Modified Radial Bearing Wear Resistance Assessment with Respect to Compressibility

Polymer composite materials in the form of antifriction coatings arewidely used nowadays in heavily loaded low-speed tribosystems of various machines, providing significant resources for friction units. The use of liquid lubricants makes it possible to expand the speed range of their applicability since it provides a transition from self-lubrication boundary friction to liquid friction under hydrodynamic conditions. Then, coatings will be active during starts and runouts, and lubricant will work during stationary mode. Liquid lubricant moving in the working gap inevitably contains atmospheric gases, that significantly affect the performance characteristics of a lubricant, and primarily, its compressibility. Therefore, the introduction of the compressibility parameter into the model allows a more accurate prediction oflubricant behavior and lubrication efficiency in various bearing operating modes. This study includes the development and analysis of a mathematical model of a micropolar lubricant for a polymer-coated bearing on the bearing sleeve support surface. The modified bearing design provides for a polymer coating with a groove, which improves the distribution of lubricant and increases the durability of the system. The novelty of the work lies in the methodology development for design engineering analysis of thepolymer coating journal bearingwith a groove, taking into account compressibility, allowing to determine the value of the main tribotechnical parameters. The aim of the work is to assess wear resistance of the modified design of journal bearing, taking into account the compressibility of the micropolar lubricant. Based on the motion equation of the liquid lubricant under study, the continuity equation and the equation of state, new mathematical models were obtained taking into account the compressibility of the lubricant. The results of the study showed that the modified design of the bearing with a polymer coating and groove significantly improved its performance. A decrease in the friction coefficient value and an increase in the bearing capacity of the bearing in comparison with conventional designs were noticed. The modified design of the journal bearing allowed clarification of friction coefficient by 8-11% within the range of the studied modes, taking into account an additional parameter - the lubricant compressibility.