KR20210135846A - Stator and method of product the same - Google Patents

Abstract

According to an embodiment of the present invention, disclosed are a manufacturing method of a stator capable of simultaneously welding a plurality of wire connection parts and a stator manufactured by the same. The plurality of wire connection parts are fixed by a fastening member and the plurality of fixed wire connection parts are simultaneously coupled by friction stir welding.

Description

Stator and manufacturing method thereof

The present invention relates to a stator and a method for manufacturing the same, and more particularly, to a stator having a stator coil coupled to each other by a friction stir welding (FSW) method and a method for manufacturing the same.

A motor is a device that converts electrical energy into mechanical energy.

For energy conversion, the motor includes a stator core and a rotor on which a stator coil is wound.

The stator coil is wound in a predetermined pattern on the stator core, and is electrically connected to an external power source to receive electrical energy.

As current flows through the stator coil by an external power source, a magnetic field is formed around the stator coil.

The magnetic field formed in the stator coil interacts with the magnetic field formed in the rotor, and the interaction causes the rotor to rotate with respect to the stator core.

That is, the electrical energy supplied to the stator coil is converted into rotational energy of the rotor.

The stator coil may be implemented in various sizes according to the size of the output that the motor can generate.

Since a large amount of current flows in a motor having a relatively high output, when a stator coil having a conductor having an excessively small cross-sectional area is used, the amount of heat generated increases and the stator coil may be damaged. Accordingly, a stator coil having a conductor having a relatively large cross-sectional area may be used for a high-output motor.

However, in the case of a stator coil having a relatively large cross-sectional area, there is a problem in that coupling between the stator coils is not easy compared to a stator coil having a relatively small cross-sectional area.

Prior Art Document 1 (US Patent Publication No. 8,584,346 B2) discloses a stator having a stator coil having a rectangular cross-sectional shape. Specifically, a stator having a structure in which contact portions in which adjacent different stator coils are in contact with each other are energably coupled to each other by welding is disclosed.

However, in the stator disclosed in Prior Art Document 1, since a large number of contact portions are respectively coupled for welding, the more the contact portions increase, the more time and cost incurred in the coupling operation between the stator coils may increase.

In addition, prior art document 2 (Republic of Korea Patent Publication No. 10-1365469) discloses a stator having a stator coil having a rectangular cross-sectional shape. Specifically, a stator having a structure in which contact portions in which adjacent different stator coils are in contact with each other are energably coupled to each other by a connecting member is disclosed.

However, since the stator disclosed in Prior Art Document 2 requires a separate connection member, the manufacturing cost of the stator may increase. In addition, since the surfaces are pressed and contacted with each other, when the pressure applied to each other is reduced or a separation occurs between the surfaces in contact with each other, there may be a problem in that the electrical connection becomes unstable.

Prior Art Document 1: US Registered Patent Publication No. US 8,584,346 B2 (Registered on November 19, 2013) Prior Art Document 2: Republic of Korea Patent Publication No. 10-1365469 (Registered on Feb. 14, 2014)

An object of the present invention is to provide a stator having a structure capable of solving the above-described problems and a method for manufacturing the same.

First, an object of the present invention is to provide a stator having a structure that does not require an additional member for electrically connecting a connection portion, which is a portion to which different stator coils are connected, and a method of manufacturing the same.

In addition, an object of the present invention is to provide a stator having a structure capable of connecting a plurality of connecting portions to be energized at the same time, and a method for manufacturing the same.

Another object of the present invention is to provide a stator having a structure capable of rapidly connecting a plurality of connecting parts even when the number of connecting parts is increased, and a method for manufacturing the same.

In order to achieve the above object, a stator according to an embodiment of the present invention includes a stator core having a plurality of slots and a plurality of hairpins inserted into the slots.

In addition, the plurality of inserted hairpins protrude toward one side of the stator core, and a stripping powder from which the insulating coating is removed is formed at each end of the protruding portion.

In addition, the peeling portions are arranged to overlap along the radial direction of the stator core.

In addition, two peeling parts adjacent to each other in the radial direction among the peeling parts are joined to form a coil pair.

In addition, the coil pair is formed in plurality, and the joining of the two stripping parts constituting the coil pair is performed by friction stir welding.

In addition, the stator according to an embodiment of the present invention, a stator core having a plurality of slots; and a stator coil formed to connect a plurality of hairpins inserted into the slot in a preset pattern.

In addition, the hairpin includes a conductor and an insulating coating surrounding the conductor, and a plurality of the hairpins are inserted into each of the plurality of slots and are sequentially arranged along the radial direction of the stator core.

In addition, a skin-removing powder from which the insulating coating is removed by a predetermined length is formed on an end portion protruding toward one side of the stator core among the plurality of hairpins.

In addition, the stripping parts of the plurality of hairpins are sequentially arranged along the radial direction of the stator core.

In addition, among the stripping parts arranged sequentially, the stripping part arranged in the 2n-1th order and the stripping part arranged in the 2nth order are joined to each other to form a plurality of coil pairs, and n is a natural number.

In addition, the stripping parts constituting the coil pair are joined to each other by friction stir welding.

In addition, before the friction stir welding is performed, a fixing member is disposed on one side of the stator core, and a plurality of fixing holes are formed through the fixing member at positions corresponding to the plurality of pairs of coils.

In addition, the plurality of pairs of coils are inserted into the plurality of fixing holes, and circumferential surfaces of the plurality of pairs of coils are pressed by a fixing member to be fixed in the radial direction of the stator core.

In addition, the friction stir welding is performed by rotating or vibrating friction members in contact with both surfaces facing the circumferential direction of the stator core among the parts of the coil pair in a radial direction of the stator core among the plurality of coil pairs. The coil pairs overlapping with each other may be in contact with the friction member at the same time.

In addition, the friction stir welding is performed by rotating or vibrating a friction member in contact with one side of the coil pair facing the axial direction of the stator core, and the plurality of coil pairs are in contact with the friction member at the same time. can be

Further, the friction member vibrates in a radial direction of the stator core.

In addition, the method for manufacturing a stator according to an embodiment of the present invention includes the steps of: (a) inserting a plurality of hairpins into each of a plurality of slots formed through the stator core and sequentially arranging them in a radial direction of the stator core; (b) forming a stripped portion by removing the insulating coating of an end portion protruding toward one side of the stator core among the plurality of hairpin portions by a predetermined length; (c) sequentially arranging the plurality of hairpin parts in a radial direction of the stator core; (d) forming a plurality of pairs of coils by contacting the stripping part arranged in the 2n-1th order and the stripping part arranged in the 2n-th order among the stripping parts sequentially arranged; and (e) joining a plurality of the coil pairs by friction stir welding. Here, n is a natural number.

In addition, the step (c) may include: (c1) bending a portion of the plurality of hairpins protruding toward one side of the stator core by a predetermined angle in a clockwise or counterclockwise direction; and (c2) bending the plurality of hairpins in the axial direction so that the portions in which the skin parts are formed overlap along the radial direction of the stator core.

In addition, the step (d) comprises the steps of: (d1) fixing the skin parts in contact with each other using a fixing member so as not to move arbitrarily along the radial direction of the stator core; and (d2) grinding one side facing the axial direction of the stator core among a plurality of parts of the coil pair to remove a step difference between the peeling parts in contact with each other constituting the coil pair.

In addition, the step (e) may include (e1) contacting a friction member with one side of the coil pair facing the axial direction of the stator core; (e2) vibrating or rotating the friction member while in contact with the one surface facing the axial direction; and (e3) heating and bonding the skin removal parts in contact with each other constituting the coil pair.

In addition, the plurality of pairs of coils may be simultaneously joined by vibration or rotation of the friction member.

In addition, the step (e) may include (e1) contacting the friction member with both sides of the stator core facing the circumferential direction of the coil pair; (e2) vibrating or rotating the friction member while in contact with the both surfaces; and (e3) heating and bonding the skin removal parts in contact with each other constituting the coil pair.

In addition, the friction member is in contact with the coil pairs overlapping in the radial direction of the stator core of the plurality of coil pairs at the same time, and the coil pairs overlapping in the radial direction of the stator core by vibration or rotation of the friction member can be joined at the same time.

In addition, the step (e) may include: (e1) contacting the first friction member with one side of the coil pair facing the axial direction of the stator core; (e2) vibrating or rotating the first friction member while in contact with the one surface facing the axial direction; (e3) contacting a second friction member with both sides of the stator core facing the circumferential direction of the coil pair; (e4) vibrating or rotating the second friction member while in contact with the both surfaces; and (e5) heating and bonding the skin removal parts in contact with each other constituting the coil pair.

