JP2004096907A - Stator of motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stator of motor provided with coils with enhanced insulation between layers of flat wires wound in layers. <P>SOLUTION: The stator comprises an annular stator core provided with a plurality of salient poles, and flat wire coils (120) formed by tightly winding flat wires (121) covered with insulating coatings in layers on the individual salient poles with an insulator (130) between. The flat wire (121) is so formed that its cross-sectional shape has a pointed portion (121c) extended in the direction of the axis of the flat wire coil (120) winding. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a stator for an electric motor having a rectangular wire coil formed by winding a rectangular wire having insulation coating.
[0002]
[Prior art]
As described in Japanese Patent Application Laid-Open No. H5-243036, an electric motor using a coil formed by laminating and winding a flat wire is known as a stator (also referred to as a stator). The rectangular wire is coated with an insulating material such as polyester or polyesterimide.
[0003]
[Problems to be solved by the invention]
However, the stator of the electric motor has the following problems.
[0004]
The corner portion between the long side and the short side in the cross-sectional shape of the rectangular wire has a thin coating of the insulating material and is a thin portion of the insulating film. When the rectangular wires are laminated and wound, if the insulating film thin portions of the rectangular wires adjacent to each other in the laminating direction are adjacent to each other, a short circuit easily occurs between the layers of the rectangular wires.
[0005]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a stator of an electric motor including a coil having an improved insulating property between layers of a laminated and wound rectangular wire.
[0006]
[Means for Solving the Problems]
The present invention for solving the above-mentioned problems and achieving the object has an annular stator core having a plurality of salient poles, and an insulated-coated flat wire is densely wound around each salient pole via an insulator. And a cross-sectional shape of the flat wire having a pointed end extending along the winding axis direction of the flat wire coil.
[0007]
【The invention's effect】
According to the present invention, the cross-sectional shape of the flat wire wound around the salient pole of the stator core is a shape having a pointed end extending along the winding axis direction of the flat wire coil. In addition, the distance between the corners of the rectangular wires adjacent to each other in the laminating direction is increased, so that it is possible to provide a motor stator including a coil having improved insulation between layers of the laminated and wound rectangular wires.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a stator for an electric motor according to the present invention will be described below in detail with reference to the accompanying drawings in a first embodiment and a second embodiment. Layer thicknesses in the drawings used in this description are exaggerated for clarity.
[0009]
(1st Embodiment)
The stator of the electric motor according to the present embodiment includes an annular stator core having a plurality of salient poles, and a rectangular wire coil in which an insulated rectangular wire is densely stacked and wound around each salient pole via an insulator. The cross section of the rectangular wire has a pointed end extending along the winding axis direction of the rectangular coil. Hereinafter, the present embodiment will be described with reference to the drawings.
[0010]
FIG. 1 is a cross-sectional configuration diagram of a motor using a stator according to the present embodiment. The electric motor has a rotor 200 and a stator 100. The rotor 200 and the stator 100 are supported by the cover 300 and the case 500.
[0011]
The rotor 200 has a rotor core 210 on which electromagnetic steel sheets are laminated. The shaft 220 is press-fitted to the rotor core 210, and the permanent magnet 230 is inserted therein. The permanent magnet 230 is enclosed by an end plate 240. End plate 240 is welded to shaft 220. The rotor 200 is rotatably supported by a bearing 310 incorporated in the cover 300.
[0012]
The stator 100 will be described with reference to FIGS. FIG. 2 is an external perspective view of the stator 100 according to the present embodiment. FIG. 3 is a diagram illustrating a part of a cross section (cross-section AA ′) of the stator 100 according to the present embodiment when cut along a plane perpendicular to the axis X of the stator 100. Stator 100 has an annular stator core 110 having a plurality of salient poles. In the present embodiment, a stator core 110 obtained by assembling annularly divided cores 111 divided by one pole is used. The split core 111 is formed by laminating electromagnetic steel sheets punched into a predetermined shape and joining them by caulking, laser welding, or the like, and has salient poles 111a. On the salient poles 111a of each of the divided cores 111, a rectangular wire 121, which is a strip-shaped conductor covered with an insulating coating, is densely laminated and wound via an insulator 130 to form a rectangular wire coil 120. In this specification, "the flat wire is wound by lamination" means that the flat wire is wound so as not to shift in the winding axis Y direction as shown in FIG. Here, from the viewpoint of space efficiency, it is preferable that the flat wire 121 is laminated and wound such that the end faces in the width direction are flush.
