PCB stator and axial flux motor

Abstract

The application relates to a PCB stator and an axial flux motor, wherein the PCB stator comprises a core assembly and a PCB board, the core assembly comprises a magnetic yoke plate and a plurality of cores which are distributed on one side surface of the magnetic yoke plate in a circumferential direction, and a groove part is formed between two adjacent cores; a first end of the groove part is connected with one of the cores, a second end of the groove part is connected with another core, and the lengths of the first end and the second end are different in a radial direction; the PCB board comprises a first substrate provided with a plurality of through holes and a coil arranged on a surface of the first substrate, wherein the coil is formed by a conductive circuit on the first substrate, the through holes are the same in number as the cores and are one-to-one corresponding; the magnetic yoke plate is arranged on one side of the PCB board, and the cores are inserted into the through holes. The application adopts an inclined groove structure, when the PCB stator and the rotor work together, permanent magnets on the rotor pass through two ends with different lengths of the groove part in sequence, the spatial phase of the cogging torque can be offset, the cogging torque is reduced, and the overall working performance and operation efficiency are improved.

Description

Technical Field

[0001] This invention relates to the field of axial flux motor technology, and more particularly to a PCB stator and an axial flux motor. Background Technology

[0002] Axial flux motors have been widely used in lightweight drive applications in recent years due to their high power density and compact structure. Among them, the stator scheme using printed circuit boards (PCBs) as the winding carrier (i.e., PCB stator) has advantages such as high winding accuracy, reliable interlayer insulation, and ease of multilayer integration. However, when a PCB stator is used in conjunction with a traditional toroidal laminated iron core, the inherent cogging structure of the iron core and the rotor permanent magnet generate periodic magnetic pull, inducing significant cogging torque, leading to the following situation:

[0003] (1) When running at low speed, the torque pulsation is large, which causes mechanical vibration and high-frequency noise; (2) It deteriorates compliant control performance and reduces position repeatability in robot joint applications; (3) Under pump operating conditions, the bearing vibration is aggravated, and the life of the seals and impeller is shortened; (4) The aircraft’s attitude fine-tuning is unstable during the hovering phase, which affects flight safety.

[0004] Currently, mainstream technologies for reducing cogging torque include fractional-slot windings, magnetic pole offset, unequal air gaps, and skewed slot designs. However, these technologies face significant compatibility bottlenecks in axial flux PCB stator motors, such as: Fractional slot windings are limited by the accuracy of PCB wiring grids and the number of layers, making it difficult to achieve ideal harmonic suppression; Magnetic pole misalignment disrupts the axial magnetic field symmetry, introducing additional torque ripple and eddy current losses. While skewed slot technology is mature in radial motors (such as skewed rotor poles or skewed stator slots), in axial flux structures, the stator core is thin and ring-shaped with a short axial dimension (usually <8mm), and it needs to be strictly conformally fitted to the planar PCB windings. Traditional skewed slot processing methods (such as integral milling of the skew surface) will lead to misalignment between iron cores, a decrease in the stacking coefficient, and local stress concentration, which cannot meet the stringent requirements of PCB stators for the flatness of the iron core end face (≤0.02mm) and the consistency of the slot shape (±0.05°).

[0005] Therefore, there is a need for a PCB stator and axial flux motor that can achieve integrated assembly of PCB windings and iron core, thereby reducing cogging torque. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention provides a PCB stator and an axial flux motor.

[0007] The technical solution of this invention is as follows: A PCB stator, comprising: A core assembly includes a magnetic yoke plate and a plurality of cores distributed circumferentially on one side surface of the magnetic yoke plate, with a groove formed between two adjacent cores; a first end of the groove is connected to one of the cores, and a second end of the groove is connected to the other core; the lengths of the first end and the second end are different in the radial direction. The PCB board includes a first substrate with multiple through holes and a coil disposed on the surface of the first substrate, wherein the coil is formed by conductive lines on the first substrate, and the number of through holes is the same as that of the iron core and they correspond one-to-one. The magnetic yoke is located on one side of the PCB board, and the iron core is inserted into the through hole.

