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, whereby the temperature increases continuously until failure. The temperature and flow-field distributions are complicated during this process. Limited research exists on the temperature and flow-field distributions and on heat generation of the transmission system during LOL. This study uses the computational fluid dynamics method to establish an oil–gas, two-phase flow model for the asymmetric bearings, and calculate the oil volume fraction on the bearing surface. In addition, a dynamic heat generation calculation method was proposed based on the kinematic viscosity change of the oil–air mixture during the LOL process. The temperature distribution of the large and small rollers and raceway surface during the LOL process was analyzed using a simulation method. The injection parameters were optimized to avoid gluing of the large roller. The internal temperature distribution has a strong positive correlation with the lubricant distribution during the LOL process. Moreover, the lubrication and temperature distributions on the large roller side are worse. A temperature reduction of approximately 25% is possible upon the increase of the number of oil inlets.

Transient Thermal Analysis Model of Damaged Bearing Considering Thermo-Solid Coupling Effect

“…The calculation methods for heat transfer and temperature distribution of bearings are mainly divided into finite element method [ 23 ] and thermal network method [ 24 ]. Compared with the finite element method, the thermal network method has advantages such as mesh density, settable nodes and easy setting of boundary conditions [ 25 ]. Some scholars have studied the number of nodes [ 26 ], the distribution form [ 27 ] and the boundary setting method [ 28 ] of the network, and further developed the transient thermal network model of the bearing system [ 29 ], which can forecast the bearing temperature more precisely than the original steady state model.…”