Dynamics analysis of helical gear considering de-meshing and reverse impact with EHL lubrication condition.

The purpose of this paper was to study the evolution and dynamic characteristics of the helical gear system co-existence response considering the occurrence of de-meshing and reverse impact under lubrication conditions. The double-three tooth alternate meshing model of a helical gear was established, and the time-varying geometric parameters, motion parameters, and load distribution of positive meshing and reverse impact were analyzed, respectively. The variation of oil film parameters and the coupling between oil film stiffness and meshing stiffness of a gear system were studied according to the equivalent lubrication model of a helical gear. Considering the phenomenon that the meshing state changed from positive meshing to de-meshing and reverse impact, the dynamics model was established. The global bifurcation diagram, the attraction domain, the phase portrait, and the Poincaré section were used to analyze the evolution of a coexistence response and dynamic characteristics with helical gear system parameters.