JP2000014067A - Coil structure and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the heat conductivity between a coil and a core, in coil structure where an insulating sheet is interposed between the coil and the core. SOLUTION: In the coil structure of a motor or the like where a plurality of slots are made in the core 1 consisting of a magnetic substance, an insulating sheet 3 which is provided with a plurality of openings (small holes) through the sheet face is provided along the inner face of the slot 2. Then, the gap part between the coil 6 wound through the slot 2 and the inner face of the slot 2 is impregnated with a binder 8, and a heat conductive path is secured to the utmost by the binder 8 filled between the coil 6 and the core 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil structure in which an insulating sheet is interposed at a portion where a coil is wound, such as a stator of an electric motor, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In a coil structure in which a coil is wound around a core such as a stator of an electric motor, heat is generated due to copper loss when an electric current is applied to the coil. This is one factor that lowers the performance limit.

[0003] In order to prevent the insulation film from being damaged due to contact between the copper wires due to vibration or the like, there is a type in which a coil is impregnated with a fixing material such as varnish and fixed, and in this case, the fixing material causes heat conduction between the copper wires. Although it is somewhat advantageous in terms of heat dissipation because it mediates heat transfer, as described above, usually only the impregnating material is impregnated for the purpose of fixing the coil, so there is a gap between the coil and the core that hinders heat transfer. Many remain, and the heat dissipation is not always good.

In addition, an insulating sheet made of paper or other insulating material is attached between the core and the coil in order to improve the insulating ability and prevent the insulation film on the surface of the copper wire from being broken when the coil is installed. However, in such a coil structure, the insulating sheet hinders heat transfer from the coil to the core, and even when the coil is impregnated with a fixing material, many gaps are generated in the gap between the insulating sheet and the core. Therefore, the heat radiation is further reduced.

[0005] Japanese Patent Application Laid-Open No. 7-274453 discloses a method in which an insulating film having a large number of small holes is used in forming an insulating layer on the surface of a copper wire to improve the impregnation of the resin. However, this is for the purpose of increasing the strength of the insulating layer, and is not expected to have the effect of improving the heat dissipation of the coil.

The present invention has been made in view of such a problem. In a coil structure in which an insulating sheet is interposed between a coil and a core, the heat transfer between the coil and the core has been improved. A coil structure and a method for manufacturing the same are provided.

[0007]

According to the first aspect of the present invention, an insulating sheet having a plurality of openings formed through a sheet surface is interposed between a core and a coil wound around the core. Further, a coil structure is provided in which a gap between the coil and the core provided with the insulating sheet is impregnated with a fixing material such as varnish.

According to a second aspect of the present invention, there is provided a coil structure such as an electric motor having a plurality of slots formed in a core made of a magnetic material as a coil winding portion, wherein the insulating sheet has a plurality of openings formed through a sheet surface. It is provided along the inner surface of the slot, and a gap between the coil wound around the slot and the inner surface of the slot is impregnated with a fixing material.

According to a third aspect of the present invention, as the insulating sheet according to the second aspect of the present invention, a folded portion is formed outward from an opening end of the slot, and an opening is formed only in a portion facing the inner surface of the slot. The provisions shall be applied.

According to a fourth aspect of the present invention, the opening of the insulating sheet of each of the above inventions is formed in a honeycomb shape having a large number of hexagonal holes.

According to a fifth aspect of the present invention, an insulating sheet having a plurality of openings penetrating the sheet surface is interposed in the coil winding portion of the core, and then the coil is wound, and the core is inclined. This is a method for manufacturing a coil in which a fixing material is dropped from above toward a gap between the coil winding portion and the coil to impregnate the fixing material between the core and the coil.

[0012]

According to each of the above-mentioned inventions, since the fixing material can be sufficiently spread to the gap between the coil and the core through the opening provided in the insulating sheet, a gap is generated between the coil and the core. Thus, the heat transfer path by the fixing material can be maximized. For this reason, even in the coil structure in which the insulating property is enhanced by the insulating sheet, the heat radiation from the coil and the core can be enhanced and the temperature rise can be suppressed.

According to the second aspect of the present invention, heat can be efficiently transferred from the coil provided in the slot of the stator core to the core side for the same reason as described above, so that the temperature rise of the stator coil can be suppressed. As a result, the performance limit of an electric motor or the like can be increased.

According to the third aspect of the present invention, the folded portion of the insulating sheet facilitates temporary fixing when the sheet is mounted in the slot, and the coil is rubbed against the opening edge of the slot to damage the insulating film. Can be prevented. In addition, since the opening of the insulating sheet is provided only at a portion facing the inner surface of the slot, avoiding the opening edge, there is no possibility that the coil will directly contact the opening edge through the opening, and damage to the insulating film will not occur. Prevention can be reliably performed.

According to the fourth aspect of the present invention, since the openings are formed in a honeycomb shape, a large number of openings are provided to secure a large total opening area while securing sufficient strength and rigidity in the insulating sheet. Deformation and breakage during assembly to the core can be prevented.

According to the fifth aspect of the present invention, the fixing material is impregnated by dropping the fixing material toward the gap between the coil winding portion of the core and the coil while the core is inclined. By impregnating the gap evenly with the fixing material, a coil structure having high heat dissipation can be realized.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a stator coil of a motor will be described below with reference to the drawings.

