Flat wire for electric motor, stator, electric motor, and vehicle

Abstract

A flat wire (100) for an electric motor, a stator (300), an electric motor (400), and a vehicle (500). In a direction perpendicular to the extension direction of the flat wire (100), the flat wire (100) has a width direction and a thickness direction, the flat wire comprises a flat wire body (10), the dimension of the flat wire body (10) in the thickness direction is defined as δ, the dimension of the flat wire body (10) in the width direction is defined as ω, and the elastic modulus of the flat wire body (10) is defined as E, satisfying: δ∈{2(1+η) Formula (I), 6[(1+η) Formula (I)]}, where μ is 0.5 in Gpa / mm; and η is 0.1, which is a dimensionless quantity.

Description

Flat wires used in motors, stators, motors, and vehicles.

[0001]

[0002] Cross-reference to related applications

[0003] This disclosure is based on and claims priority to Chinese Patent Application No. 2024117557660, filed on November 29, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0004] This disclosure relates to the field of motor technology, specifically to a flat wire, stator, motor, and vehicle for use in motors. Background Technology

[0005] With the rapid development of new energy vehicle technology, the performance requirements for automotive motors are becoming increasingly stringent. While continuously pursuing high slot fill factor, high power density, and high torque density, round wire motors have struggled to overcome the bottlenecks imposed by current performance demands on drive motors. Flat wire motors, on the other hand, can achieve performance requirements that round wire motors cannot meet. They offer high slot fill factor, high power density, and excellent heat dissipation and NVH performance. Furthermore, they can significantly reduce the height of the motor winding ends, decrease copper usage, and reduce winding copper losses, thereby improving the efficiency of automotive drive motors.

[0006] However, motors have a certain degree of vibration, and vehicles will also encounter different vibration road conditions during operation. Consequently, the flat wire body will also vibrate, resulting in significant stress within the vibrating flat wire body, which can lead to loosening, deformation, or even damage. Summary of the Invention

[0007] This disclosure aims to at least address one of the technical problems existing in the prior art. To this end, the disclosure provides a flat wire for an electric motor that has high strength, thereby reducing stress concentration.

[0008] The flat wire for an electric motor according to a first aspect embodiment of this disclosure has a width direction and a thickness direction in an extension direction perpendicular to the flat wire. The flat wire includes a flat wire body, the dimension of the flat wire body in the thickness direction is δ, the dimension of the flat wire body in the width direction is ω, and the elastic modulus of the flat wire body is E, satisfying:

[0009] δ∈{2(1+η) ,6[2(1+η) ]},

[0010] Where μ is 0.5, and the unit is Gpa / mm; η is 0.1, which is a dimensionless quantity; ω is in mm; δ is in mm; and E is in Gpa.

[0011] According to embodiments of this disclosure, by designing the flat wire body and determining the optimal relationship between width ω, thickness δ, and elastic modulus E, the flat wire experiences less stress under vibration conditions. This is a key technology that balances mechanical performance and lightweight design, while also improving space utilization and making the system more compact.

[0012] According to an embodiment of this disclosure, along the length direction of the flat wire, the flat wire includes a first connecting segment, a first extension segment, a transition segment, a second extension segment, and a second connecting segment connected in sequence. The first extension segment and the transition segment are connected by radial bending in the width direction of the flat wire, and the second extension segment and the transition segment are connected by radial bending in the thickness direction of the flat wire. There is an angle between the extension lines of the first extension segment and the second extension segment.

[0013] According to embodiments of this disclosure, the angle between the first connecting segment and the first extension segment is an obtuse angle; and / or, the angle between the extension line of the first extension segment and the extension line of the second extension segment is an obtuse angle; and / or, the angle between the second connecting segment and the second extension segment is an obtuse angle.

[0014] According to an embodiment of this disclosure, the first connecting segment and the second connecting segment define a plane, and the angle between the extension line of the first extension segment and the extension line of the second extension segment projected onto the plane is θ, satisfying: 90°≤θ≤150°.

[0015] According to an embodiment of this disclosure, the bending radius of the first extension segment and the transition segment is R1, satisfying: R1≥ω.

[0016] According to an embodiment of this disclosure, the bending radius of the second extension segment and the transition segment is R2, satisfying: R1≥δ.

[0017] According to embodiments of this disclosure, the device further includes a first pin and a second pin. The first pin is located at one end of the first connecting segment away from the first extension segment, and the second pin is located at one end of the second connecting segment away from the second extension segment. The first pin and the second pin are bent away from each other, or the first pin and the second pin are bent to the same side.

