Observations on the effects of grooved surfaces on the interfacial torque in highly loaded rolling and sliding tests

Some efforts have been undertaken to study the effects of grooved surfaces on the interfacial film thickness and torque between two contacting non-conformal surfaces under heavy loads. Transverse grooves of micrometer scale depth were engraved on polished, flat ring surfaces using established industrial methods like laser engraving and wire cutting. The grooved surfaces were then run against a polished flat surface at loads corresponding to high normal Hertzian pressures. Experiments were conducted to study the effects of the following parameters on the interfacial torque-groove depth, groove wavelength, load, inlet speed and slide-roll ratio. Experimental results were then justified, in certain cases, based on a multigrid model predicting the interfacial pressure and film thickness.