Split winding process design and manufacturing method

Abstract

The design and manufacturing method of the split winding is characterized by the separate design of the in-slot winding and the end winding, which breaks away from the constraints of traditional processes. This allows for complete freedom in the manufacturing process of the in-slot winding and the end winding, enabling the use of diverse configurations and processes. It simplifies the process, saves copper materials, and improves performance. Trapezoidal or irregularly shaped slots can be used to maximize the slot fill factor while ensuring magnetic flux density distribution. At the same time, the in-slot and out-of-slot windings can be designed with more layers to improve the skin effect, enhance temperature resistance, reduce the axial dimension of the end winding, and lower costs.

Description

Technical Field

[0001] This invention belongs to the field of electric motor and new energy vehicle design and manufacturing technology. Background Technology

[0002] With the rapid development of the new energy vehicle industry, especially the pure electric vehicle industry, higher requirements have been placed on indicators such as electric power density, efficiency, volume, and cost. Flat wire motors have replaced round wire motors as the mainstream in the new energy vehicle market. In order to improve performance indicators such as efficiency, most main drive motors now use distributed windings. Especially for motors with a small number of pole pairs, the slot pitch of the distributed windings is very large, which greatly increases the length of the end windings, the axial dimension is long, and the process is complicated. The same problem applies to flat wire motors, where the winding forming process is complicated and the cost increases. Summary of the Invention

[0003] This invention addresses the aforementioned problems by proposing a "distributed, separate winding process design and manufacturing method." Its key features include: a separate design for the in-slot winding and the end winding, freeing them from traditional process constraints. This allows for complete freedom in the manufacturing process of both the in-slot and end windings, enabling the use of diverse configurations and processes. This simplifies the manufacturing process, saves copper, and improves performance. Trapezoidal or irregularly shaped slots can be used to maximize slot fill factor while ensuring magnetic flux density distribution. Furthermore, the in-slot and out-of-slot windings can be designed with more layers, improving the skin effect, enhancing temperature resistance, reducing the axial dimension of the end winding, and lowering costs.

[0004] This is referred to as the "double-split winding process". This process is applicable to traditional round wire motors, flat wire motors, and ultra-flat wire motors, and is suitable for radial flux motors and axial flux motors. This application mainly uses ultra-flat wire motors as an example for illustration. For related content on ultra-flat wire motors, please refer to the author's previous applications.

[0005] The dual-slot winding process simplifies the in-slot winding into several mutually insulated straight conductors, greatly simplifying the forming and assembly processes. It also makes it easier to improve slot fill factor, process stability, safety, and yield. The straight conductors can be directly processed from bare copper (or aluminum, etc.) and then insulated. This allows for more diverse slot design, enabling trapezoidal or irregular slots (see below or related applications). It maximizes slot fill factor while ensuring magnetic flux density distribution and allows for the design of more layers in the in-slot winding, improving the skin effect.

[0006] The later insulation process is no longer limited to the current traditional enameled wire insulation process. A variety of insulation processes can be adopted, which makes the selection of materials and processes for insulation coatings or insulation films more flexible. More heat-resistant materials and processes can be selected, resulting in a thinner insulation layer and better temperature resistance. Different insulation processes and insulation layer thicknesses can be adopted according to the different insulation level requirements of different parts of the motor winding, improving the temperature resistance insulation type while improving the slot fill factor. For the end windings, the space compactness can be improved, the axial dimension of the end windings can be reduced, the volume can be reduced, the materials used can be reduced, and the cost can be reduced.

[0007] The aforementioned advantages also apply to end windings. For traditional motors, the main technological challenges lie in the design, processing, and assembly of end windings. However, separating the end windings from the slot windings allows for a significant expansion of the design methods and creative possibilities for end windings, enabling the adoption of diverse structural processes. Due to space limitations, this application only presents one implementation example. For more information on related end winding molding structures, please refer to the relevant technical applications.

[0008] Alternatively, different materials can be used for the in-slot windings and the out-of-slot windings. For example, copper can be used for the in-slot windings, and aluminum for the out-of-slot windings. For large motors, especially those with a small number of poles, this approach can significantly reduce costs, including raw material costs, processing costs, and assembly costs. Note: Because the space outside the slot is unrestricted, a larger aluminum cross-sectional area can be selected to ensure that its resistance does not increase.

[0009] Alternatively, different design methods can be customized according to the characteristics of the motor. For example, if the goal is to maximize the efficiency of the motor, materials with low resistivity can be used for the end windings, and the conductive cross-section can be further increased to minimize the resistance of the end windings. A parallel winding scheme with more layers or strands can be used to minimize both DC and AC losses in the end windings, while also adopting better heat dissipation technology.

[0010] Similarly, if the goal is to reduce costs as much as possible without prioritizing efficiency, low-cost materials with higher resistivity can be used for the end windings. At the same time, the conductive cross-section can be further reduced to decrease the amount of material used, thereby significantly reducing costs.

[0011] Case Analysis: Assumptions: The slot winding uses copper, and the end winding uses aluminum. Even under the premise of maintaining the same end winding resistance, i.e., maintaining the same performance, using aluminum can reduce costs by approximately 8 times. Note: This only refers to the cost reduction ratio when aluminum is used instead of copper for the end winding. Analysis: Although the resistivity of aluminum is greater than that of copper, the density of aluminum is significantly lower than that of copper, and the price of raw materials is also significantly lower than that of copper. Therefore, this solution of replacing copper with aluminum for the end winding while maintaining the same motor performance has strong market potential.

[0012] Similarly, if the goal is to minimize the size of the motor and reduce its axial dimension, a structure with a very flat axial dimension can be used to design the end winding structure. For details, please refer to the relevant application.

[0013] Note: The method of separating the slot windings from the end windings is also applicable to motors with concentrated windings.

[0014] Double-slot ultra-flat wire winding process: Both the slot and the outside of the slot are made of ultra-flat wire, which has ultra-flat subdivision and super high temperature resistance characteristics, reduces skin effect and greatly improves peak power.

[0015] Overview of Distributed Separate Ultra-Flat Wire Motors:

[0016] The distributed split ultra-flat wire motor is a structural innovation based on the existing flat wire motor without changing the main electromagnetic scheme. It has the advantages of zero theoretical risk and high industrial chain inheritance. It can reduce the axial length of the end winding, save copper wire usage, reduce copper loss, reduce yield effect, increase slot fill factor, improve power density and efficiency, reduce motor axial size, improve heat dissipation performance, and reduce process difficulty and cost.

[0017] (Definition and Explanation of Distributed Separate "Dual-System" Ultra-Flat Wire Motor: Under the premise of electromagnetic theory being consistent with conventional distributed winding, the design of the slot winding and the end winding is separated, breaking free from the constraints of traditional processes. This allows for complete freedom in the manufacturing process of the slot winding and the end winding, enabling the use of diverse configurations and processes, saving copper materials, and reducing axial dimensions; Ultra-flat wire: Both the slot and the end winding are made of ultra-flat wire, which has ultra-flat subdivision and super high temperature resistance characteristics, reducing the skin effect and significantly improving peak power.)

[0018] Innovation points:

[0019] 1. By adopting high- and low-order windings or separate winding schemes, the axial dimension of the end windings can be significantly reduced. The dimension of the end windings can be controlled between 4-15 mm depending on the scheme. This reduces the amount of copper wire used, thereby lowering copper losses and raw material costs. The end windings participate in excitation work, transforming ineffective windings into effective windings, which is equivalent to increasing the slot fill factor, significantly reducing copper consumption and copper losses, while also improving the heat dissipation performance of the end windings.

[0020] 2. The separation and modularization of in-slot windings and end windings represents a significant reform of traditional motor wiring processes. This allows both in-slot and end windings to be manufactured independently from the stator assembly, facilitating modularization and standardization. Motors with the same number of slots can be freely combined, and different pole pair numbers can be achieved by selecting different end winding discs. This further standardizes the motor industry chain. Simultaneously, it allows the motor industry to enter a "wireless era," directly using bare material and insulation layers for online synthesis. This eliminates the need for bending and abrasion damage to the insulation layer, and the choice of insulation materials is no longer limited by traditional enameled wire processes, greatly expanding the range of available materials. It allows for the use of high-temperature resistant materials exceeding 300 or even 500 degrees Celsius for insulation, significantly increasing the motor's peak power. Furthermore, the separation design of in-slot and end windings allows for the use of flat wires with different cross-sections inside and outside the slot, achieving trapezoidal flat wire slots, which alone can increase slot fill factor by 27%.

