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Abstract: This paper proposes an experimental methodology for the analysis of the lubrication regime and wear that occur between vanes and pressure ring in variable displacement vane pumps. The knowledge of the lubrication regime is essential for the improvement of the performance of high pressure vane pumps by reducing wear, increasing the volumetric efficiency and decreasing maintenance costs. Tests using pressure rings of different materials were carried out in order to identify the best material in terms of wear and friction. The proposed methodology is based on Archard's law and takes advantage of wear experimental measurements, an empirical model for the estimation of contact pressure forces and hardness standard tests. The results of the analysis state that low wear and reduced friction can be obtained if elasto-hydrodynamic lubrication between vanes and pressure ring is established. Results have been also verified by an analytical elasto-hydrodynamic model. [Copyright &y& Elsevier]

The friction and wear behavior were studied for three materials typically found in industrial bearing applications: a Sn-based Babbitt, polytetrafluoroethylene (PTFE) and a polyether ether ketone (PEEK) composite. Test conditions were unidirectional sliding with a ball-on-disc geometry where the counter surface material was a 440C stainless steel ball (6.35 mm dia.). The tests were also in the presence of a lubricant, ISO46 oil, with the sample and contact submerged throughout the test. The relative effects of load and sliding velocities on the wear rates were assessed by means of regression analysis. Connections between wear and the materials mechanical properties, which were measured by instrumented indentation, were also made. The ranking of wear performance of the materials correlated best to the ratio of H/(E*)0.447, where H is the test material's hardness and E* is the reduced modulus for the contact. The power applied to the reduced modulus is that used in previous studies to estimate the oil film thickness for an isoviscous, elastic lubrication regime. • Friction and wear rates of bearing materials are measured in oil-lubricated sliding against a stainless steel ball. • The mechanical properties were assessed by instrumented indentation at different loads and loading rates. • Good correlation between the wear rates and the ratio between the materials' hardness H and reduced moduli E*0.447. • The H/E*0.447 ratio is proposed as a new means to rank the wear resistance of materials in boundary lubricated contacts. [ABSTRACT FROM AUTHOR]