Synthesis and kinematics of a double-lock overconstrained landing gear mechanism

Abstract

In this paper, a spatial mechanism is proposed to achieve higher stiffness, higher strength and higher reliability for a landing gear system. Two non-coplanar spatial six-bar linkages are creatively designed to generate double-lock loading configuration with redundant constraints. For every spatial six-bar linkage, starting from the existing four-bar linkages, two other links are particularly synthesized to obtain double-lock function for the working configuration. Two such linkages are optimized in geometry to get a complete retraction for the sake of both providing overconstraints and saving the storage space. Based on the structure of double-lock landing gear, kinematics is conducted to obtain the complete folding and unfolding. Statics and stiffness analysis are investigated to further confirm the mechanical advantages of the landing gear system.