Elastohydrodynamic simulation of Rayleigh step bearings in thin film hydrodynamic lubrication

• Elastohydrodynamic simulation of Rayleigh step bearings in thin film hydrodynamic lubrication.
• Different behaviours of load capacity because of elastic deformation of less than 200 nm.
• Significant reduction of load capacity because of divergent shape in step zone.
• Higher load capacity than fixed plane bearings because of remained step shape.
• Slight improvement of load capacity because of convergent shape in land zone in some cases.

An elastohydrodynamic numerical simulation is conducted for one-dimensional Rayleigh step bearings. The numerical model incorporates the piezoviscous effect of the lubricant and the elastic deformation of the bounding surfaces to solve the one-dimensional Reynolds equation. It is found that a small elastic deformation of less than 200 nm is responsible for film formation in thin film hydrodynamic lubrication. As the film thickness decreases, the divergent shape in the step zone causes delay in pressure growth, resulting in considerable reduction of load capacity while the convergent shape in the land zone improves slightly load capacity in some cases. Rayleigh step bearings have higher load capacity than fixed plane bearings because of the remained step shape.