[0008] As a further improvement of the present invention, the core includes multiple laminations that are sequentially stacked on the magnetic yoke plate, and the multiple laminations are sequentially and alternately stacked in a step-by-step manner along the circumferential direction, with an insulating layer provided between adjacent laminations.

[0009] As a further improvement of the present invention, with the center of the magnetic yoke plate as the reference point, the step deflection angle between two adjacent stacked plates is θ. .

[0010] As a further improvement of the present invention, the magnetic yoke plate includes a second substrate in the shape of an annulus and a plurality of extensions extending outward along the outer edge of the second substrate, and the stacked sheets are in the shape of a fan-shaped ring; The projections of the two ends of the laminate along the radial direction onto the axial direction coincide with the inner edge and outer edge of the second substrate, respectively. The second substrate located between two adjacent iron cores and one of the extensions together form a groove.

[0011] As a further improvement of the present invention, the extension lines of both ends of the stacked sheets in the circumferential direction all pass through the center of the second substrate.

[0012] As a further improvement of the present invention, the projection of the end of the extension away from the second substrate in the axial direction is a first straight line segment, and the first straight line segment extends outward along the parallel component direction of the circumferential stepping direction of the laminate.

[0013] As a further improvement of the present invention, the projection of the end of the groove portion that connects to the core in the circumferential stepping direction of the laminate in the axial direction forms a second straight line segment, and the included angle between the first straight line segment and the second straight line segment is α. .

[0014] As a further improvement of the present invention, the first substrate includes a plurality of stacked third substrates, and the coil includes an A-phase coil, a B-phase coil, and a C-phase coil, wherein an A-phase coil is provided on one of the third substrates, a B-phase coil is provided on one of the third substrates, and a C-phase coil is provided on one of the third substrates.

[0015] As a further improvement of the present invention, the core comprises multiple laminations sequentially stacked on the yoke plate, wherein the pitch of the coil of each phase matches the circumferential width of the individual laminations projected in the axial direction.

[0016] As a further improvement of the present invention, in the circumferential direction, the width of the groove is 30%-40% of the width of the stacked pieces.

[0017] An axial flux motor includes a PCB stator, a rotor, and a shaft as described above, wherein the PCB stator and the rotor are arranged opposite to each other around the shaft.

[0018] According to the above-described solution, the beneficial effects of this invention are as follows: 1. The present invention adopts a design with different lengths at both ends of the groove to realize the inclined slot structure of the iron core assembly. When the PCB stator and rotor work together, the permanent magnet on the rotor passes through the two ends of the groove with different lengths one after the other, which can realize the spatial phase cancellation of the cogging torque, reduce the cogging torque, improve the overall working performance and operating efficiency, and reduce energy consumption and noise. 2. In this invention, the magnetic yoke plate abuts against the PCB board, and the iron core is inserted into the PCB board, realizing high-precision integrated assembly between the PCB board and the iron core assembly. The structure is feasible and the process is compatible. Without sacrificing power density and efficiency, it can effectively reduce the peak value of cogging torque and reduce low-speed jitter, meeting the stringent requirements of ultra-low torque pulsation in fields such as robotics, automobiles, and aviation. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the magnetic yoke plate of the present invention; Figure 2 yes Figure 1 A magnified view of a section at point A in the middle; Figure 3 yes Figure 2 Schematic diagram of the division of the central groove; Figure 4 This is a schematic diagram of the assembly of the magnetic yoke plate and the PCB board at the first angle of the present invention; Figure 5 yes Figure 4 A magnified view of a section at point B in the middle; Figure 6 This is a schematic diagram of the assembly of the magnetic yoke plate and the PCB board at the second angle of the present invention; Figure 7 This is a schematic diagram of the stacking of the laminates of the present invention; Figure 8 This is a schematic diagram of the stacking step angle of the present invention; Figure 9 This is a comparison diagram of the cogging torque between the inclined groove scheme of the present invention and the straight groove scheme of the prior art.