[0021] 3. Separation design of parent layer flat wire and sub-layer flat wire (matrix flat wire), illustrated with the attached example: Using a 72-slot two-layer parent layer trapezoidal slot flat wire configuration can further improve slot fill factor and voltage safety level. Only high-voltage insulation treatment is needed between the two layers of parent flat wire and between the iron core slot walls. The 12 sub-layer flat wires within the same parent layer have a parallel winding zero-voltage characteristic, requiring no high-voltage insulation; only micro-gap isolation is needed. Isolation insulation can be achieved using a process similar to silicon steel sheet coating, micron-level high-temperature resistant film, ceramics, or basalt, etc., to achieve internal cooling and heat exchange, improving heat dissipation characteristics. The sub-layer flat wire can also undergo further matrix flat wire treatment using a process similar to photolithography to further improve the skin effect, achieving micron or even nanometer-level insulation between layers, obtaining an effect equivalent to 24 layers of flat wire. That is: visually, two layers of parent layer flat wire = 24 layers of sub-layer flat wire + 24 * 5 = 120 matrix flat wires, significantly reducing mid-to-high frequency copper losses.

[0022] 4. The independent design of the end windings allows for diverse and flexible end winding process design. Ultra-thin copper sheet structures can be used to achieve cross-phase electrical connections between windings in parallel space, making the current-induced triangular trajectory of each phase end winding a straight trajectory, reducing the current path and resistance. At the same time, the ultra-thin copper sheet structure is beneficial for reducing the skin effect and heat dissipation. Similarly, the ultra-thin copper sheet can also be matrixed using photolithography in the pre-processing stage to further improve the skin effect.

[0023] 5. Further reforms to manufacturing and assembly processes, and the separation design of in-slot windings and end windings, allow current enameled wire source factories to no longer produce enameled wire, but instead to carry out large-scale standardized manufacturing of in-slot windings and end windings. After purchasing, the main engine manufacturer can directly insert the in-slot windings into the stator core slots and embed the end windings into the motor end cover, realizing the integrated manufacturing of end windings and motor end cover. At the same time, a cooling channel for the end windings is reserved in the end cover to achieve an immersion oil cooling or water cooling effect for the end windings, and significantly reduce the axial dimension of the motor.

[0024] The separate assembly of the slot winding and the end winding causes the assembly process of the end winding to lag behind the motor rotor assembly sequence. Therefore, the cross-slot trajectory of the end windings of different phases can be changed from an arc to a straight line, i.e., the arc length becomes the chord length, further saving copper and reducing copper loss. Note: To improve the conductivity of the end winding and the slot winding, a transitional conductive silver film can be added according to the differentiated pricing of high-end and low-end products. That is, a layer of silver film is added to the joint area between the end winding and the slot winding to improve the joint conductivity (as long as the process is rationalized, the conductivity of this pressure joint solution is no less than that of welding, and may even optimize the welding process performance from the perspective of effective conductive area and yield; of course, even if welding is used, the number of solder joints will be reduced by a factor of two, and at least half can be welded outside the slot).

[0025] Therefore, after the process is completed, the slot windings in the stator and the end windings in the end cover can be encapsulated as a whole to further improve insulation safety, thermal conductivity and shock and noise resistance.

[0026] Note: If it is for an axial flux motor, the in-slot and out-of-slot windings can be pre-formed first, and all windings can be integrated into one piece before being inlaid and combined with the iron core.

[0027] 6. The rolling brush electrically excited rotor uses a unique rolling brush instead of the traditional sliding brush, improving lifespan and significantly increasing the conductive area. After long-term verification, this solution has demonstrated high reliability and can meet the requirements of the entire vehicle lifecycle. It is also low-cost and compact, eliminating rare-earth permanent magnet materials, reducing costs while improving safety and raising the rotor's maximum speed limit, which is beneficial for increasing the motor's peak power. Furthermore, it eliminates the risk of permanent magnet demagnetization at high temperatures. Combined with the aforementioned ultra-flat wire's super high-temperature resistance potential, the combined technology allows the motor's instantaneous peak power to exceed 500 degrees Celsius at high temperatures, resulting in a significant increase in peak power. In addition, the electrically excited rotor expands the diversity of motor control strategy parameters, allowing for timely adjustment of the excitation current to extend the motor's high-efficiency range and optimize the motor's overall efficiency and power characteristic curves.

[0028] 7. Composite permanent magnet rotor: High magnetic resistance material is used to fully combine permanent magnets and silicon steel with mortise and tenon joints or casting, so as to completely eliminate magnetic bridges and eliminate the need for carbon fiber winding process, reduce magnetic leakage, reduce costs and eliminate the negative problem of carbon fiber winding occupying air gap space.

[0029] 8. Distributed ultra-flat wire axial flux motor: The manufacturing process is simplified. The slot windings and end windings are produced using a coplanar integrated stamping process, similar to stamping silicon steel sheets. The stamping process combined with an ultra-thin high-temperature resistant insulating coating, along with the separate design of the mother layer flat wire and the daughter layer flat wire (matrix flat wire), offers the same advantages as mentioned above. The end windings can be connected using pressure contact or resistance welding. The core adopts a split-combination expansion connection and positioning process, which reduces the core manufacturing cost of the axial flux motor and forms a bidirectional flux configuration, significantly increasing the power density. At the same time, the bidirectional flux can effectively balance the axial magnetic pull. In addition, the centrifugal force of the rotor core magnets of the axial flux motor is perpendicular to the air gap surface. This allows for the use of a thicker, high-strength centrifugal restraint sleeve to achieve radial mechanical reinforcement of the rotor without affecting the air gap space. This achieves the same effect without the need for carbon fiber technology, reducing costs.

[0030] Definition and Explanation of "Ultra-flat Lines":

[0031] The first layer of meaning: A. Super flatness - The cross-sectional aspect ratio of the copper substrate raw material for ultra-flat wires exceeds 10 times, which reduces the skin effect, improves heat dissipation performance, improves processability, and the inside and outside of the slot are all ultra-thin flat wires, which improves power density and efficiency and reduces costs;

[0032] B-type super high temperature resistant ultra-flat wire has its conductive copper base and insulation layer synthesized online in the later stage. The current type has been developed with an extreme temperature resistance of 290°C, which is much higher than the current temperature resistance limit of 180°C for flat wires. The heat dissipation and thermal conductivity have been further improved, allowing the motor to work at peak power torque for a long time. The overload capacity and power density have been greatly improved.

[0033] The second layer of meaning: It has the commercial connotation of "transcending the traditional flat line", which is a highlight of commercial promotion to attract traffic.

[0034] Recommendation: Redefine the slot winding and end winding. The proposed new names are: Slot conductor bar - copper rod, End conductor plate - copper tile. Strictly speaking, our motor structure is no longer a winding process. The slot winding and end winding are both fixed shapes, which can be fully realized through molded high-frequency stamping or shearing processes. The winding process can be transformed into mechanical stamping and shearing processes, which are easy to achieve molded, standardized, and large-scale production. The traditional enameled wire, enameled flat wire, and motor winding processes will be gone forever. All types of motor specifications can be standardized and serialized, and new industry standards can be established. In the future, the procurement of motor winding components will become as simple and quick as the procurement of standard parts such as screws. Motor windings will enter the era of standard parts procurement and assembly.

[0035] In conclusion:

[0036] Factors that improve power density: 1. Increased slot fill factor and reduced skin effect; 2. Significantly increased upper limit of winding temperature, exceeding 300 to 500 degrees Celsius; 3. Participation of end windings in excitation, resulting in a significant increase in the effective winding ratio; 4. Use of electrically excited rotors or composite permanent magnet rotors, increasing the upper limit of motor speed. These four factors combined can significantly increase the peak power of the motor, potentially exceeding 12, with greater potential for axial flux. The first three factors improve torque, while the fourth improves speed.

[0037] Factors that improve efficiency: 1. Increased slot fill factor and reduced skin effect lead to reduced heat generation and lower copper loss; 2. Improved heat dissipation and thermal conductivity of ultra-flat wires reduce resistance; 3. End windings participate in excitation, significantly increasing the proportion of effective windings, which is equivalent to reducing ineffective copper losses; 4. Using electrically excited rotors or composite permanent magnet rotors increases the upper limit of motor speed, prioritizing high-speed operation over high-current operation to reduce losses; multi-parameter control of electrically excited rotors increases the high-efficiency range, and such rotors can also reduce leakage flux.

