Patent Description:
With increasingly vigorous development of electric automobiles, a power density of a motor of the electric automobile is higher and higher. Compared with a round wire motor, a flat wire motor has a higher space filling factor. Improvement of the space filling factor means that filling with more copper wires can be realized on the premise of no change of space, a more powerful magnetic field can be generated, and the power density can be further improved.

The flat wire motor includes a rotor and a flat wire stator, and the flat wire stator includes an iron core and a flat wire winding. A winding mode of the flat wire winding may have an influence on performance, process and the like of the flat wire motor. The flat wire winding in the flat wire motor is formed by welding hair-pin flat wires inserted into iron core slots, the adopted hair-pin flat wires have the same structure, process difficulty can be reduced, production efficiency is improved, and the more the varieties of adopted hair-pin flat wires are, the lower the production efficiency becomes.

In the related art, during wire winding of the flat wire winding, firstly, wire winding is performed in the plurality of iron core slots in a circumferential direction of the iron core to form a winding layer, and then the flat wire is spanned to another layer to be again wound in the plurality of iron core slots in the circumferential direction of the iron core so as to form another winding layer till it reaches the needed quantity of layers. This winding method requires a large variety of hairpin flat wires, resulting in low production efficiency.

<CIT> discloses a rotary electric machine that includes a stator that has a plurality of slots accommodating a coil having a lap winding configuration made of a segment conductor, and a rotor that faces the stator and has a plurality of magnetic poles, and has a fractional slot configuration in which the number of slots per pole and phase is more than <NUM>/<NUM>, and a denominator is equal to or more than <NUM> in an irreducible fraction expression. When the irreducible fraction expression of the number of slots per pole and phase is set as (a+b/c) where a indicates zero or a positive integer, and b and c indicate a positive integer and b<c, the coil for a laps is configured by an adjacent pole coil group, and the coil of a (a+<NUM>)th lap is configured by a continuous-pole coil group. The a laps are made in the same direction.

<CIT> discloses a stator assembly and a motor. The stator assembly comprises a stator core and a stator winding. The stator core is provided with a plurality of stator slots which are distributed along the circumferential direction of the stator core. Each phase of first winding of the stator winding comprises a first winding part and a plurality of second winding parts, and each phase of second winding of the stator winding comprises a third winding part and a plurality of fourth winding parts.

<CIT> describes a motor and a flat wire a motor winding. The winding comprises a stator, a plurality of stator goofs being formed in the stator, M layers of conductors being arranged in each stator goof and calls sequentially stacked and embedded from the first layer to the M th layer of each conductor.

<CIT> describes an armature comprising a slots, including a first slot in which only a first binding that constitutes one phase among three phases is disclosed, then a second slot provided neighboring the first slot in the circumferential direction in which the first binding and a second binding that constitutes a different phase among the three phases from the phase constituted by the first binding are disclosed. In the first slot, accommodated parts have the first binding are disposed in a role in the radial direction. In the second slot, accommodated parts of the first binding and accommodated parts of the second binding all alternately disposed in a role in the radial direction.

Examples of the disclosure provide a flat wire stator and a motor, and it is conducive to improving the production efficiency of a flat wire motor. The technical solution is as follows.

According to a first aspect of the disclosure, a flat wire stator is provided, the flat wire includes an iron core and a flat wire winding;.

the iron core has a plurality of iron core slots;.

the flat wire winding includes a first phase winding, the first phase winding includes a plurality of coils, the plurality of coils are distributed in rotational symmetry around an axis of the iron core, the coils are wound in some iron core slots of the plurality of the iron core slots, first ends and second ends of the coils are located at the same end of the iron core, the first ends are located on the sides of the iron core slots close to the axis of the iron core, and the second ends are located on the sides of the iron core slots away from the axis of the iron core;.

the plurality of coils are connected in series in sequence, the first end of a coil is connected to the first end of one coil of two coils adjacent to the coil, and the second end of the coil is connected to the second end of the other coil of the two coils adjacent to the coil.

The coils include a plurality of branches, and the plurality of branches in the same coil are arranged by offset of one iron core slot in sequence in a circumferential direction of the iron core;.