[0020] In the figure: 1. Magnetic yoke plate; 11. Second substrate; 12. Extension; 13. First straight segment; 2. Iron core; 21. Laminated plate; 3. Groove; 31. Second straight segment; 41. Through hole; 42. First substrate. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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 the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0024] See Figure 1-6 The present invention provides a PCB stator, including a detachably configured core assembly and a PCB board; The core assembly includes a magnetic yoke plate 1 and multiple cores 2 distributed circumferentially on one side surface of the magnetic yoke plate 1. A groove 3 is formed between two adjacent cores 2, that is, the cores 2 divide the magnetic yoke plate 1 into multiple grooves 3. The cores 2 and the grooves 3 are spaced apart. Preferably, the cores 2 are evenly distributed, and the cores 2 protrude from the surface of the magnetic yoke plate 1 and serve as stator teeth of the PCB stator. The grooves 3 serve as stator slots of the PCB stator. The first end of the groove 3 is connected to one of the cores 2, and the second end of the groove 3 is connected to another core 2. In the radial direction, the lengths of the first end and the second end are different, making the groove 3 asymmetrical and inclined to one side, presenting a slanted groove structure. The PCB board includes a first substrate 42 with multiple through holes 41 and a coil disposed on the surface of the first substrate 42. The coil is formed by conductive lines on the first substrate 42. The number of through holes 41 is the same as that of the iron core 2 and they correspond one-to-one. Optionally, the PCB board uses FR-4 substrate with a high glass transition temperature (TG>170℃). During assembly, the magnetic yoke 1 is placed on one side of the PCB board, and the magnetic yoke 1 abuts against the PCB board. The iron core 2 is inserted into the through hole 41. Optionally, the height of the iron core 2 is greater than the thickness of the PCB board. That is, when the iron core 2 is inserted into the through hole 41, the end of the iron core 2 away from the magnetic yoke 1 passes through the through hole 41 and is exposed.

[0025] This invention employs a design where the two ends of the groove 3 have different lengths to achieve a slanted slot structure for the iron core assembly. When the PCB stator and rotor work together, the permanent magnets on the rotor pass through the two ends of the groove 3 with different lengths, which can achieve spatial phase cancellation of the cogging torque, reduce the cogging torque, improve the overall working performance and operating efficiency, and reduce energy consumption and noise. In addition, the magnetic yoke plate 1 abuts against the PCB board, and the iron core 2 is inserted into the PCB board, realizing high-precision integrated assembly between the PCB board and the iron core assembly. The structure is feasible and the process is compatible. Without sacrificing power density and efficiency, it can effectively reduce the peak value of cogging torque and reduce low-speed jitter, meeting the stringent requirements for ultra-low torque pulsation in fields such as robotics, automobiles, and aerospace.

[0026] See Figure 7 and Figure 8As one embodiment of the present invention, the iron core 2 includes multiple laminations 21 sequentially stacked on the magnetic yoke plate 1. The multiple laminations 21 are sequentially and alternately stacked in the circumferential direction, that is, each lamination 21 is inclined at a uniform mechanical angle in the circumferential direction to form a spiral groove structure. The angle and distance of the stagger between adjacent laminations 21 are the same. The projection of the iron core 2 in the axial direction is smaller than the size of the through hole 41 on the PCB board, so that the iron core 2 can be smoothly inserted into the through hole 41 when the iron core assembly and the PCB board are assembled. Optionally, the core 2 is made of 24 laminations 21 stacked together. The laminations 21 are stacked in a stepwise manner along the first direction. The laminations 21 are made of DW310-35 high-grade cold-rolled non-oriented silicon steel sheets. The total thickness after stacking is 20±0.2mm. An insulating layer is provided between two adjacent laminations 21. The insulating layer can be an insulating film, or an insulating coating can be sprayed on the surface of the laminations 21, or other insulating measures can be adopted. The resistance of the insulating layer is greater than 100MΩ, and the insulating layer must withstand 1500VAC for 60 seconds without breakdown.

[0027] In one embodiment of the present invention, with the center of the magnetic yoke plate 1 as the reference point, the step deflection angle between two adjacent stacked plates 21 is θ. The step deflection angle θ satisfies: ; Where Z is the number of stator teeth and 2P is the number of rotor poles. Preferably, the step deflection angle is 3°, which has the best suppression effect and the best process tolerance under the condition of short axial magnetic flux circuit.

