METHOD OF MANUFACTURE OF BRUSHES FOR ELECTRIC GENERATORS AND MOTORS Russian patent published in 1997 - IPC

FIELD: electric equipment of underground railway cars, etc. SUBSTANCE: the method consists in mixing of source materials, moulding, thermal treatment, fabrication of blanks from thermal-treated blocks, their impregnation with aqueous solution of phospolyol, during; the method is featured by the fact that, prior to impregnation, phospolyol is heated to a temperature of 80 to 100 C, then a 45 to 55 - percent aqueous solution of phospolyol is prepared in autoclave, cooled down to the room temperature, blanks are impregnated in autoclave at a pressure of 0.92 to 0.96 kgf/sq.cm, and impregnated blanks are dried at a temperature within 205 to 300 C. EFFECT: facilitated procedure. 1 tbl