Spacecraft space conductive slip ring and preparation method of high insulation performance brush thereof

Abstract

The application discloses a spacecraft space conductive slip ring and a preparation method of a high-insulation performance brush thereof, and aims to enhance the stability and reliability of the brush in an extreme space environment. A double-layer insulation film is prepared on the surface of a brush main body part and a welding point of the brush and a wire by adopting a PVD gas phase deposition technology, an inner layer film is doped with high-thermal-conductivity and flexible comonomers and fillers, good insulation performance and tensile flexibility of the film layer are given, and the contact force and transmission efficiency after the brush is assembled are ensured. An outer layer film is doped with high-dielectric-constant and environment-corrosion-resistant comonomers and fillers, and the insulation strength and environmental adaptability are improved. The prepared double-layer structure brush insulation film layer has excellent electric insulation resistance, high and low temperature resistance, corrosion resistance and weather resistance. Active molecules are uniformly deposited to form a dense film layer, and stress concentration and discharge hidden dangers are avoided. Meanwhile, a key contact area of the film layer is removed by adopting a laser beam or an ion beam, and the brush conduction is ensured and the protection function is maximally reserved.

Description

Technical Field

[0001] This invention belongs to the field of spacecraft electrical transmission and conductive slip ring technology, and relates to improving the insulation performance of space conductive slip ring brushes used in spacecraft. Specifically, it is a method for preparing a space conductive slip ring and its high-insulation brush. By using a polymer insulating material and PVD vapor deposition, a double-layer insulating coating is applied to the brush, which effectively improves the insulation protection of the brush surface, enhances its stability and reliability in the space environment, and thus extends the service life of key spacecraft components. Background Technology

[0002] A conductive slip ring is a precision electrical transmission device that transmits signals or power through two relatively rotating mechanisms. It is widely used in various spacecraft systems, such as solar panel drive mechanisms (SADA), control moment gyroscopes (CMG), laser communication pointing mechanisms (CPA), and space scanning mechanisms. Because its working principle is based on frictional transmission, wear debris is inevitably generated during the friction between the brushes and the conductive ring. This charged wear debris moves unpredictably under the combined effects of vacuum, weightlessness, and electromagnetic fields, causing localized electric field enhancement and potentially leading to short circuits between adjacent conductors. In severe cases, it can cause open circuits, resulting in the failure of the spacecraft's power and control systems. To improve transmission efficiency, conductive slip rings typically employ a multi-loop design, with brushes in adjacent loops arranged in parallel with very small spacing. Therefore, adjacent brushes are highly susceptible to the influence of charged wear debris, leading to short circuits and consequently affecting the spacecraft's usability and lifespan.

[0003] Furthermore, due to the specific needs of spacecraft, many conductive slip rings need to transmit signals in different frequency bands, requiring high transmission stability. However, the spacing between these slip rings is usually small, and the brushes are close together, making them more susceptible to the influence of charged abrasive debris during space transmission, leading to unstable signal transmission between rings. Simultaneously, multiple brushes may interfere with each other during signal transmission, causing signal instability. Secondly, the SADA device is installed at the interface between the satellite body and outer space, directly facing the space plasma environment, making it highly vulnerable to charge and discharge interference. Charge easily accumulates at the weld points between brushes and wires, and at brush tips. Once the charge reaches a certain threshold, discharge may occur, and the resulting electrostatic discharge interference can cause malfunctions in other satellite equipment. Repeated discharges may cause the conductive slip rings to break down, leading to abnormal power or signal transmission.

[0004] Existing insulation treatments for conductive slip ring brushes typically involve using insulating heat-shrink tubing. However, this method has several drawbacks, including: significant limitations on brushes with small spacing; operational difficulties; and the impact of the heat-shrink process on the material's elastic modulus and strength. Furthermore, the heat-shrink tubing cannot simultaneously cover the brush body, tip, and brush-lead connection. Incomplete adhesion between the heat-shrink tubing and the brush allows charged particles to enter through the gaps, leading to discharge. Additionally, if the heat-shrink tubing detaches in a vacuum, it becomes a floating object, accumulating a large amount of charge and increasing the probability of discharge breakdown. The relatively thick heat-shrink tubing results in poor elasticity after thermoforming, affecting the contact pressure between the brush and the conductive ring. Finally, the heat-shrink tubing affects brush angle shaping and contact pressure control; for example, the contact points of disc slip ring brushes are curved, making heat shrinking the tubing difficult after shaping.

