Stator structure for axial flux electric motor

Abstract

A stator structure (100) for an axial flux electric motor, the stator structure (100) including a plurality of magnetic poles, a plurality of magnetic-field interaction regions (111), and a plurality of conductor strands (120). Each magnetic-field interaction region (111) includes a plurality of axially arranged layers (L1, L2, L3 to Ln). Each conductor strand (120) passes through a lowest layer, and then ascends through a higher layer each time the conductor strand crosses to the magnetic-field interaction region (111) of the next magnetic pole, until the conductor ascends through the highest layer, such that the conductor strands are arranged in the same geometric order in the magnetic-field interaction regions of the magnetic poles. Alternatively, each conductor strand (120) passes through a highest layer, and then descends through a lower layer each time the conductor strand crosses to the magnetic-field interaction region (111) of the next magnetic pole, until the conductor strand descends through the lowest layer, such that the conductor strands are arranged in the same geometric order in the magnetic-field interaction regions of the magnetic poles. A secondary winding includes the conductor strands connected in series.

Description

Axial flux motor stator structure Technical Field

[0001] This invention relates to an electric motor structure, and more particularly to the stator structure of an axial flux motor. Background Technology

[0002] An electric motor is a component used to convert electrical energy into mechanical energy and is widely used in daily life. Current axial motors employ distributed winding, with conductors arranged circumferentially within the stator slots according to the corresponding magnetic pole positions. To effectively fill the slot space and improve the slot fill factor, the positions of two conductors in adjacent slots must be swapped axially at the protrusion before crossing to the next magnetic pole. This prevents the conductors from being further assembled into a complete winding after bending and shaping, requiring complex forming methods and equipment for the overall winding fabrication. Summary of the Invention

[0003] This invention proposes a stator structure for an axial flux motor, which solves the problems of the prior art.

[0004] According to some embodiments of the present invention, an axial flux motor stator structure includes a plurality of magnetic poles, a plurality of magnetic field regions, a plurality of conductor strands, and at least one secondary winding. Each magnetic field region includes a plurality of layers arranged axially along a rotation axis. The conductors constitute a multiphase winding, and each conductor strand, after passing through a lowest layer among the layers, ascends and passes through a higher layer among the layers as it moves to the magnetic field region corresponding to the next magnetic pole, until it ascends and passes through a highest layer among the layers, such that the conductor strands are arranged in the same geometric order in the magnetic field regions of the magnetic poles. Alternatively, each conductor strand, after passing through a highest layer among the layers, descends and passes through a lower layer among the layers as it moves to the magnetic field region corresponding to the next magnetic pole, until it descends and passes through a lowest layer among the layers, such that the conductor strands are arranged in the same geometric order in the magnetic field regions of the magnetic poles. Each phase of the winding includes at least one secondary winding, and each secondary winding includes a portion of the conductors connected in series.

[0005] According to some embodiments of the present invention, two secondary windings with the same geometric arrangement are connected in series by an axial connecting segment; or two secondary windings with the opposite geometric arrangement are connected in series by a layer connecting segment.

[0006] According to some embodiments of the present invention, two secondary windings with the same geometric arrangement are used to transmit current along the same circumferential direction, and two secondary windings with opposite geometric arrangements are used to transmit current along two opposite circumferential directions.

[0007] According to some embodiments of the present invention, the axial connecting segment connects two secondary windings of the same geometric arrangement between a lowest layer and a highest layer of the layers.

[0008] According to some embodiments of the present invention, the same-layer connection segment is located at a lowest layer or a highest layer among the layers to connect the secondary windings in series.

[0009] According to some embodiments of the present invention, each phase of the winding has a corresponding magnetic field region for each of the magnetic poles, and each magnetic field region has at least one secondary winding.

[0010] According to some embodiments of the present invention, each phase of the winding has two corresponding magnetic field regions adjacent to each of the magnetic poles along a circumferential direction, and each magnetic field region has at least one secondary winding, wherein the geometric arrangement of the secondary windings is either in the same direction or in opposite directions.

[0011] According to some embodiments of the present invention, each phase of the winding has at least three corresponding magnetic field regions adjacent to each of the magnetic poles along a circumferential direction, and each magnetic field region has at least one secondary winding, wherein the geometric arrangement of the secondary windings is either in the same direction or in opposite directions.

[0012] According to some embodiments of the present invention, a plurality of such secondary windings are connected in series to form a single phase winding, each of such secondary windings comprising N groups of conductors, each of the N groups of conductors comprising the same number of conductors, and the geometric arrangement of the N groups of conductors in the magnetic field regions corresponding to the magnetic poles is balanced relative to the rotation axis, wherein N is a positive integer greater than 1.

