Induction brazing of short circuit-ring
The shortcut to better short-circuit ring brazing
Brazing the short-circuit ring (SCR) is a crucial step when manufacturing motor rotors. And as more and more companies are discovering, induction technology is unrivaled as the heat source for brazing. Climber Zhao of EFD Induction China explains what makes induction heating the natural choice for rotor brazing.
Induction heating offers numerous advantages over traditional flame methods for brazing SCRs. One key advantage is that induction generates a more homogeneous temperature distribution around the SCR. Also, as induction heating can be very precisely controlled, overheating of the copper bars is avoided. Finally, induction heating is fast. Its accuracy and repeatability means it can boost throughput without sacrificing quality.
SCR induction brazing can be done in two ways: single shot and segment brazing. The major difference between the two methods is that the former needs more heating power. When the diameter of the SCR is less than 1200 mm, single shot brazing is used. EFD Induction’s series of Sinac universal power generators provide a wide range of heating power from 25 KW up to 200/320 KW. A temperature regulating system can be integrated into Sinac for closedloop control of the brazing power. Both the set and real time temperature curve can be displayed on the Sinac’s monitor and stored in the memory stick at the ECU. Also, Minac’s ECU can monitor, print and store the feedback temperature. Normally there are two ECU-controlled pyrometers in the system: one for measuring the temperature in the SCR and the other for measuring the temperature on the copper bar to ensure it reaches the brazing temperature.
EFD Induction can provide customized, turn-key solutions for virtually any SCR brazing task. These solutions include the equipment, optimized temperature curves, customized coils and a comprehensive range of training and service support.