Method for manufacturing a hollow cup flexible winding and a hollow cup electric machine

Abstract

The application relates to the technical field of hollow cup motor, in particular to a preparation method of a hollow cup flexible winding, which comprises the following steps: S100, selecting a flexible copper-clad plate as a base material, the base material being composed of a copper foil layer and an insulating base film located on one side of the copper foil layer; S200, coating photoresist on the side of the copper foil layer away from the insulating base film, and exposing and developing through a mask plate, so that the copper foil layer of the region to be formed into a groove body is exposed, the copper foil layer of the region to be formed into a winding is covered and protected by the photoresist, and the remaining photoresist pattern has a preset sidewall steepness; S300, placing the base material in step S200 in an etching liquid to etch the exposed copper foil layer until the insulating base film is exposed, and a planar winding structure in which the conductor part and the wire slot part are alternately arranged. A hollow cup motor is also provided, the hollow cup motor is installed with a hollow cup flexible winding prepared by a photoetching process, so that the ratio of the slot depth to the width of the wire slot part reaches 5:1 to 20:1, and the full slot rate is improved to more than 90%.

Description

Technical Field

[0001] This invention relates to the field of hollow cup motor technology, and in particular to a method for preparing a hollow cup flexible winding and a hollow cup motor. Background Technology

[0002] In related technical fields, coreless motors are particularly suitable for applications requiring high power density, small size, and fast response, such as robot joint motors, drive motors for minimally invasive medical devices, and aerospace servos, due to their high power density, cogging-free effect, and fast response.

[0003] Currently, the mainstream winding manufacturing process for coreless motors is wire winding, which uses enameled wire with a circular cross-section. A multi-head winding machine and customized precision molds are used to wind the circular wire into a cup-shaped structure through mechanical tension, followed by binding and impregnation for insulation. However, this winding manufacturing process has a drawback: Firstly, since enameled wire is a round wire, there are unavoidable triangular gaps between the round wires during the winding process. Currently, the filling rate can only reach an upper limit of 78%, which limits the conductor cross-sectional area and prevents the motor power density from being further improved. Secondly, multi-pole windings, due to the increasing number of poles and the more complex the winding path, place exponentially higher demands on mold precision and winding machine wiring algorithms, thus limiting the yield of coreless motors.

[0004] Therefore, a new technical solution needs to be researched to address the above problems. Summary of the Invention

[0005] In view of this, the present invention addresses the deficiencies of the prior art, and its main objective is to provide a method for preparing a hollow cup flexible winding, which effectively solves the technical defects of low power density and low yield caused by the use of enameled wire in the winding of the hollow cup motor.

[0006] This invention provides a method for preparing a hollow cup flexible winding, including... Step S100: Select flexible copper-clad laminate as substrate. The substrate is composed of a copper foil layer and an insulating base film located on one side of the copper foil layer. Step S200: Photoresist is coated on the side of the copper foil layer away from the insulating base film, and exposed and developed through a mask, so that the copper foil layer in the area to be formed of the groove is exposed, and the copper foil layer in the area to be formed of the winding is covered and protected by photoresist, and the retained photoresist pattern has a preset sidewall steepness. In step S300, the substrate from step S200 is placed in an etching solution to etch the exposed copper foil layer until the insulating base film and the planar winding structure with alternating conductor and slot sections are exposed. Step S400: The planar winding structure is continuously wound from the inside out into a single multi-layer cylindrical structure. Alternatively, the planar winding structure is wound from a single cylindrical structure to form a single-layer hollow cup; and multiple single-layer hollow cups are prepared and coaxially nested from the inside to the outside to form a multi-layer nested cylindrical structure.

[0007] As a preferred embodiment, the method further includes step S500, which involves leading out electrical connection terminals from a single multi-layer cylindrical structure or a multi-layer nested cylindrical structure to obtain a hollow cup flexible winding.

