JP2616103B2 - Manufacturing method of heat resistant coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a method for manufacturing a stator winding or an armature winding of a low-voltage rotating electric machine used in a place where the atmosphere exceeds 300 ° C.

[Prior art]

Stator windings of rotating electric machines, such as electric motors, used in places where the ambient temperature exceeds 250 ° C or 300 ° C, such as at the place where the blast furnace exits at a steel mill, the transfer path for slabs at a steel mill, or around the reactor in the chemical industry For armature windings, etc., it is required that the windings be constructed using a heat-resistant insulating material that can withstand the above-mentioned ambient temperature for a long period of time, and the windings are contaminated by moisture, corrosive gas, conductive dust, etc. There is a need for a winding having excellent environmental resistance in which voltage and insulation resistance are not reduced, and an insulating structure thereof. FIG. 5 is a partial cross-sectional view of a stator manufactured by a conventional heat-resistant coil manufacturing method, and FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. The windings of low-voltage electric motors with a rated voltage of several hundred volts are made of heat-resistant enameled copper wire or insulated wires impregnated with heat-resistant varnish with glass fiber wound around the outer circumference of the enamel coating. A coil conductor formed by temporarily winding turns is prepared, and a slot insulation made of a heat-resistant sheet such as a mica sheet made of a glass cloth base material is provided in a slot previously mounted along an inner wall surface in an upper coil 2 and a lower coil 3. Insulated by the insulation 4 in the slot and the interlayer insulation 5, separated into a slot and held by the wedge 6. In the turn part 10 (coil end part) of the coil, a loose electric wire is formed into a predetermined shape by winding the upper coil and the lower coil into a bundle with a glass tape 7 or a sheet or the like. When the winding operation is completed, the entire structure including the iron core is immersed in the heat-resistant resin 8 and heat-cured, whereby the coil, the slot insulating material, and the iron core are attached to each other to form an integrated winding, so-called turbulence. Generally, wound windings are used. Also, a unit coil formed by winding and covering a prepreg tape in which a glass fiber cloth and a laminated mica sheet are bonded with a chemically reactive inorganic adhesive to a coil conductor obtained by temporarily winding an insulated conductor in a racetrack shape a plurality of times, And forming a plurality of coils composed of the plurality of series bodies,
A step of sequentially picking up the coil sides of the plurality of unit coils into the slots, mounting the plurality of coils on the iron core, and a step of impregnating with an impregnating material of the same type as the chemically reactive inorganic adhesive and heat-curing. A method for manufacturing a heat-resistant rotating electric machine has been filed by the same applicant. (See JP-A-63-56152)

[Problems to be solved by the invention]

By the way, in the irregularly wound winding, the slot insulating material surrounding the winding in the slot and forming a main insulating portion (ground insulation) of the winding is about 1 to 2 cm from both ends of the slot toward the coil end. Since the coil end has been cut and the magnet wire is exposed, the heat-resistant varnish once impregnated in the slot decreases in viscosity as the temperature increases during heating and drying.
Since the varnish flows more easily from the end of the slot insulating material and from the coil end where there is no covering, the insulating film formed on the surface of the magnet wire and the slot insulating material at the end of the heating and drying is extremely small. Air containing polluting substances such as moisture and fouling gas can freely enter through the gap from which the varnish has flowed out. Therefore, in a high-temperature atmosphere exceeding 300 ° C., the thin insulating film is oxidized and deteriorated, and the ability to prevent the penetration of the fouling substance is reduced. Further, since the creepage distance of the slot insulating material is small, the leakage current increases, and so-called MEG defects are likely to occur. There are drawbacks. In the conventional heat-resistant coil manufacturing method, the inorganic heat-resistant impregnated resin completely solidifies the heat-resistant insulated wire from the surroundings. For this reason, due to the temperature rise when the coil is energized or the heat from the surrounding environment, when the temperature of the coil rises, a force is generated due to the difference in thermal expansion between the heat-resistant insulated wire and the impregnated resin. Cracks are generated, and short-circuits between lines are apt to occur. The present invention has a high retention of the impregnating agent,
It is an object of the present invention to provide a manufacturing method capable of obtaining a heat-resistant coil in which insulation performance is less reduced even in a fouling atmosphere at a temperature exceeding ℃.