Optionally, in the plurality of first jumper wires connecting the adjacent coils, spans of the plurality of first jumper wires are equal.

Optionally, in the plurality of second jumper wires connecting the adjacent coils, spans of the plurality of second jumper wires are equal.

Optionally, in the plurality of second jumper wires connecting the adjacent coils, a span of at least one second jumper wire is larger than spans of the other second jumper wires.

Optionally, the same coil includes Z branches, Z is an integer no smaller than <NUM>, in the plurality of second jumper wires connecting the adjacent coils, the span of the second jumper wire with the largest span is k+Z, each of the spans of the other second jumper wires is k, and k is a positive integer.

Optionally, each branch plurality of branches includes a first sub-coil and a second sub-coil connected to each other, and the first sub-coil is located on one side of the second sub-coil close to the axis of the iron core; and
the first sub-coil is wound in the two iron core slots which are mutually spaced, the second sub-coil is wound in the other two iron core slots which are mutually spaced, the two iron core slots where the second sub-coil is located are offset by one iron core slot in the same direction respectively relative to the two iron core slots where the first sub-coil is located.

Optionally, the quantity of the iron core slots is 18p, p is the number of pole-pairs, the quantity of turns of the coils in each iron core slot is <NUM>, and m is a positive integer.

Optionally, the flat wire winding further includes a second phase winding and a third phase winding, and the first phase winding, the second phase winding and the third phase winding are distributed in rotational symmetry around the axis of the iron core.

According to a second aspect of the disclosure, a motor is provided, the motor includes a rotor and the flat wire stator according to the first aspect of the disclosure. beneficial effects brought by the technical solution provided by the example of the disclosure at least include:
by arranging the winding of the same phase in a mode of including the plurality of coils connected in series in sequence, the plurality of coils are distributed in rotational symmetry around the axis of the iron core, the coils are wound in a part of the iron core slots, the first ends and the second ends of the coils are located on the sides of the iron core slots close to the axis of the iron core and on the sides of the iron core slots away from the axis of the iron core, respectively, that is, extending from the first ends of the coils to the second ends, a plurality of layers of windings are formed gradually instead of forming a layer of winding and then crossing to another layer to form another layer of winding, arranging an additional flat wire conductor for crossing from one layer to another layer is not needed, thus the varieties of the adopted hair-pin flat wires during wire winding can be reduced, and the production efficiency can be improved.

It should be understood that the above general description and the following detailed description are only illustrative and explanatory, and may not limit the disclosure.

In order to describe technical solutions in the examples of the disclosure more clearly, the accompanying drawings needed in the description of the examples will be briefly introduced below. The accompanying drawings in the following description are merely some examples of the disclosure. Those ordinarily skilled in the art can further obtain other accompanying drawings according to these accompanying drawings without creative work.

In order to make objectives, technical solutions and advantages of the disclosure clearer, implementations of the disclosure will be further described in detail below with reference to the accompanying drawings.

Unless otherwise defined, technical or scientific terms used herein should be commonly understood by those ordinarily skilled in the art to which the disclosure belongs. "First", "second", "third" and similar words used in the specification and claims of the patent application of the disclosure do not represent any sequence, quantity or significance but merely intend to distinguish different components. Likewise, "one" or "a/an" and similar words do not represent quantity limit but represent "at least one". "Include" or "contain" and similar words mean that an element or item preceding "include" or "contain" covers an element or an item and its equivalents listed after "include" or "contain" without excluding other elements or items. "Connected" or "connection" and similar words are not limited to a physical or mechanical connection, but may include an electrical connection, direct or indirect. "Up", "down", "left", "right" and the like are merely used for representing a relative position relation, and if an absolute position of a described object changes, the related position relation may also change correspondingly.

There are varieties of hair-pin flat wires needed in the winding mode in the related art, which results in the lower production efficiency.

<FIG> is a schematic structural diagram of a flat wire stator provided by an example of the disclosure. As shown in <FIG>, the flat wire stator includes an iron core <NUM> and a flat wire winding <NUM>.

