The effect of square-shaped pockets position in sliding line contacts under mixed regime of lubrication

Abstract

The production of surface topography by artificial pockets is introduced as a well-known method to reduce friction and wear between conjugating surfaces under different lubrication regimes. As a result, the proper design and position of the pockets are of prime importance. This paper supports that goal and focuses on the contribution of the square-shaped textures in several inlet positions and densities on film thickness and wear of line contacts under mixed lubricated conditions. The applied load, the sliding speed, and the lubricant oil are set on a custom-built block-on-ring test rig. The lubricant film thickness is measured in real time using capacitive sensors. The wear behavior of the pocketed samples is also examined by an optical microscopy before and after the tests. The findings are compared by the results of similar studies. The results showed that using square-shaped pockets with high density in line contacts can pronounce film thickness up to 40% than the sparser pattern, which resulted in lowest level of abrasive wear. The position of the square-shaped pockets comprising the inlet lubricant flow is given a beneficial effect on starvation in line contacts, helping to lubricant replenishment into the contact.