72-slot 6-pole hairpin flat wire armature winding and motor

Abstract

The application provides a 72-slot 6-pole hairpin flat wire armature winding and motor, the winding comprises a ring-shaped stator with 8 layers of 72 stator slot positions, and the winding is obtained by adopting three-phase parallel flat wire cooperation hairpin winding inside; in the U-phase winding, a first branch, a second branch and a third branch are respectively wound along the circumferential direction by layers from a first starting point in the second layer, a second starting point in the fourth layer and a third starting point in the sixth layer to a first ending point in the first layer, a second ending point in the third layer and a third ending point in the fifth layer in sequence by cooperation hairpin, and are wound and constructed along 8 layers of 72 slots; the V-phase winding and the W-phase winding are obtained by rotating 8 slots and 16 slots along the slot position increasing direction relative to the U-phase winding. The winding is beneficial to the improvement of the slot fill factor of the motor, so as to generate higher magnetic field strength, improve the motor power, and balance the potential of each branch, so that there is no circulating current problem, the winding structure is simple, and the efficiency and performance of the flat wire motor are improved.

Description

Technical Field

[0001] This invention relates to the field of motor technology, specifically to a 72-slot 6-pole hairpin flat wire armature winding and a motor. Background Technology

[0002] Because flat-wire motors significantly improve slot fill factor and motor efficiency, they are increasingly being used in new energy vehicle drive systems. However, existing flat-wire stator winding connections result in uneven current distribution along the flat copper wire cross-section at high speeds due to the skin effect and proximity effect. This leads to differences in winding resistance, causing uneven current flow and significant additional copper losses, impacting motor efficiency and weakening sustained high-speed performance. Furthermore, some stator windings are designed with complex structures to achieve current balance in parallel branches, resulting in large areas for phase and neutral wire connections, which is detrimental to stator phase and neutral wire connections. Additionally, to reduce torque ripple and improve NVH performance, short-pitch windings are now widely used in stator windings.

[0003] To address the aforementioned issues, this invention proposes a novel 72-slot 6-pole hairpin-type flat wire armature short-pitch winding and motor, which enables the phase and neutral lines of the stator winding to be in the same area, facilitating wiring, thereby improving motor efficiency and NVH performance. Summary of the Invention

[0004] Based on the above description, the present invention provides a 72-slot 6-pole hairpin flat wire armature winding and motor to solve the technical problem of uneven current flowing through each winding of the existing flat wire stator winding, which affects the efficiency and performance of the motor.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0006] In a first aspect, the present invention provides a 72-slot 6-pole hairpin-type flat wire armature winding, comprising: a ring stator with 8 layers and 72 stator slots on the inner side obtained by using three-phase parallel flat wires in conjunction with hairpins to wind through the wires;

[0007] The three phases are U phase, V phase and W phase, and the U phase winding, V phase winding and W phase winding are all formed by three branches of flat wire with hairpins.

[0008] In the U-phase winding, the first branch is formed by a flat wire starting from the first starting point on the second layer and working with a hairpin to wind around the circumference layer by layer, staggered to the first ending point on the first layer, and wound along 8 layers and 72 slots; the second branch is formed by a flat wire starting from the second starting point on the fourth layer and working with a hairpin to wind around the circumference layer by layer, staggered to the second ending point on the third layer, and wound along 8 layers and 72 slots; the third branch is formed by a flat wire starting from the third starting point on the sixth layer and working with a hairpin to wind around the circumference layer by layer, staggered to the third ending point on the fifth layer, and wound along 8 layers and 72 slots.

[0009] The V-phase winding is obtained by rotating the U-phase winding by 8 slots relative to it in the direction of increasing slot size;

[0010] The W-phase winding is obtained by rotating the U-phase winding 16 slots relative to it in the direction of increasing slot size.

[0011] Based on the above technical solution, the present invention can be further improved as follows.

[0012] Furthermore, the second and third branches are connected in the same way as the hairpins in the first branch. In each branch, every two points are paired up, and the two peeled ends of the hairpin are twisted in opposite directions and then connected to the two adjacent points respectively.