[0018] According to an embodiment of this disclosure, the wrapping layer includes a base layer that wraps around the outside of the flat wire body, and the base layer has a coating.

[0019] According to embodiments of this disclosure, the thickness of the coating is between 0.006 mm and 0.012 mm.

[0020] According to embodiments of this disclosure, the wrapping layer further includes an insulating layer that wraps around the outside of the underlayment.

[0021] According to embodiments of this disclosure, the elastic modulus E of the flat wire body is 55 GPa-125 GPa.

[0022] According to embodiments of this disclosure, the material of the flat wire body includes aluminum and at least one of the following: silicon, iron, magnesium, boron, copper, manganese, zinc and titanium.

[0023] According to embodiments of this disclosure, the yield strength of the flat wire body is ≥65MPa; and / or, the tensile strength of the flat wire body is ≥110MPa.

[0024] The second aspect of this disclosure provides a stator comprising a stator core and a flat wire winding, the flat wire winding being formed using the flat wire winding method for motors described in the first aspect of this disclosure.

[0025] A third aspect of this disclosure provides an electric motor including the stator described in the second aspect of this disclosure.

[0026] This disclosure provides a fourth aspect of a vehicle that includes the motor described in the second aspect of this disclosure.

[0027] Additional aspects and advantages of this disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this disclosure. Attached Figure Description

[0028] The above and / or additional aspects and advantages of this disclosure will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0029] Figure 1 is a schematic diagram of the flat wire before installation according to an embodiment of the present disclosure;

[0030] Figure 2 is a schematic diagram of the flat wire after installation according to an embodiment of the present disclosure;

[0031] Figure 3 is a partial structural schematic diagram of a flat wire according to an embodiment of the present disclosure;

[0032] Figure 4 is a cross-sectional view with flat lines according to an embodiment of the present disclosure;

[0033] Figure 5 is a schematic diagram of a flat wire winding according to an embodiment of the present disclosure;

[0034] Figure 6 is a schematic diagram of a stator according to an embodiment of the present disclosure;

[0035] Figure 7 is a schematic diagram of a vehicle according to an embodiment of the present disclosure.

[0036] Figure label:

[0037] Flat wire 100, flat wire winding 200, stator 300, stator core 310, motor 400, vehicle 500.

[0038] Flat wire body 10, sheathing layer 20, undercoat 21, coating layer 211, insulation layer 22.

[0039] First connecting segment 1, first extension segment 2, transition segment 3, second extension segment 4, second connecting segment 5, first pin 6, second pin 7. Embodiments of the present invention

[0040] The embodiments of this disclosure are described in detail below. The embodiments described below are exemplary and are only used to explain this disclosure, and should not be construed as limiting this disclosure.

[0041] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Furthermore, in the description of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0042] The endpoints and any values ​​of the ranges disclosed in this disclosure are not limited to the precise ranges or values, and such ranges or values ​​should be understood to include values ​​close to such ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in this disclosure.

[0043] In this disclosure, the terms “comprising” or “including” are open-ended expressions, meaning that they include the contents specified in this disclosure but do not exclude other contents.

[0044] For the flat wire of the motor, numerous factors influence its stress performance. Based on the Design of Experiments (DOE), the present inventor optimized and screened stress response factors and key factors. Simulation tests were conducted using the flat wire body with a three-dimensional structure as shown in Figure 1 as the experimental object to obtain the stress cloud map of the flat wire body. Extensive testing was conducted, and the relationship between influencing factors such as the coefficient of thermal expansion, aging temperature, aging time, and elastic modulus E and the maximum stress of the flat wire body was specifically studied. Some experimental results are statistically shown in Tables 1 to 4. The material of the flat wire body is aluminum alloy. The motor alloy was prepared as follows: each raw material component of the aluminum alloy was taken, and solution treatment and aging treatment were performed to obtain the aluminum alloy. The specific testing method for the simulation test was as follows: the parameters of the flat wire body and the parameters of the vibration experiment were imported into the finite element analysis element to conduct a simulation experiment on the flat wire body. The vibration experiment parameters included: vibration time 22h, broadband frequency 10Hz~1000Hz, and vibration condition RMS (Root Mean Square, effective value of vibration velocity): 27.8m / s. 2 The working conditions must be such that there is no mechanical damage or loosening after the test.

[0045] Table 1

[0046]

[0047] Table 2

[0048]

[0049] Table 3

[0050]

[0051] Table 4

[0052]

[0053] As shown in Tables 1-4, when the elastic modulus is the factor and the key factor of stress response, the factor has a significant impact, while the factors of expansion coefficient, aging temperature, and aging time have no significant impact on stress.

