Flat wire coil and motor

Abstract

The application provides a flat wire coil and a motor, and relates to the technical field of flat wire coils. The flat wire coil comprises multiple layers of windings and a wire changing layer. Each layer of winding is wound by a flat wire along the long side of the cross section of the flat wire, which is parallel to the axis direction around the coil. The wire changing layer is arranged between two adjacent layers of windings, and is used for electrical connection between the two adjacent layers of windings. The application improves the flexibility of winding connection, avoids material tearing, improves space utilization, and facilitates maintenance and adjustment.

Description

Technical Field

[0001] This application relates to the field of flat wire coil technology, and more particularly to a flat wire coil and a motor. Background Technology

[0002] Traditional flat copper wire coils are widely used in transformers, inductors, and axial flux motors. Current technology commonly employs a flat winding process, where the long side of the flat wire cross-section is wound perpendicular to the axis around which the coil is wound. This winding method has significant limitations: firstly, due to the limited processing capacity of the winding machine, when using thin flat wire to make small-sized coils, material tearing easily occurs at the rounded corners, severely affecting product quality; secondly, the flat winding method has low space utilization within the stator slots of the axial flux motor, resulting in a limited number of winding turns that can be accommodated, directly impacting motor performance. Utility Model Content

[0003] The main purpose of this invention is to provide a flat wire coil, which aims to achieve reliable winding of small-sized thin flat wire.

[0004] To achieve the above objectives, this utility model provides a flat wire coil, the flat wire coil comprising:

[0005] Multi-layer winding, each layer of winding is made of flat wire wound along the long side of the cross-section of the flat wire parallel to the axis around which the coil is wrapped;

[0006] A switching layer is disposed between two adjacent winding layers, and the switching layer provides electrical connection between the two adjacent winding layers.

[0007] Optionally, the multilayer winding has a first-layer winding and a last-layer winding;

[0008] The first layer winding is provided with a first lead wire, and the last layer winding is provided with a second lead wire. The first lead wire and the second lead wire are used to connect to external circuits respectively.

[0009] Optionally, the multi-layer winding has two layers, and the first layer winding extends counterclockwise from the first lead wire from the outer ring to the inner ring to the first connecting section of the switching layer.

[0010] Optionally, the last layer winding extends counterclockwise from the inner ring to the outer ring from the second connecting section of the switching layer to the second lead wire.

[0011] Optionally, the switching layer is located at the inner ring position of the first winding and the last winding.

[0012] Optionally, the switching layer includes a first connecting segment, a bending segment, and a second connecting segment. The first connecting segment and the second connecting segment respectively connect two adjacent windings. The bending segment is used to form a transition region winding for connecting the first connecting segment and the second connecting segment.

[0013] Optionally, the diameter of the flat wire is 3 mm.

[0014] Optionally, the thickness of the flat wire is 0.2 mm.

[0015] Optionally, each layer of the winding includes multiple turns of flat wire, with a self-adhesive coating between adjacent turns of flat wire to allow the adjacent turns of flat wire to be adhered and fixed to each other.

[0016] In addition, to achieve the above objectives, this utility model also provides an electric motor, which includes the flat wire coil as described above.

[0017] This utility model embodiment sets up a multi-layer winding, in which each layer of the multi-layer winding is wound with flat wire along the long side of the cross-section of the flat wire parallel to the axis around which the coil is wrapped, and a switching layer is set between adjacent layers of winding to realize the electrical connection between adjacent layers of winding, thereby improving the flexibility of winding connection, and has the advantages of avoiding material tearing, improving space utilization and facilitating maintenance and adjustment. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a flat wire coil according to an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of a flat wire coil according to another embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the structure of a flat wire coil according to another embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the structure of a flat wire coil according to another embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the structure of a flat wire coil according to another embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of the structure of a flat wire coil according to another embodiment of the present invention;

[0026] Figure 7 This is a schematic diagram of the structure of a flat wire coil in the prior art.

[0027] Explanation of icon numbers:

[0028]

[0029] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Well-known modules, units, and their connections, links, communications, or operations are not shown or described in detail. Furthermore, the described features, architectures, or functions can be combined in any way in one or more embodiments. Those skilled in the art should understand that the various embodiments described below are only for illustrative purposes and are not intended to limit the scope of protection of the present invention.

