Slotless stator coil device and brushless slotless motor

Abstract

The utility model belongs to the technical field of motors, and particularly relates to a slotless stator coil device and a brushless slotless motor. The slotless stator coil device comprises a plurality of coil structures, and the plurality of coil structures are arranged in a surrounding manner along the circumferential direction to form a cylindrical structure; each coil structure comprises an insulating substrate and multiple layers of coil parts, each layer of coil part is provided with a first connecting end and a second connecting end, each layer of coil part is spirally arranged, the first connecting end is a spiral outer end of the coil part, and the second connecting end is a spiral inner end of the coil part; the first connecting end of the first-layer coil part is arranged to be a positive terminal or a negative terminal of the coil structure, the first connecting end or the second connecting end of the outermost-layer coil part is arranged to be a negative terminal or a positive terminal, and the multiple layers of coil parts are arranged in series. By applying the technical scheme, the problems of performance bottleneck and coil manufacturing difficulty of the miniature brushless slotless motor are solved, and the miniaturization design and even micromation design of the motor are realized.

Description

Technical Field

[0001] This application belongs to the field of motor technology, and in particular relates to a slotless stator coil device and a brushless slotless motor. Background Technology

[0002] Brushless slotless motors are a type of motor that uses electronic commutation technology. Compared to traditional brushed motors, they offer higher efficiency, longer lifespan, and lower noise. With technological advancements, the demand for small and even micro motors is increasing across various industries, leading to ever-rising market requirements for miniaturized or even micro-sized brushless slotless motor designs.

[0003] In traditional brushless slotless motors, the stator windings are formed using copper or aluminum wires. Due to the limitations of the size of copper or aluminum wires and the winding process, the miniaturization design of traditional brushless slotless motors has reached its limit. Utility Model Content

[0004] The purpose of this application is to provide a slotless stator coil device and a brushless slotless motor, aiming to solve the problems of miniaturization or even micro-miniaturization design of brushless slotless motors in related technologies.

[0005] To achieve the above objectives, according to the first aspect of this application, the technical solution adopted by this application is: a slotless stator coil device, comprising multiple coil structures, wherein the multiple coil structures are arranged in a cylindrical structure along the circumferential direction;

[0006] Each coil structure includes an insulating substrate and a multilayer coil section stacked on the insulating substrate. Each coil section has a first connection end and a second connection end. Each coil section is spirally arranged by at least one line. The first connection end is the outer spiral end of the coil section, and the second connection end is the inner spiral end of the coil section. The spiral directions of adjacent coil sections from the first connection end to the second connection end are opposite.

[0007] In the radial direction outward from the axis of the slotless stator coil device of the cylindrical structure, the first connection end of the first layer coil section is set as one of the positive and negative terminals of the coil structure, and the first or second connection end of the outermost coil section is set as the other of the positive and negative terminals of the coil structure. Between two adjacent coil sections, the two first connection ends are electrically connected or the two second connection ends are electrically connected so that the multi-layer coil sections are connected in series.

[0008] The slotless stator coil device provided in this application includes an insulating substrate and multiple layers of coil sections stacked on the insulating substrate, so that each coil structure is formed into a sheet-like structure, greatly reducing the overall thickness of the coil structure. The slotless stator coil device of this application adopts a design structure in which multiple layers of coil sections are stacked on an insulating substrate, and the circuitry of each layer of coil sections is arranged spirally. Compared with traditional stator windings, the circuitry of the coil sections in the slotless stator coil device of this application can be laid out more uniformly and regularly, thereby reducing space waste during the coil section laying process. When multiple coil structures are arranged in a cylindrical shape around the circumference, and given that the slotless stator coil device of this application has the same volume as a conventional stator winding, the coil section of the slotless stator coil device of this application can be laid out more evenly and regularly. Therefore, the slotless stator coil device of this application can lay out more turns of coil, resulting in a higher slot fill factor (a crucial parameter in motor design; a higher slot fill factor increases the motor's power density and efficiency). This enhances the electromagnetic induction intensity, which is beneficial for improving the output power and torque of the brushless slotless motor using this slotless stator coil device. In other words, when the number of turns of the slotless stator coil device of this application is equal to that of a conventional stator winding, the slotless stator coil device of this application can significantly reduce the overall volume of the cylindrical structure, thereby greatly reducing the volume of the stator of the brushless slotless motor using this slotless stator coil device. This, in turn, significantly reduces the overall volume of the brushless slotless motor, achieving the goal of further miniaturization or even micro-miniaturization of the brushless slotless motor. Moreover, compared with traditional stator windings, the design structure of the coil section of the slotless stator coil device of this application is suitable for mass production using industrial manufacturing processes.

[0009] In some embodiments of this application, in each coil structure, the projections of the first connection end and the second connection end of each layer of coil portion on the insulating substrate coincide along the radial direction of the cylindrical structure.

