バックドライバビリティ切替可能な遊星歯車減速装置の検討

―第2報：切替に適した条件とバックドライブの挙動観察―

抄録

General industrial robot arms adopt no-backdrivable gear reducers, which can maintain its posture with low electric power. On the other hand, for a collaborative robot, the compliance is required. To achieve both high compliance and posture maintenance, switchable backdrivability is required. 1st report of this study showed that vibration enables to switching backdrivability of a planetary gear reducer. To select the vibration actuator, this report clarifies switching conditions: tooth number of the fixed gear, and tooth number difference between fixed and output gear. In the experiments, switching backdrivability occurred if the tooth number difference was 1, and the planetary gear was more likely to backdrive if the tooth number of the fixed gear was smaller. Moreover, we observed the behavior of the output shaft during backdriving. We found that the output shaft speed of the planetary gear converged, and that the output shaft stopped when the vibration was stopped.