JPH0775274A - Layer insulation sheet of laminated core of electric apparatus and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain an alternative layer insulation sheet which provides less risk for contaminating working environment and also provides various performances required as the layer insulation sheet. CONSTITUTION:A composite insulation sheet is provided, for insulating iron core plate segments, between layers of iron core plate segments of an electric apparatus iron core, where the iron core segments of the predetermined shape are stacked. layer insulation sheet 11 is composed of the composite insulation sheet which is formed by bonding a ceramic fiber paper 12 including resin binder and a polyester film 13 for electrical use through a bonding agent layer 14. Any one surface is provided with a bonding layer 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interlayer insulation sheet which is laminated between layers of core plate segments of a stacked core such as a stator core of a large rotating machine to prevent mutual contact of the core plate segments and reduce iron loss. And a processing method for punching the interlayer insulating sheet into a shape and size adapted to the core plate segment.

[0002]

2. Description of the Related Art FIG. 4 is a perspective sectional view showing a main part of a stator core of a large-sized rotating machine. The stator core is formed in a tubular shape and has a slot 5 for accommodating a stator winding on its inner peripheral surface. 10
Is an iron core plate segment 1 made of a silicon steel plate punched into a fan shape in which the stator core is divided into a plurality of pieces in the circumferential direction,
Spacers 3 that are stacked at different positions in the circumferential direction to form a plurality of layers of core blocks 2 and hold cooling ducts between the layers.
It is configured such that a plurality of layers are stacked in a stator frame (not shown) by interposing, and supported by the stator frame in a state in which a tightening load is applied axially. Positioning holes 4 are formed in the iron core plate segment 1 at a plurality of positions, and the fan-shaped iron core plate segment 1 is formed by the positioning pins penetrating the positioning holes.
By carrying out the iron core stacking work so that the ends of the cores overlap each other, a cylindrical stator core having the slots 5 on the inner peripheral side is formed.

In the stator core thus constructed, magnetic flux is induced by the current flowing through the stator winding, and
Since a potential difference occurs between the iron core plate segments 1, the iron core plate segments with high resistivity are used to reduce eddy current loss, and the iron core plate segments 1 of different potentials contact each other to form a short circuit path. In order to prevent the eddy current loss from being generated by the current passing through the short-circuit path, a method of baking varnish on the surface of the iron core plate segment to prevent electrical contact between the iron core plate segments is known. However, the iron core plate segment 1 is apt to have protrusions such as burrs on the edge of the punched portion,
This causes a problem that the varnish film is damaged when a tightening load is applied to the core block, and a short circuit path is formed between the core plate segments. Further, in order to eliminate such a problem, it is known that an interlayer insulating sheet punched and formed to have the same shape and dimensions as the core plate segment is interposed between the layers of the core plate segment 1 (Jitsuko Sho). 60-1
3259).

FIG. 5 is a sectional view showing an insulating structure of an interlayer insulating sheet of a conventional iron core for electric equipment. An interlayer insulating sheet 6 is an asbestos paper 7 having a thickness of about 0.15 mm impregnated with a resin binder. It consists of a composite sheet with a 5 μm-thick polyester film 8 bonded as a plastic film on the surface, which is punched into the same shape and dimensions as the core plate segment, and the core plate segment 1 and the interlayer insulation sheet during core stacking work. The core blocks 2 are formed by alternately stacking the cores 6 and the cores 6, and a plurality of core blocks are stacked with the spacers 3 interposed therebetween, and a tightening load is applied while being supported by the stator frame. The stator core is assembled.

