Simulation of mechanical drives with generalized power losses

A simple method for the mathematical modelling of mechanical drives is discussed. The suggested procedure permits to take into account not only inertias, speed ratios and torsional stiffnesses of the transmission, but also the main kind of losses as viscous damping effects and Coulomb friction losses. An example of application of this method is presented: a model of an actuating system for helicopter applications was developed, which was basically composed of an electric motor, a gearbox, an epicyclic gear reducer, working as a differential and transmitting mechanical power to two separate actuators, one rotary and one linear. The results obtained suggested that this method seems to be particularly suitable to emphasize the influence on the dynamic behaviour of the system of elements with low efficiency such as worm gears, screw and nut drives, high speed ratio epyciclic gear trains, etc.