Thermoelastohydrodynamic Analysis Of Misaligned Plain Journal Bearing With Rough Surface

The hydrodynamic lubrication analysis considered the misaligned journal bearing caused by shaft deformation under load, surface roughness, and thermal effect of shaft-bearing system which is one of the most general and essential parts of support-transmission system in various mechanical devices was studied.The film pressure, film temperature, load-carrying capacity, end leakage flow-rate, frictional coefficient and misalignment moment of a journal bearing with different journal misalignment angle and surface roughness considering thermal effect were calculated based on generalized Reynolds equation, three-dimension energy equation and solid heat conduction equation etc. The results show that it is necessary to take the thermal effect into account in analyzing the lubrication performance of misaligned journal bearing considering surface by comparing the calculating results of lubrication performance of bearing considering thermal effect with those not considering thermal effect. The surface roughness and viscosity-pressure effect of lubricant have a great influence on the lubrication performance of misaligned journal bearing with larger eccentric ratio when considering thermal effect.The deformation-matrix calculating the thermal deformation of a bearing with some restriction is established based on ANSYS finite element method. A new method calculating the film thickness under the thermal deformation of bearing is presented.The thermoelastohydrodynamic lubrication properties of a bearing considering shaft deformation under load and roughness are studied. The results show that the thermal deformation of bearing have large effect on lubrication characteristics, especially under condition of shaft deformation, and the effect will be larger along with the rotate speed augment and radius clearance reduce. The mechanical deformation has little effect on the lubrication of bearing within the load area of this paper when the thermal deformation is not considered; but this effect will be larger when the thermal deformation is considered.