Effect of bearing size on film thickness in grease-lubricated axially loaded deep groove ball bearings.

Estimating the film thickness in a grease lubricated bearing in the post-churning phase is complex because of the prevalent starved lubrication conditions. In our earlier work, we showed that the relative film thickness ( h g / h f f ) in an axially loaded 6209 deep groove ball bearing (DGBB) depends on the product of viscosity, load and linear speed (η b u). In this article, we present the results of experiments performed using bearings of different sizes – 6204, 6206, 6209 – and show that the relative film thickness maintains a power-law relationship with η b u , independent of the bearing size. • Level of starvation in grease-lubricated DGBBs correlate well with η b u. • The η b u concept is independent of bearing size. • Lubricant replenishment is a local phenomenon. • Starvation reduces film thickness dependency on speed. • Starvation increases film thickness dependency on load. [ABSTRACT FROM AUTHOR]