[0013] According to some embodiments of the present invention, the stator structure of the axial flux motor further includes a soft magnetic material body, which includes a plurality of slots, each slot corresponding to a magnetic field action area.

[0014] According to some embodiments of the present invention, each conductor includes a plurality of inner diameter protrusions, a plurality of receiving portions and a plurality of outer diameter protrusions, the receiving portions being located within the slots, the inner diameter protrusions being located within an internal space surrounding the rotation axis of the soft magnetic material body, and the outer diameter protrusions being exposed outside an outer diameter sidewall of the soft magnetic material body.

[0015] In summary, the axial flux motor stator structure of the present invention manufactures each conductor in a spiral arrangement with a circumferential ascending or descending structure. This conductor structure ensures that the relative vertical positions of different conductors remain unchanged during winding, avoiding vertical crossover. This allows the conductors to be easily assembled into a complete winding after forming, and the conductor arrangement effectively fills the slot space, increasing the slot fill factor. Furthermore, splitting a single-phase winding into n equal parts and balancing the back electromotive force of the split windings requires reducing the number of conductors in each of the aforementioned windings to 1 / n. Reconnecting the windings with reduced conductor numbers in series forms a balanced single-phase winding that has been split into n groups, with the number of conductor strands or winding turns reduced to 1 / n of the original.

[0016] The above description will be given in detail below with reference to the embodiments, and a further explanation of the technical solution of the present invention will be provided. Attached Figure Description

[0017] To make the above and other objects, features, advantages and embodiments of the present invention more apparent and understandable, the accompanying drawings are described below:

[0018] Figure 1 is a perspective view showing the stator structure of an axial flux motor according to an embodiment of the present invention;

[0019] Figure 2 is a perspective view of the soft magnetic material body in the stator structure of the axial flux motor of Figure 1;

[0020] Figure 3 is a perspective view of a conductor according to an embodiment of the present invention;

[0021] Figure 4 is a side view showing one strand of the conductor in Figure 3;

[0022] Figure 5 is a top view showing one strand of the conductor in Figure 4;

[0023] Figure 6 is a perspective view showing the stator structure of a coreless axial flux motor;

[0024] Figure 7 shows the conductor portion structure of the stator structure of the axial flux motor in Figure 6;

[0025] Figure 8 illustrates the geometric arrangement of the conductors of a single primary winding in the slot (magnetic field region) according to an embodiment of the present invention.

[0026] Figure 9 shows the geometric arrangement of the conductors of the two series-connected secondary windings in the slot (field of action region) as shown in Figure 8;

[0027] Figure 10 shows another geometric arrangement of the conductors of the two series-connected secondary windings, continuing from Figure 8, in the slot (field of action).

[0028] Figure 11 shows the geometric arrangement of the conductors of the three series-connected secondary windings in the slot (field of action region) as shown in Figure 9.

[0029] Figure 12 shows another geometric arrangement of the conductors of the three series-connected secondary windings in the slot (field of action region) continuing from Figure 9;

[0030] Figure 13 shows another geometric arrangement of the conductors of the three series-connected secondary windings in the slot (field of action region) as shown in Figure 9.

[0031] Figure 14 shows the geometric arrangement of the conductors of the four series-connected secondary windings in the slot (field of action region) continuing from Figure 11.

[0032] Figures 15A and 15B show the geometric arrangement of conductors split into two groups of split windings in slots (field of action region) when a single phase is split into two groups of split windings.

[0033] Figure 15C shows the geometric arrangement of the conductors in the slots (field of action) after the two groups of split-wound wires in Figures 15A and 15B are combined in series.

[0034] Figures 16A, 16B, and 16C illustrate the geometric arrangement of conductors split into three groups of windings within slots (field of action); and

[0035] Figure 16D shows the geometric arrangement of the conductors after being split and connected in series in Figures 16A, 16B, and 16C in the slot (field of action).