[0054] The elastic modulus is a metric used to measure an object's resistance to elastic deformation. From a microscopic perspective, it reflects the strength of bonds between atoms, ions, or molecules, and is denoted by E. E is expressed as the force per unit area (σ), and its unit is N / m². 2 (MPa or Gpa).

[0055] When the length of the flat wire body is determined, the range of selectable thickness δ of the flat wire body varies when materials with different elastic moduli E are used as the flat wire body. The inventors have designed a reasonable relationship between the flat wire body width ω and the flat wire body thickness δ to improve the strength of the flat wire, reduce stress, and thus make the motor system more compact and lighter.

[0056] Therefore, using a flat wire body with a three-dimensional structure as the experimental object, optimization was carried out based on DOE (Design of Experiments) to screen stress response factors and key factors. Extensive testing and specific verification were conducted, as shown in Figures 1-4. This disclosure proposes an embodiment of a flat wire 100 for a motor 400. In the extension direction perpendicular to the flat wire 100, the flat wire 100 has a width direction F1 and a thickness direction F2. The flat wire 100 includes a flat wire body 10 and a wrapping layer 20. The dimension of the flat wire body 10 in the thickness direction F2 is δ, the dimension of the flat wire body 10 in the width direction F1 is ω, and the elastic modulus of the flat wire body 10 is E, satisfying:

[0057] δ∈{2(1+η) ,6[2(1+η) ]

[0058] Where η is 0.1, and is a dimensionless quantity.

[0059] Here, δ is in mm; ω is in mm; and E is in GPa.

[0060] It should be noted that the flat wire body 10 here is perpendicular to the extension direction of the flat wire 100 in the thickness direction F2 and the width direction F3. For example, the flat wire 100 extends along the X direction, and the thickness direction F2 and the width direction F3 are perpendicular to the X direction. The relationship between the size δ of the flat wire body 10 in the thickness direction F2 and the size ω of the flat wire body 10 in the width direction F1 is not limited. δ can be greater than ω, less than ω, or equal to ω.

[0061] By designing the width, thickness, and elastic modulus of the flat wire body 10 using the above formulas, when the width ω of the flat wire body 10 is determined, and materials with different elastic moduli E are used as the flat wire body 10, the thickness δ of the flat wire body 10 is adjusted accordingly. This can improve the strength of the flat wire body 10, reduce stress, and the structure can meet the requirements of miniaturization and lightweighting, thereby increasing the power density.

[0062] According to the embodiments of the present disclosure, the flat wire 100 for the motor 400, through the design of the flat wire body 10, determines the optimal relationship between the width ω, thickness δ, and elastic modulus E, so that the flat wire 100 has low stress under vibration conditions. This is a key technology for balancing mechanical performance and lightweight design. At the same time, the flat design can fill the stator slots more compactly, improve the slot fill factor, thereby improving space utilization, increasing the power density and efficiency of the motor 400, and facilitating the miniaturization design of the motor 400.

[0063] As shown in Figures 1-4, according to an embodiment of this disclosure, along the length direction of the flat wire 100, the flat wire 100 includes a first connecting segment 1, a first extension segment 2, a transition segment 3, a second extension segment 4, and a second connecting segment 5 connected sequentially. The first extension segment 2 and the transition segment 3 are connected by radial bending with the width direction F1 of the flat wire 100 as the connecting direction, and the second extension segment 4 and the transition segment 3 are connected by radial bending with the thickness direction F2 of the flat wire 100 as the connecting direction. That is, the bending direction of the first extension segment 2 relative to the transition segment 3 is along the width direction of the flat wire 100, and the bending direction of the second extension segment 4 relative to the transition segment 3 is along the thickness direction of the flat wire 100. The bending directions of the two extension segments relative to the transition segment 3 are different, thereby forming a three-dimensional structure in space. There is an angle between the extension lines of the first extension segment 2 and the second extension segment 4, thereby forming a model of the flat wire 100. The first connecting segment 1 and the second connecting segment 5 can be embedded in the stator slot. The extension direction can be changed by the first extension segment 2 and the second extension segment 4, and multiple flat wires 100 can be distributed and extended in various combinations.

[0064] The first connecting section 1, the first extension section 2, the transition section 3, the second extension section 4, and the second connecting section 5 are integrally formed, thereby improving the strength of the flat wire 100 and improving the installation accuracy of the flat wire 100.

[0065] According to an embodiment of this disclosure, the angle between the first connecting segment 1 and the first extension segment 2 is an obtuse angle, which can reduce stress concentration and reduce the probability of fatigue cracking of the flat wire 100.

