Three-phase high power density PCB stator winding structure, motor and micro fan thereof

Abstract

This utility model discloses a three-phase high power density PCB stator winding structure and its motor and miniature fan. Each layer of the PCB coil board in the three-phase high power density PCB stator winding structure is symmetrically divided into six coil regions, each with a 2D printed coil forming six windings. Windings in the same numbered coil region on different layers are connected in series via internal or external interlayer vias to form windings U1, V1, W1, U2, V2, and W2. Two windings 180° apart mechanically constitute one phase. Since the windings are roughly the same shape, the problem of large electromagnetic torque fluctuations is effectively solved, improving the motor's operational stability. Furthermore, the 2D printed coils are spirally wound, resulting in a compact layout, high coil density, and effectively improved area utilization and increased power. Applying this three-phase high power density PCB stator winding structure to motors or miniature fans makes the overall structure more compact and thinner.

Description

Technical Field

[0001] This utility model relates to the field of stator technology, specifically to a three-phase high power density PCB stator winding structure and its motor and micro fan. Background Technology

[0002] As smart devices such as laptops, tablets, and mobile phones become increasingly thinner and lighter, the fans used for cooling these devices are also becoming thinner. Further reducing the size of these miniature fans presents a significant challenge to the fan industry. One solution is to use miniature fans with 2D printed coils.

[0003] The existing PCB coil boards for 2D printed coils mostly adopt a non-circular structure, that is, there is a protruding structure on the outer periphery, which can only be embedded with the base. Once the protruding structure protrudes on the base, it will interfere with the rotor. Moreover, the coil area utilization rate on the PCB coil board is relatively low, and even the positions and shapes of the individual coils are not symmetrical, resulting in large fluctuations in electromagnetic torque. Utility Model Content

[0004] To address the aforementioned shortcomings, the purpose of this utility model is to provide a three-phase high power density PCB stator winding structure with a reasonable structural design, as well as its motor and micro fan.

[0005] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0006] A three-phase high power density PCB stator winding structure includes a PCB coil board with a circular overall outline. The PCB coil board has six layers, each layer being symmetrically divided into six coil regions around its center. Each of the six coil regions has a roughly identical, spirally wound 2D printed coil, forming six windings. The 2D printed coils are printed in a spiral pattern, and the spacing between lines within the same 2D printed coil is the same as the spacing between adjacent 2D printed coils on the same layer. The 2D printed coils in each layer are connected through internal or external interlayer vias. The spiral coil printing method fully utilizes the space of the PCB coil board, improves the coil area utilization rate, increases the effective conductor length, and thus improves the electromagnetic performance and power density of the motor. The uniform spacing between coils in each layer and the orderly series connection between layers maximize the winding density, thereby improving motor efficiency. Windings of the same numbered coil region but different layers are connected in series through internal or external interlayer vias to form windings U1, V1, W1, U2, V2, and W2. Windings U1 and U2 are 180° apart mechanically and connected in series to form the U-phase winding; windings V1 and V2 are 180° apart mechanically and connected in series to form the V-phase winding; windings W1 and W2 are 180° apart mechanically and connected in series to form the W-phase winding. The combination of the U-phase, V-phase, and W-phase windings constitutes the winding structure of a three-phase motor.

[0007] In a preferred embodiment of this utility model, the winding U1 is formed by sequentially connecting 2D printed coils in the first coil region of the first layer, second layer, third layer, fifth layer, sixth layer and fourth layer of the PCB coil board; the winding U2 is formed by sequentially connecting 2D printed coils in the fourth coil region of the fourth layer, sixth layer, fifth layer, third layer, first layer and second layer of the PCB coil board; the winding U1 and the winding U2 are connected in series on the fourth layer of the PCB coil board to form a U-phase winding.

[0008] The winding V1 is formed by connecting 2D printed coils in series in the second coil region of the first, second, third, fourth, sixth and fifth layers of the PCB coil board; the winding V2 is formed by connecting 2D printed coils in series in the fifth coil region of the fifth, sixth, fourth, third, first and second layers of the PCB coil board; the winding V1 and the winding V2 are connected in series on the fifth layer of the PCB coil board to form a V-phase winding.

[0009] The winding W1 is formed by connecting 2D printed coils in series in the third coil region of the first, second, third, fifth, fourth and sixth layers of the PCB coil board; the winding W2 is formed by connecting 2D printed coils in series in the sixth coil region of the sixth, fourth, fifth, third, first and second layers of the PCB coil board; the windings W1 and W2 are connected in series on the sixth layer of the PCB coil board to form a W-phase winding.