[0036] Explanation of reference numerals in the attached figures: 100: Axial flux motor stator structure; 100a: Coreless stator structure; 110: Soft magnetic material body; 110a: Slot; 110b: Internal space; 110c: Outer diameter sidewall; 110t: Silicon steel sheet; 111: Magnetic field action area; L1, L2, L3, Ln: Layer; 120: Conductor; 121: Conductor; 121b: Bottom end; 121t: Top end; 121o: Outer diameter protrusion; 121o1: Half; 121o2: Half; 121i: Inner diameter protrusion; 121i1: Half; 121i2: Half; 121r: Reception part; AX: Rotation axis; AD: Axial axis 1~24: Conductors A, G, B, H, C, I, D, J, E, K, F, L: Magnetic field region; CD1, CD2: Circumferential direction; SL_CON, W1_SLCON, W2_SLCON, W3_SLCON: Same-layer connection segment; WAX_CON: Axial connection segment of winding; W1_AXCON, W2_AXCON, W3_AXCON, AX_CON: Axial connection segment; W1_IN, W2_IN, W3_IN, IN: Current input label; W1_OUT, W2_OUT, W3_OUT, OUT: Current output label. Detailed Implementation

[0037] To provide a more detailed and complete description of the present invention, reference can be made to the accompanying drawings and the various embodiments described below, in which the same numbers represent the same or similar elements. Furthermore, well-known elements and steps are not described in the embodiments to avoid unnecessarily limiting the invention. In the embodiments and claims, unless specifically defined in the text, the words "a" and "the" may refer to a single or multiple entities.

[0038] Referring to Figures 1 and 2, the stator structure 100 of the axial flux motor includes a soft magnetic material body 110 and a plurality of conductor strands 120. The soft magnetic material body 110 has a plurality of magnetic poles and a plurality of slots 110a. In some embodiments of the present invention, the soft magnetic material body 110 includes 24 slots 110a through which the plurality of conductor strands 120 pass in a distributed winding manner to form a plurality of windings, i.e., a plurality of distributed windings. Taking a three-phase flux motor as an example, 24 slots 110a divided by 3 (phase) yields 8 magnetic poles. In other words, one magnetic pole covers three slots. In some embodiments of the present invention, the soft magnetic material body 110 is composed of a plurality of silicon steel sheets 110t stacked along the axial direction AD or along the radial direction. In some embodiments of the present invention, the soft magnetic material body 110 is composed of soft magnetic composite (SMC). In some embodiments of the present invention, each slot 110a includes a plurality of layers (L1, L2, L3 to Ln) arranged along the axial direction AD, and a single conductor occupies only a single layer when passing through the slot.

[0039] Referring to Figures 3, 4, and 5, conductor 121 is used to pass through slots 110a of the soft magnetic material body 110 to form a winding. In some embodiments of the present invention, each conductor 121 includes a plurality of inner diameter protrusions 121i, a plurality of receiving portions 121r, and a plurality of outer diameter protrusions 121o. Each receiving portion 121r is located within a corresponding slot of the soft magnetic material body 110 and connects between the corresponding inner diameter protrusion 121i and outer diameter protrusion 121o. The soft magnetic material body 110 is generally a hollow columnar structure. The inner diameter protrusions 121i are located in the internal space 110b of the soft magnetic material body 110, and the outer diameter protrusions 121o are exposed outside the outer diameter sidewalls 110c of the soft magnetic material body 110 (refer to Figure 5). The internal space 110b is located between the soft magnetic material body 110 and a central axis, that is, the soft magnetic material body 110 surrounds the central axis to form the internal space 110b. In some embodiments of the present invention, each conductor 121 includes a plurality of inner diameter protrusions 121i located within the inner space 110b surrounding the axis of the soft magnetic material body 110 (see FIG. 5), and the two halves (121i1, 121i2) of each inner diameter protrusion 121i have a layer difference along the axial direction AD (see FIG. 3, half 121i2 is one layer higher than half 121i1). In some embodiments of the present invention, each conductor 121 includes a plurality of outer diameter protrusions 121o exposed outside the outer diameter sidewall 110c of the soft magnetic material body 110 (see FIG. 5), and the two halves (121o1, 121o2) of each outer diameter protrusion 121o have a layer difference along the axial direction AD (see FIG. 3, half 121o2 is one layer higher than half 121o1). In some embodiments of the invention, after each conductor 121 passes through a lowest layer (see Figure 4, for example, the bottom end 121b is located at layer L1), it ascends and passes through a higher layer (e.g., L2) at each position reaching the next magnetic pole, until it ascends and passes through a highest layer (see Figure 4, for example, the top end 121t is located at layer Ln). Alternatively, after each conductor 121 passes through a highest layer (see Figure 4, for example, the top end 121t is located at layer Ln), it descends and passes through a lower layer at each position reaching the next magnetic pole, until it ascends and passes through a lowest layer (see Figure 4, for example, the bottom end 121b is located at layer L1). In some embodiments of the invention, each conductor 121 is formed by bending a continuous linear conductor. In other embodiments of the invention, each conductor 121 comprises a plurality of linear conductors assembled or welded together.

