A motor insulation end plate for aerospace high temperature environment and a preparation method thereof

Abstract

The application discloses an insulating end plate of a motor for aerospace high-temperature environment and a preparation method thereof, and relates to the technical field of composite materials.The preparation method comprises the following steps: pretreating a quartz fiber cloth to obtain pretreated quartz fiber cloth; impregnating polysilazane resin into the pretreated quartz fiber cloth to prepare prepreg; drying the prepreg; stacking the dried prepreg and placing the stacked prepreg in a mold; adopting a stepwise temperature and pressure process to perform mold pressing to obtain an insulating end plate blank; and performing heat treatment on the insulating end plate blank in an inert atmosphere to obtain the insulating end plate of the motor for the aerospace high-temperature environment.The long-term working temperature of the motor insulating end plate can be stabilized to be above 300 DEG C, and the motor insulating end plate can maintain good mechanical strength and insulation reliability in a high-low temperature alternating environment, so that the major technical problem that insulation components of an aerospace motor are prone to softening, decomposition and failure in an extremely high-temperature environment is fundamentally solved.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, specifically relating to an insulating end plate for motors used in high-temperature aerospace environments and its preparation method. Background Technology

[0002] With the rapid development of aerospace technology, the performance requirements for airborne power systems and miniaturized actuation systems are becoming increasingly stringent. As a core actuator in systems such as drives, pump controls, fans, and servos, the reliability of electric motors directly affects the overall performance and safety of aircraft. In these applications, the increasing power of motors and changes in their operating environment mean that high-performance motors often need to operate in extremely harsh environments, with high-temperature environments being one of the most severe challenges.

[0003] Motor end plates (also known as insulating end plates or end covers) are key insulating components in the motor stator assembly. Their main function is to fix the ends of the armature windings and provide reliable electrical insulation to ground (stator core) and between phases. Under normal conditions, end plates are usually made of materials such as epoxy glass cloth laminate (e.g., FR4), polyimide, or phenolic resin, through molding or machining, and their long-term operating temperature generally does not exceed 200℃.

[0004] However, in specific aerospace applications, the high-temperature environments faced by motors far exceed this limit, specifically manifested in the high-temperature environment and the self-heating of the motor windings. First, due to aerodynamic heating, the internal compartment temperatures of near-space vehicles and hypersonic vehicles can be maintained above 200°C for extended periods, and even momentarily reach 300-500°C. Second, to meet high power density requirements, aerospace motors tend to be miniaturized and lightweight, leading to a sharp increase in losses per unit volume and significant winding temperature rise, making the internal ambient temperature of the motor far exceed that of the external environment.

[0005] In the aforementioned high-temperature environments, traditional insulating end plates can no longer fully meet the requirements of advanced aircraft and high-performance motors. Regarding materials, conventional organic insulating materials such as FR4 and phenolic resin have low glass transition temperatures (Tg) and thermal decomposition temperatures. Under long-term operation above 200°C, these materials soften, deform, and lose mechanical strength, making it impossible to effectively secure the windings. Simultaneously, their electrical insulation properties (such as dielectric strength and volume resistivity) decrease significantly, easily triggering partial discharge or breakdown, leading to motor short-circuit failure. Thermodynamically, there is a significant difference in the coefficient of thermal expansion between traditional organic materials and the metal stator core and copper windings. Under severe temperature cycling, this thermal mismatch generates enormous internal stress, causing the insulating end plates to crack and peel off, compromising the integrity of the insulation system. In terms of insulation performance, under high-temperature, low-pressure (high-altitude environment) conditions, the dielectric strength of air decreases, making corona discharge and arcing more likely. Traditional materials lack sufficient resistance to arc erosion and resistivity at high temperatures.

