| 摘要 |
PURPOSE:To prevent a rotor coil from corona-discharging and a layer-short circuit accident from being generated, by carrying out induction heating with each shortened commutator of a rotor before drip-impregnation of insulating varnish. CONSTITUTION:A rotor 1 of a motor consists of a rotor coil 3 wound up on and around a core 2 and of a commutator 5 fixed at the end of an arbor 4. Before insulating varnish is dripped to be impregnated into the coil 3, the arbor 4 is supported to a rotor supporter 6 and a coil 8 for induction heating is worked on rotating the rotor 1 with a motor 7 and the temperature of the coil 3 is risen. Then, the overall outer circumference of the commutator 5 is covered with conductive material of copper wire or a copper spring 9 in a ring shape, and each commutator bar is shortened. Thus, a even if electromotive force is generated by induction heating the space between rotor coils 3, corona discharge is not generated between them. |