[0013]
The rectangular wire 121 is formed by extruding a conductive material such as aluminum, copper or the like into a desired shape described later, and has dimensions of a width of 7.5 mm and a thickness of 0.6 mm. However, the material, manufacturing method, and dimensions of the flat wire 121 are not limited to these.
[0014]
Since the rectangular wire 121 is wound by lamination, the rectangular wire coil 120 has a laminated structure. In the present embodiment, the rectangular wire coil 120 includes a first-row coil 120a and a second-row coil 120b arranged along the winding axis Y direction. The first-row coil 120a and the second-row coil 120b are provided on the stator outer circumference 100a side and the stator inner circumference 100b side of the salient poles 111a, respectively. The first-row coil 120a and the second-row coil 120b are electrically connected to each other. The first-row coil 120a and the second-row coil 120b may be formed by one rectangular wire, or may be formed by two rectangular wires. However, when formed by two rectangular wires, the first-row coil 120a and the second-row coil 120b need to be electrically connected by appropriate means.
[0015]
A gap 140 is provided between the rows of the first-row coil 120a and the second-row coil 120b. The gap 140 is provided as a space in which a refrigerant for removing heat generated from the rectangular wire coil 120 and the split core 111 flows. Spacers 150 are sandwiched between adjacent split cores 111. Since the spacer 150 eliminates a gap between the adjacent divided cores 111, the vibration of the rectangular wire coil 120 is suppressed, and the refrigerant actively flows into the gap 140. An under plate 160 is provided on the stator inner circumference 100b side of the second row of coils 120b, and a shield plate 170 made of insulating resin is molded between the under plate 160 and the stator inner circumference 100b. The shield plate 170 has an annular shape at both ends in the direction of the axis X of the stator 100.
[0016]
As shown in FIG. 1, stator 100 is press-fitted to case 500. The shield plate 170 of the stator 100 is inserted into contact with the groove 321 of the seal ring 320 incorporated in the cover 300. The cover 300 and the case 500 are joined by welding or the like.
[0017]
The cover 300 is provided with an inlet 330 and an outlet 340 for the refrigerant. The refrigerant is supplied from the inflow port 330 and passes through the gap 140 between the first-row coil 120a and the second-row coil 120b from the inflow-side refrigerant reservoir 410 formed by the cover 300, the case 500, and the shield plate 170. Is discharged from the discharge port 340 via the refrigerant reservoir chamber 420 on the discharge port side. By the flow of the refrigerant, heat generated from the stator 100 can be removed.
[0018]
Next, the cross-sectional shape of the flat wire 121 used for the stator 100 according to the present embodiment will be described with reference to the drawings while comparing with the flat wire of the comparative example. FIG. 5 is an enlarged view of the vicinity of the gap 140 (portion B in FIG. 3), that is, a cross-sectional view of the rectangular wire lamination of the first-row coil 120a and the second-row coil 120b near the gap 140. FIG. 6 is a cross-sectional view of a rectangular wire stack of the first-row coil 120a ′ and the second-row coil 120b ′ near the gap 140 ′ when the rectangular wire 121 ′ of the comparative example is used instead of the rectangular wire 121 of the present embodiment. It is. In addition, in this specification, the “straight wire lamination cross section” means a cross section of a flat wire coil when cut along a plane perpendicular to the longitudinal direction of the flat wire.