[0013] Furthermore, when using a three-phase parallel three-branch flat wire with hairpins to wind 8 layers and 72 slots, the number of poles is 6 and the number of branches is 3; define xy as the y-th layer of the x-th slot, where x∈[1, 72], y∈[a, h], a is the layer located in the slot, U1+ is the initial inflow point of the first branch current on phase U, and U1- is the final outflow point of the first branch current on phase U. The first branch of the U-phase winding is:

[0014] 61b→49c→37d→26e→14f→2g→62h→3h→15g→27f→39e→50d→62c→2b→14a→2a→62b→50c→38d→27e→15f→3g→63h→4h→16g→28f→40e→51d→63c→3b→15a→3a→63b→51c→39d→28e→16f→4g→64h→5h→17g→29f→41e→52d→64c→4b→16a→4a→64b→52c→40d→29e→17f→5g→65h→2h→14g→26f→38e→49d→61c→1b→13a→1a;

[0015] U2+ and U3+ are 61d and 62f respectively, and U2- and U3- are 1c and 2e respectively.

[0016] Furthermore, when using a three-phase parallel three-branch flat wire with hairpins to wind 8 layers and 72 slots, the number of poles is 6 and the number of branches is 3; define xy as the y-th layer of the x-th slot, where x∈[1, 72], y∈[a, h], a is the layer located in the slot, U1+ is the initial inflow point of the first branch current on phase U, and U1- is the final outflow point of the first branch current on phase U. The first branch of the U-phase winding is:

[0017] 62b→49c→38d→25e→14f→1g→62h→3h→14g→27f→38e→51d→62c→3b→14a→2a→63b→50c→39d→26e→15f→2g→63h→4h→15g→28f→39e→52d→63c→4b→15a→3a→64b→51c→40d→27e→16f→3g→64h→5h→16g→29f→40e→53d→64c→5b→16a→4a→65b→52c→41d→28e→17f→4g→65h→2h→13g→26f→37e→50d→61c→2b→13a→1a;

[0018] U2+ and U3+ are 62d and 621f respectively, and U2- and U3- are 1c and 1e respectively.

[0019] In a second aspect, the present invention also provides an electric motor, comprising: a rotor and a 72-slot 6-pole hairpin flat wire armature winding as described in any of the first aspects; the rotor being rotatable relative to the 72-slot 6-pole hairpin flat wire armature winding.

[0020] Compared with the prior art, the technical solution of this application has the following beneficial technical effects:

[0021] The 72-slot, 6-pole hairpin-type flat wire armature winding provided by this invention is obtained by winding three-phase parallel flat wires layer by layer along the circumferential direction through 8 layers and 72 slots. Each phase winding in the three-phase winding has three branches of flat wires, which are wound layer by layer through 8 layers and 72 slots according to the order of current flow in the slots, forming a 6-pole, 72-slot continuous wave winding. This provides a new continuous wave winding method. Compared with existing hairpin windings, the 72-slot, 6-pole hairpin-type flat wire armature winding provided by this invention, through the staggered winding method, is conducive to improving the slot fill factor of the motor, thereby generating a higher magnetic field strength and increasing the motor power. Moreover, it can also achieve complete current balance in each parallel branch, eliminating the circulating current problem. The winding structure is simple, the manufacturing process is good, and the efficiency and performance of the flat wire motor are improved. In addition, the phase wires and neutral wires of the stator winding are in the same area, which facilitates wiring and is suitable for mass production, providing a theoretical basis for motor stator products.

[0022] Furthermore, the motor provided by the present invention includes the above-mentioned 72-slot 6-pole hairpin flat wire armature winding, and therefore has at least all the technical effects of the above-mentioned 72-slot 6-pole hairpin flat wire armature winding, which will not be repeated here. Attached Figure Description

[0023] Figure 1 This is a diagram showing the conductor distribution within the slots of a 72-slot, 6-pole hairpin-type flat wire armature winding provided in an embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram of the U-phase winding of a 72-slot 6-pole hairpin flat wire armature winding provided in Embodiment 1 of the present invention;

[0025] Figure 3 This is a schematic diagram of the first branch winding of the U-phase of the 72-slot 6-pole hairpin flat wire armature winding provided in Embodiment 1 of the present invention;