[0066] According to an embodiment of this disclosure, the angle between the extension line of the first extension segment 2 and the extension line of the second extension segment 4 is an obtuse angle, which can reduce the problem of stress concentration and reduce the probability of fatigue cracking of the flat wire 100.

[0067] According to an embodiment of this disclosure, the angle between the second extension segment 4 and the second connecting segment 5 is an obtuse angle, which can reduce stress concentration and reduce the probability of fatigue cracking of the flat wire 100.

[0068] As shown in Figure 3, according to an embodiment of this disclosure, the first connecting segment 1 and the second connecting segment 5 define a plane. The angle between the extension line of the first extension segment 2 and the extension line of the second extension segment 4 projected onto the plane is θ, which satisfies: 90°≤θ≤150°. When θ is too small, the angle formed between the first extension segment 2 and the second extension segment 4 is too small. Under variable stress conditions, stress concentration will occur at the point where the cross-sectional dimensions change abruptly, which is prone to fatigue strength failure. In order to improve fatigue strength, stress concentration sources and stress concentration degree should be reduced as much as possible.

[0069] Due to the flat design, the large θ results in an excessively large radial distance along the stator assembly after welding the first and second legs of adjacent flat wires, depending on the winding method. This prevents more compact filling, thus reducing space utilization and negatively impacting the motor's power density and efficiency, as well as its miniaturization design.

[0070] By limiting θ to between 90° and 150°, θ can be any value among 90°, 100°, 110°, 120°, 130°, 140°, and 150° or any value between two of them. This can reduce stress concentration, lower the probability of fatigue cracking in flat wire 100, and improve space utilization.

[0071] As shown in Figure 4, according to the embodiment of this disclosure, since the first extension segment 2 and the transition segment 3 are connected by radial bending in the width direction F1 of the flat line 100, the bending radius of the first extension segment 2 and the transition segment 3 is R1, which satisfies: R1≥ω, thereby reducing the curvature at the connection between the first extension segment 2 and the transition segment 3 and reducing the stress concentration.

[0072] As shown in Figure 4, according to the embodiment of this disclosure, since the second extension segment 4 and the transition segment 3 are connected by radial bending in the thickness direction F2 of the flat wire 100, the bending radius of the second extension segment 4 and the transition segment 3 is R2, which satisfies: R1≥δ, thereby reducing the curvature at the connection between the second extension segment 4 and the transition segment 3 and reducing the stress concentration.

[0073] As shown in Figure 2, according to an embodiment of the present disclosure, the flat wire 100 further includes a first pin 6 and a second pin 7. The first pin 6 is located at the end of the first connecting segment 1 away from the first extension segment 2, and the second pin 7 is located at the end of the second connecting segment 5 away from the second extension segment 4. The first pin 6 and the second pin 7 are bent away from each other, or the first pin 6 and the second pin 7 are bent to the same side, thereby facilitating the connection of adjacent flat wires 100. The ends of the first pin 6 and the second pin 7 are provided with chamfers, and providing chamfers at the ends of the pins can also reduce stress concentration.

[0074] Specifically, the forming of the flat wire 100 includes: stamping a straight flat wire 100 with a high aspect ratio into a new type of flat wire 100 with a first connecting section 1, a first extension section 2, a transition section 3, a second extension section 4, and a second connecting section 5 in one stamping process using a stamping forming equipment; then twisting the tail ends of the first connecting section 1 and the second connecting section 5 of the flat wire 100 radially along the stator 300 assembly according to different winding methods to form a first pin 6 and a second pin 7; and welding the first pin and the second pin of adjacent flat wires 100.

[0075] In related technologies, the impact on material surface properties mainly includes three aspects: optimization of the material's surface microstructure, introduction of residual compressive stress field, and increase in surface roughness. Due to the large number of high-speed, continuous projectiles impacting the material surface during surface strengthening jetting, much like countless small hammers striking the surface, some kinetic energy is absorbed by the material's surface, forming indentations at the impact points. Within a certain depth around these indentations, intense plastic deformation occurs, forming a plastic deformation layer of a certain thickness. Within this layer, the material's microstructure changes, exhibiting grain refinement, increased dislocation density, and micro-distortion. This phenomenon leads to the formation of subgrain structures within the deformation layer. In some cases, the phase structure of the material even changes; this strengthening is called microstructural strengthening. Microstructural strengthening makes it difficult for crystals within the deformation layer to slip, and simultaneously prevents slippage at the interface between the deformation-strengthened layer and the interior. Normally, fatigue cracks initiate on the surface of a part, while structural strengthening can prevent the initiation of fatigue cracks on the material surface, thereby extending the nucleation life of fatigue cracks and improving the service life of the material.

