Oil-cooled motor stator inner wall sealing composite material and preparation method thereof

Abstract

The invention relates to an oil-cooled motor stator inner wall sealing composite material and a preparation method thereof, and belongs to the technical field of sealing composites.The preparation method of the oil-cooled motor stator inner wall sealing composite material comprises the steps that a resin matrix is obtained, and a planar fiber reinforcement or an annular fiber reinforcement is prepared; preparing a planar fiber-reinforced resin preform or an annular fiber-reinforced resin preform, and packaging the planar fiber-reinforced resin preform or the annular fiber-reinforced resin preform; and obtaining the oil-cooled motor stator inner wall sealing composite material. The method for preparing the sealing composite material for the inner wall of the oil-cooled motor stator is simple in step, controllable in cost and beneficial to large-scale production.

Description

Technical Field

[0001] The present invention belongs to the technical field of sealing composite materials, and in particular relates to a sealing composite material for the inner wall of an oil-cooled motor stator and a preparation method thereof. Background Art

[0002] In recent years, the development of the new energy vehicle industry has been thriving. With the introduction of the national corresponding industrial planning roadmap, the cost and efficiency of the electric drive system of new energy vehicles have received special attention. The drive motor, as the core of the electric drive system, provides driving power for new energy vehicles and determines the comprehensive performance of new energy vehicles. How to improve the efficiency of the motor and reduce its cost has become one of the core issues in solving the cost and efficiency of electric drive.

[0003] Increasing the speed of the motor is a relatively obvious way to increase power density and reduce costs. The increase in motor speed depends largely on the heat dissipation performance of the motor. Accordingly, improving the cooling efficiency of the motor is the key to improving motor power density and reducing costs. The existing motor cooling methods are mainly divided into three types: air cooling, water cooling and oil cooling. In recent years, oil cooling has gradually gained a clear advantage in the cooling system due to its high cooling efficiency, as the cooling oil can directly contact the iron core and windings. At present, the cooling system of a typical oil-cooled motor generally cools the motor by spraying or throwing oil on the windings at the ends of the motor. The oil circuit is set on the iron core, the iron core is axially perforated, and small holes are opened at the oil circuit and the ends of the windings. During operation, the cooling oil passes axially through the iron core to take away the heat generated by the iron core, and the small holes at the ends of the oil circuit spray oil onto the windings, thereby cooling the ends of the windings.

[0004] However, axial drilling of the core can easily affect the electromagnetic performance of the motor. Secondly, the flow direction of the cooling oil sprayed to the end of the winding is difficult to control. Some cooling oil is directly sprayed or dripped onto other parts. This part of the cooling oil cannot effectively dissipate the heat of the winding, reducing the cooling efficiency and affecting the cleanliness of the motor. At the same time, some cooling oil enters the air gap between the stator and rotor, which will cause certain mechanical losses, reduce the efficiency and service life of the motor, and has great limitations. Summary of the invention

[0005] The present invention proposes a composite material for sealing the inner wall of an oil-cooled motor stator and a preparation method thereof, aiming to partially or completely solve the technical problems in the prior art. The technical solution of the present invention is as follows:

[0006] In a first aspect, a method for preparing a composite material for sealing the inner wall of an oil-cooled motor stator comprises:

[0007] Step S100: obtaining a resin matrix and preparing a planar fiber reinforcement or a ring-shaped fiber reinforcement;

[0008] Step S200: Prepare a planar fiber-reinforced resin preform or an annular fiber-reinforced resin preform, and package the planar fiber-reinforced resin preform or the annular fiber-reinforced resin preform;

[0009] Step S300: Take out the planar fiber-reinforced resin preform from the packaged planar fiber-reinforced resin preform, cut and shape the planar fiber-reinforced resin preform to obtain a fiber-reinforced resin preform splicing body, spread the fiber-reinforced resin preform splicing body along the inner wall of the oil-cooled motor stator, and press and fit the fiber-reinforced resin preform splicing body with the inner wall of the oil-cooled motor stator; Cure the fiber-reinforced resin preform splicing body after it is attached to the inner wall of the motor stator to obtain a sealing composite material for the inner wall of the oil-cooled motor stator;

[0010] Or, take out the annular fiber-reinforced resin preform from the packaged annular fiber-reinforced resin preform, spread the annular fiber-reinforced resin preform along the inner wall of the oil-cooled motor stator, press and fit the annular fiber-reinforced resin preform with the inner wall of the oil-cooled motor stator, and cure the annular fiber-reinforced resin preform after it is attached to the inner wall of the motor stator to obtain a sealing composite material for the inner wall of the oil-cooled motor stator.

[0011] Optionally, step S200 includes:

[0012] Step S201: Send the planar fiber reinforcement into a padding device containing a resin matrix solution for padding treatment to obtain a prepreg, and send the prepreg into an oven for pre-curing to obtain a planar fiber-reinforced resin preform;

[0013] Step S202: Attach a layer of release paper to the upper surface of the planar fiber-reinforced resin preform and a layer of PE film to the lower surface, and pack it into a roll to obtain a packaged planar fiber-reinforced resin preform;

[0014] And / or, step S300 includes:

[0015] Step S301: Take out the packaged planar fiber-reinforced resin preform, remove the release paper on the upper surface and the PE film on the lower surface to obtain a planar fiber-reinforced resin preform, cut and shape the planar fiber-reinforced resin preform to obtain a fiber-reinforced resin preform splicing body;

[0016] Step S302: Spread one fiber-reinforced resin prefabricated splicing body along the inner wall of the oil-cooled motor stator. The one fiber-reinforced resin prefabricated splicing body is spliced end to end to form one splicing seam, and the size of the one fiber-reinforced resin prefabricated splicing body is matched with the size of the inner wall of the oil-cooled motor stator, and it is bonded to the inner wall of the oil-cooled motor stator by using the low viscosity of the resin; or, spread N fiber-reinforced resin prefabricated splicing bodies along the inner wall of the oil-cooled motor stator. Each fiber-reinforced resin prefabricated splicing body is spliced with the adjacent fiber-reinforced resin prefabricated splicing body to form one splicing seam. The N fiber-reinforced resin prefabricated splicing bodies are spliced to form N splicing seams, and the size of the spliced N fiber-reinforced resin prefabricated splicing bodies is matched with the size of the inner wall of the oil-cooled motor stator, and it is bonded to the inner wall of the oil-cooled motor stator by using the low viscosity of the resin, where N≥2 and N is a positive integer;

[0017] Step S303: Pressurize and hold the pressure on the inner wall of the oil-cooled motor stator bonded with the fiber-reinforced resin prefabricated splicing body to achieve the pressure fit of the fiber-reinforced resin prefabricated splicing body and the inner wall of the oil-cooled motor stator; perform a curing treatment on the fiber-reinforced resin prefabricated splicing body after it is fitted to the inner wall of the motor stator to obtain the inner wall sealing composite material of the oil-cooled motor stator.

[0018] Optionally, step S200 includes:

[0019] Step B201: Prepare a resin matrix film, and bond the annular fiber reinforcement with the resin matrix film to obtain an annular fiber-reinforced resin preform;

[0020] Step B202: Attach a layer of PE film to the outer surface of the annular fiber-reinforced resin preform and pack it to obtain a packaged annular fiber-reinforced resin preform;

[0021] And / or, step S300 includes:

[0022] Step B301: Take out the annular fiber-reinforced resin preform in the packaged annular fiber-reinforced resin preform and remove the PE film on the outer surface to obtain the annular fiber-reinforced resin preform;

[0023] Step B302: Spread the annular fiber-reinforced resin preform along the inner wall of the oil-cooled motor stator. The size of the annular fiber-reinforced resin preform is matched with the size of the inner wall of the oil-cooled motor stator, and it is bonded to the inner wall of the oil-cooled motor stator by using the low viscosity of the resin matrix;

[0024] Step B303: Pressurize and hold the pressure on the inner wall of the oil-cooled motor stator bonded with the annular fiber-reinforced resin preform to achieve the pressure fit of the annular fiber-reinforced resin preform and the inner wall of the oil-cooled motor stator; perform a curing treatment on the annular fiber-reinforced resin preform after it is fitted to the inner wall of the motor stator to obtain the inner wall sealing composite material of the oil-cooled motor stator.