In addition, after the step (e), (f) it includes the step of removing the bead (bead) formed in the portion to which the skin removal powder is bonded. Here, the beads are removed by milling.

In addition, after the step (f), (g) the plurality of bonded coil pairs are subjected to stress relief heat treatment.

According to an embodiment of the present invention, the following effects can be achieved.

First, since the plurality of coil pairs arranged along the radial direction of the stator core are simultaneously welded by rotation or vibration of the friction member, the time and cost required for welding the coil pairs can be reduced.

In addition, even when the number of coil pairs is increased in the radial direction of the stator core, a plurality of coil pairs arranged in the radial direction may be simultaneously welded by rotation or vibration of the friction member. That is, in a high-power motor in which a relatively large number of coil pairs are formed, the time and cost required for welding the coil pairs can be reduced.

In addition, since the coil pair is welded by rotation or vibration of the friction member, a separate metal member or binding member for coupling the coil pair is not required.

In addition, the coil pair is coupled by frictional heat with the friction member. The contacted conductors constituting the coil pair are joined by melting and bonding the contacting edge portions at the same time. Since the conductors joined in contact with each other have the same coefficient of thermal expansion, the possibility of breakage of the weld by thermal expansion is significantly reduced.

In addition, since a separate welding electrode is not required for coupling the coil pair, it is possible to prevent the insulation coating adjacent to the coil pair from being damaged by the high-temperature welding electrode.

1 is a perspective view illustrating a stator core according to an embodiment of the present invention.
FIG. 2 is a front view of FIG. 1 ;
FIG. 3 is a plan view of FIG. 1 .
4 is a perspective view of the neutral wire of FIG. 1 .
5 is a perspective view of the hairpin of FIG. 1 ;
6 is a cross-sectional view of the hairpin of FIG. 5 .
7 is a schematic connection diagram of the stator coil of FIG. 1 .
8 is a graph illustrating a voltage sharing ratio of each coil unit of FIG. 7 .
9 is a cross-sectional view illustrating an arrangement state of the hairpin in the slot of FIG. 1 .
10 is a perspective view illustrating a coupling structure of a hairpin.
11 is an enlarged partial perspective view of the stator core of FIG. 1 .
12 is a flowchart illustrating a flow of a method for manufacturing a stator core according to an embodiment of the present invention.
13 is a flowchart illustrating a detailed flow of step S300 in FIG. 12 .
14 is a conceptual diagram illustrating a state in which hairpins are arranged according to step S300 of FIG. 12 .
15 is a flowchart illustrating a detailed flow of step S400 of FIG. 12 .
16 is a conceptual diagram illustrating a state in which a fixing member is inserted according to step S400 of FIG. 12 .
17 is a conceptual diagram illustrating a state in which the fixing member is inserted according to step S400 of FIG. 12 .
18 is a flowchart illustrating a detailed flow of an embodiment of step S500 of FIG. 12 .
19 is a conceptual diagram illustrating a welding process according to step S500 of FIG. 18 .
20 is a flowchart illustrating a detailed flow of another embodiment of step S500 of FIG. 12 .
21 is a conceptual diagram illustrating a welding process according to step S500 of FIG. 20 .
22 is a flowchart illustrating a detailed flow of another embodiment of step S500 of FIG. 12 .
23 is a conceptual diagram illustrating a state in which the skin stripping powder is welded according to step S500 of FIG. 18 .
24 is a conceptual diagram illustrating a state in which the skin stripping powder is welded according to step S500 of FIG. 20 .
25 is a conceptual diagram illustrating a state in which the skin stripping powder is welded according to step S500 of FIG. 22 .

Hereinafter, a stator and a manufacturing method thereof according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the following description, in order to clarify the characteristics of the present invention, descriptions of some components may be omitted.

1. Definition of terms

First, the terms used below are defined.

The term "starting" used below means that the stator 10 is switched from a stationary state to a dynamic state.

The term "operation" used below means that after the start of the stator 10 is finished, the stator 10 is maintained in a dynamic state.

The terms "upper" and "lower" used below may be understood with reference to the direction indication shown in FIG. 1 .

The term “circumferential direction” used below refers to a direction in which the stator core 100 rotates in a clockwise or counterclockwise direction with respect to the central axis.

The term "axial direction" used below means the direction of the central axis of the stator core 100 .

The term “radially inside” used below means a region having a shorter distance from the central axis of the stator core 100 than the one point based on one point.

The term “radially outside” used below means a region that is farther away from the central axis of the stator core 100 than the one point with respect to one point.

2. Description of the structure of the stator 10 according to an embodiment of the present invention

1 is a perspective view illustrating a stator core according to an embodiment of the present invention. FIG. 2 is a front view of FIG. 1 ; FIG. 3 is a plan view of FIG. 1 . 4 is a perspective view of the neutral wire of FIG. 1 .

1 to 4 , the stator 10 of the rotating electric machine according to the present embodiment includes a stator core 100 and a stator coil 200 wound around the stator core 100 .

The stator core 100 has a substantially annular cross-section and is formed to extend in one direction (the vertical direction in the embodiment shown in FIG. 1 ).

A rotor accommodating hole 100a in which a rotor (not shown) can be rotatably accommodated therein is formed through the stator core 100 .

In addition, the stator core 100 includes a plurality of slots 110 and teeth 120 . The plurality of slots 110 and the plurality of teeth 120 are alternately disposed along the circumferential direction of the stator core 100 .

In other words, the two slots 110 adjacent to each other in the circumferential direction of the stator core 100 are spaced apart from each other with the teeth 120 therebetween. An interval between two adjacent slots 110 may be defined as one pitch interval.

The stator core 100 may be formed by insulating and stacking a plurality of electrical steel plates 102 in one direction (up and down direction in the embodiment shown in FIG. 1 ).

The stator coil 200 includes a plurality of hairpins 300 penetrating the slot 110 .

The stator coil 200 is formed by winding a plurality of hairpins 300 inserted into the slot 110 in a preset pattern.

The plurality of hairpins 300 form a plurality of coil pairs C (refer to FIG. 10 ) at one side of the stator coil 200 to be electrically connected to each other.

The stator coil 200 includes a power input unit 210 for connecting each phase of an external power source to a coil unit 220 for each phase, which will be described later. In an embodiment, the external power source may be configured as an inverter for power supply.

The power input unit 210 includes a phase power input unit connected to each phase of an external power source. In one embodiment, the power input unit 210 is connected to the U-phase power input unit 210U connected to the U-phase of the external power, the V-phase power input unit 210V connected to the V-phase of the external power and the W-phase of the external power source. and a W-phase power input unit 210W.

The stator coil 200 includes a plurality of phase-specific coil units 220 connected to each phase power input unit.

A plurality of phase-by-phase coil unit 220 is, for example, a U-phase coil unit 220U connected to the U-phase power input unit 210U, a V-phase coil unit 220V connected to the V-phase power input unit 210V, and A W-phase coil unit 220W connected to the W-phase power input unit 210W is provided.

Each phase-specific coil unit 220 may include a plurality of n-th phase-specific coil units connected in parallel to each other.

In this embodiment, the U-phase coil unit 220U includes a first U-phase coil unit 220U1, a second U-phase coil unit 220U2, a third U-phase coil unit 220U3 and a 4U-phase coil unit connected in parallel to each other. (220U4) may be provided.

In addition, the V-phase coil unit 220V includes a first V-phase coil unit 220V1, a second V-phase coil unit 220V2, a third V-phase coil unit 220V3 and a fourth V-phase coil unit 220V4 that are connected in parallel to each other. can be provided.

In addition, the W-phase coil unit 220W includes a first W-phase coil unit 220W1, a second W-phase coil unit 220W2, a third W-phase coil unit 220W3 and a fourth W-phase coil unit 220W4 that are connected in parallel to each other. can be provided.

In the illustrated embodiment, each phase-specific coil unit 220 is formed by connecting four n-th phase-specific coil units in parallel with each other, but is not limited thereto, and may vary depending on the winding shape of the stator coil 200 .

One end of each of the plurality of phase-by-phase coil units 220 is energably connected to the power input unit 210, respectively, as described above. One end of the coil unit 220 for each phase connected to the power input unit 210 is disposed in the eighth layer (refer to FIG. 9 ) of the slot 110 .

In addition, the other end of each of the plurality of phase-by-phase coil units 220 is connected to the neutral wire 230 (see FIGS. 1 and 3 ).