[0010] As a preferred embodiment of this utility model, the outer contour of the 2D printed coil is approximately in the shape of an isosceles trapezoid, wherein the upper base is close to the center of the PCB coil board, the upper base and the two waist sides are straight lines, and the lower base is an arc, the center of the arc does not coincide with the center of the PCB coil board, so as to generate the necessary torque.

[0011] In a preferred embodiment of this invention, the connection between the upper bottom edge and the two waist edges uses an outer rounded corner transition, and the connection between the lower bottom edge and the two waist edges uses an inner rounded corner transition. The positions between the outer rounded corners of two adjacent 2D printed coils form six outer triangular areas on the PCB coil board, and the positions between the inner rounded corners of two adjacent 2D printed coils form six inner triangular areas on the PCB coil board. The rounded corner transition of the 2D printed coil corners provides reasonable space for subsequent pad and via placement, facilitating circuit connection and layout, resulting in high space utilization and improved structural compactness.

[0012] In a preferred embodiment of this invention, the PCB coil board has at least four pads distributed in the outer triangular area; the external interlayer vias are located in the inner triangular area, and the internal interlayer vias are located at the geometric center of the 2D printed coil. Using pads as connection points, and arranging them in the outer triangular area, fully utilizes space, saves PCB space, and avoids the pads occupying extra space and affecting the winding layout and overall compactness of the motor structure. It also facilitates manufacturing and subsequent wiring operations. Interlayer connections are achieved through internal and external interlayer vias, eliminating the wiring process and making the multi-layer winding structure more compact and rational, which is beneficial for further reducing motor size and increasing power density.

[0013] In a preferred embodiment of this invention, the internal or external interlayer via is connected to only two of the 2D printed coils. This connection method improves the reliability and accuracy of the connection, reduces the complexity and potential failure points caused by connecting too many coils through the via, and helps to improve the yield rate of motor production and long-term operational stability.

[0014] An electric motor comprising the aforementioned three-phase high power density PCB stator winding structure.

[0015] A miniature fan comprising the aforementioned three-phase high power density PCB stator winding structure.

[0016] The beneficial effects of this utility model are as follows: The three-phase high power density PCB stator winding structure of this utility model is reasonably designed. The PCB coil board adopts a circular shape to avoid interference with other components, which facilitates structural design and improves space utilization. Each layer of the PCB coil board is symmetrically divided into six coil areas. Each of the six coil areas is printed with a 2D printed coil with a roughly the same shape and spiral winding, forming six windings. The windings of the same numbered coil area on different layers are connected in series through internal or external interlayer vias to form windings U1, V1, W1, U2, V2, and W2. Two windings 180° apart mechanically form a phase, resulting in U-phase winding, V-phase winding, and W-phase winding. Since the shapes of each winding are roughly the same, the problem of large electromagnetic torque fluctuation is effectively solved, improving the stability of motor operation. Moreover, the 2D printed coils in the windings are spirally wound, with a compact layout and high coil density, effectively improving area utilization and increasing power. Applying a three-phase high power density PCB stator winding structure to motors or micro fans can effectively optimize the overall structural layout, making the motors or micro fans more compact and thinner.

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this utility model.

[0019] Figure 2 This is a schematic diagram of the first layer structure of Embodiment 1 of this utility model.

[0020] Figure 3 This is a schematic diagram of the second layer structure of Embodiment 1 of this utility model.

[0021] Figure 4 This is a schematic diagram of the third layer structure of Embodiment 1 of this utility model.

[0022] Figure 5 This is a schematic diagram of the fourth layer structure of Embodiment 1 of this utility model.

[0023] Figure 6 This is a schematic diagram of the fifth layer structure of Embodiment 1 of this utility model.

[0024] Figure 7 This is a schematic diagram of the sixth layer structure of Embodiment 1 of this utility model.

[0025] Figure 8This is a cross-sectional structural diagram of Embodiment 2 of this utility model.

[0026] Figure 9 This is an exploded structural diagram of Embodiment 2 of this utility model.

[0027] Figure 10 This is a cross-sectional structural diagram of Embodiment 3 of this utility model.

[0028] Figure 11 This is an exploded structural diagram of Embodiment 3 of this utility model.

[0029] Figure 12 This is a torque waveform diagram of the 6-slot 4-pole structure used in this utility model.

[0030] Figure 13 This is the power waveform diagram of the 6-slot 4-pole structure used in this utility model.

[0031] Figure 14 This is a torque waveform diagram of the 6-slot 8-pole structure used in this utility model.

[0032] Figure 15 This is the power waveform diagram of the 6-slot 8-pole structure used in this utility model. Detailed Implementation

[0033] Example 1, see Figures 1 to 7 This embodiment provides a three-phase high power density PCB stator winding structure, which includes a PCB coil board 1, the overall outline of which is circular.

