Abstract:

In order to reveal the effects of surface texture on the tribological performances of journal bearings for themicro- texture optimization design,a numerical slip boundary condition with double coefficients was determined tocharacterize the comprehensive effect of the macroscopic/microscopic interaction and was applied to the journalbearing surfaces with controlled micro- textures.Then,the cavitation was modeled by using a phase change model,and the effects of such macroscopic parameters as the surface texture location and its area on the load- carrying ca-pacity and the cavitation were investigated.Finally,the proposed numerical slip boundary condition with double co-efficients was verified by using an experimental bearing reported in a reference.Theoretical analysis results showthat (1) the surface texture in the cavitation region has no effect on the pressure of the lubrication film and theload- carrying capacity of the bearing; (2) there exists a low- pressure effect at the front of the texture region but adynamic- pressure effect at the end; (3) the textures in the hydrodynamic pressure- rising region may increase theload- carrying capacity in a positive correlation with the area of texture surface in this region,while the textures inthe pressure- dropping region may reduce the load- carrying capacity and aggravate the cavitation.

Key words: journal bearing, surface texture, velocity slip, load- carrying capacity, cavitation