[0010] In some embodiments of this application, at least one line of each layer of coil is formed by additive manufacturing process, and the cross-section of the at least one line is rectangular, trapezoidal or arc-shaped at the top (e.g., similar to the cross-section of a bread).

[0011] In some embodiments of this application, each coil structure includes n layers of coil sections, and n ≥ 2m, where m is a positive integer.

[0012] In some embodiments of this application, along the axial direction of the slotless stator coil assembly, the shape of each coil turn in each layer of the coil section is rectangular, rhomboid, polygonal, racetrack-shaped, or olive-shaped.

[0013] In some embodiments of this application, the line width of at least one line in each layer of coil section is variable in the routing direction, and in the same coil structure, the number of coil turns of any two layers of coil section is equal or unequal.

[0014] In some embodiments of this application, when the shape of each coil turn in each layer of the coil section is racetrack-shaped, the insulating substrate is square, and each layer of the coil section includes multiple straight segments along the length direction of the insulating substrate and multiple variable diameter segments located at both ends of the insulating substrate. The lengths of the multiple straight segments are all equal, and the line width of the straight segments is greater than, equal to or less than the line width of the variable diameter segments.

[0015] In some embodiments of this application, in the same coil structure, the thickness of at least one line in any two coil layers may be equal or unequal.

[0016] In some embodiments of this application, the line thickness of the multilayer coil portion of each coil structure gradually increases radially outward from the axis of the cylindrical structure.

[0017] In some embodiments of this application, the slotless stator coil device further includes an iron core cylinder, which is sleeved and fixed outside the cylindrical structure, and the iron core cylinder is formed by stacking multiple annular magnetic material sheets.

[0018] In some embodiments of this application, the cylindrical structure is composed of multiple layers of cylinders nested in sequence, with each layer having an equal number of coil structures; along the radial direction of the cylindrical structure, the multiple coil structures between adjacent layers of cylinders are arranged in a one-to-one correspondence, or the multiple coil structures between any two adjacent layers of cylinders are circumferentially offset by a predetermined rotation angle in the same direction.

[0019] In some embodiments of this application, the coil structure is provided with stepped ridges. Along the radial direction of the cylindrical structure, the stepped ridges enable the coil structure to form a first coil portion and a second coil portion with a height difference. Furthermore, the height of the stepped ridges is equal to the thickness of the coil structure. In two adjacent coil structures along the circumference of the cylindrical structure, the first coil portion of one coil structure is stacked with the second coil portion of the other coil structure. Multiple coil structures are connected end to end to form a cylindrical structure.

[0020] According to a second aspect of this application, a brushless slotless motor is provided, characterized in that it comprises:

[0021] The casing has assembly space;

[0022] As mentioned above, the slotless stator coil assembly is housed within the assembly space;

[0023] Two bearings are mounted on the housing, and the two bearings are located at both ends of the slotless stator coil assembly;

[0024] The rotor assembly is rotatably mounted on the slotless stator coil assembly, with two bearings mounted at each end of the rotor assembly. Attached Figure Description

[0025] 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.

[0026] Figure 1 This is a three-dimensional structural schematic diagram of a slotless stator coil device according to an embodiment of this application;

[0027] Figure 2 for Figure 1 A top view of the slotless stator coil assembly along its axial direction is shown.

[0028] Figure 3 for Figure 1 A three-dimensional structural schematic diagram of the cylindrical structure of the slotless stator coil device is shown.

[0029] Figure 4 for Figure 3 A top view of the cylindrical structure along its axial direction is shown.

[0030] Figure 5 for Figure 1 A schematic diagram of one layer of the coil structure of a slotless stator coil device is shown.

[0031] Figure 6 for Figure 1 A three-dimensional schematic diagram of the coil structure of the slotless stator coil device is shown. Figure 1 ;

[0032] Figure 7 for Figure 1 A three-dimensional schematic diagram of the coil structure of the slotless stator coil device is shown. Figure 2 ;

[0033] Figure 8 This is a three-dimensional structural schematic diagram of another slotless stator coil device according to an embodiment of this application;

[0034] Figure 9 for Figure 8 A top view of the slotless stator coil assembly along its axial direction is shown.

[0035] Figure 10 This is a three-dimensional structural diagram of a brushless slotless motor according to an embodiment of this application. Figure 1;

[0036] Figure 11 for Figure 10 The diagram shows the three-dimensional structure of a brushless slotless motor. Figure 2 ;

[0037] Figure 12 for Figure 10 The diagram shown is a front view of a brushless slotless motor.

[0038] Figure 13 for Figure 10 An exploded view of a brushless slotless motor is shown.

[0039] Figure 14 for Figure 11 An exploded view of a brushless slotless motor is shown.

[0040] Figure 15 for Figure 12 Cross-sectional view along the AA direction.

