Planetary Gear with Switchable Backdrivability

We developed a planetary gear mechanism that can switch backdrivabiliy by vibrating the teeth surface. The previous study assumed that the switching parameter depends on tooth number difference between fixed and output gear. However, the backdrive reproducibility about the angular velocity was low, which caused difficulty analyzing the experimental data. Furthermore, the theoretical the switching parameter was different from the experimental results. In this study, to improve reproducibility, S45C is selected as the gear material. Moreover, this paper proposes a new condition for the switching parameter. This paper newly focuses on the average efficiency of planetary gears for the non-backdrivable condition. In the experiment, we confirmed that the angular velocity of input shaft during backdriving is reproducible. The experimental results also indicate that the switching parameter corresponds to theoretical value.