[0019]
The rectangular wires 121 and 121 'are covered with insulating films 122 and 122' of about 0.03 to 0.04 mm in thickness such as polyester or polyesterimide. However, as shown in FIG. 6, since the cross-sectional shape of the rectangular wire 121 'of the comparative example is substantially rectangular, the insulating film is formed at a right-angled corner between the long side 121a' and the short side 121b 'in the cross-sectional shape. 122 'becomes thinner and becomes an insulating film thin portion 123'. Furthermore, the insulating film thin portions 123 'are adjacent to each other between the rectangular wires 121' adjacent to each other in the rectangular wire laminating direction (the direction of the arrow Z '), and the shortest distance L' between the insulating film thin portions 123 'is very small. small. In this comparative example, the shortest distance L 'is about 0.04 to 0.06 mm. Therefore, when the flat wire 121 'of the comparative example is used, there is a problem that a short circuit easily occurs between the layers around which the flat wire 121' is wound. In order to solve this problem, generally, after winding the flat wire 121 ′, a varnish treatment such as polyester or epoxy is performed, and the entire flat wire coil 120 ′ is covered with a varnish 124 ′ to improve insulation. Have improved. However, this varnish treatment requires a varnish dropping device, a drying device, and the like, and thus has a problem of increasing costs.
[0020]
As shown in FIG. 5, the cross-sectional shape of the flat wire 121 of the present invention is a shape having sharp ends 121c extending along the winding axis Y direction of the flat wire coil 120, and in the present embodiment, the sharp ends 121c at both ends. And a substantially trapezoidal shape. This is a feature different from the flat wire 121 'of the comparative example. In the present embodiment, the angle θ of the tip 121c is 45 ° and the radius of curvature R is 0.1 mm, but the angle θ and the radius of curvature R are not limited to these. The tip 121c has a thin insulating film 122 and a thin insulating film portion 123. However, since the pointed end 121c protrudes along the winding axis Y direction, the insulating film thin portions 123 do not adjoin each other between the layers of the rectangular wires 121 adjacent in the rectangular wire laminating direction (the direction of the arrow Z). That is, the shortest distance L between the insulating film thin portions 123 of the flat wires 121 adjacent in the flat wire laminating direction is much larger than the shortest distance L 'of the comparative example.
[0021]
As described above, according to the rectangular wire 121 of the present embodiment, since the insulating film thin portions 123 between the rectangular wires 121 adjacent to each other in the rectangular wire laminating direction (the direction of the arrow Z) in the rectangular wire coil 120 are not adjacent to each other, The insulation between the layers of the wound flat wire 121 can be improved. In addition, since the corner 121d which contacts the layer of the flat wire 121 adjacent in the flat wire laminating direction has an obtuse angle (135 ° in the present embodiment), the thickness of the insulating film 122 at the corner 121d is the right angle of the comparative example. In this regard, the insulation between the layers of the flat wire 121 is also improved. From the viewpoint of improving the insulation properties, it is preferable that a corner portion that contacts the layer of the flat wire 121 adjacent in the flat wire laminating direction is 110 to 170 °.
[0022]
In addition, since the insulation between the layers of the laminated and wound rectangular wire 121 is improved, the varnish treatment can be omitted. Thereby, the cost of the stator 100 of the electric motor can be reduced.
[0023]
Further, when the varnish treatment is not required, the heat transfer coefficient on the surface of the rectangular wire coil 120 increases, and the heat radiation performance of the rectangular wire coil 120 when the coolant flows through the gap 140 improves.
[0024]
Further, since the cross-sectional shape of the flat wire 121 has a pointed end 121c extending along the winding axis Y direction of the flat wire coil 120 on the gap 140 side, the contact area between the flat wire coil 120 and the refrigerant increases. At the same time, the flow of the refrigerant in the gap 140 becomes turbulent, and the heat radiation performance of the rectangular coil 120 is improved.
[0025]
Further, since the thin insulating portion 123 of the flat wire 121 is formed at the pointed end 121c, the heat radiation performance of the flat wire coil 120 is improved. Here, in order to obtain higher heat dissipation performance, it is preferable that the radius of curvature R of the tip 121c is 0.3 mm or less.