[0025] Optionally, in step S100, both the planar fiber reinforcement and the annular fiber reinforcement include fabrics. The material of the fabric is one or more of aramid fiber, glass fiber, alumina fiber, silicon carbide fiber, ceramic fiber, polyimide fiber, poly-p-phenylene benzobisoxazole fiber, poly-p-phenylene terephthalamide fiber, polyphenylsulfone amide fiber, polyamideimide fiber, polybenzimidazole fiber, and polytetrafluoroethylene fiber. The material of the resin matrix is one or more of epoxy resin, phenolic resin, unsaturated polyester resin, polyimide resin, urea-formaldehyde resin, and amino resin;

[0026] Optionally, in step S100, the preparation of the planar fiber reinforcement or the annular fiber reinforcement includes: the fabric is treated by a surface modification process to form a fiber reinforcement. The surface modification process includes one or more of plasma process treatment, ultrasonic process treatment, laser process treatment, acid-base process treatment, chemical etching process, coupling agent process treatment, and surface coating modification process; the thickness of the fiber reinforcement is 0.05 - 3 mm, and the diameter of the fiber is 5 - 15 μm.

[0027] Optionally, in step S201, during the padding treatment, the temperature of the resin matrix solution is 20 - 100 °C; the impregnation time of the fiber reinforcement in the resin matrix solution is 1 - 10 min; the padding speed of the padding treatment is 5 - 15 m / min, the padding pressure is 1 - 2000 kPa, the resin matrix content in the prepreg is 20% - 80%, the pre-curing time is 1 - 30 min, and the pre-curing temperature is 50 - 200 °C

[0028] Optionally, in step S300, the pressurization method includes mechanical pressurization. The pressurization pressure of the mechanical pressurization is 1 - 10 Mpa, and the mechanical pressurization method is compression molding; or, the pressurization method includes gas pressurization. The pressurization pressure of the gas pressurization is 1 - 10 Mpa, and the gas pressurization method includes one or more of vacuum bag molding, pneumatic chamber molding, and autoclave molding.

[0029] Optionally, in step S300, the curing treatment adopts a gradient temperature rise curing molding treatment method. The temperature of the curing treatment is 20 - 200 °C, and the curing treatment time is 30 - 200 min.

[0030] In a second aspect, an oil-cooled motor stator inner wall sealing composite material is obtained by using the preparation method of an oil-cooled motor stator inner wall sealing composite material described in any one of the first aspects above.

[0031] Optionally, the oil-cooled motor stator inner wall sealing composite material is formed on the inner wall of the oil-cooled motor stator

[0032] Compared with the prior art, the beneficial effects obtained by the present invention application are as follows:

[0033] (1) In the application of the present invention, the composite material for sealing the inner wall of the oil-cooled motor stator can completely separate the cooling oil circuit from the rotor part, with good sealing effect, which can reduce the resistance and leakage during the flow of the cooling oil, and improve the efficiency and stability of the motor cooling system; while the cooling oil cools the stator core, the end part of the winding and the straight part of the winding, the cooling oil will not drip onto the rotor, avoiding the oil throwing loss of the rotor and having a better cooling effect.

[0034] (2) In the application of the present invention, firstly, the method steps of using the composite material for sealing the inner wall of the oil-cooled motor stator are simple, with fewer processes, easy to control costs and achieve large-scale production, and can be stably adapted to various new energy motors, enabling the mass production of the composite material with the sealing effect of the inner wall of the oil-cooled motor stator; in addition, the structure of the composite material for sealing the inner wall of the oil-cooled motor stator is simple, and the composite molding process has less difficulty, ensuring efficient cooling of the motor. After the heat dissipation of the motor is ensured, a high-power density motor can be designed subsequently, which can reduce the cost of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention application, the following will briefly introduce the drawings required for use in the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0036] Figure 1 It is a schematic diagram of the working principle for preparing the flat fiber-reinforced resin preform of the present invention application;

[0037] Figure 2 It is a schematic diagram of the structure of a composite material for sealing the inner wall of an oil-cooled motor stator of the present invention application Figure 1 ;

[0038] Figure 3 It is a schematic diagram of the structure of a composite material for sealing the inner wall of an oil-cooled motor stator of the present invention application Figure 2 ;

[0039] Figure 4 It is a schematic diagram of the structure of the annular fiber-reinforced body of the present invention application;

[0040] Figure 5 It is a schematic diagram of the structure of the annular fiber-reinforced body, the resin matrix film and the PE film of the present invention application;

[0041] The drawings are used to provide a further understanding of the present invention application, and constitute a part of the specification. Together with the embodiments of the present invention application, they are used to explain the present invention application, and do not constitute a limitation to the present invention application.

[0042] Reference numerals: fiber reinforcement - 11, transmission device - 12, dipping tank - 13, resin matrix solution - 14, oven - 15, fiber - reinforced resin body - 16; release paper - 17, PE film - 18, packaging device - 19, oil - cooled motor stator - 21; wire groove - 22; oil - cooled motor stator inner wall sealing composite material - 23; splicing seam - 31, annular fiber reinforcement - 51; resin matrix film - 52. Detailed implementation manners

[0043] Next, the technical solutions in the embodiments of the present invention application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention application. Obviously, the described embodiments are only a part of the embodiments of the present invention application, rather than all the embodiments; based on the embodiments in the present invention application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present invention application.

[0044] In the description of the present invention application, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation of the present invention.

[0045] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, the meaning of "a plurality" is one or two or more than two, unless otherwise specifically defined.

[0046] In the present invention application, unless otherwise clearly defined and limited, the terms "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrally formed, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0047] To make the purpose, technical solutions and advantages of the present invention application clearer, the embodiments of the present invention application will be further described in detail below in conjunction with the drawings.

[0048] Composite material description

[0049] A composite material is a material composed of two or more materials with different properties, namely a matrix and a reinforcement, which are combined physically or chemically to form a material with new properties at the macroscopic and microscopic levels. The continuously distributed component is called the matrix, such as a polymer (resin) matrix, a metal matrix, or a ceramic matrix; the substances such as fibers, particles, and whiskers dispersed in the matrix are called reinforcements. In a composite material, the various materials exhibit a synergistic effect in terms of performance, making its comprehensive performance superior to the original constituent materials and capable of meeting the requirements of different application scenarios.

[0050] Preparation method description of composite material for sealing the inner wall of the stator of an oil-cooled motor

[0051] As Figures 1 to 2 shown, in a first aspect, a method for preparing a sealing composite material for the inner wall of an oil-cooled motor stator includes:

[0052] Step S100: Obtain a resin matrix and prepare a planar fiber reinforcement or a ring-shaped fiber reinforcement.

[0053] Step S200: Prepare a planar fiber-reinforced resin preform or a ring-shaped fiber-reinforced resin preform, and package the planar fiber-reinforced resin preform or the ring-shaped fiber-reinforced resin preform.

[0054] Step S300: Take the planar fiber-reinforced resin preform from the packaged planar fiber-reinforced resin preform, cut and shape the planar fiber-reinforced resin preform to obtain a fiber-reinforced resin preform splicing body, spread the fiber-reinforced resin preform splicing body along the inner wall of the oil-cooled motor stator, and press the fiber-reinforced resin preform splicing body against the inner wall of the oil-cooled motor stator for bonding; perform a curing treatment on the fiber-reinforced resin preform splicing body after it is bonded to the inner wall of the motor stator to obtain a sealing composite material for the inner wall of the oil-cooled motor stator;

[0055] Or, take the ring-shaped fiber-reinforced resin preform from the packaged ring-shaped fiber-reinforced resin preform, spread the ring-shaped fiber-reinforced resin preform along the inner wall of the oil-cooled motor stator, press the ring-shaped fiber-reinforced resin preform against the inner wall of the oil-cooled motor stator for bonding, and perform a curing treatment on the ring-shaped fiber-reinforced resin preform after it is bonded to the inner wall of the motor stator to obtain a sealing composite material for the inner wall of the oil-cooled motor stator.

