Heat-flow coupling variation in double-row tapered-roller bearings during the loss of lubrication process

Abstract

Loss of lubrication (LOL) is a severe problem in transmission systems wherein the temperature increases continuously until failure. The temperature and flow-field distributions during this process are complicated. These distributions and the heat generation of the transmission system during LOL have not been adequately studied. In this study, we used computational fluid dynamics to establish an oil–gas, two-phase flow model for asymmetric bearings and calculated the oil volume fraction on the bearing surface. A dynamic heat generation calculation method was proposed based on the kinematic viscosity variation of the oil–air mixture during the LOL process. The temperature distributions of the large and small rollers and raceway surface during the LOL process were analyzed using a simulation method. The injection parameters were optimized to avoid the gluing of the large roller. The internal temperature distribution was found to have a strong positive correlation with the lubricant distribution during the LOL process. Moreover, the lubrication and temperature distributions on the large-roller side were worse than those on the small-roller side. A temperature reduction of approximately 25% can be achieved if the number of oil inlets is increased.