[0006] In existing technologies, a series of studies have been conducted on modifying the polymer matrix to improve the performance of traditional organic insulating materials. For example, Yu Hao and Lu Taiping, in their study "Research on Heat-Resistant Epoxy Resin Insulating Materials," used epoxy resin / polyurethane interpenetrating network (EP / PU IPN) technology to increase the heat resistance index of the material to 155℃ (F grade). However, this actually represents the upper limit of temperature resistance that can be achieved through complex modification and optimization of traditional epoxy resin. Zuo Xinbin et al., in their study "Preparation and Application Performance Research of an Epoxy Resin Composite Insulating Material," focused on improving the dielectric and flashover properties of epoxy resin by adding nano-SiO2 / Al2O3 fillers; however, this still did not overcome the heat resistance limitations of the epoxy resin matrix itself. In addition, Ai Lianghui et al., in their study "Performance Research of Polypropylene / Polyphenylene Ether Insulating Materials," developed a PP / PPE / ADP composite material, but it is mainly used as an insulating layer material for wires and cables, focusing on single functional properties such as insulation, flame retardancy, and wear resistance. Its long-term operating temperature is only about 90℃, limiting its application temperature range. It should be noted that the above studies mainly provide "insulating materials" that require secondary processing and molding, such as casting materials or molding compounds. The methods are mostly targeted remedies for certain performance shortcomings of existing polymer matrices, and have not systematically solved the insulation reliability problems under high temperature, thermal mismatch and complex environments.

[0007] To address these challenges, existing technologies have attempted to use high-performance engineering plastics or ceramic-filled composite materials, but these still have shortcomings. For example, while pure polyimide has good temperature resistance, it is expensive, difficult to process, and highly hygroscopic; while ceramic materials have excellent high-temperature resistance, they are brittle, have complex bonding processes with metals, and are difficult to process into complex insulation structures. Summary of the Invention

[0008] In order to overcome the shortcomings of the prior art, the present invention aims to provide an insulating end plate for motors used in high-temperature environments of aerospace and its preparation method, so as to solve the technical problems of temperature difference resistance, unstable insulation performance, poor thermal expansion synergy with metal materials and complex processing of existing insulating end plate structures.

[0009] To achieve the above objectives, the present invention employs the following technical solution: In a first aspect, the present invention provides a method for preparing an insulating end plate for an electric motor used in high-temperature aerospace environments, comprising the following steps: The quartz fiber cloth is pretreated to obtain the pretreated quartz fiber cloth; A prepreg is prepared by impregnating polysilazane resin into pretreated quartz fiber cloth. The prepreg is dried, and the dried prepreg is stacked and placed in a mold. It is then molded using a stepped heating and pressing process to obtain an insulating end plate blank. The insulating end plate blank is heat-treated in an inert atmosphere to obtain an insulating end plate for motors used in high-temperature aerospace environments.

[0010] A further improvement of the present invention is that the pretreatment of the quartz fiber cloth includes: sealing the edges of the cut quartz fiber cloth, followed by ultrasonic cleaning and drying.

[0011] A further improvement of the present invention is that the quartz fiber cloth is made of α-SiO2 material, has a thickness of 0.1mm, and has a plain weave structure.

[0012] A further improvement of the present invention is that the viscosity of the polysilazane resin at 25°C is 300-400 mPa·s.

[0013] A further improvement of the present invention is that the polysilazane resin is impregnated in the pretreated quartz fiber cloth by vacuum impregnation or brush coating.

[0014] A further improvement of the present invention is that the drying process is carried out at a temperature of 75-85°C for a time of 1.5-2.5 hours.

[0015] A further improvement of the present invention is that the stepped heating and pressurizing process in the compression molding includes the following stages: the first stage heats up to 120-150℃ at a rate of 5℃ / min, with a pressure of 0.5-4 MPa, and holds for 30-60 min; the second stage heats up to 170-180℃ at a rate of 3℃ / min, with a pressure of 2-4 MPa, and holds for 0.5-1 h; the third stage heats up to 220-250℃ at a rate of 3℃ / min, with a pressure of 5-10 MPa, and holds for 1-2 h, and then cools down in the furnace to below 80℃ before demolding.

[0016] A further improvement of the present invention is that the heat treatment temperature is 300-400℃, the time is 0.5-1.5h, and the inert atmosphere is nitrogen.

[0017] Secondly, the present invention also provides an insulating end plate for motors used in high-temperature aerospace environments, which is prepared by the above-described method.

[0018] A further improvement of the present invention is that the thickness of the motor insulation end plate is 0.5~1.5mm.