[0038] Key factors contributing to cost reduction: 1. Replacing enameled wire with bare copper lowers procurement costs and reduces copper usage; 2. Simplified process flow is more suitable for modular and standardized production, significantly improving production efficiency and reducing defect rate compared to the complex winding process of current flat wire motors; 3. Reduced size, resulting in smaller housing dimensions and lighter raw materials; 4. Replacing permanent magnet rotor with electrically excited rotor eliminates the need for rare-earth permanent magnet materials. Attached Figure Description

[0039] The present invention will now be described in detail with reference to the accompanying drawings and embodiments (taking the "vertical and horizontal circuit board scheme" as an example, see relevant applications for details; the winding example is a double-layer 72-slot winding, see earlier applications for winding relationships):

[0040] Figure 1 Assembly drawing A of a double-wound motor

[0041] Figure 2 Assembly drawing B of a double-wound motor (stator core is hidden).

[0042] Figure 3 Assembly drawing C of a double-wound motor (stator core is hidden).

[0043] Figure 4 Exploded view A of the assembly drawing of a double-wound motor

[0044] Figure 5 Exploded view B of the assembly drawing of a two-part winding motor

[0045] Figure 6 Exploded view of the assembly drawing of a two-part winding motor (C)

[0046] Figure 7 Exploded view of the assembly drawing of a two-part winding motor (D)

[0047] Figure 8 : A star-connected circuit diagram with the upper and lower busbar branches connected in series.

[0048] Figure 9 : A star-connected circuit diagram with parallel branches of the upper and lower busbars

[0049] Figure 10 : A star connection circuit diagram with upper and lower double busbars in series winding relationship (for clarity, only one phase is shown in series winding relationship, that is: the upper and lower busbars in the same slot are first connected in series and then connected in series with the adjacent busbars across slots. The advantage of this scheme is that it can reduce the voltage between the upper and lower busbars in the same slot).

[0050] Figure 11 : A star connection circuit diagram with the upper and lower double-busbar branches having a series connection of lapped windings (for clarity, only one phase is shown with the lapped windings connected in series, while the other two phases are hidden).

[0051] Figure 12-16 Multi-view assembly display diagram of a dual-winding motor Detailed Implementation

[0052] Based on the aforementioned prior applications, this invention proposes a "process design and manufacturing method for a mother-daughter layer circuit that can reduce the skin effect." As shown in the accompanying drawings, each slot contains two layers of windings (case reasoning: a 6-layer, 48-slot dual-branch winding motor is equivalent to a 3-layer, 48-slot single-branch motor, or a 2-layer, 72-slot single-branch motor). This significantly reduces the workload, requiring only high-voltage insulation between the two layers and between the layers and the slot interior. A matrix flat wire structure can be adopted within the same layer (see prior application 202411390722.2). Figure 4(As shown in the case) In order to reduce the skin effect, since the same layer is in parallel and there is zero voltage between them, a similar insulation process to that between silicon steel sheets in motors can be used, with an ultra-thin insulating coating. The thickness of this insulating coating can be at the micrometer level, which can greatly improve the slot fill factor.

[0053] The context can be referenced in the prior application for comparison. The text in this paragraph and the corresponding figure numbers below can be found in the figures of the prior application.

[0054] Regarding 17, the narrow slots on each sub-layer conductor layer shown in the ellipse in 18 are completely open, which is equivalent to multiple parallel conductors in an insulated state that do not contact each other within the same layer. To ensure the stable and non-contact position of the conductors within the same layer, positioning adhesive or potting can be applied to the surface between the layers to solidify and position all conductors. In contrast, 17 retains the area near the end windings on both sides without slots. This scheme shown in 17 is beneficial to increase the integrity and rigidity of the conductors within the same layer. Alternatively, the insulation layer between the sub-layers near the end windings on both sides of all sub-layers within the same parent layer can be removed and welded together to further increase rigidity and pressure contact conductivity. Resistance welding can be used to weld the two ends of all sub-layer conductors within the same parent layer together, or laser welding, electron beam welding, and other processes can be used. Alternatively, materials with better conductivity, such as silver film, can be fused onto the ends of the corresponding contact conductive surfaces of the winding conductors in the slot or the end winding conductors, such as through electroplating silver, to further improve the contact conductivity. Alternatively, an independent silver film gasket can be added between the two pressure contact surfaces.

[0055] 19 and 20: To facilitate clear reading of the drawings, the area indicated by the up and down arrows of part number 19 indicates the geometric dimensions of the upper parent layer; the area indicated by the up and down arrows of part number 20 indicates the geometric dimensions of the lower parent layer.

[0056] Explanation: The upper and lower parent layers are connected in series with a voltage difference, resulting in a high insulation level. To reduce the skin effect, each parent layer is further divided into multiple conductive sub-layers. The conductors in these sub-layers are connected in parallel with zero voltage between them, allowing for the use of very thin insulation solutions. For example, a thin insulating coating, similar to that on silicon steel sheets (0.5-5 micrometers thick), can be used to increase slot fill factor and provide high temperature resistance. Alternatively, high-temperature resistant ceramics or other materials can be used for insulation. These can be discontinuous isolation particles or striped isolation supports, arranged in a thin and discontinuous manner, with conductive interlayer gaps. Cooling liquids or gases can be introduced for direct internal cooling, achieving a highly efficient "internal cooling effect" (see relevant prior applications).

[0057] For details, please refer to the previously submitted application.

[0058] Equivalent Layer Number Comparison Table

[0059]

[0060] For example: The ultra-flat wire has 72 slots, 2 busbars, and 4 sub-layers. Each sub-layer has a narrow slit, which is equivalent to 24 layers of conventional flat wire. This can greatly optimize the skin effect and improve motor efficiency.

[0061] Two-layer analysis shows that the skin effect is actually reduced. The triangular cross-slot W-PIN is stamped as a whole large plane. The same layer can use multiple layers of ultra-thin copper foil + ultra-thin insulating coating. After stacking, it is stamped once. After folding, it becomes two layers. Due to the advantages of the matrix flat wire principle, only two layers of winding are needed, which greatly reduces the difficulty of the process. Even if welding is used, there are very few solder points. Resistance welding can be used, or welding can be done at one time.

[0062] Axial flux is more suitable. Axial flux is also: multiple copper foils + insulating coatings are stacked in the same layer. The whole uses two large layers. A thicker insulating film is used between the two large layers. After the multiple layers are stacked, the edges are pressed and pressure contact conductive or resistance welding is used; one-time pressure resistance welding.

[0063] In summary, almost all models can be constructed with a two-layer structure, or 2 to 3 layers, and a two-layer configuration can be obtained by adjusting the number of slots;

[0064] Furthermore, the same layer uses photolithography, and the insulating film is at the nanoscale.

[0065] The prior application proposes a "triangular arc cross-slot winding process design and manufacturing method," which can achieve better process and cost advantages based on existing technology, and has a more compact volume. Furthermore, it eliminates the need for traditional enameled wire, allowing for direct forming using modern processes such as copper stamping, forging, extrusion, or laser cutting, followed by insulation measures. See the prior application for details.

[0066] Stamping allows for tiny connection points to achieve the desired shape; these are removed after forming by rotating the stamping process using a specific machine.

[0067] Alternatively, a cylindrical copper tube can be made by annular stamping or shearing molds or laser cutting (rotary laser cutting), and then flattened and bent into a circle. In this way, there are no weld points on both sides, and the iron core is a split iron core. There is no problem with axial magnetic flux without a yoke.

[0068] Alternatively, you can use my patented integrated casting and potting system: an opening groove combined with my high magnetic resistance insert with a narrowed opening! The opening groove can also be a separate component!

[0069] Note: The lengths of the inner and outer layers may differ slightly, ensuring that the bent shape forms a standard concentric circle.

[0070] Axial flux motors are more suitable, as the axial flux is exactly the same in each layer; the difference is that bending and folding simultaneously involves arc shaping, resulting in some plastic deformation, which is possible and can be easily achieved through mold shaping or spinning.

[0071] It can also be synthesized by stamping multiple layers of thin copper sheets. During stamping, a high-temperature resistant insulating film is isolated in the middle, which can form a multi-layer relationship, reduce the skin effect, or increase the bevel angle, widen the conductive cross section and increase the number of layers.

[0072] Separate type, end winding; the separate type is advantageous for making the slot winding into trapezoidal flat wire or matrix flat wire; resistance welding efficiency is very high;

[0073] After completion, the motor is impregnated with varnish, potted, or insulated with high-temperature resistant insulation, or simply isolated by air insulation. Then, an electrically excited rotor is added. There is no part that is sensitive to temperature. The higher the temperature, the higher the internal cooling heat exchange efficiency. The motor is insulated, and the entire internal environment is a high-temperature environment with high heat exchange efficiency and high power density! No heat dissipation is required; the thermal energy is converted through insulation, resulting in a secondary heat engine cycle.

