A gas path electrical insulator integrated with a hollow cathode

Abstract

The application relates to the technical field of plasma propulsion, in particular to a gas path electric insulator integrated with a hollow cathode, which comprises a gas inlet interface, an insulating chamber and a gas outlet interface, wherein: one side of the insulating chamber is connected with the gas inlet interface and is provided with a gas inlet; the other side of the insulating chamber is connected with the gas outlet interface and is provided with a gas outlet; the gas inlet interface is connected with a gas supply pipeline, and the gas outlet interface is connected with the hollow cathode; the inside of the insulating chamber is provided with a ceramic insulating structure, and the outside is provided with a metal shielding cover. The application has the advantages of simple structure, small volume and light mass, the internal components of the gas path electric insulator are specially designed, the distance between the inlet and outlet electrodes is increased under the same axial length, the insulating property is improved, the probability of sputtering deposition on the surface of the ceramic insulating structure is reduced, the high-performance gas path electric insulation can be realized while the hollow cathode is integrated, and the integration degree of the product is improved.

Description

Technical Field

[0001] This application relates to the field of plasma propulsion technology, and more specifically, to a gas-circuit electrical insulator integrated with a hollow cathode. Background Technology

[0002] When the ion thruster is working, the hollow cathode is under high voltage, which can reach thousands of volts. Gas circuit electrical insulators must be installed on its gas supply line to suppress low-pressure discharge, so as to ensure that the electric thruster can work normally and ensure overall safety.

[0003] The existing products have separate designs for the gas-insulated circuit and the hollow cathode. The gas-insulated circuit requires the design of a gas interface with the hollow cathode as well as a fixed installation interface. In addition, the gas flow path is linear and the axial dimension is large, which is not conducive to integrated design. Summary of the Invention

[0004] The main objective of this application is to provide a gas-circuit electrical insulator that is integrated with a hollow cathode. This increases the distance between the inlet and outlet electrodes, improves insulation, and enables high-performance gas-circuit electrical insulation while being integrated with a hollow cathode, thereby increasing product integration and reducing size.

[0005] To achieve the above objectives, this application provides a gas-circuit electrical insulator integrated with a hollow cathode, comprising an air inlet, an insulating chamber, and an air outlet, wherein: one side of the insulating chamber is connected to the air inlet and is provided with an air inlet; the other side of the insulating chamber is connected to the air outlet and is provided with an air outlet; the air inlet is connected to an air supply pipeline, and the air outlet is connected to the hollow cathode; the interior of the insulating chamber is provided with a ceramic insulating structure, and the exterior is provided with a metal shield.

[0006] Furthermore, the ceramic insulation structure includes an inner ceramic insulation structure and an outer ceramic insulation structure. One end of the outer ceramic insulation structure is connected to the air inlet and the other end is connected to the air outlet. The inner ceramic insulation structure is located inside the insulation chamber.

[0007] Furthermore, the inner and outer ceramic insulation structures form an S-shaped gas flow channel inside the insulation chamber.

[0008] Furthermore, vent holes are provided along the circumference of the inner ceramic insulation structure, and the outer surface of the outer ceramic insulation structure is configured as a U-shaped groove structure.

[0009] Furthermore, the S-shaped gas flow channel formed inside the insulating chamber is filled with alumina ceramic particles.

[0010] Furthermore, the metal shielding cover includes an inner metal shielding cover and an outer metal shielding cover, and both the inner and outer metal shielding covers have a bending structure in the middle.

[0011] Furthermore, one end of the inner metal shield is fixedly connected to the air intake interface.

[0012] Furthermore, one end of the outer metal shield is fixedly connected to the air outlet.

[0013] Furthermore, all air vents are equipped with stainless steel screens.

[0014] Furthermore, the ceramic insulation structure is made of alumina ceramic, and the metal shield is made of thin-walled Kovar alloy material 4J29.