[0019] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a method for preparing an insulating end plate for motors used in high-temperature aerospace environments. First, quartz fiber cloth is pretreated to effectively remove impurities from the fiber surface and stabilize the woven structure, laying a solid foundation for forming a uniform and dense composite material. Subsequently, the pretreated quartz fiber cloth is impregnated with polysilazane resin. The quartz fiber ensures excellent thermal stability and mechanical strength, while the polysilazane resin undergoes a ceramic transformation during subsequent heat treatment, fundamentally changing the material's nature. In the compression molding stage, a stepped heating and pressurizing process is used to allow the resin to fully flow, wet, and achieve controlled curing, thereby obtaining a preform with a complete structure, precise thickness, and no internal defects. Finally, heat treatment under an inert atmosphere promotes the complete transformation of the resin into a ceramic phase. This allows the final insulating end plate to be made thinner, saving valuable space for the motor windings. More importantly, its long-term operating temperature limit is significantly increased to over 300°C, perfectly solving the core technical problem of softening, decomposition, and insulation performance degradation of traditional organic materials at high temperatures. This provides a reliable guarantee for the long-term stable operation of aerospace motors in harsh high-temperature environments. Attached Figure Description

[0020] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components of the invention.

[0021] Figure 1 This is a schematic flowchart of the method for preparing the motor insulation end plate of the present invention. Detailed Implementation

[0022] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0023] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0024] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0025] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0026] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0027] like Figure 1 As shown, this invention provides a method for preparing an insulating end plate for motors used in high-temperature aerospace environments, comprising the following steps: S1, pre-treat the quartz fiber cloth to obtain the pre-treated quartz fiber cloth; S2, impregnate the pretreated quartz fiber cloth with polysilazane resin to make a prepreg; S3, the prepreg is dried, the dried prepreg is stacked and placed in a mold, and molded by a stepped heating and pressing process to obtain an insulating end plate blank. S4, the insulating end plate blank is heat-treated in an inert atmosphere to obtain an insulating end plate for motors used in high-temperature aerospace environments.

[0028] The quartz fiber cloth is made of α-SiO2 plain weave fabric produced by Hubei Feilihua Company, with a thickness of 0.1mm and a single layer width of 300mm×300mm. The pretreatment includes: cutting the quartz fiber cloth into rectangular sheets according to the outer dimensions (including allowance) of the insulation end plate blank, applying a 0.5mm wide sealing tape along the edge with epoxy acrylate adhesive (65% solid content, viscosity 8000 mPa·s), curing at room temperature for 2 hours, and then ultrasonically cleaning it in an ethanol solution for 30 minutes. The purpose of ultrasonic cleaning is to remove chemical residues and dust and other impurities from the fiber braid to ensure the stability of the insulation performance of the laminated structure. After cleaning, the quartz fiber cloth is taken out and dried in a high-temperature oven at 80℃ for 30 minutes. The dried quartz fiber cloth is then taken out and placed in a dust-free environment for later use.

[0029] The polysilazane (PSN) resin used was a product provided by the Institute of Chemistry, Chinese Academy of Sciences. It had a viscosity of 300-400 mPa·s at 25℃, was free of visible impurities, and was stored in a sealed, dry nitrogen environment. Pretreated quartz fiber cloth was layered into a vacuum impregnation tank. 1.3-2.0 times the mass of a single 300×300mm fiber cloth was weighed and completely coated onto the cloth with a brush. Two quartz fiber cloths of the same size were prepared using this method. After the single quartz fiber cloth was prepared, the surface of the prepreg was checked for impurities. After checking for areas free of impurities and uncoated areas, the two coated PSN prepregs were laid together, and air bubbles between the layers were squeezed out.

[0030] The prepared PSN prepreg is placed in an oven for semi-curing at 75-85℃ for 1.5-2.5 hours. This step addresses the difficulties caused by the high fluidity of PSN resin at room temperature during the molding process. High-fluidity resin flows during molding, leading to a decrease in the prepreg resin brushing ratio, affecting lamination, insulation performance, and mechanical properties of the product. This step allows the resin to form preliminary cross-links at high temperatures, thereby improving processability and product performance. Subsequently, the dried and pre-cross-linked PSN prepreg is placed in a steel mold preheated to 90-120℃. The mold cavity profile is aligned with the negative shape of the insulating end plate.

