Magnetic slot wedge for new energy automobile motor and preparation process of magnetic slot wedge

Abstract

The invention discloses a magnetic slot wedge for a new energy automobile motor and a preparation process of the magnetic slot wedge. The magnetic slot wedge comprises a magnetic conductive core body and an insulating layer wrapping the magnetic conductive core body, the magnetic conductive core body is made of a high-magnetic-conductivity silicon steel sheet, and the insulating layer is made of a fiber / thermoplastic resin matrix composite material. The magnetic slot wedge is manufactured through a compression molding process. According to the magnetic slot wedge for the new energy automobile motor and the preparation technology of the magnetic slot wedge, the silicon steel sheet is adopted as the magnetic conductive core body, the fiber / thermoplastic resin matrix composite material is wrapped outside the magnetic conductive core body to serve as the insulating layer, and the magnetic slot wedge is prepared in a mold pressing mode. Therefore, the magnetic leakage phenomenon is reduced, the electromagnetic efficiency and the power density of the motor are improved, the endurance mileage of the automobile is improved, the cogging torque fluctuation of the motor can be effectively reduced, the motor runs more stably and quietly, and the user experience of the whole automobile can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of motors, and particularly relates to a magnetic slot wedge for a new energy vehicle motor and a preparation process thereof. Background Art

[0002] The energy issue is an important issue related to the sustainable development of mankind. With the development of the economy and social progress, the awareness of energy conservation has gradually taken root in people's hearts. With the global emphasis on sustainable development, new energy vehicles (such as electric vehicles and hybrid vehicles) have developed rapidly as an important means to reduce carbon emissions and address climate change. In the core system of new energy vehicles, the motor is a key component for driving power, and its performance directly determines the power output, energy efficiency, and cruising range of the whole vehicle. Therefore, improving the efficiency and power density of motors is an important topic in the development of current motor technology.

[0003] In traditional motors, the stator windings are fixed in the slots of the stator core by slot wedges. As an important component between the stator and windings of the motor, the slot wedge mainly plays a role in fixing the windings, preventing the windings from loosening or detaching, and at the same time has a certain insulation effect.

[0004] However, traditional slot wedges are usually made of non-magnetic materials, such as glass fiber, epoxy resin, or other insulating materials. The magnetic permeability of these materials is extremely low, and they cannot effectively guide or control the magnetic flux inside the motor, which may lead to magnetic leakage between the stator teeth and slots. Magnetic leakage will directly reduce the electromagnetic efficiency of the motor, cause insufficient power output of the motor, and increase energy loss. This will shorten the cruising range of new energy vehicles, which is particularly disadvantageous to the development of new energy vehicles.

[0005] To solve the above problems, the present invention provides a magnetic slot wedge. Its core concept is to introduce a soft magnetic material with high magnetic permeability into the slot wedge to replace the traditional non-magnetic slot wedge. This slot wedge uses silicon steel sheets as the magnetic conduction core, and a fiber / thermoplastic resin-based composite material is wrapped around its outside as an insulating layer, and is prepared by die pressing. During the working process of this magnetic slot wedge, it can guide part of the magnetic leakage back into the magnetic circuit, thereby reducing the magnetic leakage phenomenon, improving the electromagnetic efficiency and power density of the motor, and thus increasing the cruising range of the vehicle. In addition, this magnetic slot wedge can effectively reduce the cogging torque fluctuation of the motor, make the motor operate more smoothly and quietly, and can improve the user experience of the whole vehicle. Summary of the Invention

[0006] Object of the Invention: To overcome the above deficiencies, the object of the present invention is to provide a magnetic slot wedge for a new energy vehicle motor and a preparation process thereof, which is reasonably designed, replaces the traditional non-magnetic slot wedge, thereby improving the electromagnetic efficiency of the motor, reducing magnetic flux leakage, optimizing the motor performance, and having a wide application prospect.

[0007] The object of the present invention is achieved by the following technical solutions: A magnetic slot wedge for a new energy vehicle motor, the magnetic slot wedge includes a magnetic core body and an insulating layer wrapped outside the magnetic core body; the magnetic core body is made of high magnetic permeability silicon steel sheet, and the insulating layer is made of fiber / thermoplastic resin-based composite material.