<FIG> is a schematic diagram of an end surface of an iron core provided by an example of the disclosure. As shown in <FIG>, the iron core <NUM> has a plurality of iron core slots 10a. The iron core <NUM> is cylindric, and the plurality of iron core slots 10a are distributed on an inner side wall of the iron core <NUM> in a circumferential direction of the iron core <NUM>. The iron core slots 10a are configured to wind the flat wire winding <NUM>.

<FIG> is a schematic expanded view of a flat wire winding provided by an example of the disclosure. What is shown in the figure is an expanded end surface of the iron core <NUM> after cutting along a dotted line A in <FIG>. Each column in the figure represents an iron core slot 10a. For convenience of understanding, the plurality of iron core slots 10a are marked with Arabic numerals, respectively, the iron core slots 10a marked by <NUM>, <NUM>, <NUM> and <NUM> are repeatedly shown, and a side with marks of <NUM> to <NUM> is an inner side of the iron core <NUM>. In the figure, "o" represents a flat wire conductor extending from a paper surface to outside in the iron core slots 10a, "×" represents a flat wire conductor extending from the paper surface to inside, and a line connecting "∘" and "×" represents a flat wire conductor located outside the iron core slots 10a. As shown in <FIG>, the flat wire winding <NUM> includes a first phase winding <NUM>.

For example, as for a three-phase motor, the flat wire winding <NUM> further includes a second phase winding and a third phase winding, and the first phase winding <NUM>, the second phase winding and the third phase winding are distributed in rotational symmetry around an axis of the iron core <NUM>. The first phase winding <NUM>, the second phase winding and the third phase winding have the same structure, the line connecting "∘" and "×" shown in <FIG>, and "∘" and "×" connected by the line constitute the first phase winding <NUM>. The rest of "o" and "×" in the figure are connected by a line with reference to the first phase winding <NUM>, so the second phase winding and the third phase winding are obtained. The example of the disclosure is described by taking the structure of the first phase winding <NUM> as an example.

The first phase winding <NUM> includes a plurality of coils <NUM>. <FIG> is a schematic partial enlargement view of <FIG>. One coil <NUM> is shown in <FIG>. Combining with <FIG>, the plurality of coils <NUM> are distributed in rotational symmetry around an axis of the iron core <NUM>, and the coils <NUM> are wound in some iron core slots 10a in the plurality of iron core slots 10a. A first end and a second end of the coil <NUM> are located at the same end of the iron core <NUM>, the first end is located on a side, namely, an upper side of <FIG>, of the iron core slot 10a close to the axis of the iron core <NUM>, and the second end is located on a side, namely, a lower side of <FIG>, of the iron core slot 10a away from the axis of the iron core <NUM>.

<FIG> is a schematic partial enlargement view of <FIG>. As shown in <FIG>, the plurality of coils <NUM> are connected in series in sequence, the first end of a coil <NUM> is connected to the first end of one coil <NUM> of two coils <NUM> adjacent to the coil, and the second end of the coil <NUM> is connected to the second end of the other coil <NUM> of the two coils <NUM> adjacent to the coil.

By arranging the winding in the same phase in a mode of including the plurality of coils connected in series in sequence, the plurality of coils are distributed in rotational symmetry around the axis of the iron core, the coils are wound in a part of the iron core slots, the first ends and the second ends of the coils are located on the sides of the iron core slots close to the axis of the iron core and on the sides of the iron core slots away from the axis of the iron core, respectively, that is, extending from the first ends of the coils to the second ends, a plurality of layers of windings are formed gradually instead of forming a layer of winding and then crossing to another layer to form another layer of winding, arranging an additional flat wire conductor for crossing from one layer to another layer is not needed, thus the varieties of the adopted hair-pin flat wires during wire winding can be reduced, and the production efficiency can be improved.

Optionally, the quantity of the iron core slots 10a is 18p, p is the number of pole-pairs, and the quantity of turns of the coils <NUM> in each iron core slot 10a is <NUM>, and m is a positive integer.

The coil <NUM> is formed by flat wire conductors, for example, a copper flat wire. The quantity of turns of the coils <NUM> in each iron core slot 10a is the quantity of layers of the flat wire conductors contained in the same iron core slot 10a.

An insulation material, for example, insulation resin, is arranged in the iron core slots 10a, so as insulate the flat wire winding <NUM> from the iron core <NUM>.