[0026] Figure 4 This is a schematic diagram of the V-phase winding of a 72-slot 6-pole hairpin flat wire armature winding provided in Embodiment 1 of the present invention;

[0027] Figure 5 This is a schematic diagram of the W-phase winding of a 72-slot 6-pole hairpin flat wire armature winding provided in Embodiment 1 of the present invention;

[0028] Figure 6 This is a schematic diagram of the U-phase winding of the 72-slot 6-pole hairpin flat wire armature winding provided in Embodiment 2 of the present invention;

[0029] Figure 7 This is a schematic diagram of the first branch winding of the U-phase of the 72-slot 6-pole hairpin flat wire armature winding provided in Embodiment 2 of the present invention;

[0030] Figure 8 This is a schematic diagram of the V-phase winding of the 72-slot 6-pole hairpin flat wire armature winding provided in Embodiment 2 of the present invention;

[0031] Figure 9 This is a schematic diagram of the W-phase winding of the 72-slot 6-pole hairpin flat wire armature winding provided in Embodiment 2 of the present invention. Detailed Implementation

[0032] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0033] In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0034] Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention, but should not be used to limit the scope of the present invention.

[0036] The embodiment used in this invention employs an 8-layer flat wire armature winding. However, in specific implementations, the winding of even-numbered flat wire armature windings (4, 6, 10, 12, etc.) can be achieved by deleting or increasing the number of layers of cross-layer wires. Therefore, the winding method used in this invention, and the hairpin coil adapted to this method, are not limited to the winding of an 8-layer flat wire armature winding. 。

[0037] In a first aspect, embodiments of the present invention provide a 72-slot, 6-pole hairpin-type flat wire armature winding, comprising: a ring stator with 8 layers and 72 stator slots on the inner side obtained by using three-phase parallel flat wires in conjunction with hairpins to wind the winding.

[0038] The three phases are U phase, V phase and W phase. The U phase winding, V phase winding and W phase winding are all formed by three branches of flat wire with hairpins.

[0039] In the U-phase winding, the first branch is formed by a flat wire starting from the first starting point on the second layer and working with a hairpin to wind around the circumference layer by layer until the first ending point on the first layer, and is constructed along 8 layers and 72 slots; the second branch is formed by a flat wire starting from the second starting point on the fourth layer and working with a hairpin to wind around the circumference layer by layer until the second ending point on the third layer, and is constructed along 8 layers and 72 slots; the third branch is formed by a flat wire starting from the third starting point on the sixth layer and working with a hairpin to wind around the circumference layer by layer until the third ending point on the fifth layer, and is constructed along 8 layers and 72 slots.

[0040] The V-phase winding is obtained by rotating the U-phase winding 8 slots relative to the U-phase winding in the direction of increasing slot size;

[0041] The W-phase winding is obtained by rotating the U-phase winding 16 slots relative to it in the direction of increasing slot size.

[0042] The second and third branches are connected in the same way as the hairpins in the first branch. In each branch, every two points are paired up, and the two peeled ends of the hairpin are twisted in opposite directions and then connected to the two adjacent points respectively.

[0043] like Figure 1 As shown, the winding provided in this embodiment of the invention has 8 layers of slots. Taking a three-phase parallel three-branch flat wire wound through 8 layers and 72 slots as an example, the pole number is 6. Define xy as the y-th layer of the x-th slot, where x∈[1, 72], y∈[a, h], a~h are the 1-8 layer numbers of the conductor in the slot, and a is the layer located in the slot. For example, 1a refers to the a-th layer of the first stator slot. In the table, 1~64 mark the order in which the current flows through the slot, where the number 1 is the position where the current of the branch starts to flow in, i.e., U+, and the number 64 is the position where the current of the branch finally flows out, i.e., U-. That is, U1+ is the initial inflow point of the first branch current on phase U, and U1- is the final outflow point of the first branch current on phase U. The arrow lines indicate the routing of the flat wire, and the direction of the arrow is the direction of the twist. AA is the first branch of phase U, AB is the second branch of phase U, and AC is the third branch of phase U.