[0008] The beneficial effects of the hollow cup flexible winding preparation method provided by the present invention are as follows: Compared with the prior art, firstly, a planar winding structure is obtained by photolithography, and then the planar winding structure is wound into a hollow cup flexible winding; this preparation method does not require the use of enameled wire to wind the winding, thereby completely solving the gaps existing in enameled wire winding, and the full slot ratio can be increased by more than 30%, so that the conductor cross-sectional area of ​​the hollow cup flexible winding can be increased by more than double under the same volume, and higher power density and torque density can be achieved under the same voltage; Secondly, with the elimination of gaps, the amount of copper filled in the same volume is maximized, breaking the geometric limitations of round wire in traditional technology, reducing the DC resistance and copper loss of the winding, and enabling the hollow cup motor to develop towards higher speed and higher power density. Thirdly, using photolithography to replace the traditional winding process of enameled wire eliminates the need for high-precision multi-head winding machines and extremely complex wiring algorithms, as well as the need for specially made precision molds; this not only improves production efficiency but also increases production yield.

[0009] As a preferred embodiment, in step S400, the single-layer multi-layer cylindrical structure or multi-layer nested cylindrical structure is isolated from the inside out by an insulating base film, and the two layers are fixed together by an interlayer adhesive or a hot-pressing process.

[0010] As a preferred embodiment, in step S200, a thick-film photolithography process is used, wherein the thickness of the photoresist is greater than or equal to 50% of the thickness of the copper foil layer; Exposure is performed using ultraviolet parallel light or laser direct writing, with the exposure energy controlled at 80 mJ / cm². 2 ~150mJ / cm 2 between.

[0011] As a preferred embodiment, the insulating base film is polyimide or liquid crystal polymer. In step S300, acidic copper chloride or alkaline ammonia solution is used as the etchant. By adjusting the spray pressure and liquid temperature, the etching factor is controlled between 2.0 and 4.0, so that the ratio of conductor height to conductor width of each conductor cross-sectional area is greater than or equal to 1:1.

[0012] As a preferred option, the ratio of groove depth to groove width in the groove section is greater than 1:1.

[0013] As a preferred option, the ratio of groove depth to groove width in the groove section is 5:1, 10:1, 15:1, or 20:1.

[0014] As a preferred embodiment, in step S200, the groove portion formed by photolithography patterning is arranged in a serpentine topology on the plane. The serpentine topology is composed of a plurality of continuous U-shaped bends connected end to end, so that the conductor portion formed after etching extends periodically back and forth on the plane.

[0015] As a preferred embodiment, in step S200, the groove portion formed by photolithography is arranged in a vortex topology on the plane. The vortex topology is arranged in the form of an Archimedean spiral or a concentric square spiral, so that the conductor portion formed after etching extends in an involute shape on the plane.

[0016] The present invention also provides a hollow cup motor, comprising a hollow cup flexible winding prepared by the method described above.

[0017] The beneficial effects of the hollow cup motor provided in this application are as follows: Compared with the prior art, the hollow cup motor is equipped with a hollow cup flexible winding made by photolithography, which makes the ratio of slot depth to width of the slot section reach 5:1 to 20:1, and the conductor section presents a rectangular cross section with a high depth-to-width ratio. This structure completely eliminates the triangular gaps that are unavoidable in traditional round wire winding, increases the slot fill rate to over 90%, maximizes the amount of copper material filling in the limited stator space, thereby significantly reducing winding resistance and copper loss, and enabling the hollow cup motor to have higher torque output capacity and power density in the same volume. At the same time, it greatly reduces the process difficulty, avoids scrap rate caused by tension loss or path error, and makes the production yield of high-pole hollow cup motors high and the mass production stability excellent. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, 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 application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1This is a cross-sectional view of the substrate obtained by the method for preparing the hollow cup flexible winding provided in the first embodiment of this application; Figure 2 yes Figure 1 The method for fabricating a hollow cup flexible winding is illustrated by photolithography of the groove section with a vortex topology arrangement. Figure 3 yes Figure 2 The method for fabricating the hollow cup flexible winding shown is illustrated by photolithography of the groove portion with a vortex topology arrangement. Figure 4 yes Figure 1 The method for fabricating a hollow cup flexible winding is illustrated by photolithography of the groove section with a serpentine topological arrangement. Figure 5 yes Figure 3 The method for preparing the hollow cup flexible winding shown in the figure produces a single multi-layer cylindrical structure from the planar winding structure. Figure 6 yes Figure 5 The method for preparing the hollow cup flexible winding shown is to produce a single multi-layer cylindrical structure from the planar winding structure. (Partial enlarged view at point A) Figure 7 yes Figure 3 The front view of the method for fabricating hollow cup flexible windings shows how a planar winding structure is made into a multi-layered nested cylindrical structure. Figure 8 yes Figure 7 The method for preparing the hollow cup flexible winding shown is to fabricate a multi-layer nested cylindrical structure from the planar winding structure. (Partial enlarged view at point B) Figure 9 This is a three-dimensional structural schematic diagram of the hollow cup motor provided in the third embodiment; Figure 10 yes Figure 9 The cross-sectional view of the hollow cup motor shown; The following are the labeling elements in the figure: 100. Planar winding structure; 10. Substrate; 11. Copper foil layer; 12. Insulating base film; 13. Conductor section; 14. Corrugated section; 141. Serpentine topology arrangement; 142. Vortex topology arrangement; 200. Single-unit multi-layer cylindrical structure; 300. Multi-layer nested cylindrical structure; 20. Hollow cup motor; 21. Main body shell; 211. First opening; 212. Mounting chamber; 213. Second opening; 214. Bottom cover; 215. Bearing; 22. Rotating shaft; 221. Magnet; 23. Iron core; H1, slot depth; W1, slot width; H2, conductor height; W2, conductor width. Detailed Implementation