[0074] Advantages: Separate design, allowing for the connection of trapezoidal flat wires; the separate design allows for the use of copper rods and plates for both the inside and ends of the groove, resulting in better processability; the inside of the groove can be insulated with high-temperature resistant materials; matrix flat wires can be used, both inside and outside are possible; high temperature resistance; zero defect rate; no need for enameled wire; no need to worry about paint damage during molding; reduced cost; elimination of a series of complex processes; insulation can be added after high-temperature welding, using methods such as varnish impregnation or paper wiping for insulation; can be immersed in coolant, saving more materials; smaller size; butt joint + silver pad or butt joint resistance welding; end size is only 15 mm.

[0075] Welding can be done layer by layer, from the inner layer to the outer layer, with each layer welded and installed, and then welded to the bevel of the joint after the butt joint is joined.

[0076] Advantages of a separate design: A major revolution in the century-old motor manufacturing process; no need for enameled wire; easier rotor assembly; no spatial interference; windings can extend beyond the rotor area; simplified assembly and all processes; no defective products; matrix windings can be used, eliminating the need for multiple layers; improved temperature resistance; and conductivity can be achieved through pressure. Welding is not necessarily better than butt welding; butt welding involves precision machining, while welding may result in incomplete or faulty welds. It offers better maintainability and higher recyclability, representing industry progress! No more damage; even welding is acceptable. Separation allows for diverse processes, even photolithography, zero voltage on the same layer, and nanometer-level insulation.

[0077] To reduce the skin effect and heat dissipation, the thickness and width can be increased, which is the best solution. The process also involves pressing the diagonal seam connecting both sides, folding it in half, bending it into a circle, and then potting and curing it with the end cap. After removing the connecting parts on both sides and processing it into a mirror surface, it can be connected. Alternatively, it can be resistance welded, one-time welded, or high-current welded. Or, the other side can be directly stamped and formed with the winding in the slot in one go, and then welded to the other side, or it can be made into a W-PIN directly.

[0078] This is especially true for axial flux motors, which can be formed by punching the groove and the end in one go and then bending it.

[0079] Axial magnetic flux can be achieved by stamping, stacking, and welding together; or by bending flat wire into a series of circularly wound planar fan shapes, which is the best W-PIN.

[0080] Regarding the aforementioned online applications, especially 202410619722.9; 202410643792.8; 202410684267.0; 202410796145.0; and 202410815412.4, a method can be adopted where subdivided enameled flat wires are pre-assembled into a coarser matrix flat wire group. That is, each original flat wire with a larger cross-section is subdivided into many smaller cross-section micro-flat wire micro-units. After assembly, each micro-unit is densely and compactly combined to improve slot fill factor. These micro-units are then neatly arranged to form a coarse flat wire group. Within the same coarse flat wire group, the micro-units are essentially connected in parallel, similar to the principle of fine enameled wire winding in a circular wire motor, to reduce the skin effect. This structure is simply referred to as a "matrix flat wire winding." See Appendix. Figure 4-5 Among them, part numbers 1 and 3 indicate the outer contour of the matrix flat wire winding; each differential unit of matrix flat wire windings 2 and 4 is insulated from each other; Note: Figure 4 Represents radial flux motor windings. Figure 5 The windings of axial flux motors are described using low-order windings as examples, as detailed in prior applications. Furthermore, since each thick flat wire group is composed of flat wire micro-units, the overall outer contour of the thick flat wire group can be a non-rectangular cross-section. Therefore, the core slot shape can be designed as non-rectangular to further improve the slot fill factor, and can be similar to the core slot shape of a round wire motor.

[0081] The advantages of "matrix flat wire winding" include reducing the skin effect, greatly increasing the flexibility of the winding, making it easier to bend and shape, causing less damage to the wire, allowing for a larger curvature of bending, and forming a very small bending transition arc, which is conducive to further compaction; in addition, the fine flat wires within the same thick flat wire group are connected in parallel, so the voltage between them is zero, so their insulation film can be very thin, further improving the slot fill factor;

[0082] Alternatively, a coarser flat wire can be formed by combining subdivided flat wire gauges.

[0083] It is more conducive to heat dissipation, and a pre-set cooling channel network can fully immerse the micro-flat wire windings in the coolant environment.

[0084] An integral potting, casting, or embedded structure can be adopted to form an integrated module for all end windings, thereby increasing the insulation safety level and mechanical safety, improving insulation and heat dissipation, and reducing electromagnetic noise. Alternatively, prior applications can be consulted.

[0085] The related applications in this series, especially those concerning 202410619722.9; 202410643792.8; 202410684267.0; 202410796145.0; and 202410815412.4, describe structures that are also applicable to split winding designs, such as... Figure 1-3 As shown, where, Figure 1 This represents a single-sided separation, similar to a hairpin flat wire, which is inserted from one side and then joined with the other side; Figure 2 This represents separation on both sides, meaning that the winding in the middle slot is independent, and the windings at both ends are also separate. See: 7.11 Independent forming process and design method for the end windings of the slot windings in axial flux motors; 7.12 Independent forming process for the end windings of the slot windings in motors; 7.15 Separate winding forming process and design method for motors (just applied for, application number not yet received).

[0086] Various welding methods or pressure butt contact electrical connections can be used, or a bare copper plus insulation material solution can be used to improve temperature resistance;

[0087] Note: The previous patent application, "Motor Separate Winding Molding Process and Design Method 7.15 (Just filed, application number not yet received)," is attached. Figure 14-1 All 9 are optimized designs to enhance conductivity; among them, part number 33, with its narrow gap, is designed to reduce the skin effect by subdividing the end winding into several parallel copper plates that are connected in parallel.

[0088] The above solution is applicable to radial flux and axial flux motors;

[0089] All independently separated end windings in the prior application can be pre-formed or independently formed, manufacturing all end windings (including various types such as enameled wire windings and bare copper plate bent plates) into an integrated flat cylindrical end winding module. This module is then installed and mated onto the stator core, just like installing a motor end cover. It ensures that the end windings in the end cover correspond one-to-one with the windings in the slot and that there is a good electrical connection. It also ensures that there are reliable insulation characteristics between them. The electrical connection can be achieved by pressure mating and pressing, or by welding, using processes such as high-current resistance welding, laser welding, electron beam welding, and plasma welding.

[0090] Including the hairpin winding mentioned in the prior application "Independent forming process of end winding of motor slot winding" in 7.12, after the end winding of the existing hairpin winding is separated, it can also be pre-formed or independently formed, and all hairpin type end windings are manufactured into an integrated end winding flat cylindrical module. It is installed and mated to the stator core like installing motor end cover, and it is ensured that the end winding in the end cover corresponds one-to-one with the slot winding and ensures a good electrical connection relationship, and ensures that there are reliable insulation characteristics between them. The electrical connection method can be pressure mating and pressing contact, or welding method can be used, such as high current resistance welding, laser welding, electron beam welding, plasma welding and other processes.

[0091] Alternatively, all winding modules can be encapsulated into a single cylindrical ingot; alternatively, a heat dissipation and cooling labyrinth channel can be pre-designed inside; or insulating ceramic material can be installed on the surface of the copper tile, which can be distributed in a mesh, rod, or granular form. In short, it can isolate and insulate adjacent copper tiles while allowing coolant to enter the gaps between the copper tiles. The copper tile has a large surface area and excellent heat dissipation.

[0092] The side of the integrated end winding module that connects with the slot winding can be precision machined to form a precise flat surface or other curved surface that matches the slot winding, such as a layout annular conical surface, etc. (as shown in the figure). In short, the mating surfaces of the integrated end winding and the slot winding are precision machined, or even paired and precision machined, so that the two can be precisely and accurately mated to achieve good conductivity. They can be mated by pressure contact to conduct electricity, or by welding processes, such as high-current resistance welding, laser welding, electron beam welding, plasma welding, etc.

[0093] Clearly, in this series of solutions, both the end windings and the slot windings can be pre-formed and manufactured. The slot windings can be pre-formed into a single unit before being inserted into the iron core, which can protect the windings and achieve high interlayer density, improving slot fill factor and thermal conductivity. Furthermore, the structure in this application simplifies the slot windings to straight copper rods (commonly known as "copper pillars"), and the end windings to be bent copper plates (commonly known as "copper tiles"). This is no longer a traditional winding made of enameled wire. Similar to the previously applied ultra-flat wire series motors, it allows for the separate design and later synthesis of the conductor layer and insulation layer. This enables the insulation layer to be made of various high-temperature resistant materials, or even air isolation, greatly improving the winding's heat resistance, increasing slot fill factor and winding yield, while reducing process difficulty and cost. See previous applications;

[0094] Ensure that the inductance of each phase is identical to eliminate circulating current.