As shown in FIG. 4, the neutral wire 230 protrudes from the arc-shaped body 231 and the body 231 and is connected to the other end of the coil unit 220 for each phase, respectively, for each phase connection terminal 233. to provide

Each phase connection terminal 233 is bent in a horizontal section 233b and a horizontal section 233b bent toward the center of the stator core 100 so that it can be connected to the other end of the coil unit 220 for each phase. It has a vertical section (233a) extending in the direction.

Each phase connection terminal 233 is connected to an end of each phase coil unit 220 disposed in the seventh layer (see FIG. 9 ) of the slot 110 .

3 , the hairpin 300 is not disposed on the eighth layer of the slot 110 in which the horizontal section 233b of the connection terminal 233 for each phase of the neutral wire 230 is disposed.

5 is a perspective view of the hairpin of FIG. 1 ; 6 is a cross-sectional view of the hairpin of FIG. 5 .

5 and 6 , the hairpin 300 is formed by bending a conductor having a predetermined length into an approximately “U” shape.

In addition, the hairpin 300 includes a conductive conductor 301 and an insulating coating 303 surrounding the surface of the conductor 301 .

In one embodiment, the conductor 301 may have a rectangular cross-section. The conductor 301 having a rectangular cross section may be stacked in layers in the slot 110 , so that the area ratio of the conductor to the area of the slot may be increased.

In an embodiment, the conductor 301 may be formed of a copper (Cu) material.

In one embodiment, the insulating coating 303 may be formed of a PI (polyimide) material.

In addition, the hairpin 300 is inserted into the slot 110 and includes a pair of insertion portions 320 extending in one direction. The one direction may be defined as an “insertion direction” of the insertion part 320 .

The insertion direction length of the insertion part 320 may be formed to be longer than the extension direction length of the stator core 100 . Through this, the insertion part 320 may penetrate the slot 110 of the stator core 100 .

The pair of insertion units 320 are spaced apart from each other by a predetermined distance and inserted into different slots 110 .

For example, the pair of insertion units 320 may be inserted with an interval of 12 slot pitch. One slot pitch is a term defining the spacing between the slots 110 adjacent to each other in the circumferential direction of the stator core 100 .

For example, the fourth slot and the third slot are spaced apart by one slot pitch. Specifically, when any one insertion part 320 is inserted into the first slot S1 , the other insertion part 320 is a thirteenth spaced apart by a pitch of 12 slots along the circumferential direction of the stator core 100 . It is inserted into the slot (S13).

In addition, the hairpin 300 includes a connection part 310 connecting one end of the pair of insertion parts 320 . In the illustrated embodiment, the one end means the lower end.

The connection part 310 is bent in an approximate "V" shape. However, the bent shape of the connection part 310 may be formed differently depending on the connection pattern of the stator coil 200 .

In addition, the hairpin 300 includes a pair of protrusions 330 respectively extending in one direction from the other end of the pair of insertion parts 320 . In the illustrated embodiment, the one direction means an upward direction, and the other end means an upper end.

Each of the pair of protrusions 330 includes an inclined portion 331 that is bent in the circumferential direction of the stator core to form a predetermined angle with the insertion portion 320 .

In the illustrated embodiment, all of the pair of inclined portions 331 are bent to one side in the circumferential direction, but the pair of inclined portions 331 are bent to one side in the circumferential direction and/or the other side opposite to the one side. can be

In other words, the inclined portion 331 of the hairpin 300 used for the connection may be bent clockwise and/or counterclockwise of the stator core, and the bent portion of the connection part 310 of the hairpin 300 used for the connection The shape may be provided in various ways.

That is, various types of hairpins 300 in which the inclined portion 331 and/or the connecting portion 310 are differently formed may be used.

In addition, each of the pair of protrusions includes a connection portion 333 extending in one direction from one end of the pair of inclined portions 331 . In the illustrated embodiment, the one end refers to an upper end of the inclined portion 331 , and the one direction refers to an upper direction or an axial direction.

Specifically, as illustrated in an enlarged view in FIG. 5 , one end 3310 of the inclined portion 331 connected to the connection portion 333 may be curved to have a predetermined curvature. The connection part 333 is formed to extend in the axial direction from the curved end 3310 of the inclined part 331 .

A stripping part 3330 from which the insulating coating 303 is removed to a predetermined length is formed at an end of the connection part 333 . The stripping part 3330 of one hairpin 300 is energably coupled to the stripping part 3330 of the other hairpin 300, and through this, the two different hairpins 300 are energably connected.

In an embodiment, the two different stripping parts 3330 may be electrically coupled to each other by friction stir welding. The friction stir welding uses frictional heat generated between the two contacted objects and the friction member to melt the two contacted objects and join them together. The friction stir welding process will be described in detail later.

The peeling portion 3330 is formed to extend to a predetermined length along the axial direction. Since the peeling portion 3330 has the insulation coating 303 removed to lower the insulation performance, the height of the peeling portion 3330 is preferably formed as small as possible.

In the method of welding by adding a molten third metal to the two objects to be joined, the high-temperature welding rod is adjacent to the site to be welded. There is a risk that the insulation coating 303 of the adjacent connection part 333 may be damaged.

However, when the different stripping parts 3330 are joined by friction stir welding, the length of the stripping part 3330 can be formed relatively short because a high-temperature welding rod is not required.

Referring back to FIG. 1 , some of the hairpins 300 may be directly connected to the power input unit 210 to be energized. In this case, the hairpin 300 directly connected to the power input unit 210 may include a protrusion 330 that is bent outward in the radial direction and then bent again in the axial direction to extend.

The hairpin 300 directly connected to the power input unit 210 to be energized may be connected to a plurality of other hairpins 300 to form the coil unit 220 for each phase.

7 is a schematic connection diagram of the stator coil of FIG. 1 .

Referring to FIG. 7 , the phase-by-phase coil units 220 may be connected by a so-called triangular connection or delta connection method in which three power supply triangles are formed having the same size and a phase difference of 120 degrees.

Specifically, the U-phase coil unit 220U, the V-phase coil unit 220V, and the W-phase coil unit 220W may be connected by a triangular connection method or a delta connection method.

The stator coil 200 may be configured to, for example, start by delta connection when starting, and to be operated by wye connection during operation.

8 is a graph illustrating a voltage sharing ratio of each coil unit of FIG. 7 .

Referring to FIG. 8 , the stator coil 200 includes a plurality of phase-specific coil units 220 , and the plurality of phase-specific coil units 220 each includes a plurality of partial coil units connected in series with each other.

Taking the U-phase coil unit 220U as an example, the partial coil unit of the U-phase coil unit 220U includes the first coil unit 222U1, the second coil unit 222U2, the third coil unit 222U3 and the second coil unit. It may be composed of 4 coil units 222U4.

Each of the first coil unit 222U1, the second coil unit 222U2, the third coil unit 222U3, and the fourth coil unit 222U4 may be configured with a preset number of hairpins 300, respectively. .

Although the U-phase coil unit 220U has been described as an example, the V-phase coil unit 220V may include an n-th coil unit (unsigned), and the W-phase coil unit 220W may include an n-th coil unit (unsigned). code) may be provided.

Again, taking the U-phase coil unit 220U as an example, when power is applied to the stator coil 200 , the first coil unit 222U1 , the second coil unit 222U2 , the third coil unit 222U3 and the fourth A divided voltage is applied to the coil unit 222U4 differently from each other.

More specifically, when the power of the stator coil 200 is applied, the result of detecting the change of the input voltage according to time with an oscilloscope is as follows.

The voltage sharing ratio of the first coil unit 222U1 connected to the power input unit 210 of the coil unit 220 for each phase is the highest at 60% or more, and the second coil unit connected to the first coil unit 222U1 ( 222U2) is output with a voltage sharing ratio of 50% or more to less than 60%.

In addition, the voltage sharing ratio of the third coil unit 222U3 connected to the second coil unit 222U2 and the fourth coil unit 222U4 connected to the third coil unit 222U3 is approximately 40% or more to less than 50%. It can be seen that the output

The stator coil 200 of the rotating electric machine according to an embodiment of the present invention is a first disposed in a preset first section (voltage sharing section) 110a at the end of the power input unit 210 for inputting external power. It is configured to include a hairpin (voltage sharing hairpin) 300a and a second hairpin 300b disposed in the second section 110b after the first section (voltage sharing section) 110a.

Here, the protrusions 330a1 and 330a2 of the first hairpin (voltage sharing hairpin 300a) partially overlap in the radial direction of the stator core 100, and between the partially overlapped protrusions 330a1 and 330a2, the partial discharge An insulating member for suppressing generation may be provided.

