Structural Synthesis and Analysis of Spatial Mechanisms Designed from Planar- and Screw-Type Kinematic Chains

The article discusses the problem of structural synthesis of mechanisms designed from planar- and screw-type kinematic chains. Using the example of the simplest zero-mobility groups — planar dyads (two-bar groups) and screw monads (one-bar groups) — we demonstrated a synthesis algorithm, which consists of setting these groups between two links, combining them into a closed kinematic chain. When we fix any of the links in such a chain, we obtain a workable mechanism. This algorithm considers two possible options for the relative arrangement of planar- and screw-type kinematic chains. Based on the developed algorithm, we synthesized a family of five-bar planar-screw one-DOF mechanisms. We confirmed the competence of the presented algorithm by performing a mobility analysis of one of the synthesized mechanisms.