The Effect of Dry Friction upon the Dynamics of a Short Eccentric Rotor: An Analytical and Experimental Study

Abstract

The paper proposes the study of dry friction by means of a short eccentric rotor. The rotor was designed and realised in the laboratory. In an ideal frictionless situation, a rotor actuated by gravity will have an angular velocity which increases indefinitely. The analytical model assumes dry friction in the bushing of the rotor and the main result reveals that the angular velocity either stabilizes around a certain value or drops to zero. Two situations of friction were considered for the theoretical model: first only dynamic friction and secondly, both static and dynamic friction are present. The analytical model of the dynamics of the rotor presents the advantage that it can be applied for diverse friction cases, from dry friction to complex dry friction and wet friction. Experimental tests were carried out on the designed and constructed device; they are in very good agreement with the results of the theoretical model.