[0095] The above design method applies to relevant prior applications, especially to patent application schemes 202410619722.9; 202410643792.8; 202410684267.0; 202410796145.0; and 202410815412.4.

[0096] This principle also applies to axial flux motors; counter-rotating dual rotor motors; and internal and external dual flux types.

[0097] Note:

[0098] The part numbering in the attached drawings uses the same numbering for common parts in different drawings, while different numbering is used for related equivalent functional parts in specific drawings. This is entirely to help the instruction manual to more clearly and accurately describe their working principles.

[0099] All design ideas, structures, methods, and theories presented in this document can be used to guide design. The technical content disclosed in its design theories, methods, implementation models, structures, schematic diagrams, structural diagrams, simplified diagrams, mechanism diagrams, and specific embodiments can be used to design and manufacture various types of engine devices. The implementation mechanisms listed in this patent are typical examples; not all specific facility schemes and mechanism types are listed here. Any cross-reorganization, mutual reference, combination, or arrangement of design theories, ideas, methods, models, mechanisms, or components disclosed in this document, as well as various application examples of this technical category, fall within the scope of this intellectual property protection. Any unauthorized use of these principles in design or application constitutes infringement. For example, the relevant design theories and methods are applicable to traditional electric motors, generators, and other similar power sources.

Claims

1. A design and manufacturing method for separate windings, including motor windings, stator, rotor, and housing, characterized by: By separating the slot windings and end windings, the constraints of traditional processes are broken, allowing for complete freedom in the manufacturing process of both the slot windings and end windings. This enables the use of diverse configurations and processes, simplifying the manufacturing process, saving copper materials, and improving performance. Trapezoidal or irregularly shaped slots can be used to maximize the slot fill factor while ensuring magnetic flux density distribution. At the same time, the slot windings can be designed with more layers, improving the skin effect, enhancing temperature resistance, reducing the axial dimension of the end windings, and lowering costs. Abbreviated as "double-split winding process"; this process is applicable to traditional round wire motors, flat wire motors, and ultra-flat wire motors, and is applicable to radial flux motors and axial flux motors. This application mainly uses ultra-flat wire motors as an example for illustration. For related content on ultra-flat wire motors, please also refer to the author's previous applications. The dual-slot winding process simplifies the in-slot winding into several mutually insulated straight conductors, greatly simplifying the forming and assembly processes. It also makes it easier to improve the slot fill factor, process stability, safety, and yield. The straight conductors can be directly processed from bare copper (or aluminum and other conductors) and then insulated. This allows for more diverse core slot design, enabling trapezoidal or irregular slots (see below or related applications). It maximizes the slot fill factor while ensuring magnetic flux density distribution. Additionally, it allows for the design of more layers in the in-slot winding, improving the skin effect. The later insulation process is no longer limited to the current traditional enameled wire insulation process. A variety of insulation processes can be adopted, which makes the selection of materials and processes for insulation coatings or insulation films more flexible. More heat-resistant materials and processes can be selected, resulting in a thinner insulation layer and better temperature resistance. Different insulation processes and insulation layer thicknesses can be adopted according to the different insulation level requirements of different parts of the motor winding, improving the temperature resistance insulation type while improving the slot fill factor. For the end windings, the space compactness can be improved, the axial dimension of the end windings can be reduced, the volume can be reduced, the materials used can be reduced, and the cost can be reduced. The above advantages also apply to end windings. For traditional motors, the main technological difficulty lies in the design, processing, and assembly of end windings. However, the separate design of end windings and slot windings can greatly expand the design methods and thinking space of end windings, and can adopt a variety of structural processes. Due to space limitations, this application only shows one implementation case. For more information on the forming structures of end windings, please refer to the related technical applications. Alternatively, different materials can be used for the in-slot winding and the out-of-slot winding. For example, copper can be used for the in-slot winding and aluminum for the out-of-slot winding. For large motors, especially those with few poles, this approach can significantly reduce costs, including raw material costs, processing costs, and assembly costs. Note: Because the space outside the slot is unrestricted, a larger aluminum cross-sectional area can be selected to ensure that its resistance does not increase. Alternatively, different design methods can be customized according to the characteristics of the motor. For example, if the goal is to maximize the efficiency of the motor, materials with low resistivity can be used for the end windings, and the conductive cross-section can be further increased to reduce the resistance of the end windings as much as possible. In addition, a parallel winding scheme with more layers or strands can be used to minimize both DC and AC losses of the end windings, while better heat dissipation technology can be adopted. Similarly, if the goal is to reduce costs as much as possible without prioritizing efficiency, low-cost materials with higher resistivity can be used for the end windings. At the same time, the conductive cross-section can be further reduced to decrease the amount of material used, thereby significantly reducing costs. Case Analysis: Assumptions: The slot winding uses copper, and the end winding uses aluminum. Even under the premise of maintaining the same end winding resistance, i.e., maintaining the same performance, using aluminum can reduce costs by about 8 times. Note: This only refers to the cost reduction ratio of using aluminum instead of copper for the end winding. Analysis: Although the resistivity of aluminum is greater than that of copper, the density of aluminum is significantly lower than that of copper, and the price of raw materials is also significantly lower than that of copper. Therefore, this solution of replacing copper with aluminum for the end winding under the premise of maintaining the same motor performance has strong market potential. Similarly, if the goal is to minimize the size of the motor and reduce the axial dimension, a structure with a very flat axial dimension can be used to design the end winding structure. For details, please refer to the relevant application. Note: The method of separating the slot windings from the end windings is also applicable to concentrated winding motors. Double-slot ultra-flat wire winding process: Both the slot and the outside of the slot are made of ultra-flat wire, which has ultra-flat subdivision and super high temperature resistance characteristics, reduces skin effect and greatly improves peak power.

2. The design and manufacturing method of the split winding according to claim 1, characterized in that: The above scheme can be referred to as "double-split winding process"; this process is applicable to traditional round wire motors, flat wire motors, and ultra-flat wire motors, and is applicable to radial flux motors and axial flux motors. This application mainly uses ultra-flat wire motors as an example for illustration. For related content on ultra-flat wire motors, please refer to the author's previous applications. Overview of Distributed Separate Ultra-Flat Wire Motors: The distributed split ultra-flat wire motor is a structural innovation based on the existing flat wire motor without changing the main electromagnetic scheme. It has the advantages of zero theoretical risk and high industrial chain inheritance. It can reduce the axial length of the end winding, save copper wire usage, reduce copper loss, reduce yield effect, increase slot fill factor, improve power density and efficiency, reduce motor axial size, improve heat dissipation performance, and reduce process difficulty and cost. (Definition and Explanation of Distributed Separate "Dual-System" Ultra-Flat Wire Motor: Under the premise of electromagnetic theory being consistent with conventional distributed winding, the design of the in-slot winding and the end winding is separated, breaking free from the constraints of traditional processes. This allows for complete freedom in the manufacturing process of the in-slot winding and the end winding, enabling the use of diverse configurations and processes, saving copper materials, and reducing axial dimensions; Ultra-flat wire: Both the in-slot and out-of-slot components are made of ultra-flat wire, featuring ultra-flat subdivision and super high-temperature resistance, reducing the skin effect, and significantly increasing peak power;) Innovation points:

1. By adopting high- and low-order windings or separate winding schemes, the axial dimension of the end windings can be significantly reduced. The end winding dimensions of different schemes can be controlled between 4-15 mm. This reduces the amount of copper wire used, thereby reducing copper losses and raw material costs. The end windings participate in excitation work, turning ineffective windings into effective windings, which is equivalent to increasing the slot fill factor, greatly reducing the amount of copper used and copper losses, while also improving the heat dissipation performance of the end windings.

2. The separation and modularization of in-slot windings and end windings represents a significant reform in traditional motor wiring processes. This allows both in-slot and end windings to be manufactured independently from the stator assembly, facilitating modularization and standardization. Motors with the same number of slots can be freely combined, and different pole pair numbers can be adjusted by selecting different end winding discs. This further standardizes the motor industry chain. Simultaneously, it allows the motor industry to enter a "wireless era," directly using bare material and insulation layer for online synthesis. This eliminates the need for bending and abrasion damage to the insulation layer, and the choice of insulation material is no longer limited by traditional enameled wire processes, greatly expanding the range of available materials. It allows for the use of high-temperature resistant materials exceeding 300 or even 500 degrees Celsius for insulation, significantly increasing the motor's peak power. Furthermore, the separation design of in-slot and end windings allows for the use of flat wires with different cross-sections inside and outside the slot, achieving trapezoidal flat wire slots, which alone can increase slot fill factor by 27%.