9 is a cross-sectional view illustrating an arrangement state of the hairpin in the slot of FIG. 1 .

Referring to FIG. 9 , a plurality of hairpins (insertion parts) are inserted in the slot 110 of the stator core 100 while being spaced apart from each other in the radial direction.

In other words, a plurality of hairpins (insertion parts) are arranged in layers in the slot 110 to constitute a plurality of layers.

Specifically, in the slot 110 , the position at which the hairpin (insertion part) disposed on the innermost radial direction of the stator core 100 is inserted may be defined as the first layer 111 of the slot 110 .

Also, in the slot 110 , a position at which a hairpin (insertion part) disposed on the radially outermost side of the stator core 100 is inserted may be defined as the eighth layer 118 of the slot 110 .

Then, the space between the first layer 111 and the eighth layer 118 may be defined as the second layer 112 to the seventh layer 117 along the radial direction.

In the present embodiment, the hairpin (insertion part) is arranged in the slot 110 in eight layers along the radial direction, but the number of layers may be changed according to the shape of the stator core 100 . For example, the hairpin (insertion part) may be disposed in the slot 110 in six layers along the radial direction.

As described above, the stator coil 200 according to the present embodiment includes a first hairpin (voltage sharing hairpin) 300a disposed in the first section (voltage sharing section) 110a, and the first section (voltage sharing section) It is configured to include a second hairpin (300b) disposed in the second section (110b) after the sharing section) (110a).

Since a plurality of slots 110 are formed along the circumferential direction of the stator core 100 , a plurality of first hairpins 300a and second hairpins 300b are provided.

In this embodiment, since the power input unit 210 is positioned radially outside the slot 110 , the eighth layer 118 and the seventh layer 117 positioned on the radially outermost side of the slot 110 are the first A section (voltage sharing section) 110a is formed.

The sixth layer 116 , the fifth layer 115 , the fourth layer 114 , the third layer 113 , the second layer 112 , and the first layer 111 form a second section 110b. do.

The first coil unit 222U1 may be configured by a plurality of first hairpins 300a disposed in the first section 110a. In this case, the voltage sharing ratio of the first hairpin 330a disposed in the first section 110a may be set to 60% or more.

Also, the first coil unit 222U1 and the second coil unit 222U2 may be configured by a plurality of first hairpins 300a disposed in the first section 110a. In this case, the voltage sharing ratio of the first hatch pin 330a disposed in the first section 110a may be set to 50% or more.

Accordingly, when the stator 10 is started, a relatively high voltage is shared to the first hairpin 300a disposed in the first section 110a, and a relatively high voltage is shared to the second hairpin 300b disposed in the second section 110b. A relatively low voltage is shared compared to the first hairpin 300a.

10 is a perspective view illustrating a coupling structure of a hairpin.

In FIG. 10 , a coupling structure between different first hairpins 300a disposed in the first section 110a is shown. In order to clearly show the coupling structure, only a part of the first hairpin 300a disposed in the first section 110a is shown, and the rest is omitted.

Referring to FIG. 10 , protrusions 330a1 and 330a2 protruding from the first section 110a and extending in a direction away from one side of the stator core 100 are shown. The one side of the stator core 100 may be defined as an upper side with respect to the direction shown in FIG. 1 .

In the eighth layer 118 that is the outermost of the slot 110 in the radial direction, the first protrusion 330a1 protrudes and extends in a direction away from one side of the stator core 100 .

In addition, in the seventh layer 117 located radially inside the eighth layer 118 and adjacent to the eighth layer 118 , the second protrusion 330a2 protrudes from one side of the stator core 100 . extended in the direction

A plurality of first protrusions 330a1 are provided along the circumferential direction of the stator core 100 . In addition, a plurality of second protrusions 330a2 are provided along the circumferential direction of the stator core 100 .

However, in the illustrated embodiment, in order to clearly show the coupling structure of the first protrusion 330a1 and the second protrusion 330a2, two are shown respectively, and the rest are omitted.

The first protrusion 330a1 is bent to one side in the circumferential direction of the stator core 100 and extends at a predetermined angle with one side of the stator core 100 . After that, the first protrusion 330a1 is again bent and extended in the axial direction.

Specifically, the first protrusion 330a1 includes a first inclined portion 331a1 extending to one side in the circumferential direction of the stator core 100 while forming a predetermined angle with one side of the stator core 100 .

In other words, the first inclined portion 331a1 forms a predetermined angle with one side of the stator core 100 and extends in the counterclockwise direction of the stator core 100 .

In addition, the first protrusion 330a1 includes a first connection portion 333a1 that is bent and extended in the axial direction from the end of the first inclined portion 331a1.

In addition, a first stripping portion 3330a1 from which the insulating coating 303a1 is removed to a predetermined length is formed at one end of the first connection portion 333a1.

The second protrusion 330a2 is bent to the other side in the circumferential direction of the stator core 100 and extends at a predetermined angle with one side of the stator core 100 . After that, the second protrusion 330a2 is again bent and extended in the axial direction.

Specifically, the second protrusion 330a2 includes a second inclined portion 331a1 extending to the other side in the circumferential direction of the stator core 100 while forming a predetermined angle with one side of the stator core 100 .

In other words, the second inclined portion 331a2 forms a predetermined angle with one side of the stator core 100 and extends in the clockwise direction of the stator core 100 .

In addition, the second protrusion 330a2 includes a second connection portion 333a2 that is bent and extended in the axial direction from the end of the second inclined portion 331a2.

In addition, a second stripping portion 3330a2 from which the insulating coating 303a2 is removed to a predetermined length is formed at one end of the second connection portion 333a2.

The first protrusion 330a1 may be electrically coupled to the second protrusion 330a2 protruding from different slots.

In the illustrated embodiment, the first protrusion 330a1 and the second protrusion 330a2 coupled to each other are spaced apart from each other by a pitch of 12 slots. When the slot 110 from which one of the first protrusions 330a1 protrudes is referred to as a first slot S1, the second protrusion 330a2 coupled to any one of the first protrusions 330a1 is a thirteenth slot. It protrudes from (S13).

The first inclined portion 331a1 of the first protruding portion 330a1 protruding from the first slot S1 extends to one side in the circumferential direction, and a first connection portion 333a1 extending from the first inclined portion 331a1. is located on one side of the seventh slot S7.

In addition, the second inclined portion 331a2 of the second protruding portion 330a2 protruding from the thirteenth slot S13 extends to the other side in the circumferential direction, and extends from the second inclined portion 331a2 of the seventh slot S7. The second connection part 333a2 to be used is located on one side of the seventh slot S7.

Here, the first connection part 333a1 and the second connection part 333a2 overlap each other in the radial direction of the stator core 100, and the first stripping part 3330a1 of the first connection part 333a1 and The second stripping portion 3330a2 of the second connection portion 333a2 is coupled to each other so as to be energized.

In other words, the first stripping portion (3330a1) and the second stripping portion (3330a2) to which the conductor is exposed are in surface contact with each other and are coupled to each other so as to be energized. In one embodiment, the first stripping portion (3330a1) and the second stripping portion (3330a2) may be coupled to each other energizingly by friction stir welding.

The first protrusion 330a1 and the second protrusion 330a2 connected to each other by the above-described process form the coil pair C. As shown in FIG.

A plurality of coil pairs C are provided along the circumferential direction of the stator core 100 . Here, the first inclined portion 331a1 of one coil pair C may partially overlap the second inclined portion 331a2 of the other coil pair C in the radial direction of the stator core 100 . have.

In the illustrated drawings, the first hairpin 300a has been described as an example, but the second hairpin 300b disposed in the second section 110b may also be coupled in a similar manner to the coupling method of the first hairpin 300a. .

Specifically, the second hairpin 300b includes the first protrusion 330b1 protruding from the sixth layer 116 , the fourth layer 114 , and the second layer 112 , the fifth layer 115 , and the third layer. 113 and a second protrusion 330b2 protruding from the first layer 111 .

That is, the first protrusion 330b1 and the second protrusion 330b2 are alternately disposed in the sixth layer 116 to the first layer 111 .

Also, the first protrusion 330b1 includes a first inclined portion 331b1 and a first connection portion 333b1, and the second protrusion 330b2 includes a second inclined portion 331b2 and a second connection portion 333b2. includes

Any one of the first protrusions 330b1 and any one of the second protrusions 330b2 positioned radially inside the first protrusion 330b1 are coupled to each other to form a coil pair C.