[0008] Traditional slot wedges mostly use non-magnetic materials, and there is a magnetic leakage problem during the operation of the motor, resulting in an increase in energy loss. The present invention uses a high magnetic permeability silicon steel sheet as the magnetic core body, which can effectively reduce magnetic leakage. The high magnetic permeability of the silicon steel sheet makes the magnetic flux easier to pass through the slot wedge, guiding part of the magnetic flux back into the magnetic circuit, reducing the magnetic leakage between the stator teeth and the slots, thereby reducing the energy loss of the motor and improving the efficiency of the motor.

[0009] Compared with ferrite, the silicon steel sheet shows better toughness and can withstand higher pressure during the molding process, making the external composite material bond more closely. In actual use of the product, the fatigue resistance and seismic performance of the silicon steel sheet are significantly better than those of ferrite. In addition, the relatively high processing temperature of the thermoplastic composite material poses a risk of demagnetization for ferrite.

[0010] The external fiber / thermoplastic resin-based composite insulating layer endows the magnetic slot wedge with good mechanical properties and electrical insulation. Fiber materials (such as carbon fiber, glass fiber, aramid fiber, etc.) have the characteristics of high strength and high modulus, which can enhance the mechanical strength of the slot wedge, making it able to withstand various forces during the operation of the motor without being easily damaged. Thermoplastic resins (such as polyphenylene sulfide (PPS), nylon 66 (PA66), polypropylene (PP), etc.) provide good insulation performance to ensure the electrical safety of the motor.

[0011] Further, for the above-mentioned magnetic slot wedge for a new energy vehicle motor, a positioning groove is provided on the working surface of the magnetic slot wedge, forming a mechanical-magnetic double coupling with the stator.

[0012] During the operation of the motor, due to factors such as vibration, the stator winding may loosen or even pop out. The design of the positioning groove can effectively fix the motor stator winding, prevent it from shifting during operation, and ensure the stability and reliability of the motor.

[0013] The magnetic coupling effect between the magnetic slot wedge and the stator can guide part of the magnetic flux back into the magnetic circuit, reducing the magnetic leakage between the stator teeth and the slots. The design of the positioning groove further enhances this magnetic coupling effect, making the magnetic flux more concentratedly pass through the magnetic circuit and improving the magnetic performance of the motor.

[0014] Furthermore, for the magnetic slot wedge used in the new energy vehicle motor mentioned above, the relative magnetic permeability of the high magnetic permeability silicon steel sheet is 7000 - 10000; in the fiber / thermoplastic resin matrix composite material, the fiber includes at least one of carbon fiber, glass fiber, and aramid fiber, and the resin includes at least one of PPS, PA66, PP, and modified products of the above resins; the mass ratio of fiber to resin in the fiber / thermoplastic resin matrix composite material is (50 - 65):(35 - 50).

[0015] The high magnetic permeability (relative magnetic permeability of 7000 - 10000) makes the magnetic flux easier to pass through the slot wedge, improves the magnetic circuit performance of the motor, and increases the efficiency and power factor of the motor. The diverse selection of fibers and resins in the fiber / thermoplastic resin matrix composite material enables the magnetic slot wedge to be customized according to different application scenarios and performance requirements.

[0016] Furthermore, for the magnetic slot wedge used in the new energy vehicle motor mentioned above, the magnetic slot wedge is manufactured by a compression molding process.

[0017] The compression molding process can ensure high precision of the dimensions of the magnetic slot wedge product. During the compression molding process, through precise control of process parameters such as temperature and pressure, the fiber / thermoplastic resin matrix composite material can be tightly combined with the silicon steel sheet core to form an integral structure, thereby endowing the magnetic slot wedge with good mechanical properties and stable electromagnetic properties.

[0018] Furthermore, for the magnetic slot wedge used in the new energy vehicle motor mentioned above, the mold used in the compression molding process includes a bottom plate, an upper cover, an inner core, and positioning screws; the bottom plate and the upper cover form a mold cavity, the inner core is arranged on the bottom plate, resin particle grooves and corresponding resin inlet holes are respectively arranged at both ends of the upper cover, resin flow guide grooves are arranged on both the bottom plate and the upper cover, and the positioning screws are used to lock the bottom plate and the upper cover.

