Experimental study of wear of model friction pairs lubricated with contaminated oil

The results of tribotests of block-on-ring friction pairs, which are analogs of piston–liner friction pairs of axial-piston pumps, are presented. It has been shown that, when the pairs are lubricated with oil that contains inorganic contaminants, the wear rate of the steel specimen is more than 200 times higher than that of the bronze specimen. It has been found that the concentration of contaminants in oil of 0.02–0.03% is permissible for block-on-ring friction pairs. The dependence of the wear rate of the specimens on the concentration of the solid contaminations is described by a logarithmic function, while the dependences of the coefficient of friction and the contact temperature on this concentration are described by hyperbolic functions. This has made it possible to assume that the wear of the specimens is determined by the hydroerosion component, which enhances the abrasive effect of the solid contaminations.