Quasi-static Study of Gear Mesh Stiffness of a Polymer-Metallic Spur Gear System

Plastic gears are becoming increasingly reliable in modern industry. The study of the gear mesh stiffness can give a better understanding to their dynamic behavior. For metallic gear set, gear mesh stiffness has been widely studied. However, for plastic ones, there is still work to be done to accurately describe the impact of the material’s viscoelastic behavior on it. A quasi-static investigation can give a better understanding to a long-term gear meshing. In this study, it is proposed to perform a quasi-static simulation on a polymer-metallic spur gear system. The viscoelastic behavior of the polymer is modelled using a rheological model, which is Generalized Maxwell Model (GMM). The gear materials are chosen to be steel verses nylon 6,6. For this type of gear pairs, deformation occur only on the polymer gear due to the huge difference in the materials Young’s modulus. The quasi-static speed of the pinion is selected so that the strain of the polymer gear tooth can be approximated to achieve full recovery before the beginning of the next engagement. Therefore, the gear mesh stiffness found by this quasi-static study is compared to that used in metal gear systems.