[0041] The figures in the diagram are labeled as follows:

[0042] 100. Slotless stator coil assembly;

[0043] 10. Cylindrical structure; 11. Inner cylinder; 12. Outer cylinder; 13. Connecting part;

[0044] 20. Coil structure; 21. Insulating substrate; 22. Coil section; 221. First connecting end; 222. Second connecting end; 223. Straight section; 224. Variable diameter section; 23. Stepped edge; 24. First coil section; 25. Second coil section;

[0045] 30. Iron core cylinder; 31. Thin sheet of magnetic material;

[0046] 41. Positive electrode pad; 42. Negative electrode pad;

[0047] 200. Brushless and slotless motor;

[0048] 210. Housing; 211. Housing body; 212. End cap; 213. Assembly space; 214. Cable outlet;

[0049] 220. Bearings;

[0050] 230. Rotor assembly; 231. Mandrel; 232. Permanent magnet. Detailed Implementation

[0051] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0052] In the description of this application, 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, and 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, and therefore should not be construed as a limitation of this application.

[0053] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0054] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0055] like Figures 1 to 9As shown, the slotless stator coil device 100 provided in the embodiments of this application includes a plurality of coil structures 20, which are arranged in a cylindrical structure 10 around the periphery. Each coil structure 20 includes an insulating substrate 21 and a multilayer coil portion 22 stacked on the insulating substrate 21. Each layer of coil portion 22 has a first connection end 221 and a second connection end 222. Each layer of coil portion 22 is spirally arranged by at least one wire. The first connection end 221 is the outer end of the spiral of the coil portion 22, and the second connection end 222 is the inner end of the spiral of the coil portion 22. The spiral directions of adjacent layers of coil portion 22 from the first connection end 221 to the second connection end 222 are opposite. In the radial direction outward from the axis of the slotless stator coil assembly 100 of the cylindrical structure 10, the first connection end 221 of the first layer coil section 22 is set as one of the positive and negative terminals of the coil structure 20, and the first connection end 221 or the second connection end 222 of the outermost coil section 22 is set as the other of the positive and negative terminals of the coil structure 20. Between two adjacent coil sections 22, the two first connection ends 221 are electrically connected or the two second connection ends 222 are electrically connected so that the multilayer coil sections 22 are connected in series. Furthermore, an insulating layer is provided between two adjacent coil sections 22, that is, the remaining stacked positions between two adjacent coil sections 22 are insulated.

[0056] The slotless stator coil device 100 provided in this application includes an insulating substrate 21 and multiple coil sections 22 stacked on the insulating substrate 21, so that each coil structure 20 is formed into a sheet structure, greatly reducing the overall thickness of the coil structure 20. The coil structure 20 of the slotless stator coil device 100 of this application adopts a design structure in which multiple coil sections 22 are stacked on the insulating substrate 21. The lines of each layer of coil section 22 are arranged in a spiral. Compared with the traditional stator winding, the lines of the coil section 22 of the slotless stator coil device 100 of this application can be laid out more evenly and regularly, thereby reducing the space waste generated during the laying of the coil section 22. When multiple coil structures 20 are arranged in a cylindrical structure 10 around the circumference, and when the slotless stator coil device 100 of this application has the same volume as a conventional stator winding, since the coil section 22 of the coil structure 20 of the slotless stator coil device 100 of this application can be laid out more evenly and regularly, the slotless stator coil device 100 of this application can lay out more turns of coil, that is, the slot fill factor of the coil of the slotless stator coil device 100 of this application is higher (the slot fill factor is an important parameter in motor design, and a higher slot fill factor can increase the power density and efficiency of the motor), thereby enhancing the electromagnetic induction intensity, which is beneficial to improving the output power and torque of the brushless slotless motor 200 using the slotless stator coil device 100. In other words, when the number of turns of the slotless stator coil device 100 of this application is equal to that of a conventional stator winding, the slotless stator coil device 100 of this application can greatly reduce the overall volume of the cylindrical structure 10, thereby greatly reducing the volume of the stator of the brushless slotless motor 200 using the slotless stator coil device 100, and thus greatly reducing the overall volume of the brushless slotless motor 200, thereby achieving the goal of further miniaturization or even micro-miniaturization of the brushless slotless motor 200. Moreover, compared with conventional stator windings, the design structure of the coil section 22 of the coil structure 20 of the slotless stator coil device 100 of this application can be adapted to mass production using industrial manufacturing processes.

[0057] The phrase "each layer of coil section 22 is spirally arranged by at least one wire" means that each layer of coil section 22 can be formed by spirally arranging only one wire, or by spirally arranging multiple wires. When each layer of coil section 22 is spirally arranged by multiple wires, it is called a multi-strand winding method, such as double-strand winding, triple-strand winding, etc.

