Advanced polymeric coatings for tilting pad bearings with application in the oil and gas industry

Under extreme operating working conditions, the oil film in hydrodynamic bearings may get destroyed, resulting in mixed and boundary lubrication conditions; subsequently, the bearing surfaces might seize and cause catastrophic failure, rendering the machine non-operable. To address these extreme working conditions, three advanced coatings are proposed in this paper: polytetrafluoroethylene (PTFE) based, polyetheretherketone (PEEK) based and aromatic thermosetting polyester (ATSP) based coatings. A specialized high pressure tribometer, with a pin-on-disc configuration, combined with boundary/starved lubrication, was utilized to simulate the tilting pad bearing׳s severe working conditions encountered inside an Electrical Submersible Pump used in the oil and gas industry. Two sets of experiments, scuffing (step load) and constant load wear experiments were carried out. The coatings exhibited excellent performance compared to bare substrate materials. Scuffing experiments showed that all three coatings exhibited improved scuffing performance and wear experiments showed that the coatings exhibit relatively low coefficient of friction and low wear rate. Among coatings investigated, ATSP coating exhibited the best wear resistance.