[0076] During the surface strengthening process, not only is the surface structure of the material optimized, but also a residual compressive stress layer of a certain thickness is introduced into the deformation layer under the action of cyclic plastic deformation. The introduction of the residual compressive stress layer can drive surface cracks from the surface layer to the subsurface layer, effectively reducing the tensile stress generated by external forces or moments on the surface. When the depth of the residual stress exceeds the depth of the microcrack, it can effectively prevent and reduce the propagation rate of fatigue cracks. Therefore, for parts with microcracks or notches, the strengthening effect of residual stress is better than that of microstructure strengthening. Thus, pre-compressive stress can be generated on the surface of the flat wire body 10, improving the fatigue resistance of the flat wire 100. Since the lower the surface roughness, the lower the fatigue strength, and at the same time, the surface strengthening treatment generates compressive stress on the surface, improving the fatigue resistance. After the improvement of the flat wire body 10, the surface roughness Ra=1.6, and the surface strengthening treatment HV>38, thus resisting the effects of fatigue.

[0077] As shown in Figure 4, according to an embodiment of this disclosure, the wrapping layer 20 includes a base layer 21, which wraps around the outside of the flat wire body 10. The base layer 21 has a coating 211 on it. The base layer 21 can provide protection and facilitates the effective bonding between the coating 211 and the flat wire body 10. The base layer 21 with the coating 211 is used to strengthen the strength of the flat wire body 10. Spraying the coating 211 onto the base layer 21 can achieve excellent conductivity, while improving the strength of the flat wire 100 and reducing stress concentration.

[0078] According to the embodiments of this disclosure, if the thickness of coating 211 is too large, it will affect the conductivity and reduce the adhesion strength; if the thickness of coating 211 is too small, it will reduce the resistance to salt spray, humidity, and low-temperature impact, which is not conducive to improving the strength of the flat wire. Therefore, the thickness of coating 211 can be between 0.006 mm and 0.012 mm, and the thickness of coating 211 can be any value among 0.006 mm, 0.007 mm, 0.008 mm, 0.009 mm, 0.01 mm, 0.011 mm, and 0.012 mm, or any value between any two. The main characteristic of coating 211 is that it is adsorbed on the surface of the underlayer 21 and migrates on the surface of the substrate until it is incorporated into the crystal lattice to form coating 211. Coating 211 is dense and flat, has good adhesion to the substrate, and forms resistance to salt spray, 85°C, 85% humidity, and -40°C low-temperature impact. It ensures adhesion and avoids peeling. The material of coating 211 can be nickel, silver, etc.

[0079] According to an embodiment of the present disclosure, the wrapping layer 20 further includes an insulating layer 22, which wraps around the outside of the base layer 21, thereby providing insulation and facilitating installation into the stator slot.

[0080] According to embodiments of this disclosure, the insulating layer 22 is a high thermal conductivity layer.

[0081] The flat wire 100 is formed from an aluminum alloy forming part at any angle in planar space through a mold, forming an arbitrary spatial structure. A single flat wire body 10 can be installed horizontally, vertically, or at any angle, and multiple flat wire bodies 10 can also be installed horizontally, vertically, or at any angle. Each flat wire body 10 is distributed in several stator slots arranged at intervals along the circumference of the stator core 310, and extends outwards.

[0082] According to the embodiments of this disclosure, the elastic modulus E of the flat wire body 10 is 55Gpa-125Gpa. The optimal relationship between the width ω, thickness δ, and elastic modulus E is determined, which makes the flat wire 100 less stressed under vibration conditions. This is a key technology for balancing mechanical performance and lightweight design. At the same time, the flat design can fill the stator slots more compactly, improve the slot fill factor, thereby improving space utilization, increasing the power density and efficiency of the motor 400, and facilitating the miniaturization design of the motor 400.

[0083] According to embodiments of this disclosure, the flat wire body 10 is made of aluminum, and at least one of silicon, iron, magnesium, boron, copper, manganese, zinc and titanium may be added to form an aluminum alloy that meets the requirements of a lightweight and high-strength design.

[0084] According to embodiments of this disclosure, the yield strength of the flat wire body 10 is ≥65MPa, thereby the flat wire body has a high yield strength.

[0085] According to embodiments of this disclosure, the tensile strength of the flat wire body 10 is ≥110 MPa, thereby the flat wire body has high tensile strength.

[0086] According to an embodiment of the present disclosure, the stator 300 includes a stator core 310 and a flat wire winding 200, which is formed by winding the aforementioned flat wire 100.

