Flat wire motor

Abstract

This invention discloses a flat wire motor, comprising a stator core with a plurality of stator slots, wherein a three-phase multi-layer flat wire winding is embedded in the stator slots. Each phase multi-layer flat wire winding is installed in the stator core slot and includes at least two layers of concentrically arranged sub-windings, with the support legs of the sub-windings located in adjacent Nth and N+1th layers, where N is an odd number. Each sub-winding includes a first conductor group and a second conductor group offset by one magnetic pole position in the circumferential direction. A long-pitch series connector with a pitch of Y+1 is connected in series between the first conductor groups of adjacent two layers of sub-windings, and a short-pitch series connector with a pitch of Y-1 is connected in series between the second conductor groups of adjacent two layers of sub-windings. The flat wire motor of this invention has advantages such as ingenious structural design, reduced multi-layer bridging connectors, and facilitates product serialization and shortens the R&D cycle.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet motor technology, and in particular to a flat wire motor. Background Technology

[0002] With the surge in demands for torque and power density in new energy vehicle drive motors, drive motors are increasingly adopting flat wire windings. Using flat wire in the stator windings significantly increases slot fill factor and improves heat dissipation within the slots. Flat wire windings typically employ wave windings, allowing for different pitches to meet requirements for winding arrangement and insulation. Common flat wire stator winding structures include Hairpin, I-pin, and continuous wave windings, with the first two being the most mature. The number of flat wire layers in stator windings varies depending on the complexity of the manufacturing process, ranging from 2 to 12 layers. Existing multi-layer flat wire windings often require at least one type of hairpin with two legs bridging more than three layers to allow for interconnection between hairpins belonging to the same phase, thus increasing the variety of hairpins. Furthermore, different winding layer counts necessitate redesign, resulting in long development cycles and hindering standardization. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is: how to provide a flat wire motor with a clever structural design that reduces the number of multi-layer jumper clips, facilitates product serialization, and shortens the research and development cycle.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] A flat wire motor includes a stator core with a plurality of stator slots, characterized in that a three-phase multi-layer flat wire winding is embedded in the stator slots, each phase of the multi-layer flat wire winding includes at least two layers of concentrically arranged sub-windings, the legs of the sub-windings being located in adjacent Nth and N+1th layers, where N is an odd number; each sub-winding includes a first conductor group and a second conductor group arranged circumferentially offset by one magnetic pole position, the first conductor group including two conductor rings arranged circumferentially offset by one slot and a short-pitch U-shaped conductor connected in series between the two conductor rings; the second conductor group including two conductor rings arranged circumferentially offset by one slot and a long-pitch U-shaped conductor connected in series between the two conductor rings. The conductor ring comprises p-1 standard U-shaped conductors connected in series circumferentially, with a magnetic pole position between each two connected standard U-shaped conductors, where p is the number of magnetic pole pairs; the pitch of the standard U-shaped conductors is Y, the pitch of the short-pitch U-shaped conductors is Y-1, and the pitch of the long-pitch U-shaped conductors is Y+1; ​​a long-pitch series hairpin with a pitch of Y+1 is connected in series between the first conductor groups of two adjacent layers of the sub-winding, and the legs of the long-pitch series hairpin are located in the adjacent N+1 and N+2 layers; a short-pitch series hairpin with a pitch of Y-1 is connected in series between the second conductor groups of two adjacent layers of the sub-winding, and the legs of the short-pitch series hairpin are located in the adjacent N+1 and N+2 layers.

[0006] In the above structure, each sub-winding layer occupies two adjacent layers in the stator slot, and at least two layers of sub-windings are concentrically arranged. For a multi-layer flat wire winding with k (k≥2) layers of sub-windings, the number of flat wire layers in the stator slot is 2k layers, i.e., an even number of layers of 4 or more. The first conductor groups of two adjacent sub-winding layers are connected by long-pitch series hairpins, and the second conductor groups of two adjacent sub-winding layers are connected by short-pitch series hairpins, so that all the first conductor groups are connected in series with each other, and all the second conductor groups are connected in series with each other. Since the sub-winding occupies two layers in the stator slot, the two legs of the hairpins constituting the first and second conductor groups of the sub-winding are also located in two adjacent layers. The long-pitch series hairpins connected to two adjacent first conductor groups and the short-pitch series hairpins connected to two adjacent second conductor groups occupy two adjacent layers between two adjacent sub-windings. That is, the two legs of all hairpins are in two adjacent layers, reducing the types of hairpins and lowering the processing cost. Moreover, multi-layer windings only require increasing the number of concentric sub-winding layers, and then connecting them in series using long-pitch and short-pitch series connectors. No redesign is required, the design cycle is short, and it is easy to achieve product serialization design.