For example, any one of the first protrusions 330b1 protruding from the sixth layer 116 and any one of the second protrusions 330b2 protruding from the fifth layer 115 are coupled to each other to form a coil pair (C) to form

The coupling structure of the coil pair C of the second hairpin 300b may be understood with reference to the description of the coupling structure of the coil pair C of the first hairpin 300a, and this will be replaced.

11 is a perspective view showing the coupling structure of the entire hairpin.

Referring to FIG. 11 , a plurality of coil pairs C are provided in a plurality along the radial direction of the stator core 100 .

The plurality of coil pairs C includes a first coil pair C1, a second coil pair C2, a third coil pair C3, and a fourth coil pair C4, and a first coil pair C1 ), the second coil pair C2 , the third coil pair C3 , and the fourth coil pair C4 are sequentially arranged from the radially outermost to the innermost of the stator core 100 .

Specifically, the first and second protrusions 330a1 and 330a2 respectively protruding from the eighth layer 118 and the seventh layer 117 are coupled to each other to form a first coil pair C1.

In addition, the first protrusion 330b1 and the second protrusion 330b2 respectively protruding from the sixth layer 116 and the fifth layer 115 are coupled to each other to form a second coil pair C2.

In addition, the first protrusion 330b1 and the second protrusion 330b2 respectively protruding from the fourth layer 114 and the third layer 113 are coupled to each other to form a third coil pair C3.

In addition, the first protrusion 330b1 and the second protrusion 330b2 respectively protruding from the second layer 112 and the first layer 111 are coupled to each other to form a fourth coil pair C4.

The first coil pair (C1) is provided with a first conducting portion (CCP1) formed by coupling each stripping portion (3330a1, 3330a2), the second coil pair (C2) to the third coil pair (C3) is each stripping The parts 3330b1 and 3330b2 are provided with a second conductive part CCP2 to a fourth conductive part CCP4 formed by being coupled to each other.

The first conductive part CCP1 , the second conductive part CCP2 , the third conductive part CCP3 , and the fourth conductive part CCP4 are disposed to overlap each other in the radial direction of the stator core 100 .

In the illustrated embodiment, four coil pairs C are provided along the radial direction of the stator core 100 , but this may be changed according to the size and connection structure of the stator core 100 .

Like the stator 10 according to the present invention, a relatively large number of welding parts may be generated in a stator used for a motor generating a relatively high output.

In the illustrated embodiment, 96 slots 110 are formed along the circumferential direction of the stator core 100 , and in each slot 110 , the first hairpin 300a and the second hairpin 300b are eight layers. It forms a layer and is inserted.

Accordingly, since four coil pairs are formed for each slot 110, a total of 384 coil pairs are formed. Since each coil pair is formed by welding, a total of 384 welds are generated.

When using the welding method by melting the two metals to be joined and the metal of a different material, the welding operation is performed one by one for each welding part.

In addition, even in the case where the coil pair C is energably coupled using a binding member (not shown) other than welding, the binding operation is performed by inserting the binding member into each energizing part CCP one by one.

In this case, not only the material cost required for the connection operation increases, but also the time and cost required for the connection operation increase because 384 welding parts must be individually welded.

In consideration of this problem, when friction stir welding that can weld a plurality of welding parts simultaneously without requiring additional materials for connection work is used, the time and cost required for the connection work can be reduced. can do it

Hereinafter, a method of manufacturing the stator 10 in which a connection operation is performed by friction stir welding will be described with reference to FIGS. 12 to 25 .

3. Description of the manufacturing method of the stator 10 according to an embodiment of the present invention

The stator 10 is manufactured by winding the stator coil 200 on the stator core 100 .

The stator coil 200 is formed by connecting a plurality of hairpins 300 in a preset pattern.

Specifically, a plurality of hairpins 300 are inserted into the slots 110 of the stator core 100 in a preset pattern.

The plurality of hairpins 300 are all inserted in the same direction along the axial direction.

Accordingly, on the upper side of the stator core 100 , a plurality of protrusions 330 are arranged to protrude from the upper surface of the stator core 100 by a predetermined length, and a plurality of bent portions in an approximate V-shape on the lower side of the stator core 100 . Connecting units 310 are arranged. "Upper side" and "lower side" of the stator core 100 may be understood with reference to FIG. 1 .

(1) Inserting a plurality of hairpins 300 into each of the plurality of slots 110 formed through the stator core 100 and sequentially arranging them in the radial direction of the stator core 100 (S100)

As described above, the plurality of hairpins 300 are inserted into the plurality of slots 110 , and the plurality of hairpins 300 are sequentially arranged along the radial direction of the stator core 100 .

Specifically, a plurality of insertion portions 320 of the plurality of hairpins 300 are arranged overlapping each other in the slot 110 in the radial direction of the stator core 100 . Referring to FIG. 9 , in the illustrated embodiment, the plurality of hairpins 300a and 300b are arranged in eight layers inside the slot 110 .

In addition, each of the hairpins 300a and 300b protrudes from the upper surface of the stator core 100 through the slot 110 . That is, the protrusions 330a and 330b, which are protruding portions of the respective hairpins 300a and 300b, protrude from the upper surface of the stator core 100 .

The plurality of protrusions 330a and 330b are arranged to overlap in the radial direction of the stator core 100 .

(2) of the plurality of hairpins 300, removing the insulating coating 303 of the end portion protruding to one side of the stator core 100 by a predetermined length to form the stripping portion 3330 (S200)

Since the hairpin 300 is composed of the conductor 301 and the insulating coating 303 surrounding the conductor 301, the insulating coating 303 must be removed from the portion where the hairpins 300 are joined to each other.

Accordingly, the insulating coating 303 of each end portion of the protrusions 330a and 330b protruding toward one side of the stator core 100 is removed by a predetermined length.

A stripping portion 3330 in which the conductor 301 is exposed is formed in the portion from which the insulating coating 303 is removed.

(3) Description of the step (S300) in which the stripping portions 3330 of the plurality of hairpins 300 are sequentially arranged along the radial direction of the stator core 100

The plurality of hairpins 300 are electrically connected to each other by bonding the peeling parts 3330 of the hairpins 300 to each other.

At this time, in order to form the stator coil 200 in a preset pattern, the stripping part 3330 is disposed in a slot 110 other than the slot 110 in which the peeling part protrudes.

To this end, a portion 330 protruding from one side of the stator core 100 among the plurality of hairpins 300 is bent by a predetermined angle in a clockwise or counterclockwise direction (S310).

For example, the protrusion 330a1 protruding from the eighth layer 118 (refer to FIG. 9) of the first slot S1 among the plurality of slots 110 forms a predetermined angle in the counterclockwise direction of the stator core 100, is bent The bent protrusion 330a1 is bent upward along the axial direction on the seventh slot S7 spaced apart from the first slot S1 by 6 slot pitches in the counterclockwise direction of the stator core 100 . That is, the peeling portion 3330a1 of the protrusion 330a1 protruding from the eighth layer 118 of the first slot S1 is disposed on the seventh slot.

In addition, the protrusion 330a2 protruding from the seventh layer 117 (refer to FIG. 9 ) of the thirteenth slot S13 spaced apart by 12 slot pitches counterclockwise from the first slot S1 among the plurality of slots 110 ) is bent at a predetermined angle in the clockwise direction of the stator core 100 . The bent protrusion 330a2 is bent upward along the axial direction on the seventh slot S7 spaced apart from the thirteenth slot S13 by 6 slot pitches in the clockwise direction. That is, the peeling portion 3330a1 of the protrusion 330a2 protruding from the seventh layer 117 of the thirteenth slot S13 is disposed on the seventh slot S7 .

That is, the portion in which the connection portion 333 of the plurality of hairpins 300 is formed is bent in the axial direction so that it overlaps along the radial direction of the stator core 100 ( S320 ).

Through this, the peeling portion 3330a1 of the protruding portion 330a1 protruding from the eighth layer 118 of the first slot S1 and the protruding portion 330a2 protruding from the seventh layer 117 of the thirteenth slot S13. The stripping portion 3330a2 of the is disposed to overlap along the radial direction of the stator core 100 on the upper side of the seventh slot (S7).

In the same manner, the peeling part 3330b1 of the protrusion 330b1 protruding from the sixth layer 116 of the first slot S1 and the protruding part protruding from the fifth layer 115 of the thirteenth slot S13. The stripping portion (3330b2) of the (330b2) is arranged to overlap along the radial direction of the stator core (100).

In the same manner, the peeling portion 3330b1 of the protruding portion 330b1 protruding from the fourth layer 114 of the first slot S1 and the protruding portion protruding from the third layer 113 of the thirteenth slot S13. The stripping portion (3330b2) of the (330b2) is arranged to overlap along the radial direction of the stator core (100).