[0005] In summary, improving the insulation performance of space conductive slip ring brushes is of great significance for ensuring the reliable operation of spacecraft energy and control systems, extending the service life of conductive slip rings, ensuring the stability of signal transmission, and reducing the risk of electrostatic discharge. However, existing brush surface insulation treatment technologies have many limitations. Therefore, it is urgent to develop a new method that can effectively improve the insulation performance of brushes, ensuring reliable contact between the brush and the conductive ring, preventing electrostatic discharge caused by charged wear debris deposition and charge accumulation, and enabling long-term reliable use in a vacuum environment. This is a technical problem that urgently needs to be solved. Summary of the Invention

[0006] (I) Purpose of the Invention

[0007] To address the shortcomings and deficiencies of existing conductive slip ring brushes, such as insufficient insulation performance, and to solve at least one of the aforementioned and other technical problems in the prior art, the present invention aims to provide a method for preparing a spacecraft space conductive slip ring and its high-insulation brush. This method involves using a polymer insulating material to perform PVD vapor deposition on the surface of the slip ring brush, forming inner and outer insulating films with uniform thickness, good adhesion, strong toughness, and high dielectric strength. This achieves comprehensive insulation protection for the brush body, avoids the influence of charged abrasive debris, improves the insulation performance of the brush, reduces the risk of discharge in the space environment, and extends the service life of the conductive slip ring.

[0008] (II) Technical Solution

[0009] To achieve the objective of this invention and solve its technical problems, the present invention adopts the following technical solution:

[0010] The first objective of this invention is to provide a spacecraft space conductive slip ring structure to improve the insulation performance of the brush and ensure a stable electrical connection between the brush and the conductive ring in extreme space environments such as vacuum, strong radiation, and extreme temperature changes. It is suitable for signal or power transmission in devices such as solar panel drive mechanisms, control torque gyroscopes, laser communication pointing mechanisms, and space scanning mechanisms. It includes at least a conductive ring and a brush assembly, characterized by:

[0011] An insulating film layer is formed on the surface of the main body of each brush and the solder joint between each brush and the wire in the brush assembly. The insulating film layer has a double-layer structure, using a high-molecular insulating material, p-xylene polymer, and is formed on the surface of the main body of the brush and the solder joint between the brush and the wire through a PVD vapor deposition process. It includes an inner insulating film and an outer insulating film.

[0012] The inner insulating film forms the insulating substrate for the main body of the brush and the solder joint surface between the brush and the wire. The polymer insulating material used in the inner insulating film is doped with high thermal conductivity and flexible copolymer monomers and / or has high thermal conductivity and high elongation fillers to improve the thermal conductivity and tensile properties of the inner insulating film. In the PVD vapor deposition process, the deposition rate is reduced to ensure the density and uniformity of the film layer, and the substrate temperature is controlled during the deposition process to reduce the thermal stress and dimensional changes of the material during the deposition process and ensure the mechanical stability of the film layer.

[0013] The outer insulating film covers the outer surface of the inner insulating film. The polymer insulating material used in the outer insulating film is doped with polar copolymer monomers with high dielectric constant and environmental corrosion resistance and / or has high dielectric constant and weather-resistant fillers added to improve the dielectric properties and environmental adaptability of the outer insulating film. In the PVD vapor deposition process, the deposition rate and vacuum degree are appropriately increased to ensure the uniformity and adhesion of the film layer. By controlling the substrate temperature and ion implantation during the deposition process, appropriate defect states are introduced into the film layer to optimize the charge carrier trapping and transport characteristics.

[0014] The second objective of this invention is to provide a method for preparing a high-insulation brush in a spacecraft space conductive slip ring, characterized in that the method mainly includes the following steps:

[0015] SS1. Brush Surface Preparation:

[0016] Chemical cleaning and / or ion beam polishing pretreatment is performed on the active metal surfaces of the brush body and the solder joints between the brush and the wire in the conductive slip ring of the spacecraft to remove surface contaminants, microparticles and / or surface oxides, ensuring the cleanliness and activity of the brush body and the solder joints between the brush and the wire.

[0017] SS2. Preparation of the inner insulating film:

[0018] Using PVD vapor deposition, by controlling the proportion of reactive gases, total pressure, ion energy and / or substrate temperature parameters, and by reducing the deposition rate, a layer of polymer insulating material inner insulating film is selectively deposited on the metal active surface of the brush body and the solder joint between the brush and the wire as an insulating substrate. The polymer insulating material is doped with high thermal conductivity and flexible comonomers and / or has high thermal conductivity and high elongation fillers added.

[0019] SS3. Preparation of the outer insulating film:

[0020] By employing PVD vapor deposition, a polymer insulating material outer insulating film is deposited on the outer surface of the inner insulating film by appropriately increasing the deposition rate and vacuum degree and controlling the substrate temperature during the deposition process. The polymer insulating material of this film is doped with polar copolymers with high dielectric constant and environmental corrosion resistance and / or filled with fillers with high dielectric constant and weather resistance. Furthermore, by controlling the energy and dosage of implanted ions during the deposition process, trace defect states are introduced into the film to optimize charge trapping and transport characteristics.

[0021] SS4. Treatment of locations where insulation protection is not required:

[0022] During the deposition process, a masking film is used to cover areas in the brush assembly that do not require insulation protection, or after the insulation film layer is deposited, the film layer formed in the location where insulation protection is not required is selectively removed by using a high-precision laser beam cutting or focused ion beam etching process.

[0023] SS5. Heat treatment and modification of the film surface:

[0024] After the film deposition is completed, the entire brush assembly is heat-treated to eliminate residual stress from the deposition process. The surface of the outer insulating film is modified using low-energy ion implantation technology to improve the interfacial bonding between the film and the brush body and the solder joints between the brush and the wire, thereby enhancing the mechanical properties and stability of the film.