[0026]
In the present embodiment, the cross-sectional shape of the flat wire 121 is substantially trapezoidal. However, the shape is not limited to this, and any other shape having a pointed end extending along the winding axis Y direction of the flat wire coil 120 may be used. Shape. FIG. 7 is a diagram showing another example of the cross-sectional shape of the flat wire. The cross-sectional shape of this flat wire is a flat, substantially hexagonal shape.
[0027]
Further, in the present embodiment, the flattened wire 121 has sharp ends at both ends in the winding axis Y direction. However, if at least one end has a sharp end, the insulating property can be improved. it can. However, from the viewpoint of improving the heat radiation performance, it is preferable to have a point at least on the gap 140 side, and from the viewpoint of improving the insulation properties, it is more preferable to have the point at both ends.
[0028]
Further, in the present embodiment, the rectangular wire coil 120 is composed of two rows of rectangular wire coils. However, the present invention is not limited to this, and it may be one row or three or more rows.
[0029]
(Second embodiment)
The stator of the electric motor according to the present embodiment is almost the same as the stator of the electric motor according to the first embodiment, but in a rectangular wire laminated cross section of two rows of rectangular wire coils,
The flat wire of the two rows of flat wire coils is laminated and wound such that the positions of the sharp ends in the flat wire lamination direction are alternately shifted. Hereinafter, the present embodiment will be described with reference to the drawings, but description of parts common to the first embodiment will be omitted.
[0030]
FIG. 8 is a cross-sectional view of a flat wire lamination of a first-row coil and a second-row coil of the stator of the electric motor according to the present embodiment. As shown in FIG. 8, the thickness D1 of the insulator 630 where the first-row coil 610 is wound is larger than the thickness D2 of the insulator 630 where the second-row coil 620 is wound. That is, the winding start position of one first-row coil 610 of the two-row rectangular wire coils 610, 620 is offset in the rectangular wire laminating direction (arrow Z direction). In the present embodiment, the thickness difference (D1-D2) of the insulator 630, that is, the offset amount ΔD of the winding start position is equal to the thickness E (0.6 mm) of the insulated rectangular wires 611 and 621. The amount is about half (0.3 mm). By offsetting the winding start position of the flat wire coil in this way, the flat wire lamination of the sharp end 611a of the flat wire 611 of the first row coil 610 and the sharp end 621a of the flat wire 621 of the second row coil 620 is performed. The flat wires 611 and 621 of the two rows of flat wire coils 610 and 620 can be wound so that the positions in the directions (arrow Z directions) are alternately shifted.
[0031]
As described above, according to the present embodiment, in the rectangular wire laminated cross section of the two rectangular wire coils 610 and 620, the rectangular wires 611 and 621 of the two rectangular wire coils 610 and 620 are respectively formed with the sharp ends 611a and 621a. Are laminated and wound so that the positions in the rectangular wire laminating direction (arrow Z direction) are alternately shifted, so that the insulating film thin portion 612 of the first-row coil 610 and the insulating film thin portion 622 of the second-row coil 620 Can be increased, and the insulation between the two rows of rectangular wire coils 610 and 620 can be improved. In the first embodiment (when the winding start position is not offset), the shortest distance M between the insulating coating thin portion 123 of the first-row coil 120a and the insulating coating thin portion 123 of the second-row coil 120b is 0.25 mm. is there. In contrast, in the present embodiment, the shortest distance M between the thin insulating film portion 612 of the first-row coil 610 and the thin insulating film portion 622 of the second-row coil 620 is 0.35 mm.
[0032]
In the present embodiment, the offset amount ΔD of the winding start position is set to an amount corresponding to approximately half the thickness E of the insulated rectangular wires 611 and 621. However, the present invention is not limited to this. Other offset amounts may be used as long as the positions of the sharp ends 611a and 621a of the rectangular wire coils 610 and 620 in the row are alternately shifted in the rectangular wire laminating direction (the direction of the arrow Z). Here, from the viewpoint of improving the insulation properties, the amount of offset is preferably set to an amount that maximizes the shortest distance M between the insulating film thin portions 612 and 622 of the two rows of rectangular wire coils 610 and 620.