[0031] Traditional flat copper wire coils are widely used in transformers, inductors, and axial flux motors. Current technology commonly employs a flat winding process, where the long side of the flat wire cross-section is wound perpendicular to the axis around which the coil is wound. This winding method has significant limitations: firstly, due to the limited processing capacity of the winding machine, when using thinner flat wire to make small-sized coils, material tearing easily occurs at the rounded corners, severely affecting product quality; secondly, the flat winding method has low space utilization within the stator slots of axial flux motors, resulting in a limited number of winding turns, directly impacting motor performance. Although round wire can be used to wind smaller coils, its slot fill factor is low, failing to meet the requirements of high-performance motors. Furthermore, existing integrated winding processes directly wind the coil onto the stator core. This structure not only lacks flexibility, making it difficult to adjust winding performance according to different needs, but also presents significant inconvenience during maintenance.

[0032] The main solution of this application embodiment is: by setting up a multi-layer winding, each layer of the multi-layer winding is wound with flat wire along the long side of the cross-section of the flat wire parallel to the axis around which the coil is wrapped, and then setting a switching layer between adjacent layers of winding to realize the electrical connection between adjacent layers of winding.

[0033] This application provides a solution that improves the flexibility of winding connections, with advantages such as avoiding material tearing, increasing space utilization, and facilitating maintenance and adjustment.

[0034] In the existing technology, please refer to Figure 7 As shown, flat copper wire coils generally employ a flat winding process, with the long side of the flat wire cross-section perpendicular to the coil axis. This winding method makes the thin flat wire prone to tearing at the rounded corners, limiting the application of small-sized coils. Flat-wound coils can accommodate fewer turns within the axial flux stator slots, making it difficult to meet high slot fill factor requirements. For motor applications requiring compact design and high efficiency, traditional winding methods suffer from bottlenecks such as limited coil size and low copper wire utilization.

[0035] The root cause of this problem lies in the fundamental contradiction between the mechanical strength requirements of flat wire in the flat winding process and the need for miniaturization. Analysis of the stress state of the flat wire reveals that when the long side of the flat wire is parallel to the axis, the stress distribution of the material during winding is more uniform. Considering the layered structure of the coil, a transition region is proposed between adjacent winding layers to achieve electrical connection, thereby increasing the effective number of turns within a limited space.

[0036] Based on the above, referring to Figure 1 In one embodiment of this utility model, the flat wire coil includes a multi-layer winding 10 and a switching layer 20, wherein:

[0037] Each layer of winding 10 is made of flat wire wound along the long side of the cross-section of the flat wire parallel to the axis around which the coil is wrapped; the switching layer 20 is disposed between two adjacent layers of winding 10, and the switching layer 20 provides electrical connection between the two adjacent layers of winding 10.

[0038] Among them, the multi-layer winding 10 refers to a conductive structure stacked along the axial direction. Each layer of winding 10 is formed by arranging flat wires with their long sides parallel to the axis, which can be achieved using a continuous winding process. This arrangement reduces stress concentration at the edges of the flat wires during winding. The transition layer 20 refers to the transition region located between adjacent winding layers 10, which can be achieved using a bending forming process. This region physically connects the conductive paths of adjacent windings 10 through a specific geometry, ensuring the continuity of current conduction between layers.

[0039] In this design, the long side of the flat wire is kept parallel to the axis during winding, ensuring that the wire primarily undergoes deformation in the width direction rather than bending in the thickness direction during bending. Adjacent winding layers (10 layers) are electrically connected via a switching layer (20), which is spatially located at the junction of two winding layers (10 layers) and forms a smooth transition through a bend at a specific angle. This structure allows for the arrangement of more winding layers (10 layers) within the same axial height and avoids the vulnerability of thin flat wires to breakage in traditional flat winding processes.

[0040] Each layer of the winding includes multiple turns of flat wire, with a self-adhesive coating between adjacent turns of flat wire to allow the adjacent turns of flat wire to be adhered and fixed to each other.

[0041] Self-adhesive coatings can be thermosetting or photocuring adhesives that provide sufficient adhesion during or after winding to ensure the stability and reliability of the flat wire coil structure. The use of self-adhesive coatings allows the wound finished products to adhere to each other, thus maintaining specific dimensions and shapes.

