Fluid Film Lubrication with Nonlinear Four-Element Viscoelastic Fluids (3rd Report, Parallel Circular Bearings in Normal Approach)

In the first paper, a modified Reynolds equation for nonlinear viscoelastic fluids based on nonlinear four-element model was derived. In the second paper, the effects of viscoelastic behavior on the performance of parallel circular squeeze bearings oscillated sinusoidally was clarified by comparing theoretical results with experimental ones. This paper presents theoretical and experimental studies on fluid film lubrication with nonlinear viscoelastic lubricants between parallel circular plates in normal approach. As the upper plate of the parallel circular bearings falls by its own weight, the film pressure and the film thickness are calculated by solving simultaneously the modified Reynolds equation and the equation of motion of the upper plate. In addition, the experiments using the viscoelastic fluids as lubricants are carried out, and it is found that the experimental results are in good agreement with the theoretical ones.