JP2020068569A - Rotating electric machine stator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stator of a rotating electric machine capable of suppressing an increase in manufacturing cost and a decrease in space factor of a slot while ensuring a sufficient insulation performance.
SOLUTION: Each conductor segment 31 included in a stator 2 has a conductor element wire 34 made of a conductor and an insulating coating 35 covering the periphery of the conductor element wire 34. The stator has a slot 17a in which two or more conductor segments 31a and 31b in which at least one of the dielectric constant and the film thickness of the insulating coating is different are accommodated, and a slot in which all the conductor segments accommodated are substantially the same. When two or more exist, the two or more slots satisfy at least one of the plurality of slots in which at least one of the dielectric constant and the film thickness of the insulating coating in the accommodated conductor segment is different. .
[Selection diagram] Fig. 3

Description

  The present invention relates to a stator of a rotary electric machine.

  BACKGROUND ART Conventionally, as a stator of a rotary electric machine, there is one described in Patent Document 1. This stator includes a stator core, a coil, and a slot insulator. The stator core has an annular yoke and a plurality of teeth. The plurality of teeth are spaced apart from each other in the circumferential direction, and each of the teeth protrudes radially inward from the yoke. The slot insulator is arranged along the peripheral wall of the slot, which is the space between the adjacent teeth. Further, the coil is inserted into a slot, which is a space between adjacent teeth, and is wound around the tooth via a slot insulator. The coil has an in-slot conductor arranged in the slot, a coil end conductor arranged outside the slot, and an insulating coating film covering these conductors. In this stator, the dielectric constant and film thickness of the insulating film of the coil are different from the dielectric constant and film thickness of the slot insulator. In this way, the discharge start voltage proportional to the (thickness t of the insulating coating / dielectric constant ε of the insulating coating) raised to the 0.46th power is increased to secure the insulating performance in the slot while occupying the space in the slot. The rate is increasing.

JP, 2014-87101, A

  The local stress that acts on the insulating coating changes depending on the installation location, and more specifically, it changes depending on the shared voltage of the conductor wires covered by the insulating coating and the temperature of the insulating coating. As the insulating coating of the coil, a material having a material and a film thickness that can withstand the most stress is used as a reference. However, in this structure, the insulating property of the insulating coating becomes excessive with respect to the insulating property required to prevent discharge in a place where the stress acting is small, which increases the manufacturing cost and the space factor of the slot. It is easy to cause deterioration.

  Therefore, an object of the present invention is to provide a stator for a rotary electric machine that can suppress an increase in manufacturing cost and a decrease in space factor of slots while ensuring sufficient insulation performance.

  In order to solve the above problems, a stator of a rotary electric machine according to the present invention includes an annular yoke, and a plurality of teeth protruding inward in the radial direction from the yoke in a state of being spaced from each other in the circumferential direction of the yoke. A stator of a rotating electric machine, comprising: a stator core having slots provided between teeth adjacent to each other in the circumferential direction; and a coil wound around the teeth and including a plurality of spirally joined conductor segments. Each of the conductor segments has a conductor element wire made of a conductor and an insulating film covering the periphery of the conductor element wire, and at least one of the dielectric constant and the film thickness of the insulating film is different. There is the slot in which the conductor segment is accommodated, and there are two or more slots in which all the conductor segments accommodated are substantially the same. In case the two or more slots, at least one of the dielectric constant and thickness of the insulating coating of the conductor segments are accommodated satisfies at least one of including a plurality of different said slots.

  The difference in the phrase "the dielectric constant and / or the film thickness of the insulating film is different" means that the value exceeds the tolerance (design error) that occurs when the same product is intended to be manufactured. Shall mean.

  In addition, the condition of "substantially the same" in the phrase "the conductor segments are substantially the same" has a difference within a tolerance (design error) that occurs when it is intended to manufacture the same thing. The case shall be met.

  In addition, in the present specification, when the word "different" is used, it means a difference exceeding the range of the tolerance, and when the word "substantially the same" is used, the condition is within the tolerance. Even if there is a difference in

  In the present invention, a plurality of the insulations each including a lead wire for supplying at least one of the power supply from the outside to the coil and the power supply from the coil to the outside are included in the plurality of conductor segments. The coating includes one or more first insulating coatings having a property of least conducting electricity, and one or more second insulating coatings more easily conducting electricity than the first insulating coating, and the conductor segment including the lead wire. It is preferable that the insulating coating is a first insulating coating.

