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 (hg/hff) in an axially loaded 6209 deep groove ball bearing (DGBB) depends on the product of viscosity, load and linear speed (ηbu). 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 ηbu, independent of the bearing size.