[0019] The bottom plate provides stable support for the mold, the upper cover and the bottom plate cooperate to form a mold cavity, the inner core is used to position the preform to prevent it from slipping during the compression molding process. The positioning screws are used to lock the upper and lower molds (i.e., the upper cover and the bottom plate) to ensure the sealing performance of the mold during the compression molding process, and the resin particle grooves are used to store resin particles.

[0020] Traditional slot wedges often need to be coated with resin on the surface after compression molding production to ensure the appearance and geometric accuracy of the slot wedge. In the present invention, 2 resin particle grooves are designed on the upper cover of the mold. During the preheating process of the mold, the resin particles enter the mold cavity from the resin particle grooves at both ends through the resin inlet holes, and then are evenly distributed on the outer layer of the prepreg through the resin flow guide grooves to form a resin layer. This design can adapt to the characteristics of the silicon steel sheet and the prepreg tape, and ensure the precise geometric shape and surface smoothness of the slot wedge.

[0021] The present invention also relates to the application of the magnetic slot wedge. The magnetic slot wedge is not only applicable to the motors of new energy vehicles, but also can be applied to industrial motors, aerospace motors and other fields. By adjusting the material of the silicon steel sheet and the formula of the prepreg tape, the requirements for the motor performance in different fields can be met.

[0022] The present invention also relates to the preparation process of the magnetic slot wedge for the motor of new energy vehicle, which comprises the following steps: S1: Select a silicon steel sheet, and wind a thermoplastic resin prepreg tape outside the silicon steel sheet to prepare a preform; S2: Place the preform into the cavity of the mold, use the inner core for positioning, close the mold and lock it with positioning screws, and add resin particles into the resin particle groove of the mold; S3: Place the mold between the hot press pallets for preheating; S4: After the preheating is completed, apply pressure to the mold and hold the pressure to make the thermoplastic resin prepreg tape and the resin particles closely combine with the silicon steel sheet; S5: Hold the pressure and cool down, open the mold after the temperature drops, and take out the magnetic slot wedge.

[0023] Through the above preparation process, the thermoplastic resin prepreg tape can evenly wrap on the silicon steel sheet core to form an integral structure, realizing the tight combination of the magnetic material and the insulating layer. During the preheating and pressurizing processes, the resin particles melt and fully infiltrate the silicon steel sheet together with the resin in the prepreg tape, forming a firm combination between the insulating layer and the core, ensuring that the magnetic slot wedge has reliable insulating performance and mechanical performance during the operation of the motor.

[0024] Further, for the preparation process of the magnetic slot wedge for the motor of new energy vehicle, in the above S1, the thickness of the silicon steel sheet is 0.4 - 0.65 mm, the thermoplastic resin prepreg tape adopts symmetric laying, and the number of laying layers is 1 - 5 layers; in the above S3, the preheating temperature is 230 - 330 °C, and the preheating time is 0.5 - 1 h; in the above S4, the applied pressure is 3 - 5 MPa, and the pressure holding time is 0 - 1 h; in the above S5, the pressure holding and cooling time is 0 - 1 h.

[0025] The reasonable selection and control of parameters such as the thickness of the silicon steel sheet, the laying layer of the prepreg tape, the preheating temperature, the preheating time, the pressure, the pressure holding time and the pressure holding and cooling time can optimize the performance of the magnetic slot wedge.

[0026] Further, in the preparation process of the magnetic slot wedge for the new energy vehicle motor described above, in S1, the thickness of the silicon steel sheet is 0.5 mm, the thermoplastic resin prepreg tape is symmetrically laminated at ±45°, and 2 layers are laminated; in S3, the preheating temperature of PPS is 330 °C, the preheating temperature of PA66 is 280 °C, the preheating temperature of PP is 230 °C, and the preheating time is 0.5 h; in S4, the applied pressure is 3 MPa, and the pressure holding time is 0.5 h; in S5, the pressure holding and cooling time is 0.5 h.

