A worm gear has the advantages of a large reduction ratio and non-backdrivability. Because of this non-backdrivability, it can maintain a joint angle without energy consumption. Today, many robots have large workspaces that extend into the living spaces of humans, and they are required to work cooperatively with humans. In such cases, backdrivability is necessary to achieve high compliance for robots. Compliance helps robots perform cooperative tasks with humans, and protects its mechanisms and humans in the case of a collision. However, a worm gear cannot be backdriven because of the friction between tooth surfaces. Therefore, we have developed a worm gear mechanism that can switch its backdrivability using vibration that reduces friction. In this paper, we present a dynamic model of the worm gear to analyze the friction-reduction phenomenon caused by vibrations. We discuss the change in the effectiveness of the backdrivability with the change in the vibration direction. Finally, we experimentally confirm the certainty of the analysis.

中文翻译：

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蜗轮机构，可逆转

蜗轮蜗杆具有大的减速比和不可逆驱动性的优点。由于这种不可逆驱动性，它可以保持关节角度而不会消耗能量。如今，许多机器人都有大的工作空间，这些工作空间延伸到人类的生活空间中，因此需要与人类合作。在这种情况下，必须具有反向驱动能力才能实现机器人的高度合规性。法规遵从性可以帮助机器人执行与人的协作任务，并在发生碰撞时保护其机制和人。但是，由于齿面之间的摩擦，蜗轮无法反向驱动。因此，我们开发了一种蜗轮蜗杆传动机构，该机构可通过减少摩擦的振动来切换其反向驱动能力。在本文中，我们提出了蜗轮传动的动力学模型来分析由振动引起的减小摩擦的现象。我们讨论了随着振动方向的变化，可逆性有效性的变化。最后，我们通过实验确认了分析的确定性。