Motor stator and preparation method thereof, motor, electric drive system and automobile

Abstract

The present application provides a motor stator and its preparation method, a motor, an electric drive system and a car, which belong to the field of electric drive system manufacturing technology. The material of the motor stator includes an amorphous soft magnetic alloy, and the molecular formula of the amorphous soft magnetic alloy is: Fe a Si b B c Cu d Co e M f , wherein M is selected from at least one of Zr, Hf and Nb, 70≤a≤85, 0.65≤b≤8.5, 0.5≤c≤6, 0.7≤d≤2.5, 0.25≤e≤5, 2.5≤f≤8, and satisfies a+b+c+d+e+f=100. The motor assembled by the motor stator can have both higher power and efficiency, so that the electric vehicle has a longer driving range, thereby meeting the user's demand for a high-performance electric drive system.

Description

Technical Field

[0001] The present application relates to the technical field of electric drive system manufacturing, and more specifically, to a motor stator and a manufacturing method thereof, a motor, an electric drive system, and a vehicle. Background Art

[0002] For pure electric vehicles, the vehicle is mainly driven by the electric drive system. With the development of society, users have increasingly higher performance requirements for the electric drive system. Specifically, users have begun to pursue electric drive systems with higher power and efficiency to enable electric vehicles to have longer driving range. However, the development of the material systems commonly used to manufacture motors (such as silicon steel) has basically reached its limit in terms of power and efficiency, and it is difficult to achieve further improvement. Therefore, there is an urgent need to introduce new material systems into the field of automotive drive technology to prepare motors with higher power and efficiency, thereby meeting users' demand for high-performance motor systems. Summary of the Invention

[0003] The purpose of this application is to provide a motor stator and its preparation method, a motor, an electric drive system and a car. The motor assembled by the motor stator can have both higher power and efficiency, so that the electric car has a longer range, thereby meeting the user's demand for high-performance electric drive systems.

[0004] The embodiment of the present application is implemented as follows:

[0005] In a first aspect, the present invention provides a motor stator, wherein the material of the motor stator includes an amorphous soft magnetic alloy, and the molecular formula of the amorphous soft magnetic alloy is: Fe a Si b B c Cu d Co e M f , wherein M is selected from at least one of Zr, Hf and Nb, 70≤a≤85, 0.65≤b≤8.5, 0.5≤c≤6, 0.7≤d≤2.5, 0.25≤e≤5, 2.5≤f≤8, and satisfies a+b+c+d+e+f=100.

[0006] In the above technical solution, the amorphous soft magnetic alloy with a specific molecular formula has the characteristics of high saturation magnetic induction intensity, low magnetic loss and good plasticity. This material is introduced into the field of electric drive systems and used as the main material for manufacturing motor stators, so that the corresponding motor has higher power and efficiency, thereby making electric vehicles have longer endurance, to meet users' needs for high-performance electric drive systems.

[0007] In a second aspect, an embodiment of the present application provides a method for preparing a motor stator as provided in the embodiment of the first aspect, comprising the following steps:

[0008] A strip material made of an amorphous soft magnetic alloy and having a thickness of 0.02 to 0.03 mm is provided; the strip material is annealed at a temperature not higher than 370° C. to obtain a sheet precursor; a plurality of sheet precursors are subjected to a first lamination and composite process to connect the plurality of sheet precursors into a whole to obtain a sheet; the sheet is blanked to obtain a motor stator precursor; the plurality of motor stator precursors are subjected to a second lamination and composite process to connect the plurality of motor stator precursors into a whole to obtain a motor stator.

[0009] In the above technical solution, according to the above method, a thin sheet of amorphous soft magnetic alloy material with advantages such as high saturation magnetic induction intensity, low magnetic loss and good plasticity can be prepared into a motor stator, so that the corresponding motor has higher power and efficiency; wherein, when the strip is of a specific material and the thickness is within a specific range, the annealing temperature is set within a range not higher than 370°C, which can make the strip have relatively excellent toughness and strength after annealing, so that the strip has better processing performance (that is, improving the problem of slagging or even breakage of the strip during subsequent processing), thereby making the motor stator prepared from the strip of this specific material and specific thickness have higher power and efficiency.

[0010] In some optional embodiments, in the annealing step, the treatment temperature is 180-320° C., and the treatment time is 60-200 s.

