Modeling and Testing of an Improved HEMM Linear Motor

Electrified aircraft propulsion systems require lightweight and highly efficient powertrain components including motors. Superconducting rotor coils can help enable such high-performance motors, but keeping the superconductors at the required cryogenic temperature is a challenge. NASA’s 1.4 MW High Efficiency Megawatt Motor (HEMM) solves that problem by integrating a rotating pulse-tube cryocooler into the shaft. The cryocooler acoustic section is driven by a linear motor. This paper reports modeling, building, and testing a second version of that motor. Results reported here show significant improvements over the first version but also reveal remaining deficiencies.