[Means for Solving the Problems]

According to claim 1, the above object is achieved by winding and shaping a conductor bundle twisted by several wires into a coil shape, and winding a heat-resistant glass mica tape or a glass mica sheet around the formed conductor bundle. A step of forming a bundle of insulated conductors, a step of sequentially picking up coil sides of a plurality of coils made of the insulated conductors into slots, and mounting a plurality of coils in an iron core, and a step of impregnating a heat-resistant inorganic resin and heating And a step of curing. The object is, according to claim 2, a step of forming a bundle of insulated conductors by winding a glass mica tape or glass mica sheet using mica into a conductor bundle consisting of several conductors coated with an inorganic varnish. A step of winding and forming the insulated conductor into the shape of a coil of a rotating electric machine;
A step of sequentially picking up the coil sides of the plurality of coils into the slots and mounting the plurality of coils on the iron core; a step of molding and fixing a coil end protruding from the end of the iron core with glass tape; And heat curing the resin.

[Operation]

According to the present invention, according to the first aspect, a step of winding and shaping a conductor bundle twisted several times into a coil shape, and winding the formed conductor bundle with a heat-resistant glass mica tape or a glass mica sheet. Including a step of forming a bundle of conductors, a step of sequentially picking up the coil sides of the plurality of coils into slots, mounting a plurality of coils on an iron core, and a step of impregnating a heat-resistant inorganic resin and heat-curing. Therefore, the difference in expansion between the heat-resistant insulated wire and the impregnated resin due to the difference in thermal expansion is absorbed by the gap between the heat-resistant insulated wire and the glass mica tape as the radial expansion of the conductor bundle, and the thermal expansion of the insulated wire and the inorganic impregnated resin The force due to the difference can be eliminated. According to the present invention, according to claim 2, a conductor bundle consisting of several conductors coated with an inorganic varnish is peeled off, and a glass mica tape or a glass mica sheet using mica is wound to form a bundle of insulated conductors. A step of winding and forming the insulated conductor into the shape of a coil of a rotating electric machine;
A step of sequentially picking up the coil sides of the plurality of coils into the slots and mounting the plurality of coils on the iron core; a step of molding and fixing a coil end protruding from the end of the iron core with glass tape; Impregnated with resin and heat-cured, so that even if cracks occur in the inorganic varnish on the conductor surface, peeled mica is sandwiched between conductor bundles where voltage is generated and passes through the peeled mica in several layers Therefore, the insulation distance increases, and the insulation resistance increases. Further, a glass mica tape or a glass mica sheet using peeled mica serves as a cushion between the heat-resistant insulated wire and the impregnated resin, and absorbs a difference in extension between the impregnated resin and the heat-resistant insulated wire. In addition, by winding the coil end with glass mica tape, the coil end is formed and the impregnated resin is prevented from flowing out.

【Example】

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a slot according to the first embodiment of the present invention, and FIG. 2 is a perspective view of an insulated conductor according to the first embodiment of the present invention. According to the invention of claim 1, in FIGS. 1 and 2, three heat-resistant insulated wires 1 coated with an inorganic insulator are twisted by three and wound with a glass mica tape 9 to form a bundle of insulated conductors. Has formed. In particular, there is no need to be three,
It may be odd or even. A coil is formed into a predetermined shape by winding the bundle of insulated conductors electrically as many times as necessary. The coil sides of the formed plurality of coils are sequentially picked up in the slots, the plurality of coils are mounted on the iron core, the heat-resistant inorganic resin 8 is vacuum impregnated, and heat-cured. The reason why the inorganic resin 8 is used is that it has excellent heat resistance. FIG. 1 shows that the upper coil 2 and the lower coil 3 accommodated in the slot provided with the in-slot insulation
, And is held by a wedge 6. By winding the heat-resistant insulated wire 1 several times with the twisted glass mica tape 9 in this way, the heat-resistant insulated wire 1 and the glass mica tape 9 slide without the heat-resistant insulated wire 1 directly touching the inorganic heat-resistant resin 8. Therefore, a difference in expansion between the heat-resistant insulated wire 1 and the impregnated resin 11 due to a difference in thermal expansion is absorbed between the heat-resistant insulated wire 1 and the glass mica tape 9 as radial expansion of the conductor bundle instead of longitudinal expansion of the wire. . FIG. 3 is a sectional view of a conductor bundle according to a second embodiment of the present invention, and FIG. 4 is an enlarged view of a part (a) of FIG.
According to the invention of claim 2, in FIGS. 3 and 4,
A bundle of heat-insulated wires 1 made of three conductors 1a coated with an inorganic varnish 1b is wound around a glass mica tape 9 or a glass mica sheet using mica 9a to form a bundle of insulated conductors. In particular, it is not necessary that the number is three, and it may be odd or even. The bundle of insulated conductors is electrically wound as many times as necessary to form a coil in a predetermined shape. The coil sides of a plurality of formed coils are sequentially picked up in slots, a plurality of coils are mounted on an iron core, and a coil end protruding from an end of the iron core is formed and fixed with glass mica tape. Further, a heat-resistant inorganic resin is vacuum impregnated and subjected to a heat curing treatment. An inorganic resin is used because it has excellent heat resistance. The insulation in the slot is the same as in FIG. The glass mica tape 9 is formed by peeling off a woven or nonwoven fabric made of glass fiber and bonding mica 9a with a chemically reactive inorganic adhesive as a binder, and setting the binder in a semi-cured state under predetermined heating conditions. Is wound once or twice in a half lap. By bundling several heat-resistant insulated wires 1 and winding with a glass mica tape as described above, the heat-resistant insulated wire 1 does not directly touch the inorganic heat-resistant resin, and the glass mica tape 9 is placed between the heat-resistant resin and the heat-resistant insulated wire 1. It becomes cushion. In FIG. 4, with respect to the distance D ₁ of the conductor voltage is generated, the actual insulation distance D ₂ between the conductors is significantly longer, dielectric strength is increased. Therefore, even if cracks 11 are formed in the inorganic varnish 1b, there is no possibility of dielectric breakdown between the conductors 1a.

