Slotless Motor with Active Metal Brazed Copper Winding for High Power Density Applications

Slotless motors are an attractive choice for high speed aerospace applications due to their lighter weight, low iron losses and superior efficiency at higher speeds/frequency of operation. To further improve the power density of slotless motors, the volume of the windings can be reduced by using active metal brazed (AMB) copper windings instead of conventional stranded wire conductors. The copper traces which comprise the stator windings have small thickness, thus minimizing eddy current losses and skin effect while keeping the copper loss to a minimum. Using AMB windings to realize the slotless winding also reduces the total effective airgap, which in turn reduces the electrical loading needed to achieve rated torque by increasing the magnetic loading.