Influence of the lubrication model on the dynamic behavior of slider-crank mechanism with clearance

Lucas Tavares Selegatto¹; Vitor Luiz Reis²; Gregory Bregion Daniel¹

¹ University of Campinas (UNICAMP); ² Aeronautics Institute of Technology (ITA)

doi:10.20906/CPS/COB-2015-1269

Resumo

Slider-crank mechanisms are employed in many machines, such as engines, compressors and pumps. Thus, the dynamic analysis of these mechanisms is very important, since the occurrence of problems directly affect their performance and lifetime. For this reason, this work aims to evaluate the influence of different lubrication models in the dynamic behavior of slider-crank mechanism with clearance on the piston-pin revolute joint. Thereby, the dynamic model of the mechanism is obtained by Lagrange's method, considering the contact, friction and lubrication effects on the piston-pin revolute joint. In this approach, the Hertz contact model and the Coulomb friction model were considered. For hydrodynamic lubrication, analytical models were adopted for short bearing (Frene's model) and for long bearing (Pinkus and Sternlicht's model), besides the numerical model where the hydrodynamic force is obtained from solution of Reynolds equation. The results presented in this work show the influence of the lubrication models in the dynamic behavior of the mechanism and the lubrication conditions in the pin-piston revolution joint, emphasizing the differences between the hydrodynamic forces obtained from analytical and numerical models.

Palavras-chave: Hydrodynamic Lubrication; Hydrodynamic Forces; Slider-Crank Mechanism