[0056] In some embodiments, step S200 includes:

[0057] Step S201: Send the planar fiber reinforcement to a padding device containing a resin matrix solution for padding treatment to obtain a prepreg, and send the prepreg to an oven for pre-curing to obtain a planar fiber-reinforced resin preform;

[0058] Step S202: Attach a release paper to the upper surface of the planar fiber-reinforced resin preform, attach a PE film to the lower surface, and pack it into a roll to obtain a packaged planar fiber-reinforced resin preform;

[0059] In some embodiments, step S300 includes:

[0060] Step S301: Take the packaged planar fiber-reinforced resin preform, remove the release paper on the upper surface and the PE film on the lower surface to obtain the planar fiber-reinforced resin preform, cut and shape the planar fiber-reinforced resin preform to obtain a fiber-reinforced resin preform splicing body;

[0061] Step S302: Spread 1 fiber-reinforced resin preform splicing body along the inner wall of the oil-cooled motor stator. The 1 fiber-reinforced resin preform splicing body is spliced end to end to form 1 splicing seam, and the size of the 1 fiber-reinforced resin preform splicing body is made to match the size of the inner wall of the oil-cooled motor stator, and it is bonded to the inner wall of the oil-cooled motor stator using the low viscosity of the resin; or, spread N fiber-reinforced resin preform splicing bodies along the inner wall of the oil-cooled motor stator. Each fiber-reinforced resin preform splicing body is spliced with the adjacent fiber-reinforced resin preform splicing body to form 1 splicing seam. The N fiber-reinforced resin preform splicing bodies are spliced to form N splicing seams, and the size of the spliced N fiber-reinforced resin preform splicing bodies is made to match the size of the inner wall of the oil-cooled motor stator, and it is bonded to the inner wall of the oil-cooled motor stator using the low viscosity of the resin, where N≥2 and N is a positive integer;

[0062] Step S303: Pressurize and hold the pressure on the inner wall of the oil-cooled motor stator bonded with the fiber-reinforced resin preform splicing body to achieve pressure bonding of the fiber-reinforced resin preform splicing body to the inner wall of the oil-cooled motor stator; perform a curing treatment on the fiber-reinforced resin preform splicing body after it is bonded to the inner wall of the motor stator to obtain a sealing composite material for the inner wall of the oil-cooled motor stator.

[0063] In the method for preparing the inner wall sealing composite material of the oil-cooled motor stator of the present invention application, first, the preparation method uses a fiber-reinforced resin preform and precisely spreads it on the inner wall of the oil-cooled motor stator. By utilizing the low viscosity of the resin and the structural characteristics of the reinforcing fibers, the sealing performance of the inner wall of the stator is ensured. After pressurization and curing, the formed composite material can effectively prevent oil leakage and improve the sealing performance of the motor. Using fiber-reinforced materials not only enhances the structural strength of the composite material but also improves its abrasion resistance and high-temperature resistance, which is particularly suitable for high-load working environments such as oil-cooled motors and helps to appropriately extend the service life of the motor. Additionally, during the splicing process of the fiber-reinforced resin preform, the low viscosity characteristics of the resin and the pressing process are utilized to ensure the sealing and integrity after splicing of single or multiple splicing seams, and the strength at single or multiple splicing seams is also enhanced. The cured composite material has high thermal stability and chemical stability, can withstand high temperature changes and the influence of the external environment during the operation of the motor, and ensures the stable operation of the motor under various complex working conditions. Moreover, the preparation method is not only applicable to oil-cooled motor stators of different sizes and specifications, can flexibly adjust the number and size of the splicing bodies to meet different production requirements, but also the resin matrix and fiber reinforcement materials have good recyclability, having good technical value and market prospects.

[0064] In some embodiments, step S200 includes:

[0065] Step B201: Prepare an annular resin matrix film, and bond the annular fiber reinforcement with the annular resin matrix film to obtain an annular fiber-reinforced resin preform;

[0066] Step B202: Attach a layer of PE film to the outer surface of the annular fiber-reinforced resin preform and pack it to obtain a packaged annular fiber-reinforced resin preform;

[0067] In some embodiments, step S300 includes:

[0068] Step B301: Take the annular fiber-reinforced resin preform in the packaged annular fiber-reinforced resin preform and remove the PE film on the outer surface to obtain an annular fiber-reinforced resin preform;

[0069] Step B302: Spread the annular fiber-reinforced resin preform along the inner wall of the oil-cooled motor stator. The size of the annular fiber-reinforced resin preform matches the size of the inner wall of the oil-cooled motor stator, and it is adhered to the inner wall of the oil-cooled motor stator by utilizing the low viscosity of the resin matrix;

[0070] Step B303: Pressurize and hold pressure on the inner wall of the oil-cooled motor stator adhered with the annular fiber-reinforced resin preform to achieve the pressure-bonding of the annular fiber-reinforced resin preform with the inner wall of the oil-cooled motor stator; perform a curing treatment on the annular fiber-reinforced resin preform after it is bonded to the inner wall of the motor stator to obtain the oil-cooled motor stator inner wall sealing composite material.

[0071] Similarly, in the method for preparing the oil-cooled motor stator inner wall sealing composite material of the present invention application, first, the preparation method uses a fiber-reinforced resin preform and precisely spreads it on the inner wall of the oil-cooled motor stator. By utilizing the low viscosity of the resin and the structural characteristics of the reinforcing fibers, the sealing performance of the stator inner wall is ensured. After pressurization and curing, the formed composite material can effectively prevent oil leakage and improve the sealing performance of the motor. Using fiber-reinforced materials not only enhances the structural strength of the composite material but also improves its anti-wear and high-temperature resistance capabilities, which is particularly suitable for high-load working environments such as oil-cooled motors and helps to appropriately extend the service life of the motor; in addition, an annular fiber-reinforced resin body and an annular resin matrix film can be integrally formed, ensuring the independence and integrity of the annular fiber-reinforced resin body and the annular resin matrix. The preparation method is not only applicable to oil-cooled motor stators of different sizes and specifications, can flexibly adjust the number and size of the splicing bodies to meet different production requirements, and the resin matrix and fiber-reinforced body materials have good recyclability, and also have good technical value and market prospects.

[0072] Optionally, in step S100, the planar fiber-reinforced body and the annular fiber-reinforced body both include fabrics, and the material of the fabric is one or more of aramid fiber, glass fiber, alumina fiber, silicon carbide fiber, ceramic fiber, polyimide fiber, poly(p-phenylene benzobisoxazole) fiber, poly(p-phenylene terephthalamide) fiber, polyphenylsulfone amide fiber, polyamide-imide fiber, polybenzimidazole fiber, and polytetrafluoroethylene fiber, and the material of the resin matrix is one or more of epoxy resin, phenolic resin, unsaturated polyester resin, polyimide resin, urea-formaldehyde resin, and amino resin.

[0073] In some embodiments, using multiple types of reinforcing fibers (such as aramid fiber, glass fiber, silicon carbide fiber, etc.) can select the best material combination according to different requirements. For example, aramid fiber has excellent tensile resistance and impact resistance, while glass fiber provides higher strength and stiffness. By reasonably combining the advantages of different fibers, the performance of the composite material can be optimized to meet the requirements under different usage conditions.

[0074] In some embodiments, the use of high-temperature materials such as polyimide fibers, polytetrafluoroethylene fibers, and alumina fibers can significantly improve the high-temperature resistance and chemical corrosion resistance of the composite material, enabling the composite material to be applicable to high-temperature environments or occasions exposed to corrosive media, such as the stator sealing layer of an oil-cooled motor, and extending its service life and reliability.

[0075] In some embodiments, in the selection of reinforcing fibers, fibers such as silicon carbide fibers and polyamide fibers have high strength, rigidity, and wear resistance, and can enhance the tensile strength, compressive strength, and fatigue resistance of the composite material. At the same time, resin matrix materials such as epoxy resin, phenolic resin, and unsaturated polyester resin not only have good adhesion properties, but also have excellent mechanical properties, chemical corrosion resistance, and heat resistance. By combining different resin materials, the properties of the composite material can be optimized. For example, epoxy resin has high rigidity and heat resistance and is suitable for applications in high-temperature environments, thus ensuring the overall firmness and durability of the composite material, and improving the sealing performance and mechanical strength of the inner wall of the motor stator.

[0076] In some embodiments, the fabric can include woven fabric, knitted fabric, non-woven fabric, and braided fabric, and has good processability. Flexible materials such as knitted fabric and braided fabric can be more easily formed to adapt to complex structures and surface conformities; non-woven fabric can provide a uniform fiber distribution and enhance the performance stability of the composite material. The diversity of these materials provides greater flexibility to adapt to different processing techniques and application requirements.

[0077] Thus, in the present invention application, the use of a variety of fiber materials and resin matrices not only has superior performance, but also has good recyclability and environmental friendliness. The composite material is lighter in weight, reduces production costs, and at the same time does not lose its high-efficiency sealing function. The combination of fibers and resins can be adjusted according to needs to adapt to different types of motors and working environments.