[0042] This embodiment proposes a flat wire coil using a vertical winding process (i.e., the long side of the flat wire cross-section is parallel to the axis of the coil), making it possible to wind small-sized coils with small-sized flat wire. Furthermore, the coil is wound in two layers, allowing for more copper wire to be placed within the same slot size.

[0043] The small-sized flat wire coil proposed in this embodiment adopts a vertical winding method, that is, the long side of the flat wire cross-section is parallel to the axis of the coil winding. In this way, even small-sized thin flat wires can be wound using the coil core winding method. At the same time, the coil is wound in two layers, which can accommodate more turns and is beneficial to improving motor performance.

[0044] In this embodiment, the flat wire can be 0.2mm thick and 3mm wide. During winding, start from the upper end of the upper layer and wind counterclockwise from the inside of the outer mesh. After a certain number of turns, wind to the innermost layer 20 and then jump to the first layer. Then continue to wind counterclockwise from the inside to the outside to a certain number of turns before being led out from the lower end of the lower layer.

[0045] In addition, compared with other integrally wound motor coils (i.e., directly wound on the stator core), this separately wound coil is more flexible in application, and can be made into a variety of windings 10 with different performance according to needs, and is more convenient to maintain.

[0046] Compared to existing technologies, traditional flat-wound coils have their long sides perpendicular to the axis, resulting in significant bending stress in the thickness direction of the wire during winding. This embodiment, however, significantly reduces material stress by changing the arrangement direction of the flat wires. Existing technologies employ single-layer winding or integral molding structures, while this embodiment achieves a multiplier effect in the number of turns while maintaining structural compactness through layered winding combined with a wire replacement layer 20 design.

[0047] Through the above technical solution, this embodiment effectively solves the material breakage problem during the winding of small-sized flat wires, making it possible to manufacture micro coils using thin flat wires. The layered winding structure increases the conductor filling density per unit space, providing a higher power density winding 10 solution for applications such as axial flux motors. The setting of the wire replacement layer 20 ensures the reliability of interlayer conductivity while avoiding the space waste of traditional jumper methods.

[0048] This embodiment sets up a multi-layer winding 10, in which each layer of winding 10 is wound with flat wire along the long side of the cross-section of the flat wire parallel to the axis around which the coil is wrapped. A switching layer 20 is set between two adjacent layers of winding 10 to realize the electrical connection between the two adjacent layers of winding 10. This improves the flexibility of the winding 10 connection and has the advantages of avoiding material tearing, improving space utilization and facilitating maintenance and adjustment.

[0049] Optionally, refer to Figure 2 Another embodiment of this utility model provides a flat wire coil, based on the above. Figure 1 In the embodiment shown, the multilayer winding 10 has a first-layer winding 11 and a last-layer winding 12, wherein:

[0050] The first layer winding 11 is provided with a first lead wire 111, and the last layer winding 12 is provided with a second lead wire 121. The first lead wire 111 and the second lead wire 121 are used to connect to external circuits respectively.

[0051] The first winding 11 refers to the outermost starting winding layer of the coil, which can be achieved by continuously winding flat wire from the outermost coil to the innermost coil, serving as the starting end for current input or output. The last winding 12 refers to the innermost terminating winding layer of the coil, which can also be achieved by continuously winding flat wire from the innermost coil to the outermost coil, serving as the ending end for current input or output. The first lead 111 refers to the conductive end extending from the first winding 11, which can be formed by bending the end of a flat wire outwards, used to establish an electrical connection with an external circuit. The second lead 121 refers to the conductive end extending from the last winding 12, which can also be formed by bending the end of a flat wire outwards, used to establish an electrical connection with an external circuit.

[0052] In this design, the first-layer winding 11 and the last-layer winding 12 serve as the start and end points of the coil, respectively. By employing independent lead-out structures, the current input and output paths are clearly separated. The first lead-out 111 of the first-layer winding 11 is located outside the coil, and the second lead-out 121 of the last-layer winding 12 is also located outside the coil. The two are electrically connected across layers via a switching layer 20. Thus, external circuitry can be directly introduced through the first layer and led out through the last layer to complete a closed-loop circuit connection, eliminating the need for cross-layer wiring within the coil and avoiding insulation risks or space occupation issues caused by internal wiring crossover.

