Research on the line-arc-line constant-torque flexure hinge (LAL-CTFH) based on improved pseudo-rigid-body model (PRBM)

In order to enlarge the proportion of constant-torque output, a new type of constant-torque flexure hinge based on line-arc-line segment (LAL-CTFH) is designed. The LAL-CTFH has the characteristics of good constant-torque output performance, simple structure and easy manufacturing. The improved pseudo-rigid-body model (PRBM) method named four-bar linkage PRBM (FB-PRBM) for the LAL-CTFH is proposed to analyze the torque-angle characteristics of LAL-CTFH. The method is verified by finite element analysis (FEA). Furthermore, the constant torque output characteristics of LAL-CTFH are optimized. Theoretical analysis, FEA, physical prototype production and experimental test of the optimized model are carried out respectively. The results show that in the range of 0-40, the proportion of constant-torque output can reach more than 65%, the error between theoretical value and FEA value is less than 1%, and the average error between theoretical value and test value is less than 5%, which verifies the feasibility of the design scheme and the validity of the theoretical analysis.

Automated summary

In this study, a new type of constant-torque flexure hinge based on line-arc-line segment (LAL-CTFH) is designed to enlarge the proportion of constant-torque output. The LAL-CTFH exhibits good constant-torque output performance, simple structure, and easy manufacturing. The torque-angle characteristics of LAL-CTFH are analyzed using an improved pseudo-rigid-body model method, and the method is verified by finite element analysis. The optimized model shows promising results in terms of constant torque output, confirming the feasibility of the design scheme and the validity of the theoretical analysis.