As for different motors, a value of p and a value of m may differ. The value of p and the value of m may be set according to a demand for performance of the motors. The example of the disclosure makes description by taking p=<NUM> and m=<NUM> as an example, that is, the iron core <NUM> has <NUM> iron core slots 10a. For convenience of description, in the circumferential direction of the iron core <NUM>, the <NUM> iron core slots 10a are numbered in sequence, as shown in <FIG>. <FIG> is a schematic partial enlargement view of <FIG>. As shown in <FIG>, the quantity of turns of the coils <NUM> in each iron core slot 10a is <NUM>, there are <NUM> layers of flat wire conductors in each iron core slot 10a, the layer closest to the axis of the iron core <NUM> is a first layer, then there are a second layer, a third layer, a fourth layer, a fifth layer, a sixth layer, a seventh layer and an eighth layer outwards in a radial direction of the iron core <NUM> in sequence, which are distinguished by Roman characters " I ", "II". "VIII" in <FIG>, <FIG>, respectively.

Optionally, as shown in <FIG>, the coils <NUM> include a plurality of branches <NUM>. During wiring of the flat wire motor, the plurality of branches <NUM> of the coils <NUM> are connected in parallel, so that a larger current can flow into the coils <NUM>, and a more powerful magnetic field can be formed.

The same coil <NUM> may include Z branches <NUM>, and Z is an integer no smaller than <NUM>. In the example of the disclosure, description is made by taking the coil <NUM> including <NUM> branches <NUM> as an example. In other examples, the coil <NUM> may also include less or more branches <NUM>.

As shown in <FIG>, the plurality of branches <NUM> in the same coil <NUM> are arranged by offset of one iron core slot 10a in sequence in the circumferential direction of the iron core <NUM>. As shown in <FIG>, at the first end of the coil <NUM>, the plurality of branches <NUM> are connected in one-to-one correspondence with a plurality of branches <NUM> of one coil <NUM> of two coils <NUM> adjacent to the coil through a plurality of first jumper wires <NUM>. At the second end of the coil <NUM>, the plurality of branches <NUM> are connected in one-to-one correspondence with a plurality of branches <NUM> of the other coil <NUM> of the two coils <NUM> adjacent to the coil through a plurality of second jumper wires <NUM>.

Taking one coil <NUM> shown in <FIG> as an example, the <NUM> branches <NUM> are offset by one iron core slot 10a in sequence in a first direction. In this way, at the first end and the second end of the coil <NUM>, the <NUM> branches <NUM> are closer to one another, so that the first jumper wires <NUM> and the second jumper wires <NUM> are conveniently arranged for wiring.

For convenience of description, (n, m) is defined to represent the mth layer of the number n iron core slot 10a. One branch <NUM> of one coil <NUM> crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), then crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), then crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), then crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), then crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), then crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), and then crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>). The branch <NUM> crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>) to be connected to a branch <NUM> in the adjacent coil <NUM>. The branch crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), then crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), then crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), then crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), then crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), then crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>) and then crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>). The branch <NUM> crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>) to be connected to a branch <NUM> of another adjacent coil <NUM>, winding is repeated in the same mode till reaching (<NUM>, <NUM>), and thus one branch <NUM> of the plurality of coils <NUM> is connected in series in sequence. An outgoing line may be connected to (<NUM>, <NUM>) and (<NUM>, <NUM>) separately. The other branches may be connected in the same mode. A connection position of the outgoing line is merely an example, and in other examples, the outgoing line may be led out from other positions.

As shown in <FIG>, the branch <NUM> includes a first sub-coil <NUM> and a second sub-coil <NUM> connected to each other, and the first sub-coil <NUM> is located on a side of the second sub-coil <NUM> close to the axis of the iron core <NUM>.

The first sub-coil <NUM> is wound in the two iron core slots 10a which are mutually spaced, the second sub-coil <NUM> is wound in the other two iron core slots 10a which are mutually spaced, the two iron core slots 10a where the second sub-coil <NUM> is located are offset by one iron core slot 10a in the same direction respectively relative to the two iron core slots 10a where the first sub-coil <NUM> is located.