[0011] In the above technical solution, the treatment temperature and time during the annealing process are limited to specific ranges, so that the annealed strip has more suitable toughness and strength, thereby having better processing performance (not prone to slagging and breakage during processing), and thus preparing a motor stator with better quality; at the same time, it can also make the strip have the advantage of lower iron loss after annealing, so that the prepared motor stator has better power and efficiency.

[0012] In some optional embodiments, in the blanking step, the material of the blanking die includes tungsten steel, and / or the blanking pressure is 250-300 MPa.

[0013] In the above technical solution, the yield strength of the strip of amorphous soft magnetic alloy in the embodiment of the present application is higher than the yield strength of conventional silicon steel. A blanking die of a specific material is used and the blanking pressure is limited to a specific range, which is convenient for punching and can reduce the risk of burrs on the strip during the blanking process (fewer burrs, and the iron loss of the corresponding material is usually smaller), so that the prepared motor stator has better power and efficiency, and at the same time, the blanking die can have a longer service life.

[0014] In some optional embodiments, the surface of the punching die further has a wear-resistant coating, the material of the wear-resistant coating includes TiCN, and / or the thickness of the wear-resistant coating is 1 to 7 μm.

[0015] In the above technical solution, a TiCN wear-resistant coating with a specific thickness range is provided on the surface of the punching die, wherein TiCN combines the high hardness of TiC and the high toughness of TiN, so that the punching die has relatively excellent wear resistance, thereby making the punching die have a longer service life.

[0016] In some optional embodiments, in the first lamination and composite processing step, glue bonding is used to connect two adjacent punching sheet precursors, and / or the thickness of the punching sheet is 0.2 to 0.3 mm.

[0017] In the above technical solution, the glue bonding method is convenient for batch implementation, which helps the industrialization of the technical solution; at the same time, the thickness of the punching sheet is limited to a specific range (the existing silicon steel punching sheet is usually also within this thickness range), which helps to adapt to the existing preparation process.

[0018] In some optional embodiments, the material of the glue is selected from at least one of epoxy resin and acrylic resin, and / or the glue is a heat-curing glue and the curing time is no longer than 120 seconds.

[0019] In the above technical solution, epoxy resin and acrylic resin glues have the advantages of being widely available and easy to prepare. At the same time, the use of heat-curing glues and glues with a short curing time helps to improve preparation efficiency, thereby facilitating industrialization.

[0020] In some optional embodiments, the melting point of the glue is not less than 150° C., and / or the bonding strength of the glue is not less than 2 MPa.

[0021] In the above technical solution, glue with a high melting point and bonding strength is used (the motor will generate heat during high-speed operation, and glue with a high melting point and high bonding strength is not easy to fail), so that the motor has higher structural stability during high-speed operation.

[0022] In a third aspect, an embodiment of the present application provides a motor, comprising a motor stator and a motor rotor as provided in the embodiment of the first aspect.

[0023] In the above technical solution, the motor includes a motor stator as provided in the embodiment of the first aspect. Since the motor stator adopts a material with high saturation magnetic induction intensity, low magnetic loss and good plasticity, the motor has higher power and efficiency, thereby making the electric vehicle have a longer endurance, thereby meeting the user's demand for high-performance electric drive systems.

[0024] In some optional embodiments, the outer peripheral wall of the motor rotor is provided with a carbon fiber wrapping layer.

[0025] In the above technical solution, a carbon fiber wrapping layer is provided on the outer peripheral wall of the motor rotor, which can effectively reduce the noise generated by the motor stator during operation. At the same time, it also helps to increase the power of the motor. In addition, due to the presence of the carbon fiber wrapping layer, the structural strength of the motor can be improved, thereby increasing the speed of the motor.

[0026] In some optional embodiments, the thickness of the carbon fiber wrapping layer is 0.7-1.8 mm.

[0027] In the above technical solution, limiting the thickness of the carbon fiber wrapping layer within a specific range can achieve a better noise reduction effect, and at the same time, can better improve the power and speed of the motor.

[0028] In a fourth aspect, an embodiment of the present application provides an electric drive system, comprising a motor as provided in the embodiment of the third aspect.

[0029] In a fifth aspect, an embodiment of the present application provides an automobile, comprising an electric drive system as provided in the embodiment of the fourth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 A process flow chart of a method for preparing a motor stator provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] To make the purpose, technical solutions and advantages of the examples of the present application clearer, the technical solutions in the examples of the present application will be described clearly and completely below. Where specific conditions are not specified in the examples, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0033] It should be noted that “and / or” in this application, such as “Feature 1 and / or Feature 2”, refers to three situations: “Feature 1” alone, “Feature 2” alone, or “Feature 1” plus “Feature 2”.