[0031] The stepped heating and pressurizing process in the compression molding includes the following stages: the first stage heats the material to 120-150℃ at a rate of 5℃ / min, with a pressure of 0.5-4 MPa, and holds it for 30-60 min; the second stage heats the material to 170-180℃ at a rate of 3℃ / min, with a pressure of 2-4 MPa, and holds it at the same temperature and pressure for 0.5-1 h; the third stage heats the material to 220-250℃ at a rate of 3℃ / min, with a pressure of 5-10 MPa, and holds it at the same temperature and pressure for 1-2 h, then cools it in the furnace to below 80℃ and demolds it, obtaining an insulating end plate blank with a smooth surface, no delamination or bulges, and a thickness tolerance of ±0.05 mm; finally, the blank is placed in a tube furnace and heated to 300-400℃ at a rate of 2℃ / min under a nitrogen atmosphere (flow rate 2 L / min), held at the same temperature for 0.5-1.5 h, and then naturally cooled to obtain the finished product. This preparation method eliminates fiber impurities and loose filaments through pretreatment, ensures uniform resin distribution through impregnation, inhibits molding flow through low-temperature drying, achieves dense filling and stress release through stepped molding, and completes the Si-OCN ceramic phase transformation through nitrogen heat treatment.

[0032] Finally, the appearance quality of the molded composite material was checked. The blank sample had no delamination, no bulges, no surface desaturation, and the surface unevenness area was ≤0.5mm. 2 If no visible impurities are found between layers and on the surface, the appearance quality is deemed acceptable. The thickness of the sample is then tested to ensure it meets the standard requirements.

[0033] The present invention also provides an insulating end plate for motors used in high-temperature environments of aerospace, which is prepared by the above-described method and has a thickness of 0.5~2mm.

[0034] The motor insulation end plate described in this invention achieves a fundamental transformation of the composite matrix from organic polymer to inorganic ceramic through a unique material system and heat treatment process. Specifically, the selected polysilazane resin, as a ceramic precursor, has a molecular skeleton dominated by silicon-nitrogen bonds, which inherently possesses superior thermal stability compared to traditional carbon-chain polymers. After molding into a preform, the resin undergoes a pyrolysis-ceramization reaction during a key high-temperature heat treatment step in an inert atmosphere: the molecular chains further crosslink and rearrange, releasing small molecule gases, ultimately forming a three-dimensional network inorganic ceramic structure dominated by silicon, carbon, and nitrogen. This transformation means that the material's temperature resistance is no longer limited by the thermal decomposition temperature of organic matter, but is instead determined by the stable ceramic phase and quartz fiber reinforcement formed. Therefore, the final product breaks through the traditional 200°C operating limit of organic insulation materials, and its long-term operating temperature can stably reach above 300°C. Simultaneously, it maintains good mechanical strength and insulation reliability under alternating high and low temperature environments, fundamentally solving the major technical problem of easy softening, decomposition, and failure of insulation components in aerospace motors under extreme high-temperature environments.

[0035] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0036] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0037] Example 1 This embodiment provides a method for preparing a high-performance insulating end plate for high-temperature aerospace environments, including the following steps: S1. Cut 0.1mm thick plain-weave quartz fiber cloth into 200mm x 200mm pieces, then seal the edges to fix the fiber weave structure. Place the sealed fibers in an industrial ultrasonic cleaner, using ethanol as the cleaning solution, and ultrasonically clean for 30 minutes to remove impurities. Finally, dry the cleaned fiber cloth in an 80℃ forced-air drying oven for 30 minutes, then set aside for later use.

[0038] S2. Prepare liquid polysilazane resin (PSN) with a viscosity of 350 mPa·s (25℃). First, dilute the PSN resin with anhydrous ethanol at a mass ratio of 1:0.2 to prepare the impregnation solution. Using a vacuum impregnation method, pass 12 layers of quartz fiber cloth pretreated in S1 through the impregnation tank one by one to ensure full impregnation. Stack the impregnated fiber cloths together and use a doctor blade to control the resin content so that the mass ratio of resin to quartz fiber in the final prepreg is 55:45.

[0039] S3, Place the stacked prepregs in a forced-air drying oven and dry at 80°C for 2 hours to remove solvent and allow the resin to undergo initial crosslinking; Place the dried prepregs into a mold preheated to 120°C, apply an initial pressure of 1 MPa, and perform stepwise temperature and pressure increases according to the following procedure: First stage: Heat from 100℃ to 150℃ at a rate of 5℃ / min, while simultaneously increasing the pressure to 3 MPa, and hold at 150℃ and 3 MPa for 30 minutes. Second stage: Continue to heat up to 175℃ at a rate of 3℃ / min, maintain pressure at 3 MPa, and hold at 175℃ and 3 MPa for 1 hour. Third stage: Continue heating to 220℃ at a rate of 3℃ / min, while simultaneously increasing the pressure to 5 MPa, and maintain the temperature and pressure at 220℃ and 5 MPa for 2 hours; after the heat preservation is completed, stop heating, allow the mold to cool naturally to below 80℃ under pressure, demold, and obtain an insulating end plate blank with a thickness of 1mm.

