METHOD FOR EVALUATING EFFICIENCY OF LUBRICANTS Russian patent published in 2018 - IPC G01N33/30 G01N3/56 

FIELD: testing equipment.

SUBSTANCE: method is based on the use of the upper and lower layers of friction surfaces in the presence of lubricant test layer therebetween, a molecular model of friction pair is formed with a randomized arrangement of molecules in the lubricating layer using a computer and molecular modelling program realizing the methods molecular mechanics, molecular dynamics and quantum chemistry. After placing two parallel layers of friction surfaces with lubricant test layer therebetween, it is carried out using procedures for minimization of system energy, optimisation of molecules position in the lubricating layer, after which the interfacial surface energy is found by determining energy difference of the system prior to interaction of the lubricating layer with the friction surface and after the interaction; then cyclic shift of the upper friction surface is carried out relative to the lower one, maintaining parallelism for given number of times, repeating the process of optimisation of molecules position at each shift step, as a result of which the molecules in lubricating layer take definite geometric arrangement in space; orientation coefficient is calculated by taking into account the arrangement of molecules relative to the friction surfaces according to known relationships, and order coefficient of molecules in the lubricating layer is calculated from the given ratio, then potential energy of the system is calculated by means of molecular modelling program. The orientation coefficient, order coefficient of molecules in the lubricating layer, and maximum value of potential energy of the system are correlated with shear stress and frictional force, respectively; after that, the most effective lubricating agent which has the lowest shear stress at the lowest value of the potential energy of the system and the highest orientation coefficient and the order coefficient is determined by the obtained data.

EFFECT: simplification and improvement of evaluation efficiency.

1 tbl, 1 dwg