[0034] In addition, in the description of this application, unless otherwise specified, the meaning of "multiple" in "one or more" refers to two or more; the range of "value a to value b" includes the two end values ​​"a" and "b", and the "unit of measurement" in "value a to value b+unit of measurement" represents the "unit of measurement" of both "value a" and "value b".

[0035] The following is a detailed description of a motor stator and its preparation method, a motor, an electric drive system, and a vehicle in accordance with an embodiment of the present application.

[0036] In a first aspect, the present invention provides a motor stator, wherein the material of the motor stator includes an amorphous soft magnetic alloy, and the molecular formula of the amorphous soft magnetic alloy is: Fe a Si b B c Cu d Co e M f , wherein M is selected from at least one of Zr, Hf and Nb, 70≤a≤85, 0.65≤b≤8.5, 0.5≤c≤6, 0.7≤d≤2.5, 0.25≤e≤5, 2.5≤f≤8, and satisfies a+b+c+d+e+f=100.

[0037] In this application, an amorphous soft magnetic alloy with a specific molecular formula has the characteristics of high saturation magnetic induction intensity, low magnetic loss and good plasticity. This material is introduced into the field of electric drive systems and used as the main material for manufacturing motor stators, so that the corresponding motor has higher power and efficiency, thereby making electric vehicles have longer endurance, to meet users' needs for high-performance electric drive systems.

[0038] In a second aspect, an embodiment of the present application provides a method for preparing a motor stator as provided in the embodiment of the first aspect, comprising the following steps:

[0039] A strip material made of amorphous soft magnetic alloy and having a thickness of 0.02 to 0.03 mm (for example, but not limited to, a thickness of 0.02 mm, 0.021 mm, 0.022 mm, 0.023 mm, 0.024 mm, 0.025 mm, 0.026 mm, 0.027 mm, 0.028 mm, 0.029 mm, and 0.03 mm) is provided; the strip material is annealed at a temperature not higher than 370°C to obtain a punching sheet precursor; a plurality of punching sheet precursors are subjected to a first lamination and composite treatment to connect the plurality of punching sheet precursors into a whole to obtain a punching sheet; the punching sheets are blanked to obtain a motor stator precursor; the plurality of motor stator precursors are subjected to a second lamination and composite treatment to connect the plurality of motor stator precursors into a whole to obtain a motor stator.

[0040] In the present application, according to a specific process, a thin sheet of amorphous soft magnetic alloy material with advantages such as high saturation magnetic induction intensity, low magnetic loss and good plasticity can be prepared into a motor stator, so that the corresponding motor has higher power and speed; wherein, when the strip is of a specific material and the thickness is within a specific range, the annealing temperature is set within a range not higher than 370°C, which can make the strip have relatively excellent toughness and strength after annealing, so that the strip has better processing performance (that is, improving the problem of slagging or even breakage of the strip during subsequent processing), and thus the motor stator prepared from the strip of this specific material and specific thickness has higher power and efficiency.

[0041] It should also be noted that amorphous soft magnetic alloy materials are currently mostly used in transformer-related fields, and the treatment temperature of the materials during the annealing process is generally higher than the material's crystallization temperature. In this application, the inventors discovered that if the treatment temperature is set according to the conventional annealing process, the material after annealing is relatively brittle and difficult to process subsequently, that is, it is difficult to prepare motor stators through subsequent processes. Therefore, the inventors innovatively adopted the annealing process below the material's crystallization temperature.

[0042] In addition, the inventors also found that the temperature of the annealing treatment is closely related to the iron loss of the material after annealing, and the iron loss is related to the power and efficiency of the corresponding motor. Based on this, the relevant parameters of the annealing treatment can be further optimized.

[0043] As an example, in the annealing step, the processing temperature is 180-320°C, for example but not limited to the processing temperature being any one of 180°C, 200°C, 220°C, 240°C, 260°C, 280°C, 300°C and 320°C, or a range between any two of them; the processing time is 60-200s, for example but not limited to the processing time being any one of 60s, 80s, 100s, 120s, 140s, 160s, 180s and 200s, or a range between any two of them.

