Dynamic analysis, design and practical applications of an overconstrained mechanical force generator

Erdinç, Umur
In this thesis, dynamical characteristics of existing machines are improved by coupling mechanical force generators to the machine. In short, mechanical force generators (MFG) are energy efficient, overconstrained, shaking force and shaking moment free planar mechanisms which can be used to generate a desired periodic force profile; store excess energy and release it when needed. They can reduce the energy consumption of an existing machine, or optimize other dynamical characteristics of a machine. In chapter 2, dynamic analysis of an overconstrained parallelogram mechanism is performed. For this overconstrained mechanism, the “closest” equivalent regular mechanism, in terms of a predetermined dynamical feature, is obtained. Since it is not overconstrained, dynamic analysis of this equivalent mechanism can be performed analytically. This analysis sheds light on the dynamic analysis of mechanical force generators. In the following chapter, dynamic analyses of mechanical force generators are performed using two different methods. The first method is analytical, whereas the second method utilizes a computer simulation software. The results of the two methods are compared. For a given task of an existing machine, the total energy consumption and/or the required maximum actuator power/torque can be minimized by coupling a mechanical force generator to the existing machine. An algorithm, which determines the force to be generated by the MFG for the aforementioned optimizations, is introduced. The design of the MFG which generates this desired force is then realized by utilizing a novel, iterative algorithm. Besides the kinematic and inertial parameters of the MFG, this design yields the slot profiles of the MFG, as well. Effects of certain design parameters are investigated and several recommendations regarding practical implementation of mechanical force generators are presented. The case studies that have been performed in this thesis show that energy consumption or maximum actuation power/torque of existing machines can be substantially reduced by the utilization of mechanical force generators. Thus, it is possible to reduce the initial cost and/or running cost of existing machines. 


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Citation Formats
U. Erdinç, “Dynamic analysis, design and practical applications of an overconstrained mechanical force generator,” M.S. - Master of Science, Middle East Technical University, 2017.