[0028] As an embodiment of the present invention, the magnetic yoke plate 1 includes a second base plate 11 in the shape of a ring and a plurality of extension portions 12 extending outward along the outer edge of the second base plate 11. The extension portions 12 are respectively disposed on the second base plate 11 between two adjacent iron cores 2. Optionally, the outer diameter of the second base plate 11 is 150 mm and the inner diameter is 80 mm. The stacked pieces 21 are fan-shaped rings, that is, the projection of the two ends of the stacked pieces 21 in the radial direction in the axial direction is an arc, and the projection of the two ends of the stacked pieces 21 in the circumferential direction in the axial direction is a straight line. Optionally, each stacked piece 21 corresponds to a 15° central angle. Preferably, the projections of the two ends of the stacked plate 21 in the radial direction onto the axial direction coincide with the inner edge and outer edge of the second substrate 11, respectively. That is, the projection of the stacked plate 21 in the axial direction falls completely on the second substrate 11, so that the size of the stacked plate 21 in the radial direction is as large as possible and does not exceed the range of the second substrate 11. This can improve the magnetic flux and facilitate the installation and fixation of the stacked plate 21.

[0029] The second substrate 11 located between two adjacent iron cores 2 and an extension 12 together form a groove 3. The groove 3 adopts a combination design of part of the second substrate 11 and extension 12, which can further ensure that the two ends of the groove 3 are different in the circumferential direction, satisfy the inclined groove design, realize the spatial phase cancellation of the cogging torque, and reduce the cogging torque.

[0030] In one embodiment of the present invention, the extension lines of both ends of the stacked sheet 21 in the circumferential direction both pass through the center of the second substrate 11, that is, the stacked sheet 21 has a symmetrical structure. Of course, the line connecting the midpoints of the two ends of the stacked sheet 21 in the radial direction also necessarily passes through the center of the second substrate 11. Figure 7 As shown, the step deflection angle θ between two adjacent stacked sheets 21 is the angle between the lines connecting the midpoints of the two adjacent stacked sheets 21. Based on the symmetrical structure of the laminate 21, the second substrate 11 located between two adjacent iron cores is also a symmetrical structure. Therefore, the lengths of the two ends of this part along the circumferential direction are the same. However, the extension 12 adopts an asymmetrical structure, which makes the lengths of the two ends of the groove 3 along the circumferential direction different, thereby realizing that the groove 3 is a slanted groove structure.

[0031] Of course, the stack 21 can also be designed as an asymmetrical structure according to specific usage requirements, that is, at least one of the extension lines of the two ends of the stack 21 in the circumferential direction does not pass through the center of the second substrate 11.

[0032] As an embodiment of the present invention, taking the stacked sheets 21 as an example of stepping and interleaving along a first direction, specifically, the first direction can be a counterclockwise direction or a clockwise direction. The projection of the end of the extension 12 away from the second substrate 11 in the axial direction is a first straight line segment 13. The first straight line segment 13 extends outward along the parallel component direction of the circumferential stepping direction of the stacked sheets 21 (i.e., the first direction). That is, the extension 12 gradually extends away from the second substrate 11 along the first direction. Assuming that the two ends of the groove 3 along the first direction are the X end and the Y end, the length of the X end is less than the length of the Y end; preferably, the first straight line segment 13 coincides with the tangent of the second substrate 11, which facilitates the manufacturing of the extension 12 and reduces the process difficulty and cost.

[0033] In one embodiment of the present invention, the projection of the end of the groove portion 3 that connects to the core 2 in the circumferential stepping direction (i.e., the first direction) of the laminate 21 onto the core 2 in the axial direction forms a second straight line segment 31. That is, the projection of the Y end in the axial direction is the second straight line segment 31, and the included angle between the first straight line segment 13 and the second straight line segment 31 is α. Preferably, α is 75°, that is, the angle between the perpendicular line of the first straight line segment 13 and the second straight line segment 31 is 15°.