[0007] Furthermore, a reverse conductor is connected in series between the first conductor group and the second conductor group of the sub-winding located in the innermost or outermost layer.

[0008] In this way, by connecting a reverse conductor in series between the first and second conductor groups of the innermost or outermost layer, the current enters from the first conductor group of the innermost or outermost sub-winding, flows sequentially through adjacent first conductor groups in the same direction through long-distance series connectors, and then is connected to the second conductor group of the outermost or innermost sub-winding by the reverse conductor. After entering the second conductor group through the reverse conductor, the current reverses direction around the stator, and then flows sequentially through adjacent second conductor groups in the same direction through short-distance series connectors, thus realizing the series connection of a branch.

[0009] Furthermore, the reverse conductor includes two first S-shaped conductors with the same twisting direction and both located in the innermost or outermost layer. The first S-shaped conductor includes a groove inside the iron core slot and welding ends and plug ends twisted in opposite directions at both ends inside the groove. A jumper conductor is connected in series between the plug ends of the two first S-shaped conductors.

[0010] Furthermore, the reverse conductor is a U-shaped conductor with both legs located in the outermost or innermost layer. The U-shaped conductor includes two slots inside the iron core slots, and welding ends and insertion ends at both ends of the corresponding slots twisted in opposite directions. The two insertion ends inside the slots are twisted in the same direction and connected by an integrally formed conductor.

[0011] Furthermore, at the other end of the first conductor group and the second conductor group of the sub-winding located in the innermost or outermost layer, a second S-shaped conductor is connected. The second S-shaped conductor includes a slot inside the iron core groove, and a welding end and a plug end twisted in opposite directions at both ends inside the slot. The twisting directions of the welding ends of the two second S-shaped conductors are the same.

[0012] Furthermore, the span between the two slots of the reverse conductor is Y+nQ / p or Y+nQ / p+2; the span between the two slots of the second S-shaped conductor is Y+nQ / p+2 or Y+nQ / p, where 0≤n≤p and Q is the total number of slots.

[0013] Furthermore, each phase of the multilayer flat wire winding includes two concentric sub-windings, the span between the two slots of the reverse conductor is Y or Y+2; the span between the slots of the two second S-shaped conductors is Y+2 or Y.

[0014] Furthermore, a third S-shaped conductor is connected in series to both the first conductor group located in the outermost or innermost layer and the second conductor group located in the innermost or outermost layer. The third S-shaped conductor includes a groove inside the iron core slot, and a welding end and a plug end twisted in opposite directions at both ends inside the groove. The welding ends of the two third S-shaped conductors are respectively connected in series to the corresponding first conductor group or second conductor group, and the plug ends are connected in parallel.

[0015] In this way, all the first conductor groups are connected in series to form one branch, all the second conductor groups are connected in series to form another branch, and the two branches are connected in parallel through the third S-shaped conductor. In this way, for the two-branch phase windings of the multi-layer flat wire structure, the multi-layer sub-windings can also be expanded by long-pitch series hairpins and short-pitch series hairpins to achieve serialization.

[0016] Furthermore, the standard U-shaped conductor, short-pitch U-shaped conductor, long-pitch U-shaped conductor, long-pitch serial hairpin, and short-pitch serial hairpin are all split-pull hairpin conductors.

[0017] In this way, since all the hairpins' feet are within two adjacent layers, the only difference between the hairpins is the span between them. By using the splitting forming process, a single splitting forming machine can be used with different parameters to directly split and form the hairpins without having to readjust the equipment. This helps to save production costs and improve production efficiency.

[0018] In summary, the flat wire motor of the present invention has the advantages of ingenious structural design, reduced multi-layer bridging, facilitates product serialization, and shortens the research and development cycle. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the stator structure in Example 1.

[0020] Figure 2 for Figure 1 A schematic diagram of the structure of a multi-layer flat wire winding.

[0021] Figure 3 This is a schematic diagram of a single-phase multi-layer flat wire winding.

[0022] Figure 4 for Figure 3 A schematic diagram of the exploded structure of the two-layer sub-winding.

[0023] Figure 5 for Figure 4 A schematic diagram of the exploded structure of the outer and middle sub-windings.

[0024] Figure 6 for Figure 5 A schematic diagram of the exploded structure of the first conductor group in the middle.

