Structural Synthesis of Eight-Bar Closed Kinematic Chains of the Fourth Subfamily Moving Links of the First Family

The study objective is to develop a method for the structural synthesis of closed kinematic chains of moving links onto the fourth subfamily of the first family. The tasks are the following: based on the universal structural system of closed kinematic chains of the first family movable links to determine the composition of solutions describing the arrangement of closed kinematic chains of the fourth subfamily movable links of the first family with the complexity of the basic chain link equal to four, chain mobility equal to six and the total number of chain links equal to eight. To identify virtual chain links and obtain combinations of kinematic pairs and links that are the basis for constructing structural schemes of eight-bar closed kinematic chains of the fourth subfamily moving links of the first family, with the complexity of the basic chain link equal to four. Using the obtained data, to consider constructing structural schemes of eight-bar closed kinematic chains of moving links of the first family on a specific example. Research methods are the method of structural synthesis of closed kinematic chains of moving links of the first family, set theory and combinatorics, virtualization, identification and coding, graph theory. The novelty of the work: the features of applying a universal structural system for determining the composition of eight-bar closed kinematic chains of the fourth subfamily moving links of the first family are given. Using a specific example, constructing structural schemes, eight-bar closed kinematic chains of the fourth subfamily moving links of the first family is considered. The study results: combinations of kinematic pairs and links are found, which make it possible to construct all possible structural schemes of eight-bar closed kinematic chains of the fourth subfamily moving links of the first family under given parameters. A diagram of an eight-bar closed kinematic chain of the fourth subfamily movable links of the first is obtained, from which single-movable eight-bar mechanisms of the first family can be formed by stopping one of the links. A diagram of one of these mechanisms is shown: a screw and lever mechanism of the first family.