METHOD OF MAKING INSULATION FOR WINDINGS OF ELECTRICAL MACHINES Russian patent published in 2009 - IPC H02K15/12 H02K3/32 

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering and the technology of making insulation for windings of direct current machines. The insulation made from impregnated tape should be pressed so as to remove air and uniformly distribute the binding substance. For this purpose according to the invention, a polymer film is used as one of the substrates in the glass mica tape, obtaining a multi-layer composition of alternating layers of film and glass mica. The binding substance used in such a composition is a mixture without a solvent (polyetherimide compounds), which is in a state of viscous flow and which, at impregnation temperature of 50 - 70°C (viscosity 50-150 s on B3-4) provides for penetration of the compound into the insulation. The amount of binding substance in the tape should be between 23% and 30%. The insulated winding is put into an impregnating vessel, which is evacuated and excess pressure is created by the impregnating compound. Due to presence of the polymer film, the impregnating compound does not penetrate the insulation. The insulation is pressed, thereby removing residual air and redistributing the binding substance in the insulation. Insulation made this way has stable electrophysical properties and high water- and moisture resistance.

EFFECT: improvement of electrophysical properties of the insulation, water- and moisture-resistance of the insulation made from impregnated glass mica tape.

2 cl, 4 tbl, 4 ex