Contrast verification and calculation of herringbone gear tooth root dynamic stress

To accurately calculate the herringbone gear tooth root dynamic stress, nonlinear herringbone gear vibration model of twelve degrees of freedom is established considering transmission error, meshing stiffness, corner mesh impact, and backlash. New method for calculating tooth root dynamic stress is put forward considering the influence of real-time dynamic load on the load distribution coefficient. Taking a ship herringbone gear transmission system as an example, the results consistently indicate that herringbone gear tooth root dynamic stresses both increase with the increasing of load torque and driving wheel rotational speed. With the external load increases, the relative fluctuations of the dynamic stress in meshing tooth root decreases first and then increases due to the influence of teeth backlash. Numerical simulation and experimental data are in good agreement. The method can more accurately reflect the trends of tooth root stress fluctuations.