[0015] The present invention provides a gas-circuit electrical insulator integrated with a hollow cathode, which has the following beneficial effects:

[0016] This application features a simple structure, small size, and light weight. The internal components of the gas-insulated circuit are specially designed. By setting inner and outer ceramic insulation structures, the working gas can flow along an S-shaped channel inside the insulation chamber. This increases the distance between the inlet and outlet electrodes for the same axial length, improving insulation. The use of inner and outer metal shields reduces the probability of sputtering deposits on the ceramic insulation surface. Furthermore, a connection interface with the hollow cathode is designed, enabling high-performance gas-insulated circuit insulation while seamlessly integrating with the hollow cathode, thus improving the product's integration level. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of this application are used to explain the application and do not constitute an undue limitation of the application. In the drawings:

[0018] Figure 1 This is a schematic diagram of a gas-insulated circuit integrated with a hollow cathode, provided according to an embodiment of this application;

[0019] Figure 2 This is a cross-sectional view of a gas-insulated electrical circuit integrated with a hollow cathode, according to an embodiment of this application.

[0020] Figure 3 This is a schematic diagram of the ceramic insulation structure inside the gas-circuit electrical insulator integrated with the hollow cathode, according to an embodiment of this application.

[0021] Figure 4 This is a schematic diagram of the external ceramic insulation structure of the gas-circuit electrical insulator integrated with the hollow cathode, according to an embodiment of this application.

[0022] In the diagram: 1-Inlet port, 2-Outer ceramic insulation structure, 3-Inner ceramic insulation structure, 4-Inner metal shield, 5-Outer metal shield, 6-Stainless steel screen, 7-Outlet port, 8-Ceramic particles, 9-Hollow cathode, 10-Inlet port. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0024] like Figure 1 As shown, this application provides a gas-circuit electrical insulator integrated with a hollow cathode, including an air inlet 1, an insulating chamber, and an air outlet 7, wherein: one side of the insulating chamber is connected to the air inlet 1 and is provided with an air inlet 10; the other side of the insulating chamber is connected to the air outlet 7 and is provided with an air outlet; the air inlet 1 is connected to an air supply pipeline, and the air outlet 7 is connected to the hollow cathode 9; the interior of the insulating chamber is provided with a ceramic insulating structure, and the exterior is provided with a metal shield.

[0025] Specifically, the gas-electric insulator integrated with the hollow cathode provided in this embodiment is installed between the gas supply pipeline and the hollow cathode 9 to ensure the insulation of the gas entering the hollow cathode 9. The working gas in the gas supply device enters the gas inlet 1 along the gas supply pipeline, enters the insulation chamber through the gas inlet 10 on the gas inlet 1, flows in the insulation chamber, and after being insulated by the ceramic insulating material, enters the hollow cathode 9 through the gas outlet to ensure the normal operation of the subsequent thrust device.

[0026] Furthermore, the ceramic insulation structure includes an inner ceramic insulation structure 3 and an outer ceramic insulation structure 2. One end of the outer ceramic insulation structure 2 is connected to the air inlet 1, and the other end is connected to the air outlet 7. The inner ceramic insulation structure 3 is disposed inside the insulation chamber. Both the inner ceramic insulation structure 3 and the outer ceramic insulation structure 2 are annular cylindrical structures. The outer ceramic insulation structure 2 is fixed between the air inlet 1 and the air outlet 7. After the inner ceramic insulation structure 3 and the outer ceramic insulation structure 2 are assembled, an insulation cavity is formed in the middle for the flow of the working gas.

[0027] Furthermore, such as Figure 3-4As shown, the inner ceramic insulation structure 3 and the outer ceramic insulation structure 2 form an S-shaped gas flow channel inside the insulation chamber. In this embodiment, after the inner ceramic insulation structure 3 and the outer ceramic insulation structure 2 are brazed and fixed, an S-shaped gas flow channel is formed inside the insulation chamber. The working gas flows up and down along the S-shaped gas channel, and finally converges through the outlet hole and enters the hollow cathode 9 through the outlet. By using the inner and outer ceramic insulation structures to design an S-shaped gas channel, the distance between the inlet 10 and the outlet hollow cathode 9 is increased under the same axial length, so that the working gas flows in the insulation chamber for a longer time, thus improving the insulation performance.

[0028] Furthermore, vent holes are provided circumferentially along the inner ceramic insulation structure 3, and the outer surface of the outer ceramic insulation structure 2 is configured with a U-shaped groove structure. The inner ceramic insulation structure 3 is fixedly connected to the vent interface 7. At the connection between the inner ceramic insulation structure 3 and the vent interface 7, a ring of vent holes is provided circumferentially, with a preferred diameter of 2 mm, which can increase the uniformity of gas flow. The outer surface of the outer ceramic insulation structure 2 is designed with a U-shaped groove distributed in a ring, with a preferred groove width of 0.3 mm, which reduces the risk of insulation degradation caused by ion sputtering deposits on the surface.

