Research On The Structural Synthesis Theory And Technology Of The Planar Multi-loop Coupled Mechanisms

The mechanism is the carrier and core of the mechanical equipment and it is also the crux of the equipment with good performance.The innovative design of the mechanisms is basis of the mechanical equipment invention,and it is also essential for the invention of the mechanical equipment with the excellent performance,the function upgrade and the self-owned intellectual property.The method according to the type synthesis method of mechanisms,is the effective way of the innovation design of mechanisms,and leads to the development of automatization and intelligentialize and human-computer interaction.This paper is around the basic issues for the type synthesis and innovation design of planar multi-loop coupled linkages: namely the structural synthesis of kinematic chains,the sketching of kinematic chains,the structural analysis and the automatic innovation design method and the software platform for the planar multi-loop coupled mechanisms.Besides,according to the synthesis method and results,this paper proposes the structural synthesis of Baranov trusses,Assur groups,epicyclic gear kinematic chains and planar fractioned kinematic chains.Based on the synthesis equation sets of the link assortment arraies,contracted graphs and topological graphs of kinematic chains,the topological graph set of all the possible degrees of freedom(DOFs)kinematic chains with up to 19 links and 6 independent loops is obtained.The topological graphs of kinematic chains with the order of the screw system d=2,4,5 and 6 are also synthesized.The definition of the canonical simplified contracted graph is introduced.Based on the canonical simplified contracted graph,the method for the automatic sketching of kinematic chains is proposed.Based on the structures between the topological graphs of the planar simple joint and multiple joint kinematic chains,an aotumatic method for the sketching of the multiple joint kinematic chains is presented.Based on the DMP algorithm in graph theory,an automatic method for the planarity detection is given.The new formula of the connectivity calculation is proposed.Based on Floyd-Warshall algorithm,DFS algorithm and the subchain mobility superposition algorithm,an automatic method for the connectivity matrix calculation is proposed.Based on the loop-minimum DOF superposition set,the automatic DOF classification detection method and the DOF-hierarchy sketching method are proposed.The topological representation of the palanr mechanisms is introduced.Based on the isomorphism identification of the topological graphs of the planar mechanisms,an automatic method for the innovation design of the palanr multi-loop coupled mechanisms is proposed.The method is used for the innovation design of the hydraulic face-shovel excavators,loaders and forging manipulators.According to the structural characteristics of Baranov trusses,the structural synthesis method for Baranov trusses with up to 13 links are given.Based on the structural relationship between Baranov truesses and Assur groups,Assur groups with up to 12 links are synthesized.Structural characteristics of the epicyclic gear kinematic chains are presented,and based on the counting spanning tree algorithm with the basic incidence matrix,the synthesis method for topological graphs of the epicyclic gear kinematic chains are given.Structural characteristics of the link-and joint-fractioned kinematic chains are listed and the topological graphs of the planar link-and joint-fractioned kinematic chains are synthesized.