[0025] Through the above steps, this invention provides a method for improving the insulation performance of space conductive slip ring brushes in spacecraft, ensuring a stable electrical connection between the brush and the conductive ring in extreme space environments such as vacuum, strong radiation, and extreme temperature changes. It is suitable for signal or power transmission in equipment such as solar panel drive mechanisms, control torque gyroscopes, laser communication pointing mechanisms, and space scanning mechanisms.

[0026] (III) Technical Effects

[0027] Compared with the prior art, the method for preparing the spacecraft space conductive slip ring and its high-insulation brush of the present invention has the following beneficial and significant technical effects:

[0028] (1) This invention proposes a method for preparing a spacecraft conductive slip ring and its high-insulation brush. The inner insulating film is made of a polymer material doped with thermal conductivity and flexibility modifiers, which endows the film with good insulation properties and a certain degree of tensile strength, ensuring the contact force and transmission efficiency after brush assembly. The outer insulating film introduces high dielectric constant and corrosion-resistant groups to improve insulation strength and environmental adaptability. By selecting the materials of the inner and outer insulating films, this invention enables the brush to meet dielectric strength requirements while possessing a certain degree of tensile strength, so that the contact force caused by the deformation after brush assembly is not affected.

[0029] (2) This invention uses PVD vapor deposition technology to prepare inner and outer insulating films. The para-xylene polymer used has excellent electrical insulation and protective properties, which can effectively resist faults caused by charged wear debris generated by the slip ring. Para-xylene polymer is a polymer material, and its active small molecules are deposited on a micro-sized substrate to form a film layer with uniform thickness and good density, which can effectively reduce the risk of discharge at the tip of the brush in a vacuum. The active molecules of para-xylene polymer have good penetrability and can penetrate into any pore, so as to uniformly coat the irregular surface formed by the welding point of the wire and the brush, reducing the risk of charge accumulation and discharge in the vacuum at this part. Para-xylene polymer has good moisture-proof, waterproof, anti-corrosion atmospheric, salt spray and mold-proof effects, which can effectively improve the ground storage period of the conductive slip ring. Para-xylene coating can be used as the final step in the preparation of the brush assembly, after the brush is formed. The film layer will not be damaged by external forces during brush forming. The xylene polymer is coated by PVD, and the material is non-flowable. The film layer is uniform and will not cause bridging or accumulation on the bending surface and solder joints of the brush, thus ensuring uniform brush stress.

[0030] (3) For locations where coating is not required or where boundary requirements are not high, the present invention can employ masking and mechanical cutting; while for locations with high boundary requirements (e.g., contact points), laser removal can be used. Laser removal can effectively control the removal location, resulting in conductive locations with high dimensional accuracy and clear boundaries. For film layers of different thicknesses, the film layer to be removed can be vaporized by controlling the laser energy range, achieving the effect of removing the film layer without damaging the brush metal body, and without generating excess material.

[0031] (4) The multilayer insulating film prepared by the present invention has excellent comprehensive properties such as electrical insulation, high and low temperature resistance, corrosion resistance and weather resistance. It can effectively resist harsh conditions such as space environment radiation and atomic oxygen corrosion, and improve the working reliability of slip rings. The good protection and barrier effect also significantly improves the ground storage period of slip ring products. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a space disk-type conductive slip ring structure suitable for use in spacecraft.

[0033] Figure 2 yes Figure 1 Side view;

[0034] Figure 3 This is a schematic diagram of the brush assembly (brushes in the form of brush blocks) in a disc-type conductive slip ring.

[0035] Figure 4 This is a schematic diagram of a space cylindrical conductive slip ring structure suitable for use in spacecraft.

[0036] Figure 5 This is a schematic diagram showing the conductive position of the brush and the conductive ring;

[0037] Figure 6 This is a schematic diagram of the brush assembly (brushes in the form of bristles) in a cylindrical conductive slip ring.

[0038] Figure 7 This is a schematic diagram of the cross-sectional structure of the coated brush component (in the form of bristles) in the brush assembly;

[0039] Figure 8 This is a schematic diagram of the method for improving the insulation performance of space conductive slip ring brushes in spacecraft according to the present invention.

[0040] Explanation of reference numerals in the attached figures:

[0041] Conductive ring 10, brush assembly 20, brush support frame 21, brush 22, inner insulating film 23, outer insulating film 24, solder joint between brush and wire 25, contact point between brush and conductive ring 26. Detailed Implementation

[0042] To better understand the present invention, the following embodiments further illustrate its content. Throughout the accompanying drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The described embodiments are some, but not all, of the embodiments of the present invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. The structure and technical solutions of the present invention will be further described in detail below with reference to the accompanying drawings, providing one embodiment of the present invention.