Taking one branch <NUM> of one coil <NUM> as an example, as shown in <FIG>, the first sub-coil <NUM> crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), then crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>) and then crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>). The first sub-coil <NUM> crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>) to be connected to one end of the second sub-coil <NUM>. The second sub-coil <NUM> crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), then crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>) and then crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>).

That is, the first sub-coil <NUM> and the second sub-coil <NUM> are not wound in the same two iron core slots 10a, rather, the first sub-coil <NUM> and the second sub-coil <NUM> are staggered by a certain distance in a circumferential direction of the iron core <NUM>.

In the example, the two iron core slots 10a in which the first sub-coil <NUM> is wound are spaced at an interval of <NUM> iron core slots 10a, the first sub-coil <NUM> is located outside the two iron core slots 10a, a span of a flat wire conductor connected with the two iron core slots 10a in a crossing mode is <NUM>, and the span refers to the quantity (of the iron core slots 10a between the two connected iron core slots 10a) plus <NUM>. For example, the flat wire conductor is connected with the two adjacent iron core slots 10a, so the span is <NUM>. The two iron core slots 10a in which the second sub-coil <NUM> is wound are also spaced at an interval of <NUM> iron core slots 10a, the second sub-coil <NUM> is located outside the two iron core slots 10a, and a span of a flat wire conductor connected with the two iron core slots 10a in a crossing mode is also <NUM>. In the coil <NUM>, connected ends of the first sub-coil <NUM> and the second sub-coil <NUM> are spaced at an interval of merely <NUM> iron core slots 10a, so the span is <NUM>. This is for making a pitch smaller than a pole distance to form a short-chord winding. The short-chord winding can weaken higher harmonics, vibration in a motor running process is reduced, noise is lowered, and an NVH (noise, vibration and harshness) performance is improved.

The first sub-coil <NUM> crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), and crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), the second sub-coil <NUM> crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>) and crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), spans of these parts are the same, which cross between two adjacent layers, so flat wire conductors of these parts may have the same structure, thus the process difficulty is further reduced, and the production efficiency is improved.

Optionally, the quantity of turns of the first sub-coil <NUM> is the same as the quantity of turns of the second sub-coil <NUM>, that is, relative offset of the first sub-coil <NUM> and the second sub-coil <NUM> occurs in a middle position of the coil <NUM>, which helps to guarantee balance of the winding.

As shown in <FIG>, in the plurality of first jumper wires <NUM> connecting the adjacent coils <NUM>, spans of the plurality of first jumper wires <NUM> are equal.

In the example, the coil <NUM> includes three branches <NUM>, so at the first end of the coil <NUM>, there are three first jumper wires <NUM> connecting the adjacent coils <NUM>. The first first jumper wire <NUM> crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), the second first jumper wire <NUM> crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), the third first jumper wire <NUM> crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>), and each of spans of the three first jumper wires <NUM> is <NUM>.

In this way, the three first jumper wires <NUM> may completely have the same structure, so that structure varieties of the flat wire conductors are further reduced, the process difficulty is lowered, and the production efficiency is improved.

Likewise, in some examples, in the plurality of second jumper wires <NUM> connecting the adjacent coils <NUM>, spans of the plurality of second jumper wires <NUM> are equal, so the plurality of second jumper wires <NUM> may completely have the same structure, thus the process difficulty is further reduced, and the production efficiency is improved.

In the example of the disclosure, in the plurality of second jumper wires <NUM> connecting the adjacent coils <NUM>, a span of at least one second jumper wire <NUM> is larger than spans of the other second jumper wires <NUM>.

By making the span of one second jumper wire <NUM> larger than the spans of the other second jumper wires <NUM>, it is conducive to guaranteeing balance of the winding.

In some examples, if the same coil <NUM> includes Z branches <NUM>, in the plurality of second jumper wires <NUM> connecting the adjacent coils <NUM>, the span of the second jumper wire <NUM> with the largest span is k+Z, each of the spans of the other second jumper wires <NUM> is k, and k is a positive integer.