[0040] Please refer to Figures 6 and 7. Figure 6 shows a coreless stator structure 100a of an axial flux motor with a plurality of conductors 120. This coreless stator structure 100a achieves a simple structure by not providing a soft magnetic material body (e.g., the soft magnetic material body 110 in Figures 1 and 2). Although no soft magnetic material body is provided, the coreless stator structure 100a still has a plurality of magnetic poles and a plurality of layers, and the conductors 120 have similar characteristics to the conductor 121 shown in Figure 5. Each conductor 120 moves from one magnetic pole position to the next magnetic pole position after passing through one of the lowest layers, while simultaneously rising to a higher layer position, until it reaches the highest layer position. Alternatively, each conductor 120 moves from one magnetic pole position to the next magnetic pole position after passing through one of the highest layers, while simultaneously descending to a lower layer position, until it descends to the lowest layer position. The axial stacking of conductors constitutes the magnetic field region 111 (see Figure 7). These magnetic field regions 111 are arranged symmetrically along the circumferential direction, adjacent to each other. Each magnetic field region 111 contains layers (L1, L2, L3 to Ln) stacked along the axial direction. When a single conductor passes through a slot or magnetic field region 111, it occupies only a single layer. The area of ​​conductor stacking within each slot 110a in Figure 2 is also called the magnetic field region.

[0041] Please refer to Figure 8, which shows the geometric arrangement of the conductor housing of a single primary winding in the slot (magnetic field region). The figure represents a view from the outer diameter to the inner diameter or from the inner diameter to the outer diameter. Each magnetic field region 111 in the figure contains 12 layers arranged along the axial direction AD. This embodiment contains a secondary winding consisting of 6 conductors (i.e., conductors 1 to 6). The secondary winding enters the highest layer of the magnetic field region 111 from the layer labeled IN. The arrangement of conductors 1 causes the current to decrease by one layer each time it crosses a magnetic pole, until the lowest layer, forming a spiral geometric arrangement (please also refer to Figures 3 and 4). For example, conductor 1 passes through all layers labeled 1 in the magnetic field region 111 in the figure, forming a spiral geometric arrangement (refer to the arrangement indicated by the dashed lines). Then, through a winding axial connection segment WAX_CON, the current enters the highest layer of the next conductor 2, continuing with the same geometric arrangement, decreasing by one layer each time it crosses a magnetic pole, i.e., all layers labeled 2 form a spiral geometric arrangement. In the same manner, through multiple axial connecting segments of the windings (i.e., the bold arrows similar to WAX_CON), the current enters the conductors (3, 4, 5, 6) and sequentially passes through the layers of the magnetic field region 111 in the diagram, forming a spiral geometric arrangement. Connecting these conductors 1 to 6 in series forms the secondary winding. At this point, the current flows out from the lowest layer of the last conductor 6 (i.e., the lowest layer labeled OUT). All six conductors (1 to 6) of the secondary winding are used to transmit current along the circumferential direction CD1, for example, counterclockwise.

[0042] Referring to Figure 9, following Figure 8, the geometric arrangement of conductors (7-12) in the slots (magnetic field region) of another secondary winding is shown. To clearly show the axial connection segment WAX_CON of conductors (7-12), the axial connection segments of conductors 1-6 are omitted. If each phase of the multiphase winding contains two adjacent magnetic field regions 111 and each conductor (1-6 and 7-12) is arranged in a spiral geometry in the same direction, the current can be connected in series through the axial connection segment AX_CON to allow current to enter from one secondary winding (containing conductors 1-6) to another secondary winding (containing conductors 7-12). For example, conductor 1 of one secondary winding is wound in a descending manner until the lowest layer of conductor 6 is completed. Then, it is connected in series through the axial connection segment AX_CON to the highest layer of conductor 7 of another secondary winding. Conductor 7 is then wound in a descending manner to the lowest layer. The above method is repeated, with the axial connection segment AX_CON connected to the highest layer of conductor 8, and conductors 9, 10, 11, etc. are wound in sequence until the lowest layer of conductor 12. The conductors (7-12) of the secondary winding have the exact same geometric order as the conductors (1-6) of the secondary winding. This allows the conductors to fill either the odd or even layers of the two adjacent magnetic field zones. All 12 conductors (1-12) of the two secondary windings are used to transmit current along the circumferential direction CD1. The current exits from the lowest layer of the last conductor 12 (i.e., the position marked OUT).