[0043] The purpose of this invention is to provide a method for preparing a spacecraft conductive slip ring and its high-insulation brush. By using a polymer insulating material to perform PVD vapor deposition on the surface of the slip ring and brush, a double-layer insulating film with uniform thickness, good adhesion, strong toughness, and high dielectric strength is formed. This achieves comprehensive insulation protection for the brush body and other components, avoids the influence of charged abrasive debris, improves the insulation performance of the brush, reduces the risk of discharge in the space environment, and extends the service life of the conductive slip ring.

[0044] Example 1

[0045] As a specific example, such as Figures 1-7 As shown, the spacecraft conductive slip ring structure of the present invention can be a disk-type conductive slip ring structure (e.g., Figures 1-3 As shown), it can also be a cylindrical conductive slip ring structure (such as...). Figures 4-6 As shown), to improve the insulation performance of the brush and ensure a stable electrical connection between the brush and the conductive ring in extreme space environments such as vacuum, strong radiation, and extreme temperature changes, it is suitable for signal or power transmission in equipment such as solar panel drive mechanisms, control torque gyroscopes, laser communication pointing mechanisms, and space scanning mechanisms. The conductive slip ring includes at least a conductive ring 10 and a brush assembly 20. The brush assembly 20 includes a brush support frame 21 and a brush 22 (which can be...). Figure 3 The brush block format shown can also be Figure 6 (The bristle form shown, or other suitable structural form).

[0046] An insulating film layer is formed on the main body of each brush 22 in the brush assembly 20 and on the surface of the solder joint 25 between each brush and the wire. The insulating film layer has a double-layer structure and is formed on the brush surface using a high-molecular insulating material, p-xylene polymer, through a PVD vapor deposition process. It includes an inner insulating film 23 and an outer insulating film 24 (e.g., ...). Figure 7 (As shown).

[0047] The inner insulating film 23 forms the insulating substrate for the main body of the brush 22 and the solder joint 25 between the brush and the wire. The polymer insulating material used is doped with a copolymer monomer with high thermal conductivity and flexibility and / or has added fillers with high thermal conductivity and high elongation to improve the thermal conductivity and tensile properties of the inner insulating film. In its PVD vapor deposition process, the deposition rate is reduced to ensure the density and uniformity of the film layer, and the substrate temperature is controlled during the deposition process to reduce the thermal stress and dimensional changes of the material during the deposition process and ensure the mechanical stability of the film layer.

[0048] The outer insulating film 24 covers the outer surface of the inner insulating film 23. The polymer insulating material used in the outer insulating film is doped with polar copolymer monomers with high dielectric constant and environmental corrosion resistance and / or has high dielectric constant and weather-resistant fillers added to improve the dielectric properties and environmental adaptability of the outer insulating film. In the PVD vapor deposition process, the deposition rate and vacuum degree are appropriately increased to ensure the uniformity and adhesion of the film layer. By controlling the substrate temperature and ion implantation during the deposition process, appropriate defect states are introduced into the film layer to optimize the charge carrier trapping and transport characteristics.

[0049] In some preferred embodiments, the polymer insulating material used in the inner insulating film 23 incorporates high thermal conductivity and flexibility comonomers including polyphenylene ether (PPE) and / or polyurethane (PU), and high thermal conductivity and high elongation fillers including carbon nanotubes (CNTs) and / or alumina nanoparticles (Al2O3). High elongation fillers include polyethylene terephthalate (PET) and / or fibrous zirconium stannate nanowires. Furthermore, the polymer insulating material is modified with organosilicon crosslinking agents or acrylate crosslinking agents. Through the synergistic effect of these materials, the formed inner insulating film possesses excellent thermal conductivity and mechanical strength, while also exhibiting significant ductility and crack resistance, thus adapting to the complex operating environment of spacecraft.

[0050] Furthermore, during the PVD vapor deposition process of the inner insulating film 23, the deposition rate is controlled at 5-15 nm / min, and the substrate temperature is controlled at 100-150℃. By precisely controlling the deposition rate and substrate temperature, the density and uniformity of the film can be ensured, internal defects and stress can be reduced, thereby improving the mechanical and thermal stability of the film and meeting the requirements for long-term use in extreme space environments.

[0051] Simultaneously, after deposition, the inner insulating film 23 undergoes low-temperature annealing heat treatment at 80-150℃ for 2-4 hours to further eliminate residual stress from the deposition process. Surface modification via plasma active oxygen / argon ion beam bombardment improves the interfacial bonding between the film and the brush body, as well as the solder joints between the brush and the wires. Heat treatment enhances the mechanical properties and stability of the film, while surface modification improves its adhesion and wear resistance, ensuring the reliability and durability of the inner insulating film during brush operation.

[0052] In some preferred embodiments, the high dielectric constant and environmentally resistant polar comonomers doped in the polymer insulating material used for the outer insulating film 24 include polyphenylene sulfide (PPS) and / or fluorinated polymers (PTFE); the added high dielectric constant fillers include barium titanate (BaTiO3) and / or lithium niobate (LiNbO3); and the added weather-resistant fillers include silica (SiO2) nanoparticles and / or boron nitride (BN) micropowder. Through this combination of materials, the outer insulating film not only possesses a high dielectric constant and excellent electrical properties, but also exhibits excellent environmental corrosion resistance and weather resistance, ensuring stability and reliability in extreme space environments.