[0033]
Further, in the present embodiment, the winding start position of one of the two rectangular wire coils is offset in the rectangular wire laminating direction. However, the present invention is not limited to this. As long as the positions of the tips of the rectangular wire coils in the rectangular wire lamination direction can be alternately shifted, other configurations can be adopted. FIG. 9 is a diagram showing another configuration example for alternately shifting the positions of the tips of two rows of rectangular wire coils in the rectangular wire laminating direction. In this configuration example, by making the cross-sectional shape of the rectangular wire different between the first-row coil 710 and the second-row coil 720, the sharp ends 711a, 721a of the two-row rectangular wires 710, 720 with the rectangular wires 711, 721 are formed. Are alternately shifted in the direction of lamination of the rectangular wire (direction of arrow Z).
[Brief description of the drawings]
FIG. 1 is a sectional configuration diagram of an electric motor using a stator of the electric motor according to a first embodiment.
FIG. 2 is an external perspective view of a stator according to the embodiment.
FIG. 3 is a diagram showing a part of a cross section (cross section AA ′) of the stator according to the embodiment.
FIG. 4 is a view showing a laminated rectangular wire.
FIG. 5 is a cross-sectional view of a rectangular wire stack of the rectangular wire coil according to the present embodiment.
FIG. 6 is a cross-sectional view of a rectangular wire stack of a rectangular wire coil when the rectangular wire of the comparative example is used.
FIG. 7 is a diagram showing another example of a cross-sectional shape of a rectangular wire.
FIG. 8 is a cross-sectional view of a rectangular wire stack of a rectangular wire coil according to a second embodiment.
FIG. 9 is a diagram showing another configuration example for alternately shifting the positions of the tips of the two rows of rectangular wire coils in the rectangular wire laminating direction.
[Explanation of symbols]
100 stator 100a stator outer circumference 100b stator inner circumference 110 stator core 111 split core 111a salient pole 120 rectangular wire coil 120a first-row coil 120b second-row coil 121 flat wire 121c pointed tip 122 Insulating film 123 ... Insulating film thin portion 130 ... Insulator 140 ... Gap 150 ... Spacer 160 ... Under plate 170 ... Shield plate 200 ... Rotor 210 ... Rotor core 220 ... Shaft 230 ... Permanent magnet 240 ... End plate 300 ... Cover 310 ... Bearing 320 ... Seal ring 330 Inflow port 340 Discharge ports 410 and 420 Refrigerant chamber 500 Case

Claims (7)

An annular stator core having a plurality of salient poles;
A rectangular wire insulated and covered with a rectangular wire densely wound around each salient pole via an insulator;
A stator for an electric motor, wherein the cross section of the rectangular wire has a pointed end extending along the winding axis direction of the rectangular coil. The stator of an electric motor according to claim 1, wherein the cross-sectional shape of the rectangular wire is substantially trapezoidal. The flat wire coil is composed of at least two rows of flat wire coils arranged with a gap along the winding axis direction,
A coolant is flowed in the gap,
2. The cross-sectional shape of the rectangular wire of the two rows of rectangular wire coils is a shape having a pointed end extending along the winding axis direction of the rectangular wire coil on the gap side. 3. 3. The stator of the electric motor according to claim 1. In the rectangular wire laminated cross section of the two rows of rectangular wire coils, the rectangular wires of the two rows of rectangular wire coils are laminated and wound such that the positions of the respective tips in the rectangular wire lamination direction are alternately shifted. The stator of an electric motor according to claim 3, wherein: The stator according to claim 4, wherein a winding start position of one of the two rectangular wire coils is offset in a rectangular wire laminating direction. The motor stator according to claim 1, wherein the stator core is formed of a split core divided by one pole, and the flat wire is wound around the split core in a stacked manner. The stator for an electric motor according to claim 1, wherein a radius of curvature of the tip is 0.3 mm or less.

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