JPS58127539A - Air gap stator coil - Google Patents

Abstract

PURPOSE:To obtain an air gap stator coil having an insulating layer which has good insulating performance by forming a plastic film layer between a conductor and the layer. CONSTITUTION:A plastic film layer 3 is formed between a conductor 1 and an insulating layer 2a. The film employs a polyimide film or an ethylene tetrafluoride film surface-treated with sodium, and the layer 2a employs, for example, a mica tape lined with glass which is wound in a plurality of turns in half engagement. In this manner, epoxy resin which is impregnated to the layer 21 does not flow out via the layer 3 to the conductor 2 side, thereby preventing the resin from flowing from the gap of the fine strands 1a of the conductor 1 and obtaining the layer 2a having good insulating performance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air gap stator winding, and more particularly to an air gap stator winding including a conductor and an insulating layer.

@The so-called air-gap stator winding, which is provided in the air gap between the conductive rotor and the stator core, is placed in a high magnetic field, so it is made of thin strands with a diameter of about l■φ (hereinafter referred to as axial strands). ), for example, as shown in FIG. 1, a conductor 1 in which seven strands are twisted and transposed is wound. A mica tape made of mica silicon bonded to a backing material such as glass woven cloth is wound around the outer periphery of the wound conductor 1 to form an insulating layer 2.

All of these are impregnated with a resin such as epoxy, but in the air-gap stator winding constructed in this way, the conductor l is removed from the insulating layer 2 until the impregnated resin hardens.
Since the insulating material leaked out through the gap between the shaft strands 11, sufficient insulation performance could not be obtained.

The present invention was made in view of the above points, and its object is to provide a single-gap stator winding having an insulating layer with good insulation performance.

That is, the present invention is characterized in that a layer of glass film is provided between the conductor and the edge layer.

The present invention will be explained below based on the illustrated embodiments. FIG. 2 shows an embodiment of the invention. Components that are the same as those in the prior art are designated by the same reference numerals, so their explanations will be omitted. In this embodiment, a layer 3 of glass film is provided between the conductor 1 and the insulating layer 2a. A polyimide film was used as the glass film. That is, a polyimide film having a thickness of 0.05 mm was wound once around the outside of the conductor 1 by half a turn to form a plastic film layer 3.

Then, on the outside, a 18-thick glass-lined mica tape is wound several times in half-length to form an insulating layer of 2 m, and on the outside is a layer of tetrafluoroethylene film that is impregnated with resin and removed after rupture. (not shown) and impregnated with a resin such as an epoxy resin.

By doing this, the epoxy resin impregnated in the insulating layer 2a is prevented from flowing out to the conductor l side by the plastic film layer 3, and the epoxy resin impregnated in the insulating layer 2a is prevented from flowing to the conductor l side.
The leakage from the gap is now prevented, and an insulating layer 2Jl with good insulation performance can be obtained.

Note that a polytetrafluoroethylene film surface-treated with sodium was used as the plastic film instead of a polyimide film. In other words, 0,0 surface treated with sodium
A glass film layer was formed by winding a 4cm thick tetrafluoroethylene film once in a half-turn, and in this case as well, the same effects as in the above case could be achieved.

The results of examining the characteristics of the above embodiments will be described below. Some of the examples were those with the insulation structure shown in FIG. A sample using fluorinated ethylene film as a plastic film layer was tested.

As a conventional example C to be compared with these, the insulation structure shown in FIG.
As a comparative example, a thick glass-backed laminated mica tape was wound with the same number of turns as in Examples A and B, and a layer of plastic film 3 was placed between the insulating layer 2 as shown in FIG.
0.18- to the outside of the conductor l
The insulating layer 2b is formed by winding a thick glass-backed laminated mica tape with half the number of turns of Examples A and H.
A layer 3s of GELASTEC film is formed by winding a polyimide film of 5 mm thickness once in a half-length.
Examples A and H of glass-backed laminated mica tape with a thickness of 18 cm
The test sample was formed from an insulating layer 2C wound with half the number of turns.

The test results of these test samples are shown in the table.

This table shows the time required for dielectric breakdown after applying a voltage of 22 kV. Examples A and B took 341°323 hours, compared to 35 hours for Conventional Example C and 162 hours for Comparative Example. It has a long time until dielectric breakdown occurs, which is excellent. This is because the plastic film layer provided between the conductor and the insulating layer prevents the impregnated resin from flowing out from the insulating layer to the conductor, and the insulating layer is well filled with resin.

On the other hand, the reason why Conventional Example C was extremely poor at 35 hours was because the impregnating resin leaked out from the insulating layer to the conductor significantly, and the insulating layer was not sufficiently impregnated with the resin.

The reason why the comparative example showed a life characteristic of 162 hours, which is about half that of Examples A and B, is because only half of the insulating layer is covered with a plastic film layer to prevent the impregnated resin from flowing into the conductor. This is because the half was well filled with resin.

As described above, in the present invention, since the plastic film layer is provided between the conductor and the insulating layer, the plastic film layer prevents the impregnated resin from flowing from the insulating layer to the conductor, thereby improving the insulation. The insulation performance of the layers is well maintained, and an air-gap stator winding having an insulation layer with good insulation performance can be obtained.

[Brief Description of the Drawings] Fig. 1 is a sectional view of a conventional air gap stator winding, Fig. 2 is a sectional view of an embodiment of the air gap stator winding of the present invention, and Fig. 3 is a sectional view of a conventional air gap stator winding. FIG. 7 is a cross-sectional view of another example of the child winding. l...Conductor, 2m...Insulating layer, 3...Plastic fin 1st $2 diagram

Claims (1)

[Claims] L A gap stator winding comprising a wound conductor and an insulating layer provided on the conductor, the entirety of which is impregnated with a resin, wherein the conductor and the insulating layer An air-gap stator winding characterized by having a layer of plastic film between the winding and the winding. 2. The air-gap stator winding according to claim 1, wherein the glasstic film is a polyimide film. 1. The air gap stator winding according to claim 1, wherein the plastic film is a tetrafluoroethylene film surface-treated with sodium.