[0040] In step S4, the insulating end plate blank obtained in step S3 is placed in a high-temperature oven, and nitrogen gas is introduced into the oven as a protective atmosphere. The temperature is then increased to 350°C at a rate of 2°C / min and held at 350°C for 1 hour. This process allows the polysilazane resin to complete its ceramization transformation. Finally, it is naturally cooled to room temperature to obtain the final high-performance motor insulating end plate.

[0041] Example 2 This embodiment provides a method for preparing a high-performance insulating end plate for high-temperature aerospace environments, including the following steps: S1. Cut 0.1mm thick plain-weave quartz fiber cloth into 200mm x 200mm pieces, then seal the edges to fix the fiber weave structure. Place the sealed fibers in an industrial ultrasonic cleaner, using ethanol as the cleaning solution, and ultrasonically clean for 30 minutes to remove impurities. Finally, dry the cleaned fiber cloth in an 80℃ forced-air drying oven for 30 minutes, then set aside for later use.

[0042] S2, prepare liquid polysilazane resin (PSN) with a viscosity of 350 mPa·s (25℃). Using a brush coating method, uniformly brush the undiluted liquid polysilazane resin (PSN) onto one side of two layers of quartz fiber cloth pretreated in S1, and then laminate them. Control the amount of brush coating so that the mass ratio of resin to quartz fiber cloth in the final prepreg is 60:40.

[0043] S3, Place the stacked prepregs in a forced-air drying oven and dry at 75°C for 2.5 hours to remove solvent and allow the resin to undergo initial crosslinking; Place the dried prepregs into a mold preheated to 90°C, apply an initial pressure of 0.5 MPa, and perform stepwise temperature and pressure increases according to the following procedure: First stage: Heat to 150℃ at a rate of 5℃ / min, maintain pressure at 0.5 MPa, and hold at 150℃ and 0.5 MPa for 60 minutes. Second stage: Heat up to 170℃ at a rate of 3℃ / min, increase pressure to 2 MPa, and maintain the temperature and pressure at 170℃ and 2 MPa for 1 hour. The third stage: the temperature is raised to 225℃ at a rate of 3℃ / min, the pressure is raised to 6 MPa, and the temperature and pressure are maintained at 225℃ and 6 MPa for 1.5 hours. After the heat preservation is completed, the heating is stopped, and the mold is allowed to cool naturally to below 80℃ under the pressure. The mold is then demolded to obtain an insulating end plate blank with a thickness of 1mm.

[0044] In step S4, the insulating end plate blank obtained in step S3 is placed in a high-temperature oven, and nitrogen gas is introduced into the oven as a protective atmosphere. The temperature is then raised to 300°C at a rate of 2°C / min and held at 300°C for 1.5 hours. This process allows the polysilazane resin to complete its ceramization transformation. Finally, it is naturally cooled to room temperature to obtain the final high-performance motor insulating end plate.

[0045] Example 3 This embodiment provides a method for preparing a high-performance insulating end plate for high-temperature aerospace environments, including the following steps: S1. Cut 0.1mm thick plain-weave quartz fiber cloth into 200mm x 200mm pieces, then seal the edges to fix the fiber weave structure. Place the sealed fibers in an industrial ultrasonic cleaner, using ethanol as the cleaning solution, and ultrasonically clean for 30 minutes to remove impurities. Finally, dry the cleaned fiber cloth in an 80℃ forced-air drying oven for 30 minutes, then set aside for later use.

[0046] S2. Prepare liquid polysilazane resin (PSN) with a viscosity of 350 mPa·s (25℃). First, dilute the PSN resin with anhydrous ethanol at a mass ratio of 1:0.2 to prepare the impregnation solution. Using a vacuum impregnation method, pass 8 layers of quartz fiber cloth pretreated in S1 through the impregnation tank one by one to ensure full impregnation. Stack the impregnated fiber cloths together and use a doctor blade to control the resin content so that the mass ratio of resin to quartz fiber in the final prepreg is 40:60.