3. Separation design of parent layer flat wire and sub-layer flat wire (matrix flat wire), illustrated with the attached example: Adopting a 72-slot two-layer parent layer trapezoidal slot flat wire configuration can further improve slot fill factor and voltage safety level. Only high-voltage insulation treatment is needed between the two layers of parent flat wire and between the iron core slot walls. Within the same parent layer, every 12 sub-layer flat wires are wound in parallel with zero voltage characteristics, requiring no high-voltage insulation; only micro-gap isolation is needed. Isolation insulation can be achieved using a process similar to silicon steel sheet coating, micron-level high-temperature resistant film, ceramics, or basalt, etc., enabling internal cooling and heat exchange from the internal cold airflow, improving heat dissipation characteristics. Within the same sub-layer flat wire, a similar photolithography process can be used for further matrix flat wire treatment, further improving the skin effect and achieving micron or even nanometer-level insulation between layers, achieving an effect equivalent to 24 layers of flat wire. That is: visually, two layers of parent layer flat wire = 24 layers of sub-layer flat wire + 24 * 5 = 120 matrix flat wires, significantly reducing mid-to-high frequency copper losses.

4. The independent design of the end windings allows for diverse and flexible end winding process design. Ultra-thin copper sheet structures can be used to achieve cross-phase electrical connections between windings in parallel space, making the current-induced triangular trajectory of each phase end winding a straight trajectory, reducing the current path and resistance. At the same time, the ultra-thin copper sheet structure helps to reduce the skin effect and heat dissipation. Similarly, the ultra-thin copper sheet can also be matrixed using photolithography in the pre-processing stage to further improve the skin effect.

5. Further reforms to manufacturing and assembly processes, and the separation design of in-slot windings and end windings, allow current enameled wire source factories to no longer produce enameled wire, but instead to carry out large-scale standardized manufacturing of in-slot windings and end windings. After purchasing, the main engine manufacturer can directly insert the in-slot windings into the stator core slots and embed the end windings into the motor end cover, realizing the integrated manufacturing of end windings and motor end cover. At the same time, a cooling channel for the end windings is reserved in the end cover to achieve an immersion oil cooling or water cooling effect for the end windings, and significantly reduce the axial dimension of the motor. The separate assembly of the slot winding and the end winding causes the assembly process of the end winding to lag behind the motor rotor assembly sequence. Therefore, the cross-slot trajectory of the end windings of different phases can be changed from an arc to a straight line, i.e., the arc length becomes the chord length, further saving copper material and reducing copper loss. Note: In order to improve the conductivity of the end winding and the slot winding, a transitional conductive silver film can be added according to the differentiated pricing of high-end and low-end products. That is, a layer of silver film is added to the docking area of ​​the end winding and the slot winding to improve the docking conductivity (as long as the process is rationalized, the conductivity of this pressure docking solution is no less than that of welding, and even the welding process performance can be optimized from the perspective of effective conductive area and yield. Of course, even if welding is used, the number of solder joints will be reduced by a factor of two, and at least half of them can be welded outside the slot). Therefore, after the process is completed, the slot windings in the stator and the end windings in the end cover can be encapsulated as a whole to further improve insulation safety, thermal conductivity and shock and noise resistance. Note: If it is for an axial flux motor, the in-slot and out-of-slot windings can be pre-formed first, and all windings can be integrated into one piece before being inlaid and combined with the iron core.

6. The rolling brush electrically excited rotor uses a unique rolling brush instead of the traditional sliding brush, which improves lifespan and significantly increases the conductive area. After long-term verification, this solution has proven to have high reliability and can meet the requirements of the entire vehicle life cycle. It is also low in cost and compact in size. By eliminating rare earth permanent magnet materials, it reduces costs while improving safety and raising the upper limit of rotor speed, which is conducive to improving the peak power of the motor. In addition, it eliminates the risk of permanent magnet demagnetization at high temperatures. Combined with the super high temperature resistance potential of ultra-flat wire mentioned above, the combination of these two technologies allows the motor's instantaneous peak power to exceed 500 degrees Celsius at high temperatures, resulting in a significant increase in peak power. Furthermore, the electrically excited rotor expands the diversity of motor control strategy parameters, allowing for timely adjustment of the excitation current to extend the motor's high-efficiency range and optimize the motor's overall efficiency and power characteristic curves.

7. Composite permanent magnet rotor: High magnetic resistance material is used to fully combine permanent magnet and silicon steel with mortise and tenon joint or casting joint, so as to completely eliminate the magnetic bridge and eliminate the need for carbon fiber winding process, reduce magnetic leakage, reduce cost and eliminate the negative problem of carbon fiber winding occupying air gap space.

8. Distributed ultra-flat wire axial flux motor: The manufacturing process is simplified. The slot windings and end windings are produced using a coplanar integrated stamping process, similar to stamping silicon steel sheets. The stamping process combined with an ultra-thin high-temperature resistant insulating coating, along with the separate design of the mother layer flat wire and the daughter layer flat wire (matrix flat wire), offers the same advantages as mentioned above. The end windings can be connected using pressure contact or resistance welding. The core adopts a split-combination expansion connection and positioning process, which reduces the core manufacturing cost of the axial flux motor and forms a bidirectional flux configuration, significantly increasing the power density. At the same time, the bidirectional flux can effectively balance the axial magnetic pull. In addition, the centrifugal force of the rotor core magnets of the axial flux motor is perpendicular to the air gap surface. This allows for the use of a thicker, high-strength centrifugal restraint sleeve to achieve radial mechanical reinforcement of the rotor without affecting the air gap space. This achieves the same effect without the need for carbon fiber technology, reducing costs.

3. The design and manufacturing method of the split winding according to claim 1, characterized in that: The meaning of "ultra-flat wire": A. Super flatness - The cross-sectional aspect ratio of the copper substrate raw material for ultra-flat wire exceeds 10 times, which reduces the skin effect, improves heat dissipation performance, improves processability, and the inside and outside of the slot are both ultra-thin flat wires, which improves power density and efficiency and reduces costs; B Super High Temperature Resistance - The conductive copper base and insulation layer of the ultra-flat wire are synthesized online in the later stage. The current type has been developed with an extreme temperature resistance of 290°C, which is much higher than the current temperature resistance limit of 180°C for flat wires. The heat dissipation and thermal conductivity are further improved, allowing the motor to work at peak power torque for a long time. The overload capacity and power density are greatly improved. Recommendation: Redefine the slot winding and end winding. The proposed new names are: slot guide bar - copper rod, end guide plate - copper tile. Strictly speaking, our motor structure is no longer a winding process. The slot winding and end winding are both fixed shapes, which can be formed by high-frequency stamping or shearing processes using molds. The winding process can be transformed into mechanical stamping and shearing processes, which are easy to achieve mold-based, standardized, and large-scale production. The traditional enameled wire, enameled flat wire, and motor winding processes will be gone forever. All types of motor specifications can be standardized and serialized, and new industry standards can be formulated. In the future, the procurement of motor winding components will become as simple and quick as the procurement of standard parts such as screws. Motor windings will enter the era of standard parts procurement and assembly. In conclusion: Factors that improve power density:

1. Increased slot fill factor and reduced skin effect; 2. Significantly increased upper limit of winding temperature, exceeding 300 to 500 degrees Celsius; 3. Participation of end windings in excitation, resulting in a significant increase in the effective winding ratio; 4. Use of electrically excited rotors or composite permanent magnet rotors, increasing the upper limit of motor speed. These four factors combined can significantly increase the peak power of the motor, potentially exceeding 12, with greater potential for axial flux. The first three factors improve torque, while the fourth improves speed. Factors that improve efficiency:

1. Increased slot fill factor, reduced skin effect, reduced heat generation, and lower copper consumption; 2. The heat dissipation and thermal conductivity of ultra-flat wires are improved, and the resistance is reduced; 3. The end windings participate in excitation, which greatly increases the proportion of effective windings, which is equivalent to reducing ineffective copper losses; 4. The use of electrically excited rotors or composite permanent magnet rotors increases the upper limit of motor speed, and prioritizes high speed to replace high current conditions to reduce losses; the multi-parameter control of electrically excited rotors increases the high-efficiency range, and such rotors can also reduce leakage flux. The main factors contributing to cost reduction are:

1. Replacing enameled wire with bare copper reduces procurement costs and the amount of copper used is reduced; 2. The process is simplified and more suitable for modular and standardized production. Compared with the current complex winding process for flat wire motors, production efficiency is greatly improved and the defect rate is reduced.