[0027] Further, in the preparation process of the magnetic slot wedge for the new energy vehicle motor described above, in S5, after the magnetic slot wedge is taken out, post-treatment is carried out. The post-treatment includes deburring treatment and surface grinding and polishing. Grinding can eliminate the flash on the parting surface.

[0028] Further, in the preparation process of the magnetic slot wedge for the new energy vehicle motor described above, in S1, the thermoplastic resin prepreg tape is a glass fiber-PPS prepreg tape or a glass fiber woven fabric-PA66 prepreg tape; in the glass fiber-PPS prepreg tape, the mass ratio of glass fiber to PPS is 3:2; in the glass fiber woven fabric-PA66 prepreg tape, the mass ratio of the glass fiber woven fabric to PA66 is 3:2, and the areal density of the glass fiber woven fabric is 160~390 g / m 2 。

[0029] Preferably, the areal density of the glass fiber woven fabric is 300 g / m 2 。

[0030] Compared with the prior art, the present invention has the following beneficial effects: (1) The magnetic slot wedge for the new energy vehicle motor disclosed by the present invention uses a silicon steel sheet as the slot wedge core body. Through optimization design, the slot wedge has a high magnetic permeability, reduces magnetic leakage, and reduces the energy loss of the motor; (2) The magnetic slot wedge for the new energy vehicle motor disclosed by the present invention uses a fiber / thermoplastic resin matrix composite material as the shell of the slot wedge, so that the finished product has good mechanical properties and electrical insulation. The thermoplastic resin prepreg tape is evenly wrapped on the silicon steel sheet through a molding process to form an integral structure, realizing the tight combination of the magnetic material and the insulating layer, and ensuring reliable insulation performance during the operation of the motor; (3) The magnetic slot wedge for the new energy vehicle motor disclosed by the present invention is designed with two resin particle grooves on the mold cover. During the preheating process of the mold, the resin enters the mold cavity from the inflow holes at both ends, and a resin layer is formed on the outer layer of the prepreg, ensuring the precise geometric shape and surface smoothness of the slot wedge to meet the high matching requirements of the motor. At the same time, the integrated molding process shortens the process flow; (4)The preparation process of the magnetic slot wedge for the new energy vehicle motor disclosed by the present invention is reasonably designed. During the preheating and pressurization processes, the resin particles melt and fully infiltrate the silicon steel sheet together with the resin in the prepreg tape, forming a firm bond between the insulating layer and the magnetic core body, ensuring that the magnetic slot wedge has reliable insulation performance and mechanical properties during the operation of the motor; the preparation process precisely controls the parameters of each step, such as preheating temperature, pressure, pressure holding time, etc., and can ensure the quality and consistency of the magnetic slot wedge products. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic structural diagram of the magnetic slot wedge for the new energy vehicle motor described in the present invention; Figure 2 is a schematic structural diagram of the mold used in the compression molding process of the magnetic slot wedge for the new energy vehicle motor described in the present invention; Figure 3 is a top view of the bottom plate of the mold used in the compression molding process of the magnetic slot wedge for the new energy vehicle motor described in the present invention; Figure 4 is a bottom view of the upper cover of the mold used in the compression molding process of the magnetic slot wedge for the new energy vehicle motor described in the present invention; In the figure: magnetic slot wedge 1, positioning groove 11; mold 2, bottom plate 21, resin diversion groove 211, upper cover 22, resin particle groove 221, resin inlet hole 222, inner core 23, positioning screw 24. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] Next, Examples 1 and 2, Comparative Example 1, and Comparative Example 2 will be combined with Figure 1 , 2 , Figures 3 and 4 and specific experimental data to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention. As Figure 1 shown, the magnetic slot wedge 1 for the new energy vehicle motor described in the present invention includes a magnetic core body and an insulating layer wrapped around the outside of the magnetic core body. A plurality of positioning grooves 11 are provided on the working surface of the magnetic slot wedge 1, which can form a mechanical-magnetic double coupling with the stator.

[0033] Among them, the magnetic core body is made of high magnetic permeability silicon steel sheet.

[0034] Further, the relative magnetic permeability of the high magnetic permeability silicon steel sheet is 7000 - 10000.

[0035] Among them, the insulating layer is made of a fiber / thermoplastic resin-based composite material.