[0005]

Interlayer insulation sheets alternately laminated with core plate segments on a stator core of a large rotating machine.
Is exposed to the operating temperature of the rotating machine in a state of being tightened with a large surface pressure, and due to the heat cycle associated with repeated running and stopping of the rotating machine, the surface is based on the difference in thermal expansion from the core plate segment. A tensile load is applied in the direction, and at that time, friction with the edge of the punched iron core plate segment and frictional force acting on metal foreign matter such as iron powder adhering to the surface of the iron core plate segment are applied to severe conditions. Exposed. Therefore, the interlayer insulation sheet should maintain a constant compressive deformation rate with respect to the tightening load, and the dimensional change due to moisture absorption should be small. Also, the metal foreign matter stuck in the interlayer insulation sheet due to the tightening load should be enclosed to make it harmless, and the withstand voltage strength should not be reduced. In addition, it has high tensile strength and does not crack or break due to tensile load in the surface direction due to thermal stress or friction with the edges of the core plate segment. Various performances are required. It is known that the conventional interlayer insulating sheet 6 obtained by laminating a plastic film on the above-mentioned resin-impregnated asbestos paper has good punching workability, and has characteristics that are well suited to the required performance.

However, since asbestos has been designated as a carcinogenic harmful substance, the asbestos does not contaminate the work environment during the conventional punching and molding work of the interlayer insulating sheet containing asbestos and the iron core stacking work. There is a growing concern that there is a strong demand for the development of alternative products that do not contain asbestos. An object of the present invention is to obtain an alternative interlayer insulation sheet which has no risk of contaminating the working environment and has various performances required as an interlayer insulation sheet.

[0007]

In order to solve the above problems, according to the present invention, an electric equipment iron core formed by stacking iron core plate segments having a predetermined shape is interposed between the iron core plate segments. A composite insulation sheet for insulating core core plate segments from each other, which is composed of a ceramic fiber paper containing a resin binder and an electrical polyester film bonded together via an adhesive layer. And

It is assumed that the interlayer insulating sheet has a pressure-sensitive adhesive layer on one surface thereof. The roll-shaped or sheet-shaped interlayer insulating sheet is attached to the surface of the roll-shaped or sheet-shaped iron core plate material by the adhesive layer, and then the interlayer insulating sheet is formed. Is to be punched according to the shape and dimensions of the core plate segment that is determined in advance together with the core plate material.

[0009]

In the present invention, the interlayer insulating sheet is a composite insulating sheet of ceramic fiber paper containing a resin binder and a polyester film for electrical use, so that ceramic short fibers or glass short fibers can be formed. Ceramic fiber paper mainly composed of inorganic fibers has less hygroscopicity than asbestos paper, and by containing a resin binder having heat resistance as a binder, the mechanical strength and the asbestos paper impregnated with resin binder and In addition to having moisture resistance, the ceramic short fibers or glass short fibers as the base material are aggregates to show an excellent performance of maintaining the compressive deformation rate, and fine metallic foreign substances stuck into the ceramic fiber paper are separated from the gaps between the inorganic fibers. It is made harmless by encapsulating it in a sheet and prevents damage to the attached polyester film for electrical use. Sheet - with sufficiently satisfy performance characteristics required for bets, alternate interlayer insulation for sheet - can be used in electric appliances stacked iron core and. In addition, since inorganic fibers such as ceramic fibers and glass fibers do not contain active impurities like asbestos, which is a mineral fiber, and therefore do not have a harmful effect on carcinogenicity, the conventional interlayer insulation using asbestos paper. The function to eliminate the environmental pollution problem that has become a problem in the seat can be obtained.

Further, if the interlayer insulating sheet is constructed so as to have an adhesive layer on either surface thereof, the interlayer insulating sheet is pre-attached to the surface of the core plate segment by the adhesive layer and integrated. By doing so, it is possible to obtain a function that saves labor and time for iron core stacking work. Further, if the adhesive layer is provided on the ceramic fiber paper side, both surfaces of the ceramic fiber paper are covered with the polyester film and the adhesive layer to prevent the inorganic fibers from scattering, so that the working environment of the inorganic fibers is The function of preventing fouling is obtained.

