METHOD FOR MAKING INTERMEDIATE BLANK OF ELECTRIC MOTOR COMMUTATOR Russian patent published in 1998 - IPC

FIELD: plastic metal working, namely production of commutators of electric machines, particularly manufacture of intermediate blank with bearing protrusions for commutator segments. SUBSTANCE: method comprises steps of making solid cylindrical blank, calibrating it, lengthwise pressing out sleeve at forming bearing protrusions of commutator segments on inner lateral surface of sleeve by means of punch having on its working end lengthwise grooves whose cross section is identical to that of said protrusions from calibrated blank placed into cylindrical die closed at its one end due to introducing punch along incomplete length of its lengthwise grooves; without removing sleeve from punch shaping bearing protrusions of commutator segments and shells for their predetermined-length leaves in die with round through hole; removing sleeve bottom and turning its ends. Bearing protrusions of commutator segments and shells for their leaves are finally shaped in die with cylindrical cavity (having on inner surface near its outlet blanking ring in the form of annular step) by one transition at blanking sleeve bottom by means of punch and simultaneously shaping bearing protrusions on place of blanked sleeve bottom and pressing out shell for their leaves on opposite end of blank. EFFECT: lowered metal consumption due to elimination of turning operation for removing sleeve bottom at working intermediate blank of electric motor commutator. 4 dwg