Modelling as being an important issue connected with the analysis and synthesis of technical objects , consists in selecting an idealized system giving the possibility to have necessary information on the modelled object itself. In order to create a physical and a mathematical model of the mechanical system, it is necessary to have a knowledge of its properties, correlations and processes that happens in that system . In the most numbers of situations, models of mechanical systems are built of rigid elements, connected by kinematical couples. These kind of systems are commonly