[0044] Example 1:

[0045] In a three-branch winding, the corresponding number of branches is 3;

[0046] Figure 2 The diagram shows the U-phase winding of a 72-slot, 6-pole hairpin-type flat wire armature winding. As shown... Figure 3 As shown, the flat wire connection route from U+ to U- in the first branch of the U-phase winding, in conjunction with the hairpin, is as follows:

[0047] 61b→49c→37d→26e→14f→2g→62h→3h→15g→27f→39e→50d→62c→2b→14a→2a→62b→50c→38d→27e→15f→3g→63h→4h→16g→28f→40e→51d→63c→3b→15a→3a→63b→51c →39d→28e→16f→4g→64h→5h→17g→29f→41e→52d→64c→4b→16a→4a→64b→52c→40d→29e→17f→5g→65h→2h→14g→26f→38e→49d→61c→1b→13a→1a; Flows in from 61b and finally flows out from 1a.

[0048] Specifically, such as Figure 3As shown, current flows in from the right end of the first hairpin, i.e., 61b. The left end of the first hairpin (arrow line AA1-AA2, AA2 end is in slot 49 of layer c, the paint stripping end is twisted to the left) and the right end of the second hairpin (arrow line AA3-AA4, i.e., AA3 end is in slot 37 of layer d and is twisted to the right towards the paint stripping end) are welded together after being twisted through the paint stripping end. That is, AA2 and AA3 are connected by welding. The left end of the second hairpin (arrow line AA3-AA4, i.e. AA4 is in slot 26 of layer e and the paint stripping end is twisted to the left) and the right end of the third hairpin (arrow line AA5-AA6, i.e. AA5 end is in slot 14 of layer f and the paint stripping end is twisted to the right) are also welded together after being twisted through the paint stripping end. That is, AA4 and AA5 are connected by welding.

[0049] The current flows from 61b (i.e., U+), through layers bc, cd, de, ef, fg, gh, hh, hg, gf, fe, ed, dc, cb, ba, aa, ab... and finally out through 1a (i.e., U-).

[0050] Correspondingly, the winding method described above can be used to wind the first branch of phase U. The span of the d-e layer at the hairpin end is 11 stator slots, and the span of the h layer at the hairpin end has two options: 9 stator slots and 13 stator slots. The remaining spans are all 12 stator slots. For the winding of the other two phases, firstly, based on the current inflow point U2+ of the second branch (AB) of phase U being 61d, the span of the second branch is similar to that of the first branch, combined with... Figure 2 The winding connection line of the second branch of phase U, which flows in from 61d and finally flows out from 1c, can be obtained. Its winding principle is the same as that of the first branch of phase U. Those skilled in the art can adapt and perform corresponding operations, which will not be elaborated here.

[0051] Similarly, the winding method of the third branch (AC) of phase U is the same as that of the first branch, only the corresponding slot is different, such as Figure 2 As shown, the winding connection line of the third branch flowing in from 62f and finally flowing out from 2e will not be described in detail here.

[0052] The V-phase winding is obtained by rotating the U-phase winding 8 slots in the direction of increasing slot number, such as... Figure 4 As shown, the first branch flows into the slot at layer b (69b) and finally flows out from the slot at layer a (9a). The second branch flows into the slot at layer d (69d) and finally flows out from the slot at layer c (9c). The third branch flows into the slot at layer f (70f) and finally flows out from the slot at layer e (10e). Those skilled in the art can perform the winding operation according to the above content. The detailed connection route will not be repeated here.

[0053] The winding method for the W-phase winding is to rotate the U-phase winding 16 slots in the direction of increasing slot number, such as... Figure 5 As shown, the first branch flows into the slot from layer b (5b) of slot 5 and flows out from layer a (17a) of slot 17. The second branch flows into the slot from layer d (5d) of slot 5 and flows out from layer c (17c) of slot 17. The third branch flows into the slot from layer f (6f) of slot 6 and flows out from layer e (18e) of slot 18. Those skilled in the art can perform the winding operation according to the above content. The detailed connection route will not be repeated.