As shown in <FIG>, at the second end of the coil <NUM>, there are three second jumper wires <NUM> connecting the adjacent coils <NUM>, the first second jumper wire <NUM> crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>) and has a span of <NUM>, the second second jumper wire <NUM> crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>) and has a span of <NUM>, and the third second jumper wire <NUM> crosses from (<NUM>, <NUM>) to (<NUM>, <NUM>) and has a span of <NUM>.

In other examples, as for the flat wire stator whose coil <NUM> includes four branches <NUM>, a span of the second jumper wire <NUM> with the largest span may be <NUM>, and each of spans of the other three second jumper wires <NUM> is <NUM>.

Apart from the second jumper wire <NUM> with the largest span, the spans of the other second jumper wires <NUM> are equal, which helps to reduce the structure varieties of the second jumper wires <NUM>, the process difficulty is further lowered, and the production efficiency is improved.

Each coil <NUM> is formed by connection of a plurality of hair-pin flat wires. As an example, the example of the disclosure provides structures of five types of hair-pin flat wires.

<FIG> is a schematic structural diagram of a first hair-pin flat wire provided by an example of the disclosure. Three first hair-pin flat wires <NUM> are shown in the figure. As shown in <FIG>, the first hair-pin flat wire <NUM> includes two first straight-line sections <NUM> and a first crossing-connection section <NUM> which is connected with the two first straight-line sections <NUM>. When being installed on the iron core <NUM>, the two first straight-line sections <NUM> are located in the two iron core slots 10a and in a first layer in the iron core slots 10a. For example, six first straight-line sections <NUM> of the three first hair-pin flat wires <NUM> in <FIG> may correspond to (<NUM>, <NUM>), (<NUM>, <NUM>), (<NUM>, <NUM>), (<NUM>, <NUM>), (<NUM>, <NUM>) and (<NUM>, <NUM>) in <FIG>, respectively. The first crossing-connection section <NUM> is the first jumper wire <NUM>. A span of the first crossing-connection section <NUM> is <NUM>.

<FIG> is a schematic structural diagram of a second hair-pin flat wire provided by an example of the disclosure. Three second hair-pin flat wires <NUM> are shown in the figure. As shown in <FIG>, the second hair-pin flat wire <NUM> includes two second straight-line sections <NUM> and a second crossing-connection section <NUM> which is connected with the two second straight-line sections <NUM>. When being installed on the iron core <NUM>, the two second straight-line sections <NUM> are located in the two iron core slots 10a and in a second layer and a third layer in the iron core slots 10a. For example, six second straight-line sections <NUM> of the three second hair-pin flat wires <NUM> in <FIG> may correspond to (<NUM>, <NUM>), (<NUM>, <NUM>), (<NUM>, <NUM>), (<NUM>, <NUM>), (<NUM>, <NUM>) and (<NUM>, <NUM>) in <FIG>, respectively. A span of the second crossing-connection section <NUM> is <NUM>.

<FIG> is a schematic structural diagram of a third hair-pin flat wire provided by an example of the disclosure. Three third hair-pin flat wires <NUM> are shown in the figure. As shown in <FIG>, the third hair-pin flat wire <NUM> includes two third straight-line sections <NUM> and a third crossing-connection section <NUM> which is connected with the two third straight-line sections <NUM>. When being installed on the iron core <NUM>, the two third straight-line sections <NUM> are located in the two iron core slots 10a and in a fourth layer and a fifth layer in the iron core slots 10a. For example, six third straight-line sections <NUM> of the three third hair-pin flat wires <NUM> in <FIG> may correspond to (<NUM>, <NUM>), (<NUM>, <NUM>), (<NUM>, <NUM>), (<NUM>, <NUM>), (<NUM>, <NUM>) and (<NUM>, <NUM>) in <FIG>, respectively. A span of the third crossing-connection section <NUM> is <NUM>.

