SU138737A1 - The method of making electrical insulation - Google Patents

Description

There are known methods for making electrical insulation of windings of electrical machines, coils of electrical apparatus, transformers and other electrical products based on glass, glass mica IOTI glass mica tapes or combinations of these fillers, impregnated with thermosetting material, first under vacuum, then under pressure in individual form.

The proposed method of making electrical insulation is characterized in that the impregnation of a known filler is bonded; it is produced under continuous pressure until the bonding agent is completely solidified.

The method allows to increase the electrical and mechanical characteristics of the insulation.

The method of making the insulation can be carried out on a mold, the structure of which is shown in the drawing.

The mold consists of the following parts: mold body /, cover 2, made of steel; the upper 3 and lower 4 bags or rubber seals, designed to seal the inside of the mold and crimp the insulation of the pump to the required size; top 5 and bottom 6 inserts made of plastic; rod 7; heater 8 and choke I intended to supply pressure to the bags. The cover 2 can be fixed with wedges, studs or other means.

The process of making insulation is carried out according to the following technology.

The side (bottom) rubber bag 4, the lower liner 6 is inserted into the mold, the insulated rod 7 is placed, the cover 2 is inserted and fixed with the bag 3 attached to it. Then the hydrostatic pressure is supplied to the rubber bags 5 and 4. In this case, the upper liner 5 moves in the horizontal and vertical direction, pressing the insulation to the required size. After this, the insulation is heated to 80-120 ° (depending on the impregnating composition used) with simultaneous evacuation and the impregnating composition is fed into the mold. The impregnation of the insulation is carried out first under vacuum and then under a pressure of 30 kg / cm. After impregnation, the insulation is heated to 180-250 ° without decreasing the pressure on the impregnating composition, and the impregnating composition is cured (polymerization). At the end of the hardening process, the pressure from the impregnating composition and the rubber sludge is removed, the mold is opened and the core is removed.

The entire rod manufacturing process lasts 2-2.5 hours.

According to the proposed method, it is possible to manufacture insulation of Turbo-rods and hydrogenerators, as well as coils of high-voltage electrical machines.

Glass fiber mite tape is made by gluing mica paper to a glass grid using a solution of divinyl styrene rubber in gasoline in the amount of 4Vo of the paper weight.

Epoxy resins with maleic or phthalic anhydrides are used as impregnating compositions as hardeners.

The breakdown voltage of the insulation of rods manufactured in molds according to the proposed method, with an insulation thickness of 1.8-2 mm, is 85-90 kV / mm, and with an insulation thickness of 3.5 mlg - more than 100 kV / mm , which is 2-3 times higher than the breakdown voltage of the micamental insulation of the same thickness. The use of insulation made by the proposed method will significantly reduce the thickness of the insulation.

Subject invention

A method of manufacturing electrical insulation of windings of electrical machines, coils of electrical apparatus, transformers and other electrical products based on glass, glass mica or glass mica tapes, or combinations of these fillers impregnated with thermosetting material, first under vacuum, then under pressure in an individual mold, characterized that, in order to increase the electrical and mechanical characteristics of the insulation, the binder is impregnated with the binder under continuous pressure until complete atverdevani binder.