The dual input single output helical gear transmission system is an important component of ship power propulsion equipment. Based on the mathematical description of the internal nonlinear parameters of the helical gear system, taking into account time-varying meshing stiffness, stiffness excitation phase difference at both ends of the parallel input, time-varying backlash, meshing damping, and comprehensive transmission error, a dynamic model of a dual input single output helical gear transmission system was established. The system bifurcation diagram, time-domain and frequency-domain curves, phase diagrams Poincar é section et al. studied the evolution of the dynamic behavior of the system with asymmetric dynamic parameters, and the results showed that:
(1) As the load ratio at both ends of the high and low parallel input increases, the stability of the system is improved, and its effect on enhancing system stability is particularly evident for helical gear pairs at the low load input end;
(2) As the load value increases, the load ratio range of the system in a stable periodic motion state gradually widens, indicating that the load ratio adjustment range of the heavy-duty system is wider;
(3) As the load value increases, although the system stability is improved, the relative vibration displacement amplitude of the two pairs of helical gear pairs increases within the instability range, and the instability vibration phenomenon becomes more severe.