[0034] The PCB coil board 1 has six layers. The six-layer design ensures improved motor performance while also taking into account the feasibility of the manufacturing process and cost control. Compared with designs with more layers, the six-layer structure is relatively easier to process and manufacture, and can effectively meet the requirements of micro fan motors for coil density and size.

[0035] Each layer of the PCB coil board 1 is symmetrically divided into six coil regions. Each of the six coil regions has a roughly identical, spirally wound 2D printed coil, forming six windings. The 2D printed coils are printed in a spiral pattern. The line spacing D within the same 2D printed coil is the same as the spacing d between two adjacent 2D printed coils on the same layer. The 2D printed coils in each layer are connected through internal or external interlayer vias. This spiral coil printing method fully utilizes the space of the PCB coil board, improves coil area utilization, increases effective conductor length, and thus improves the electromagnetic performance and power density of the motor. The uniform spacing between coils in each layer and the orderly series connection between layers maximize the winding density, thereby improving motor efficiency. Windings of the same coil region but on different layers are connected in series via internal or external interlayer vias to form windings U1, V1, W1, U2, V2, and W2. Windings U1 and U2 are 180° mechanically separated and connected in series to form the U-phase winding; windings V1 and V2 are 180° mechanically separated and connected in series to form the V-phase winding; windings W1 and W2 are 180° mechanically separated and connected in series to form the W-phase winding. Windings U1, V1, and W1 are each 120° electrically separated (60° mechanically), and windings U2, V2, and W2 are each 120° electrically separated (60° mechanically). The combination of the U-phase, V-phase, and W-phase windings constitutes a three-phase motor winding structure. The alternating changes in the three-phase current generate a rotating magnetic field, driving the motor rotor to rotate. Compared to single-phase windings, three-phase windings can generate a more stable rotating magnetic field, reduce motor torque fluctuations, and improve the smoothness and reliability of motor operation. They also help improve motor efficiency and power factor, enabling them to better meet heat dissipation requirements in micro fan applications.

[0036] Specifically, the winding U1 is formed by sequentially connecting 2D printed coils in the first coil region of the first, second, third, fifth, sixth and fourth layers of the PCB coil board; the winding U2 is formed by sequentially connecting 2D printed coils in the fourth coil region of the fourth, sixth, fifth, third, first and second layers of the PCB coil board; the windings U1 and U2 are connected in series on the fourth layer of the PCB coil board to form a U-phase winding.

[0037] The winding V1 is formed by connecting 2D printed coils in series in the second coil region of the first, second, third, fourth, sixth and fifth layers of the PCB coil board; the winding V2 is formed by connecting 2D printed coils in series in the fifth coil region of the fifth, sixth, fourth, third, first and second layers of the PCB coil board; the winding V1 and the winding V2 are connected in series on the fifth layer of the PCB coil board to form a V-phase winding.

[0038] The winding W1 is formed by connecting 2D printed coils in series in the third coil region of the first, second, third, fifth, fourth and sixth layers of the PCB coil board; the winding W2 is formed by connecting 2D printed coils in series in the sixth coil region of the sixth, fourth, fifth, third, first and second layers of the PCB coil board; the windings W1 and W2 are connected in series on the sixth layer of the PCB coil board to form a W-phase winding.

[0039] The connection method for each winding is as follows:

[0040] S1. Winding U1: Arrange the head wire of winding U1 in the first layer to form the head end of the U phase, and then connect them according to the following winding method and inter-layer sequence;

[0041] 1.1 First layer: The winding of the first layer is wound from the outside to the inside, and the inner end of the winding of the first layer is connected in series to the inner end of the winding located in the second layer through the internal interlayer via;

[0042] 1.2 Second layer: The winding of the second layer is wound from the inside to the outside, and the outer end of the winding of the second layer is connected in series to the outer end of the winding located in the third layer through the external interlayer via;

[0043] 1.3 Third layer: The winding of the third layer is wound from the outside to the inside, and the inner end of the winding of the third layer is connected in series to the inner end of the winding located in the fifth layer through the internal interlayer via.

[0044] 1.4 Fifth layer: The fifth layer winding is wound from the inside to the outside, and the outer end of the fifth layer winding is connected in series to the outer end of the sixth layer winding through the external interlayer via;

[0045] 1.5 Sixth layer: The winding of the sixth layer is wound from the outside to the inside, and the inner end of the winding of the sixth layer is connected in series with the inner end of the winding located in the fourth layer through the internal interlayer via.