[0043] Referring to Figure 10, following Figure 8, the geometric arrangement of conductors (7-12) in the slots (magnetic field regions) differs from that in Figure 9. In this embodiment, each phase of the multiphase winding contains a magnetic field region 111. A secondary winding winds descends in a descending manner. After winding conductors 1 to 6, the current in conductor 6 can be guided in series to another secondary winding conductor 7 of another magnetic pole through a connecting segment SL_CON located at the same layer (the bottom layer in this embodiment). The conductors (7-12) of the secondary windings have a different helical geometric sequence than the conductors (1-6) of the secondary windings, and the current direction of conductors (7-12) is reversed relative to the positions of the magnetic poles by the series connection segment SL_CON (CD1 is changed to CD2). Unlike conductors (1-6), conductors (7-12) wind each conductor sequentially until the current flows out from the highest layer of the last conductor 12 (i.e., the highest layer labeled OUT). Conductors (7-12) are used to transmit current along another circumferential direction CD2, which is opposite to the circumferential direction CD1 of conductors (1-6). Circumferential direction CD1 is, for example, counterclockwise, while circumferential direction CD2 is, for example, clockwise. Furthermore, in this embodiment, the conductors (1-6) of each corresponding secondary winding and the conductors (7-12) of the other secondary winding are located in the same magnetic field region 111 and are staggered from each other by layer.

[0044] In summary, in Figure 9, the two secondary windings arranged in the same direction are connected in series by an axial connecting segment AX_CON, and the current directions of the two secondary windings are the same (CD1). In Figure 10, the two secondary windings arranged in opposite directions are connected in series by a layer-connecting segment SL_CON, and the current directions of the two secondary windings are different (CD1 and CD2).

[0045] Referring to Figure 11, which follows Figure 9, the geometric arrangement of the conductors (13-18) of the secondary winding in the slots (magnetic field regions) is shown. To clearly show the axial connection segment WAX_CON of the secondary winding conductors (13-18), the axial connection segments of the conductors (1-6) and conductors (7-12) of the other secondary windings are omitted. In this embodiment, each phase of the multiphase winding contains two adjacent magnetic field regions 111. Current can be guided from the secondary winding conductor 12 to another secondary winding conductor 13 at the other magnetic pole through the same-layer connection segment SL_CON located at both ends on the same layer. The secondary winding conductors (13-18) have a different helical conductor geometry than the secondary winding conductors (7-12) and secondary winding conductors (1-6). In detail, the conductors (13-18) of the secondary winding winds wind in a climbing manner, while the conductors (7-12) and (1-6) of the secondary winding winds wind in a descending manner. Therefore, the current direction is reversed to match the magnetic pole definition (CD1 is changed to CD2). Thus, after the conductor 12 of the secondary winding winds winds to the lowest layer, the current is conducted to the lowest layer of the conductor 13 of the other secondary winding winds through the same-layer connection segment SL_CON. The current is transmitted along the circumferential direction CD2 in the conductors (13-18) of the secondary winding winds. Each time a magnetic pole is crossed, the current rises one layer. Each conductor (13-18) of the secondary winding winds transmits current along the circumferential direction CD2 and is connected in series with each other through the winding axial connection segment WAX_CON. The current flows out from the highest layer of the last conductor 18 (i.e., the highest layer labeled OUT). In addition, the conductors (1-6) of the secondary winding winds are in adjacent magnetic field action regions 111 with the conductors (7-12) and (13-18) of the secondary winding winds. Furthermore, the conductors (7-12) of the secondary winding and the conductors (13-18) of the secondary winding are located in the same magnetic field region 111, and are staggered from each other by layer.

[0046] Please refer to Figure 12, which is followed by Figure 9, showing a geometric arrangement of conductors (13-18) in the slots (magnetic field regions) that differs from that in Figure 11. To clearly show the axial connection segment WAX_CON of the conductors (13-18) of the secondary winding, the axial connection segments of conductors (1-6) and conductors (7-12) of other secondary windings are omitted. In this embodiment, each phase of the multiphase winding contains two adjacent magnetic field regions 111. If the winding of the same phase is designed to fill more than one magnetic field region, adjacent magnetic field regions 111 must also be filled, but these adjacent magnetic field regions do not need to be completely filled. For example, each conductor (13-18) of the secondary winding can be filled into two adjacent magnetic field regions 111 of the same phase. In detail, this embodiment is a variation of the one shown in Figure 8. The secondary winding conductors (1-6) and (7-12) are located in two adjacent magnetic field action regions 111, but the secondary winding conductors (13-18) are arranged at intervals. Referring to Figure 12, the secondary winding conductors (13-18) first fill the left layer of the leftmost two magnetic field action regions 111 together with the secondary winding conductors (1-6), and then fill the second group to the right together with the secondary winding conductors (7-12). The two magnetic field action zones 111 on the right side are filled with the secondary winding conductors (1-6) and then the two magnetic field action zones 111 on the left side are filled with the secondary winding conductors (7-12) and then the two magnetic field action zones 111 on the right side are filled with the secondary winding conductors (7-12). This arrangement is repeated in a cycle. The secondary winding conductors (13-18) are arranged in an ascending manner, while the secondary winding conductors (1-6) and the secondary winding conductors (7-12) are arranged in a descending manner.

