Nonlinear dynamics analysis of a gear system considering tooth contact temperature and dynamic wear

Increased temperature and surface wear of high-speed and heavy-load gears are inevitable. Thermal deformation and surface wear modify the position of the action line of the tooth surface and thus influence the dynamic characteristics of the gear mesh. In this study, the elastic modulus and tooth profile thermal deformation were calculated when the tooth contact temperature (TCT) increased. A dynamic wear calculation method was used to combine the dynamic mesh force and dynamic wear coefficient caused by the dynamic mesh force obtained in the nonlinear dynamics model with the quasi-static wear model to obtain the cumulative wear depth. The changed elastic modulus, the tooth profile thermal deformation and the wear depth are considered when calculating the mesh stiffness using the energy method. A nonlinear dynamics model was established by considering the effects of TCT and dynamic wear on the internal dynamic excitation of the gear transmission system. The effects of internal excitation variations such as mesh stiffness, STE and backlash on gear dynamics are analyzed, and the study showed their complex effects on gear dynamics. Comparing the bifurcation diagrams with or without considering TCT and dynamic wear reveals that the system enters chaos earlier after considering TCT and dynamic wear.