[0087] The flat wire winding 200 is composed of flat wires 100 arranged in a certain pattern. In the flat wire winding 200, the flat wires 100 can be distributed in parallel with the same spacing. The flat wires 100 can be extended outward in various combinations, forming a multi-layer three-dimensional spatial layout. The distribution state and size can be adjusted according to the usage conditions. The connection and transition of the flat wires 100, the forming angle, the connection, the plating and coating, the insulation layer 22, and the shielding layer can all have their parameters adjusted according to the usage conditions. This results in a flat wire winding 200 with a compact structure, high space utilization, and more convenient production, use, installation, and disassembly.

[0088] The flat wire winding 100 can be assembled in series or in parallel. The flat wire 100 can be a single layer or multiple layers, and different numbers of connection structures are suitable. At the same time, it can achieve the goal of reducing stress while maintaining strength, while also having a smaller volume and lighter weight.

[0089] The flat wire winding 200 may include multiple winding layers, as shown in Figure 5. Each winding layer contains flat wires 100 composed of multiple flat wires 100 connected end to end within the layer. Each layer includes a first connecting part and a second connecting part arranged in parallel. One end of the first flat wire 100 is connected to the same end of the second flat wire 100. Within the same winding layer, the insertion parts of the first flat wire 100 are respectively arranged in each slot group of the same conductor layer, and the insertion parts of the second flat wire 100 are respectively arranged in each slot group of another conductor layer. Each winding layer contains flat wires 100. The flat wires 100 are connected to an external system through connections. Through extension sections, they can be distributed and extended in various combinations at various angles, in various shapes, and in various directions.

[0090] Multiple flat lines 100 form various types of flat line groups. Each flat line group includes multiple flat lines 100. The flat lines 100 in different flat line groups are connected to achieve the connection between different flat line groups, thereby realizing a three-dimensional layout in space.

[0091] The flat wire winding 200 includes multi-phase windings. For any branch of any phase winding in the flat wire winding 200, the flat wire 100 can be a single conductor or a conductor welded together from multiple flat wires 100. The flat wire 100 includes, but is not limited to, a U-shaped conductor segment.

[0092] As shown in Figure 6, the flat wire winding 200 is formed by winding the flat wire 100 in the stator slot. By using the flat wire 100, the slot fill factor of the flat wire winding 200 can reach more than 70%, which is beneficial to improving the efficiency of the motor 400. The cross-section of the flat wire 100 can be a rectangular, trapezoidal or other flat cross-section, but is not limited to this.

[0093] Furthermore, as shown in Figure 6, each parallel branch of the flat wire winding 200 can be composed of a set of continuous and complete vertical winding coils. The entire motor 400 only requires the lead wires or neutral points to be welded together. The windings have no extra solder joints, which simplifies the complexity of the connection and enables automated production. The use of vertical winding also significantly reduces thermal resistance, improves heat dissipation capacity, and increases the torque density of the motor 400.

[0094] According to the stator 300 of the present disclosure, by adopting the above-mentioned flat wire 100, the vibration intensity of the flat wire 100 is improved, the stress concentration is reduced, the flat wire 100 fills the stator slot more compactly, the slot fill factor is improved, thereby improving the space utilization rate. The stator 300 has a compact overall structure, is easy to install, has high connection efficiency, high space utilization rate, and is more convenient to produce and use.

[0095] The motor 400 according to an embodiment of the present disclosure includes a stator 300 according to an embodiment of the present disclosure.

[0096] Specifically, the motor 400 includes a housing and a stator 300 and a rotor housed within the housing. The rotor and stator 300 are coaxially arranged. The flat wire winding 200 can perform electromagnetic energy conversion and transmission. The rotor includes a rotor core and a shaft. A permanent magnet is disposed on the rotor core. An air gap is left between the stator 300 and the rotor. The motor 400 here can be used as an induction motor 400. However, this disclosure does not specifically limit the application scenario of the motor 400.

[0097] The position and orientation of the flat wire 100 in the motor 400 can be adjusted along with other components. By adjusting the width, thickness and elastic modulus of the flat wire 100, the optimal values ​​are determined through simulation analysis, which improves strength and reduces stress, while making the motor 400 system more integrated and lighter.

[0098] According to the embodiments of the present disclosure, by adopting the stator 300 described above, the vibration intensity of the flat wire 100 can be improved, thereby reducing stress concentration. The flat wire 100 fills the stator slots more compactly, increasing the slot fill factor, thereby improving space utilization, increasing the power density and efficiency of the motor 400, and facilitating the miniaturization design of the motor 400.