[0078] Optionally, in step S100, the preparation of the planar fiber reinforcement and the annular fiber reinforcement both include: the fabric is treated by a surface modification process to form a fiber reinforcement, and the surface modification process includes one or more of a plasma process, an ultrasonic process, a laser process, an acid-base process, a chemical etching process, a coupling agent process, and a surface coating modification process; the thickness of the fiber reinforcement is 0.05 - 3 mm, and the diameter of the fiber is 5 - 15 μm.

[0079] In some embodiments, surface modification methods such as plasma process and chemical etching can change the chemical composition and microstructure of the fiber surface, thereby enhancing its adhesion to the resin matrix. This enhanced interfacial bonding force significantly improves the mechanical properties, durability, and impact resistance of the composite material.

[0080] In some embodiments, ultrasonic processes, laser processes, etc. can finely adjust the structure of the fiber surface to make it more hydrophilic or oleophilic, and the surface properties can be customized according to actual needs. This treatment improves the interfacial compatibility between the fiber and the resin, reduces delamination or peeling phenomena, and thus ensures the stability of the composite material; the coupling agent process can improve the compatibility between different fibers and the resin matrix and is applicable to a wide range of fiber and resin combinations; the acid-base process treatment can enhance the surface activity of the fiber and improve its affinity for the resin.

[0081] In the application of the present invention, the fiber reinforcement can adopt a planar structure or a tubular (i.e., annular) structure design, so that the fiber reinforcement can adapt to products with different shape and structure requirements. This flexible structure design can meet the customization requirements of various complex structures, especially for the application of the sealing material on the inner wall of the stator of an oil-cooled motor; at the same time, the surface-modified fiber reinforcement has better mechanical properties, such as tensile strength, bending strength, etc., and has excellent anti-aging and anti-corrosion properties. This greatly enhances the stability and durability of the composite material in harsh environments and is especially suitable for applications with strict requirements such as the stator of an oil-cooled motor.

[0082] Optionally, in step S201, during the padding treatment, the temperature of the resin matrix solution is 20 - 100 °C; the impregnation time of the fiber reinforcement in the resin matrix solution is 1 - 10 min; the padding speed of the padding treatment is 5 - 15 m / min, the padding pressure is 1 - 2000 kPa, the resin matrix content in the prepreg is 20 - 80%, the pre-curing time is 1 - 30 min, and the pre-curing temperature is 50 - 200 °C.

[0083] In some embodiments, the impregnation and rolling treatment is a process for composite material manufacturing. Mainly, the fiber reinforcement 11 is immersed in the resin matrix solution 14 through an impregnation device, and the excess resin is removed through a rolling process, enabling the fiber reinforcement to be evenly wetted in the resin, thereby obtaining a prepreg. The impregnation device generally includes an immersion tank 13, rolling rollers, a transmission device 12, a frame, etc. The immersion tank 13 is used to hold the resin matrix solution, and its shape and size are designed according to production requirements; the rolling rollers are key components, usually including hard rolling rollers and soft rolling rollers. By adjusting the pressure between the hard rolling rollers and the soft rolling rollers, the content of the resin matrix solution on the fiber reinforcement is controlled. The materials and surface characteristics of the hard rolling rollers and the soft rolling rollers also affect the impregnation and rolling effect; the transmission device is used to drive the fiber reinforcement to run in the impregnation device, ensuring the continuity of the impregnation and rolling process treatment. The steps of the impregnation and rolling treatment generally include: 1) Resin matrix impregnation. The reinforcing fibers (such as glass fibers, carbon fibers, etc.) are immersed in the resin matrix solution, enabling the resin matrix to fully penetrate into the voids of the fiber reinforcement; 2) Rolling to remove excess resin. The impregnated fiber reinforcement is fed into the rolling rollers, and under the action of the rolling rollers, the excess resin in the fibers is removed, ensuring precise control of the resin content. The ratio of the rolled fiber reinforcement to the resin is appropriate, achieving the expected physical and chemical properties; 3) Forming a prepreg. A prepreg is obtained through this process, with a uniform resin matrix content and distribution, preparing for subsequent curing or molding processes. Thus, through the impregnation and rolling treatment, the fiber reinforcement is immersed in the resin matrix solution, ensuring that the resin can evenly penetrate into the voids of the fibers. This step can efficiently enable the resin to fully penetrate the fibers and ensure that the surface and internal structures of the fibers are fully wetted, contributing to improving the bonding strength between the fibers and the resin matrix;

[0084] In some embodiments, multiple parameters of the impregnation and rolling treatment process (such as temperature, impregnation time, impregnation and rolling speed, impregnation and rolling pressure, etc.) can be adjusted according to different production requirements. For example, the control of the impregnation time (1 - 10 min) and temperature (20 - 100 °C) can be optimized according to the characteristics of the resin and the type of fiber, ensuring the flexibility of the process and the stability of the product. By adjusting the impregnation and rolling speed (5 - 15 m / min) and pressure (1 - 2000 kPa), the penetration depth of the resin and the impregnation degree of the fiber reinforcement can be controlled, thereby optimizing the properties of the composite material.

[0085] In the present invention application, first, after the fiber reinforcement is impregnated with resin, a good fiber / resin interface can be formed, improving the adhesion, tensile strength and fatigue resistance of the composite material. During the impregnation and rolling process, the compatibility between the resin and the fiber is enhanced, making the finally prepared composite material have better mechanical properties, especially showing more excellent performance under stress conditions; in addition, the rolling step can not only remove the excess resin, but also ensure that the resin is more evenly distributed in the fiber reinforcement. The resin content and distribution uniformity in the prepreg directly affect the stability of the subsequent forming process and the final properties of the composite material. By precisely controlling the impregnation and rolling pressure and the settings of the rollers, high consistency in the mechanical properties, thermal properties, etc. of the composite material can be ensured. The resin content of the final prepreg is precisely controlled within the range of 20%-80%, laying a solid foundation for the subsequent curing; in addition, the curing step (such as pre-curing for 1-30 minutes at 50-200 °C) can prepare for the final curing of the composite material, ensuring the structural integrity and high performance of the composite material after forming.

[0086] In some embodiments, after the prepreg is sent into the oven 15 for pre-curing, a fiber-reinforced resin preform 16 is obtained. A release paper 17 is attached to the upper surface of the fiber-reinforced resin preform, and a PE film 18 is attached to the lower surface. It is packed into a roll by a packaging device 19 to obtain a packaged fiber-reinforced resin preform. Exemplarily, the device 19 can be a conventional winding device (including a winding drum, etc.).

[0087] In some embodiments, in step S300, the size matching of one fiber-reinforced resin prefabricated splicing body with the inner wall of the oil-cooled motor stator includes: according to the circumference and height of the inner wall of the stator core, making the length of the size of one fiber-reinforced resin prefabricated splicing body match the circumference of the inner wall of the stator core, and the width of the size of one fiber-reinforced resin prefabricated splicing body equal to the height of the inner wall of the stator core, so that one fiber-reinforced resin prefabricated splicing body can be spread along the inner wall of the oil-cooled motor stator; or, the size matching of N fiber-reinforced resin prefabricated splicing bodies after splicing with the inner wall of the oil-cooled motor stator includes: according to the circumference and height of the inner wall of the stator core, making the length of the N fiber-reinforced resin prefabricated splicing bodies after splicing match the circumference of the inner wall of the stator core, and the width of the size of each fiber-reinforced resin prefabricated splicing body equal to the height of the inner wall of the stator core, so that N fiber-reinforced resin prefabricated splicing bodies can be spread along the inner wall of the oil-cooled motor stator.

[0088] In the application of the present invention, firstly, by ensuring that the length of one or N fiber-reinforced resin prefabricated splicing bodies after splicing matches the circumference of the inner wall of the stator core, and the width of each fiber-reinforced resin prefabricated splicing body is equal to the height of the inner wall of the stator core, the stability of the splicing body can be ensured, and the strength and structural integrity of the inner wall of the stator can be effectively improved. Each splicing body can be evenly distributed on the inner wall of the stator, ensuring good adhesion between the composite material and the inner wall of the stator, avoiding waste during the spreading process of the composite material, reducing unnecessary production costs, maximizing the material utilization rate, and ensuring high-quality composite material production at the same time. Additionally, the precise size matching enables the fiber-reinforced resin prefabricated splicing body to effectively adhere to the surface of the inner wall of the oil-cooled motor stator. The resin matrix can form a good bonding interface between the reinforcing fiber and the inner wall of the stator core, ensuring the sealing and integrity of the single or multiple splicing seams after splicing, enhancing the overall mechanical properties and sealing performance of the composite material, and providing the stability and durability for the long-term operation of the composite material. Furthermore, by utilizing the low-viscosity characteristic of the resin and the pressing process, the sealing and integrity of the single or multiple splicing seams after splicing can be ensured. This can not only meet the size requirements of the standard stator inner wall but also be customized and adjusted according to the motor stators of different models and specifications, enabling this process to be widely applied to the manufacturing of the inner walls of various oil-cooled motor stators to meet different production requirements.