[0046] 1.7 Fourth layer: The winding of the fourth layer is wound from the inside to the outside, and the outer end of the winding of the fourth layer is connected in series with winding U2 through the same layer cross wire;

[0047] S2, Winding U2: Arrange the head wire of winding U2 in the fourth layer to connect with the outer end of the winding in the fourth layer of winding U1, and then connect them according to the following winding method and inter-layer sequence;

[0048] 2.1 Fourth layer: The winding of the fourth layer is wound from the outside to the inside, and the inner end of the winding of the fourth layer is connected in series to the inner end of the winding located in the sixth layer through the internal interlayer via.

[0049] 2.2 Sixth layer: The winding of the sixth layer is wound from the inside to the outside, and the outer end of the winding of the sixth layer is connected in series to the outer end of the winding located in the fifth layer through the external interlayer via;

[0050] 2.3 Fifth layer: The fifth layer winding is wound from the outside to the inside, and the inner end of the fifth layer winding is connected in series to the inner end of the third layer winding through the internal interlayer via.

[0051] 2.4 Third layer: The winding of the third layer is wound from the inside to the outside, and the outer end of the winding of the third layer is connected in series to the outer end of the winding of the first layer through the external interlayer via;

[0052] 2.5 First layer: The winding of the first layer is wound from the outside to the inside, and the inner end of the winding of the first layer is connected in series to the inner end of the winding located in the second layer through the internal interlayer via;

[0053] 2.6 Second layer: The winding of the second layer is wound from the inside to the outside, and the outer end of the winding of the second layer forms the tail end of the U phase;

[0054] S3. Winding V1: Arrange the head wire of winding V1 in the first layer to form the head end of the V phase, and then connect them according to the following winding method and inter-layer sequence.

[0055] 3.1 First layer: The winding of the first layer is wound from the outside to the inside, and the inner end of the winding of the first layer is connected in series to the inner end of the winding of the second layer through the internal interlayer via;

[0056] 3.2 Second layer: The winding of the second layer is wound from the inside to the outside, and the outer end of the winding of the second layer is connected in series to the outer end of the winding located in the third layer through the external interlayer via;

[0057] 3.3 Third layer: The winding of the third layer is wound from the outside to the inside, and the inner end of the winding of the third layer is connected in series to the inner end of the winding located in the fourth layer through the internal interlayer via.

[0058] 3.4 Fourth layer: The winding of the fourth layer is wound from the inside to the outside, and the outer end of the winding of the fourth layer is connected in series to the outer end of the winding located in the sixth layer through the external interlayer via;

[0059] 3.5 Sixth layer: The winding of the sixth layer is wound from the outside to the inside, and the inner end of the winding of the sixth layer is connected in series with the inner end of the winding located in the fifth layer through the internal interlayer via.

[0060] 3.7 Fifth layer: The fifth layer winding is wound from the inside to the outside, and the outer end of the fifth layer winding is connected in series with winding V2 through the same layer cross wire;

[0061] S4. Winding V2: Arrange the lead wire of winding V2 in the fifth layer to connect with the outer end of the winding in the fifth layer of winding V1, and then connect them according to the following winding method and interlayer sequence.

[0062] 4.1 Fifth layer: The fifth layer winding is wound from the outside to the inside, and the inner end of the fifth layer winding is connected in series to the inner end of the sixth layer winding through the internal interlayer via.

[0063] 4.2 Sixth layer: The winding of the sixth layer is wound from the inside to the outside, and the outer end of the winding of the sixth layer is connected in series to the outer end of the winding located in the fourth layer through the external interlayer via;

[0064] 4.3 Fourth layer: The winding of the fourth layer is wound from the outside to the inside, and the inner end of the winding of the fourth layer is connected in series with the inner end of the winding located in the third layer through the internal interlayer via.

[0065] 4.4 Third layer: The winding of the third layer is wound from the inside to the outside, and the outer end of the winding of the third layer is connected in series to the outer end of the winding of the first layer through the external interlayer via;

[0066] 4.5 First layer: The winding of the first layer is wound from the outside to the inside, and the inner end of the winding of the first layer is connected in series to the inner end of the winding of the second layer through the internal interlayer via;

[0067] 4.6 Second layer: The winding of the second layer is wound from the inside to the outside, and the outer end of the winding of the second layer forms the tail end of the V phase;

[0068] S5. Winding W1: Arrange the head wire of winding W1 in the first layer to form the head end of phase W, and then connect them according to the following winding method and layer sequence.