[0058] In some embodiments of this application, in each coil structure 20 of the slotless stator coil device 100, the projections of the first connecting ends 221 and the second connecting ends 222 of each layer of coil portion 22 on the insulating substrate 21 coincide along the radial direction of the cylindrical structure 10. Since the projections of the first connecting ends 221 and the second connecting ends 222 of the multilayer coil portion 22 on the insulating substrate 21 coincide along the radial direction of the cylindrical structure 10, that is, the overlap of the first connecting ends 221 and the second connecting ends 222 of the multilayer coil portion 22 is high, thus, when each layer of coil portion 22 is formed on the insulating substrate 21, it is convenient to electrically connect the two first connecting ends 221 or the two second connecting ends 222 between adjacent layers of coil portion 22. Furthermore, along the radial direction of the cylindrical structure 10, the projections of all coils of each layer of coil portion 22 on the insulating substrate 21 completely coincide. When forming each layer of coil section 22, each layer of coil section 22 is formed on the insulating substrate 21 using semiconductor manufacturing processes. Therefore, in a coil structure 20, the initially formed multilayer coil sections 22 are separated from each other and completely insulated. Thus, after forming two adjacent layers of coil section 22, holes need to be drilled at the positions of the first connection end 221 and the second connection end 222 between the two adjacent layers of coil section 22, and conductors are inserted into the holes, forming conductive vias (commonly known as vias). This allows the two first connection ends 221 or the two second connection ends 222 between the two adjacent layers of coil section 22 to be electrically connected, ultimately resulting in the multilayer coil sections 22 being connected in series. Since the projections of the first connection ends 221 and the second connection ends 222 of the multilayer coil section 22 onto the insulating substrate 21 along the radial direction of the cylindrical structure 10 coincide, this greatly improves the accuracy of the drilling process, thereby significantly increasing product yield and reducing manufacturing costs.

[0059] In the process of forming each layer of coil portion 22 using semiconductor manufacturing processes, the circuitry of each layer of coil portion 22 is fabricated using additive manufacturing processes. When forming the first layer of coil portion 22 on the insulating substrate 21, a layer of photoresist is first coated on the surface of the insulating substrate 21. Then, the coil portion 22 is projected onto the photoresist, and a groove in the coil shape of the coil portion 22 is formed on the insulating substrate 21 through steps such as laser etching and UV etching. Next, a layer of seed copper is sputtered into the groove using a sputtering process, and then the coil circuitry of the coil portion 22 is additively formed on the basis of the seed copper using an electroplating process. The combination of sputtering and electroplating processes is referred to as additive manufacturing. Furthermore, in the coil structure 20 of the slotless stator coil device of this application embodiment, the cross-section of the circuitry of each layer of coil portion 22 has a rectangular, trapezoidal, or arc-shaped top cross-section (e.g., similar to a bread cross-section). In other words, when the additively manufactured coil exactly fills the slot, and the slot's cross-sectional shape is rectangular or trapezoidal, the cross-sectional shape of the coil section 22 is the same as the slot's cross-sectional shape—rectangular or trapezoidal. When the additively manufactured coil does not fill the slot or slightly exceeds it, the top of the coil section 22's lines is arc-shaped during the additive manufacturing process; that is, the top of the line's cross-section is arc-shaped. After completing the molding of the first layer of coil section 22, the second layer of coil section 22 is molded, and the molding process is the same as that of the first layer. The layer of photoresist coated on the first layer of coil section 22 then becomes the insulating layer between the two adjacent coil sections 22. This process is repeated to fabricate a multilayered coil section 22.

[0060] Furthermore, during the process of forming each layer of coil portion 22 on the insulating substrate 21 using semiconductor manufacturing processes, the insulating substrate 21 is in a flat state, meaning that each layer of coil portion 22 is formed on a plane. This not only reduces the difficulty of forming each layer of coil portion 22 using semiconductor manufacturing processes but also greatly reduces the difficulty of drilling holes, improving the accuracy of electrical connection between the two first connection terminals 221 or the two second connection terminals 222 between adjacent coil portions 22. After the multiple coil structures 20 are fabricated, each coil structure 20 is bent into an arc shape with a predetermined arc angle, thereby arranging the multiple coil structures 20 circumferentially into a cylindrical structure 10. The outer wall of the cylindrical structure 10 is covered with an insulating protective film, which protects the outer wall of the cylindrical structure 10 from damage when moving it and ensures that the cylindrical structure 10 is essentially shaped to prevent the multiple coil structures 20 from loosening and detaching.

