The squeeze-film lubrication of ellipsoids

A generalized analysis for the squeeze-film lubrication of a rigid ellipsoid approaching a plane is presented for both isoviscous and piezoviscous lubricants. It is shown that the relationships for load and time of approach reduce to well known expressions when a sphere lubricated by an isoviscous fluid is considered. It is shown that for a given effective radius a sphere sinks more quickly through the lubricant than an ellipsoid. The rate of sinkage is retarded significantly by piezoviscous behaviour of the lubricant and theoretically infinite pressures are readily attained. A truncated series solution is developed to yield expressions for squeeze-film velocities and times of approach in piezoviscous lubricants. The results indicate that squeeze-film times are unlikely to be significant when spherical wear specimens are initially placed upon counterfaces, in the presence of lubricants, prior to sliding wear or boundary lubrication experiments, whereas it may be necessary to consider them in any complete analysis of the skidding phenomenon in ball and roller bearings.