  Further, in the present invention, a plurality of the coils wound around the stator core is provided with a lead wire for at least one of supplying power from the outside to the coil and supplying power from the coil to the outside. The plurality of insulating coatings included in includes one or more first insulating coatings having a property of least conducting electricity and one or more second insulating coatings more easily conducting electricity than the first insulating coatings, and is housed. There are two or more slots having substantially the same insulating properties of the insulating coatings of all the conductor segments, and the insulating coatings of the accommodated conductor segments have the first insulating in the two or more slots. A first slot which is a coating, and a second slot in which the insulating coating of the contained conductor segment is the second insulating coating is included, and the conductor segment including the lead wire is Preferably housed in serial first slot.

  According to the stator of the rotating electric machine of the present invention, the insulating property of the insulating coating of the conductor segment can be changed based on the local stress acting on the insulating coating. Therefore, it is possible to improve the insulation properties of the places where the stress is high, while decreasing the insulation properties of the places where the stress is low. Therefore, for example, the film thickness of the insulating film can be changed based on the local stress acting on the insulating film, so that the manufacturing cost is increased and the space factor of the slot is decreased while securing sufficient insulating performance. Can be suppressed.

It is a perspective view of the stator of the rotary electric machine which concerns on one Embodiment of this invention. It is a front view of the conductor segment which the above-mentioned stator contains. FIG. 7 is an enlarged schematic cross-sectional view of the periphery of a slot in the stator, which is a part of the schematic cross-sectional view when the stator is cut along a plane including a radial direction and a circumferential direction. FIG. 9 is an enlarged schematic cross-sectional view corresponding to FIG. 3 in a stator of a modification. It is a schematic plan view when a further deformable stator is seen from one side in the height direction. FIG. 8 is an enlarged schematic cross-sectional view of a slot peripheral portion included in a first region in the circumferential direction corresponding to FIG. 3 in the stator of the further modification. FIG. 8 is an enlarged schematic cross-sectional view of a slot peripheral portion included in a second region in the circumferential direction corresponding to FIG. 3 in the stator of the further modification.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. When a plurality of embodiments and modifications are included in the following, it is assumed from the beginning that a new embodiment is constructed by appropriately combining the characteristic parts. Further, in the following embodiments, the same reference numerals are given to the same components in the drawings, and duplicated description will be omitted. Further, a plurality of drawings include schematic drawings, and the dimensional ratios of the respective members such as length, width, height, etc. do not necessarily match between different drawings. Further, in the following description and drawings, the θ direction indicates the circumferential direction of the annular stator core, the R direction indicates the radial direction of the annular stator core, and the Z direction indicates the height direction of the stator core. The θ direction, the R direction, and the Z direction are orthogonal to each other.

  FIG. 1 is a perspective view of a stator 2 of a rotary electric machine 1 according to an embodiment of the present invention. As shown in FIG. 1, the stator 2 includes a stator core 11 and a stator coil 15 including a rectangular wire. The stator core 11 is an annular magnetic component, and is formed by stacking a plurality of silicon steel plates (electromagnetic steel plates), for example, but may be formed by pressure molding a resin binder and magnetic material powder. Good. The stator core 11 has an annular yoke 12 arranged on the outer peripheral side and a plurality of teeth 16. The plurality of teeth 16 are arranged at intervals in the θ direction, and each tooth 16 projects inward from the yoke 12 in the R direction. Slots 17 are provided between the teeth 16 adjacent in the θ direction. The stator coil 15 includes a plurality of U-, V-, and W-three-phase coils that are helically wound so as to straddle the same plurality of teeth 16 while alternately passing through the two slots 17.

