Possible Measures to Extend the Service Life of Diesel Fuel Pump Main Components

Abstract

During the operation of a high-pressure fuel injection pump, the friction surfaces of the main elements are subjected to various mechanical, thermophysical and hydroabrasive effects, which increases the wear rate of precision elements and reduces the cyclic fuel supply through the cylinders. The purpose of the research is to increase the resource of the main elements of in-line high-pressure fuel pumps by modernizing the power supply system. The main factor affecting the performance of precision elements is the presence of carbovalt in hydrocarbon fuel, that is, mechanical impurities in the form of an abrasive that circulate throughout the entire circuit of the power supply system, can pass through the filter element and get into the junction of precision elements during the injection cycle, where they are pinched and abraded work surfaces. In addition to mechanical impurities, hydrocarbon fuels may contain surfactants such as sulfur, phosphorus, etc. Under certain conditions, this also accelerates the wear rate of friction pairs, especially at temperatures above 50°C. With an increase in temperature, the lubricity of hydrocarbon fuels decreases, since sulfur compounds are activated, which destroy the structured surface at the boundary of friction pairs. To reduce this effect, it is proposed to limit the increase in temperature in the diesel power system by installing a radiator with a fan. With temperature limitation in the diesel fuel system, the wear intensity will be lower, the viscosity will be consistently higher by 2 times or more, which will reduce fuel leakage in mating surfaces. The above analytical expressions indicate that the size of the fuel leakage depends on the Reynolds number. With an increase in viscosity, the Reynolds number decreases several times, while the consumption coefficient and fuel leakage through the gaps of the friction pairs are significantly reduced. The proposed measure makes it possible to preserve the lubricity of the fuel, reducing wear and increasing the service life of the main elements of the fuel injection pump.