Influence of Temperature and Concentration of Additives on the Lubricity of Track Machine Oils

Abstract

The promising types of additives to hydraulic oils of track machines, which contribute to increasing the lubricity of oils, that is necessary for the introduction of resource saving in railway transport, were substantiated. On the basis of the conducted justification, two types of additives were selected for further study: pure stearic acid and a three-component additive based on carbamide A, stearic and oleic acid. These additives were used in the studies, being added to hydraulic oil I-20A in different concentrations. Methods and results of laboratory studies of the indicators of the lubricity of hydraulic oil with additives depending on the concentration of the additive and the operating temperature of the oil are given. The following indicators of oil lubricity were studied: the dynamic viscosity of the oil measured in a rotary viscometer; the thickness of the boundary lubricant film measured using the "ball stack" method; the load-carrying capacity of the boundary lubricant film measured in a special load device by establishing a load in which the electrical resistance in the point of contact between two lubricated steel balls abruptly approaches the values of resistance of the dry metal contact.