[0047] Please refer to Figure 13, which is followed by Figure 9, showing a geometric arrangement of the conductors (13-18) of the secondary winding in the slots (magnetic field regions) that differs from Figures 11 and 12. To clearly show the axial connection segment WAX_CON of the conductors (13-18) of the secondary winding, the axial connection segments of the conductors (1-6) and (7-12) of other secondary windings are omitted. In this embodiment, each phase of the multiphase winding contains three adjacent magnetic field regions 111. If the winding of the same phase is designed such that each magnetic pole fills three adjacent magnetic field regions 111, a different secondary winding and winding structure can be formed. This embodiment can connect six sets of secondary windings with the same geometric arrangement. Specifically, the secondary winding conductors (1-6), (7-12), and (13-18) all wind in a descending manner, and each secondary winding is respectively arranged in one of the three adjacent magnetic field regions 111 and circumferentially. It should be noted that, based on the configuration of this embodiment, each magnetic pole corresponding to each phase winding can be expanded into a structure with four or more adjacent magnetic field action regions 111. For example, it is feasible to use a larger stator structure to accommodate more magnetic field action regions 111. The various forms of magnetic field action regions 111 and secondary windings vary depending on the winding requirements and stator design.

[0048] Referring to Figure 14, the geometric arrangement of the conductors (19-24) of the secondary winding following Figure 11 in the slots (magnetic field regions) is shown. To clearly show the axial connection segment WAX_CON of the conductors (19-24) of the secondary winding, the axial connection segments of the conductors (1-6), (7-12), and (13-18) of the other secondary windings are omitted. In this embodiment, each phase of the multiphase winding contains two adjacent magnetic field regions 111. If each phase of the multiphase winding needs to fill two adjacent magnetic field regions 111, conductors (1-6) and (7-12) can be connected in series through the axial connection segment AX_CON, and conductors (13-18) and (19-24) can be connected in series. Furthermore, conductor 12 of the conductors (7-12) of the secondary winding and conductor 13 of the conductors (13-18) of the secondary winding can be connected in series through the same-layer connection segment SL_CON. The conductors of the secondary winding (13-18) and the secondary winding conductors (19-24) wind in a climbing manner and have a different helical conductor geometry than the conductors of the secondary winding (1-6) and the secondary winding conductors (7-12). Therefore, the two sets of current directions (CD1 and CD2) corresponding to these secondary windings are reversed in accordance with the magnetic pole definition. This allows the conductors to fill all layers of the two adjacent magnetic field regions 111. Other configurations are similar to those in Figures 9 to 13 above, and will not be described in detail here.

[0049] Please refer to Figures 15A, 15B, and 15C, which show the geometric arrangement of the conductors of the two groups of split single-phase windings (the magnetic field region) in the slots, where the three sets of secondary windings in Figure 12 are split into two groups of balanced single-phase windings. The three sets of secondary windings include secondary winding 1, secondary winding 2, and secondary winding 3. Secondary winding 1 includes conductors 1 to 6, secondary winding 2 includes conductors 7 to 12, and secondary winding 3 includes conductors 13 to 18. First, in Figure 15A, the split winding A includes conductors 1-3 of the first group of secondary winding 1, conductors 10-12 of secondary winding 2, and conductors 13-15 of secondary winding 3. The first group of conductors of secondary winding 1, secondary winding 2, and secondary winding 3 of the split winding A are connected in series through the same-layer connection section W1_SLCON and the axial connection section W1_AXCON. For example, after conductor 3 of secondary winding 1 is wound to the lowest layer, conductor 10 of secondary winding 2, which is located at the highest layer, is connected in series through the axial connection section W1_AXCON. Similarly, after conductor 12 of secondary winding 2 is wound to the lowest layer, conductor 13 of secondary winding 3, which is also located at the lowest layer, is connected in series through the same-layer connection section W1_SLCON. Next, in Figure 15B, the split winding B includes conductors 4-6 of the second group of secondary winding 1, conductors 7-9 of the second group of secondary winding 2, and conductors 16-18 of the second group of secondary winding 3. The second group of conductors of the second group of secondary winding 1, secondary winding 2, and secondary winding 3 of the split winding B are connected in series through the same-layer connection section W2_SLCON and the axial connection section W2_AXCON. For example, after the conductor 6 of the secondary winding 1 is wound to the lowest layer, the conductor 7 of the secondary winding 2, which is located at the highest layer, is connected in series through the axial connection section W2_AXCON. Similarly, after the conductor 9 of the secondary winding 2 is wound to the lowest layer, the conductor 16 of the secondary winding 3, which is also located at the lowest layer, is connected in series through the same-layer connection section W2_SLCON. Finally, in Figure 15C, the two types of split windings mentioned in Figures 15A and 15B are combined to form split windings A and B with symmetrical arrangement of the receiving parts about the rotation axis AX in magnetic field regions A / G, B / H, C / I, D / J, E / K, and F / L. This balances the back electromotive force of the single-phase winding as a whole, and reduces the number of conductor strands or winding turns required to form the overall winding to 1 / 2.