3. The size is reduced, and the size of the box and the weight of the raw materials are also reduced accordingly; 4. An electrically excited rotor is used instead of a permanent magnet rotor, eliminating the need for rare earth permanent magnet materials; Figure 1: Assembly drawing A of a double-wound motor Figure 2: Assembly drawing B of a double-wound motor (stator core is hidden). Figure 3: Assembly drawing C of a double-wound motor (stator core is hidden). Figure 4: Exploded view of the assembly drawing A of a double-wound motor Figure 5: Exploded view of the assembly drawing of a two-part winding motor (B) Figure 6: Exploded view of the assembly drawing of a two-part winding motor (C) Figure 7: Exploded view of the assembly drawing of a two-part winding motor (D) Figure 8: Star connection circuit diagram with upper and lower double-branch branches in series. Figure 9: Star connection circuit diagram with parallel branches of the upper and lower double busbars. Figure 10: Star connection circuit diagram with upper and lower double busbar branches in series lapped winding relationship (for clarity, only one phase is shown in series lapped winding relationship, that is: the lapped windings in the same slot are first connected in series and then connected in series with the adjacent lapped windings across slots. The advantage of this scheme is that it can reduce the voltage between the upper and lower busbars in the same slot). Figure 11: Star connection circuit diagram with lapped windings in series for the upper and lower double-busbar branches (for clarity, only one phase is shown with lapped windings in series, the other two phases are hidden). Figure 12-16: Multi-view assembly display diagram of a dual-winding motor Based on the aforementioned prior applications, this invention proposes a "process design and manufacturing method for a mother-daughter layer circuit that can reduce the skin effect." As shown in the accompanying drawings, each slot contains two layers of windings (case reasoning: based on a 6-layer 48-slot dual-branch winding motor, it can be equivalent to a 3-layer 48-slot single-branch motor, or a 2-layer 72-slot single-branch motor). This can greatly reduce the workload of the process. Only high-voltage insulation treatment is required between the two layers and between the layers and the slot interior. A matrix flat wire structure can be adopted within the same layer (see the case shown in Figure 4 of prior application 202411390722.2) to reduce the skin effect. Because the layers are connected in parallel and have zero voltage between them, an insulation process similar to that between silicon steel sheet laminations in motors can be used. An ultra-thin insulating coating can be used, with the thickness of the insulating coating at the micrometer level, which can greatly improve the slot fill factor. The context can be referenced in the prior application for comparison. The text in this paragraph and the corresponding figure numbers below can be found in the figures of the prior application. Regarding 17, the narrow slots on each sub-layer conductor layer shown in the elliptical frame 18 are completely open, which is equivalent to multiple parallel conductors in an insulated state that do not contact each other within the same layer. To ensure the stable and non-contact position of the conductors within the same layer, positioning adhesive or potting can be applied to the surface between the layers to cure and position all conductors. In contrast, 17 retains the area near the end windings on both sides without slots. This scheme shown in 17 is beneficial to increase the integrity and rigidity of the conductors within the same layer. Alternatively, the insulation layer between the sub-layers near the end windings on both sides of all sub-layers within the same parent layer can be removed and welded together to further increase rigidity and pressure contact conductivity. Resistance welding can be used to weld the two ends of all sub-layer conductors within the same parent layer together, or laser, electron beam welding, and other processes can be used. Alternatively, materials with better conductivity, such as silver film, can be fused onto the ends of the corresponding contact conductive surfaces of the winding conductors in the slot or the end winding conductors, such as through electroplating, to further improve the contact conductivity. Alternatively, an independent silver film gasket can be added between the two pressure contact surfaces. 19 and 20: To facilitate clear reading of the drawings, the area indicated by the up and down arrows of part number 19 indicates the geometric dimensions of the upper parent layer; the area indicated by the up and down arrows of part number 20 indicates the geometric dimensions of the lower parent layer. Explanation: The upper and lower parent layers are connected in series with a voltage difference, resulting in a high insulation level. To reduce the skin effect, each parent layer is further divided into multiple conductive sub-layers. The conductors in these sub-layers are connected in parallel with zero voltage between them, allowing for the use of very thin insulation solutions. For example, a thin insulating coating, similar to that on silicon steel sheets (0.5-5 micrometers thick), can be used to increase slot fill factor and provide high temperature resistance. Alternatively, high-temperature resistant ceramics or other materials can be used for insulation. These can be discontinuous isolation particles or striped isolation supports, arranged in a thin and discontinuous manner, with conductive interlayer gaps. Cooling liquids or gases can be introduced for direct internal cooling, achieving a highly efficient "internal cooling effect" (see relevant prior applications). Equivalent Layer Number Comparison Table For example: The ultra-flat wire has 72 slots, 2 busbars, and 4 sub-layers. Each sub-layer has a narrow slit, which is equivalent to 24 layers of conventional flat wire. This can greatly optimize the skin effect and improve motor efficiency. Two-layer analysis shows that the skin effect is actually reduced. The triangular cross-slot W-PIN is stamped as a whole large plane. The same layer can use multiple layers of ultra-thin copper foil + ultra-thin insulating coating. After stacking, it is stamped once. After folding, it becomes two layers. Due to the advantages of the matrix flat wire principle, only two layers of winding are needed, which greatly reduces the difficulty of the process. Even if welding is used, there are very few solder points. Resistance welding can be used, or welding can be done at one time. Axial flux is more suitable. Axial flux is also: multiple copper foils + insulating coatings are stacked in the same layer. The whole is only two large layers. A thicker insulating film is used between the two large layers. After the multiple layers are stacked, the edges are pressed and pressure contact conductivity or resistance welding is used; one-time pressure resistance welding. In summary, almost all models can be constructed with a two-layer structure, or 2 to 3 layers, and a two-layer configuration can be obtained by adjusting the number of slots; Furthermore, the same layer uses photolithography, and the insulating film is at the nanoscale. The prior application proposes a "triangular arc cross-slot winding process design and manufacturing method," which can achieve better process and cost advantages based on existing technology, and has a more compact volume. Furthermore, it eliminates the need for traditional enameled wire, allowing for direct forming using modern processes such as copper stamping, forging, extrusion, or laser cutting, followed by insulation measures. See the prior application for details. Stamping allows for tiny connection points to achieve the desired shape; these are removed after forming by rotating the stamping process using a specific machine. Alternatively, a cylindrical copper tube can be made by annular stamping or shearing molds or laser cutting (rotary laser cutting), and then flattened and bent into a circle. In this way, there are no weld points on both sides, and the iron core is a split iron core. There is no problem with axial magnetic flux without a yoke. Alternatively, you can use my patented integrated casting and potting system: an opening groove combined with my high magnetic resistance insert with a narrowed opening! The opening groove can also be a separate component! Note: The lengths of the inner and outer layers may differ slightly, ensuring that the bent shape forms a standard concentric circle. Axial flux motors are more suitable, as the axial flux is exactly the same in each layer; the difference is that bending and folding simultaneously involves arc shaping, resulting in some plastic deformation, which is possible and can be easily achieved through mold shaping or spinning. It can also be synthesized by stamping multiple layers of thin copper sheets. During stamping, a high-temperature resistant insulating film is isolated in the middle, which can form a multi-layer relationship, reduce the skin effect, or increase the bevel angle, widen the conductive cross section and increase the number of layers. Separate type, end winding; the separate type is advantageous for making the slot winding into trapezoidal flat wire or matrix flat wire; resistance welding efficiency is very high; After completion, the motor is impregnated with varnish, potted, or insulated with high-temperature resistant insulation, or simply isolated by air insulation. Then, an electrically excited rotor is added. There is no part that is sensitive to temperature. The higher the temperature, the higher the internal cooling heat exchange efficiency. The motor is insulated, and the entire internal environment is a high-temperature environment with high heat exchange efficiency and high power density! No heat dissipation is required; the thermal energy is converted through insulation, resulting in a secondary heat engine cycle. Advantages: Separate design, allowing for the connection of trapezoidal flat wires; the separate design allows for the use of copper rods and plates for both the inside and ends of the groove, resulting in better processability; the inside of the groove can be insulated with high-temperature resistant materials; matrix flat wires can be used, both inside and outside are possible; high temperature resistance; zero defect rate; no need for enameled wire; no need to worry about paint damage during molding; reduced cost; elimination of a series of complex processes; insulation can be added after high-temperature welding, using methods such as varnish impregnation or paper wiping for insulation; can be immersed in coolant, saving more materials; smaller size; butt joint + silver pad or butt joint resistance welding; end size is only 15 mm. Welding can be done layer by layer, from the inner layer to the outer layer, welding one layer and installing one layer, and then welding along the bevel of the joint after butt joint. Advantages of a separate design: A major revolution in the century-old motor manufacturing process; no need for enameled wire; easier rotor assembly; no spatial interference; windings can extend beyond the rotor area; simplified assembly and all processes; no defective products; matrix windings can be used, eliminating the need for multiple layers; improved temperature resistance; and conductivity can be achieved through pressure. Welding is not necessarily better than butt welding; butt welding involves precision machining, while welding may result in incomplete or faulty welds. It offers better maintainability and higher recyclability, representing industry progress! No more damage; even welding is acceptable. Separation allows for diverse processes, even photolithography, zero voltage on the same layer, and nanometer-level insulation. To reduce the skin effect and heat dissipation, the thickness and width can be increased, which is the best solution. The process also involves pressing the diagonal seam connecting both sides, folding it in half, bending it into a circle, and then potting and curing it with the end cap. After removing the connecting parts on both sides and processing it into a mirror surface, it can be connected. Alternatively, it can be resistance welded, one-time welded, or high-current welded. Or, the other side can be directly stamped and formed with the winding in the slot in one go, and then welded to the other side, or it can be made into a W-PIN directly. This is especially true for axial flux motors, which can be formed by punching the groove and the end in one go and then bending it. Axial magnetic flux can be achieved by stamping, stacking, and welding the sheets together; or by bending flat wire into a series of circularly wound planar fan shapes, which is the best W-PIN. Regarding the aforementioned online applications, especially 202410619722.9; 202410643792.8; 202410684267.0; 202410796145.0; and 202410815412.4, a method can be adopted where subdivided enameled flat wires are pre-assembled into a coarser matrix flat wire group. That is, each original flat wire with a larger cross-section is subdivided into many smaller cross-section micro-flat wire micro-units. After assembly, each micro-unit is densely and compactly combined to improve slot fill factor. After neat arrangement, they form a coarse flat wire group. Within the same coarse flat wire group, the micro-units are essentially electrically connected in parallel, similar to... The principle of parallel winding of fine enameled wire in a round wire motor reduces the skin effect. This structure is simply referred to as a "matrix flat wire winding," as shown in Figures 4-5. Part numbers 1 and 3 indicate the outer contour of the matrix flat wire winding; parts 2 and 4 are each differential unit of the matrix flat wire winding, which is insulated from each other. Note: Figure 4 represents a radial flux motor winding, and Figure 5 represents an axial flux motor winding; both are described using low-order windings as examples, and can be found in prior applications. Furthermore, since each thick flat wire group is composed of flat wire micro-units, the overall outer contour shape of the thick flat wire group can be a non-rectangular cross-section. Therefore, the core slot shape can be designed as non-rectangular to further improve the slot fill factor, and can be similar to the core slot shape of a round wire motor. The advantages of "matrix flat wire winding" include reducing the skin effect, greatly increasing the flexibility of the winding, making it easier to bend and shape, causing less damage to the wire, allowing for a larger curvature of bending, and forming a very small bending transition arc, which is conducive to further compaction; in addition, the fine flat wires within the same thick flat wire group are connected in parallel, so the voltage between them is zero, so their insulation film can be very thin, further improving the slot fill factor; Alternatively, a coarser flat wire can be formed by combining subdivided flat wire gauges. It is more conducive to heat dissipation, and a pre-set cooling channel network can fully immerse the micro-flat wire windings in the coolant environment. An integral potting, casting, or embedded structure can be adopted to form an integrated module for all end windings, thereby increasing the insulation safety level and mechanical safety, improving insulation and heat dissipation, and reducing electromagnetic noise. Alternatively, prior applications can be consulted. The related applications in this series, especially those concerning 202410619722.9; 202410643792.8; 202410684267.0; 202410796145.0; and 202410815412.4, describe structures that are also applicable to split winding designs, as shown in Figures 1-3. Figure 1 represents single-sided splitting, similar to a hairpin flat wire, inserted from one side and then joined to the other side. Figure 2 represents two-sided splitting, i.e., the winding in the middle slot is independent, and the windings at both ends are also separate. See: 7.11 Independent forming process and design method for end windings in slots of axial flux motors; 7.12 Independent forming process for end windings in slots of motors; 7.15 Split winding forming process and design method for motors (newly applied, application number not yet received). Various welding methods or pressure butt contact electrical connections can be used, or a bare copper plus insulation material solution can be used to improve temperature resistance; Note: Figures 14-19 of the previous patent application "Motor Separate Winding Molding Process and Design Method 7.15 (Just filed, application number not yet received)" are all optimized designs to enhance conductivity; among them, part number 33 narrow gap is to reduce skin effect, subdividing the end winding into several parallel copper plates connected in parallel.

