METHOD FOR IMPREGNATING WINDINGS OF ELECTRICAL MACHINES Russian patent published in 2016 - IPC H02K15/12 H02K15/00 

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering, namely to vacuum-pressure methods for impregnating windings of electrical machines with pre-heating of stator windings. Method comprises sealing inner cavity of the stator frame, developing rarefaction inside vacuum chamber above the upper winding front part of 40-50 Torr, not immersed in the impregnating compound. Preliminary drying of winding is performed by passing electric current with controlling the heating process. When the winding temperature value is 40-50 °C, said temperature is maintained for 5-10 minutes with subsequent disconnection of current from the winding. Impregnating mixture consists of varnish and fine ferromagnetic filler in weight ratio (20-30)% of ferromagnetic particles and (80-70)% of the impregnation varnish. After impregnation, stator frame is unsealed and varnish is drained. Then the vessel is again sealed, rarefaction of 40-50 Torr is developed and electric current of the same value as during preliminary drying is passed. When winding temperature is 40-50 °C, said temperature is maintained for 10-20 minutes, then winding heating is continued to specified temperature of final drying.

EFFECT: technical result is increase of impregnation coefficient by in average 34,3%.

1 cl, 2 dwg, 2 tbl