Kinetostatic analysis of a scissor jack mechanism powered by a tetrad RRR-Ta-RRR

Abstract

In a paper previously published by the authors, kinematic analysis of a jack mechanism driven by a motor tetrad was done. For the actual design of the mechanism, the forces and moments acting on the kinematic elements that are part of it must be determined. Also, the driving force in the hydraulic cylinder must be determined, so that the mechanism works in good conditions, for a certain technological task imposed by the design theme. The present paper makes the kinetostatic analysis of the mechanism studied, from the kinematic point of view. Therefore, the reactions in the kinematic couplings of the mechanism, as well as the driving force of the hydraulic cylinder, are determined. In order to determine the reactions of the kinematic couplings, as well as the driving force of the hydraulic cylinder, the masses of the elements, the moments of mechanical inertia, as well as the load force acting on the jack were considered. The results of the calculations were graphically represented, in reaction patterns. In order to verify the correctness of the calculations, the balance force (the hydraulic cylinder motor force) was determined by both the kinetic and the virtual power method, and the results are the same.