4. The design and manufacturing method of the split winding according to claim 1, characterized in that: The above solution is applicable to radial flux and axial flux motors; All independently separated end windings applied for earlier can be pre-formed or independently formed, manufacturing all end windings (including various types such as enameled wire windings, bare copper plate bending plates, etc.) into an integrated flat cylindrical end winding module, which is installed and mated onto the stator core like installing motor end covers, ensuring that the end windings in the end cover correspond one-to-one with the windings in the slot and ensuring a good electrical connection, and ensuring reliable insulation characteristics between them. The electrical connection can be achieved by pressure mating and pressing contact, or by welding, such as high current resistance welding, laser welding, electron beam welding, plasma welding, etc. Including the hairpin winding mentioned in the prior application "Independent forming process of end winding of motor slot winding" in 7.12, after the end winding of the existing hairpin winding is separated, it can also be pre-formed or independently formed, and all hairpin type end windings are manufactured into an integrated end winding flat cylindrical module. It is installed and mated to the stator core like installing motor end cover, and it is ensured that the end winding in the end cover corresponds one-to-one with the slot winding and ensures a good electrical connection relationship, and ensures that there are reliable insulation characteristics between them. The electrical connection method can be pressure mating and pressing contact, or welding method can be used, such as high current resistance welding, laser welding, electron beam welding, plasma welding and other processes. Alternatively, all winding modules can be encapsulated into a single cylindrical ingot; alternatively, a heat dissipation and cooling labyrinth channel can be pre-designed inside; or insulating ceramic material can be installed on the surface of the copper tile, which can be distributed in a mesh, rod, or granular form. In short, it can isolate and insulate adjacent copper tiles while allowing coolant to enter the gaps between the copper tiles. The copper tile has a large surface area and excellent heat dissipation. The side of the integrated end winding module that connects with the slot winding can be precision machined to form a precise flat surface or other curved surfaces that match the slot winding, such as a layout annular cone surface, etc. (as shown in the figure). In short, the mating surfaces of the integrated end winding and the slot winding are precision machined, or even paired and precision machined, so that the two can be precisely and accurately mated to achieve good conductivity. They can be mated by pressure contact to conduct electricity, or by welding processes, such as high-current resistance welding, laser welding, electron beam welding, plasma welding, etc. Clearly, in this series of solutions, both the end windings and the slot windings can be pre-formed and manufactured in advance. The slot windings can be pre-formed into an integral unit before being inserted into the iron core, which can protect the windings and achieve high interlayer density, improving slot fill factor and thermal conductivity. Furthermore, the structure in this application simplifies the slot windings to straight copper rods (commonly known as "copper pillars") and the end windings to bent copper plates (commonly known as "copper tiles"). This is no longer a winding made of enameled wire in the traditional sense. Similar to the ultra-flat wire series motors in the prior application, it allows for the separate design and later synthesis of the conductor layer and insulation layer. This enables the insulation layer to be made of various high-temperature resistant materials, or even air isolation, which greatly improves the heat resistance of the windings, increases the slot fill factor and winding yield, and reduces the process difficulty and cost. See the prior application. Ensure that the inductance of each phase is identical to eliminate circulating current. The above design method applies to relevant prior applications, especially to patent application schemes 202410619722.9; 202410643792.8; 202410684267.0; 202410796145.0; and 202410815412.

4. This principle also applies to axial flux motors; counter-rotating dual rotor motors; and internal and external dual flux types.

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