[0020] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0021] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0022] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0024] In the description of this specification, the references to "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples" indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0026] Please refer to the following: Figures 1 to 8 The preparation method of the hollow cup flexible winding provided in the first embodiment of this application will now be described.

[0027] The method for preparing a hollow cup flexible winding includes the following steps: Step S100: Select a flexible copper-clad laminate as the substrate 10. The substrate 10 is composed of a copper foil layer 11 and an insulating base film 12 located on one side of the copper foil layer 11. In step S200, photoresist is coated on the side of the copper foil layer 11 away from the insulating base film 12, and exposed and developed through a mask, so that the copper foil layer 11 in the area to be formed of the trench is exposed, and the copper foil layer 11 in the area to be formed of the winding is covered and protected by photoresist, and the retained photoresist pattern has a preset sidewall steepness. In step S300, the substrate 10 from step S200 is placed in an etching solution to etch the exposed copper foil layer 11 until the insulating base film 12 is exposed, forming a planar winding structure 100 in which the conductor portion 13 and the slot portion 14 are arranged alternately. Step S400: The planar winding structure 100 is continuously wound from the inside out into a single multi-layer cylindrical structure 200. Alternatively, the planar winding structure 100 is wound from a single cylindrical structure to form a single-layer hollow cup body; and multiple single-layer hollow cup bodies are prepared and coaxially assembled from the inside to the outside to form a multi-layer nested cylindrical structure 300. Specifically, compared with the prior art, firstly, a planar winding structure 100 is obtained through photolithography, and then the planar winding structure 100 is wound into a hollow cup flexible winding. This preparation method does not require the use of enameled wire to wind the winding, thus completely solving the gaps existing in the enameled wire winding. The full slot ratio can be increased by more than 30%, so that the conductor cross-sectional area of ​​the hollow cup flexible winding can be more than doubled in the same volume, and higher power density and torque density can be achieved under the same voltage. Secondly, with the elimination of gaps, the amount of copper filled in the same volume is maximized, breaking the geometric limitations of round wire in traditional technology, reducing the DC resistance and copper loss of the winding, and enabling the hollow cup motor 20 to develop towards higher speed and higher power density. Thirdly, using photolithography to replace the traditional winding process of enameled wire eliminates the need for high-precision multi-head winding machines and extremely complex wiring algorithms, as well as the need for specially made precision molds; this not only improves production efficiency but also increases production yield.

[0028] More specifically, it also includes step S500, which involves leading out electrical connection terminals from the single multi-layer cylindrical structure 200 or the multi-layer nested cylindrical structure 300 to obtain a hollow cup flexible winding.