<FIG> is a schematic structural diagram of a fourth hair-pin flat wire provided by an example of the disclosure. Three fourth hair-pin flat wires <NUM> are shown in the figure. As shown in <FIG>, the fourth hair-pin flat wire <NUM> includes two fourth straight-line sections <NUM> and a fourth crossing-connection section <NUM> which is connected with the two fourth straight-line sections <NUM>. When being installed on the iron core <NUM>, the two fourth straight-line sections <NUM> are located in the two iron core slots 10a and in a sixth layer and a seventh layer in the iron core slot 10a. For example, six fourth straight-line sections <NUM> of the three fourth hair-pin flat wires <NUM> in <FIG> may correspond to (<NUM>, <NUM>), (<NUM>, <NUM>), (<NUM>, <NUM>), (<NUM>, <NUM>), (<NUM>, <NUM>) and (<NUM>, <NUM>) in <FIG>, respectively. A span of the fourth crossing-connection section <NUM> is <NUM>.

<FIG> is a schematic structural diagram of a fifth hair-pin flat wire provided by an example of the disclosure. Three fifth hair-pin flat wires <NUM> are shown in the figure. As shown in <FIG>, the fifth hair-pin flat wire <NUM> includes two fifth straight-line sections <NUM> and a fifth crossing-connection section <NUM> which is connected with the two fifth straight-line sections <NUM>. When being installed on the iron core <NUM>, the two fifth straight-line sections <NUM> are located in the two iron core slots 10a and in an eighth layer in the iron core slots 10a. For example, six fifth straight-line sections <NUM> of the three fifth hair-pin flat wires <NUM> in <FIG> may correspond to (<NUM>, <NUM>), (<NUM>, <NUM>), (<NUM>, <NUM>), (<NUM>, <NUM>), (<NUM>, <NUM>) and (<NUM>, <NUM>) in <FIG>, respectively. The fifth crossing-connection section <NUM> is the second jumper wire <NUM>. Spans of the fifth crossing-connection sections <NUM> of the three fifth hair-pin flat wires <NUM> are <NUM>, <NUM> and <NUM> respectively.

After the first hair-pin flat wires <NUM>, the second hair-pin flat wires <NUM>, the third hair-pin flat wire <NUM>, the fourth hair-pin flat wires <NUM> and the fifth hair-pin flat wires <NUM> are installed on the iron core <NUM>, a part of hair-pin flat wires may be welded, so that the first phase winding <NUM> is formed through connection.

An example of the disclosure further provides a motor. The motor includes a rotor and the flat wire stator shown in <FIG>.

Claim 1:
A flat wire stator, comprising an iron core (<NUM>) and a flat wire winding (<NUM>), wherein
the iron core (<NUM>) has a plurality of iron core slots (10a);
the flat wire winding (<NUM>) comprises a first phase winding (<NUM>), the first phase winding (<NUM>) comprises a plurality of coils (<NUM>), the plurality of coils (<NUM>) are distributed in rotational symmetry around an axis of the iron core (<NUM>), the coils (<NUM>) are wound in some iron core slots (10a) of the plurality of iron core slots (10a), first ends and second ends of the coils (<NUM>) are located at the same end of the iron core (<NUM>), the first ends are located on sides of the iron core slots (10a) close to the axis in the radial direction of the iron core (<NUM>), and the second ends are located on sides of the iron core slots (10a) away from the axis in the radial direction of the iron core (<NUM>); and
the plurality of coils (<NUM>) are connected in series in sequence, the first end of a coil (<NUM>) is connected to the first end of one coil (<NUM>) of two coils (<NUM>) adjacent to the coil, and the second end of the coil (<NUM>) is connected to the second end of the other coil (<NUM>) of the two coils (<NUM>) adjacent to the coil;
characterized in that,
the coils (<NUM>) comprise a plurality of branches (<NUM>);
the plurality of branches (<NUM>) in the same coil (<NUM>) are arranged by offset of one iron core slot (10a) in sequence in a circumferential direction of the iron core (<NUM>);
at the first end of the coil (<NUM>), the plurality of branches (<NUM>) are connected in one-to-one correspondence with a plurality of branches (<NUM>) of one coil (<NUM>) of two coils (<NUM>) adjacent to the coil through a plurality of first jumper wires (<NUM>); and
at the second end of the coil (<NUM>), the plurality of branches (<NUM>) are connected in one-to-one correspondence with a plurality of branches (<NUM>) of the other coil (<NUM>) of the two coils (<NUM>) adjacent to the coil through a plurality of second jumper wires (<NUM>).