[0044] In this embodiment, the processing temperature and time during the annealing process are limited to specific ranges, so that the strip after annealing has more suitable toughness and strength, thereby having better processing performance (not prone to slagging and breakage during processing), and thus preparing a motor stator with better quality; at the same time, it can also make the strip have the advantage of lower iron loss after annealing, so that the prepared motor stator has better power and efficiency.

[0045] As an example, in the blanking process, the material of the blanking die includes tungsten steel, and / or the blanking pressure is 250-300 MPa, for example but not limited to any one of 250 MPa, 260 MPa, 270 MPa, 280 MPa, 290 MPa and 300 or a range between any two of them.

[0046] In this embodiment, the yield strength of the strip of amorphous soft magnetic alloy material in the embodiment of the present application is higher than the yield strength of conventional silicon steel. A blanking die of a specific material is used and the blanking pressure is limited to a specific range, which facilitates the forming of the punching sheet and can reduce the risk of burrs on the strip during the blanking process (fewer burrs, and the iron loss of the corresponding material is usually smaller), so that the prepared motor stator has better power and efficiency, and at the same time, the blanking die can have a longer service life.

[0047] As an example, the surface of the blanking die also has a wear-resistant coating, the material of the wear-resistant coating includes TiCN, and / or the thickness of the wear-resistant coating is 1 to 7 μm, for example but not limited to the thickness of the coating is any point value of 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm and 7 μm or a range value between any two of them.

[0048] In this embodiment, a TiCN wear-resistant coating within a specific thickness range is provided on the surface of the punching die, wherein TiCN combines the high hardness of TiC and the high toughness of TiN, so that the punching die has relatively excellent wear resistance, thereby making the punching die have a longer service life.

[0049] As an example, in the first lamination and composite processing step, glue bonding is used to connect two adjacent punching sheet precursors, and / or the thickness of the punching sheet is 0.2 to 0.3 mm.

[0050] In this embodiment, the glue bonding method is convenient for batch implementation, which helps the industrialization of this technical solution; at the same time, the thickness of the punching sheet is limited to a specific range (the existing silicon steel punching sheet is usually also within this thickness range), which helps to adapt to the existing preparation process.

[0051] It should be noted that the method of gluing the punching sheet precursor is not limited and can be carried out according to conventional processes in the art, for example, vacuum dipping or surface gluing can be used.

[0052] As an example, the material of the glue is selected from at least one of epoxy resin and acrylic resin, and / or the glue is a heat-curing glue and the curing time is not longer than 120s, for example, it can be any point value of 50s, 60s, 70s, 80s, 90s, 100s, 110s and 120s or a range value between any two of them.

[0053] In this embodiment, epoxy resin and acrylic resin glues have the advantages of being widely available and easy to prepare. At the same time, the use of heat-curing glues and glues with a short curing time helps to improve preparation efficiency, thereby facilitating industrialization.

[0054] As an example, the melting point of the glue is not lower than 150°C, for example, the melting point can be any one of 150°C, 170°C, 200°C, 220°C and 240°C, or a range between any two of them; and / or, the bonding strength of the glue is not lower than 2MPa, for example, it can be any one of 2MPa, 3MPa, 4MPa, 5MPa and 6MPa, or a range between any two of them.

[0055] In this embodiment, glue with a high melting point and bonding strength is used (the motor will generate heat during high-speed operation, and glue with a high melting point and high bonding strength is not easy to fail), so that the motor has higher structural stability during high-speed operation.

[0056] It should be noted that the second lamination process is not limited to a specific method and can be performed in accordance with conventional methods in the art, such as by point connection, welding or gluing.

[0057] It should be noted that any process or step not specifically described or limited in the motor stator preparation process may be configured according to conventional selections in the art.

[0058] As an example, the process flow chart of the method for preparing the motor stator is shown in FIG. Figure 1 .

[0059] In a third aspect, an embodiment of the present application provides a motor, comprising a motor stator and a motor rotor as provided in the embodiment of the first aspect.

[0060] In the present application, the motor includes a motor stator as provided in the first aspect embodiment. Since the motor stator is made of a material with high saturation magnetic induction intensity, low magnetic loss and good plasticity, the motor has higher power and efficiency, thereby making the electric vehicle have a longer endurance, thereby meeting the user's demand for high-performance electric drive systems.

[0061] As an example, the material of the motor rotor is conventional silicon steel.