[0053] Meanwhile, during the PVD vapor deposition of the outer insulating film 24, its deposition rate is higher than that of the inner insulating film and is controlled at 20-50 nm / min. During the deposition process, the substrate temperature is controlled at 80-120℃ and the vacuum degree is controlled at 10. -4 -10 -6 Pa, and ion beam-assisted deposition was used to induce certain defect states through ion implantation in order to optimize the charge trapping and transport properties of the film.

[0054] Furthermore, after deposition, the outer insulating film 24 preferably undergoes low-temperature annealing, with the annealing temperature controlled at 120-150℃ for 1-3 hours, to reduce residual stress in the film and improve its mechanical properties. Simultaneously, ultraviolet light irradiation is used to modify the film surface, enhancing the radiation resistance and surface hardness of the outer insulating film. Through annealing and surface modification, the overall performance of the outer insulating film is further enhanced, ensuring its long-term stability and reliability in extreme space environments.

[0055] In some preferred embodiments, for locations where insulation protection is not required, including the brush support 21 and the contact points 26 between each brush 22 and the conductive ring (e.g., Figure 5 As shown, before forming an insulating film layer by PVD vapor deposition on the brush surface, a mask with good barrier properties is used to cover and shield this area in advance, so that the insulating film layer is selectively deposited on the metal active surface area of ​​the brush body part that needs insulation protection and the solder joint between the brush and the wire; or after the insulating film layer is prepared, the film layer formed in the position that does not need insulation protection is selectively removed by using high-precision laser beam cutting or focused ion beam etching process.

[0056] Example 2

[0057] Based on Embodiment 1 above, this embodiment focuses on the preparation method of the high-insulation-performance brush in the above structure of the present invention, such as... Figure 8 As shown, the method mainly includes the following steps during implementation:

[0058] SS1. Brush Surface Preparation:

[0059] The active metal surfaces of the brush body and the solder joints between the brush and the conductor in the conductive slip ring of the spacecraft undergo chemical cleaning and / or ion beam polishing pretreatment to remove oxides, contaminants, and microparticles, ensuring the cleanliness and activity of the brush body and solder joints. Alternatively, plasma treatment technology can be used to activate the brush body and solder joints for 30-60 seconds at a power of 50-100W.

[0060] SS2. Preparation of the inner insulating film:

[0061] Using PVD vapor deposition, by controlling the proportion of reactive gases, total pressure, ion energy and / or substrate temperature parameters, and by reducing the deposition rate, a layer of polymer insulating material inner insulating film is selectively deposited on the metal active surface of the brush body and the solder joint between the brush and the wire as an insulating substrate. The polymer insulating material is doped with high thermal conductivity and flexible comonomers and / or has added high thermal conductivity and high elongation fillers.

[0062] More specifically, when preparing the inner insulating film using PVD vapor deposition, an electric brush is placed in the PVD deposition chamber. By controlling the reactive gas ratio, total pressure, ion energy, and substrate temperature parameters (e.g., 100-150°C), and by reducing the deposition rate to 10-15 nm / min and the deposition time to 60-120 min, a layer of polymer insulating material is selectively deposited as an insulating substrate on the active metal surface of the electric brush body and the solder joint between the electric brush and the wire. This polymer insulating material is doped with high thermal conductivity and flexibility comonomers (such as polyphenylene ether (PPE) and polyurethane (PU)) and / or contains high thermal conductivity and high elongation fillers (such as carbon nanotubes (CNTs) and alumina nanoparticles (Al₂O₃)) to improve the thermal conductivity and tensile strength of the inner insulating film. By precisely controlling the deposition rate and substrate temperature, the density and uniformity of the film layer can be ensured, internal defects and stress can be reduced, thereby improving the mechanical and thermal stability of the film layer and meeting the requirements for long-term use in extreme space environments.

[0063] In addition, after deposition, the inner insulating film undergoes low-temperature annealing heat treatment at 80-150℃ for 2-4 hours to further eliminate residual stress from the deposition process. Surface modification via plasma active oxygen / argon ion beam bombardment improves the interfacial bonding between the film and the brush body, as well as the solder joints between the brush and the conductors. Heat treatment enhances the mechanical properties and stability of the film, while surface modification improves adhesion and wear resistance, ensuring the reliability and durability of the inner insulating film during brush operation.

[0064] SS3. Preparation of the outer insulating film:

[0065] By employing PVD vapor deposition, a polymer insulating material outer insulating film is deposited on the outer surface of the inner insulating film by appropriately increasing the deposition rate and vacuum level and controlling the substrate temperature during the deposition process. This outer insulating film is doped with polar copolymers with high dielectric constant and environmental corrosion resistance and / or filled with fillers with high dielectric constant and weather resistance. Furthermore, by controlling the energy and dosage of implanted ions during the deposition process, trace defect states are introduced into the film to optimize charge trapping and transport characteristics.

