Scaling of planetary gear stages according to gear excitation similarity

There are several cases where it is not possible to test a gearbox in its actual size. Consequently, planetary gear stages with an actual size, that does not fit, need to be scaled. Unfortunately, scaling a gear stage in general, especially a planetary gear stage, leads to a conflict between the various gear stage properties. Therefore, it is necessary to develop a scaling process of a planetary gear stage, with the purpose of maintaining excitation similarity between the original and the scaled gearbox. Finally, the scaling process is illustrated by scaling down a wind turbine gearbox.