Structural analysis of a third-class ten-link mechanism with two complex links

Abstract

The basis of a technological machine is a mechanism whose main task is to convert the predetermined mechanical motion of the moving link of the initial mechanism into the motion of the driven link required to perform a technological operation, with the working body of the machine positioned at a specific point of this link. If the machine structure includes a complex mechanism with two or more initial mechanisms, the motion of each driving link influences the motion law of the point where the working body is located. This can lead, for example, to its stoppage and remaining in a stationary state for a certain period determined by the execution of the technological operation. Particular attention should be paid to technological operations that involve the “transfer” of working material from one working body to another, which operate synchronously. Reliable execution of such an operation is possible either by stopping one of the working bodies or by minimizing their relative velocities. The presence of two, three, or more driving links in the mechanism structure, on the one hand, ensures a positive outcome for the high-quality execution of the technological operation, but on the other hand, significantly complicates the analysis and synthesis of such mechanical systems. When studying multi link systems with multiple driving links, it becomes necessary to develop and implement a research plan for each specific case of such complex mechanisms, taking into account their structural features. For a third-class mechanism with two complex links and three driving initial mechanisms, a structural analysis plan has been developed and implemented to determine the sequence of further studies, such as kinematic analysis. The ten-link third-class mechanism was structurally analyzed using a step-by-step examination of conditional mechanisms with a single driving link in their structure. The results of this sequential analysis allowed for the additional determination of the instantaneous kinematic parameters of the absolute motion of a link, whose motion is conditioned by its kinematic connection to the fixed link of the mechanism. Ultimately, this made it possible to analyze the third-class mechanism with three driving links in a manner typical for the study of second-class mechanisms. The proposed method for analyzing third-class mechanisms may be useful for conducting similar studies on higher-class mechanical systems