  A plurality of coils of the same phase are connected in series to form a linked coil body. The linked coil body of each phase is, for example, distributedly wound around the plurality of teeth 16 over the plurality of teeth 16 over one or two turns in the θ direction. For example, when the connected coil body of each phase is distributed and wound in two directions in the θ direction, the connected coil body of each phase is a first connected coil body and a second connected coil body serially connected to the first connected coil body. Have. The first connection coil body is distributed and wound around the plurality of teeth 16 over the plurality of teeth 16 in one direction in the θ direction, and the second connection coil body is also formed of the plurality of teeth 16 so as to extend over the plurality of teeth 16. 16 is distributed and wound in one direction in the θ direction. Even if the connecting coil bodies of each phase are wound around the plurality of teeth 16 so that the slot 17 through which the second connecting coil body passes is offset by one in the θ direction with respect to the slot 17 through which the first connecting coil body passes. Good. One end of each of the three-phase U, V, and W connected coil bodies is Y-connected or Δ-connected to form the stator coil 15. On the other hand, the other ends of the U-, V-, and W-phase three-phase linked coil bodies are drawn out to the outer peripheral side in the R direction with respect to the stator core 11 to form lead wires 22U, 22V, 22W. The lead lines 22U, 22V, 22W of each phase are electrically connected to the corresponding power lines (not shown) of each phase.

  Each of the U, V, and W three-phase coils is composed of a segment coil formed by welding a plurality of conductor segments in series. FIG. 2 is a front view of the conductor segment 31. Each coil is formed as follows. Specifically, first, a plurality of substantially U-shaped conductor segments 31 are prepared. Each conductor segment 31 includes two leg portions 32 that are parallel to each other and one end portion of each leg portion 32 that is connected to each other and that has a connecting portion 33 having a chevron shape. Each conductor segment 31 is formed by covering an intermediate portion other than both ends of the conductor wire 34, which is formed of a conductor having a rectangular cross section and a rectangular shape, with an insulating coating 35 to expose both ends of the conductor wire 34. . The conductor wire 34 and the insulating coating 35 that covers the periphery of the conductor wire 34 form a rectangular wire 38.

  With reference to FIGS. 1 and 2, the plurality of conductor segments 31 are inserted in the same two slots 17 from the other side in the Z direction (lower side in FIG. 1) of the stator core 11 while being aligned in the R direction. Then, the leg portion 32 of the conductor segment 31 of each coil bends the stator core side of the protruding portion protruding outward from the Z direction one end surface (upper end surface in FIG. 1) of the stator core 11. In this embodiment, the tip of the protruding portion exposed from the insulating coating 35 is not bent and extends outward in the Z direction.

  Regarding the plurality of conductor segments 31 overlapping in the R direction, in the two conductor segments 31 adjacent to each other in the R direction, the tip portion on one side in the θ direction of one conductor segment 31 is bent to the other side in the θ direction, and the other conductor segment 31 The tip of 31 on the other side in the θ direction is bent to one side in the θ direction. The tip portion of the one conductor segment 31 on the one side in the θ direction is joined and connected to the tip portion of the other conductor segment 31 on the other side in the θ direction by TIG welding, resistance welding, laser welding, or the like. . As a result, the plurality of conductor segments 31 overlapping in the R direction are spirally connected to each other to form a coil. The coils are wound around the plurality of teeth 16 with a part of both ends in the θ direction of each coil being inserted into the two slots 17.

  In each coil, the leg portions 32 of the two conductor segments 31 arranged at both ends in the R direction of the stator 2 are bent to the side of another coil adjacent in the θ direction. Then, in the coils adjacent to each other in the θ direction, the tip ends of the leg portions 32 of the two conductor segments 31 arranged at the end portions in the R direction are joined by welding. As a result, the conductor segments 31 of the same phase adjacent in the θ direction are connected in series, and the coils of the same phase adjacent in the θ direction are connected in series.

  Again with reference to FIG. 1, a rotor (not shown) is arranged on the inner peripheral side of the stator 2 with a distance from the stator 2. The centers of the stator 2 and the rotor coincide. The rotor is an annular magnetic component fixed around the rotating shaft, and is formed by stacking, for example, a plurality of annular silicon steel plates (electromagnetic steel plates). In the rotor, for example, a plurality of permanent magnets are embedded in the θ direction at intervals. When the rotating electric machine 1 is driven, for example, after the direct current from the battery is converted into the three-phase alternating current through the inverter, the three-phase alternating current passes through the three-phase power lines U, V, and W. It is supplied to the three-phase coils of U, V, and W via. By supplying the three-phase alternating current to the U-, V-, and W-three-phase coils, the teeth 16 are magnetized to become magnetic poles, and a rotating magnetic field in which the magnetic pole positions move in the θ direction of the stator 2 is generated. Then, the rotor rotates based on the rotating magnetic field, and rotational power is generated.

