The Analysis on Influence of Nonlinear Dynamics Characteristics for Gears System Caused by Contact Ratio

The 6-DOF dynamic model of gear transmission system has been established by energy method which includes the support stiffness, backlash and time-varying meshing stiffness. The meshing stiffness of High Contact Ratio (HCR) gear transmission system and Low Contact Ratio (LCR) gear transmission system were calculated by using finite element method. The support deformation displacement was solved by using Runge-Kutta method, considering supporting clearance of gears, the support deformation displacement would deviate from action line, and otherwise its deformation is along action line. The bifurcation characteristic of relative displacement on the gear action line of HCR and LCR gears system caused by rotating and damping, and backlash was studied in this paper. The research results reveal that the chaotic working area and vibration amplitude of HCR gears system is less than that of LCR, and the stability of periodic motion of HCR is better than LCR as well. The curves of dynamic load coefficient of HCR gears and LCR gears varying with damping ratio and backlash are compared, under the certain damping ratio and backlash condition, resonant zone of gear system presents multiple summits, which makes the vibration complex. Damping ratio and backlash have a strong effect on vibration, under the same conditions, the dynamic load coefficient of HCR gear is smaller than the LCR gear. Consequently, the HCR gear is significant to reduce vibration and noise in the gear transmission.