[0029] Preferably, in step S400, the single-layer multi-layer cylindrical structure 200 or the multi-layer nested cylindrical structure 300 are separated from the inside out by an insulating base film 12, and the two layers are fixed together by an interlayer adhesive or a hot-pressing process. In step S200, a thick-film photolithography process is used, and the thickness of the photoresist is greater than or equal to 50% of the thickness of the copper foil layer 11; exposure is performed using ultraviolet parallel light or laser direct writing, and the exposure energy is controlled at 80 mJ / cm². 2 ~150mJ / cm 2 between.

[0030] Furthermore, the insulating base film 12 is polyimide or liquid crystal polymer; in step S300, acidic copper chloride or alkaline ammonia solution is used as the etchant, and the etching factor is controlled between 2.0 and 4.0 by adjusting the spray pressure and liquid temperature; so that the ratio of conductor height H2 to conductor width W2 of the cross-sectional area of ​​each conductor portion 13 is greater than or equal to 1:1. At the same time, the ratio of groove depth H1 to groove width W1 of the groove portion 14 is greater than 1:1.

[0031] It should be noted that the ratio of conductor height to conductor width in each conductor section 13 can be 1:1, 2:1, 3:1, 4:1, etc.; the ratio of slot depth H1 to slot width W1 in the slot section 14 can be 5:1, 10:1, 15:1, 20:1, etc. The slot width W1 of the slot section 14 can be less than 10μm, and the conductor width of the conductor section 13 is greater than the slot width of the slot section 14, with the conductor width being at least twice the slot width. This structure enables an extremely high aspect ratio, allowing the conductor sections 13 to be arranged closely with an approximately rectangular cross-section, eliminating the gap problem present in the use of enameled wire in traditional technology. With the elimination of gaps, the amount of copper filled in the same volume is maximized, resulting in a multiple increase in cross-sectional area, reducing the DC resistance and copper loss of the winding, and enabling the hollow cup motor to develop towards higher speeds and higher power densities.

[0032] In the first embodiment of this application, the groove portion 14 formed by photolithography patterning has at least two photolithography paths; wherein, the first path is that in step S200, the groove portion 14 formed by photolithography patterning is arranged in a serpentine topology 141 on the plane, the serpentine topology is composed of a plurality of continuous U-shaped bends connected end to end, so that the conductor portion 13 formed after etching extends periodically back and forth on the plane.

[0033] The second approach is that in step S200, the groove portion 14 formed by photolithography is arranged in a vortex topology 142 on the plane. The vortex topology is arranged in the form of an Archimedean spiral or a concentric square spiral, so that the conductor portion 13 formed after etching extends in an involute shape on the plane.

[0034] Compared to the enameled wire winding structure in traditional technology, this structure allows for the adoption of different topologies according to actual needs, enabling the distribution of the air gap magnetic field in the motor to be closer to an ideal sine wave, thus eliminating the distortion of back electromotive force at its source. Furthermore, the smooth magnetic field ensures that the resistance received by the rotor during rotation is uniform and continuous, which not only significantly reduces vibration and harsh electromagnetic noise during motor operation but also makes the torque output more delicate, making it particularly suitable for high-precision medical equipment and robot joints.