  On the other hand, when regenerating electric power, when the rotor is rotated by power from the outside, the permanent magnet embedded in the rotor rotates around the rotor central axis. Then, an induced electromotive force based on the law of electromagnetic induction is induced in the U, V, W three-phase coils, and an AC induced current flows in the U, V, W three-phase coils, and then U, V, It flows through the three-phase power line of W. Then, the AC power from the three-phase coils of U, V, and W based on the induced current is converted into DC power by the inverter and then supplied to the battery or the like. The stator 2 has a plurality of mounting portions 36 arranged at intervals in the θ direction, and each mounting portion 36 bulges outward in the R direction. The stator 2 is attached to the case by passing a bolt (not shown) through the fastening hole 37 of the attachment portion 36 and then fixing the bolt to an axial end surface of the case (not shown).

  FIG. 3 is a part of a schematic cross-sectional view when the stator 2 is cut along a plane including the R direction and the θ direction, and is an enlarged schematic cross-sectional view around the slot 17 in the stator 2. In addition, in the paper surface of FIG. 3, the lower side corresponds to the inner side in the R direction (rotor side).

  As shown in FIG. 3, in the slot 17, a plurality of rectangular wires 38 are arranged so as to overlap in the R direction. In the slot 17, the conductor wire 34 of the stator coil 15 is not exposed from the insulating coating 35 and is covered with the insulating coating 35 over the entire circumference. In other words, the slot arrangement portion 40 arranged in the slot 17 in each conductor segment 31 has the conductor element wire 34 and the insulating coating 35 that covers the periphery of the conductor element wire 34.

  As shown in FIG. 3, the stator 2 has a slot 17a in which two or more different conductor segments 31a and 31b are accommodated. In the present embodiment, the six conductor segments 31 housed in the slots 17a are arranged such that one first conductor segment 31a arranged at the outermost side in the R direction and one inner side in the R direction further than the first conductor segment 31a. It has five substantially identical second conductor segments 31b different from the segment 31a.

  In general, the local stress that acts on the insulating coating fluctuates depending on the installation location, and more specifically, it depends on the shared voltage of the conductor wires covered by the insulating coating and the temperature of the insulating coating. fluctuate. The local stress differs depending on the specifications of the rotating electric machine, and the local stress is calculated by, for example, computer simulation. When conducting a qualitative discussion, a conductor segment close to the power line on the power source side tends to have a high shared voltage of the conductor wires, and such a conductor segment preferably has an insulating coating having high insulation properties. . In addition, as the temperature rises, generally, the resistance of the insulating coating tends to decrease and the withstand voltage tends to decrease accordingly. Therefore, it is preferable that the conductor segment in the portion where the cooling oil for cooling the stator coil is hard to be applied has an insulating coating having a high insulating property. Further, the insulating coating in such a place is likely to be thermally deteriorated, and for that reason also, it is preferable that the insulating coating has a high insulating property.

  In this embodiment, in the slot 17a, the shared voltage of the first conductor segment 31a located most outward in the R direction is higher than that of the other second conductor segments 31b in the slot 17a. explain. In such a background, in the present embodiment, the conductor wire 34 of the first conductor segment 31a substantially matches the conductor wire 34 of the second conductor segment 31b, while the first insulating coating 35a of the first conductor segment 31a is It is different from the second insulating coating 35b of the second conductor segment 31b. More specifically, the film thickness of the first insulating film 35a is substantially the same as the film thickness of the second insulating film 35b, but the dielectric constant of the first insulating film 35a is lower than the dielectric constant of the second insulating film 35b. As a result, the first insulating coating 35a has a better insulating property than the second insulating coating 35b.

