Proposal of strain wave gear actuated by magnetic force

Lower limb exoskeletons with actuators aids disabled individuals in walking. However, the exoskeleton weight is greater than that of conventional medical devices such as orthoses and walking frames. In this study, we propose a novel strain wave gear for light exoskeletons, which is 50% lighter than conventional commercial strain wave gears. This gear uses magnets and yokes, rather than mechanical elements. The thin-walled elastic cylinder is deformed by the magnetic force in the gear, and the torque is transmitted by tooth engagements. The maximum torque was calculated to be 10.5 Nm using flexible multibody dynamics analyses with a magnetic force database. The outcome was efficient in development of lightweight machines.