Design of Accordion Spring for Roller One⁃Way Clutches

Generally，a one‑way clutch uses coil springs to push and energize the rollers. However，clutches with coil springs are hard to assemble. Moreover，using coil springs，the rollers are prone to bear eccentric load during operation，which decreases the reliability of the clutch. In order to increase the manufacturability and durability of the one‑way clutch，an accordion spring is proposed. First，the equivalent spring constant is derived using energy method. After that，a rigid flexible coupling finite element model is established to analyze and discuss the piecewise linear property of the spring’s stiffness characteristic. Based on the equal stiffness assumption，a parametric design method that uses length as constraints and load as boundary conditions is further proposed to design the spring. Finally，several accordion springs are made to carry out an experiment，which validates the accuracy of the theoretical model，the finite element analysis（FEA）model and the parametric design method.