[0069] 5.1 First layer: The winding of the first layer is wound from the outside to the inside, and the inner end of the winding of the first layer is connected in series to the inner end of the winding located in the second layer through the internal interlayer via;

[0070] 5.2 Second layer: The winding of the second layer is wound from the inside to the outside, and the outer end of the winding of the second layer is connected in series to the outer end of the winding located in the third layer through the external interlayer via;

[0071] 5.3 Third layer: The winding of the third layer is wound from the outside to the inside, and the inner end of the winding of the third layer is connected in series to the inner end of the winding located in the fourth layer through the internal interlayer via.

[0072] 5.4 Fifth layer: The fifth layer winding is wound from the inside to the outside, and the outer end of the fifth layer winding is connected in series to the outer end of the sixth layer winding through the external interlayer via.

[0073] 5.5 Fourth layer: The winding of the fourth layer is wound from the outside to the inside, and the inner end of the winding of the fourth layer is connected in series to the inner end of the winding located in the sixth layer through the internal interlayer via.

[0074] 5.7 Sixth layer: The winding of the sixth layer is wound from the inside to the outside, and the outer end of the winding of the sixth layer is connected in series with winding W2 through the same layer cross wire;

[0075] S6. Winding W2: Arrange the lead wire of winding W2 in the sixth layer to connect with the outer end of the winding in the fifth layer of winding W1, and then connect according to the following winding method and inter-layer sequence.

[0076] 6.1 Sixth layer: The winding of the sixth layer is wound from the outside to the inside, and the inner end of the winding of the sixth layer is connected in series to the inner end of the winding located in the fourth layer through the internal interlayer via.

[0077] 6.2 Fourth layer: The winding of the fourth layer is wound from the inside to the outside, and the outer end of the winding of the fourth layer is connected in series to the outer end of the winding located in the fifth layer through the external interlayer via;

[0078] 6.3 Fifth layer: The fifth layer winding is wound from the outside to the inside, and the inner end of the fifth layer winding is connected in series to the inner end of the third layer winding through the internal interlayer via.

[0079] 6.4 Third layer: The winding of the third layer is wound from the inside to the outside, and the outer end of the winding of the third layer is connected in series to the outer end of the winding of the first layer through the external interlayer via;

[0080] 6.5 First layer: The winding of the first layer is wound from the outside to the inside, and the inner end of the winding of the first layer is connected in series to the inner end of the winding located in the second layer through the internal interlayer via;

[0081] 6.6 Second layer: The winding of the second layer is wound from the inside to the outside, and the outer end of the winding of the second layer forms the tail end of the W phase;

[0082] The head and tail ends of phases U, V, and W can be interchanged by reverse winding.

[0083] To facilitate further explanation of the interlayer via connection logic and winding connection method, external and internal interlayer vias are uniformly named VX, where V represents the interlayer via and X represents the interlayer via number.

[0084] The coil regions are named LXY, where L represents 2D printed coil 2, X indicates the region number, and Y indicates the layer number. Taking a six-region division as an example, the PCB coil board 1 is divided into six coil regions at 60-degree intervals. For example, L12 represents the 2D printed coil on the second layer of the first region. The coils at each of these six positions are collectively called LXX coil groups. For instance, the six coils in the first region are collectively called the L1X coil group (abbreviated as L1X); the six coils in the fourth region are collectively called the L4X coil group (abbreviated as L4X).

[0085] 2D printed coils 2 of different layers but with the same coil number can be connected through interlayer vias to form a winding. There are six windings in total: winding U1, winding V1, winding W1, winding U2, winding V2, and winding W2. Each winding area has two external interlayer vias and three internal interlayer vias, for a total of thirty interlayer vias across the six PCB stator winding areas. Each interlayer via connects only two 2D printed coils. Two windings 180° apart mechanically constitute one phase, and the six windings form three phases: U phase, V phase, and W phase. For example, L1X and L4X form the U phase, L2X and L5X form the V phase, and L3X and L6X form the W phase.

[0086] See Figures 2 to 7 The head and tail lines of the three phases can be interchanged simultaneously, that is, the existing tail line can be reversed to the existing head line.

[0087] L1X connection logic: U1 connects to L11, L11 connects to L12 via V3, L12 connects to L13 via V1, L13 connects to L15 via V5, L15 connects to L16 via V2, and L16 connects to L14 via V4.

[0088] The connection logic of L4X is as follows: L44 is connected to L46 via V18, L46 is connected to L45 via V16, L45 is connected to L43 via V20, L43 is connected to L41 via V17, L41 is connected to L42 via V19, and L42 is connected to U2.

[0089] L1X and L4X are connected in series, specifically through L14 and L44 connected by a crossover line on the fourth layer, that is, the crossover line is connected by passing around the outer position of L24 and L34.

[0090] L2X connection logic: V1 connects to L21, L21 connects to L22 via V8, L22 connects to L23 via V6, L23 connects to L24 via V10, L24 connects to L26 via V7, and L26 connects to L25 via V9.