[0025] Figure 7 for Figure 5 A schematic diagram of the exploded structure of the second conductor group in the middle.

[0026] Figure 8 A schematic diagram of the exploded structure of the first conductor group arranged in series.

[0027] Figure 9 A schematic diagram of the exploded structure of the second conductor group arranged in series.

[0028] Figure 10 This is a schematic diagram of the structure of the reverse conductor 26.

[0029] Figure 11 This is a schematic diagram of another structure for the reverse conductor 26.

[0030] Figure 12 This is a simplified diagram of the flat wire hair clip connection in this embodiment.

[0031] Figure 13 This is a simplified connection diagram for a six-line, one-branch flat wire hairpin.

[0032] Figure 14 This is a schematic diagram of the structure of a single-phase multilayer flat wire winding in Example 2. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the embodiments.

[0034] Example 1:

[0035] like Figure 1 and Figure 2 As shown, a flat wire motor includes a stator core 10 and a multi-layer flat wire winding 20. The stator core 10 has a plurality of core slots 11 arranged circumferentially at predetermined slot spacings. The multi-layer flat wire winding 20 passes through the core slots 11 and is three-phase.

[0036] In this embodiment, each phase of the multilayer flat wire winding 20 includes two concentrically arranged sub-windings 2, the legs of which are located in adjacent layers N and N+1, where N is an odd number; for example Figure 3 and Figure 4 As shown, the legs of the outer sub-winding 2 are located in the adjacent first and second layers (from the outside to the inside), and the legs of the inner sub-winding 2 are located in the adjacent third and fourth layers (from the outside to the inside).

[0037] like Figure 4 and Figure 5 As shown, each of the sub-windings 2 includes a first conductor group 21 and a second conductor group 22 that are offset by one magnetic pole position in the circumferential direction. The first conductor group 21 includes two conductor rings 23 that are offset by one slot in the circumferential direction and a short-pitch U-shaped conductor 24 connected in series between the two conductor rings 23, as shown. Figure 6 As shown. The second conductor group 22 includes two conductor rings 23 offset by one slot in the circumferential direction and a long-spacing U-shaped conductor 25 connected in series between the two conductor rings 23, as shown. Figure 7As shown. The conductor ring 23 includes p-1 standard U-shaped conductors connected in series circumferentially, with a magnetic pole position between each pair of standard U-shaped conductors connected in series, where p is the number of magnetic pole pairs; the pitch of the standard U-shaped conductors is Y, the pitch of the short-pitch U-shaped conductor 24 is Y-1, and the pitch of the long-pitch U-shaped conductor 25 is Y+1; ​​as Figure 6 and Figure 7 As shown, in this embodiment, the number of magnetic pole pairs is 4, and the conductor ring 23 is composed of 3 standard U-shaped conductors connected in series in the circumferential direction.

[0038] like Figure 8 As shown, a long-pitch series hairpin 27 with a pitch of Y+1 is connected in series between the first conductor group 21 of the two adjacent sub-windings 2. The legs of the long-pitch series hairpin 27 are located in the adjacent N+1 and N+2 layers.

[0039] like Figure 9 As shown, a short-pitch tandem hairpin 28 with a pitch of Y-1 is connected in series between the second conductor group 22 of the adjacent two layers of the sub-winding 2. The legs of the short-pitch tandem hairpin 28 are located in the adjacent N+1 and N+2 layers.

[0040] In this embodiment, since the sub-winding 2 is provided with two layers, the adjacent layers of the two sub-windings are the second layer and the third layer, that is, the two legs of the long-pitch series hairpin 27 and the two legs of the short-pitch series hairpin 28 are located in the second layer and the third layer respectively.

[0041] In addition, such as Figure 3 , Figure 8 and Figure 9 As shown, a reverse conductor 26 is connected in series between the first conductor group 21 and the second conductor group 22 of the innermost sub-winding 2.

[0042] In this embodiment, the reverse conductor 26 is a U-shaped conductor with both legs located in the innermost layer, such as... Figure 10 As shown, the U-shaped conductor includes two slot interiors 31 passing through the iron core slot 11, and welding ends 32 and insertion ends 33 at both ends of the corresponding slot interiors 31 that are twisted in opposite directions; the insertion ends 33 of the two slot interiors 31 are twisted in the same direction and connected by an integrally formed conductor, and the span between the two slot interiors 31 of the reverse conductor 26 is Y, i.e., n=0.

