Smaller, more powerful motors and generators

Most motors and generators use stator cores made of silicon iron, which places upper limits on their operating frequencies. Engineers at Light Engineering Inc., Indianapolis, Ind. (www.lightengineering.com), build their motors and generators with critical components made of amorphous metal or nanocrystalline materials. Such components operate at high frequencies and flux densities without generating excessive losses, the problem with iron components. Without those losses, the motors, called SmartTorq, and generators dubbed GenSmart, can operate at higher frequencies and be smaller and lighter. GenSmart devices, for example, have only 35% of the weight and 20% of the volume of conventional wound-field and induction generators. And SmartTorq motors have 60% of the weight and 55% of the volume of permanent-magnet motors. The devices also handle variable-speed operations.

The motors provide nearly constant torque with a flat efficiency curve over a wide range of operating speeds, giving them power densities 25 to 100% higher than other technologies. And for generators, the SmartGen versions do not have the reduced torque density associated with slotless and coreless designs. So a high-speed SmartGen can replace a conventional generator and gearbox with a savings in weight and volume of up to 80%.