[0029] Furthermore, the S-shaped gas flow channel formed inside the insulating chamber is filled with alumina ceramic particles 8. The alumina ceramic particles 8 are filled inside primarily to insulate the flowing gas, and the diameter of the alumina ceramic particles 8 is preferably 400 μm.

[0030] Furthermore, the metal shielding includes an inner metal shielding 4 and an outer metal shielding 5, both of which have a bent structure in the middle. The metal shielding is configured as an inner and outer structure, with the inner and outer metal shielding 5 designed in a labyrinthine pattern to reduce the path of sputtered material contacting the surface of the outer ceramic insulating structure 2. The bent shape in the middle of the metal shielding enhances structural strength while reducing the probability of sputtered material depositing on the ceramic structure surface.

[0031] Furthermore, one end of the inner metal shield 4 is fixedly connected to the air intake port 1. The inner metal shield 4 is configured as an annular cylinder, with one end fixedly connected to the air intake port 1, and is entirely fitted over the outer ceramic insulation structure 2.

[0032] Furthermore, one end of the outer metal shield 5 is fixedly connected to the air outlet 7. The outer metal shield 5 is also configured as an annular cylinder, with one end fixedly connected to the air outlet 7, and is fitted over the inner metal shield 4.

[0033] Furthermore, each vent is equipped with a stainless steel screen 6. The vents circumferentially distributed within the inner ceramic insulation structure 3 are all equipped with stainless steel screens 6, with mesh diameters less than 400 μm, to prevent ceramic particles 8 from entering the hollow cathode 9.

[0034] Furthermore, the ceramic insulation structure is made of alumina ceramic, and the metal shield is made of thin-walled Kovar alloy 4J29. The ceramic insulation structure is mainly used to insulate the working gas, and the preferred material is alumina ceramic. The metal shield is mainly used to block external sputtered deposits, and the preferred material is Kovar alloy 4J29.

[0035] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A gas path electrical isolator integrated with a hollow cathode, characterized in that, The air inlet interface, the insulation chamber and the air outlet interface are included, wherein: One side of the insulation chamber is connected with the air inlet interface and is provided with an air inlet; The other side of the insulation chamber is connected with the air outlet interface and is provided with an air outlet; The air inlet interface is connected with a gas supply pipeline, and the air outlet interface is connected with a hollow cathode; The inside of the insulation chamber is provided with a ceramic insulation structure, and the outside is provided with a metal shielding cover; The ceramic insulation structure includes an inner ceramic insulation structure and an outer ceramic insulation structure, one end of the outer ceramic insulation structure is connected with the air inlet interface, the other end is connected with the air outlet interface, and the inner ceramic insulation structure is arranged inside the insulation chamber; The inner ceramic insulation structure and the outer ceramic insulation structure form an S-shaped gas flow channel inside the insulation chamber; Air outlet holes are arranged along the circumference of the inner ceramic insulation structure, and the outer surface of the outer ceramic insulation structure is arranged in a U-shaped groove structure; The metal shielding cover includes an inner metal shielding cover and an outer metal shielding cover, and the middle parts of the inner metal shielding cover and the outer metal shielding cover are both provided with a bending structure.

2. The gas-line electrical isolator integrated with a hollow cathode as claimed in claim 1, wherein, The S-shaped gas flow channel formed inside the insulation chamber is filled with alumina ceramic particles.

3. The gas circuit electrical isolator integrated with a hollow cathode as claimed in claim 1, wherein, One end of the inner metal shielding cover is fixedly connected with the air inlet interface.

4. The gas-line electrical isolator integrated with a hollow cathode as claimed in claim 3, wherein, One end of the outer metal shielding cover is fixedly connected with the air outlet interface.

5. The gas-line electrical isolator integrated with a hollow cathode as defined in claim 1, wherein, The air outlet holes are all provided with stainless steel screens.

6. The gas-line electrical isolator integrated with a hollow cathode as claimed in claim 1, wherein, The material of the ceramic insulation structure is alumina ceramic, and the material of the metal shielding cover is thin-walled Kovar alloy material 4J29.

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