Abstract: The research on straight leaf-spring shows that the constraint-based action is essential for stiffness and accuracy of a complaint joint. So far, little research about constraint-based action has been done for the curved leaf-spring especially for the curved leaf-spring compliant joint. Building up the stiffness model and accuracy model is important for compliant mechanisms synthesis. Based on Awtar-formula, the approximate rotation angle model and axis drift model of a curved leaf-spring triangle compliant joint under simultaneous load (bending moment, tangential force and axial force) are built. The rotation angle model and axis drift model are verified by finite element analysis. The curved leaf-spring triangle compliant joint is versatile that is revealed by the FEA simulation and model computation, the character can provide a new method for the compliant joint structure synthesis.

Key words: Complaint joint, Constraint-based action, Curved leaf-spring