Research on the lubrication flow field characteristics of the main bearing of a tunnel boring machine

Abstract

The main bearing of a TBM is a large-scale, low-speed, heavy-load slewing bearing, which is crucial for effective lubrication and heat dissipation. In this paper, CFD simulations were conducted to analyze the oil-air two-phase flow under different oil supply rates, inner ring speeds, and oil immersion heights. The simulations were validated with a slewing bearing lubrication test bench. The results demonstrate that the main bearing exhibits a layered oil-air two-phase flow. When the oil supply rate is increased, the oil volume fraction in the main air phase rises, and the auxiliary thrust roller chamber is more significantly affected. Moreover, increasing the rotation speed and immersion height leads to an increase in the interface height and an expansion of the main oil phase region, while having a negligible impact on the oil volume fraction of the main air phase.