JP2012090441A - Conductive wire coated with insulating film, and rotary electric machine - Google Patents

Abstract

An object of the present invention is to improve a space factor in a structure in which an insulating film part is formed on a conductor part of a conductor with an insulating film.
A conductor portion 52 of a coil winding 50 has a cross-sectional shape in which each side is curved outward while the basic cross-sectional shape is rectangular. Specifically, given the curvature of radius of curvature R ₁ in the long side of the rectangular shape, given the curvature of radius of curvature R ₂ in the short side. The radius of curvature R ₁ , R ₂ is such that the thickness of the insulating coating 54 at the corner of the conductor 52 is the same as the thickness of the insulating coating 54 at each side. Is set in consideration of the surface tension. In other words, when another coil winding is stacked on the coil winding 60, the insulating film portion between the center portion of each side surface of the adjacent conductor portion and the center portion of each side surface of the adjacent conductor portion facing this. R ₁ and R ₂ are set so that the distance L between them is the shortest.
[Selection] Figure 5

Description

  The present invention relates to a conductive wire with an insulating film and a rotating electric machine, and more particularly, to a conductive wire with an insulating film for coil winding formed by forming an insulating film portion on a conductor and a rotating electric machine using the same. .

  Coil windings called stator windings or armature windings are arranged on the stator of the rotating electric machine. The stator includes a stator core in which projecting portions called teeth are arranged along the circumferential direction, and a winding portion. The winding portion includes a slot winding in which a coil winding is inserted into a space between adjacent teeth of the stator core, and the coil winding is wound around the teeth in a predetermined manner. And a coil end portion drawn out of the stator core from the slot.

  Since the coil windings are arranged so as to overlap each other in the slot and at the coil end portion, improvement in insulation performance and improvement in volumetric efficiency of stacking are required.

  For example, in Patent Document 1, as a method of forming an armature winding that is housed together with an insulating sheet in a slot of a stator of a rotating electrical machine, a round cross-section covered electric wire having a uniform insulating film thickness is formed with a rolling roller. It is disclosed that the upper and lower surfaces are flattened by pressing from above and below to form a sectioned drum-shaped winding in which the film thickness of the insulating film on the upper and lower surfaces is smaller than the film thickness of the insulating film on the arcuate side surface. It is stated that the dead space in the slot can be reduced by doing so. Insulating performance can be secured with an insulating sheet even when the upper and lower insulating films are thin.

  Further, Patent Document 2 does not use an insulating film, but when a magnet wire insulated by an insulating tape is a square or rectangular magnet wire, the magnet wire is bent at 90 degrees and wound. Further, it is described that plastic deformation occurs and the cross-sectional shape becomes trapezoidal and damages the insulating tape. Here, it is stated that the cross-sectional shape of the conductor does not become a trapezoidal shape even when plastically deformed by setting both edges of a radius of curvature equal to or larger than the wire thickness.

JP-A-6-189482 JP-A-6-44828

  The volumetric efficiency of stacking coil windings can be expressed, for example, by the space factor, which is the ratio of the volume of the coil winding conductor to the slot volume space. It is conceivable to arrange adjacent coil windings so that the cross-sectional shape of the line is rectangular and the flat sides of the rectangle are in contact with each other. In this case, as a method of forming the insulating film portion on the conductor portion having a rectangular cross section, a method in which an insulating varnish is applied on the conductor portion and then baking treatment is performed, or a fluid is temporarily formed using a thermoplastic resin. When the method of covering the surface of the conductor part and then solidifying the conductor part is taken, the insulating film part is not necessarily formed in a rectangular shape with a uniform thickness due to the surface tension of the fluid. In this way, if the insulating film part is not uniform thickness, even if the conductor part is made a rectangular shape, the outer shape does not become a rectangular shape, so when this is stacked in a slot, for example, between adjacent coil windings, A gap is formed between the coil winding and the inner wall of the slot, and the space factor decreases.

  An object of the present invention is to provide a conductive wire with an insulating film capable of improving the space factor in a structure in which an insulating film part is formed on a conductor part, and a rotating electrical machine using the same.

  A conductive wire with an insulating coating according to the present invention is a conductive wire with an insulating coating for a coil winding that is sequentially wound around a winding frame, and a conductor portion having a polygonal basic cross-sectional shape; And an insulating film portion made of a thermoplastic resin, and the conductor portion faces the central portion of each side surface of the conductor portion between adjacent conductor portions when wound. Each side of the basic cross-sectional shape has a curved cross-sectional shape so that the distance between the central portions of the side surfaces of adjacent conductor portions between the insulating film portions is the shortest.