[0061] In some embodiments of the slotless stator coil device 100 of this application, each coil structure 20 includes n layers of coil portions 22, and n ≥ 2m, where m is a positive integer. That is, the number of layers of coil portions 22 in the coil structure 20 of the slotless stator coil device 100 can be an even number of layers such as 2, 4, 6, 8, 10, etc. In each coil structure 20, when the multiple coil portions 22 are arranged in series, along the radial direction outward from the axis of the slotless stator coil device 100 of the cylindrical structure 10, the first connection end 221 of the first layer of coil portions 22 is set as one of the positive terminal (i.e., the first connection end 221 of the first layer of coil portions 22 is connected to the positive electrode pad 41 as the positive terminal) and the negative terminal (i.e., the first connection end 221 of the first layer of coil portions 22 is connected to the negative electrode pad 42 as the negative terminal) of the coil structure 20, and the first connection end 221 of the outermost layer of coil portions 22 is set as the other of the positive terminal and the negative terminal of the coil structure 20. In this application, the example is taken where the first connection terminal 221 of the first layer coil section 22 is connected to the positive electrode pad 41 as the positive terminal, and the first connection terminal 221 of the outermost coil section 22 is connected to the negative electrode pad 42. In this way, the positive electrode pad 41 of the coil structure 20 and the first connection terminal 221 of the first layer coil section 22 can be directly connected by leads, and the negative electrode pad 42 of the coil structure 20 and the first connection terminal 221 of the outermost coil section 22 can also be directly connected by leads. Furthermore, the leads between the first connection terminal 221 of the first layer coil section 22 and the positive electrode pad 41, and the leads between the first connection terminal 221 of the outermost coil section 22 and the negative electrode pad 42 are all located on the same side of the insulating substrate 21, which optimizes the wiring design of the coil structure 20 and reduces the wiring difficulty.

[0062] Preferably, in the slotless stator coil device 100 of the embodiments of this application, each coil structure 20 includes 4 layers of coil sections 22 (i.e., m=2).

[0063] In some other embodiments of the slotless stator coil device 100 of this application, the number of layers of coil section 22 in each coil structure 20 may also be an odd number of layers, such as 1, 3, 5, 7, 9, etc. In this case, in each coil structure 20, when multiple coil sections 22 are arranged in series, along the radial direction outward from the axis of the slotless stator coil device 100 of the cylindrical structure 10, the first connecting end 221 of the first layer coil section 22 is set as one of the positive terminal or the negative terminal of the coil structure 20, and the second connecting end 222 of the outermost coil section 22 is set as the other of the positive terminal and the negative terminal of the coil structure 20 (taking the example of the first connecting end 221 of the first layer coil section 22 being set as the positive terminal of the coil structure 20 and the second connecting end 222 of the outermost coil section 22 being set as the negative terminal of the coil structure 20 for explanation). In this embodiment, the positive electrode pad 41 of the coil structure 20 can be directly connected to the first connection terminal 221 of the first layer coil section 22 by lead wire. However, when making a lead wire between the second connection terminal 222 of the outermost coil section 22 and the negative electrode pad 42, it is necessary to drill a hole in the second connection terminal 222 of the outermost coil section 22 and pass it through the insulating substrate 21. Then, a conductor is inserted into the hole, and then a lead wire is made on the other side of the insulating substrate 21 away from the coil section 22 to make an electrical connection with the negative electrode pad 42. That is, the lead wire between the first connection terminal 221 of the first layer coil section 22 and the positive electrode pad 41 and the lead wire between the second connection terminal 222 of the outermost coil section 22 and the negative electrode pad 42 are respectively located on both sides of the insulating substrate 21.

[0064] In some embodiments of the slotless stator coil device of this application, the shape of each spiral coil of each layer of coil section 22 along the axial direction of the slotless stator coil device is rectangular, rhomboid, polygonal, racetrack-shaped, or olive-shaped. Among them, the polygonal includes hexagonal and more polygons, preferably regular polygons.

[0065] In some embodiments of the slotless stator coil apparatus of this application, the line width of the coil section 22 of each layer of the coil structure 20 in the routing direction is variable. That is, while keeping the total resistance of each layer of the coil section 22 substantially constant, the line width of each layer of the coil section 22 can be increased or decreased at any position to meet actual routing requirements. Furthermore, in the same coil structure 20, the number of coil turns of any two layers of the coil section 22 can be equal or unequal. In the embodiments of this application, the number of coil turns of any two layers of the coil section 22 in the same coil structure 20 is preferably equal.