[0053] Traditional flat-wound coils typically have leads located on the same winding layer or require complex internal cross-layer connections, resulting in limited wiring positions and increased manufacturing complexity. This embodiment, however, uses layered lead arrangements, allowing for flexible placement of external connections on both the inner and outer sides of the coil. This simplifies the connection process between the coil and external circuits and reduces the risk of circuit breakage due to internal cross-layer connections. This embodiment achieves independent arrangement of leads on the inner and outer sides of the coil, solving the problems of insufficient wiring space and complex manufacturing processes caused by concentrated lead positions in traditional flat-wound coils. It improves the reliability and installation efficiency of the connection between the coil and external circuits, and is particularly suitable for small-sized coils with requirements for space utilization and manufacturing precision.

[0054] Optionally, refer to Figure 3 Another embodiment of this utility model provides a flat wire coil, based on the above... Figure 2 In the embodiment shown, the multilayer winding 10 has two layers, wherein:

[0055] The first layer winding 11 extends counterclockwise from the first lead wire 111 from the outer ring to the inner ring to the first connecting section 21 of the switching layer 20.

[0056] The multi-layer winding 10, consisting of two layers, refers to a coil structure composed of two independently wound layers 10. This can be achieved using a layered winding process, which improves coil space utilization through layered arrangement. Alternatively, it can be wound as a single, continuous flat wire. The first layer winding 11 refers to the outermost starting winding layer 10 in the multi-layer winding 10. This can be achieved using an outer-coil starting winding method, which facilitates lead wire arrangement. The first lead wire 111 refers to the starting end of the first layer winding 11 connecting to the external circuit. This can be achieved through welding or crimping, allowing current input, or it can be a lead segment reserved when winding as a single, continuous flat wire. The counter-clockwise rotation extension from the outer coil to the inner coil refers to the first layer winding 11 being spirally wound from the outer edge of the coil towards the center in a counter-clockwise direction. This can be achieved using a continuous spiral winding path, reducing winding stress through counter-clockwise spiral extension. The first connection segment 21 of the switching layer 20 refers to the connection and transition area between the first winding 11 and the switching layer 20. It can be implemented by a smooth or inclined transition structure, and the interlayer current conduction is completed through the first connection segment 21.

[0057] The first-layer winding 11 starts from the outer end and spirals counterclockwise towards the center of the coil until it reaches the first connecting section 21 of the switching layer 20. During this process, the flat wire is wound vertically with its long side parallel to the axis, making the thin flat wire less prone to tearing during winding. The two-layer winding 10 structure is electrically connected through the switching layer 20. The counterclockwise extension path of the first-layer winding 11 reduces stress concentration during the winding process, while the starting winding method of the outer ring provides space for the arrangement of the lead wires.

[0058] Existing flat winding methods use flat wires with the long side perpendicular to the axis, making thin flat wires prone to tearing at the rounded corners. This embodiment uses a vertical winding method, ensuring the long side of the flat wire is parallel to the axis, avoiding damage caused by winding stress. Existing single-layer windings have low slot fill factor (10 slots). This embodiment addresses this by independently winding two layers, or by winding a single flat wire from the first lead 111 in a single integrated manner, accommodating more turns within the same slot space. Existing coil layer connections are complex. This embodiment achieves a smooth transition between layers through the connection of the wire-changing layers 20, simplifying the winding process. This embodiment makes it possible to wind small-sized thin flat wires, while simultaneously increasing the coil slot fill factor and increasing the conductive cross-sectional area within a limited space, thereby improving the motor's power density. The interlayer wire-changing structure optimizes the current path, reduces contact resistance, and minimizes energy loss. The outer coil starting winding combined with the counter-clockwise extension path effectively prevents deformation or breakage of the flat wire during the winding process.

[0059] Optionally, refer to Figure 4 Another embodiment of this utility model provides a flat wire coil, based on the above... Figure 3In the embodiment shown, the final winding 12 extends counterclockwise from the inner ring to the outer ring from the second connecting section 23 of the switching layer 20 to the second lead 121.