  Moreover, in the conductor with an insulating film according to the present invention, the insulating film part is preferably formed of a thermoplastic resin.

  Further, in the conductor with an insulating film according to the present invention, the size of each of the sides of the conductor part is determined by the thickness of the thermoplastic resin at the polygonal corners of the conductor part and the thermoplastic resin at each side. It is preferable to set in advance based on the difference in thickness.

  Moreover, in the conducting wire with an insulating film according to the present invention, the conductor portion preferably has a square or rectangular basic cross-sectional shape.

  Further, a rotating electrical machine according to the present invention includes a rotor that is a rotor attached to a rotor shaft, and a stator that is provided on the outer peripheral side of the rotor and that is a stator including a conductive wire with an insulating film for coil winding. The conductor with an insulating film includes a conductor portion having a polygonal basic cross-sectional shape, and an insulating film portion provided on the conductor portion and made of a thermoplastic resin. The distance between the center portion of each side surface of the conductor portion and the center portion of each side surface of the adjacent conductor portion facing the conductor portion between adjacent conductor portions when being wired is minimized. In addition, each side of the basic cross-sectional shape has a curved cross-sectional shape.

  With the above configuration, the conductor portion of the conductive wire with an insulating film has a central portion of each side surface of the conductor portion and a central portion of each side surface of the adjacent conductor portion facing this between adjacent conductor portions when wound. Each side of the basic cross-sectional shape has a curved cross-sectional shape so that the distance between which the insulating film portion is sandwiched is the shortest. Thereby, for example, when an insulating film part is formed on the conductor part, even if the conductor part has a tendency to become thicker at the corners of the cross-sectional shape of the conductor part and thinner at the side parts due to surface tension, etc. Due to the curved cross section, the outer shape of the coil winding is substantially polygonal, and it is possible to suppress the formation of a gap between the adjacent coil winding, the inner wall of the slot, and the coil winding.

  In the conductor with an insulating film, when the insulating film part is formed of a thermoplastic resin, it tends to be thick at the corners of the cross-sectional shape of the conductor part due to fluidity, etc., and thin at the side part due to fluidity. Due to the curved cross section of the conductor portion, the outer shape of the coil winding is substantially polygonal, and the occurrence of a gap between the adjacent coil winding, the inner wall of the slot, and the coil winding can be suppressed.

  Moreover, in the conductor with an insulating film, the magnitude of the curvature of each side of the conductor part is the difference between the thickness of the thermoplastic resin at the polygonal corner of the conductor part and the thickness of the thermoplastic resin at each side. Therefore, it is possible to effectively suppress the occurrence of a gap between the adjacent coil windings, the inner wall of the slot, and the coil windings.

  Further, in the conductor with an insulating film, the conductor portion has a square or rectangular basic cross-sectional shape, so that, for example, the space factor in the slot can be improved.

It is a figure which shows the mode of the rotary electric machine in which the conducting wire with the insulation film for coil windings of embodiment which concerns on this invention is used. It is a figure which extracts and shows the stator in FIG. It is a figure which shows a mode that the A section in FIG. 2 was seen from the internal diameter side. It is a figure which shows the mode of the cross section along the SS line | wire of FIG. It is a figure which shows the cross-sectional shape of the coil winding of embodiment which concerns on this invention. As a comparison, it is a figure which shows the cross-sectional shape of a coil winding whose conductor part is a rectangular shape.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, a combination of a permanent magnet type rotor and a stator having a stator winding will be described as a rotating electric machine, but the rotor may be of a type other than the permanent magnet type, for example, a reluctance type rotor. In the following, the rotor core and the stator core will be described by laminating electromagnetic steel sheets, but materials other than the electromagnetic steel sheets may be used, for example, powder molding or the like may be used. .

  In the following description, the insulating film portion is described as being formed of a thermoplastic resin on the conductor portion, but the thermoplastic resin may be composed of a plurality of layers, and the conductor portion and the thermoplastic resin may be formed. An intermediate layer such as an enamel layer may be provided therebetween, and an adhesive layer may be provided on the surface of the thermoplastic resin.

  Below, the same code | symbol is attached | subjected to the same element in all the drawings, and the overlapping description is abbreviate | omitted. In the description in the text, the symbols described before are used as necessary.

  FIG. 1 is a diagram illustrating a configuration of the rotating electrical machine 10. The rotating electrical machine 10 is a three-phase synchronous type, and a rotor shaft 14 that is an output shaft is supported on a motor case 12, a rotor 20 that is a rotor is fixed to the rotor shaft 14, and a stator is provided on the outer peripheral side of the rotor 20. A certain stator 30 is arranged.