[0099] According to an embodiment of the present disclosure, a vehicle 500 includes a body and a motor 400 according to an embodiment of the present disclosure. The motor 400 is located inside the body. By using the motor 400, the stress requirements under vibration conditions can be met, and it has a good strength effect.

[0100] By employing a flat wire design model, the width and quality of flat wire products are significantly improved. This invention improves flow uniformity by designing the shape, thickness, and width of the flat wire, thus solving the extrusion process challenges of large spread ratios and large aspect ratios.

[0101] The present disclosure will be explained below with reference to embodiments. Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be construed as limiting the scope of the disclosure. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in the art or in accordance with the product manual.

[0102] Six flat wire body factor structures were designed using DOE (Design of Experiments) single-factor tuning: 3.3 mm width, 2.6 mm thickness, elastic modulus 74.0 GPa; 3.3 mm width, 6.1 mm thickness, elastic modulus 72.0 GPa; 4.2 mm width, 2.0 mm thickness, elastic modulus 69.9 GPa; 3.3 mm width, 1.0 mm thickness, elastic modulus 68.0 GPa; 3.3 mm width, 25 mm thickness, elastic modulus 69.9 GPa; and 4.2 mm width, 2.0 mm thickness, elastic modulus 35.0 GPa. These are detailed in Examples 1-3 and Comparative Examples 1-3.

[0103] Example 1

[0104] Table 5

[0105]

[0106] Based on the parametric relationship of the flat wire body:

[0107] δ∈{2(1+η) ,6[2(1+η) ]

[0108] {2(1+η)} }={2.2* +0.1 2 *3.3} = 1.12mm

[0109] {6[2(1+η) ]}={6*[2.2* +0.1 2 *3.3]}=6.70mm

[0110] In Example 1, δ∈{1.12mm, 6.70mm}, δ=2.6mm satisfies the relation.

[0111] Example 2

[0112] This embodiment is used to illustrate the flat wire body disclosed in this disclosure, including most of the structure in Embodiment 1, the difference being:

[0113] Table 6

[0114]

[0115] Based on the parametric relationship of the flat wire body:

[0116] {2(1+η)} }={2.2* +0.12 *3.3} = 1.13mm

[0117] {6[2(1+η) ]}={6*[2.2* +0.1 2 *3.3]}=6.79mm

[0118] In Example 2, δ∈{1.13mm, 6.79mm}, δ=6.1mm, which satisfies the relation.

[0119] Example 3

[0120] This embodiment is used to illustrate the flat wire body disclosed in this disclosure, including most of the structure in Embodiment 1, the difference being:

[0121] Table 7

[0122]

[0123] Based on the parametric relationship of the flat wire body:

[0124] {2(1+η)} }={2.2* +0.1 2 *3.3} = 1.64mm

[0125] {6[2(1+η) ]}={6*[2.2* +0.1 2 *3.3]}=9.81mm

[0126] In Example 3, δ∈{1.64mm, 9.81mm}, δ=2mm, which satisfies the relation.

[0127] Comparative Example 1

[0128] This comparative example is used to illustrate the flat wire body disclosed in this disclosure, including most of the structure in Embodiment 1, the difference being:

[0129] Table 8

[0130]

[0131] Based on the parametric relationship of the flat wire body:

[0132] {2(1+η)} }={2.2* +0.1 2 *3.3} = 1.16mm

[0133] {6[2(1+η) ]}={6*[2.2* +0.1 2 *3.3]}=6.98mm

[0134] In Comparative Example 1, δ∈{1.16mm, 6.98mm}, δ=1.0mm, which does not satisfy the relation.

[0135]

[0136] Comparative Example 2

[0137] This comparative example is used to illustrate the flat wire body disclosed in this disclosure, including most of the structure in Embodiment 1, the difference being:

[0138] Table 9

[0139]

[0140] Based on the parametric relationship of the flat wire body:

[0141] {2(1+η)} }={2.2* +0.1 2 *3.3} = 1.15mm

[0142] {6[2(1+η) ]}={6*[2.2* +0.1 2 *3.3]}=6.89mm

[0143] In Comparative Example 2, δ∈{1.15mm,6.89mm}, δ=25mm, which does not satisfy the relation.

[0144]

[0145] Comparative Example 3

[0146] This comparative example is used to illustrate the flat wire body disclosed in this disclosure, including most of the structure in Embodiment 1, the difference being:

[0147] Table 10

[0148]

[0149] Based on the parametric relationship of the flat wire body:

[0150] {2(1+η)} }={2.2* +0.1 2 *3.3} = 2.30mm

[0151] {6[2(1+η) ]}={6*[2.2* +0.1 2 *3.3]}=13.78mm

[0152] In Comparative Example 3, δ∈{2.30mm,13.78mm}, δ=2mm, which does not satisfy the relation.