[0091] The connection logic of L5X is as follows: L55 is connected to L56 via V24, L56 is connected to L54 via V21, L54 is connected to L53 via V23, L53 is connected to L51 via V22, L51 is connected to L52 via V25, and L52 is connected to V2.

[0092] L2X and L5X are connected in series, specifically by connecting L25 and L55 on the same layer of the fifth floor, that is, the connection is made by the crossover line passing around the outer position of L35 and L45.

[0093] The connection logic of L3X is as follows: W1 connects to L31, L31 connects to L32 via V13, L32 connects to L33 via V11, L33 connects to L35 via V14, L35 connects to L34 via V12, and L34 connects to L36 via V15.

[0094] The connection logic of L6X is as follows: L66 is connected to L64 via V28, L64 is connected to L65 via V26, L65 is connected to L63 via V30, L63 is connected to L61 via V27, L51 is connected to L62 via V29, and L62 is connected to W2.

[0095] L3X and L6X are connected in series, specifically by L36 and L66 being connected by a crossover line on the sixth layer, that is, the crossover line is connected by passing around the outer position of L46 and L56.

[0096] The 2D printed coils 2 on each layer of the PCB coil board 1 have roughly the same shape. The outline of the 2D printed coil 2 is roughly in the shape of an isosceles trapezoid, with the upper bottom edge 21 close to the center of the circle. The upper bottom edge 21 and the two waist edges 22 are straight lines, and the lower bottom edge 23 is an arc. The center of the arc does not coincide with the center of the PCB coil board 1.

[0097] In this embodiment, the connection between the upper bottom edge 21 and the two waist edges of the 2D printed coil 2 is transitioned by an outer rounded corner, and the connection between the lower bottom edge 23 and the two waist edges 22 is transitioned by an inner rounded corner. The positions between the outer rounded corners of two adjacent 2D printed coils 2 form six outer triangular areas 11 on the PCB coil board 1, and the positions between the inner rounded corners of two adjacent 2D printed coils 2 form six inner triangular areas 12 on the PCB coil board 1. The rounded corner transition provides reasonable space for the subsequent setting of pads 13 and interlayer vias 14, facilitates circuit connection and layout, has high space utilization, and improves structural compactness.

[0098] The PCB coil board 1 has at least four pads 13 corresponding to the six outer triangular areas 11, distributed in the outer triangular areas. Taking six pads 13 as an example, there is one U pad, one V pad, one W pad, and three COM pads, forming a total of six pads 13. In the figure, they are represented as U1, V1, W1, U2, V2, and W2, that is, U2, V2, and W2 correspond to the three COM pads.

[0099] Placing pads 13 on the outer triangular area 11 as connection points makes full use of space, saves PCB space, and avoids the pads occupying extra space, which would affect the winding layout and the overall compactness of the motor structure. It also facilitates production and subsequent wiring operations. In other embodiments, the number of pads 13 can also be four, that is, three COM pads are combined into one COM pad, that is, the three COM terminals above are simplified into one COM pad, making the wiring more convenient.

[0100] External interlayer vias are located at the six inner triangular areas 12 of the PCB coil board 1, while internal interlayer vias are located at the geometric center of the 2D printed coil 2. Interlayer connections are achieved through internal and external interlayer vias, eliminating the need for wiring and resulting in a more compact and rational multi-layer winding structure. This facilitates further reduction in motor size and increases coil density. Specifically, each inner triangular area 12 has two external interlayer vias, and each 2D printed coil 2 has three internal interlayer vias at its geometric center, arranged in a straight line.

[0101] The internal or external interlayer vias are connected to only two of the 2D printed coils. This connection method improves the reliability and accuracy of the connection, reduces the complexity and potential failure points caused by connecting too many coils through vias, and helps to improve the yield rate of motor production and long-term operational stability.

[0102] Example 2, see Figures 8 to 9 This embodiment provides a miniature fan, which includes the aforementioned three-phase high power density PCB stator winding structure. Specifically, the miniature fan includes a base 3, a top cover 4, a fan rotor assembly 5, an FPC flexible board 6, a PCB coil board 1, and a back iron 7.

[0103] The FPC flexible board 6 is disposed within the base 31. Preferably, the FPC flexible board 6 is directly glued and fixed within the base 31 using adhesive. Compared to traditional mechanical fixing methods, this avoids the additional space occupation and structural complexity caused by screws and other fasteners, and is also simple to operate.

