Experimental investigation of lubrication film starvation of polyalphaolefin oil at high speeds

The lubrication behavior of starved elastohydrodynamic contacts at high speeds was investigated in this study. A new ball-on-disc test rig with the ability to measure traction force at high speeds up to 100 m/s and lubrication film thickness at speeds up to 42 m/s was built. The relative optical interference intensity technique was used to measure the film thickness. The experimental results show that the film thickness decreased rapidly and asymmetrically when the speed exceeded a critical speed under the starved lubrication condition. Starvation is governed by the amount of lubricant available both in the inlet region and on the side of the oil reservoir. The shape of the oil reservoir becomes asymmetric and the amount of oil gradually reduces against the speed at high speeds because of the centrifugal effects, under which the oil on the outer side of the oil reservoir will be thrown away and the oil on the inner side of the oil reservoir will be compressed. The balance of oil supply and oil loss due to centrifugal force determines the starvation behavior.