[0034] As an embodiment of the present invention, the first substrate 42 includes a plurality of stacked third substrates, which are all insulated from each other. Optionally, the third substrate is a rigid FR-4 substrate. The coil includes an A-phase coil, a B-phase coil, and a C-phase coil. One third substrate is provided with an A-phase coil, one third substrate is provided with a B-phase coil, and one third substrate is provided with a C-phase coil. That is, the A-phase coil, B-phase coil, and C-phase coil are all isolated from each other and there is no electrical interference between them. At least one other third substrate is provided with grounding and power supply.

[0035] As an embodiment of the present invention, the core 2 includes multiple laminations 21 stacked sequentially on the yoke plate 1. The pitch of the coil of each phase is matched with the circumferential width of the projection of a single lamination 21 in the axial direction. That is, along the axial direction, the coils corresponding to the laminations 21 all fall on the axial projection of the laminations 21 and do not exceed the axial projection range of the laminations 21. The conductive lines on the PCB are laser-etched and wired strictly according to the direction of the groove 3 to realize the physical correspondence and magnetic coupling between the laminations 21 and the coils.

[0036] As an embodiment of the present invention, in the circumferential direction, the width of the groove portion 3 is 30%-40% of the width of the lamination 21. By precisely controlling the dimensional relationship between the stator teeth and the stator slots, the abrupt change in air gap magnetic permeability is limited, and the tooth harmonic magnetomotive force is further weakened.

[0037] This invention provides an axial flux motor, including a PCB stator, a rotor, and a shaft as described above. The PCB stator and rotor are arranged opposite to each other around the shaft. Optionally, the rotor is a surface-mount permanent magnet structure with a magnetic pole arc coefficient ≥0.85. After cooperating with the skewed slot stator, the fundamental phase difference of the cogging torque generated at each tooth position is θ×Z, forming an approximately uniformly distributed phasor sum, and the total cogging torque approaches zero.

[0038] The following is a specific implementation parameter: The core 2 is composed of 24 laminations 21, which are made of 0.2mm thick 35WN270 non-oriented silicon steel. Each lamination 21 corresponds to a 15° central angle. The stator tooth count Z is 12, and the rotor pole count 2P is 10. The inclined slots are machined with a 3° angle, meaning that the tooth centerline of the i-th lamination 21 is rotated (i-1)×3° relative to the first lamination 21. All laminations 21 are vacuum-pressed and cured with epoxy resin, with an end face flatness of 0.018mm. The PCB board is a six-layer board, with three layers for the three-phase windings and the other three layers for grounding or power supply. The line width of the conductive lines on the PCB board is 0.3mm and the line spacing is 0.2mm. The A / B / C three-phase windings are etched according to the helical tooth projection trajectory. After assembly, the air gap height is 0.8mm. The PCB board and iron core assembly are radially locked with four M3 stainless steel screws. Simulation tests show that the cogging torque is 0.0137Nm, which meets the market demand.

[0039] See Figure 9 The figure shows a comparison of the cogging torque between the inclined slot core structure of the present invention and the conventional straight slot core structure. As can be seen from the figure, the inclined slot core mechanism of the present invention can greatly reduce the cogging torque, thereby improving the overall working performance and operating efficiency, and reducing energy consumption and noise.

[0040] Although this embodiment uses a PCB board as the winding carrier for illustration, those skilled in the art should understand that the stepper stacked skewed core assembly provided by the present invention is also applicable to axial flux motors using flat copper wire windings, concentrated windings, or flexible printed circuits (FPCs), and these alternatives are all within the scope of the present invention.