[0054] Example 2

[0055] In a three-branch winding, the corresponding number of branches is 3;

[0056] Figure 6 The diagram shows the U-phase winding of a 72-slot, 6-pole hairpin-type flat wire armature winding. As shown... Figure 7 As shown, the flat wire connection route from U+ to U- in the first branch of the U-phase winding, in conjunction with the hairpin, is as follows:

[0057] 62b→49c→38d→25e→14f→1g→62h→3h→14g→27f→38e→51d→62c→3b→14a→2a→63b→50c→39d→26e→15f→2g→63h→4h→15g→28f→39e→52d→63c→4b→15a→3a→64b→51c→ 40d→27e→16f→3g→64h→5h→16g→29f→40e→53d→64c→5b→16a→4a→65b→52c→41d→28e→17f→4g→65h→2h→13g→26f→37e→50d→61c→2b→13a→1a; The current in this branch flows in from 62b and flows out from 1a.

[0058] Specifically, current flows in from the right end of the first hairpin, i.e., 62b. The left end of the first hairpin (arrow line AA1-AA2, AA2 end is in slot 49 of layer c, the paint stripping end is twisted to the left) and the right end of the second hairpin (arrow line AA3-AA4, i.e., AA3 end is in slot 38 of layer d and is twisted to the right towards the paint stripping end) are welded together after being twisted through the paint stripping end. That is, AA2 and AA3 are connected by welding. The left end of the second hairpin (arrow line AA3-AA4, i.e. AA4 is in slot 25 of layer e and the paint stripping end is twisted to the left) and the right end of the third hairpin (arrow line AA5-AA6, i.e. AA5 end is in slot 14 of layer f and the paint stripping end is twisted to the right) are also welded together after being twisted through the paint stripping end. That is, AA4 and AA5 are connected by welding.

[0059] The current flows from 62b (i.e., U+), through layers bc, cd, de, ef, fg, gh, hh, hg, gf, fe, ed, dc, cb, ba, aa, ab... and finally out through 1a (i.e., U-).

[0060] Correspondingly, the winding method described above can be used to wind the first branch of phase U. The span of layer a at the hairpin end is 12 stator slots, and the span of layer h at the hairpin end can be either 9 or 13 stator slots. The span of the remaining hairpin ends is 13 stator slots, and the span of all layers at the welding ends is 11 stator slots. For the winding of the other two phases, firstly, based on the current inflow point U2+ of the second branch (AB) of phase U being 62d, and the span of the second branch being the same as that of the first branch, combined with... Figure 7 The winding connection line of the second branch of phase U, which flows in from 62d and finally flows out from 1c, can be obtained. Its winding principle is the same as that of the first branch of phase U. Those skilled in the art can adapt and perform corresponding operations, which will not be elaborated here.

[0061] Similarly, the winding method of the third branch (AC) of phase U is the same as that of the first branch, only the corresponding slot is different, such as Figure 6 As shown, the winding connection line of the third branch flowing in from 62f and finally flowing out from 1e will not be described in detail here.

[0062] The V-phase winding is obtained by rotating the U-phase winding 8 slots in the direction of increasing slot number, such as... Figure 8 As shown, the first branch flows into the slot at layer b (70b) and finally flows out from the slot at layer a (9a). The second branch flows into the slot at layer d (70d) and finally flows out from the slot at layer c (9c). The third branch flows into the slot at layer f (70f) and finally flows out from the slot at layer e (9e). Those skilled in the art can perform the winding operation according to the above content. The detailed connection route will not be repeated here.

[0063] The winding method for the W-phase winding is to rotate the U-phase winding 16 slots in the direction of increasing slot number, such as... Figure 9 As shown, the first branch flows into the slot from layer b (6b) of slot 6 and flows out from layer a (17a) of slot 17. The second branch flows into the slot from layer d (6d) of slot 6 and flows out from layer c (17c) of slot 17. The third branch flows into the slot from layer f (6f) of slot 6 and flows out from layer e (17e) of slot 17. Those skilled in the art can perform the winding operation according to the above content. The detailed connection route will not be repeated.

[0064] The motor used in the above-described winding embodiment is a hairpin flat wire winding with 6 poles, 3 branches, and 72 stator slots. However, in specific implementations, different windings can be customized due to differences in the number of slots and branches. Therefore, the winding method used in this invention and the coils adapted to this winding method are not limited to the winding of the flat wire armature winding in the example.