[0050] Please refer to Figures 16A, 16B, 16C, and 16D, which show the geometric arrangement of conductors split into three groups of windings in the slots (magnetic field region). The two secondary windings include secondary winding 1 and secondary winding 2. Secondary winding 1 includes conductors 1-6, and secondary winding 2 includes conductors 7-12. It should be noted that in this embodiment, secondary winding 1 and secondary winding 2 are wound in descending and ascending directions, respectively; that is, secondary winding 1 and secondary winding 2 have opposite geometric arrangements, and secondary winding 1 (conductors 1-6) transmits current along the circumferential direction CD1, while secondary winding 2 (conductors 7-12) transmits current along the circumferential direction CD2. In Figure 16A, split winding A includes conductors 1-2 of secondary winding 1 and conductors 11-12 (W1_IN) of secondary winding 2 of the first group. The first group conductors of the two secondary windings of split winding A are connected in series by the same-layer connecting segment W1_SLCON, that is, conductor 2 of secondary winding 1 and conductor 11 of secondary winding 2 are connected in series. In Figure 16B, split winding B includes conductors 3-4 of secondary winding 1 and conductors 9-10 of secondary winding 2 of the second group. The second group conductors of the two secondary windings of split winding B are connected in series by the same-layer connecting segment W2_SLCON, that is, conductor 4 of secondary winding 1 and conductor 9 of secondary winding 2 are connected in series. In Figure 16C, the split winding C includes conductors 5-6 of the third group of secondary winding 1 and conductors 7-8 of secondary winding 2. The conductors of the third group of the two secondary windings of the split winding C are connected in series through the same-layer connecting section W3_SLCON, that is, conductor 6 of secondary winding 1 and conductor 7 of secondary winding 2 are connected in series. In Figure 16D, the three split windings mentioned in Figures 16A, 16B and 16B are combined to form split windings A, B and C in magnetic field regions A / E / I, B / F / J, C / G / K and D / H / L respectively. The number and position of the receiving parts of these split windings are symmetrical about the rotation axis AX, thereby balancing the back electromotive force of the single-phase winding as a whole, and reducing the number of conductor strands or turns required to form the overall winding to 1 / 3. Although the above examples only illustrate the method of splitting a single phase into two groups (Figure 15) or three groups (Figure 16) for winding, the method of splitting a single phase into four or more groups for winding can also be implemented in a similar way based on the above grouping configuration. That is, a single phase can be split into N groups of winding according to winding requirements or stator design, so that the number of conductor strands or winding turns required to form the overall winding can be reduced to 1 / N, where N is a positive integer greater than 1, that is, splitting into 2 groups, 3 groups, 4 groups, 5 groups, ... N groups of winding.

[0051] The axial flux motor stator structure of the present invention can be extended to the application of N-group split windings based on different numbers of phases, magnetic poles, slots (magnetic field action areas), and layers, where N is a positive integer greater than 1. Through the aforementioned method, the number and position of the receiving portions of the split windings A, B, C to N can be symmetrical about the rotation axis AX, thereby balancing the back electromotive force of the entire winding, and reducing the number of conductor strands or winding turns required to form the entire winding to 1 / N.