[0066] More specifically, PVD vapor deposition was employed, by appropriately increasing the deposition rate to 20-30 nm / min and the vacuum level (controlled at 10). -4 -10 -6 A polymer insulating material outer insulating film is deposited on the outer surface of the inner insulating film by controlling the substrate temperature during the deposition process at 90-110℃. This polymer insulating material is doped with polar comonomers with high dielectric constant and environmental corrosion resistance (such as polyphenylene sulfide PPS and fluorinated polymer PTFE) and / or filled with fillers with high dielectric constant and weather resistance (such as barium titanate BaTiO3 and lithium niobate LiNbO3). During the deposition process, an appropriate amount of defect states are introduced into the film by controlling the energy and dosage of implanted ions to optimize charge trapping and transport characteristics.

[0067] In addition, after deposition, the outer insulating film undergoes low-temperature annealing at 120-150℃ for 1-3 hours to reduce residual stress and improve its mechanical properties. Simultaneously, ultraviolet light irradiation is used to modify the film surface, enhancing its radiation resistance and surface hardness. These annealing and surface modifications further enhance the overall performance of the outer insulating film, ensuring its long-term stability and reliability in extreme space environments.

[0068] SS4. Treatment of locations where insulation protection is not required:

[0069] For locations that do not require insulation protection, including the brush support frame and the contact points between each brush and the conductive ring, before forming an insulating film layer on the surface of the brush body and the solder joints between the brush and the conductor using PVD vapor deposition, a metal mask or a high-temperature ceramic mask with good barrier properties is used to cover and shield this area. This allows the insulating film layer to be selectively deposited on the active metal surface areas of the brush body and the solder joints between the brush and the conductor that require insulation protection. Alternatively, after the insulating film layer is prepared, the film layer formed in locations that do not require insulation protection can be selectively removed by using high-precision laser beam cutting or focused ion beam etching processes.

[0070] SS5. Heat treatment and modification of the film surface:

[0071] After the film deposition is completed, the entire brush assembly is heat-treated to eliminate residual stress from the deposition process. The surface of the outer insulating film is modified using low-energy ion implantation technology to improve the interfacial bonding between the film and the brush body and the solder joints between the brush and the wire, thereby enhancing the mechanical properties and stability of the film.

[0072] Through the above steps, this invention provides a method for improving the insulation performance of space conductive slip ring brushes in spacecraft, ensuring a stable electrical connection between the brush and the conductive ring in extreme space environments such as vacuum, strong radiation, and extreme temperature changes. It is suitable for signal or power transmission in equipment such as solar panel drive mechanisms, control torque gyroscopes, laser communication pointing mechanisms, and space scanning mechanisms.

[0073] In some preferred embodiments, after completing the heat treatment and modification of the film surface, the process also includes steps of conducting insulation performance tests and overall performance tests on the brush assembly, specifically:

[0074] SS6. Insulation performance test of brush assembly:

[0075] Insulation performance tests are performed on the processed brush assembly to ensure that it meets the insulation requirements of space conductive slip rings in spacecraft, including:

[0076] (1) Insulation resistance test:

[0077] Use a ohmmeter to measure the insulation resistance of the brush assembly at a DC voltage of 500V;

[0078] The insulation resistance must be no less than 500MΩ, and the test must last for 1 minute.

[0079] Tests were conducted at normal temperature, high temperature (85℃), and low temperature (-55℃) to ensure the temperature stability of the insulation performance.

[0080] (2) Withstand voltage test:

[0081] A 1000V AC voltage was applied to the brush assembly using a withstand voltage tester;

[0082] The test lasts for 1 minute and must not result in any breakdown or flashover.

[0083] Tests were conducted under normal temperature, high temperature (85℃), and low temperature (-55℃) conditions.

[0084] (3) Dielectric strength test:

[0085] The dielectric strength of the brush assembly was measured using a dielectric strength tester.

[0086] The dielectric strength must be no less than 50kV / mm;

[0087] Tests were conducted under normal temperature, high temperature (85℃), and low temperature (-55℃) conditions.

[0088] (4) Partial discharge test:

[0089] The partial discharge level of the brush assembly was measured using a partial discharge tester.

[0090] The partial discharge level must not exceed 10 pC at the operating voltage.

[0091] In a simulated vacuum environment (1×10⁻⁶) -5 The test was conducted at Pa).

[0092] SS7. Overall performance test of the brush assembly:

[0093] The completed brush assembly undergoes final inspection to ensure it meets the requirements for use as a space conductive slip ring in spacecraft, including:

[0094] (1) Visual inspection:

[0095] The surface of the brush assembly was inspected using a high-powered microscope;

[0096] Ensure that the surface of the insulating film layer is free of obvious defects, cracks, or bubbles;

[0097] Check the insulation film removal at the contact point between the brush and the conductive ring to ensure it is completely removed and the boundaries are clear.

[0098] (2) Dimensional measurement:

[0099] The thickness of the insulating film layer was measured using a precision thickness gauge.

[0100] The film thickness must be within the design range, with an error not exceeding ±5%.