[0043] Of course, in specific implementations, the reverse conductor 26 can also be used as follows: Figure 11The structure shown includes two first S-shaped conductors 261 with the same twisting direction and both located in the innermost or outermost layer. The first S-shaped conductor includes a groove interior 31 that passes through the iron core groove 11, and welding ends 32 and plug ends 33 that are twisted in opposite directions and disposed at both ends of the groove interior 31. A bridging conductor 262 is connected in series between the plug ends 33 of the two first S-shaped conductors.

[0044] In this embodiment, the other ends of the first conductor group 21 and the second conductor group 22 of the outermost sub-winding 2 are each connected to a second S-shaped conductor. The second S-shaped conductor includes a slot interior 31 that passes through the iron core slot 11, and welding ends 32 and plug ends 33 that are twisted in opposite directions at both ends of the slot interior 31. The twisting directions of the welding ends 32 of the two second S-shaped conductors are the same, and the span of the slot interior 31 of the two second S-shaped conductors is Y+2, that is, n=0.

[0045] In specific implementation, the reverse conductor 26 can be placed in the outermost layer, and the span of the groove 31 is Y+2; the two second S-shaped conductors can be placed in the innermost layer, and the span of the groove 31 is Y.

[0046] In addition, in specific implementation, the inner sub-winding can be rotated 2n magnetic pole positions relative to the outer sub-winding in the circumferential direction, where 0≤n≤p, and p is the number of magnetic pole pairs. In this way, the position of one leg (on the outer sub-winding) of the reverse conductor 26 remains unchanged, while the other leg (on the inner sub-winding) moves relative to it in the circumferential direction by nQ / p slots. That is, the span of the reverse conductor 26 changes from Y in this embodiment to Y+nQ / p. Similarly, the span of the slots 31 of the corresponding two second S-shaped conductors is Y+nQ / p+2.

[0047] Meanwhile, in this embodiment, the standard U-shaped conductor, short-pitch U-shaped conductor 24, long-pitch U-shaped conductor 25, long-pitch serial hairpin 27 and short-pitch serial hairpin 28 are all split-type hairpin conductors.

[0048] In this way, since all the hairpins' feet are within two adjacent layers, the only difference between the hairpins is the span between them. By using the splitting forming process, a single splitting forming machine can be used with different parameters to directly split and form the hairpins without having to readjust the equipment. This helps to save production costs and improve production efficiency.

[0049] like Figure 12As shown in the figure, from top to bottom, the first layer sub-winding and the second layer sub-winding are arranged from the outside to the inside. The left side of the figure is the first conductor group, and the right side is the second conductor group. It can be seen from the figure that the current enters from the first conductor group of the first layer sub-winding, flows in the first conductor group in the counterclockwise direction of the winding (viewed from the top), and then enters the first conductor group of the second layer sub-winding after passing through the long-pitch series hairpin 27 and continues to flow in the counterclockwise direction. Then, it enters the second conductor group of the second layer sub-winding through the reverse conductor 26. After entering the second conductor group, the current flows in the clockwise direction. Then, it enters the second conductor group of the first layer sub-winding after passing through the short-pitch series hairpin 28 and continues to flow in the clockwise direction, forming a four-wire branch circuit.

[0050] For a six-layer flat wire winding, only one additional sub-winding layer is needed to form a six-wire branch circuit, such as... Figure 13 As shown.

[0051] Example 2:

[0052] The main difference from Example 1 is that: Figure 14 As shown, a third S-shaped conductor 29 is connected in series to both the first conductor group located in the outermost or innermost layer and the second conductor group located in the innermost or outermost layer. The third S-shaped conductor 29 includes a groove interior 31 that passes through the iron core groove 11, and a welding end 32 and a plug end 33 that are twisted in opposite directions at both ends of the groove interior 31. The welding ends of the two third S-shaped conductors 29 are respectively connected in series to the corresponding first conductor group or second conductor group, and the plug ends 33 are arranged in parallel.