[0104] The FPC flexible board 6 has six solder points, corresponding to the solder pads U1, V1, W1, U2, V2, and W2 on the PCB coil board 1, and are soldered to the beginning and end of the U, V, and W phases respectively. The solder pads U1, V1, W1, U2, V2, and W2 on the PCB coil board 1 are soldered to the solder points on the FPC flexible board 6 using SMT technology, resulting in a strong bond, good structural stability, and no need for wiring. In other embodiments, the number of solder pads 13 can also be four, that is, merging the U2, V2, and W2 solder pads into a single COM solder pad, further simplifying the structure and making wiring easier.

[0105] The fan rotor assembly 5 is rotatably mounted on the base 3 corresponding to the position of the 2D printed coil 2, and the upper cover 4 is fastened to the base 3. Preferably, a waterproof sealant is provided between the upper cover 4 and the base 3 to improve the sealing effect and prevent external moisture, dust and other foreign objects from entering the interior of the miniature fan.

[0106] The base 3 has a central tube 31 located in the middle. The fan rotor assembly 5 includes fan blades 51, a motor housing 52, a shaft core 53, and a magnet 54. The fan blades 51 are sleeved on the motor housing 52. One end of the shaft core 53 is fixed to the center of the motor housing 52. The shaft core 53 is rotatably mounted on the central tube 31 via a bearing. The magnet 54 is located inside the motor housing 52 and corresponds to the 2D printed coil 2. When the 2D printed coil 2 is energized, the generated magnetic field drives the magnet 54 and the motor housing 52 to rotate together, thereby driving the fan blades 51 to rotate and achieve the function of blowing air for heat dissipation. If only a motor is needed, the fan blades 51 can be omitted.

[0107] The back iron 7 is embedded in the base 3. That is, during injection molding, the back iron 7 is pre-positioned in the mold cavity, and the base 3 is formed by injection molding, thus embedding the back iron 7 in the base 3, and corresponding to the position of the magnet 54. Because the back iron 7 is located inside the base 3 and is relatively high, the distance between it and the magnet 54 is shortened, which increases the magnetic pull and effectively reduces the eddy current effect, thereby improving motor efficiency. Preferably, a wear-resistant plate 8 is provided on the bottom surface inside the central tube 31 to support the shaft core 53, reducing frictional wear between the shaft core 53 and the base 31 during rotation, while also reducing noise and making operation more stable.

[0108] Example 3, see Figures 10 to 11 This embodiment provides a miniature fan that is basically similar to that of Embodiment 2, except that the base is replaced with an LDS base 9. The surface of the LDS base 9 is provided with an LDS circuit formed by the LDS process. The LDS circuit includes traces, solder joints, metal contacts, and other structures. The LDS circuit replaces the FPC flexible board 6. That is, the LDS circuit has six solder joints 91 corresponding to the solder pads U1, V1, W1, U2, V2, and W2 on the PCB coil board 1.

[0109] The pads U1, V1, W1, U2, V2, and W2 on the PCB coil board 1 are soldered to the six solder points 91 of the LDS circuit using SMT technology, thus achieving the same purpose of soldering and fixing. If the number of pads 13 is four, the number of solder points 91 on the LDS circuit is also reduced to four.

[0110] Experimental testing has shown that, compared with existing technologies, the miniature fan employing the three-phase high power density PCB stator winding structure of this invention has the following advantages:

[0111] 1. The entire three-phase high power density PCB stator winding structure is circular in shape to avoid interference with other components and facilitate its application in micro motor architecture.

[0112] 2. The shapes of each 2D printed coil 2 are roughly the same, and a symmetrical winding and wiring design is adopted. Specifically, the straight line segments of two adjacent 2D printed coils 2 in each layer are nearly equal in length, and the geometric center lines of the two 2D printed coils are approximately symmetrical to avoid torque imbalance, good electromagnetic force balance, and small torque fluctuation of the motor.

[0113] 3. The resistance values ​​of each phase are relatively uniform, which reduces the impact of phase current fluctuations on torque fluctuations.

[0114] 4. Since the outline of the 2D printed coil is roughly an isosceles trapezoid, and the blank areas formed by the inner and outer rounded corners create six outer triangular regions 11 and six inner triangular regions 12, this provides reasonable space for the placement of pads and interlayer vias, thereby maximizing the effective area of ​​the coil and improving motor performance. The electromagnetic simulation results of the motor are shown in Table 1:

[0115] Table 1

[0116] 6 6 slots 4 poles 2.03e-5 0.199 20.3％ 6 6 slots 8 poles 2.50e-5 0.181 27.4％

[0117] The connection logic for 6 slots with 4 poles and 6 slots with 8 poles is the same; only the number of poles on the magnets is different.

[0118] Resistance values ​​for each phase: U phase 18.1 ohms, V phase 18.0 ohms, W phase 18.1 ohms, resistivity based on 0.0185 Ohm.mm 2 / m calculation.