[0065] This winding facilitates the improvement of motor slot fill factor, thereby generating a higher magnetic field strength and increasing motor power. Furthermore, the potential of each branch is balanced, eliminating circulating current issues. The winding structure is simple, has good manufacturability, and is suitable for mass production, providing a theoretical basis for motor stator products.

[0066] In a second aspect, embodiments of the present invention also provide an electric motor, comprising: a rotor and a 72-slot 6-pole hairpin flat wire armature winding as described in any embodiment of the first aspect; the rotor is rotatable relative to the 72-slot 6-pole hairpin flat wire armature winding.

[0067] Since the motor adopts the 72-slot 6-pole hairpin flat wire armature winding described in the above embodiments, and the specific structure of the 72-slot 6-pole hairpin flat wire armature winding is as described in the above embodiments, since the motor adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0068] In the description of this specification, references to terms such as "specific example" or "some examples" refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example that are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A 72-slot, 6-pole hairpin-type flat wire armature winding, characterized in that, include: It is obtained by using three-phase parallel flat wires and hairpins to wind around an annular stator with 8 layers and 72 stator slots on the inner side; The three phases are U phase, V phase and W phase, and the U phase winding, V phase winding and W phase winding are all formed by three branches of flat wire with hairpins. In the U-phase winding, the first branch is formed by a flat wire starting from the first starting point on the second layer and working with a hairpin to wind around the circumference layer by layer, staggered to the first ending point on the first layer, and wound along 8 layers and 72 slots; the second branch is formed by a flat wire starting from the second starting point on the fourth layer and working with a hairpin to wind around the circumference layer by layer, staggered to the second ending point on the third layer, and wound along 8 layers and 72 slots; the third branch is formed by a flat wire starting from the third starting point on the sixth layer and working with a hairpin to wind around the circumference layer by layer, staggered to the third ending point on the fifth layer, and wound along 8 layers and 72 slots. The V-phase winding is obtained by rotating the U-phase winding by 8 slots relative to it in the direction of increasing slot size; The W-phase winding is obtained by rotating the U-phase winding 16 slots relative to it in the direction of increasing slot size; The second and third branches are connected in the same way as the hairpin in the first branch. In each branch, every two points are paired up, and the two peeled ends of the hairpin are twisted in opposite directions and then connected to the two adjacent points respectively. When using a three-phase parallel three-branch flat wire with hairpins to wind 8 layers and 72 slots, the number of poles is 6 and the number of branches is 3; define xy as the y-th layer of the x-th slot, where x∈[1, 72], y∈[a, h], a is the layer located in the slot, U1+ is the initial inflow point of the first branch current on phase U, and U1- is the final outflow point of the first branch current on phase U. The first branch of the U-phase winding is: 61b→49c→37d→26e→14f→2g→62h→3h→15g→27f→39e→50d→62c→2b→14a→2a→62b→50c→38d→27e→15f→3g→63h→4h→16g→28f→40e→51d→63c→3b→15a→3a→63b→51c→39d→28e→16f→4g→64h→5h→17g→29f→41e→52d→64c→4b→16a→4a→64b→52c→40d→29e→17f→5g→65h→2h→14g→26f→38e→49d→61c→1b→13a→1a; U2+ and U3+ are 61d and 62f respectively, and U2- and U3- are 1c and 2e respectively; Alternatively, the first branch of the U-phase winding is: 62b→49c→38d→25e→14f→1g→62h→3h→14g→27f→38e→51d→62c→3b→14a→2a→63b→50c→39d→26e→15f→2g→63h→4h→15g→28f→39e→52d→63c→4b→15a→3a→64b→51c→40d→27e→16f→3g→64h→5h→16g→29f→40e→53d→64c→5b→16a→4a→65b→52c→41d→28e→17f→4g→65h→2h→13g→26f→37e→50d→61c→2b→13a→1a; U2+ and U3+ are 62d and 62f respectively, and U2- and U3- are 1c and 1e respectively.

2. An electric motor, characterized in that, include: The rotor and the 72-slot 6-pole hairpin flat wire armature winding as described in claim 1; the rotor is rotatable relative to the 72-slot 6-pole hairpin flat wire armature winding.

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