【The invention's effect】

According to the first aspect of the present invention, several bundles of the heat-resistant insulated wires are twisted into a bundle, and the bundle is wound with a heat-resistant glass mica tape or a glass mica sheet having heat resistance.
Since it is formed into a predetermined coil shape and impregnated with an inorganic heat-resistant resin, the difference in expansion between the heat-resistant insulated wire and the impregnated resin due to the difference in thermal expansion causes a gap between the heat-resistant insulated wire and the glass mica tape as the radial expansion of the conductor bundle. The force caused by the difference in thermal expansion between the heat-resistant insulated wire and the inorganic impregnated resin, which caused the cracks generated in the impregnated resin, can be eliminated. Insulating performance is improved by winding a heat-resistant insulating tape. According to the second aspect of the present invention, a heat-insulated wire is bundled by several conductor bundles, and a glass mica tape using peeling mica is wound to form a bundle of insulated wires. Because of the impregnation with the heat-resistant resin, current flows through several conductors in parallel, causing no potential difference between the conductors, even if the inorganic varnish coated on each conductor cracks Since the glass mica tape using peeled mica wound on the conductor bundle is wound, the insulation distance between the conductor bundles becomes longer because it passes through the peeled mica layer, the insulation resistance increases, and the dielectric strength of the coil increases. improves. In addition, the impregnated inorganic resin has a small thermal expansion and a large thermal expansion of the conductor, so that a difference in elongation occurs between the resin and the conductor. However, glass mica tape using peeled mica acts as a cushion between the resin and the conductor to absorb the difference in elongation. By winding the coil end with a glass tape, when the coil end is formed and impregnated with an inorganic heat-resistant resin, the resin is prevented from flowing out, and the resin adheres to the glass tape to increase the heat resistance of the coil end.

[Brief description of the drawings]

FIG. 1 is a sectional view of a slot according to an embodiment of the present invention, FIG. 2 is a perspective view of an insulated conductor according to an embodiment of the present invention, and FIG. 3 is a view of a heat-resistant coil according to another embodiment of the present invention. FIG. 4 is an enlarged view of part (a) of FIG. 3, FIG. 5 is a partial cross-sectional view of a stator by a conventional heat-resistant coil manufacturing method, and FIG. 6 is a VI-VI cross section of FIG. FIG. 1: heat-resistant insulated wire, 1a: conductor, 1b: inorganic varnish, 2: upper coil, 3: lower coil, 7: glass tape, 8: resin, 9: glass mica tape, 9a: peeled mica.

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-59-70156 (JP, A) JP-A-60-213237 (JP, A) JP-A-63-105412 (JP, A) JP-A 64-64 23746 (JP, A) JP-A-60-170449 (JP, A)

Claims (2)

(57) [Claims] 1. A step of winding and shaping a conductor bundle twisted by several wires into a coil shape, and winding a heat-resistant glass mica tape or a glass mica sheet around the formed conductor bundle to form a bundle of insulated conductors. And a step of sequentially picking up the coil sides of the plurality of coils made of the insulated conductor into the slots and mounting the plurality of coils of the iron core, and a step of impregnating with a heat-resistant inorganic resin and heat-curing. A method for producing a heat-resistant coil. 2. A step of winding a glass mica tape or a glass mica sheet using peeled mica into a conductor bundle composed of several conductors coated with an inorganic varnish to form a bundle of insulated conductors, and rotating the insulated conductor. Winding the coil into the shape of the coil of the electric machine, forming the coil, sequentially picking up the coil sides of the plurality of coils into the slots, and mounting the plurality of coils on the iron core, and forming the coil end portion protruding from the end of the iron core into glass. A method for producing a heat-resistant coil, comprising: a step of forming and fixing with a tape; and a step of impregnating a heat-resistant inorganic resin and curing by heating.