[0036] Furthermore, in the fiber / thermoplastic resin-based composite material, the fiber includes at least one of carbon fiber, glass fiber, and aramid fiber, the resin includes at least one of PPS, PA66, PP, and modified products of the above resins, and the mass ratio of fiber to resin in the fiber / thermoplastic resin-based composite material is (50~65):(35~50).

[0037] As Figure 2 、 3 、shown in Figure 4, the magnetic slot wedge for a new energy vehicle motor of the present invention is manufactured by a compression molding process. The mold 2 used in the compression molding process includes a bottom plate 21, an upper cover 22, two inner cores 23, and four positioning screws 24. A mold cavity is formed between the bottom plate 21 and the upper cover 22. Two inner cores 23 are provided on the bottom plate 21 for positioning. One resin particle groove 221 and corresponding resin inlet holes 222 are respectively provided at both ends of the upper cover 22. Resin guide grooves 211 surrounding the mold cavity are provided on the bottom plate 21 and the upper cover 22. The four positioning screws 24 are used to lock the bottom plate 21 and the upper cover 22.

[0038] Examples 1, 2, Comparative Example 1, and Comparative Example 2 provide a magnetic slot wedge and a preparation process.

[0039] Example 1 The preparation of the magnetic slot wedge in Example 1 includes the following steps: S1: Select a silicon steel sheet with a thickness of 0.5 mm (Baoshan Iron & Steel Co., Ltd., product grade B35A210) as the magnetic core, and wind a thermoplastic resin prepreg tape (±45° symmetric ply, 2 plies, taking into account the tensile strength of the finished magnetic slot wedge and the wrapping of the magnetic core) as the insulating layer; among them, the thermoplastic resin prepreg tape is made of glass fiber-PPS (self-made, glass fiber mass content 60%, PPS mass content 40%, tensile strength 840 MPa) to prepare a preform; S2: As Figure 2 、 3 、shown in Figure 4, place the preform into the mold cavity of the mold 2, use the inner core 23 for positioning, close the mold 2 and use the positioning screws 24 to lock the bottom plate 21 and the upper cover 22. Add resin particles into the resin particle groove 221 of the upper cover 22. The resin particles enter the mold cavity through the resin inlet holes 222 at both ends of the upper cover 22, and then are evenly distributed on the outer layer of the preform through the resin guide grooves 211; S3: Place the mold 2 between the hot pressing platform pallets, preheat for 0.5 h, and the preheating temperature is 330°C; S4: After the preheating is completed, apply a pressure of 3 MPa to the mold 2 for a holding pressure time of 0.5 h to tightly bond the thermoplastic resin prepreg tape of the preform with the magnetic core; S5: Hold the pressure and cool for 0.5 h to ensure the stability of the dimensions of the magnetic slot wedge. After cooling, open the mold 2, take out the magnetic slot wedge 1 and perform post-treatment. The post-treatment includes deburring and surface grinding and polishing. Grinding can eliminate the flash on the parting surface, and the magnetic slot wedge of Example 1 is obtained.

[0040] Example 2 The preparation of the magnetic slot wedge of Example 2 includes the following steps: S1: Select a silicon steel sheet with a thickness of 0.5 mm (Baoshan Iron & Steel Co., Ltd., product grade B35A210) as the magnetic core, and wind a thermoplastic resin prepreg tape (±45° symmetric ply, 2 plies) as the insulating layer on the outside; among them, the thermoplastic resin prepreg tape is made of glass fiber woven fabric - PA66 (self-made, the mass content of glass fiber woven fabric is 60%, the mass content of PA66 is 40%, and the surface density of the fiber cloth is 300 g / m 2 , with a tensile strength of 388 MPa) to prepare a preform; S2: As shown in Figure 2 、 3 、4, place the preform into the cavity of the mold 2, use the insert 23 for positioning, close the mold 2 and lock the bottom plate 21 and the upper cover 22 with the positioning screw 24. Add resin particles into the resin particle groove 221 of the upper cover 22. The resin particles enter the cavity from the resin particle grooves 221 at both ends of the upper cover 22 through the resin inflow holes 222, and then are evenly distributed on the outer layer of the preform through the resin diversion grooves 211; S3: Place the mold 2 between the hot press pallets and preheat for 0.5 h at a preheating temperature of 280 °C (the preheating process temperature of PA66 is lower, which can reduce the risk of demagnetization of the silicon steel sheet); S4: After the preheating is completed, apply a pressure of 3 MPa to the mold 2 for a holding pressure time of 0.5 h to tightly bond the thermoplastic resin prepreg tape of the preform with the magnetic core; S5: Hold the pressure and cool for 0.5 h to ensure the stability of the dimensions of the magnetic slot wedge 1. After cooling, open the mold 2, take out the magnetic slot wedge 1 and perform post-treatment. The post-treatment includes deburring and surface grinding and polishing. Grinding can eliminate the flash on the parting surface, and the magnetic slot wedge of Example 2 is obtained.

