PROCEDURE FOR DETERMINATION OF TEMPERATURE STABILITY OF OIL LUBRICANT Russian patent published in 2011 - IPC G01N33/30 

FIELD: machine building.

SUBSTANCE: procedure consists in lubricant sampling, in dividing sample into equal parts, in heating each part at atmospheric pressure without access of air, and in fumes condensation. Also, each successive part of the lubricant sample is tested with temperature increased at a constant value. Upon heating each part of lubricant is tested during not less, than two hours at a tribometre of "ball-cylinder" pattern. Direct current is run trough a friction pair from a stabilised current source and a diagram of deformation changes is recorded. Upon tests duration of plastic and elastic-plastic deformations is determined on base of the diagram of deformation changes. Further, there is determined coefficient of electric conductivity of friction contact at set wear by formula C_e=I_φ.c/I_S, where I_φ.c and I_S are correspondingly values of current running through a friction contact at friction and specified current at static position of the friction pair of 100 mcA. Successively, there is determined duration of elastic deformation with consideration of formation of protective layer of lubricant oil between the ball and cylinder as product of duration of elastic deformation action taken from the diagram by the coefficient of electric conductivity. There is evaluated summary duration of plastic, elastic-plastic and elastic deformations and there is plotted graphic dependence of summary duration of plastic, elastic-plastic and elastic deformations from temperature of the test; temperature stability of lubricant oil is determined on base of this graphic dependence.

EFFECT: increased information value of determination.

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