METHOD FOR DETERMINING THERMAL RESISTANCE OF LUBRICATING OILS Russian patent published in 2012 - IPC G01N33/30 

FIELD: machine building.

SUBSTANCE: oil sample is taken and divided into equal parts; each sample is heated; at that, for each subsequent portion of oil sample the test temperature is increased by constant value and each portion of oil probe is tested after heating during at least two hours on three-ball friction machine with "ball-cylinder" friction circuit; direct current is passed through friction pair from stabilised power supply; current record diagram is recorded; then, according to the above current record diagram there determined as per minimum current value is conductivity coefficient of friction contact K_e and shaping time of protective boundary layers r_bls on friction surfaces; then, according to the formula there determined is intensity coefficient of mechanical-chemical processes K_mcp K_mcp=K_e·t_bls; shaping velocity of diameter of wear spot V_wf is determined V_wf=U/t_bls, where U - mean arithmetic value of diameter of wear spot, mm; curves of friction contact conductivity coefficient, shaping time of protective boundary layers on friction surfaces, intensity coefficient of mechanical-chemical processes and shaping process of wear spot diameter vs. test temperature are built, and thermal resistance of lubricating oils is determined as per temperature range of shaping of adsorption, chemisorption and modified protective boundary layers.

EFFECT: improving the accuracy of determination.

1 tbl, 4 dwg