[0052] The axial flux motor stator structure of this invention uses a spiral arrangement of each conductor, with a spiral-shaped ascending or descending structure along the circumference. This conductor structure ensures that the relative vertical positions of different conductors remain constant during winding, preventing vertical crossover. This allows the conductors to be easily assembled into a complete winding after forming, and the conductor arrangement effectively fills the slot space, increasing the slot fill factor. Furthermore, to split a single-phase winding into n equal parts and balance the back electromotive force of the split windings, the number of conductors in each of the aforementioned windings needs to be reduced to 1 / n. Reconnecting these windings with reduced conductor numbers in series forms a balanced single-phase winding divided into n groups, with the number of conductor strands or winding turns reduced to 1 / n of the original.

[0053] Although the present invention has been disclosed above with reference to embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various changes and modifications without departing from the concept and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope of the claims.

Claims

1. A stator structure for an axial flux motor, comprising: A plurality of magnetic poles and a plurality of magnetic field regions, each of which comprises a plurality of layers arranged axially along a rotation axis; and Multiple conductors form a multiphase winding; Each conductor, after traversing the lowest layer among the plurality of layers, ascends and traverses a higher layer each time it reaches the magnetic field region corresponding to the next magnetic pole, until it ascends and traverses the highest layer among the plurality of layers, such that the plurality of conductors are arranged in the same geometric order in the plurality of magnetic field regions of the plurality of magnetic poles; or Each of the conductors, after passing through the highest layer among the plurality of layers, descends and passes through the next lower layer among the plurality of layers as it crosses the magnetic field region corresponding to the next magnetic pole, until it descends and passes through the lowest layer among the plurality of layers, so that the plurality of conductors are arranged in the same geometric order in the plurality of magnetic field regions of the plurality of magnetic poles. as well as Each phase of the winding includes at least one secondary winding, and each secondary winding includes a plurality of conductors connected in series.

2. The axial flux motor stator structure as described in claim 1, wherein two plurality of secondary windings with the same geometric arrangement are connected in series by an axial connecting segment; or Two complex secondary windings with reverse geometric arrangement are connected in series with a common layer connection segment.

3. The stator structure of the axial flux motor as described in claim 2, wherein two plurality of secondary windings with the same geometric arrangement are used to transmit current along the same circumferential direction, or two plurality of secondary windings with opposite geometric arrangements are used to transmit current along two opposite circumferential directions.

4. The axial flux motor stator structure as described in claim 2, wherein the axial connecting segment connects the lowest layer and the highest layer of the plurality of layers of the plurality of secondary windings whose geometric arrangement is in the same direction.

5. The axial flux motor stator structure as described in claim 2, wherein the same-layer connecting section is located at the lowest layer or the highest layer among the plurality of layers, so as to connect the plurality of secondary windings in series.

6. The axial flux motor stator structure as claimed in claim 1, wherein each phase of the winding has a corresponding magnetic field region for each of the plurality of magnetic poles, and each magnetic field region has at least one secondary winding.

7. The stator structure of the axial flux motor as claimed in claim 1, wherein each phase of the winding has two corresponding magnetic field regions adjacent to each of the plurality of magnetic poles along a circumferential direction, and each magnetic field region has at least one secondary winding, wherein the geometric arrangement of the at least one secondary winding is in the same direction or in opposite directions.

8. The axial flux motor stator structure as claimed in claim 1, wherein each phase of the winding has at least three corresponding magnetic field regions adjacent to each of the plurality of magnetic poles along a circumferential direction, and each magnetic field region has at least one secondary winding, wherein the geometric arrangement of the at least one secondary winding is either in the same direction or in opposite directions.

9. The stator structure of the axial flux motor as claimed in claim 1, wherein a plurality of secondary windings are connected in series to form a single phase winding, each secondary winding includes N groups of conductors, each of the N groups of conductors includes a plurality of conductors with the same number of strands, and the geometric arrangement of the N groups of conductors in the plurality of magnetic field action regions corresponding to the plurality of magnetic poles is balanced relative to the rotation axis, wherein N is a positive integer greater than 1.

10. The axial flux motor stator structure as described in claim 1 further comprises a soft magnetic material body, the soft magnetic material body comprising a plurality of slots, each slot corresponding to a magnetic field action area.

11. The axial flux motor stator structure as claimed in claim 10, wherein each conductor includes a plurality of inner diameter protrusions, a plurality of receiving portions and a plurality of outer diameter protrusions, the plurality of receiving portions being located in corresponding plurality of slots, the plurality of inner diameter protrusions being located in an internal space surrounding the rotating shaft by the soft magnetic material body, and the plurality of outer diameter protrusions being exposed outside an outer diameter sidewall of the soft magnetic material body.

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