[0101] Measure the critical dimensions of the brush assembly to ensure it meets design requirements.

[0102] (3) Contact resistance test:

[0103] The contact resistance at the point of contact between the brush and the conductive ring was measured using a micro-ohmmeter.

[0104] The contact resistance must not exceed 10mΩ;

[0105] Tests were conducted under normal temperature, high temperature (85℃), and low temperature (-55℃) conditions.

[0106] (4) Simulated environment testing:

[0107] a. Vacuum environment test:

[0108] - Place the brush assembly in 1×10 -5 In a vacuum environment;

[0109] - Keep it for 24 hours and observe whether the insulating film layer peels off or deforms;

[0110] - Test insulation performance and contact resistance under vacuum conditions.

[0111] b. Thermal cycling test:

[0112] - Place the brush assembly in a thermal cycling chamber with a temperature range of -55°C to +85°C;

[0113] - Perform 50 thermal cycles, each lasting 2 hours;

[0114] - Test insulation performance and contact resistance after thermal cycling.

[0115] c. Irradiation test:

[0116] - Place the brush assembly in a simulated space radiation environment;

[0117] - The total dose shall not be less than 100 krad(Si);

[0118] - Test the insulation performance and contact resistance after irradiation.

[0119] (5) Life test:

[0120] Accelerated life testing of the brush assembly was conducted in a simulated space environment.

[0121] The testing time shall be no less than 1,000 hours, or the number of rotations shall be no less than 1 million.

[0122] Regularly measure insulation performance and contact resistance to ensure they remain stable throughout the entire lifespan.

[0123] (6) Electromagnetic compatibility testing:

[0124] Conduct electromagnetic emission and electromagnetic susceptibility tests;

[0125] Ensure that the brush assembly meets the electromagnetic compatibility requirements of the spacecraft.

[0126] Through the above insulation performance test and overall performance test, the performance of the treated brush assembly can be comprehensively evaluated to ensure that it meets the stringent requirements for use in space conductive slip rings in spacecraft, thereby improving the reliability and service life of the product.

[0127] The objectives of this invention have been fully and effectively achieved through the above embodiments. Those skilled in the art will understand that this invention includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments described above. Although the invention has been described with reference to what is currently considered the most practical and preferred embodiments, it should be understood that the invention is not limited to the disclosed embodiments, and any modifications that do not depart from the functional and structural principles of the invention will be included within the scope of the claims.

Claims

1. A spacecraft space conductive slip ring structure, comprising a conductive ring and a brush assembly, characterized in that, An insulating film layer is formed on the main body of each brush in the brush assembly and on the surface of the solder joint between each brush and the wire. The insulating film layer has a double-layer structure, including an inner insulating film and an outer insulating film, wherein: The inner insulating film forms the insulating substrate for the main body of the brush and the solder joint surface between the brush and the wire. The polymer insulating material used contains comonomers with high thermal conductivity and flexibility, and fillers with high thermal conductivity and high elongation. During its PVD vapor deposition process, the deposition rate is reduced to ensure the density and uniformity of the film layer, and the substrate temperature during deposition is controlled to reduce thermal stress and dimensional changes in the material. Furthermore: During the PVD vapor deposition process of the inner insulating film, the deposition rate is controlled at 5-15 nm / min, and the substrate temperature is controlled at 100-150 ℃. After deposition, the inner insulating film is subjected to low-temperature annealing heat treatment at 80-150 °C for 2-4 h, and then surface modified by plasma active oxygen / argon ion beam bombardment. The outer insulating film covers the outer surface of the inner insulating film. The polymer insulating material used in this outer layer is doped with polar copolymers that have high dielectric constant and environmental corrosion resistance, and contains fillers with high dielectric constant and weather resistance. During PVD vapor deposition, the deposition rate and vacuum level are appropriately increased to ensure the uniformity and adhesion of the film. Furthermore, by controlling the substrate temperature and ion implantation during the deposition process, appropriate defect states are introduced into the film to optimize charge carrier trapping and transport characteristics. And wherein: During the PVD vapor deposition of the outer insulating film, the deposition rate is higher than that of the inner insulating film and is controlled at 20-50 nm / min. The substrate temperature is controlled at 80-120 ℃ and the vacuum degree is controlled at 10... -4 -10 -6 Pa, and ion beam-assisted deposition was used to induce certain defect states through ion implantation to optimize the charge trapping and transport properties of the film. After deposition, the outer insulating film undergoes low-temperature annealing at a temperature of 120-150 °C for 1-3 hours. Simultaneously, the film surface is modified by ultraviolet light irradiation. For areas in the brush assembly that do not require insulation protection, including the brush support frame and the contact points between each brush and the conductive ring, before forming an insulating film layer by PVD vapor deposition on the surface of the brush body and the solder joints between the brush and the wire, this area is pre-covered and shielded with a mask that has good barrier properties; or after the insulating film layer is prepared, the film layer formed in the areas that do not require insulation protection is selectively removed by using high-precision laser beam cutting or focused ion beam etching processes.