[0153] Performance testing

[0154] The flat wire body provided above was tested. The test method was to perform vibration for 22 hours with the installation accessories attached; the frequency was in the broadband range of 10-1000 Hz, and the power density was in the range of [0.2-30 [m / s] 2 ) 2 [ / HZ] range, using vibration conditions RMS (Root Mean Square, effective value of vibration velocity) 27.8 m / s 2 The working conditions must be such that there is no mechanical damage or loosening after the test.

[0155] The stress test results of the flat wire body obtained from the test results of Examples 1-3 and Comparative Examples 1-3 are filled in Table 11.

[0156] Table 11

[0157]

[0158] As can be seen from the test results in Table 11, the flat wire bodies obtained by using the relationships defined in Examples 1-3 of this disclosure have a power density of 0.2-30 (m / s²) in the broadband frequency range of 10-1000 Hz. 2 [Hz] range, using vibration conditions RMS (Root Mean Square, effective value of vibration velocity): 27.8 m / s 2 Under normal operating conditions, the stress is low, which can meet the stress requirements of vibration conditions and has a good strength effect.

[0159] Although embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A flat wire for an electric machine, wherein, The flat wire has a width direction and a thickness direction in the direction perpendicular to its extension. The flat wire includes a flat wire body, the dimension of the flat wire body in the thickness direction is δ, the dimension of the flat wire body in the width direction is ω, and the elastic modulus of the flat wire body is E, satisfying: δ∈{2(1+η) ,6[2(1+n) ]｝， Where μ is 0.5, and the unit is Gpa / mm; η is 0.1, and it is a dimensionless quantity; ω is in mm; δ is in mm; and E is in Gpa.

2. The flat wire for a motor according to claim 1, wherein, Along the length direction of the flat wire, the flat wire includes a first connecting segment, a first extension segment, a transition segment, a second extension segment, and a second connecting segment connected in sequence. The first extension segment and the transition segment are connected by radial bending in the width direction of the flat wire, and the second extension segment and the transition segment are connected by radial bending in the thickness direction of the flat wire. There is an angle between the extension lines of the first extension segment and the second extension segment.

3. The flat wire for a motor according to claim 2, wherein, The angle between the first connecting segment and the first extension segment is an obtuse angle; and / or, the angle between the extension line of the first extension segment and the extension line of the second extension segment is an obtuse angle; and / or, the angle between the second connecting segment and the second extension segment is an obtuse angle.

4. The flat wire for a motor according to claim 2, wherein, The first connecting segment and the second connecting segment define a plane, and the angle between the extension lines of the first extension segment and the extension lines of the second extension segment projected onto the plane is θ, satisfying: 90°≤θ≤150°.

5. The flat wire for a motor according to claim 2, wherein, The bending radius of the first extension segment and the transition segment is R1, satisfying: R1≥ω; and / or, the bending radius of the second extension segment and the transition segment is R2, satisfying: R1≥δ.

6. The flat wire for an electric motor according to claim 2, wherein, It also includes a first pin and a second pin, wherein the first pin is located at the end of the first connecting segment away from the first extension segment, and the second pin is located at the end of the second connecting segment away from the second extension segment. The first pin and the second pin are bent away from each other, or the first pin and the second pin are bent to the same side.

7. The flat wire for an electric motor according to any one of claims 1-6, wherein, The flat wire also includes a base layer, which is wrapped around the outside of the flat wire body and has a coating.

8. The flat wire for an electric motor according to claim 7, wherein, The thickness of the coating is between 0.006 mm and 0.012 mm.

9. The flat wire for an electric motor according to claim 7, wherein, The flat wire also includes an insulating layer that wraps around the outside of the underlay.

10. The flat wire for an electric motor according to any one of claims 1-9, wherein, The elastic modulus E of the flat wire body is 55 GPa-125 GPa.

11. The flat wire for an electric motor according to any one of claims 1-10, wherein, The material of the flat wire body includes aluminum and at least one of the following: silicon, iron, magnesium, boron, copper, manganese, zinc and titanium.

12. The flat wire for an electric motor according to any one of claims 1-11, wherein, The yield strength of the flat wire body is ≥65MPa; and / or, the tensile strength of the flat wire body is ≥110MPa.

13. A stator, wherein, The stator includes a stator core and a flat wire winding, wherein the flat wire winding is formed by flat wire winding for motors according to any one of claims 1-12.

14. An electric motor, wherein, Includes the stator according to claim 13.

15. A vehicle, wherein, Includes the motor according to claim 14.

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