[0053] In this way, all the first conductor groups are connected in series to form one branch, all the second conductor groups are connected in series to form another branch, and the two branches are connected in parallel through the third S-shaped conductor. In this way, for the two-branch phase windings of the multi-layer flat wire structure, the multi-layer sub-windings can also be expanded by long-pitch series hairpins and short-pitch series hairpins to achieve serialization.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A flat wire motor, comprising a stator core having a plurality of stator slots, characterized in that, The stator slots are embedded with three-phase multi-layer flat wire windings. Each phase of the multi-layer flat wire winding includes at least two concentric sub-windings (2). The legs of the sub-windings (2) are located in adjacent Nth and N+1th layers, where N is an odd number. Each sub-winding (2) includes a first conductor group (21) and a second conductor group (22) offset by one magnetic pole position in the circumferential direction. The first conductor group (21) includes two conductor rings (23) offset by one slot in the circumferential direction and a short-pitch U-shaped conductor (24) connected in series between the two conductor rings (23). The second conductor group (22) includes two conductor rings (23) offset by one slot in the circumferential direction and a long-pitch U-shaped conductor (25) connected in series between the two conductor rings (23). The conductor rings (23) It includes p-1 standard U-shaped conductors connected in series in the circumferential direction, with a magnetic pole position between two standard U-shaped conductors connected in series, where p is the number of magnetic pole pairs; the pitch of the standard U-shaped conductor is Y, the pitch of the short-pitch U-shaped conductor (24) is Y-1, and the pitch of the long-pitch U-shaped conductor (25) is Y+1; ​​a long-pitch series hairpin (27) with a pitch of Y+1 is connected in series between the first conductor group (21) of two adjacent layers of the sub-winding (2), and the legs of the long-pitch series hairpin (27) are located in the adjacent N+1 and N+2 layers; a short-pitch series hairpin (28) with a pitch of Y-1 is connected in series between the second conductor group (22) of two adjacent layers of the sub-winding (2), and the legs of the short-pitch series hairpin (28) are located in the adjacent N+1 and N+2 layers.

2. The flat wire motor as described in claim 1, characterized in that, A reverse conductor (26) is connected in series between the first conductor group (21) and the second conductor group (22) of the sub-winding (2) located in the innermost or outermost layer.

3. The flat wire motor as described in claim 2, characterized in that, The reverse conductor (26) includes two first S-shaped conductors (261) with the same twist direction and both located in the innermost or outermost layer. The first S-shaped conductor includes a groove (31) passing through the iron core groove (11), and welding ends (32) and plug ends (33) twisted in opposite directions at both ends of the groove (31); a jumper conductor (262) is connected in series between the plug ends (33) of the two first S-shaped conductors.

4. The flat wire motor as described in claim 2, characterized in that, The reverse conductor (26) is a U-shaped conductor with both legs located in the outermost or innermost layer. The U-shaped conductor includes two slot interiors (31) passing through the iron core slot (11), and welding ends (32) and plug ends (33) at both ends of the corresponding slot interiors (31) twisted in opposite directions. The plug ends (33) of the two slot interiors (31) are twisted in the same direction and connected by an integrally formed conductor.

5. The flat wire motor as described in claim 3 or 4, characterized in that, The other end of the first conductor group (21) and the second conductor group (22) of the sub-winding (2) located in the innermost or outermost layer is connected to a second S-shaped conductor. The second S-shaped conductor includes a slot interior (31) passing through the iron core slot (11), and a welding end (32) and a plug end (33) twisted in opposite directions at both ends of the slot interior (31); the welding ends (32) of the two second S-shaped conductors are twisted in the same direction.

6. The flat wire motor as described in claim 5, characterized in that, The span between the two slots (31) of the reverse conductor (26) is Y+nQ / p or Y+nQ / p+2; the span between the two slots (31) of the second S-shaped conductor is Y+nQ / p+2 or Y+nQ / p, where 0≤n≤p and Q is the total number of slots.

7. The flat wire motor as described in claim 5, characterized in that, Each phase of the multi-layer flat wire winding includes two concentric sub-windings (2), the span of the two slots (31) of the reverse conductor (26) is Y or Y+2; the span of the slots (31) of the two second S-shaped conductors is Y+2 or Y.

8. The flat wire motor as described in claim 1, characterized in that, A third S-shaped conductor (29) is connected in series to both the first conductor group located in the outermost or innermost layer and the second conductor group located in the innermost or outermost layer. The third S-shaped conductor (29) includes a groove (31) passing through the iron core groove (11), and a welding end (32) and a plug end (33) twisted in opposite directions at both ends of the groove (31). The welding ends of the two third S-shaped conductors (29) are respectively connected in series to the corresponding first conductor group or second conductor group, and the plug ends (33) are connected in parallel.

9. The flat wire motor as described in claim 1, characterized in that, The standard U-shaped conductor, short-pitch U-shaped conductor (24), long-pitch U-shaped conductor (25), long-pitch serial hairpin (27) and short-pitch serial hairpin (28) are all split-type hairpin conductors.

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