Concept of flexible guidances (Q2736027)

Generally using smooth or rolling miniaturized guidances, the articulated mechanical structures, have reached today their limits in terms of precision. The flexible guidances based on the physical principle of elasticity do not suffer from these inconvenience. Although the methods for treating elastic guidances are known and used already 60 years, they stay up to now dispersed and fragmentary. The objective of this book is to develop a general concept of articulated structures for flexible guidances of high precision, and to open for the modern robotics a way toward a wide range of applications of this method. NEWLINENEWLINENEWLINEAfter introductory chapters 1 and 2 (Introduction; State-of-the-art), the book is divided into three parts. The first part ``Theory'' (chapters 3-6, Theoretical base; Elementary articulations; Guidance in translation; Guidance in rotation) presents the theoretical approach to the topic. Here the author gives theoretical foundations of the articulation modelling. The classic theories of rigidity and of fatigue rupture (calculations of maximal deflections) are essentially used. By the application of these theories to flexible articulations, the author deduces concepts and measures of articulated structures for flexible guidances (simplified formulas, similarity laws, abacuses, Wöhler curves etc.). NEWLINENEWLINENEWLINEThe goal of the second part `` Experimentation and technology'' (chapters 7-9, Technological limits of electroerosion; Measure of rigidity; Test of fatigue) is twofold. In the first place, the author identifies the technological limits of using electroerosion for threading in terms of precision (tolerances of manufacture), surface state and geometry. In the second place, the experimental measures aim to test the validity of theoretical models developed in the first part. The measures of rigidity are shown on 25 tables for four circular collars as well as on fatigue tests obtained for 217 circular collars. The conclusion is that, if the roughness of electroerodic surfaces is weak (\(R_a\leqslant 0.2\) \(\mu\)m), then the experiments corroborate the theoretical models. If the roughness is more substantial, then it is necessary to bring corrections in the formulas. These corrections are correlated with parameters of machining, and can be determined experimentally for a given technology of machining. NEWLINENEWLINENEWLINEThe third part ``Method and examples of conception of flexible structures'' (chapters 10-12, Flexible structures; Demonstrators; General conclusions) treats synthesis and kinematic analysis of complex flexible structures, and describes a concept permitting to maximize their work volume and to modify their rigidities. A synthesis between results of theoretical and experimental parts shows what there are flexible guidance limits in term of courses. A number of examples of flexible structures illustrates the application of the method. NEWLINENEWLINENEWLINEThis complete book, where concepts, methods, results and examples of realization neighbour harmoniously, will be interesting to all engineers dealing with mechanisms of high precision, microsystems, robotics, kinematics or micromanufactures.