Further, an interlayer insulating sheet formed in a roll shape or a sheet shape is attached to the surface of the roll-shaped or sheet-shaped iron core plate material by the adhesive layer, and thereafter, If the processing method is configured so that the interlayer insulation sheet is punched and formed according to the shape and dimensions of the core plate segment that is predetermined together with the core plate material, the interlayer insulation sheet and core plate segment can be integrated without displacement. Since the composite material can be obtained, labor-saving and time-saving functions of the iron core stacking work can be obtained, and the surface contaminated by foreign metal generated during punching is limited to one surface of the interlayer insulating sheet. The function of facilitating the cleaning work and reducing the influence of foreign metal can be obtained.

[0012]

EXAMPLES The present invention will be described below based on examples. FIG. 1 is a sectional view schematically showing the insulating structure of an interlayer insulation sheet of an electric equipment iron core according to an embodiment of the present invention.
The same components as those of the conventional technique are designated by the same reference numerals, and duplicated description will be omitted. In the figure, an interlayer insulating sheet 11 is formed as a composite insulating sheet in which a ceramic fiber paper 12 and a polyester film 13 for electrical use are adhered by an acrylic adhesive layer 14, and one surface thereof (ceramic fiber in the figure). On the paper side), for example, a heat-sensitive adhesive layer 15 is provided, and the adhesive layer 15 is used to attach the interlayer insulating sheet 11 to the surface of the iron core plate segment 1 for use in iron core stacking work. This has the advantage of saving labor and time.

The ceramic fiber paper 12 is made of, for example, a mat-shaped ceramic paper made of ceramic short fibers or glass short fibers impregnated with a heat-resistant resin binder as a binder, and the resin binder is dried. A ceramic fiber paper 12 having low hygroscopicity and mechanical strength is obtained. Further, an interlayer adhesive sheet 11 is obtained by applying an acrylic adhesive on one surface and sticking the electrical polyester film 13 thereon. The interlayer insulating sheet 11 having the above-mentioned structure is used for the electrical polyester film 1
It has been confirmed that by utilizing the excellent withstand voltage performance of No. 3, it is possible to maintain the breakdown voltage and tensile strength in a pressurized state of 20 kg / cm ² that are equal to or higher than those of the conventional interlayer insulation sheet, and the ceramic fiber paper side. No decrease in the breakdown voltage measured under pressure of 20 kg / cm ² after the iron powder was sprayed on the surface of the surface of Example 2 was confirmed, and the interlayer insulation sheet 11 of the example was the same as the conventional interlayer insulation sheet 6. It has been demonstrated that it has sufficient performance as an alternative.

FIG. 2 is a perspective view schematically showing a method for processing an interlayer insulating sheet according to an embodiment of the present invention. The interlayer insulating sheet 11 is a roll-shaped or sheet-shaped interlayer insulating sheet. See
11A, which is formed as a core material 11A, and is adhered to the surface of a roll-shaped or sheet-shaped core plate material 1A by the heat-sensitive adhesive layer 15 thereof, and then according to a predetermined shape and size of the core plate segment 1. Punch and mold. If the processing method is configured as described above, the insulation-treated core plate segment 16 in which the interlayer insulating sheet 11 and the core plate segment 1 are composited without displacement is obtained, so that the metal foreign matter adhered during the punching process is obtained. If you perform the iron core stacking work to stack the insulation-treated core plate segments 16 while cleaning the
Labor saving by reducing the number of man-hours required to stack the core plate segment 1 and the interlayer insulating sheet 6 alternately to half that time,
The time saving effect can be obtained. Also, ceramic fiber paper 12
By including a resin binder as a binder as the binder, the interlayer insulating sheet 12 is mechanically reinforced and the hygroscopicity is lowered, and at the same time, the ceramic short fibers or glass short fibers as the base material become the aggregate. Since it exhibits excellent compressive deformation rate retention performance, it maintains a constant compressive deformation rate against tightening loads, has little dimensional change due to moisture absorption, etc., and has a crushed interlayer insulation sheet outside the core plate segment. It is possible to obtain a highly reliable stator core that is unlikely to run out and come into contact with the rotor and cause problems.