[0041] Comparative Example 1 The preparation of the magnetic slot wedge of Comparative Example 1 includes the following steps: S1: Select a silicon steel sheet with a thickness of 0.5 mm (Baoshan Iron & Steel Co., Ltd., product grade B35A210) as the magnetic core, and wind a thermoplastic resin prepreg tape (symmetrically laid at ±45°, 2 layers of laying) on the outside as the insulating layer; among them, the thermoplastic resin prepreg tape is made of glass fiber / polyether ether ketone (PEEK) (self-made, the mass content of glass fiber is 60%, the mass content of PEEK is 40%, and the tensile strength is 920 MPa) to prepare a preform; S2: As shown in Figure 2 , 3 , 4, place the preform into the cavity of mold 2, use the insert 23 for positioning, close the mold 2 and use the positioning screw 24 to lock the bottom plate 21 and the upper cover 22. Add resin particles into the resin particle groove 221 of the upper cover 22. The resin particles enter the cavity through the resin inflow holes 222 at both ends of the upper cover 22, and then are evenly distributed on the outer layer of the preform through the resin diversion groove 211; S3: Place mold 2 between the hot pressing platform pallets, preheat for 0.5 h, and the preheating temperature is above 380 °C (the preheating process temperature of PEEK is above 380 °C, which has a higher energy cost; the preheating process temperature of PEEK is close to the demagnetization temperature of the silicon steel sheet. When the silicon steel sheet is heated to this temperature, the internal magnetic exchange effect will weaken, ultimately resulting in poor magnetic permeability of the magnetic slot wedge); S4: After the preheating is completed, apply a pressure of 3 MPa to mold 2 and keep the pressure for 0.5 h to make the thermoplastic resin prepreg tape of the preform tightly combined with the magnetic core; S5: Keep the pressure and cool for 0.5 h to ensure the stable size of the magnetic slot wedge 1. After cooling, open mold 2, take out the magnetic slot wedge 1 and perform post-treatment. The post-treatment includes deburring treatment and surface grinding and polishing. Grinding can eliminate the flash on the parting surface to obtain the magnetic slot wedge of Comparative Example 1.

[0042] Comparative Example 2 For the magnetic slot wedge of Comparative Example 2, select a ferrite with a thickness of 0.5 mm (Anhui Xinyue Magnet Products Co., Ltd., product grade Y30) as the magnetic core, and the other preparation steps are the same as those in Example 1.

[0043] Effect verification Perform magnetic permeability tests on the magnetic slot wedges prepared in Example 1, Example 2, Comparative Example 1, and Comparative Example 2. The magnetic permeability test uses the induction coil method, and the measurement results are shown in Table 1.

[0044] Table 1 It can be obtained from Table 1 that: In both Example 1 and Example 2, silicon steel sheets with a thickness of 0.5 mm and grade B35A210 are selected as the magnetic core. The silicon steel sheets have good toughness and can withstand high pressure during molding, enabling the external fiber / thermoplastic resin matrix composite to be tightly combined. Their fatigue resistance and seismic resistance are superior to those of ferrite, and the processing temperature of the fiber / thermoplastic resin matrix composite has relatively little impact on its demagnetization.

