Load distribution of herringbone gears in high-speed EMUs under track irregularity

Owing to its low axial force and high load-bearing capacity, herringbone gear transmission shows significant potential for application in high-speed heavy-haul railway transportation. In this study, a rigid-flexible coupled dynamic model of a high-speed train herringbone gear transmission system is developed to investigate its dynamic characteristics under wheel-rail excitation. By comparing the time-varying meshing stiffness, tooth flank contact stress, and dynamic stress of the gear under ideal conditions (without track irregularity) and actual operating conditions (with track irregularity), the load distribution balance between the two tooth flanks of the herringbone gear in high-speed train transmissions is analyzed. The results indicate that the influence of track excitation on the herringbone gear transmission system is significantly greater than that of the non-uniform axial load. Wheel-rail impact severely disturbs the meshing state of the herringbone gear, resulting in a pronounced load imbalance between the left and right tooth flanks.