In the same manner, the peeling portion 3330b1 of the protrusion 330b1 protruding from the second layer 112 of the first slot S1, and the protrusion protruding from the first layer 111 of the thirteenth slot S13. The stripping portion (3330b2) of the (330b2) is arranged to overlap along the radial direction of the stator core (100).

Referring to FIG. 14 , according to the above-described method, a plurality of peeling portions 3330 are arranged to overlap along the radial direction of the stator core 100 .

In the illustrated embodiment, the plurality of stripping portions 3330a1 , 3330a2 , 3330b1 , 3330b2 protruding from the first slot S1 and the thirteenth slot S13 are arranged to overlap in the radial direction of the stator core 100 . However, the present invention is not limited thereto and may vary depending on the size and winding shape of the stator 10 .

In an embodiment not shown, a plurality of stripping portions 3330a1, 3330a2, 3330b1, 3330b2 protruding from the first slot S1 and the eighth slot spaced apart by 7 pitches from the first slot S1 are the radius of the stator core. They may be arranged to overlap along the direction.

For clarity, only the protrusion 330 of the hairpin 300 protruding from the first slot S1 and the thirteenth slot S13 is illustrated, and the rest of the hairpin 300 is omitted.

(4) of the sequentially arranged stripping parts 3330, the step (S400) of forming a plurality of coil pairs (C) by contacting the stripping part arranged in the 2n-1st order and the stripping part arranged in the 2nth order with each other Explanation

When a plurality of peeling parts 3330 are overlapped and disposed along the radial direction of the stator core 100, of the sequentially arranged peeling parts 3330, the 2n-1th stripping part and the 2nth stripping part are arranged. The parts are brought into contact with each other to form a plurality of coil pairs (C). The term "coil pair C" used in the description of this step means the protrusions 330 that are in energized contact with each other before being welded. Wherein n means a natural number.

For example, when eight hairpins 300 are inserted into one slot 110, the first and second molting parts, the 3rd and 4th molting parts, the 5th and 6th The arranged stripping part and the 7th and 8th stripping parts are in contact with each other to form a coil pair (C).

In order to bring the peeling parts 3330 adjacent to each other in the radial direction of the stator core 100 into contact with each other, the fixing member 400 is fitted to the peeling parts 3330 arranged in the radial direction.

That is, the connection parts 333 in contact with each other are fixed using the fixing member 400 so that they do not move arbitrarily along the radial direction of the stator core 100 ( S410 ).

Referring to FIG. 16 , the fixing member 400 is implemented as a member through which a plurality of fixing holes 410 are formed along the axial direction of the stator core 100 .

Since the insertion part 320 of the eight hairpins 300 is inserted into one slot 110 , four coil pairs C are formed on the upper side of one slot 110 . Accordingly, the plurality of fixing holes 410 may be formed in four along the radial direction of the stator core 100 .

However, the present invention is not limited thereto, and when the insertion parts 320 of the six hairpins 300 are inserted into one slot 110 , the fixing holes 410 are formed into three pieces along the radial direction of the stator core 100 . can be formed.

That is, the number of fixing holes 410 may vary according to a pattern in which the stator coil 200 is wound.

In the illustrated embodiment, the fixing member 400 is configured to fix the peeling portion 3330 arranged along the radial direction on the upper side of one slot 110 . That is, it is configured to fix the peeling portion 3330 arranged along the radial direction on the upper side of the seventh slot.

However, the present invention is not limited thereto and may be configured to simultaneously fix the peeling portions 3330 arranged along the radial direction of the stator core 100 on the upper side of the plurality of slots 110 .

In an embodiment not shown, the fixing member 400 may be configured to fix the peeling portion 3330 arranged in the radial direction on the upper side of the seventh slot and the eighth slot. In this case, eight fixing holes 410 may be formed.

In an embodiment not shown, the fixing member 400 may be configured to fix the peeling portion 3330 arranged along the radial direction on the upper side of the entire slot. In this case, the fixed hole 410 may be formed in an annular shape corresponding to the stator core 100 , and the fixed hole 410 may be formed by multiplying the number of slots by half the number of layers. For example, when the stator 10 is formed of 96 slots and 8 layers, the number of fixing holes 410 formed in the annular fixing member 400 may be 384 (96 * 8 / 2).

The fixing hole 410 may be formed in a shape capable of fixing the two peeling parts 3330 adjacent in the radial direction of the stator core 100 so as not to move arbitrarily in the radial direction.

For example, when a rectangular flat copper wire is used for the hairpin 300 , the two flat copper wires in contact with each other have a rectangular cross section having predetermined horizontal and vertical lengths in a contact state. The horizontal and vertical lengths of the two flat copper wires in contact with each other may be formed to be substantially the same as the horizontal and vertical lengths of the fixing hole 410 .

For clarity, only the protrusion 330 of the hairpin 300 protruding from the first slot S1 and the thirteenth slot S13 is illustrated, and the rest of the hairpin 300 is omitted.

Referring to FIG. 17 , four coil pairs C are formed along the radial direction of the stator core 100 .

In the illustrated embodiment, in the radial direction of the stator core 100, the length L1 of the fixing hole 410 may be formed to be substantially equal to the length L2 of the two peeling parts 3330 in contact with each other. . Accordingly, the two peeling parts 3330 in contact with each other may be press-fitted into the fixing hole 410 to be fixed.

That is, the circumferential surface of the two stripping parts 3330 in contact with each other among the plurality of parts of the coil pair C is pressed by the fixing member and fixed in the radial direction of the stator core.

In the illustrated embodiment, the peeling parts (3330a1, 3330a2) in contact with each other on the upper side of the seventh and eighth layers and the peeling parts (3330b1. 3330b2) in contact with each other on the upper side of the first to sixth layers are fixed holes (410) inserted and fixed in

In a state in which the peeling parts 3330 in contact with each other are inserted into the fixing hole 410 , an error may be formed in the distance between the upper end surfaces of the two peeling parts 3330 and the upper side surfaces of the stator core 100 . For example, the shortest distance between the stripping part 3330b2 and the stator core 100 disposed on the upper side of the third layer and the shortest distance between the stripping part 3330b1 disposed on the upper side of the fourth layer and the stator core 100 . An error may occur in the distance. That is, a step may be formed between the two peeling parts 3330 in contact with each other.

Since the welding efficiency may be reduced during friction stir welding due to the step difference, one side facing the axial direction of the stator core 100 among parts of the plurality of coil pairs C is ground by grinding, the coil pair It is possible to remove the step difference between the connection parts in contact with each other forming (S420).

(5) Description of the step (S500) in which a plurality of coil pairs (C) are coupled by friction stir welding

A plurality of coil pairs (C) may be simultaneously coupled by friction stir welding in a state fixed by the fixing member (400).

For friction stir welding, the friction member 500 is in contact with the stripping upper surface 3331 and/or the stripping side 3332 of the stripping portion 3330 of the plurality of coil pairs (C) to rotate or vibrate. The peeling upper surface 3331 points to the upper side of the portion of the peeling portion 3330, and the peeling side surface 3332 refers to the surface facing the circumferential direction of the partial stator core 100 of the peeling portion 3330.

In the illustrated embodiment, the vibration direction of the friction member 500 may be the radial direction of the stator core 100 . That is, the vibration direction of the friction member 500 may be a direction in which the plurality of peeling parts 3330 are arranged.

When the friction member 500 rotates or vibrates while in contact with the peeling part 3330, the peeling part 3330 is heated and melted by the frictional heat generated between the friction member 500 and the peeling part 3330. The peeling parts 3330 that were in contact with each other in the process of re-solidifying the molten part are coupled to each other so as to be energized.

In one embodiment, the friction member 500 may be implemented with a metal material having a stronger strength than the metal material used for the peeling portion 3330 .

Since the friction member 500 is rotated or vibrated while in contact with the plurality of stripping parts 3330 arranged along the radial direction of the stator core 100 , the plurality of stripping parts 3330 may be simultaneously welded.

According to an embodiment, the friction member 500 may be in contact with the peeling upper surface 3331 of the peeling portion 3330 to perform friction stir welding.

According to the present embodiment, the first friction member 510 is brought into contact with one side facing the axial direction of the stator core 100 among the parts of the coil pair C (S510a).

