Multi-objective optimal and modified design for wide helical gear

Multi-objective optimal design method according to the minimum amplitude of loaded transmission error (LTE), flash temperature, loads sharing and minimum vibration is proposed to improve performance of high speed and heavy-duty wide helical gears. The modified tooth surfaces are represented by a sum of two vector functions determining the theoretical tooth surface and the deviations surface. The deformation, meshing stiffness and discrete loads on contact line of gears are achieved by tooth contact analysis and loaded tooth contact analysis, and the discrete local friction coefficient is determined with elastohydrodynamic lubrication, so discrete temperature is sought out following the Blok flash temperature formula, and a 10-DOF helical gears vibration model considering excitations of time-varying meshing stiffness and corner meshing impact is established. An improved algorithm is adopted to optimize the curve parameters to obtain the best deviation surface. The results show that more uniform load distribution, lower flash temperature and improved contact ratio are realized; the corner meshing impact increases with increasing loads and rotating speeds, the system vibration gets more sensitive to the latter than the former, so the resonance sensibility is dulled, the LTE amplitude under multi-loads reflects the varying trend.