[0041] In summary, this invention provides a PCB stator and an axial flux motor. The design of the two ends of the groove 3 having different lengths achieves a slanted slot structure for the core assembly. When the PCB stator and rotor work together, the permanent magnets on the rotor pass successively through the two ends of the groove 3 with different lengths, achieving spatial phase cancellation of cogging torque, reducing cogging torque, improving overall performance and operating efficiency, and reducing energy consumption and noise. Furthermore, the yoke plate 1 abuts against the PCB board, and the core 2 is inserted into the PCB board, achieving high-precision integrated assembly between the PCB board and the core assembly. The structure is feasible, the process is compatible, and it does not sacrifice… Under the premise of power density and efficiency, it can effectively reduce the peak value of cogging torque and reduce low-speed jitter, meeting the stringent requirements of ultra-low torque pulsation in fields such as robotics, automobiles, and aerospace; the radial dimension of the lamination 21 is as large as possible without exceeding the range of the second substrate 11, which can improve the magnetic flux and facilitate the installation and fixation of the lamination 21; the first straight segment 13 coincides with the tangent of the second substrate 11, which facilitates the manufacturing of the extension 12 and reduces the process difficulty and cost; the pitch of the coil of each phase is matched with the circumferential width of the axial projection of a single lamination 21, realizing the one-to-one physical correspondence and magnetic circuit coupling between the lamination 21 and the coil.

[0042] It should be emphasized that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A PCB stator, characterized in that, include: The core assembly includes a magnetic yoke plate (1) and a plurality of cores (2) distributed circumferentially on one side surface of the magnetic yoke plate (1), with a groove (3) formed between two adjacent cores (2); the first end of the groove (3) is connected to one of the cores (2), and the second end of the groove (3) is connected to the other core (2), and the lengths of the first end and the second end are different in the radial direction; The PCB board includes a first substrate (42) having a plurality of through holes (41) and a coil disposed on the surface of the first substrate (42), wherein the coil is formed by conductive lines on the first substrate (42), and the number of through holes (41) is the same as that of the iron core (2) and they correspond one-to-one. The magnetic yoke plate (1) is disposed on one side of the PCB board, and the iron core (2) is inserted into the through hole (41).

2. The PCB stator according to claim 1, characterized in that, The core (2) includes multiple laminations (21) stacked sequentially on the magnetic yoke plate (1), and the multiple laminations (21) are stacked in a staggered manner in the circumferential direction, with an insulating layer between adjacent laminations (21).

3. The PCB stator according to claim 2, characterized in that, With the center of the magnetic yoke plate (1) as the reference point, the step deflection angle between two adjacent stacked plates (21) is θ. .

4. The PCB stator according to claim 2, characterized in that, The magnetic yoke plate (1) includes a second substrate (11) in the shape of a ring and a plurality of extensions (12) extending outward along the outer edge of the second substrate (11), and the stacked plate (21) is in the shape of a fan ring; The projections of the two ends of the laminate (21) in the radial direction onto the axial direction coincide with the inner and outer edges of the second substrate (11), respectively. The second substrate (11) located between two adjacent iron cores (2) together with an extension (12) forms a groove (3).

5. The PCB stator according to claim 4, characterized in that, The extension lines of both ends of the stack (21) along the circumferential direction all pass through the center of the second substrate (11).

6. The PCB stator according to claim 4, characterized in that, The projection of the end of the extension (12) away from the second substrate (11) in the axial direction is a first straight line segment (13), which extends outward along the parallel component direction of the circumferential stepping direction of the stack (21).

7. The PCB stator according to claim 6, characterized in that, The groove portion (3) is projected in the axial direction by the end of the lamination (21) that connects to the core (2) in the circumferential stepping direction as a second straight line segment (31), and the angle between the first straight line segment (13) and the second straight line segment (31) is α. .

8. The PCB stator according to claim 1, characterized in that, The first substrate (42) includes a plurality of stacked third substrates, and the coil includes an A-phase coil, a B-phase coil, and a C-phase coil, wherein an A-phase coil is provided on one of the third substrates, a B-phase coil is provided on one of the third substrates, and a C-phase coil is provided on one of the third substrates.

9. The PCB stator according to claim 8, characterized in that, The core (2) comprises multiple laminations (21) stacked sequentially on the yoke plate (1), and the pitch of the coil of each phase is matched with the circumferential width of the individual laminations (21) projected in the axial direction.

10. The PCB stator according to claim 2, characterized in that, In the circumferential direction, the width of the groove (3) is 30%-40% of the width of the stack (21).

11. An axial flux motor, characterized in that, It includes a PCB stator, a rotor, and a rotating shaft as described in any one of claims 1-10, wherein the PCB stator and the rotor are arranged opposite to each other around the rotating shaft.

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