  As described above, according to the present embodiment, the stator 2 has the slot 17a in which two or more conductor segments 31a and 31b having different dielectric constants of the insulating coatings 35a and 35b are accommodated. Therefore, when there are two or more conductor segments 31a, 31b having different acting stresses in the plurality of conductor segments 31 housed in the one or more slots 17a, the insulation property of the insulating coating 35 is adjusted according to the stress. Can be designed optimally, and more specifically, the insulating property of the first insulating coating 35a of the first conductor segment 31a having high stress can be improved, while the insulating property of the second insulating coating 35b of the second conductor segment 31b having low stress can be improved. Can be lowered. Therefore, for example, it is possible to reduce the film thickness of the second insulating coating 35b with low stress while ensuring sufficient insulation performance, and as a result, increase manufacturing cost and increase the number of slots while ensuring sufficient insulation performance. The decrease in space factor can be suppressed.

  Furthermore, according to the technique of the present disclosure, the insulating property of the insulating coating 35 can be changed for each conductor segment 31. Therefore, in that case, the conductor segments 31a and 31b are formed in comparison with the case where a conductor segment in which the insulating property of the insulating film in the portion accommodated in the slot is different from the insulating property of the insulating film in the portion protruding from the slot is used. Easy to divide. Therefore, the conductor segments 31a and 31b can be formed easily and inexpensively, and the stator 2 can also be easily and inexpensively manufactured.

  It should be noted that the present invention is not limited to the above-described embodiments and modifications thereof, and various improvements and changes can be made in the matters described in the claims of the present application and equivalent ranges thereof.

  For example, in the above embodiment, the case where the insulating coating 35 of the conductor segment 31 directly contacts the inner surface of the slot 17 in the stator core 11 has been described. However, an insulating part made of insulating paper or the like may be arranged between the slot defining surface that defines the slot in the stator core and the insulating coating of the conductor segment. It may be possible to reliably prevent the strands from short-circuiting with the metal stator core.

  Further, the case has been described in which the insulating performance of the insulating coating 35 is changed by changing the types of the insulating coatings 35a and 35b in the two or more conductor segments 31a and 31b arranged in the same slot 17a. However, as shown in FIG. 4, that is, an enlarged schematic cross-sectional view corresponding to FIG. 3 in the stator 102 of the modified example, in the two or more conductor segments 131a and 131b housed in the same slot 117a, the insulating coating made of the same material is used. The insulating performance of the insulating coatings 135a and 135b may be changed by changing the film thickness of the 135a and 135b. Alternatively, although not shown, the insulating performance of the insulating coating may be changed by changing both the type and the film thickness of the insulating coating in two or more conductor segments housed in the same slot.

  Moreover, the case where the stresses acting on the two or more conductor segments 31a and 31b arranged in the same slot 17a are different has been described. However, as described above, in the stator, the shared voltage in the circumferential area close to the power line is likely to be larger than the shared voltage in the circumferential area far from the power line, and the stress in the circumferential area near the power line is It is likely to be larger than the stress in the circumferential area far from the line. Further, in the stator, the degree of splash of cooling oil may vary in the circumferential direction. In such a case, two or more slots in which all the accommodated conductor segments are substantially the same are formed, and the two or more slots are at least the dielectric constant and the film thickness of the insulating coating in the accommodated conductor segments. A plurality of slots, one of which may be different, may be included.

  More specifically, as shown in FIG. 5, that is, a schematic plan view of the further deformable stator 202 viewed from one side in the Z direction, the stator 202 is included in the first region R1 within the first range in the θ direction. In each of all the slots provided, all the conductor segments accommodated in each slot may be the same. In addition, even in each of all the slots included in the second region R2 which is located at a distance in the θ direction with respect to the first region R1 and falls within the second range in the θ direction, all the slots accommodated in each slot. The conductor segments may be the same. Then, the insulating properties of the insulating coatings of the conductor segments included in the first region R1 may be different from the insulating properties of the insulating coatings of the conductor segments included in the second region R2.

