Synthesis of Planar Mechanisms

Abstract

Design in Mechanical Engineering must give answers to different requests that are based on two cornerstones, analysis and synthesis of mechanisms. Analysis allows determining whether a given system will comply with certain requirements or not. Alternatively, synthesis is the design of a mechanism so that it complies with previously specified requirements. For instance, mechanism synthesis allows finding the dimensions of a four-bar mechanism in which the output link generates a desired function with a series of precision points or a mechanism in which a point follows a given trajectory. Therefore, synthesis makes it possible to find the mechanism with a response previously defined. Currently, there is a set of methods and rules that makes it possible to find the solution to many mechanism design problems. However, since this is quite a newly-developed discipline, there are still many problems that need to be solved. The concept of synthesis was defined in Chap. 1 as follows: synthesis refers to the creative process through which a model or pattern can be generated, so that it satisfies a certain need while complying with certain kinematic and dynamic constraints that define the problem (Fig. 10.1). Other definitions can be added but all of them will somehow express the idea of creating mechanisms that can carry out a certain type of motion or, in a more general way, mechanisms that comply with a set of given requirements. There are several classifications for different types of synthesis but, basically, most authors agree on grouping the synthesis of mechanisms in two main branches: structural synthesis and dimensional synthesis.