  The rotor 20 is a rotor fixed to the rotor shaft 14 as described above, and includes a rotor core 22 formed by stacking electromagnetic steel plates, and a plurality of permanent magnets 24 arranged in an embedded manner in the rotor core 22. Is done. The permanent magnet 24 may be arranged so as to face the stator 30 directly without being embedded in the rotor core 22.

  The stator 30 has a function of applying a rotating magnetic field to the rotor 20, and is a stator that applies rotational energy to the rotor 20 by an electromagnetic cooperative action between the rotating magnetic field and the permanent magnet 24 of the rotor 20. Stator 30 includes a stator core 32 formed by laminating electromagnetic steel plates and a winding portion wound around the stator core.

  The stator core 32 is an annular member, and a plurality of protruding portions called teeth are arranged on the inner peripheral side along the circumferential direction. The winding portion inserts a coil winding into a space called a slot between adjacent teeth of the stator core 32, and winds the coil winding around the teeth in a predetermined manner, and when the winding is finished. And a coil end portion drawn out of the stator core 32 from the slot. In FIG. 1, since the slot winding is hidden inside the stator core 32, only the coil end portion 34 is shown.

  FIG. 2 is a perspective view of the stator 30 shown in FIG. Here, a plurality of teeth 36 are shown on the inner peripheral side of the stator core 32, a slot 38 that is a gap space between adjacent teeth 36 is shown slightly, and the slots 38 are pulled out to both sides in the axial direction of the stator core 32. The manner in which the coil winding forms the coil end 34 is shown.

  FIG. 3 is a diagram illustrating a state where the portion A in FIG. 2 is viewed from the inner diameter side, and FIG. 4 is a diagram illustrating a cross-sectional state along the line SS in FIG. In FIG. 3, the stator core 32 is shown as a tooth 36, and the slot 38 is shown showing an insulating sheet 40 disposed therein. As shown in FIG. 4, the portion of the coil winding 50 in the insulating sheet corresponds to the slot winding 33. FIG. 3 shows a state in which the two coil windings 50 overlap each other in the upper and lower coil end portions 34 of the stator core 32.

  In the slot 38 of the stator core 32, as shown in FIG. 4, one coil winding 50 is sequentially stacked and inserted. That is, the three-phase coil windings 50 of the rotating electrical machine 10 are adjacently stacked. One coil winding 50 has a conductor portion 52 made of a copper wire or the like, and an insulating film portion 54 made of a thermoplastic resin such as polyamide (PA) on the conductor portion 52.

  The material of the conductor portion 52 may be a good conductor metal other than copper. A material other than polyamide can be used for the material of the insulating coating 54. For example, polypropylene (PP), polytetrafluoroethylene (PTFE), polyamideimide (PAI), polyester (PE), polyimide (PI), polyacetal (POM), or the like can be used. As a method of forming the insulating film portion 54 on the conductor portion 52, an insulating varnish which is a mixture of a thermoplastic resin and a solvent is applied on the conductor portion 52 and baked in an appropriate baking furnace. Can do.

  The conductor portion 52 has a rectangular basic cross-sectional shape, and has a cross-sectional shape in which each side of the rectangular shape is curved outward. The shape in which each side is curved outward is set in consideration of the fact that when the insulating film portion 54 is formed, the thickness of the insulating varnish becomes thicker at the corner and thinner at the side.

  Setting of the curved shape of the cross section of the conductor portion 52 will be described with reference to FIGS. FIG. 5 is a cross-sectional view of a coil winding 50 in which an insulating coating 54 is formed on a conductor 52 having a rectangular basic cross-sectional shape and each side curved outward. FIG. 6 is a view for comparison, and is a cross-sectional view of a coil winding 60 in which an insulating film portion 64 is formed on a conductor portion 62 having a rectangular cross-sectional shape.

  As described above, in the method of applying the insulating varnish containing the thermoplastic resin to the conductor portions 52 and 62 to form the insulating coating portions 54 and 64, the conductor portion 52 is formed by the surface tension of the insulating varnish that is a fluid. , 62 is thickened, and the film thickness is thinned at the side portions between the adjacent corners. Therefore, in the case of FIG. 6 in which the conductor portion 62 has a rectangular cross-sectional shape, the overall cross-sectional view of the coil winding 60 is not a rectangular shape, but has a corner portion that protrudes and is recessed at each side accordingly. 66, 68 are possible.