[0066] like Figures 5 to 7As shown, in some embodiments of this application, when the shape of each coil turn in each layer of coil section 22 is racetrack-shaped, the insulating substrate 21 of each coil structure 20 is square along the axial direction of the slotless stator coil device 100. In each coil structure 20, each layer of coil section 22 includes multiple straight segments 223 along the length direction of the insulating substrate 21 and multiple variable-diameter segments 224 located at both ends of the insulating substrate 21, wherein the length direction of the insulating substrate 21 is parallel to the axial direction of the slotless stator coil device 100. When each layer of coil section 22 of the coil structure 20 is energized to generate a magnetic field, the effective magnetic field range is not the entire magnetic field range generated by the coil section 22, but mainly the magnetic field range generated by the multiple straight segments 223. The magnetic field range generated by the multiple variable-diameter segments 224 located at both ends of the insulating substrate 21 has a relatively minor effect on the magnetic induction of the rotor assembly 230 compared to the magnetic induction effect of the magnetic field range generated by the multiple straight segments 223. In each layer of coil section 22 of each coil structure 20 of the slotless stator coil device 100, the lengths of multiple straight sections 223 are all equal. As a result, the range of the effective magnetic field generated when each layer of coil section 22 is energized is increased. When the slotless stator coil device 100 is assembled with the brushless slotless motor 200, the range of the effective magnetic field acting on the rotor assembly 230 of the brushless slotless motor 200 is increased, which effectively improves the output efficiency of the brushless slotless motor 200 and improves the product quality of the brushless slotless motor 200.

[0067] The width of the straight section 223 is greater than, equal to, or less than the width of the variable diameter section 224. To further enhance the magnetic field range generated by the multiple straight sections 223 and its magnetic effect on the rotor assembly 230, this application preferably specifies that the width of the straight section 223 is greater than the width of the variable diameter section 224. This allows for a maximized design of the length of the multiple straight sections 223 on the insulating substrate 21, i.e., increasing the length of the multiple straight sections 223 while reducing the length of the area occupied by the variable diameter section 224 at the end of the insulating substrate 21, thus maximizing the magnetic field range generated by the multiple straight sections 223 and its magnetic effect on the rotor assembly 230.

[0068] Furthermore, although the length of the wider straight section 223 increases, the length of the variable-diameter section 224 decreases accordingly. This further reduces the width of the variable-diameter section 224 compared to the straight section 223, thus maintaining a constant resistance in each layer of coil 22 and preventing an increase in heat generation. This helps ensure the overall thermal performance of the slotless stator coil assembly 100, guarantees its effective operating time, and extends its service life.

[0069] Furthermore, when the line width of the variable diameter section 224 is smaller than the line width of the straight section 223, the height of the multiple variable diameter sections 224 located at both ends of the insulating substrate 21 along the length direction of the insulating substrate 21 can be effectively reduced when spiral wiring is performed in each layer of coil section 22. This is beneficial to reducing the overall length of the coil structure 20 along the axial direction of the slotless stator coil device 100.

[0070] In some embodiments of this application, in the same coil structure 20, the line thickness of any two coil sections 22 may be equal or unequal.

[0071] When the line thickness of any two layers of coil sections 22 in the same coil structure 20 is not equal, in some embodiments of the slotless stator coil device 100 of this application, the line thickness of the multi-layer coil sections 22 of each coil structure 20 gradually increases radially outward from the axis of the cylindrical structure 10. That is, in the multi-layer coil sections 22 of each coil structure 20, the closer to the axis of the cylindrical structure 10, the higher the coil density of the coil section 22. This can effectively enhance the magnetic field generated by the coil section 22 on the rotor assembly 230 of the brushless slotless motor 200, and improve the output power and torque of the brushless slotless motor 200. Furthermore, the design structure of gradually increasing line thickness of the multi-layer coil sections 22 of each coil structure 20 can keep the resistance of each layer of coil section 22 constant, so that the heat generation of each layer of coil section 22 does not increase. This is beneficial to improving the overall thermal performance of the slotless stator coil device 100, ensuring the effective working time of the slotless stator coil device 100, and extending the service life of the slotless stator coil device 100.

[0072] In some embodiments of this application, the cylindrical structure 10 is composed of multiple layers of cylinders nested sequentially, with each layer having an equal number of coil structures 20. Furthermore, along the radial direction of the cylindrical structure 10, the coil structures 20 are arranged opposite each other between adjacent layers. In the multiphase motor of this embodiment, such as a three-phase motor, each layer is formed by three coil structures 20 circumferentially surrounding it, and each phase is composed of multiple coil structures 20 along the radial direction of the cylindrical structure 10. This increases the number of turns in each phase, thereby increasing the generated magnetic field strength and effectively enhancing the magnetic field generated by the coil section 22 on the rotor assembly 230 of the brushless slotless motor 200, thus improving the output power and torque of the brushless slotless motor 200.