  For example, a case where the stress acting on each conductor segment arranged in the first region R1 is larger than the stress acting on each conductor segment arranged in the second region R2 will be described with reference to FIG. 6, that is, further deformation. As shown in an enlarged schematic cross-sectional view corresponding to FIG. 3 in the peripheral portion of the slot included in the first region R1 in the example stator 202, each conductor segment 231a accommodated in the slot 217a includes a conductor wire 234, You may have the insulating coating 235a which surrounds the side surface over the perimeter. Further, as shown in FIG. 7, that is, an enlarged schematic cross-sectional view corresponding to FIG. 3 in the slot peripheral portion included in the second region R2 in the stator 202, each conductor segment 231b accommodated in the slot 217b is You may have the strand 234 and the insulating coating 235b which surrounds the side surface over the perimeter. The material of the insulating coating 235a may be different from the material of the insulating coating 235b, and the insulating property of the insulating coating 235a may be higher than the insulating property of the insulating coating 235b. In this way, by changing the insulating coatings 235a and 235b of the conductor segments in units of the circumferential direction, it is possible to suppress an increase in manufacturing cost and a decrease in space factor of the slot while ensuring sufficient insulating performance. . When the insulating coating of the conductor segment is changed in the circumferential direction, the thickness of the insulating coating may be changed instead of changing the type of the insulating coating. When the insulating coating of the conductor segment is changed in the circumferential direction, both the type and the film thickness of the insulating coating may be changed at different positions in the circumferential direction.

  Further, the case where the insulating coating is changed for a plurality of conductor segments accommodated in the same slot and the case where the insulating coating of the conductor segment is changed for each circumferential direction have been described. However, the stator has one or more slots for accommodating a plurality of conductor segments including two or more conductor segments having different insulation properties of the insulating coating, and that all the accommodated conductor segments have substantially the same slot. When two or more slots are present, the two or more slots may both satisfy a plurality of slots in which at least one of the dielectric constant and the film thickness of the insulating coating in the accommodated conductor segment is different.

  Further, as described above, in the stator, the shared voltage in the circumferential region near the power line tends to be larger than the shared voltage in the circumferential region far from the power line. Therefore, the stator of one embodiment includes a lead wire for supplying at least one of the power supply from the outside to the coil and the power supply from the coil to the outside, and the plurality of insulating coatings included in the plurality of conductor segments. Includes one or more first insulating coatings having the property of least conducting electricity and one or more second insulating coatings more likely to conduct electricity than the first insulating coating, and the insulating coating of the conductor segment including the lead wire is The first insulating film is preferable.

  A stator according to another embodiment includes a lead wire for supplying at least one of electric power supplied to the coil from the outside and electric power supplied from the coil to the outside, and a plurality of coils wound around the stator core. The plurality of insulating coatings included in 1 may include one or more first insulating coatings that have the property of least conducting electricity, and one or more second insulating coatings that more easily conduct electricity than the first insulating coatings. Further, in the stator, there are two or more slots in which the insulating coatings of all the accommodated conductor segments have substantially the same insulating properties, and the two or more slots have the insulating coatings of the accommodated conductor segments as the first. The first slot, which is an insulating coating, and the insulating coating of the contained conductor segment may include a second slot, which is a second insulating coating. The conductor segment including the lead wire is preferably housed in the first slot. In any of these cases, the plurality of insulating coatings included in the plurality of conductor segments may have only two different insulating coatings, or may have three or more different insulating coatings.

  1 rotary electric machine, 2,102,202 stator, 11 stator core, 12 yoke, 15 stator coil, 16 teeth, 17,17a, 117a, 217a, 217b slot, 31,31a, 31b, 131a, 131b, 231a, 231b conductor segment , 34,234 conductor strands, 35,35a, 35b, 135a, 135b, 235a, 235b insulating coating, θ direction circumferential direction, R direction radial direction, Z direction height direction.

Claims (1)

A stator core having an annular yoke and a plurality of teeth protruding inward in the radial direction from the yoke while being spaced from each other in the circumferential direction of the yoke, and having slots provided between the teeth adjacent in the circumferential direction. When,
A stator of a rotating electric machine comprising: a coil that is wound around the teeth and that includes a plurality of conductor segments that are spirally joined;
Each of the conductor segments has a conductor wire made of a conductor and an insulating coating that covers the periphery of the conductor wire,
It has the slot in which two or more conductor segments different in at least one of the dielectric constant and the film thickness of the insulating coating are accommodated, and the slot in which all the conductor segments accommodated are substantially the same. In the case where the two or more slots are present, the two or more slots satisfy at least one of the plurality of slots in which at least one of the dielectric constant and the film thickness of the insulating coating in the accommodated conductor segment is different, Electric machine stator.

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