[0035] Second Embodiment The second embodiment of this application provides a method for preparing a hollow cup flexible winding, the method comprising the following steps. Step S100: Select a flexible copper-clad laminate as substrate 10, which is defined as the first substrate; Step S200: Photoresist is coated on the front side of the first substrate, and exposed and developed through a mask to expose the copper foil layer 11 in the area to be formed of the trench, while the copper foil layer 11 in the area to be formed of the winding is covered and protected by photoresist, and the retained photoresist pattern has a preset sidewall steepness. In step S300, the first substrate from step S200 is placed in an etching solution to etch the exposed copper foil layer 11, forming a planar winding structure 100 in which conductor portions 13 and groove portions 14 are arranged alternately. Step S400: Select a flexible copper-clad laminate as substrate 10, which is defined as the second substrate; In step S500, photoresist is coated on the front side of the second substrate and exposed and developed through a mask to expose the copper foil layer 11 in the area to be formed of the trench, while the copper foil layer 11 in the area to be formed of the winding is covered and protected by photoresist, and the retained photoresist pattern has a preset sidewall steepness. In step S600, the second substrate from step S500 is placed in an etching solution to etch the exposed copper foil layer 11, forming a planar winding structure 100 in which conductor portions 13 and groove portions 14 are arranged alternately. In step S700, the first substrate and the second substrate are pressed together so that the conductor portion 13 of the first substrate and the second substrate are coaxially arranged and the groove portion 14 of the first substrate and the second substrate are coaxially arranged, so that the two planar winding structures 100 are pressed into a single planar winding structure 100, and an insulating base film 12 is pressed onto the surface of the first substrate or the second substrate. Step S800: The planar winding structure 100 is continuously wound from the inside out into a single multi-layer cylindrical structure 200. Alternatively, the planar winding structure 100 is wound from a single cylindrical structure to form a single-layer hollow cup body; and multiple single-layer hollow cup bodies are prepared and coaxially assembled from the inside to the outside to form a multi-layer nested cylindrical structure 300. S900, an electrical connection terminal is led out from the single multi-layer cylindrical structure 200 or the multi-layer nested cylindrical structure 300 to obtain a hollow cup flexible winding.

[0036] Specifically, by photolithographically etching planar winding structures 100 on the first substrate and the second substrate respectively, and then pressing the first substrate and the second substrate together, the ratio of the groove depth H1 to the groove width W1 of the slot portion 14 and the ratio of the conductor height H2 to the conductor width W2 of the conductor portion 13 cross-sectional area can be further expanded. The modular superposition of conductor thickness is achieved through the pressing of the double-layer photolithographic structure, which significantly improves the current carrying capacity and structural reliability of the hollow cup flexible winding while meeting the requirements of high depth-to-width ratio slots.

[0037] It should be noted that the preparation method of the hollow cup flexible winding provided in the second embodiment of this application is roughly the same as the preparation method of the hollow cup flexible winding provided in the first embodiment. The difference is that the preparation method of the hollow cup flexible winding provided in the second embodiment adds a first substrate and a second substrate, as well as the pressing and molding of the first substrate and the second substrate.

[0038] Third Embodiment Please refer to the following: Figures 9 to 10 The third embodiment of this application provides a hollow cup motor 20, which is equipped with a hollow cup flexible winding prepared by the preparation method of the hollow cup flexible winding of the first embodiment or the preparation method of the hollow cup flexible winding of the second embodiment.

[0039] In the third embodiment of this application, the hollow cup motor 20 includes a main body shell 21, a rotating shaft 22, an iron core 23, and a flexible hollow cup winding. The top of the main body shell 21 has a first opening 211, and the interior has a mounting chamber 212 for mounting components. The mounting chamber 212 is electrically connected to the first opening 211. The mounting chamber 212 extends downward through the bottom of the main body shell 21 to form a second opening 213, and a bottom cover 214 is installed in the second opening 213. Bearings 215 are installed in both the first opening 211 and the bottom cover 214. The two ends of the rotating shaft 22 are installed corresponding to the bearings 215, and the rotating shaft 22 extends outward through the first opening 211. A magnet 221 is provided on the outer surface of the rotating shaft 22. The iron core 23 is installed in the mounting chamber 212, and the magnet 221 and the iron core 23 are spaced apart. The hollow cup flexible winding is installed on the inner surface of the iron core 23 and is spaced apart from the magnet 221.

[0040] Specifically, the hollow cup motor 20 is equipped with a hollow cup flexible winding fabricated by photolithography, which makes the ratio of the slot depth H1 to the width of the slot portion 14 reach 5:1 to 20:1, and the conductor portion 13 presents a rectangular cross-section with a high aspect ratio. This structure completely eliminates the triangular gaps that are unavoidable in traditional round wire winding, increases the slot fill rate to over 90%, maximizes the amount of copper material filling in the limited stator space, thereby significantly reducing winding resistance and copper loss, enabling the hollow cup motor 20 to have higher torque output capability and power density in the same volume. At the same time, it greatly reduces the process difficulty and avoids the scrap rate caused by tension loss or path error, resulting in high production yield and good mass production stability of the high pole number hollow cup motor 20.