[0060] The last winding 12 refers to the outermost winding 10 in the multi-layer winding 10. It can be made by winding flat wire along the long side of the cross-section parallel to the axis, and is used to form the end of the current loop of the coil. The second connecting section 23 of the switching layer 20 refers to the transition area in the switching layer 20 used to connect the last winding 12. It can be achieved by forming a spatial misalignment with the first connecting section 21 of the first winding 11 through the bending section 22, in order to avoid short circuits between adjacent windings 10 layers. The counterclockwise rotation extension from the inner ring to the outer ring means that the winding path of the last winding 12 is spiraled counterclockwise from the center of the coil to the outer periphery. It can be achieved by controlling the movement trajectory of the flat wire through the winding machine, in order to maintain the insulation distance between the windings 10 layers and optimize the magnetic field distribution.

[0061] In this process, after the final winding 12 completes its electrical connection with the first winding 11 at the second connection section 23 of the switching layer 20, the flat wire extends counterclockwise from the inner coil starting point to the outer coil, eventually reaching the position of the second lead 121. Throughout this process, the long side of the flat wire's cross-section remains parallel to the coil axis, ensuring uniform stress distribution in the wire during winding and preventing tearing of the thin flat wire at corners. Simultaneously, the counterclockwise rotation path forms a symmetrical structure with the extension direction of the first winding 11, ensuring the overall magnetic field symmetry of the coil.

[0062] In existing flat-wound coils, the final winding 12 typically uses a winding method where the long side is perpendicular to the axis, resulting in limited radial dimensions and stress concentration at corners. However, a vertical winding method with counter-clockwise rotation allows for more turns within the same radial space while reducing the sensitivity of the winding process to wire thickness. This embodiment solves the technical problem of existing flat-wound methods being unable to apply thin, flat wires in small-sized coils. By optimizing the winding process feasibility through the counter-clockwise extension path of the final winding 12, it improves slot fill factor while avoiding wire damage, providing a foundation for the miniaturization of axial flux motors.

[0063] Optionally, refer to Figure 2 In another embodiment of this utility model, a flat wire coil is provided, based on the above. Figure 2 In the embodiment shown, the switching layer 20 is located at the inner ring position of the first layer winding 11 and the last layer winding 12.

[0064] The inner ring position refers to the inner annular region closest to the coil along the axis of the winding 10 structure. This can be achieved by arranging the switching layer 20 in the radially inner edge region of the multi-layer winding 10. This arrangement effectively utilizes the internal space of the coil and shortens the electrical connection path. The switching layer 20 is a functional structural layer used to achieve conductive transition between adjacent winding layers 10. It can be implemented using a bent flat wire segment, and its position directly affects the compactness and electrical performance of the coil winding 10.

[0065] When a switching layer 20 is provided at the inner ring position of the first winding 11 and the last winding 12, the ends of adjacent winding layers 10 are electrically connected through this switching layer 20. Since the inner ring position is located radially inside the winding structure 10, the bending transition area of ​​the switching layer 20 can be confined within a limited space, preventing an increase in the overall coil size due to the outward expansion of the transition section. Furthermore, the switching layer 20 at the inner ring position directly connects the start and end ends of adjacent windings 10, ensuring that the turning point of the current conduction path is located in the core region inside the coil, thereby reducing ineffective extension during the winding process.

[0066] In conventional flat-wound coils, the switching layer 20 is typically located on the outer or middle portion of the coil, resulting in additional space being occupied in the transition area and an extended winding path. In this embodiment, however, the switching layer 20 is confined to the inner portion, making the overall coil structure more compact and shortening the length of the interlayer connecting conductors in the winding 10 by optimizing the conductive path.

[0067] Through the above technical solution, this embodiment solves the problem of insufficient winding space caused by improper arrangement of the switching layer 20 in small-sized coils, and achieves a higher density of winding 10 arrangement under the same tooth and slot size. In addition, the short path design of the inner switching layer 20 reduces the resistance loss of the connection between winding layers 10, providing a structural basis for the application of thin flat wire in small-sized coils.