1 to 3, reference numeral 1 denotes a stator core, which is formed by laminating a number of annularly punched iron plates. The stator core 1 has a substantially elliptical slot 2 that is open at one end on the inner peripheral side and penetrates the core in the axial direction.
Are radially formed in large numbers.

Reference numeral 3 denotes an insulating sheet mounted so as to fit in the slot 2. The insulating sheet 3 is made of an electrically insulating sheet material such as paper or resin, and has a number of small holes 4 formed as openings passing through the sheet surface. The insulating sheet 3 can be formed, for example, by using an existing roll-shaped sheet as shown in FIG.

The insulating sheet 3 provided with the small holes 4 is formed such that when it is mounted on the stator core 1, the outer folded portions 5 are formed on both edges as portions for covering the opening edges of the slots 2. It is installed in the slot 2 in a state of being bent in a substantially U-shape according to. In this case, as shown in FIG. 5, the small holes 4 are formed only on the portion facing the inner surface of the slot inside so as not to cover the opening edge of the slot 2.

Reference numeral 6 denotes a coil made of an enameled copper wire, which is wound around the stator core 1 so as to pass through the inside of the slot 2 on which the insulating sheet 3 is mounted as described above. Reference numeral 7 denotes a wedge made of an insulating material for urging the coil 6 wound around the stator core 1 outward in the slot 2 to securely fix the coil.

Reference numeral 8 denotes a fixing material filled between the coil 6 and the slot 2. As the fixing material 8, a varnish or other resin material which has fluidity and electrical insulation and is solidified by drying or heat treatment is used.

To fill the fixing material 8, the coil 6 is wound after the insulating sheet 3 is attached to the slot 2 of the stator core 1 as described above, and then the stator core 1 is held at an angle as shown in FIG. Slot 2 and coil 6
The flowable fixing material is dripped with the nozzle 9 facing the upper part of the gap between the nozzle and the nozzle. While dripping the fixing material, the stator core 1
May be appropriately rotated or the angle may be changed. When the fixing material is poured in this way, the fixing material easily penetrates into the front and back surfaces of the insulating sheet 3 through the many small holes 4, so that the fixing between the coil 6 and the inner surface of the slot 2 is evenly and sufficiently performed. It is possible to prevent the material from spreading and voids that hinder heat conduction.

According to the above-described stator coil structure, the heat transfer path by the fixing material 8 can be maximized. Therefore, even in the configuration in which the insulating property is improved by the insulating sheet 3, the heat radiation from the coil 6 and the stator core 1 is improved. And the temperature rise can be suppressed, so that the performance limit of the electric motor and the like can be increased accordingly.

Further, since the insulating sheet 3 has no opening at the portion corresponding to the opening edge of the slot 2, the coil 6 is directly rubbed against the opening edge, and the insulating coating on the copper wire surface is peeled off by vibration. No inconvenience is caused.

It is to be noted that a large number of hexagonal small holes can be arranged in a honeycomb shape as the opening (see FIG. 4). According to this, a large number of small holes 4 are provided to ensure the maximum total opening area. While securing sufficient strength and rigidity to the insulating sheet 3, it is possible to prevent deformation and breakage during assembly to the stator core 1. In addition, the shape of the opening is not limited to the above-described one, and for example, a configuration in which a number of long holes 10 are formed in an oblique direction as shown in FIG.

[Brief description of the drawings]

FIG. 1 is a plan sectional view of a main part of a stator coil according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view showing a state in which an insulating sheet is attached to a stator core of the embodiment.

FIG. 4 is an explanatory view showing a processing example of an insulating sheet.

FIG. 5 is an explanatory view showing an opening area of a small hole (opening) of the insulating sheet. l

FIG. 6 is an explanatory view showing a method for filling a fixing material.

FIG. 7 is a perspective view showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stator core 2 Slot 3 Insulating sheet 4 Small hole (opening) 5 Folding part 6 Coil 7 Wedge 8 Fixing material 9 Dropping nozzle of fixing material

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshio Kikuchi 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Inside Nissan Motor Co., Ltd. (72) Inventor Ryuichi Wellguchi 2 Takaracho, Kanagawa-ku, Yokohama City, Kanagawa Nissan Motor (72) Inventor Yutaro Kaneko F-term in Nissan Motor Co., Ltd. 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa 5F604 AA03 BB01 BB14 CC01 CC05 DB02 DB26

Claims (5)

[Claims] An insulating sheet having a plurality of openings formed through a sheet surface is interposed between a core and a coil wound around the core, and the core and the coil having the insulating sheet interposed therebetween. A coil structure in which a fixing material is impregnated in a gap between the coil and the fixing member. 2. A coil structure, such as an electric motor, in which a plurality of slots are formed in a core made of a magnetic material as a coil winding portion, an insulating sheet having a plurality of openings penetrating a sheet surface is provided on an inner surface of the slot. And a gap between the coil wound around the slot and the inner surface of the slot is impregnated with a fixing material. 3. The insulating sheet according to claim 2, wherein a folded portion is formed outward from an opening end of the slot, and an opening is provided only in a portion facing the inner surface of the slot. Coil structure. 4. The coil structure according to claim 1, wherein the opening of the insulating sheet is formed in a honeycomb shape having a large number of hexagonal holes. 5. An insulating sheet having a plurality of openings penetrating a sheet surface is interposed in a coil winding portion of a core, and then the coil is wound, and the coil is wound in a state where the core is inclined. A method for manufacturing a coil, wherein a fixing material is dropped from above toward a gap between the coil and the core to impregnate the fixing material with the coil.