.

[0045] Preferably, the metal conductive component 7 is integrally stamped from a thin-walled elastic metal sheet, such as tin bronze or beryllium bronze, which are highly elastic and have self-lubricating properties. Simultaneously, a highly conductive coating, either silver or gold, is plated on the outer surface of the metal conductive component 7, which significantly reduces the surface resistance of the metal conductive component 7 and further improves the transmission efficiency of high-frequency current.

[0046] In addition, the high heat dissipation and high current variable vacuum capacitor of the present invention also includes a guide sleeve 8, a pull rod 9 and a transmission mechanism. The moving end base 2 has a mounting hole in the middle. The guide sleeve 8 is fixed in the mounting hole of the moving end base 2 and extends axially into the outer shell. The pull rod 9 is fixedly connected to the moving sub-disk 41 and slides through the guide sleeve 8. The transmission mechanism is connected to the pull rod 9 and is used to drive the moving electrode group 4 to move axially through the pull rod 9 under the drive of an external motor.

[0047] The transmission mechanism adopts a conventional structure, including a rotating screw 10 and a positioning nut 11. A sleeve 12 is fixed to the upper end of the guide sleeve 8, and the positioning nut 11 is fixedly installed on the upper end of the pull rod 9 and housed in the sleeve 12. The rotating screw 10 is rotatably installed on the sleeve 12 through a plane bearing 13 and is threadedly connected to the positioning nut 11. The rotating screw 10 and the positioning nut 11 work together to convert the rotational motion of the external motor into the linear motion of the moving electrode group 4, thereby achieving precise and continuous adjustment of the capacitance value.

[0048] like Figure 1 As shown, when the frustum on the positioning nut 11 stops at the top of the guide sleeve 8, the vacuum capacitor is at its maximum capacitance. When the external motor drives the rotating screw 10 to rotate counterclockwise, the positioning nut 11 and the moving electrode group 4 move upward with the rotation of the rotating screw 10, and the coupling length between the moving electrode 42 and the stationary electrode 6 decreases until the frustum on the positioning nut 11 stops at the inner top wall of the sleeve 12, at which point the vacuum capacitor is at its minimum capacitance (e.g., ...). Figure 2 (As shown).

[0049] The maximum axial movement distance of the moving electrode group 4 is L, and the maximum axial movement distance L of the moving electrode group 4 is less than the axial height of the metal connecting cylinder 21, so that the sliding contact finger 71 always keeps in contact with the inner wall of the metal connecting cylinder 21 throughout the entire stroke of the axial movement of the moving electrode group 4, and there will be no problem of interruption of the conductive path caused by the sliding contact finger 71 disengaging from the metal connecting cylinder 21, thus ensuring that the vacuum capacitor can work stably and reliably throughout the entire capacitance adjustment range.

[0050] The same or similar parts between the various embodiments in this specification can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments.

[0051] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A high-heat-dissipation, high-current variable vacuum capacitor, comprising: The outer casing includes an insulating cylinder (1) and a moving end base (2) and a stationary electrode disk (3) respectively sealed and fixed at both ends of the axial direction of the insulating cylinder (1). The moving electrode assembly (4) is disposed in the housing and can move axially to adjust the capacitance of the vacuum capacitor. The moving electrode assembly (4) includes a moving sub-disk (41) and a moving electrode (42) fixed to the moving sub-disk (41). A metal bellows (5) is sealed between the moving end base (2) and the moving sub-disc (41) to form a vacuum chamber together with the outer shell. The stationary electrode (6) is fixed to the inner end face of the stationary electrode disk (3) and is coupled to the moving electrode (42) in the vacuum chamber. The feature is that a metal conductive element (7) is fixedly installed on the moving electrode group (4), the metal conductive element (7) is provided with a sliding contact finger (71), the moving end base (2) is provided with a metal connecting cylinder (21) along the axial direction, the sliding contact finger (71) elastically abuts against the inner wall of the metal connecting cylinder (21) by its own elastic force, and always maintains sliding contact with the metal connecting cylinder (21) throughout the entire stroke of the moving electrode group (4) moving along the axial direction, so as to form a conductive path and heat dissipation path in parallel with the metal bellows (5) between the moving electrode group (4) and the moving end base (2).

2. The high-heat dissipation, high-current variable vacuum capacitor according to claim 1, characterized in that, The metal conductive element (7) has an overall ring structure with a fixed end and a free end at its two axial ends. The diameter of the metal conductive element (7) gradually increases from the fixed end to the free end. The fixed end is fixedly connected to the moving disk (41), and the sliding finger (71) is disposed on the free end.

3. The high-heat dissipation, high-current variable vacuum capacitor according to claim 2, characterized in that, The fixed end is a fixed ring (72) integrally formed on the metal conductive part (7). The outer cylindrical surface of the moving disk (41) is provided with an annular positioning step (411). The fixed ring (72) is fixedly fitted on the annular positioning step (411).

4. The high-heat dissipation, high-current variable vacuum capacitor according to claim 2, characterized in that, Multiple sliding fingers (71) are provided and are evenly distributed circumferentially along the free end of the metal conductive element (7).

5. The high-heat dissipation, high-current variable vacuum capacitor according to claim 4, characterized in that, The sliding finger (71) includes an elastic cantilever (711) and a contact portion (712). One end of the elastic cantilever (711) is fixedly connected to the fixed end of the metal conductive element (7), and the contact portion (712) is formed at the other end of the elastic cantilever (711).

6. The high-heat dissipation, high-current variable vacuum capacitor according to claim 5, characterized in that, The side of the contact portion (712) facing the inner wall of the metal connecting cylinder (21) is provided as an arc-shaped contact surface (7121).

7. The high-heat dissipation, high-current variable vacuum capacitor according to claim 1, characterized in that, The metal conductive component (7) is integrally stamped from a thin-walled elastic metal sheet, and its outer surface is plated with a highly conductive coating, which is a silver layer or a gold layer.

8. The high-heat dissipation, high-current variable vacuum capacitor according to claim 1, characterized in that, The axial height of the metal connecting cylinder (21) is greater than the maximum axial movement distance of the moving electrode group (4) so ​​that the sliding contact finger (71) always keeps in contact with the inner wall of the metal connecting cylinder (21) throughout the entire axial movement of the moving electrode group (4).

9. The high-heat dissipation, high-current variable vacuum capacitor according to claim 1, characterized in that, The outer diameter of the metal bellows (5) is smaller than the inner diameter of the metal conductive element (7), and the metal bellows (5) is disposed in the internal cavity of the metal conductive element (7).

10. The high-heat dissipation, high-current variable vacuum capacitor according to claim 1, characterized in that, It also includes a guide sleeve (8), a pull rod (9) and a transmission mechanism. The guide sleeve (8) is fixed to the moving end base (2), and the pull rod (9) is fixedly connected to the moving sub-disc (41) and slides through the guide sleeve (8). The transmission mechanism is connected to the pull rod (9) and is used to drive the moving electrode group (4) to move axially through the pull rod (9) under the drive of an external motor.

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