[0062] It should be noted that the inventors have found that when the material of the motor stator adopts the specific material provided in the embodiment of the present application, the assembled motor has a large noise problem during operation. Based on this, the structure of the motor can be optimized.

[0063] As an example, the outer peripheral wall of the motor rotor is provided with a carbon fiber wrapping layer.

[0064] In this embodiment, a carbon fiber wrapping layer is provided on the outer peripheral wall of the motor rotor, which can effectively reduce the noise generated by the motor stator during operation. At the same time, it also helps to increase the power of the motor. In addition, the presence of the carbon fiber wrapping layer can also improve the structural strength of the motor, thereby increasing the speed of the motor.

[0065] As an example, the thickness of the carbon fiber wrapping layer is 0.7 to 1.8 mm, for example, but not limited to, the thickness is any point value among 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm and 1.8 mm, or a range value between any two of them.

[0066] In this embodiment, limiting the thickness of the carbon fiber wrapping layer to a specific range can achieve a better noise reduction effect and, at the same time, can better improve the power and speed of the motor.

[0067] It should be noted that the material of the carbon fiber wrapping layer is not limited, for example, it can be T800 or T600 carbon fiber material.

[0068] It should be noted that any structural or functional unit in the motor that is not specifically described or limited may be configured according to conventional options in the art.

[0069] In a fourth aspect, an embodiment of the present application provides an electric drive system, comprising a motor as provided in the embodiment of the third aspect.

[0070] In a fifth aspect, an embodiment of the present application provides an automobile, comprising an electric drive system as provided in the embodiment of the fourth aspect.

[0071] The features and performance of the present application are further described in detail below with reference to the embodiments.

[0072] Example 1

[0073] The present invention provides a method for manufacturing a motor, comprising the following steps:

[0074] Preparation of motor stator:

[0075] Provide a strip made of amorphous soft magnetic alloy with a single sheet thickness of 0.02mm, wherein the molecular formula of the amorphous soft magnetic alloy is Fe 80Si6B4Cu 1.5 Co 3.5 Zr5, the strip is heat-insulated and annealed at 240°C for 120s to obtain a punching sheet precursor; 10 sheets of the punching sheet precursor are stacked by vacuum dipping, wherein the glue is made of epoxy resin, has a curing time of 100s, a melting point of 200°C, and a bonding strength of 5MPa, to obtain a punching sheet with a thickness of 0.2mm; a punching die made of tungsten steel (with a 5μm thick TiCN wear-resistant coating on the surface) is used to punch the sheet (punching pressure is 280MPa) to obtain a motor stator precursor; 20 sheets of the motor stator precursor are stacked by buckle point connection to obtain a motor stator.

[0076] Motor assembly:

[0077] The motor rotor is made of silicon steel, and the outer peripheral wall includes a carbon fiber wrapping layer made of T800 material and 1.2 mm thick. The motor stator and the motor rotor are assembled into a motor.

[0078] Example 2

[0079] The embodiment of the present application provides a method for preparing a motor, which differs from Example 1 only in that the strip is subjected to heat preservation annealing at 320° C. for 120 seconds to obtain a punching sheet precursor.

[0080] Example 3

[0081] The embodiment of the present application provides a method for preparing a motor, which differs from Example 1 only in that the strip is subjected to heat preservation annealing at 360° C. for 120 seconds to obtain a punching sheet precursor.

[0082] Example 4

[0083] This embodiment of the present application provides a method for manufacturing a motor, which differs from Example 1 only in that:

[0084] The outer peripheral wall of the motor rotor is not covered with carbon fiber.

[0085] Comparative Example 1

[0086] The comparative example of the present application provides a method for preparing a motor, which differs from Example 1 only in that:

[0087] The motor stator is made of silicon steel.

[0088] Comparative Example 2

[0089] The comparative example of the present application provides a method for preparing a motor, which differs from Example 1 only in that:

[0090] The motor stator is made of silicon steel, and the outer wall of the motor rotor is not wrapped with a carbon fiber layer.

[0091] Test example

[0092] Motor performance test

[0093] Test method:

[0094] The motors prepared in Examples 1 to 4 and Comparative Examples 1 to 2 were numbered respectively, and then the core iron loss, motor efficiency, speed limit and noise of each motor were tested, and the test results were statistically summarized in Table 1.

[0095] Specifically, the test steps for the motor core iron loss are as follows:

[0096] The test is carried out in accordance with the requirements of the national standard GB / T 20835-2024 Generator stator core magnetization test guide.

