Characteristics of internal flow field and convection heat transfer in planetary gear reducer of shield machine

Based on RNG k-ε turbulence model and dynamic grid technology, the internal fluid dynamics model of splash lubrication three stage planetary gear reducer system is established. The distribution of lubricating oil and convective heat transfer characteristic in the system at different input rotational speeds are analyzed. The results show that at high speed condition, the oil gas mixing volume and the degree of atomization of lubricating oil are higher, and the convective heat transfer coefficient of tooth surface is larger, and it takes less time for the convective heat transfer coefficient to reach equilibrium. Meanwhile, the mean convective heat transfer coefficient on the tooth surface of sun gear, planetary gear and ring gear decreases successively.