[0089] Optionally, in step S300, the pressurization method includes mechanical pressurization. The pressurization pressure of mechanical pressurization is 1 - 10 Mpa, and the mechanical pressurization method is molding by pressing; or, the pressurization method includes gas pressurization. The pressurization pressure of gas pressurization is 1 - 10 Mpa, and the gas pressurization methods include one or more of vacuum bag molding, pneumatic chamber molding, and autoclave molding.

[0090] In the application of the present invention, firstly, in terms of the pressurization method, mechanical pressurization adopts molding by pressing, which can provide a stable pressure of 1 - 10 Mpa to ensure the tight adhesion between the fiber-reinforced resin prefabricated splicing body and the inner wall of the stator. The gas pressurization methods are diverse, such as vacuum bag molding, pneumatic chamber molding, autoclave molding, etc., which can be flexibly selected according to different requirements, and can also ensure a pressure range of 1 - 10 Mpa. These pressurization methods can significantly enhance the sealing effect, firmly bond the composite material to the inner wall of the stator, and the diverse pressurization methods improve the flexibility of the preparation process and adapt to production of different scales and requirements. Additionally, different molding methods help control the performance of the composite material, optimize its internal structure, enable it to have better sealing performance and strength, effectively prevent oil leakage, extend the service life of the oil-cooled motor, and provide a reliable guarantee for the stable operation of the motor.

[0091] Optionally, in step S300, the curing treatment adopts a gradient temperature curing and forming treatment method. The temperature of the curing treatment is 20 - 200 °C, and the curing treatment time is 30 - 200 min.

[0092] In the application of the present invention, first of all, through gradient heating, the curing process can be smoother and more controllable. The gradual change of temperature during the curing process enables the curing reaction of the resin matrix to be more complete. The molecular structure of the resin can be crosslinked uniformly, enhancing the adhesion between the reinforcing fibers and the resin matrix, improving the curing quality of the composite material for sealing the inner wall of the oil-cooled motor stator, and enhancing the physical properties, mechanical properties and heat resistance of the composite material. Thus, the service life and working reliability of the composite material for sealing the inner wall of the oil-cooled motor stator are improved. In addition, the gradient heating during the curing process enables flexible adjustment within a wide temperature range. The curing temperature (20°C to 200°C) and curing time (30 to 200 minutes) can be precisely optimized according to the requirements of different resin matrices and the characteristics of fiber materials, and can be flexibly applied to different types of resin materials (such as epoxy resin, phenolic resin, etc.) and reinforcing fiber types, meeting the curing requirements of various products for the inner wall of the oil-cooled motor stator.

[0093] Composite material description for sealing the inner wall of the stator of an oil-cooled motor

[0094] Such as Figure 2 、 Figure 3 、 Figure 5 As shown, on the second aspect, a composite material for sealing the inner wall of an oil-cooled motor stator is obtained by using any one of the methods for preparing a composite material for sealing the inner wall of an oil-cooled motor stator in the first aspect, and the composite material for sealing the inner wall of the oil-cooled motor stator is formed on the inner wall of the oil-cooled motor stator.

[0095] In the application of the present invention, the oil-cooled motor stator 21 includes a plurality of wire grooves 22. The composite material for sealing the inner wall of the oil-cooled motor stator 23 is formed on the inner wall of the oil-cooled motor stator. The composite material for sealing the inner wall of the oil-cooled motor stator can completely separate the cooling oil circuit from the rotor part, with good sealing effect, reducing the resistance and leakage during the flow of the cooling oil, and improving the efficiency and stability of the motor cooling system. While the cooling oil cools the stator core, the end part of the winding and the straight part of the winding, the cooling oil will not drip onto the rotor, avoiding the oil throwing loss of the rotor, and having a better cooling effect. The composite material for sealing the inner wall of the oil-cooled motor stator has a simple structure and a relatively small difficulty in the composite molding process, ensuring efficient cooling of the motor. After ensuring the heat dissipation of the motor, a high-power density motor can be designed subsequently, which can reduce the cost of the motor.

[0096] Exemplary description of composite material for sealing the inner wall of the stator of an oil-cooled motor

[0097] (1) A method for preparing a composite material for sealing the inner wall of an oil-cooled motor stator, comprising:

[0098] Step S100: Obtain a resin matrix and prepare a planar fiber reinforcement;

[0099] In some embodiments, step S100 may be step SA100. In step SA100, a polyimide resin matrix is obtained, and a planar aramid fiber reinforcement is obtained. The thickness of the planar aramid fiber reinforcement is 0.2 mm. The planar aramid fiber reinforcement includes an aramid fiber non-woven fabric (i.e., the aramid fiber non-woven fabric serves as the fabric of the aramid fiber reinforcement). The surface of the aramid fiber non-woven fabric is subjected to a plasma process treatment, for example, an oxygen plasma process treatment. The time of the plasma process treatment is 10 min, and the discharge power is 400 W.

[0100] In some embodiments, step S100 may be step SB100. In step SB100, an epoxy resin matrix is obtained, and a planar aramid fiber reinforcement is obtained. The thickness of the planar aramid fiber reinforcement is 0.06 - 0.1 mm. The planar aramid fiber reinforcement includes an aramid fiber woven fabric (i.e., the aramid fiber woven fabric serves as the fabric of the aramid fiber reinforcement). The aramid fiber woven fabric includes a plain weave structure. The aramid fiber woven fabric is subjected to a chemical etching process treatment. For example, the surface of the aramid fiber woven fabric is subjected to a 5 - 30 min chemical etching process treatment using a KOH solution with a concentration of 10% - 40%.

[0101] In some embodiments, step S100 may be step SC100. In step SC100, a phenolic resin matrix is obtained, and a planar glass fiber reinforcement is obtained. The thickness of the planar glass fiber reinforcement is 0.2 mm. The planar glass fiber reinforcement includes a glass fiber woven fabric (i.e., the aramid fiber woven fabric serves as the fabric of the aramid fiber reinforcement). The glass fiber woven fabric is subjected to a coupling agent process treatment. For example, the surface of the glass fiber woven fabric is subjected to a 10 - 30 min silane coupling agent process treatment using a silane coupling agent solution with a concentration of 0.5% - 2.0%.

[0102] Step S200: Prepare a planar fiber-reinforced resin preform and package the planar fiber-reinforced resin preform; specifically, step S200 includes:

[0103] Step S201: Send the planar fiber reinforcement to a padding device containing a resin matrix solution for padding treatment to obtain a prepreg, and the prepreg is sent to an oven for pre-curing to obtain a planar fiber-reinforced resin preform;

[0104] In some embodiments, step S200 may be step SA200, step S201 may be step SA201, step S202 may be step SA202, and step SA200 includes step SA201 and step SA202. In step SA201, a planar aramid fiber reinforcement is sent into a padding device containing a polyimide resin matrix solution for padding treatment. During the padding treatment, the temperature of the polyimide resin matrix solution is maintained at 60°C, the impregnation time of the aramid fiber reinforcement in the polyimide resin matrix solution is 2 min, the padding speed of the padding treatment is 5 min, and the padding pressure is 1000 kPa. Exemplarily, the impregnated planar aramid fiber reinforcement is sent into a roller, and under the action of the roller, the excess polyimide resin in the fiber is removed to obtain a prepreg. The content of the polyimide resin matrix in the prepreg is 40%. The prepreg is sent into an oven for pre-curing to obtain a planar aramid fiber reinforced resin preform. The pre-curing time is 30 min, and the pre-curing temperature is 150°C.

[0105] In some embodiments, step S200 may be step SB200, step S201 may be step SB201, step S202 may be step SB202, and step SB200 includes step SB201 and step SB202. In step SB201, a planar aramid fiber reinforcement is sent into a padding device containing an epoxy resin matrix solution for padding treatment. During the padding treatment, the temperature of the epoxy resin matrix solution is maintained at 50°C, the impregnation time of the planar aramid fiber reinforcement in the epoxy resin matrix solution is 3 min, the padding speed of the padding treatment is 10 min, and the padding pressure is 1500 kPa. Exemplarily, the impregnated planar aramid fiber reinforcement is sent into a roller, and under the action of the roller, the excess epoxy resin in the fiber is removed to obtain a prepreg. The content of the epoxy resin matrix in the prepreg is 40%. The prepreg is sent into an oven for pre-curing to obtain a planar aramid fiber reinforced resin preform. The pre-curing time is 20 min, and the pre-curing temperature is 100°C.