  When other coil windings are stacked on the coil winding 60, the protruding corners come into contact with each other. In FIG. 6, the envelope connecting the outside of the protruding corner portion is indicated by a broken line, and the rectangular shape surrounded by the envelope corresponds to the occupied sectional area of the coil winding 60. In FIG. 6, the portions of the depressions 66 and 68 become gaps between the envelope shapes, and the space factor becomes a low value corresponding to the depressions 66 and 68.

In FIG. 5, the fluidity and surface tension of the insulating varnish described with reference to FIG. 6 are considered, and the basic cross-sectional shape of the conductor 52 is rectangular, and each side has a shape that curves outward. Specifically, given the curvature of radius of curvature R ₁ in the long side of the rectangular shape, given the curvature of radius of curvature R ₂ in the short side. The curvature radii R ₁ and R ₂ are such that the surface tension of the insulating varnish is such that the thickness of the insulating coating 54 at the corners of the conductor 52 is the same as the thickness of the insulating coating at each side. Is set in consideration of

Thus, by setting the magnitudes of the curvature radii R ₁ and R ₂ , the depression 56, between the rectangular shape surrounded by the outer envelope in the cross section of the coil winding 50 and the outer shape of the coil winding 50, The gap due to 58 can be hardly generated. In other words, when another coil winding is stacked on the coil winding 60, the central portion of each side surface of the conductor portion and the central portion of each side surface of the adjacent conductor portion facing this between the adjacent conductor portions. The sizes of the curvature radii R ₁ and R ₂ are set so that the distance L between which the insulating film portion is sandwiched is the shortest. Thereby, for example, when the coil winding 50 is stacked and inserted into the slot 38, the space factor is remarkably improved as compared with the coil winding 60 described in FIG.

  In the above description, the basic cross-sectional shape of the conductor portion 52 has been described as a rectangle. However, even when the basic cross-sectional shape is a polygon, a similar film thickness difference occurs between the corner and each side. The cross-sectional shape is preferably curved outward. In the above description, the insulating varnish is used to form the insulating film portion. However, even in other forming methods, the thermoplastic resin or the mixture containing the fluid has fluidity. Similarly, the cross-sectional shape can be obtained by bending each side outward.

  The conducting wire with an insulating film according to the present invention can be used for a stator winding of a rotating electrical machine.

  DESCRIPTION OF SYMBOLS 10 Rotating electrical machine, 12 Motor case, 14 Rotor shaft, 20 Rotor, 22 Rotor core, 24 Permanent magnet, 30 Stator, 32 Stator core, 33 Slot winding, 34 Coil end part, 36 teeth, 38 slot, 40 Insulating sheet, 50, 60 Coil winding, 52 conductor part, 52, 62 conductor part, 54, 64 Insulating film part, 56, 58 Indentation.

Claims (5)

A conductive wire with an insulating film for coil winding, which is sequentially wound around a winding frame,
A conductor portion having a polygonal basic cross-sectional shape;
An insulating film formed on a conductor and made of a thermoplastic resin; and
Have
Conductor part is a distance between adjacent conductor parts when wound between the center part of each side surface of the conductor part and the insulating film part between the center part of each side surface of the adjacent conductor part facing this. A conductor with an insulating film, characterized by having a cross-sectional shape in which each side of the basic cross-sectional shape is curved so that is shortest. In the lead with an insulating film according to claim 1,
Insulating film part is formed with thermoplastic resin, Conductive wire with insulating film characterized by the above-mentioned. In the conductor with an insulating film according to claim 2,
The magnitude of the curvature of each side of the conductor part is set in advance based on the difference between the thickness of the insulating film part at the polygonal corner of the conductor part and the thickness of the insulating film part at each side. Conductive wire with insulating film characterized by the above. In the lead with an insulating film according to claim 3,
The conductor has a square or rectangular basic cross-sectional shape. A rotor that is a rotor attached to the rotor shaft;
A stator that is provided on the outer peripheral side of the rotor and that is a stator including a conductor with an insulating film for coil winding;
With
Conductive wire with insulating film is
A conductor portion having a polygonal basic cross-sectional shape;
An insulating film formed on a conductor and made of a thermoplastic resin; and
Have
Conductor part is a distance between adjacent conductor parts when wound between the center part of each side surface of the conductor part and the insulating film part between the center part of each side surface of the adjacent conductor part facing this. A rotating electrical machine characterized by having a cross-sectional shape in which each side of the basic cross-sectional shape is curved so that is shortest.

Images