Referring to FIG. 19 , the first and second peeling upper surfaces 3331a1 and 3331a2 of the first and second peeling parts 3330a1 and 3330a2 contacting each other on the upper surfaces of the seventh layer 117 and the eighth layer 118 . ) is in contact with the lower surface of the first friction member 510 . Similarly, the first and second peeling upper surfaces 3331b1 and 3331b2 of the first and second peeling parts 3330b1 and 3330b2 contacting each other on the upper surface of the first layer 111 to the sixth layer 116 are first It is in contact with the lower surface of the friction member 510 .

The first friction member 510 vibrates or rotates while in contact with one side facing the axial direction (S520a).

Specifically, in a state in which the first peeling upper surfaces 3331a1 and 3331b1 and the second peeling upper surfaces 3331b2 and 3331a2 are in contact with the lower surface of the first friction member 510, the first friction member 510 vibrates or rotates. do.

By the vibration or rotation of the first friction member 510, the first peeling upper surfaces 3331a1 and 3331b1 and the second peeling upper surfaces 3331a2 and 3331b2 are heated and melted. As the molten portion is solidified, the first peeling upper surfaces 3331a1 and 3331b1 and the second peeling upper surfaces 3331a2 and 3331b2 are integrally coupled to each other.

That is, the connection parts 333 in contact with each other constituting the coil pair C are heated and joined ( S530a ).

Referring to FIG. 23 , the first peeling portion 3330a1 and the second peeling portion 3330a2 in contact with each other are coupled by friction stir welding. Specifically, the first of the first peeling upper surface 3331a1 and the second peeling upper surface 3331a2 are in contact with each other, and the first peeling side surface 3332a1 and the second peeling side surface 3332a2 are in contact with each other. And the portion adjacent to the second peeling upper surface (3331a1, 3331a2) is melted and then solidified and integrally combined.

The first and second peeling parts 3330b1 and 3330b2 protruding from the first layer 111 to the sixth layer 116 and contacting each other are also coupled to each other in the same manner.

A bead 610 is formed around the integrally coupled portion.

According to another embodiment, the friction member 500 may be in contact with the peeling side 3332 of the peeling part 3330 to perform friction stir welding.

According to the present embodiment, the second friction member 520 is brought into contact with both surfaces of the stator core 100 facing the circumferential direction among the parts of the coil pair C (S510b).

Referring to FIG. 21 , the first and second peeling side surfaces 3332a1 and 3332a2 of the first and second peeling parts 3330a1 and 3330a2 that are in contact with each other on the upper side of the seventh layer 117 and the eighth layer 118 . ) is in contact with the second friction member 510 .

The first and second stripping side surfaces (3332a1, 3332a2) are both sides of the first and second stripping parts (3330a1, 3330a2) of the stator core 100 in the clockwise or counterclockwise direction. The second friction member 520 may be in contact with one side surface oriented in a clockwise or counterclockwise direction, and a plurality of second friction members 520 may be provided in contact with both sides oriented in the clockwise and counterclockwise directions.

Similarly, the first and second peeling sides 3332b1 and 3332b2 of the first and second peeling parts 3330b1 and 3330b2 that are in contact with each other on the upper surface of the first layer 111 to the sixth layer 116 are the second It is in contact with the friction member 520 .

In a state in contact with both surfaces, the friction member vibrates or rotates (S520b).

Specifically, in a state in which the first peeling side surfaces 3332a1 and 3332b1 and the second peeling side surfaces 3332a2 and 3332b2 are in contact with the second friction member 520 , the second friction member 520 vibrates or rotates.

By vibration or rotation of the second friction member 520, the first peeling side surfaces 3332a1 and 3332b1 and the second peeling side surfaces 3332a2 and 3332b2 are heated and melted. As the molten portion is solidified, the first peeling side (3332a1, 3332b1) and the second peeling side (3332a2, 3332b2) of the portion that was in contact with each other is integrally coupled.

That is, the connection parts 333 that are in contact with each other constituting the coil pair C are heated and joined ( S530b ).

Referring to FIG. 24 , the first and second peeling parts 3330a1 and 3330a2 in contact with each other are coupled by friction stir welding. Specifically, the first and second peeling side surfaces (3332a1, 3332a2) of the boundary portion in contact with each other, and the first and second peeling upper surfaces (3331a1, 3331a2) of the boundary portion in contact with each other ( 3332a1 and 3332a2) are melted and then solidified and integrally combined.

The first and second peeling portions 3330b1 and 3330b2 protruding from the first layer 111 to the sixth layer 116 and contacting each other are also coupled to each other in the same manner.

A bead (bead) 620 is formed around the integrally coupled portion.

According to another embodiment, the first friction member 510 and the second friction member 520 are in contact with the peeling upper surface 3331 and the peeling side surface 3332 of the peeling part 3330, so that friction stir welding can be performed. .

According to the present embodiment, the first friction member 510 is brought into contact with one side facing the axial direction of the stator core 100 among the parts of the coil pair C (S510c). Since this step is the same as the above-described step S510a, the description of this step is replaced with this.

In addition, in a state in which the first friction member 510 vibrates or rotates while in contact with one side facing the axial direction (S520c). Since this step is the same as the above-described step S520a, the description of this step is replaced with this.

In addition, the second friction member 520 is brought into contact with both sides of the stator core 100 facing the circumferential direction among the parts of the coil pair C ( S530c ). Since this step is the same as the above-described step S510b, the description of this step is replaced with this.

In addition, in a state in contact with both surfaces, the second friction member 520 vibrates or rotates (S540c). Since this step is the same as the above-described step S520b, the description of this step is replaced with this.

By the rotation or vibration of the first friction member 510 and the second friction member 520, the first peeling parts 3330a1 and 3330b1 and the second peeling parts 3330a2 and 3330b2 in contact with each other are melted and then integrally formed. solidified and bonded to each other.

That is, the connection parts 333 in contact with each other constituting the coil pair C are heated and joined ( S550c ).

Referring to FIG. 25 , the first and second peeling parts 3330a1 and 3330a2 in contact with each other are coupled by friction stir welding. Specifically, the first and second stripping side surfaces (3332a1, 3332a2) are in contact with each other, and the first and second stripping upper surfaces (3331a1, 3331a2) are in contact with each other, the boundary portion is melted and then solidified and integrally combined do.

The first and second peeling portions 3330b1 and 3330b2 protruding from the first layer 111 to the sixth layer 116 and contacting each other are also coupled to each other in the same manner.

A bead 630 is formed around the integrally coupled portion.

(6) Description of the step (S600) of removing the bead (bead) (610, 620, 630) formed in the portion where the peeling portion 3330 is bonded to each other

The first stripping portion (3330a1, 3330b1) and the second stripping portion (3330a2, 3330b2) is a step of removing the beads generated by friction stir welding (S600).

Referring back to FIGS. 23 to 25 , beads 610 , 620 , 630 are formed at the boundary between the first and second peeling parts 3330a1 and 3330a2 fused and joined by friction stir welding. By the bead, the boundary portion between the first and second peeling portions 3330a1 and 3330a2 protrudes compared to the other portions.

Accordingly, in this step, an operation for removing the bead is performed. In an embodiment, the bead may be removed by milling.

In an embodiment not shown, the boundary between the first and second peeling parts 3330b1 and 3330b2 protruding from the first layer 111 to the sixth layer 118 and fused and joined by friction stir welding is a bead ( 610, 620, 630 are formed. In an embodiment, the beads 610 , 620 , and 630 may be removed by milling processing.

(7) Description of the step (S700) in which a plurality of bonded coil pairs (C) are subjected to stress relief heat treatment

It is a step (S700) of heat-treating the first stripping parts (3330a1, 3330b1) and the second stripping parts (3330a2, 3330b2) combined by friction stir welding to remove stress that may be generated according to the coupling (S700).

Thermal stress due to high-temperature heat may remain in the first stripping parts 3330a1 and 3330b1 and the second stripping parts 3330a2 and 3330b2 melted and joined by the friction stir welding method.

Therefore, in this step, a treatment for removing the thermal stress remaining in each bonding site is performed.

The stress relief heat treatment may be performed in any form for removing thermal stress remaining in the inside of a metal material or the like. In an embodiment, the stress relief heat treatment may be performed in the form of annealing.

4. Explanation of Effects by Friction Stir Welding

Since the plurality of coil pairs C arranged along the radial direction of the stator core 100 are simultaneously welded by rotation or vibration of the friction members 510 and 520 , the time and cost required for welding the coil pairs C This can be reduced.

In addition, even when the number of coil pairs C is increased in the radial direction of the stator core 100 , a plurality of coil pairs C arranged in the radial direction are generated by rotation or vibration of the friction members 510 and 520 . can be welded simultaneously. That is, in a high-power motor in which a relatively large number of coil pairs C are formed, the time and cost required for welding the coil pairs C may be reduced.