[0045] The difference is that in Example 1, a glass fiber-PPS prepreg tape is used, and in Example 2, a glass fiber woven fabric-PA66 prepreg tape is used. There are differences in their tensile strength properties. The preheating temperature of Example 1 is 330 °C, and the preheating temperature of Example 2 is 280 °C. The lower preheating temperature can reduce the demagnetization risk of the silicon steel sheet and protect the magnetic properties of the silicon steel sheet better while ensuring the bonding effect.

[0046] In Example 1 and Example 2, the relative permeability can reach over 1300 at low frequencies. The relative permeability of Example 1 at 100 Hz is 1335.09, and the relative permeability of Example 2 at 100 Hz is 1313.55, showing good magnetic conduction effects, indicating that the combination of their materials and processes can effectively ensure the magnetic permeability. In Comparative Example 1, silicon steel sheets with a thickness of 0.5 mm and grade B35A210 are also used as the magnetic core, but the thermoplastic resin prepreg tape selected is glass fiber / polyether ether ketone. Although it has high tensile strength, the preheating process temperature is unfavorable, and the preheating temperature is above 380 °C. This temperature not only has a high energy cost but also is close to the demagnetization temperature of the silicon steel sheet, easily causing the magnetic permeability of the magnetic slot wedge to deteriorate. The relative permeability at each frequency is much lower than that of Example 1 and Example 2. For example, the relative permeability at 100 Hz is only 336.59, indicating that its preheating temperature has a greater impact on the magnetic properties of the silicon steel sheet, resulting in a deterioration of the magnetic permeability.

[0047] In Comparative Example 2, ferrite is selected as the magnetic slot wedge material, which has obvious disadvantages in terms of toughness, molding adaptability, and magnetic permeability uniformity. Specifically, sheet ferrite is brittle and easily damaged by external pressure and vibration, requiring low molding pressure, resulting in poor wrapping of the composite material around the core in the finished product, unstable dimensions, and low yield. While powder ferrite preforms need to be fixed with glue spraying and it is difficult to control their uniform distribution in the finished product, resulting in poor magnetic permeability of the finished product.

[0048] Therefore, the magnetic permeability of Comparative Example 2 is the worst, and the relative permeability at 100 Hz is 78.64, which is related to its material characteristics (such as being fragile and unevenly distributed), affecting the overall magnetic conduction performance.

[0049] In summary, by adopting the technical solution of the present invention, the technical problems of new energy motors on the current market are solved. By introducing silicon steel sheets with high magnetic permeability into the slot wedges to replace the traditional non-magnetic slot wedges. During the operation of the magnetic slot wedges, part of the leakage magnetic flux can be guided back into the magnetic circuit, thereby reducing the leakage magnetic flux phenomenon, improving the electromagnetic efficiency and power density of the motor, and thus increasing the driving range of the vehicle. In addition, the magnetic slot wedges can effectively reduce the cogging torque fluctuation of the motor, making the motor operate more smoothly and quietly, and improving the user experience of the whole vehicle.

[0050] It should be noted that the fibers used in the fiber / thermoplastic resin matrix composite material of the present invention include but are not limited to carbon fibers, glass fibers, aramid fibers, and the thermoplastic resins used include but are not limited to PPS, PA66, PP, and modified products of the above resins.

[0051] It should be noted that the magnetic slot wedge technology of the present invention is not only applicable to new energy vehicle motors, but also can be applied to industrial motors, aerospace motors and other fields. By adjusting the material of the silicon steel sheet and the formula of the prepreg, the requirements for motor performance in different fields can be met.

[0052] There are many specific application ways of the present invention, and the above description is only the preferred embodiment of the present invention. It should be pointed out that the above embodiments are only used to illustrate the present invention and do not limit the protection scope of the present invention. For those of ordinary skill in the art of this technology, several improvements can be made without departing from the principle of the present invention, and these improvements should also be regarded as the protection scope of the present invention.

Claims

1. A magnetic slot wedge for a motor of a new energy vehicle, characterized in that The magnetic slot wedge (1) includes a magnetic core and an insulating layer wrapped around the magnetic core; the magnetic core is made of high-permeability silicon steel sheets, and the insulating layer is made of a fiber / thermoplastic resin-based composite material.

2. The magnetic slot wedge for a new energy vehicle motor according to claim 1, wherein The working surface of the magnetic slot wedge (1) is provided with a positioning groove (11), forming a mechanical-magnetic double coupling with the stator.