[0073] In some embodiments of this application, the cylindrical structure 10 is composed of multiple layers of cylinders nested sequentially, with each layer having an equal number of coil structures 20. Furthermore, the coil structures 20 between any two adjacent layers are circumferentially offset by a predetermined angle in the same direction. Figure 8 and Figure 9 As shown, in some embodiments of this application, the cylindrical structure 10 includes an inner cylinder 11 and an outer cylinder 12 fitted over the inner cylinder 11, i.e., the cylindrical structure 10 is composed of two fitted cylinders. The number of multiple coil structures 20 in the inner cylinder 11 is equal to the number of multiple coil structures 20 in the outer cylinder 12, and adjacent coil structures 20 are connected by a connecting part 13. The multiple coil structures 20 in the inner cylinder 11 and the multiple coil structures 20 in the outer cylinder 12 are staggered circumferentially. For example, if each cylinder is formed by three coil structures 20 surrounding it circumferentially, then the central angle corresponding to each coil structure 20 is 120°. Then, the predetermined rotation angle of the outer cylinder 12 relative to the inner cylinder 11, which is staggered circumferentially, is 60°. Thus, the cylindrical structure 10 formed by the fitted inner cylinder 11 and the outer cylinder 12 actually has six phases.

[0074] In the slotless stator coil device 100 of this application, the number of coil structures 20 in the cylindrical structure 10 can be 3, 6, 9, 12, etc., that is, an integer multiple of 3 coil structures 20. These coil structures 20 are divided into multiple parts, each part is wrapped to form a layer of cylinder, and then multiple layers of cylinders are sequentially nested to form the cylindrical structure 10.

[0075] In some embodiments of this application, such as Figure 6 and Figure 7 As shown, the coil structure 20 has a stepped ridge 23. Along the radial direction of the cylindrical structure 10, the stepped ridge 23 forms a first coil portion 24 and a second coil portion 25 with a height difference in the coil structure 20. Furthermore, the height of the stepped ridge 23 is equal to the thickness of the coil structure 20. Figure 3 and Figure 4 As shown, in two adjacent coil structures 20 along the circumference of the cylindrical structure 10, the first coil portion 24 of one coil structure 20 and the second coil portion 25 of the other coil structure 20 are stacked together, and multiple coil structures 20 are connected end to end to form the cylindrical structure 10. In the multiphase motor of this embodiment, multiple coil structures 20 are interlocked and connected end to end by stepped ribs 23, which actually forms two layers of cylinder, and this makes the cylindrical structure 10 formed by multiple coil structures 20 surrounding each other along the circumference more stable.

[0076] like Figure 1 and Figure 2As shown, in some embodiments of this application, the slotless stator coil device 100 further includes an iron core cylinder 30, which is sleeved and fixed outside the cylindrical structure 10. The iron core cylinder 30 can effectively guide and concentrate the magnetic field to form a magnetic circuit, improve electromagnetic performance, and efficiently generate and transmit electromagnetic energy. The iron core cylinder 30 can also provide mechanical support for the cylindrical structure 10, withstand the electromagnetic and mechanical forces generated during the operation of the brushless slotless motor 200, and prevent the cylindrical structure 10 from being damaged by vibration or impact. Furthermore, the iron core cylinder 30 sleeved and fixed outside the cylindrical structure 10 facilitates heat dissipation of the cylindrical structure 10, effectively reducing the temperature rise during the operation of the brushless slotless motor 200. The iron core cylinder 30 includes multiple magnetic material sheets 31, which are sequentially stacked along the axial direction of the slotless stator coil device 100, and adjacent magnetic material sheets 31 are insulated from each other. The iron core cylinder 30, formed by stacking multiple magnetic material sheets 31, can reduce eddy current losses and hysteresis losses when the coil section 22 of the coil structure 20 is energized to generate a magnetic field. The magnetic material sheets 31 include, but are not limited to, silicon steel sheets, amorphous material sheets, and iron sheets.

[0077] According to another aspect of this application, a brushless slotless motor 200 is provided. For example... Figures 10 to 15 As shown, the brushless slotless motor 200 includes a housing 210, a rotor assembly 230, two bearings 220, and a slotless stator coil assembly 100 as described above. The housing 210 includes a housing body 211 and an end cover 212. The end cover 212 closes to one end of the housing body 211 to form an assembly space 213. The slotless stator coil assembly 100 is accommodated in the assembly space 213. Wires leading from the positive and negative pads 41 and 42 of each coil structure 20 exit through the outlet 214 of the housing 210. These wires are used for electrical connection to the electronic commutation mechanism. Furthermore, as... Figures 13 to 15 As shown, two bearings 220 are mounted on the housing 210. The two bearings 220 are located at both ends of the slotless stator coil assembly 100, that is, one bearing 220 is mounted on the end cover 212, and the other bearing 220 is mounted on the other end of the housing body 211 away from the end cover. Figures 13 to 15As shown, the rotor assembly 230 includes a spindle 231 and a permanent magnet 232. The permanent magnet 232 is fixedly sleeved on the spindle 231 and rotatably passes through the slotless stator coil device 100. Both ends of the spindle 231 are respectively mounted on two bearings 220. At least one end of the spindle 231 serves as a motor output end, which can be the end of the spindle 231 that protrudes from the housing 210; alternatively, the motor output end can be located within the housing 210. One end of the spindle 231 protrudes from the end of the housing body 211 away from the end cover 212 as a single output end of the motor, in which case the motor is a single-start motor; or, one end of the spindle 231 protrudes from the end of the housing body 211 away from the end cover 212 as one output end, and the other end of the spindle 231 protrudes from the end cover 212 as the other output end, in which case the motor is a dual-start motor.