[0119] Simulation results for 6-slot 4-pole (19000 RPM) can be found here. Figure 12 and Figure 13 Simulation results for a 6-slot, 8-pole configuration (19000 RPM) can be found here. Figure 14 and Figure 15 .

[0120] It can be seen that the micro fan or motor using the three-phase high power density PCB stator winding structure of this utility model has good electromagnetic force balance, small torque fluctuation, and high efficiency.

[0121] Based on the disclosure and teachings of the above specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, this utility model is not limited to the specific embodiments disclosed and described above, and some modifications and changes to this utility model should also fall within the protection scope of the claims of this utility model. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on this utility model. As described in the above embodiments of this utility model, other stator structures, motors, or fans obtained using the same or similar structures are all within the protection scope of this utility model.

Claims

1. A three-phase high power density PCB stator winding structure, comprising a PCB coil board, characterized in that: The overall outline of the PCB coil board is circular. The PCB coil board has six layers, and each layer is symmetrically divided into six coil areas around the center. Each of the six coil areas has a 2D printed coil with a roughly the same shape and spiral winding, forming six windings. The windings of the same numbered coil area on different layers are connected in series through internal or external interlayer vias to form windings U1, winding V1, winding W1, winding U2, winding V2, and winding W2. The windings U1 and U2 are 180° apart mechanically and are connected in series to form the U-phase winding; Windings V1 and V2 are 180° apart mechanically and are connected in series to form a V-phase winding; Windings W1 and W2 are 180° apart mechanically and are connected in series to form the W-phase winding.

2. The three-phase high power density PCB stator winding structure according to claim 1, characterized in that: The winding U1 is formed by connecting 2D printed coils in series in the first coil area of ​​the first layer, second layer, third layer, fifth layer, sixth layer and fourth layer of the PCB coil board; The winding U2 is formed by connecting 2D printed coils in series in the fourth coil area of ​​the fourth layer, sixth layer, fifth layer, third layer, first layer and second layer of the PCB coil board; The windings U1 and U2 are connected in series on the fourth layer of the PCB coil board to form a U-phase winding.

3. The three-phase high power density PCB stator winding structure according to claim 1, characterized in that: The winding V1 is formed by connecting 2D printed coils in series in the second coil region located in the first, second, third, fourth, sixth and fifth layers of the PCB coil board; The winding V2 is formed by connecting 2D printed coils in series in the fifth coil region of the fifth, sixth, fourth, third, first and second layers of the PCB coil board; The windings V1 and V2 are connected in series on the fifth layer of the PCB coil board to form a V-phase winding.

4. The three-phase high power density PCB stator winding structure according to claim 1, characterized in that: The winding W1 is formed by connecting 2D printed coils in series in the third coil region of the first, second, third, fifth, fourth and sixth layers of the PCB coil board; The winding W2 is formed by connecting 2D printed coils in series in the sixth coil area of ​​the sixth layer, fourth layer, fifth layer, third layer, first layer and second layer of the PCB coil board; The windings W1 and W2 are connected in series on the sixth layer of the PCB coil board to form a W-phase winding.

5. The three-phase high power density PCB stator winding structure according to claim 1, characterized in that: The 2D printed coil has an outline that is roughly in the shape of an isosceles trapezoid, with the upper base edge close to the center of the PCB coil board. The upper base edge and the two waist edges are straight lines, and the lower base edge is an arc. The center of the arc does not coincide with the center of the PCB coil board.

6. The three-phase high power density PCB stator winding structure according to claim 5, characterized in that: The connection between the upper bottom edge and the two waist edges is transitioned by an outer rounded corner, and the connection between the lower bottom edge and the two waist edges is transitioned by an inner rounded corner. The position between the outer rounded corners of two adjacent 2D printed coils forms six outer triangular areas on the PCB coil board, and the position between the inner rounded corners of two adjacent 2D printed coils forms six inner triangular areas on the PCB coil board.

7. The three-phase high power density PCB stator winding structure according to claim 6, characterized in that: The PCB coil board has at least four pads distributed in the outer triangular area; the external interlayer via is located in the inner triangular area, and the internal interlayer via is located at the geometric center of the 2D printed coil.

8. The three-phase high power density PCB stator winding structure according to claim 7, characterized in that: The internal or external interlayer vias are connected to only two of the 2D printed coils.

9. An electric motor, characterized in that: It includes the three-phase high power density PCB stator winding structure as described in any one of claims 1-8.

10. A miniature fan, characterized in that: It includes the three-phase high power density PCB stator winding structure as described in any one of claims 1-8.

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