Abstract
This paper proposes a new mechanism of stiffness adjustment for the purpose of lightweight and small devices. This mechanism utilizes a ball screw mechanism and a linear spring to adjust the stiffness around a rotational joint. By varying a nut position of the ball screw mechanism, the joint stiffness is adjusted. An advantage of the proposed mechanism is that elastic energy of the spring is maximum, when the joint stiffness is maximum. Therefore, the spring can be more lightweight and smaller than many of other mechanisms. In addition, the proposed mechanism requires less mechanical parts.