In addition, since the coil pair C is welded by rotation or vibration of the friction members 510 and 520 , a separate metal member or binding member for coupling the coil pair C is not required.

In addition, the coil pair C is coupled by frictional heat with the friction members 510 and 520 . The contacted conductors 3330a1 , 3330a2 , 3330b1 , and 3330b2 constituting the coil pair C are coupled by melting and joining the contacting edge portions at the same time. Since the conductors 3330a1 , 3330a2 , 3330b1 , and 3330b2 contacted and coupled to each other have the same coefficient of thermal expansion, the possibility that the welded conductive portion CCP is damaged by thermal expansion is significantly reduced.

In addition, since a separate welding rod is not required for coupling the coil pair C, the insulation coating 303 adjacent to the current conducting portion CCP is prevented from being damaged by the high-temperature welding rod.

Although the above has been described with reference to the preferred embodiment of the present invention, those of ordinary skill in the art can variously modify and change the present invention within the scope without departing from the spirit and scope of the present invention described in the claims below. You will understand that you can.

10: stator
100: stator core
100a: rotor receiving hole
102: electrical steel sheet
110: slot
110a: first section (voltage sharing section)
110b: second section
111: first layer
112: second layer
113: third layer
114: fourth layer
115: fifth layer
116: sixth layer
117: seventh layer
118: eighth layer
120: Teeth
200: stator coil
210: power input
210W: W-phase power input
210U: U-phase power input
210V: V-phase power input
220: phase-by-phase coil part
220W: W phase coil part
220W1: 1W phase coil part
220W2: 2W phase coil part
220W3: 3W phase coil part
220W4: 4W phase coil unit
220U: U-phase coil unit
220U1: 1U phase coil unit
220U2: 2U phase coil unit
220U3: 3U phase coil unit
220U4: 4U phase coil unit
220V: V phase coil part
220V1: 1V phase coil part
220V2: 2V phase coil part
220V3: 3V phase coil part
220V4: 4V phase coil part
222U1: first coil unit
222U2: second coil unit
222U3: third coil unit
222U4: fourth coil unit
230: neutral wire
300: hairpin
301: conductor
303: insulation coating
310: connection part
320: insertion part
330: protrusion
331: inclined part
3310: one end of the slope
333: connection part
3330: peeling part
300a: first hairpin (voltage sharing hairpin)
300b: second hairpin
330a1: first protrusion
331a1 first slope
3310a1: one end of the first inclined part
333a1: first connection part
3330a1: the first peeling part
3331a1: first molten upper surface
3332a1: first moult side
330a2: second protrusion
331a2: second inclined portion
3310a2: one end of the second inclined part
333a2: second connection part
3330a2: second peeling part
3331a2: second molten upper surface
3332a2: the second molting side
330b1: first protrusion
331b1 first slope
3310b1: one end of the first inclined part
333b1: first connection part
3330b1: the first peeling part
3331b1: first molten upper surface
3332b1: first moult side
330b2: second protrusion
331b2: second inclined portion
3310b2: one end of the second inclined part
333b2: second connection part
3330b2: second peeling part
3331b2: second molten upper surface
3332b2: the second moulting side
400: fixing member
410: fixed hole
500: friction member
510: first friction member
520: second friction member
610: bead
620: bead
630: bead
C: coil pair
CCP: Current

Claims (15)

a stator core having a plurality of slots; and
and a stator coil formed to connect a plurality of hairpins inserted into the slot in a preset pattern,
The hairpin includes a conductor and an insulating coating surrounding the conductor,
A plurality of the hairpins are inserted into each of the plurality of slots and are sequentially arranged along the radial direction of the stator core,
A stripping powder from which the insulating coating is removed by a predetermined length is formed on an end portion protruding toward one side of the stator core among the plurality of hairpins,
The stripping parts of the plurality of hairpins are sequentially arranged along the radial direction of the stator core,
Among the stripping parts arranged sequentially, the stripping part arranged in the 2n-1th order and the stripping part arranged in the 2nth order are joined to each other to form a plurality of coil pairs,
wherein n is a natural number,
The stripping parts constituting the coil pair are joined to each other by friction stir welding,
stator. According to claim 1,
A fixing member is disposed on one side of the stator core before the friction stir welding is performed,
A plurality of fixing holes are formed through the fixing member at positions corresponding to the plurality of pairs of coils,
A plurality of the coil pairs are inserted into the plurality of fixing holes,
The circumferential surfaces of the plurality of pairs of coils are pressed by a fixing member and fixed in the radial direction of the stator core,
stator. 3. The method of claim 2,
The friction stir welding is performed by rotating or vibrating friction members in contact with both surfaces of the stator core facing the circumferential direction of the coil pair,
Among the plurality of coil pairs, the coil pairs overlapping in the radial direction of the stator core are in contact with the friction member at the same time,
stator. 3. The method of claim 2,
The friction stir welding is performed by rotating or vibrating a friction member in contact with one side of the coil pair facing the axial direction of the stator core,
A plurality of the coil pairs are in contact with the friction member at the same time,
stator. 5. The method of claim 3 or 4,
wherein the friction member vibrates in a radial direction of the stator core,
stator. (a) inserting a plurality of hairpins into each of a plurality of slots formed through the stator core and sequentially arranging them in a radial direction of the stator core;
(b) forming a stripped portion by removing the insulating coating of an end portion protruding toward one side of the stator core among the plurality of hairpin portions by a predetermined length;
(c) sequentially arranging the plurality of hairpin parts in a radial direction of the stator core;
(d) forming a plurality of pairs of coils by contacting the stripping part arranged in the 2n-1st order and the stripping part arranged in the 2n-th order among the stripping parts sequentially arranged; and
(e) coupling a plurality of the coil pairs by friction stir welding;
Wherein n is a natural number,
A method of manufacturing a stator. 7. The method of claim 6,
The step (c) is,
(c1) bending a portion of the plurality of hairpins protruding toward one side of the stator core by a predetermined angle in a clockwise or counterclockwise direction; and
(c2) bending the plurality of hairpins in the axial direction so that the portions in which the skin parts are formed overlap along the radial direction of the stator core,
A method of manufacturing a stator. 7. The method of claim 6,
Step (d) is,
(d1) fixing the skin parts in contact with each other using a fixing member so as not to move arbitrarily along the radial direction of the stator core; and
(d2) of the plurality of parts of the coil pair, grinding one side facing the axial direction of the stator core to remove the step difference between the peeling parts in contact with each other constituting the coil pair,
A method of manufacturing a stator. 7. The method of claim 6,
Step (e) is,
(e1) contacting the friction member with one side of the coil pair facing the axial direction of the stator core;
(e2) vibrating or rotating the friction member while in contact with the one surface facing the axial direction; and
(e3) comprising the step of heating and bonding the skin parts that are in contact with each other constituting the coil pair,
A method of manufacturing a stator. 10. The method of claim 9,
A plurality of the coil pairs are simultaneously joined by vibration or rotation of the friction member,
A method of manufacturing a stator. 7. The method of claim 6,
Step (e) is,
(e1) contacting the friction member with both sides of the coil pair facing the circumferential direction of the stator core;
(e2) vibrating or rotating the friction member while in contact with the both surfaces; and
(e3) comprising the step of heating and bonding the skin parts that are in contact with each other constituting the coil pair,
A method of manufacturing a stator. 12. The method of claim 9 or 11,
The friction member is in contact with the plurality of coil pairs overlapping in the radial direction of the stator core at the same time,
The coil pairs overlapping in the radial direction of the stator core are simultaneously joined by vibration or rotation of the friction member,
A method of manufacturing a stator. 7. The method of claim 6,
Step (e) is,
(e1) contacting a first friction member with one side of the coil pair facing the axial direction of the stator core;
(e2) vibrating or rotating the first friction member while in contact with the one surface facing the axial direction;
(e3) contacting a second friction member with both sides of the stator core facing the circumferential direction of the coil pair;
(e4) vibrating or rotating the second friction member while in contact with the both surfaces; and
(e5) comprising the step of heating and bonding the skin parts in contact with each other constituting the coil pair,
A method of manufacturing a stator. 7. The method of claim 6,
(f) removing the bead (bead) formed on the part to which the skin removal component is joined,
The bead is removed by milling (milling) treatment,
A method of manufacturing a stator. 15. The method of claim 14,
(g) subjecting a plurality of bonded coil pairs to a stress relief heat treatment;
A method of manufacturing a stator.

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