[0106] In some embodiments, step S200 may be step SC200, step S201 may be step SC201, step S202 may be step SC202, and step SC200 includes step SC201 and step SC202. In step SC201, a planar glass fiber reinforced body is sent into a padding device containing a phenolic resin matrix solution for padding treatment. During the padding treatment, the temperature of the phenolic resin matrix solution is maintained at 80 °C, the impregnation time of the planar glass fiber reinforced body in the phenolic resin matrix solution is 5 min, the padding speed of the padding treatment is 5 min, and the padding pressure is 2000 kPa. Exemplarily, the impregnated planar glass fiber reinforced body is sent into a roller, and under the action of the roller, the excess phenolic resin in the fiber is removed to obtain a prepreg. The content of the polyimide resin matrix in the prepreg is 38%. The prepreg is sent into an oven for pre-curing to obtain a planar glass fiber reinforced resin preform. The pre-curing time is 60 min, and the pre-curing temperature is 100 °C.

[0107] Step S202: Attach a release paper to the upper surface of the planar fiber reinforced resin preform, attach a PE film to the lower surface, and pack it into a roll to obtain a packaged planar fiber reinforced resin preform;

[0108] In some embodiments, step S202 may be step SA202. In step SA202, when the planar aramid fiber reinforced resin preform includes an aramid fiber reinforced body and a polyimide resin matrix, attach a release paper to the upper surface of the planar aramid fiber reinforced resin preform, attach a PE film to the lower surface, and pack it into a roll to obtain a packaged planar fiber reinforced resin preform;

[0109] In some embodiments, step S202 may be step SB202. In step SB202, when the planar aramid fiber reinforced resin preform includes an aramid fiber reinforced body and an epoxy resin matrix, attach a release paper to the upper surface of the planar aramid fiber reinforced resin preform, attach a PE film to the lower surface, and pack it into a roll to obtain a packaged planar fiber reinforced resin preform;

[0110] In some embodiments, step S202 may be step SC202. In step SC202, when the planar glass fiber reinforced resin preform includes a glass fiber reinforced body and a phenolic resin matrix, attach a release paper to the upper surface of the planar aramid fiber reinforced resin preform, attach a PE film to the lower surface, and pack it into a roll to obtain a packaged planar fiber reinforced resin preform;

[0111] Step S300: Take the planar fiber-reinforced resin preform in the packaged planar fiber-reinforced resin preform, cut and shape the planar fiber-reinforced resin preform to obtain a fiber-reinforced resin preform splicing body, spread the fiber-reinforced resin preform splicing body along the inner wall of the oil-cooled motor stator, and press and fit the fiber-reinforced resin preform splicing body with the inner wall of the oil-cooled motor stator; cure the fiber-reinforced resin preform splicing body after fitting with the inner wall of the motor stator to obtain a sealing composite material for the inner wall of the oil-cooled motor stator. Specifically, step S300 includes:

[0112] Step S301: Take the packaged planar fiber-reinforced resin preform, remove the release paper on the upper surface and the PE film on the lower surface to obtain the planar fiber-reinforced resin preform, cut and shape the planar fiber-reinforced resin preform to obtain a fiber-reinforced resin preform splicing body;

[0113] In some embodiments, step S300 may be step SA300, step S301 may be step SA301, step S302 may be step SA302, step S303 may be step SA303, and step SA300 includes step SA301, step SA302, and step SA303. In step SA301, take the packaged planar aramid fiber-reinforced resin preform, remove the release paper on the upper surface and the PE film on the lower surface to obtain the planar aramid fiber-reinforced resin preform, and perform laser cutting and shaping on the planar aramid fiber-reinforced resin preform to obtain an aramid fiber-reinforced resin preform splicing body.

[0114] In some embodiments, step S300 may be step SB300, step S301 may be step SB301, step S302 may be step SB302, step S303 may be step SB303, and step SB300 includes step SB301, step SB302, and step SB303. In step SB301, take the packaged planar aramid fiber-reinforced resin preform, remove the release paper on the upper surface and the PE film on the lower surface to obtain the aramid fiber-reinforced resin preform, and perform numerical control cutting and shaping on the aramid fiber-reinforced resin preform to obtain an aramid fiber-reinforced resin preform splicing body.

[0115] In some embodiments, step S300 may be step SC300, step S301 may be step SC301, step S302 may be step SC302, step S303 may be step SC303, and step SC300 includes step SC301, step SC302, and step SC303. In step SC301, take the packaged planar glass fiber-reinforced resin preform, remove the release paper on the upper surface and the PE film on the lower surface to obtain the glass fiber-reinforced resin preform, and perform mechanical cutting and shaping on the glass fiber-reinforced resin preform to obtain a glass fiber-reinforced resin preform splicing body.

[0116] Step S302: Spread one fiber-reinforced resin prefabricated splicing body along the inner wall of the oil-cooled motor stator. One fiber-reinforced resin prefabricated splicing body is spliced end to end to form one splicing seam, and the size of one fiber-reinforced resin prefabricated splicing body is matched with the size of the inner wall of the oil-cooled motor stator, and it is bonded to the inner wall of the oil-cooled motor stator by using the low viscosity of the resin; or, spread N fiber-reinforced resin prefabricated splicing bodies along the inner wall of the oil-cooled motor stator. Each fiber-reinforced resin prefabricated splicing body is spliced with the adjacent fiber-reinforced resin prefabricated splicing body to form one splicing seam. N fiber-reinforced resin prefabricated splicing bodies are spliced to form N splicing seams, and the size of the spliced N fiber-reinforced resin prefabricated splicing bodies is matched with the size of the inner wall of the oil-cooled motor stator, and it is bonded to the inner wall of the oil-cooled motor stator by using the low viscosity of the resin, N≥2, and N is a positive integer;

[0117] In some embodiments, step S302 may be step SA302. In step SA302, spread one aramid fiber-reinforced resin prefabricated splicing body along the inner wall of the oil-cooled motor stator. One aramid fiber-reinforced resin prefabricated splicing body is spliced end to end to form one splicing seam, and the size of one aramid fiber-reinforced resin prefabricated splicing body is matched with the size of the inner wall of the oil-cooled motor stator, and it is bonded to the inner wall of the oil-cooled motor stator by using the low viscosity of the polyimide resin; or, spread N aramid fiber-reinforced resin prefabricated splicing bodies along the inner wall of the oil-cooled motor stator. Each aramid fiber-reinforced resin prefabricated splicing body is spliced with the adjacent aramid fiber-reinforced resin prefabricated splicing body to form one splicing seam. N aramid fiber-reinforced resin prefabricated splicing bodies are spliced to form N splicing seams, and the size of the spliced N aramid fiber-reinforced resin prefabricated splicing bodies is matched with the size of the inner wall of the oil-cooled motor stator, and it is bonded to the inner wall of the oil-cooled motor stator by using the low viscosity of the polyimide resin, N≥2, and N is a positive integer;

[0118] In some embodiments, step S302 may be step SB302. In step SB302, spread one aramid fiber-reinforced resin prefabricated splicing body along the inner wall of the oil-cooled motor stator. One aramid fiber-reinforced resin prefabricated splicing body is spliced end to end to form one splicing seam, and the size of one aramid fiber-reinforced resin prefabricated splicing body is matched with the size of the inner wall of the oil-cooled motor stator, and it is bonded to the inner wall of the oil-cooled motor stator by using the low viscosity of the epoxy resin; or, spread N aramid fiber-reinforced resin prefabricated splicing bodies along the inner wall of the oil-cooled motor stator. Each aramid fiber-reinforced resin prefabricated splicing body is spliced with the adjacent aramid fiber-reinforced resin prefabricated splicing body to form one splicing seam. N aramid fiber-reinforced resin prefabricated splicing bodies are spliced to form N splicing seams, and the size of the spliced N aramid fiber-reinforced resin prefabricated splicing bodies is matched with the size of the inner wall of the oil-cooled motor stator, and it is bonded to the inner wall of the oil-cooled motor stator by using the low viscosity of the epoxy resin, N≥2, and N is a positive integer;