3. The magnetic slot wedge for the motor of a new energy vehicle according to claim 1, characterized in that, The relative permeability of the high-permeability silicon steel sheets is 7,000 to 10,000; in the fiber / thermoplastic resin-based composite material, the fiber includes at least one of carbon fiber, glass fiber, and aramid fiber, and the resin includes at least one of PPS, PA66, PP, and modified products of the above resins; the mass ratio of the fiber to the resin in the fiber / thermoplastic resin-based composite material is (50 - 65):(35 - 50).

4. The magnetic slot wedge for the motor of a new energy vehicle according to claim 1, characterized in that The magnetic slot wedge (1) is manufactured by a compression molding process.

5. The magnetic slot wedge for a new energy vehicle motor according to claim 4, wherein The mold (2) used in the compression molding process includes a bottom plate (21), an upper cover (22), an inner core (23), and positioning screws (24); the bottom plate (21) and the upper cover (22) form a mold cavity, the bottom plate (21) is provided with an inner core (23), resin particle grooves (221) and corresponding resin inlet holes (222) are respectively provided at both ends of the upper cover (22), resin diversion grooves (211) are provided on the bottom plate (21) and the upper cover (22), and the positioning screws (24) are used to lock the bottom plate (21) and the upper cover (22).

6. The preparation process of the magnetic slot wedge for the motor of a new energy vehicle according to any one of claims 1 to 5, characterized in that, It includes the following steps: S1: Select silicon steel sheets, and wind thermoplastic resin prepreg tapes outside the silicon steel sheets to prepare a preform. S2: Place the preform into the mold cavity of the mold (2), use the inner core (23) for positioning, close the mold (2) and lock it with the positioning screws (24), and add resin particles into the resin particle grooves (221) of the mold (2). S3: Place the mold (2) between the hot press pallets for preheating. S4: After the preheating is completed, apply pressure to the mold (2), hold the pressure, so that the thermoplastic resin prepreg tapes and the resin particles are tightly combined with the silicon steel sheets. S5: Hold the pressure and cool, open the mold (2) after the temperature drops, and take out the magnetic slot wedge.

7. The preparation process of the magnetic slot wedge for the motor of the new energy vehicle according to claim 6, characterized in that, In S1, the thickness of the silicon steel sheets is 0.4 - 0.65 mm, the thermoplastic resin prepreg tapes adopt a symmetric layup, and the number of layups is 1 - 5 layers; in S3, the preheating temperature is 230 - 330 °C, and the preheating time is 0.5 - 1 h; in S4, the applied pressure is 3 - 5 MPa, and the pressure holding time is 0 - 1 h; in S5, the pressure holding and cooling time is 0 - 1 h.

8. The preparation process of the magnetic slot wedge for the motor of a new energy vehicle according to claim 7, characterized in that In S1, the thickness of the silicon steel sheets is 0.5 mm, the thermoplastic resin prepreg tapes adopt a ±45° symmetric layup, and the number of layups is 2 layers; in S3, the preheating temperature of PPS is 330 °C, the preheating temperature of PA66 is 280 °C, the preheating temperature of PP is 230 °C, and the preheating time is 0.5 h; in S4, the applied pressure is 3 MPa, and the pressure holding time is 0.5 h; in S5, the pressure holding and cooling time is 0.5 h.

9. The preparation process of the magnetic slot wedge for the motor of new energy vehicle according to claim 6, characterized in that, In S5, after taking out the magnetic slot wedge, perform deburring treatment and surface grinding and polishing.

10. The preparation process of the magnetic slot wedge for the motor of the new energy vehicle according to claim 6, characterized in that, In S1, the thermoplastic resin prepreg tape is a glass fiber-PPS prepreg tape or a glass fiber woven fabric-PA66 prepreg tape; in the glass fiber-PPS prepreg tape, the mass ratio of glass fiber to PPS is 3:2; in the glass fiber woven fabric-PA66 prepreg tape, the mass ratio of the glass fiber woven fabric to PA66 is 3:2, and the areal density of the glass fiber woven fabric is 160~390 g / m 2 .

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