FIG. 3 is a schematic sectional view showing an interlayer insulating sheet according to a different embodiment of the present invention. Ceramic fiber papers 12A and 12B divided on both sides with an electrical polyester film 13 sandwiched therebetween are shown. It is different from the above-mentioned embodiment in that it is configured to be adhered and provided with an adhesive layer 15 on the surface of one ceramic fiber paper so as to be adhered and supported on the iron core plate material 11A. With this configuration, the metal foreign matter adhered to the surface of the ceramic fiber paper 12A during punching can be rendered harmless by the foreign material occluding property of the ceramic fiber paper 12A, so that the withstand voltage strength is more stable and highly reliable. It is possible to obtain an electric equipment iron core.

[0016]

As described above, according to the present invention, the composite insulation is provided between the core plate segments of the electric equipment core formed by stacking the core plate segments having a predetermined shape to insulate the core plate segments from each other. The sheet was configured as a composite insulating sheet of ceramic fiber paper containing a resin binder and an electrical polyester film attached to the ceramic fiber paper. As a result, the obtained interlayer insulating sheet has a performance that sufficiently satisfies the various characteristics required for the interlayer insulating sheet, and is excellent as an alternative interlayer insulating sheet for use in iron cores for electric equipment. In addition to providing morphological stability and withstand voltage performance, inorganic fibers such as ceramic fibers and glass fibers do not contain impurities harmful to the human body, such as mineral fiber asbestos, so conventional interlayer insulation sheets using asbestos paper are used. -The advantage of eliminating the environmental pollution problem that was a problem in

Further, an adhesive layer is provided on the interlayer insulating sheet,
Attach the interlayer insulation sheet to the surface of the iron core plate material in advance,
After that, if the processing method is configured so that the interlayer insulation sheet is punched and formed according to the shape and dimensions of the core plate segment determined in advance together with the core plate material, the interlayer insulation sheet is formed.
The core and the core plate segment are combined without any positional deviation, which has the advantage of saving labor and time for the iron core stacking work.

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing an insulating structure of an interlayer insulation sheet of an electric equipment iron core according to an embodiment of the present invention.

FIG. 2 is a perspective view schematically showing a method for processing an interlayer insulating sheet according to an embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view showing an interlayer insulating sheet according to another embodiment of the present invention.

FIG. 4 is a perspective sectional view showing a main part of a stator core of a large rotating machine.

FIG. 5 is a cross-sectional view showing an insulation structure of an interlayer insulation sheet of a conventional iron core for electric equipment.

[Explanation of symbols]

 1 Iron Core Plate Segment 1A Iron Core Plate Material 2 Iron Core Block 3 Spacer 4 Positioning Hole 5 Slot 6 Interlayer Insulation Sheet 7 Asbestos Paper Impregnated with Resin Binder 8 Plastic Film 10 Stator Core 11 Interlayer Insulation Sheet 11A Interlayer Insulation Sheet -Gold material 12 Ceramic fiber paper 13 Polyester film for electricity 14 Adhesive layer 15 Heat-sensitive adhesive layer 16 Insulation-treated core plate segment

Claims (3)

[Claims] 1. A composite insulating sheet for electrical equipment iron cores formed by stacking iron core plate segments having a predetermined shape, which is interposed between layers of the iron core plate segments to insulate the iron core plate segments from each other. An interlayer insulation sheet for an electric equipment-pile iron core, comprising a composite insulation sheet in which a ceramic fiber paper containing a resin binder and an electrical polyester film are bonded together via an adhesive layer. 2. An interlayer insulation sheet for an electric equipment-stacked iron core according to claim 1, wherein the interlayer insulation sheet is provided with an adhesive layer on one surface thereof. 3. An interlayer insulating sheet formed in a roll shape or a sheet shape is rolled or formed by the adhesive layer.
It is attached to the surface of a sheet-shaped iron core plate, and then the interlayer insulation sheet
3. The method for processing an interlayer insulating sheet of an electric equipment-stacked iron core according to claim 1, wherein the core is punched and formed together with the iron core plate material in accordance with a predetermined size of the iron core plate segment.