[0078] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A slotless stator coil device, characterized in that, It includes multiple coil structures, which are arranged in a cylindrical shape around each other in the circumferential direction; Each of the coil structures includes an insulating substrate and a multilayer coil portion stacked on the insulating substrate. Each layer of the coil portion has a first connection end and a second connection end. Each layer of the coil portion is spirally arranged by at least one wire. The first connection end is the outer spiral end of the coil portion, and the second connection end is the inner spiral end of the coil portion. The spiral directions of adjacent two layers of the coil portion from the first connection end to the second connection end are opposite. In the radial direction outward from the axis of the slotless stator coil device along the cylindrical structure, the first connection end of the first layer of the coil section is set as one of the positive and negative terminals of the coil structure, and the first connection end or the second connection end of the outermost layer of the coil section is set as the other of the positive and negative terminals of the coil structure. Between two adjacent layers of the coil section, the two first connection ends or the two second connection ends are electrically connected, so that the multi-layer coil sections are connected in series.

2. The slotless stator coil device according to claim 1, characterized in that, In each of the coil structures, along the radial direction of the cylindrical structure, the projections of the first connecting end and the second connecting end of each layer of the coil portion on the insulating substrate coincide.

3. The slotless stator coil device according to claim 1, characterized in that, The at least one line of the coil section in each layer is formed by additive manufacturing process, and the cross-section of the at least one line is rectangular, trapezoidal or arc-shaped at the top.

4. The slotless stator coil device according to claim 1, characterized in that, Each of the coil structures includes n layers of the coil section, and n ≥ 2m, where m is a positive integer.

5. The slotless stator coil device according to claim 1, characterized in that, Along the axial direction of the slotless stator coil assembly, the shape of each coil turn in each layer of the coil section is rectangular, rhomboid, polygonal, racetrack-shaped, or olive-shaped.

6. The slotless stator coil device according to claim 5, characterized in that, The width of at least one line in the coil section of each layer is variable in the routing direction, and in the same coil structure, the number of coil turns of any two coil sections is equal or unequal.

7. The slotless stator coil device according to claim 6, characterized in that, When the shape of each coil turn in the coil section of each layer is racetrack-shaped, the insulating substrate is square. Each coil section includes multiple straight segments along the length direction of the insulating substrate and multiple variable diameter segments located at both ends of the insulating substrate. The lengths of the multiple straight segments are all equal, and the line width of the straight segments is greater than, equal to or less than the line width of the variable diameter segments.

8. The slotless stator coil device according to claim 5, characterized in that, In the same coil structure, the thickness of at least one line in any two layers of the coil section is equal or unequal.

9. The slotless stator coil device according to claim 8, characterized in that, Along the radial direction outward from the axis of the cylindrical structure, the circuit thickness of the multilayer coil portion of each coil structure gradually increases.

10. The slotless stator coil device according to claim 1, characterized in that, The slotless stator coil device also includes an iron core cylinder, which is sleeved and fixed outside the cylindrical structure, and the iron core cylinder is formed by stacking multiple annular magnetic material sheets.

11. The slotless stator coil device according to any one of claims 1-10, characterized in that, The cylindrical structure is composed of multiple layers of cylinders nested together, and the number of multiple coil structures in each layer of the cylinder is equal; Along the radial direction of the cylindrical structure, multiple coil structures are arranged opposite each other between two adjacent layers of the cylinder, or multiple coil structures between any two adjacent layers of the cylinder are circumferentially offset by a predetermined angle in the same direction.

12. The slotless stator coil device according to any one of claims 1-10, characterized in that, The coil structure has stepped edges. Along the radial direction of the cylindrical structure, the stepped edges form a first coil portion and a second coil portion with a height difference. The height of the stepped edges is equal to the thickness of the coil structure. In two adjacent coil structures along the circumference of the cylindrical structure, the first coil portion of one coil structure is stacked with the second coil portion of the other coil structure. Multiple coil structures are connected end to end to form the cylindrical structure.

13. A brushless, slotless motor, characterized in that, include: The casing has assembly space; The slotless stator coil assembly as described in any one of claims 1-12, wherein the slotless stator coil assembly is accommodated in the assembly space; Two bearings are mounted on the housing, and the two bearings are respectively located at both ends of the slotless stator coil assembly; The rotor assembly is rotatably mounted on the slotless stator coil assembly, and the two ends of the rotor assembly are respectively mounted on the two bearings.

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