2. The spacecraft space conductive slip ring structure according to claim 1, characterized in that, The inner insulating film contains high thermal conductivity and flexibility comonomers doped with high thermal conductivity and flexibility, including polyphenylene ether (PPE) and / or polyurethane (PU). The added high thermal conductivity and high elongation fillers include carbon nanotubes (CNTs) and / or alumina nanoparticles (Al2O3). The added high elongation fillers include polyethylene terephthalate (PET) and / or fibrous zirconium stannate nanowires. Furthermore, organosilicon crosslinking agents or acrylate crosslinking agents are introduced into the polymer insulating material.

3. The spacecraft space conductive slip ring structure according to claim 1, characterized in that, The outer insulating film contains polar comonomers doped with its polymer insulating material, including polyphenylene sulfide (PPS) and / or fluorinated polymer (PTFE), high dielectric constant fillers including barium titanate (BaTiO3) and / or lithium niobate (LiNbO3), and weather-resistant fillers including silica (SiO2) nanoparticles and / or boron nitride (BN) micropowder.

4. A method for preparing a high-insulation brush in a spacecraft space conductive slip ring structure according to any one of claims 1 to 3, characterized in that, The preparation method mainly includes the following steps when implemented: SS1. Brush Surface Preparation: Chemical cleaning and / or ion beam polishing pretreatment is performed on the active metal surfaces of the brush body and the solder joints between the brush and the wire in the conductive slip ring of the spacecraft to remove surface contaminants and microparticles and / or surface oxides, contaminants and microparticles, ensuring the cleanliness and activity of the brush body and the solder joints between the brush and the wire. SS2. Preparation of the inner insulating film: Using PVD vapor deposition, by controlling the proportion of reactive gases, total pressure, ion energy and / or substrate temperature parameters, and by reducing the deposition rate, a layer of polymer insulating material inner insulating film is selectively deposited on the metal active surface of the brush body and the solder joint between the brush and the wire as an insulating substrate. The polymer insulating material is doped with high thermal conductivity and flexible comonomers and / or has high thermal conductivity and high elongation fillers added. SS3. Preparation of the outer insulating film: By employing PVD vapor deposition, a polymer insulating material outer insulating film is deposited on the outer surface of the inner insulating film by appropriately increasing the deposition rate and vacuum degree and controlling the substrate temperature during the deposition process. The polymer insulating material of this film is doped with polar copolymers with high dielectric constant and environmental corrosion resistance and / or filled with fillers with high dielectric constant and weather resistance. Furthermore, by controlling the energy and dosage of implanted ions during the deposition process, trace defect states are introduced into the film to optimize charge trapping and transport characteristics. SS4. Treatment of locations where insulation protection is not required: During the deposition process, a masking film is used to cover areas in the brush assembly that do not require insulation protection, or after the insulation film layer is deposited, the film layer formed in the location where insulation protection is not required is selectively removed by using a high-precision laser beam cutting or focused ion beam etching process. SS5. Heat treatment and modification of the film surface: After the film deposition is completed, the entire brush assembly is heat-treated to eliminate residual stress from the deposition process, and the surface of the outer insulating film is modified by low-energy ion implantation technology.

5. The method for preparing a high-insulation brush in a spacecraft space conductive slip ring according to claim 4, characterized in that, After completing the heat treatment and modification of the film surface, the process also includes insulation performance testing and overall performance testing of the brush assembly. SS6. Insulation performance test of brush assembly: Insulation performance tests are performed on the processed brush assemblies to ensure their stability and reliability in extreme space environments, including at least: Under vacuum and extreme temperature conditions, by applying high voltage direct current, the volume resistivity and surface resistivity of the film layer at different vacuum levels and temperatures are tested to ensure that its resistivity performance meets the insulation class requirements. Under high voltage and high frequency electric field conditions, by applying an alternating electric field, the dielectric strength and dielectric loss of the brush assembly at different frequencies and temperatures are tested to ensure that its dielectric performance meets the insulation class requirements; Under high voltage conditions, by applying pulse voltage, the discharge tracking value and corona critical voltage of the brush assembly are tested to ensure that the film layer has excellent anti-corona and high voltage insulation capabilities. SS7. Overall performance test of the brush assembly: The completed brush assembly undergoes a final inspection to ensure it meets the requirements for use as a space conductive slip ring in spacecraft, including at least: Mechanical performance testing: Simulating the vacuum environment and temperature conditions of a spacecraft in orbit, the brush assembly is subjected to tensile, compression and bending tests to ensure its stability and durability under mechanical stress; Thermal cycling test: Simulate the temperature changes during the operation of a spacecraft in orbit, and conduct thermal cycling tests on the brush assembly to ensure its performance stability under extreme temperature changes; Electrical connection testing: Simulating temperature changes during spacecraft operation in orbit, testing the conductivity and stability of the electrical connection between the brush assembly and the conductive ring to ensure the reliability of signal and power transmission; Long-term stability testing: Simulating the vacuum, strong radiation and extreme temperature conditions of the space environment, the brush assembly is subjected to long-term stability testing to evaluate the service life of the brush assembly in complex environments.

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