Study on a Variable Stiffness Mechanism Using Wire Spring

In this paper, we discuss a variable stiffness mechanism using wire spring. We have proposed such kind of mechanism using nonlinear coil spring. We intend to apply it to CPM machine. It can change the spring characteristic continuously. However, it need wide space to apply mechanism and powerful motor to change the stiffness. Furthermore, it is difficult to design such nonlinear spring. For solving these problems we propose a mechanism with wire spring. It is easy to obtain the wire spring, because it is material of coil spring. We explain how to design the mechanism and evaluate it through a experiment.