Optimization of the Power-to-Weight Ratio of an Electric Aircraft Propulsion System using Planetary Gearboxes

A novel approach to weight optimization of an aerospace electric drive using a planetary gearbox was developed. For this purpose, two different algorithms were developed for estimating the weight of an electric machine and a planetary gearbox. It is found that a drive train using a planetary gearbox decreases the total weight of the drive significantly in comparison with the direct electric drive. The total weight of the drive was reduced by all the gear ratios examined, which are greater than 3.8. The lightest configuration that includes a gearbox is 43 % lighter than the direct drive at a gear ratio of 4.59.