[0119] In some embodiments, step S302 may be step SC302. In step SC302, one fiberglass-reinforced resin prefabricated splicing body is spread along the inner wall of the oil-cooled motor stator. One fiberglass-reinforced resin prefabricated splicing body is spliced end to end to form one splicing seam, and the size of one fiberglass-reinforced resin prefabricated splicing body is matched with the size of the inner wall of the oil-cooled motor stator, and it is bonded to the inner wall of the oil-cooled motor stator by using the low viscosity of phenolic resin; or, N fiberglass-reinforced resin prefabricated splicing bodies are spread along the inner wall of the oil-cooled motor stator. Each fiberglass-reinforced resin prefabricated splicing body is spliced with the adjacent fiberglass-reinforced resin prefabricated splicing body to form one splicing seam. N fiberglass-reinforced resin prefabricated splicing bodies are spliced to form N splicing seams, and the size of the spliced N fiberglass-reinforced resin prefabricated splicing bodies is matched with the size of the inner wall of the oil-cooled motor stator, and it is bonded to the inner wall of the oil-cooled motor stator by using the low viscosity of phenolic resin, where N≥2 and N is a positive integer;

[0120] Step S303: Pressurize and hold the pressure on the inner wall of the oil-cooled motor stator bonded with the fiber-reinforced resin prefabricated splicing body to achieve the pressurized fitting of the fiber-reinforced resin prefabricated splicing body and the inner wall of the oil-cooled motor stator; perform a curing treatment on the fiber-reinforced resin prefabricated splicing body after it is fitted to the inner wall of the motor stator to obtain a sealing composite material for the inner wall of the oil-cooled motor stator;

[0121] In some embodiments, step S303 may be step SA303. In step SA303, pressurize and hold the pressure on the inner wall of the oil-cooled motor stator bonded with the aramid fiber-reinforced resin prefabricated splicing body to achieve the pressurized fitting of the fiber-reinforced resin prefabricated splicing body and the inner wall of the oil-cooled motor stator. The gas pressurization method of autoclave molding is adopted, and the pressurization pressure is 4 Mpa, and the pressure is continuously held until the composite material is cured and formed; perform a curing treatment on the fiber-reinforced resin prefabricated splicing body after it is fitted to the inner wall of the motor stator. The curing treatment adopts a gradient temperature rise curing and forming treatment method: the curing time is 60 min under the temperature condition of 150 °C, and then it is raised to 200 °C and cured for 120 min to obtain a sealing composite material for the inner wall of the oil-cooled motor stator;

[0122] In some embodiments, step S303 may be step SB303. In step SB303, pressurize and hold the pressure on the inner wall of the oil-cooled motor stator bonded with the aramid fiber-reinforced resin prefabricated splicing body to achieve the pressurized fitting of the aramid fiber-reinforced resin prefabricated splicing body and the inner wall of the oil-cooled motor stator. The mechanical pressurization method of compression molding is adopted, and the pressurization pressure is 3 Mpa, and the pressure is continuously held until the composite material is cured and formed; perform a curing treatment on the fiber-reinforced resin prefabricated splicing body after it is fitted to the inner wall of the motor stator. The curing treatment adopts a gradient temperature rise curing and forming treatment method: the curing time is 30 min under the temperature condition of 90 °C, and then it is raised to 150 °C and cured for 120 min to obtain a sealing composite material for the inner wall of the oil-cooled motor stator;

[0123] In some embodiments, step S303 may be step SC303. In step SC303, the inner wall of the oil-cooled motor stator bonded with the glass fiber reinforced resin prefabricated splicing body is pressurized and kept under pressure to achieve the pressure bonding of the glass fiber reinforced resin prefabricated splicing body with the inner wall of the oil-cooled motor stator. The mechanical pressurization method of molding pressing is adopted, and the pressurization pressure is 3 Mpa. The pressure is kept until the composite material is cured and formed. The fiber reinforced resin prefabricated splicing body after being bonded to the inner wall of the motor stator is cured. The curing treatment adopts the gradient temperature rising curing forming treatment method: curing time is 60 min under the temperature condition of 90 °C, and then it is raised to 200 °C and cured for 120 min to obtain the sealing composite material for the inner wall of the oil-cooled motor stator.

[0124] In some embodiments, a method for preparing a sealing composite material for the inner wall of an oil-cooled motor stator may include step SA100, step SA200, and step SA300, and then the sealing composite material A for the inner wall of the oil-cooled motor stator can be prepared.

[0125] In some embodiments, a method for preparing a sealing composite material for the inner wall of an oil-cooled motor stator may include step SB100, step SB200, and step SB300, and then the sealing composite material B for the inner wall of the oil-cooled motor stator can be prepared.

[0126] In some embodiments, a method for preparing a sealing composite material for the inner wall of an oil-cooled motor stator may include step SC100, step SC200, and step SC300, and then the sealing composite material C for the inner wall of the oil-cooled motor stator can be prepared.

[0127] (2) A method for preparing a sealing composite material for the inner wall of an oil-cooled motor stator includes:

[0128] Step SD100: Obtain a resin matrix and prepare an annular fiber reinforcement 51;

[0129] In some embodiments, step SD100 includes:

[0130] Obtain an epoxy resin matrix and prepare an annular glass fiber reinforcement. The annular glass fiber reinforcement includes an annular glass fiber fabric. Use a cylindrical weaving machine to prepare the annular glass fiber fabric. Treat the annular glass fiber fabric with a silane coupling agent solution with a concentration of 0.5%-2.0% for a treatment time of 10-30 min to prepare the annular glass fiber reinforcement. As Figure 4 shown, the annular glass fiber reinforcement is seamless. The outer diameter of the annular glass fiber reinforcement is basically the same as the diameter size of the inner wall of the iron core. The radial thickness range of the annular glass fiber reinforcement is 0.2 mm - 1 mm;

[0131] Step SD200 includes:

[0132] Step SD201: Prepare the resin matrix film 52, bond the annular fiber reinforcement with the resin matrix film to obtain an annular fiber-reinforced resin preform;

[0133] In some embodiments, step SD201 includes: mixing the epoxy resin matrix and the curing agent in proportion, heating to 80 - 100 °C for partial curing reaction to form a prepolymer. After the prepolymer is cooled, it enters a calender to form a film with a thickness of 0.2 - 1 mm. Bond the annular glass fiber reinforcement with the resin matrix film to obtain an annular glass fiber-reinforced resin preform.

[0134] In some embodiments, step SD202 includes: attaching a layer of PE film to the outer surface of the annular glass fiber-reinforced resin preform and packing it to obtain a packed annular glass fiber-reinforced resin preform;

[0135] Step SD300 includes: taking the annular fiber-reinforced resin preform in the packed annular fiber-reinforced resin preform, spreading the annular fiber-reinforced resin preform along the inner wall of the oil-cooled motor stator, pressing and bonding the annular fiber-reinforced resin preform with the inner wall of the oil-cooled motor stator, and curing the annular fiber-reinforced resin preform after bonding with the inner wall of the motor stator to obtain a sealing composite material for the inner wall of the oil-cooled motor stator.

[0136] In some embodiments, step SD300 includes:

[0137] Step SD301: Take the annular glass fiber-reinforced resin preform in the packed annular glass fiber-reinforced resin preform and remove the PE film on the outer surface to obtain an annular glass fiber-reinforced resin preform;

[0138] Step SD302: Spread the annular glass fiber-reinforced resin preform along the inner wall of the oil-cooled motor stator. The size of the annular glass fiber-reinforced resin preform matches the size of the inner wall of the oil-cooled motor stator, and bond it with the inner wall of the oil-cooled motor stator using the low viscosity of the resin matrix;

[0139] Step SD303: Pressurize and hold the pressure on the inner wall of the oil-cooled motor stator bonded with the annular glass fiber-reinforced resin preform to achieve the pressure bonding of the annular glass fiber-reinforced resin preform with the inner wall of the oil-cooled motor stator; cure the annular glass fiber-reinforced resin preform after bonding with the inner wall of the motor stator to obtain a sealing composite material D for the inner wall of the oil-cooled motor stator.

[0140] In some embodiments, in step SD303, a molding process can be used to composite-mold the annular glass fiber-reinforced resin preform and the inner wall of the oil-cooled motor stator. The pressing pressure is 3 Mpa, and the pressure is maintained until the composite material is cured and formed. The annular glass fiber-reinforced resin preform after being fitted to the inner wall of the motor stator is cured. The curing conditions are a curing time of 60 minutes at a temperature of 90 °C, and then it is raised to 200 °C and cured for 120 minutes, thereby obtaining the inner wall sealing composite material D of the oil-cooled motor stator.