[0097] Specifically, the test steps for motor efficiency are as follows:

[0098] The test is carried out in accordance with the requirements of 6.3.8 of the national standard GB-T 18488-2024 for electric vehicle drive motor systems.

[0099] Specifically, the test steps for the upper limit of the motor speed are as follows:

[0100] The test is carried out in accordance with the requirements of 6.3.7 of the national standard GB-T 18488-2024, "Drive Motor Systems for Electric Vehicles".

[0101] Specifically, the test steps for motor noise are as follows:

[0102] The test is carried out in accordance with the requirements of the national standard GB-T 10069.3-2024, determination method and limit of noise of rotating electrical machines.

[0103] Table 1

[0104]

[0105] Referring to Table 1, it can be seen from the test results of Examples 1 to 3 and Comparative Example 1 that in the embodiments of the present application, an amorphous soft magnetic alloy strip of a specific material and thickness is used as the substrate, and the motor stator is prepared according to a specific annealing process. Compared with the conventional silicon steel used to prepare the motor stator, the former corresponds to a motor with higher power and efficiency.

[0106] The test results of Examples 1 to 3 show that when the material and thickness of the substrate are constant, controlling the annealing temperature within a specific range results in smaller core loss in the motor and higher power and efficiency than exceeding the temperature range.

[0107] From the test results of Examples 1 to 3 and Example 4, Comparative Example 1 and Comparative Example 2, it can be seen that coating the motor stator with a carbon fiber wrapping layer helps to reduce the noise of the motor during operation, and at the same time, helps to increase the power of the motor and the upper limit of the motor speed.

[0108] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

Claims

1. A method for preparing a motor stator, characterized in that: The following steps are involved: A strip material made of amorphous soft magnetic alloy and having a thickness of 0.02-0.03 mm is provided; wherein the molecular formula of the amorphous soft magnetic alloy is: Fe a Si b B c Cu d Co e M f , wherein M is selected from at least one of Zr, Hf and Nb, 70≤a≤85, 0.65≤b≤8.5, 0.5≤c≤6, 0.7≤d≤2.5, 0.25≤e≤5, 2.5≤f≤8, and satisfies a+b+c+d+e+f=100; Annealing the strip at a temperature not higher than 370° C. to obtain a sheet precursor; Performing a first lamination and compounding process on the plurality of punching sheet precursors so as to connect the plurality of punching sheet precursors into a whole to obtain punching sheets; Punching the punching sheet to obtain a motor stator precursor; The plurality of motor stator precursors are subjected to a second lamination composite process so that the plurality of motor stator precursors are connected into a whole to obtain the motor stator.

2. The method for preparing a motor stator according to claim 1, wherein: In the annealing step, the treatment temperature is 180-320° C., and the treatment time is 60-200 s.

3. The method for preparing a motor stator according to claim 1, wherein: In the step of blanking, the material of the blanking die includes tungsten steel, and / or the blanking pressure is 250-300 MPa.

4. The method for preparing a motor stator according to claim 3, wherein: The surface of the punching die further has a wear-resistant coating, the material of the wear-resistant coating includes TiCN, and / or the thickness of the wear-resistant coating is 1-7 μm.

5. The method for preparing a motor stator according to any one of claims 1 to 4, characterized in that: In the first lamination and composite processing step, the connection between two adjacent punching sheet precursors is achieved by gluing, and / or the thickness of the punching sheet is 0.2-0.3 mm.

6. The method for preparing a motor stator according to claim 5, wherein: The material of the glue is selected from at least one of epoxy resin and acrylic resin, and / or the glue is a heat-curing glue and the curing time is no longer than 120 seconds.

7. The method for preparing a motor stator according to claim 6, wherein: The melting point of the glue is not lower than 150° C., and / or the bonding strength of the glue is not lower than 2 MPa.

8. A motor, characterized in that: The invention comprises a motor stator and a motor rotor prepared by the preparation method according to any one of claims 1 to 7.

9. The motor according to claim 8, characterized in that The outer peripheral wall of the motor rotor is provided with a carbon fiber wrapping layer.

10. The motor according to claim 9, wherein The thickness of the carbon fiber wrapping layer is 0.7-1.8 mm.

11. An electric drive system, characterized in that: The method comprises the motor according to any one of claims 8 to 10.

12. An automobile, characterized in that: Comprising the electric drive system as claimed in claim 11.

Images