[0068] Optionally, refer to Figure 5 Another embodiment of this utility model provides a flat wire coil, based on the above. Figure 1 In the embodiment shown, the line-changing layer 20 includes a first connecting section 21, a bending section 22, and a second connecting section 23, wherein:

[0069] The first connecting segment 21 and the second connecting segment 23 respectively connect two adjacent windings 10, and the bending segment 22 is used to form a transition region winding 10 for connecting the first connecting segment 21 and the second connecting segment 23.

[0070] The first connecting segment 21 refers to the connection position between the end of the upper winding 10 and the switching layer 20. This can be achieved by welding or mechanical crimping, or by crimping a flat wire segment extending from a single flat wire during integral winding. The first connecting segment 21 is used to conduct current from the upper winding 10 to the switching layer 20. The bending segment 22 refers to the transition area with a bent shape in the switching layer 20. This can be achieved by mold forming or bending process using a winding machine, and is used to change the direction of the conductor and reduce stress concentration. The second connecting segment 23 refers to the connection position between the switching layer 20 and the starting end of the lower winding 10. This can be achieved using the same connection method as the first connecting segment 21, and is used to conduct current from the switching layer 20 to the lower winding 10.

[0071] During the winding process, the end of the upper winding 10 is fixedly connected to the switching layer 20 via the first connecting section 21. The conductor then changes its extension direction via the bending section 22, forming a smooth transition, and finally connects to the starting end of the lower winding 10 via the second connecting section 23. The bending radius and angle of the bending section 22 can be adjusted according to the flat wire size to prevent deformation or breakage of the conductor during bending. Thus, adjacent windings 10 are electrically connected via the switching layer 20, while the mechanical stress in the transition area is dispersed, thereby improving the overall reliability of the windings 10.

[0072] Compared to existing technologies, traditional flat winding methods typically employ direct bending or stacking during layer transitions, which can easily lead to tearing of the flat wire due to stress concentration at the bend. This embodiment, however, by incorporating a layer 20 with a bending section 22, clearly defines the connection position and transition area, making the wire bending process controllable and ensuring uniform stress distribution, thus reducing the risk of flat wire damage. This embodiment optimizes the connection structure between adjacent winding layers (10 layers), solving the problem of flat wire being susceptible to mechanical stress damage in the layer transition area, while simultaneously improving the stability of the winding process and the reliability of the coil.

[0073] Optionally, refer to Figure 6 Another embodiment of this utility model provides a flat wire coil, based on the above... Figure 1 In the embodiment shown, the diameter of the flat wire is 3mm.

[0074] The wire diameter refers to the width of the flat wire's cross-section, which can be achieved using a rectangular cross-section flat wire, with its long side parallel to the axis around which the coil is wound. This dimensional parameter balances mechanical strength and winding feasibility in vertical winding processes by limiting the lateral dimension of the flat wire, and also limits the height of each winding layer. The 3mm wire diameter setting ensures that the flat wire has sufficient bending resistance when winding small-sized coils, while avoiding an increase in coil volume due to excessive size.

[0075] In the vertical winding process, when the long side of the flat wire is wound parallel to the coil axis, the bending stress borne by the 3mm diameter flat wire in the long side direction is effectively dispersed during the winding process through the core. This dimension allows the flat wire to maintain the stability of its cross-sectional shape when passing through the coil corners, avoiding material deformation or breakage caused by local stress concentration. At the same time, this wire diameter matches the radius of curvature of the coil core, enabling a tight fit between the layers of flat wire windings 10.

[0076] Compared to existing technologies, in conventional flat winding processes, when the long side of the flat wire is perpendicular to the axis, the thickness of the short side corresponding to a 3mm wire diameter is easily too thin, leading to winding tearing. However, this embodiment changes the winding direction so that the long side corresponding to a 3mm wire diameter becomes the stress-bearing surface. This structural change increases the effective thickness of the flat wire that can withstand bending stress at the same wire diameter, thereby breaking through the limitations of flat winding processes on wire diameter.

[0077] This embodiment effectively solves the technical problem of thin flat wire being easily torn during the winding of small-sized coils. While ensuring coil compactness, it makes multi-layer vertical winding using flat wire with a diameter of 3mm possible. The synergistic effect of this wire diameter parameter and the vertical winding process maintains the mechanical integrity of the coil structure while achieving efficient utilization of the winding space.