[0047] S3, Place the stacked prepregs in a forced-air drying oven and dry at 85°C for 1.5 hours to remove solvent and allow the resin to undergo initial crosslinking; Place the dried prepregs into a mold preheated to 110°C, apply an initial pressure of 1 MPa, and perform stepwise temperature and pressure increases according to the following procedure: First stage: Heat up to 130℃ and start holding the temperature. The pressure is increased to 4 MPa within 10 minutes after the start of the holding period, and then maintained at 130℃ and 2 MPa for 40 minutes. Second stage: Heat to 180℃ at a rate of 2℃ / min, maintain pressure at 4 MPa, and hold at 180℃ for 30min; The third stage: the temperature is increased to 250℃ at a rate of 5℃ / min, and the pressure is increased to 10 MPa simultaneously. The temperature and pressure are maintained at 250℃ and 10 MPa for 1 hour. After the heat preservation is completed, the heating is stopped, and the mold is allowed to cool naturally to below 80℃ under the pressure. The mold is then demolded to obtain an insulating end plate blank with a thickness of 1mm.

[0048] In step S4, the insulating end plate blank obtained in step S3 is placed in a high-temperature oven, and nitrogen gas is introduced into the oven as a protective atmosphere. The temperature is then raised to 400°C at a rate of 2°C / min and held at 400°C for 0.5 hours. This process allows the polysilazane resin to complete its ceramization transformation. Finally, it is naturally cooled to room temperature to obtain the final high-performance motor insulating end plate.

[0049] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for preparing an insulating end plate for a motor used in high-temperature aerospace environments, characterized in that, Includes the following steps: The quartz fiber cloth is pretreated to obtain the pretreated quartz fiber cloth; A prepreg is prepared by impregnating polysilazane resin into pretreated quartz fiber cloth. The prepreg is dried, and the dried prepreg is stacked and placed in a mold. It is then molded using a stepped heating and pressing process to obtain an insulating end plate blank. The insulating end plate blank is heat-treated in an inert atmosphere to obtain an insulating end plate for motors used in high-temperature aerospace environments.

2. The method for preparing an insulating end plate for a motor used in high-temperature aerospace environments according to claim 1, characterized in that, The pretreatment of the quartz fiber cloth includes: sealing the edges of the cut quartz fiber cloth, then ultrasonically cleaning and drying it.

3. The method for preparing an insulating end plate for a motor used in high-temperature aerospace environments according to claim 1, characterized in that, The quartz fiber cloth is made of α-SiO2 material, with a thickness of 0.1mm and a plain weave structure.

4. The method for preparing an insulating end plate for a motor used in high-temperature aerospace environments according to claim 1, characterized in that, The viscosity of the polysilazane resin at 25°C is 300-400 mPa·s.

5. The method for preparing an insulating end plate for a motor used in high-temperature aerospace environments according to claim 1, characterized in that, The polysilazane resin is impregnated in the pretreated quartz fiber cloth by vacuum impregnation or brush coating.

6. The method for preparing an insulating end plate for a motor used in high-temperature aerospace environments according to claim 1, characterized in that, The drying process is carried out at a temperature of 75-85℃ for 1.5-2.5 hours.

7. The method for preparing an insulating end plate for a motor used in high-temperature aerospace environments according to claim 1, characterized in that, The stepped heating and pressurizing process in the compression molding includes the following stages: the first stage heats the temperature to 120-150℃ at a rate of 5℃ / min, with a pressure of 0.5-4 MPa, and holds for 30-60 min; the second stage heats the temperature to 170-180℃ at a rate of 3℃ / min, with a pressure of 2-4 MPa, and holds for 0.5-1 h; the third stage heats the temperature to 220-250℃ at a rate of 3℃ / min, with a pressure of 5-10 MPa, and holds for 1-2 h, and then cools in the furnace to below 80℃ before demolding.

8. The method for preparing an insulating end plate for a motor used in high-temperature aerospace environments according to claim 1, characterized in that, The heat treatment is performed at a temperature of 300-400℃ for 0.5-1.5 hours, using nitrogen as the inert atmosphere.

9. An insulating end plate for motors used in high-temperature aerospace environments, characterized in that, It is prepared by any one of claims 1 to 8.

10. A motor insulation end plate for high-temperature aerospace environments according to claim 9, characterized in that, The thickness of the motor insulation end plate is 0.5~1.5mm.

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