JPH09215243A - Dynamo-electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an increase in partial temperature caused by a variation in flow rate of cooling air between coils at a coil end part without a decrease in rigidity of the coil end part. SOLUTION: An insulating molded part has a ground insulating layer made of insulating material for a stator coil. The insulating molded part is separated into each insulating parts with a projected part as a spacer for ensuring a distance between the stator coils when the stator coil is previously incorporated on a slot 5 in a stator core 4. The insulating molded part is mounted previously on a copper strand covered with a strand insulating layer. Then, the stator core that is impregnated and hardened with varnish is assembled thereto.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to a rotating electric machine.

[0002]

2. Description of the Related Art A conventional stator coil of a rotary electric machine is shown in FIG.
After surrounding the outer side of the coil 2 made of a bundle of the copper wire 1 wound in a hexagonal shape with the copper wire 1 wound with the wire insulating layer shown in FIG. It was inserted into the slot 5 provided in the stator core 4, and then the coil 2 surrounded by the ground insulating tape 3 was impregnated with the insulating varnish and cured. Since the coil 2 extends from the slot 5 provided in the stator core 4 to another slot, adjacent coils are arranged at a close distance at the coil end portion 7, and insulation is achieved by sandwiching the spacer 6 between the coils 2. Had secured a distance. For this reason, the position where the spacer 6 is sandwiched between the coils 2 is not fixed, and there is a problem that the rigidity of the coil end portion 7 is reduced and a partial temperature rise is likely to occur due to variations in the cooling air flow rate between the coils of the coil end portion 7.

[0003]

To obtain a rotating electric machine in which the rigidity of the coil end portion is reduced and the partial temperature rise due to the variation of the cooling air flow rate between the coils of the coil end portion is reduced.

[0004]

Rotation for mounting a stator coil comprising a copper wire having a wire insulation layer wound in a slot provided in a steel stator core and a ground insulation layer surrounding the wire insulation layer. In an electric machine, the shape of the ground insulation layer of the stator coil at the coil end is used in order to have the role of ground insulation at the same time as ensuring the insulation distance between the stator and the coil at the coil end. Characterized by using a stator coil in which a ground insulating layer formed by dividing it into multiple parts with an insulating material was attached to a copper wire wound with a wire insulating layer placed at the coil end, and the entire coil was impregnated with varnish and cured. And came to the rotating electric machine.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION One embodiment is shown in FIGS.

A copper wire 1 obtained by impregnating glass fiber with an epoxy varnish and winding a wire insulating tape in a prepreg state is wound in a hexagonal shape, and the pressure is 0.5 MPa from the surroundings and the temperature is 175 ° C.
After applying pressure to heat and bond with, tape the coil straight part 8 inside the slot and the coil bent part 9 at the slot exit part with the ground insulation tape 3 made of mica tape lined with glass cloth. Half of the width was overlapped and wound four times to obtain a ground insulating layer before impregnation with varnish. For the portion of the coil end portion 7 where the mica tape is not wound, a case 10 and a case 11 in which a vinyl ester resin containing 30% by weight of glass short fibers is formed into a shape in which the surface shape of the coil end portion 7 is divided into four. On the inner surfaces of the cases 12 and 13, a compound layer 14 made of a mixture of 95 parts of bisphenol A type epoxy, 60 parts of mica flake, and 92 parts of hymic acid anhydride was provided.
0, case 11, case 12, and case 13 were fitted into the coil end portion 7 to form a ground insulating layer before impregnation with varnish. After that, a liner material 15 made of aramid non-woven fabric is laid on each slot 5 provided on the steel stator core 4, and two upper and lower coils are installed in each slot 5, and then the coil 2 is provided with the ground insulating layer before impregnating the varnish. A varnish consisting of 100 parts of bisphenol A type epoxy and 100 parts of hymic acid anhydride was vacuum impregnated and heat-cured at 175 ° C. for 5 hours.

A comparative example is shown in FIGS.

As an induction motor in the conventional method, a copper wire 1 wound with a wire insulation tape which is impregnated with epoxy varnish in glass fiber and made into a prepreg state is wound in a hexagonal shape, and the pressure is 0.5 MPa and the temperature is 175 from the surroundings. After bonding by heating under pressure at 0 ° C., a ground insulating tape 3 made of a mica tape lined with glass cloth is overlapped around the entire circumference of the coil 2 by half the tape width and wound four times to form a ground insulating layer before varnish impregnation. . In this state, upper and lower two coils are installed in each slot 5 provided in the steel stator core 4 on which the liner material 15 made of aramid nonwoven fabric is laid, and then a spacer made of a polyester fiber mat is provided between each coil of the coil end portion 7. I sandwiched 6. In this state, the bisphenol A was added to the coil 2 provided with the ground insulating layer and the spacer 6 before impregnating the varnish.
A varnish consisting of 100 parts of epoxy resin and 100 parts of hymic acid anhydride was vacuum-impregnated and heat-cured at 175 ° C. for 5 hours.

With respect to the examples of the present invention and the comparative example, thermocouples were attached to the upper and lower and left and right positions which are symmetrical with respect to the rotation axis of the coil end portion 7, and an energization temperature rising test was conducted. Although the difference was 21 ° C., it was confirmed that a uniform temperature distribution within 13 ° C. was obtained in the example of the present invention.

Further, as a result of comparing the resonance frequencies by the tapping test of the coil end portion, it was confirmed that the resonance frequency was increased by 7% and the rigidity was increased.

[0011]

According to the present invention, the ground insulation of the stator coil of the coil end portion is performed in order to secure the insulation distance between the stator and the coil of the coil end portion and facilitate the ground insulation treatment. A grounding insulation layer formed by dividing the grounding insulation layer into multiple layers with insulating material was attached to a copper wire wound with a wire insulation layer placed at the coil end, and a stator coil with ground insulation treatment was used. Thus, it is possible to obtain a rotating electric machine in which variations in rigidity of coil end portions and partial temperature rise due to variations in cooling air flow rate between coil end portions are reduced.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a range in which an insulating tape is wound around a coil of Example 1 and a case mounting relationship.

FIG. 2 is a perspective view of a stator coil end portion according to the first embodiment.

FIG. 3 is a cross-sectional view of the case used in Example 1.

FIG. 4 is a perspective view of a coil of a comparative example.

FIG. 5 is a perspective view of a portion of a stator coil end portion in a comparative example.

[Explanation of symbols]

4 ... Stator core, 5 ... Slot, 10, 11, 12,
13 ... Case, 15 ... Liner material.

Front page continuation (72) Inventor Satoshi Ogura 7-2-1 Omika-cho, Hitachi-shi, Ibaraki Hitachi, Ltd. Electric Power and Electric Development Division (72) Inventor Nobuo Sugawara 2-chome, Omika-cho, Hitachi-shi, Ibaraki No. 1 Electric Power Company / Electric Machinery Development Division, Hitachi, Ltd.

Claims (1)

[Claims] 1. A rotating electric machine having a stator coil made of a copper wire, a wire insulating layer surrounding the copper wire, and a ground insulating layer surrounding the wire insulating layer, mounted in a slot provided in a steel stator core. In, the insulating coil for earth insulation is wound around the stator coil mounted in the slot of the stator core, and the stator coil at the coil end portion outside the slot is made of an insulating material by the earth insulating layer and the stator coil. Insulating parts formed by splitting into a plurality of parts having protrusions that serve as spacers that secure the distance between adjacent coils when assembled into the slots of the stator core are attached to the copper wire wound with the wire insulation layer. After that, the rotating electric machine is characterized in that the entire coil is impregnated with varnish and cured.