[0141] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be encompassed within the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0142] Finally, it should be noted that the above description has been given for purposes of illustration and description. In addition, the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a composite material for sealing the inner wall of an oil-cooled motor stator, characterized in that: include: Step S100: obtaining a resin matrix and preparing a planar fiber reinforcement or a ring-shaped fiber reinforcement; Step S200: preparing a planar fiber-reinforced resin preform or a ring-shaped fiber-reinforced resin preform, and packaging the planar fiber-reinforced resin preform or the ring-shaped fiber-reinforced resin preform; Step S300: taking a planar fiber reinforced resin preform from the packaged planar fiber reinforced resin preform, cutting and shaping the planar fiber reinforced resin preform to obtain a fiber reinforced resin prefabricated splicing body, spreading the fiber reinforced resin prefabricated splicing body along the inner wall of the oil-cooled motor stator, and pressurizing and bonding the fiber reinforced resin prefabricated splicing body to the inner wall of the oil-cooled motor stator; curing the fiber reinforced resin prefabricated splicing body bonded to the inner wall of the motor stator to obtain a sealing composite material for the inner wall of the oil-cooled motor stator; Alternatively, a ring-shaped fiber reinforced resin preform in a packaged ring-shaped fiber reinforced resin preform is taken, and the ring-shaped fiber reinforced resin preform is spread along the inner wall of the oil-cooled motor stator, and the ring-shaped fiber reinforced resin preform is pressurized and bonded to the inner wall of the oil-cooled motor stator, and the ring-shaped fiber reinforced resin preform bonded to the inner wall of the motor stator is cured to obtain a sealing composite material for the inner wall of the oil-cooled motor stator.

2. The method for preparing a composite material for sealing the inner wall of an oil-cooled motor stator according to claim 1, characterized in that: Step S200 includes: Step S201: sending the planar fiber reinforcement to a padding device containing a resin matrix solution for padding treatment to obtain a prepreg, and sending the prepreg to an oven for precuring to obtain a planar fiber reinforced resin preform; Step S202: affixing a layer of release paper on the upper surface of the planar fiber-reinforced resin preform and a layer of PE film on the lower surface, and packaging them into a roll to obtain a packaged planar fiber-reinforced resin preform; And / or, step S300 includes: Step S301: taking a packaged planar fiber-reinforced resin preform, removing the release paper on the upper surface and the PE film on the lower surface to obtain a planar fiber-reinforced resin preform, cutting and shaping the planar fiber-reinforced resin preform to obtain a fiber-reinforced resin prefabricated splicing body; Step S302: spreading one fiber reinforced resin prefabricated splicing body along the inner wall of the oil-cooled motor stator, splicing one fiber reinforced resin prefabricated splicing body end to end to form one splicing seam, and making the size of one fiber reinforced resin prefabricated splicing body match the size of the inner wall of the oil-cooled motor stator, and utilizing the low viscosity of the resin to bond with the inner wall of the oil-cooled motor stator; or, spreading N fiber reinforced resin prefabricated splicing bodies along the inner wall of the oil-cooled motor stator, each fiber reinforced resin prefabricated splicing body is spliced ​​with adjacent fiber reinforced resin prefabricated splicing bodies to form one splicing seam, and N fiber reinforced resin prefabricated splicing bodies are spliced ​​to form N splicing seams, and making the size of the spliced ​​N fiber reinforced resin prefabricated splicing bodies match the size of the inner wall of the oil-cooled motor stator, and utilizing the low viscosity of the resin to bond with the inner wall of the oil-cooled motor stator, N ≥ 2, N is a positive integer; Step S303: pressurizing and maintaining the inner wall of the oil-cooled motor stator to which the fiber-reinforced resin prefabricated splicing body is bonded, so as to achieve pressurized bonding of the fiber-reinforced resin prefabricated splicing body and the inner wall of the oil-cooled motor stator; curing the fiber-reinforced resin prefabricated splicing body bonded to the inner wall of the motor stator to obtain a sealing composite material for the inner wall of the oil-cooled motor stator.

3. The method for preparing a composite material for sealing the inner wall of an oil-cooled motor stator according to claim 1, characterized in that: Step S200 includes: Step B201: preparing a resin matrix adhesive film, and bonding the ring-shaped fiber reinforcement body to the resin matrix adhesive film to obtain a ring-shaped fiber reinforced resin preform; Step B202: Laminating a layer of PE film on the outer surface of the ring-shaped fiber-reinforced resin preform, and packaging to obtain a packaged ring-shaped fiber-reinforced resin preform; And / or, step S300 includes: Step B301: taking the ring-shaped fiber-reinforced resin preform in the packaged ring-shaped fiber-reinforced resin preform, removing the PE film on the outer surface, to obtain the ring-shaped fiber-reinforced resin preform; Step B302: spreading a ring-shaped fiber-reinforced resin preform along the inner wall of the oil-cooled motor stator, wherein the size of the ring-shaped fiber-reinforced resin preform matches the size of the inner wall of the oil-cooled motor stator, and bonding the ring-shaped fiber-reinforced resin preform to the inner wall of the oil-cooled motor stator by utilizing the low viscosity of the resin matrix; Step B303: pressurizing and maintaining the inner wall of the oil-cooled motor stator to which the ring-shaped fiber-reinforced resin preform is bonded, so as to achieve pressurized bonding of the ring-shaped fiber-reinforced resin preform and the inner wall of the oil-cooled motor stator; curing the ring-shaped fiber-reinforced resin preform bonded to the inner wall of the motor stator to obtain a sealing composite material for the inner wall of the oil-cooled motor stator.

4. A method for preparing a composite material for sealing the inner wall of an oil-cooled motor stator according to claim 2 or 3, characterized in that: In step S100, the planar fiber reinforcement and the ring-shaped fiber reinforcement both include fabrics, the material of the fabric is one or more of aramid fiber, glass fiber, alumina fiber, silicon carbide fiber, ceramic fiber, polyimide fiber, polyparaphenylene benzobisazole fiber, polyparaphenylene terephthalamide fiber, polyphenylsulfoneamide fiber, polyamideimide fiber, polybenzimidazole fiber, and polytetrafluoroethylene fiber, and the material of the resin matrix is ​​one or more of epoxy resin, phenolic resin, unsaturated polyester resin, polyimide resin, urea-formaldehyde resin, and amino resin;.

5. The method for preparing a composite material for sealing the inner wall of an oil-cooled motor stator according to claim 4, characterized in that: In step S100, preparing a planar fiber reinforcement or a ring-shaped fiber reinforcement includes: the fabric is subjected to a surface modification process to form a fiber reinforcement, and the surface modification process includes one or more of a plasma process, an ultrasonic process, a laser process, an acid-base process, a chemical etching process, a coupling agent process and a surface coating modification process; the thickness of the fiber reinforcement is 0.05-3mm, and the diameter of the fiber is 5-15μm.

6. The method for preparing a composite material for sealing the inner wall of an oil-cooled motor stator according to claim 5, characterized in that: In step S201, during the padding treatment, the temperature of the resin matrix solution is 20-100°C; the immersion time of the fiber reinforcement in the resin matrix solution is 1-10 min; the padding speed of the padding treatment is 5-15 m / min, the padding pressure is 1-2000 kPa, the resin matrix content in the prepreg is 20%-80%, the precuring time is 1-30 min, and the precuring temperature is 50-200°C.

7. A method for preparing a composite material for sealing the inner wall of an oil-cooled motor stator according to claim 2 or 3, characterized in that: In step S300, the pressurization method includes mechanical pressurization, the pressurization pressure of the mechanical pressurization is 1-10Mpa, and the mechanical pressurization method is compression molding; or, the pressurization method includes gas pressurization, the pressurization pressure of the gas pressurization is 1-10Mpa, and the gas pressurization method includes one or more of vacuum bag molding, air pressure chamber molding, and autoclave molding.

8. The method for preparing a composite material for sealing the inner wall of an oil-cooled motor stator according to claim 7, characterized in that: In step S300, the curing process adopts a gradient temperature rise curing molding process, the curing temperature is 20-200°C, and the curing time is 30-200min.

9. A composite material for sealing the inner wall of an oil-cooled motor stator, obtained by using the method for preparing a composite material for sealing the inner wall of an oil-cooled motor stator according to any one of claims 1 to 8. 10 . The oil-cooled motor stator inner wall sealing composite material according to claim 9 , wherein the oil-cooled motor stator inner wall sealing composite material is formed on the inner wall of the oil-cooled motor stator.

Images