[0041] The above are merely preferred embodiments of the present invention, and only specifically describe the technical principles of the present invention. These descriptions are only for explaining the principles of the present invention and should not be construed as limiting the scope of protection of the present invention in any way. Based on this explanation, any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention, as well as other specific embodiments of the present invention that can be conceived by those skilled in the art without creative effort, should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a hollow cup flexible winding, comprising: Step S100: Select flexible copper clad laminate as substrate (10). The substrate (10) is composed of copper foil layer (11) and insulating base film (12) located on one side of copper foil layer (11). Its features are, Step S200: Photoresist is coated on the side of the copper foil layer (11) away from the insulating base film (12), and exposed and developed through a mask, so that the copper foil layer (11) in the area to be formed of the trench is exposed, and the copper foil layer (11) in the area to be formed of the winding is covered and protected by photoresist, and the retained photoresist pattern has a preset sidewall steepness. In step S300, the substrate (10) from step S200 is placed in an etching solution to etch the exposed copper foil layer (11) until the insulating base film (12) and the planar winding structure (100) with alternating conductor portions (13) and groove portions (14) are exposed. Step S400: The planar winding structure (100) is continuously wound from the inside out into a single multi-layer cylindrical structure (200). Alternatively, the planar winding structure (100) is wound from a single cylindrical structure to form a single-layer hollow cup body; and multiple single-layer hollow cup bodies are prepared and coaxially assembled from the inside to the outside to form a multi-layer nested cylindrical structure (300).

2. The method for preparing a hollow cup flexible winding according to claim 1, characterized in that, It also includes step S500, which leads out electrical connection terminals to the single multi-layer cylindrical structure (200) or the multi-layer nested cylindrical structure (300) to obtain a hollow cup flexible winding.

3. The method for preparing a hollow cup flexible winding according to claim 2, characterized in that, In step S400, the single multilayer cylindrical structure (200) or multilayer nested cylindrical structure (300) is isolated from the inside out by an insulating base film (12), and the two layers are fixed together by interlayer adhesive or hot pressing process.

4. The method for preparing a hollow cup flexible winding according to claim 2 or 3, characterized in that, In step S200, a thick-film photolithography process is used, and the thickness of the photoresist is greater than or equal to 50% of the thickness of the copper foil layer (11); Exposure is performed using ultraviolet parallel light or laser direct writing, with the exposure energy controlled at 80 mJ / cm². 2 ~150mJ / cm 2 between.

5. The method for preparing a hollow cup flexible winding according to claim 4, characterized in that, The insulating base film (12) is a polyimide or liquid crystal polymer. In step S300, acidic copper chloride or alkaline ammonia solution is used as the etchant. By adjusting the spray pressure and liquid temperature, the etching factor is controlled between 2.0 and 4.0, so that the ratio of conductor height to conductor width of each conductor cross-sectional area is greater than or equal to 1:

1.

6. The method for preparing a hollow cup flexible winding according to claim 5, characterized in that, The ratio of groove depth (H1) to groove width (W1) of the groove section (14) is greater than 1:

1.

7. The method for preparing a hollow cup flexible winding according to claim 6, characterized in that, The ratio of groove depth (H1) to groove width (W1) of the groove section (14) is 5:1, 10:1, 15:1 or 20:

1.

8. The method for preparing a hollow cup flexible winding according to claim 1, characterized in that, In step S200, the groove portion (14) formed by photolithography patterning is arranged in a serpentine topology on the plane (141). The serpentine topology is composed of a plurality of continuous U-shaped bends connected end to end, so that the conductor portion (13) formed after etching extends periodically back and forth on the plane.

9. The method for preparing a hollow cup flexible winding according to claim 1, characterized in that, In step S200, the groove portion (14) formed by photolithography is arranged in a vortex topology on the plane (142). The vortex topology is arranged in an Archimedean spiral or a concentric square spiral, so that the conductor portion (13) formed after etching extends in an involute shape on the plane.

10. A hollow cup motor, characterized in that, This includes hollow cup flexible windings prepared by the method for preparing hollow cup flexible windings according to any one of claims 2-9.

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