[0078] Optionally, refer to the actual Figure 6 In another embodiment of the present invention, a flat wire coil is provided, based on the above... Figure 1 In the embodiment shown, the thickness of the flat wire is 0.2 mm.

[0079] The thickness of the flat wire refers to its dimension perpendicular to the long side of the cross-section. It can be achieved by cold rolling copper to the target size. This parameter directly affects the material's resistance to bending during the winding process. In vertical winding, the thickness parameter is matched with the radius of the winding core to ensure that the flat wire does not tear at the bend and to maintain the compactness of the overall coil structure.

[0080] By controlling the thickness of the flat wire to the level of 0.2mm, a smaller winding radius of curvature can be achieved in the vertical winding process. When the flat wire is layered and wound parallel to the coil axis along its long side, this thickness makes the stress distribution of the flat wire at the core corner more uniform, avoiding material damage caused by local stress concentration. At the same time, this thickness works synergistically with the multi-layer winding 10 structure, allowing the conductive cross-sectional area of ​​the coil to be increased by increasing the number of winding layers 10, while ensuring the mechanical strength of the single-layer winding 10.

[0081] Compared to existing technologies, traditional flat winding processes typically require a flat wire thickness of at least 0.5 mm to prevent bending and cracking. This embodiment, however, combines vertical winding with a specific thickness, reducing material thickness while still meeting winding reliability requirements. In existing technologies, thicker flat wires increase the radial dimension of the coil, while this embodiment allows for a greater number of turns within the same radial space.

[0082] Through the above technical solution, this embodiment effectively solves the structural failure problem of ultra-thin flat wire during the winding process, making it possible to manufacture small-sized coils using 0.2mm thick flat wire. This thickness parameter, combined with the vertical winding process, significantly improves the space utilization of the coil, achieving a higher slot fill factor in the stator slots of the axial flux motor, while maintaining the electrical performance and mechanical stability of the winding 10.

[0083] This utility model also proposes an electric motor, which includes a flat wire coil as described in the above embodiments.

[0084] It is worth noting that since the motor of this utility model is based on the above-mentioned flat wire coil, the embodiments of the motor of this utility model include all the technical solutions of all the embodiments of the above-mentioned flat wire coil, and the technical effects achieved are exactly the same, so they will not be repeated here.

[0085] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A flat wire coil, characterized in that, The flat wire coil includes: Multi-layer winding, each layer of winding is made of flat wire wound along the long side of the cross-section of the flat wire parallel to the axis around which the coil is wrapped; A switching layer is disposed between two adjacent winding layers, and the switching layer provides electrical connection between the two adjacent winding layers.

2. The flat wire coil as described in claim 1, characterized in that, The multi-layer winding has a first-layer winding and a last-layer winding; The first layer winding is provided with a first lead wire, and the last layer winding is provided with a second lead wire. The first lead wire and the second lead wire are used to connect to external circuits respectively.

3. The flat wire coil as described in claim 2, characterized in that, The multi-layer winding consists of two layers. The first layer winding extends counterclockwise from the first lead wire from the outer ring to the inner ring to the first connecting section of the switching layer.

4. The flat wire coil as described in claim 3, characterized in that, The last winding extends counterclockwise from the inner ring to the outer ring from the second connecting section of the switching layer to the second lead wire.

5. The flat wire coil as described in claim 2, characterized in that, The switching layer is located on the inner ring of the first winding and the last winding.

6. The flat wire coil as described in claim 1, characterized in that, The switching layer includes a first connecting section, a bending section, and a second connecting section. The first connecting section and the second connecting section respectively connect two adjacent windings. The bending section is used to form a transition region winding for connecting the first connecting section and the second connecting section.

7. The flat wire coil as described in claim 1, characterized in that, The diameter of the flat wire is 3mm.

8. The flat wire coil as described in claim 1, characterized in that, The thickness of the flat wire is 0.2 mm.

9. The flat wire coil as described in claim 1, characterized in that, Each layer of the winding includes multiple turns of flat wire, with a self-adhesive coating between adjacent turns of flat wire to allow the adjacent turns of flat wire to be adhered and fixed to each other.

10. An electric motor, characterized in that, The motor includes a flat wire coil as described in any one of claims 1 to 9.

Images