JPH0837747A - Stator for rotating electric machine - Google Patents

Abstract

PURPOSE:To provide a stator for rotating electric machine which prevents breaking of an insulating layer by a thermal stress caused by the heat generated due to a difference in expanding/contracting amount between a conductor and the stator associated with the fluctuation of the electric current flowing through a winding. CONSTITUTION:After a winding 2 formed by coating a conductor 2A with the insulating layer 2 of an insulating tape is wound around a stator 1, the stator 1 is dipped in insulating varnish 6 and dried by heating. Before dipping the stator l in the varnish 6, a flexible insulating member 4 is applied to the stator 1. Therefore, a thermal stress is generated in the insulating layer 2B due to a difference in expanding/contracting amount between the winding 2 and stator 1 caused by the fluctuation of the electric current flowing through the winding 2, but the insulating layer 2B is not broken or no dielectric breakdown occurs, because the expansion/contraction of the winding 2 and stator 1 is absorbed by the member 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stator of a rotary electric machine, in which damage to an insulating layer coated with a conductor is improved when a current is applied to a winding.

[0002]

2. Description of the Related Art In general, a stator of a rotary electric machine comprises a stator formed by stacking annular iron plates and a slot having a recess on the outer diameter side of the annular iron plate, and covering the conductor between the slots with an insulating layer. The wound winding is wound to form a rotor.
A winding formed by winding an insulating tape using mica as a conductor is manufactured by impregnating an insulating varnish and heating and drying.

[0003]

Therefore, since the insulating varnish was impregnated with the winding and the stator integrated,
The impregnating insulating varnish was interposed between the winding and the stator, and the insulating varnish firmly adhered to the winding.

In this state, during the heating and cooling cycle due to the change in the current supplied to the windings during the operation and stop of the rotating machine,
Due to the difference in the amount of expansion and contraction due to the difference in the coefficient of thermal expansion between the conductor and the stator in the winding, the thermal stress that is generated has caused the problem that the insulating layer with weak shear strength is destroyed within the layer. As a technique of this kind, Japanese Patent Laid-Open No. 4-101642 can be cited.

An object of the present invention is to provide a stator of a rotating electric machine in which the insulation layer is prevented from being damaged by the thermal stress of the heat generated by the difference in the amount of expansion and contraction of the conductor and the stator due to the change in the current of the winding. Is.

[0006]

A stator of a rotating electric machine according to the present invention comprises an insulating varnish impregnated with an insulating varnish in which a winding having a conductor coated with an insulating layer is incorporated in an iron core, and the insulating varnish is heated and dried. In the case where the winding and the iron core are fixed to each other, the flexible varnish is applied to the iron core before being impregnated with the insulating varnish and then impregnated with the insulating varnish.

[0007]

According to this structure, thermal stress is generated in the insulating layer due to the difference in the amount of expansion and contraction of the conductor and the stator due to the change in the current of the winding, but this expansion and contraction is absorbed by the flexible insulating member. The layers no longer broke to cause dielectric breakdown.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will now be described with reference to FIGS.
This will be described below.

As shown in the stator 1, a slot 1A for accommodating the winding 2 covered with an insulating tape on the inner diameter side.
Therefore, a plurality of annular iron plates 1B having a recess 3 for disposing a stator clamp (not shown) on the outer diameter side are laminated, and a stator clamp is welded and fixed to the recess 3 on the outer diameter side.

A flexible insulating member 4 such as epoxy long-chain type resin or bisphenol A type resin with a reactive diluent added thereto is applied to the slots 1A at both ends 1C and 1D of the stator 1 to further prevent insulation. A solvent-type varnish such as tung oil-modified novolac-type phenol resin is applied as the member 5, and is heated and dried to form the stator 1 shown in FIG.

Next, after incorporating the winding 2 in which the insulating layer 2B of the insulating tape using mica is wound around the conductor 2A, the insulating varnish 6 is impregnated and dried by heating to manufacture the stator 1.
The insulating varnish 6 is also interposed between the stator core 1 and the flexible insulating member 4.

When a current is applied to the winding 2 of the stator 1, thermal stress is generated in the insulating layer 2B due to the difference in the amount of expansion and contraction of the conductor 2A and the stator 1 due to the change in the current of the winding 2. Since the expansion and contraction is absorbed by the flexible insulating member 4, the insulating layer 2B is not broken and no dielectric breakdown occurs.

If the heating and drying after applying the flexible insulating member 4 to the insulation blocking member 5 is insufficient, the insulating varnish 6 is softened during the heating and drying and penetrates into the insulating layer, so that the heat resistance of the insulating layer 2B is improved. It may reduce the sex.

Therefore, the insulation blocking member 5 is applied onto the flexible insulation member 4 and dried in advance to form a film of the insulation blocking member 5 on the surface of the flexible insulation member 4 to form the flexible insulation member 4. Insulating varnish 6 avoiding contact with insulating layer 2B
To prevent the flexible insulating member 4 from penetrating into the winding 2 when the flexible insulating member 4 is impregnated with the insulating layer 2B. As a result, it is possible to prevent dielectric breakdown at the time of thermal stress generation without causing deterioration of the characteristics of the insulating layer 2B of the flexible insulating member 4.

Further, the flexible insulating member 4 is provided at both ends 1 of the stator 1.
It may be provided on C, 1D or on the entire stator.

[0016]

As a result, the life of the rotating electric machine using the stator 1 of the present invention can be extended.

[Brief description of drawings]

FIG. 1 is a side sectional view of a stator of a rotary electric machine that is an embodiment of the present invention.

FIG. 2 is a side sectional view of a stator of a rotary electric machine that is an embodiment of the present invention.

3 is a perspective view of the stator shown in FIGS. 1 and 2. FIG.

[Explanation of symbols]

1 ... Stator, 2 ... Winding, 2B ... Insulating layer, 4 ... Flexible insulating member, 6 ... Insulating varnish.

Claims (3)

[Claims] 1. A method of impregnating an insulating varnish with a winding having a conductor coated with an insulating layer incorporated in a stator, heating and drying this to fix the winding and the stator with the insulating varnish,
A stator for a rotating electric machine, comprising applying a flexible insulating member to a stator before impregnating it with an insulating varnish and then impregnating the insulating varnish. 2. The rotary electric machine according to claim 1, wherein an insulation blocking member that blocks the flexible insulating member from entering the winding during heating and drying is applied on the flexible insulating member. stator. 3. The stator for a rotary electric machine according to claim 1, wherein the flexible insulating members are provided at both ends of the iron core.