The diagnostic features and sources of vibration of sliding bearings of diesel locomotive turbochargers (disappearance of the negative allowance on bearing bushings, self-oscillation in the bearing, self-oscillation when the negative allowance on the bearing bushing disappears, excitation of blade harmonics, etc.) are described in brief. The results of experimental studies of diesel locomotive turbochargers equipped with cylindrical and elliptical sliding bearings are shown. The specific spectra of vibration velocity of the bearing housings (cylindrical and elliptical) in the low-frequency range are presented. Bearing frequencies have been detected in the low-frequency vibration spectrum of the turbocharger housing with cylindrical bearings, and the connection of the detected diagnostic features with defects in sliding bearings has been established. Blade frequencies of the compressor and turbines on turbochargers with cylindrical and elliptical sliding bearings have been found in the high-frequency part of the vibration spectrum. These frequencies are necessary for identifying rotor harmonics and bearing frequencies. It has been established that for a defect-free bearing of turbochargers with elliptical and cylindrical sliding bearings, the vibration velocity of the rotor harmonics and the bearing frequency should not exceed the rated values.

It was suggested to use group D engine oil with advanced properties instead of group V and G engine oils, which are used in locomotive diesel engines today, to improve the performance of the Ukrainian locomotive fleet of railways.A series of comparative laboratory studies of these oil groups was conducted to substantiate this suggestion which proved better lubrication and tribological performance of group D engine oil and allowed its performance tests.Tests conducted on diesel 5D49 for mileage of more then 100,000 km have demonstrated the advantages of group D oils, such as more stable viscosity, neutralizing ,washing and other properties. Studies on the four-ball wear test machine proved better anti-wear, anti-scoring and anti-friction properties of group D engine oil, which appear even after the continuous use of oils in locomotive diesels. Decrease in burning loss of engine oil was recorded, resulting in the decrease of oil fuel consumption for group D by 30-60% vs. the group G oil.According to the results of performance tests, group D engine oil has been recommended for the use in 5D49 locomotive diesels and some advice on its future implementation have been provided.

It has been shown theoretically and confirmed experimentally that the dispersion of dirt particles found in engine oils and working fluids affects significantly their physical properties. In particular, it has been established that if dirt particles are artificially dispersed in a lubricant, its electrical conductivity increases. This, in turn, is expected to lead to a decrease in the share of electrostatic wear of the tribo units. Such particles are also able to increase the mechanical strength (surface tension) of lubricating films, that is, to make the boundary layers more durable, due to which we can expect a decrease in wear of tribo units. In this case, the thermal conductivity of oil lubricating films with highly dispersed dirt particles does not change.

The article considers the problem of determining the rational geometric parameters of friction cable drums of capstan shunting winches. The basic technical means for performing shunting works within the cargo yards of railway stations and industrial enterprises are given. Today, shunting locomotives are the most common means of shunting works at railway stations and cargo yards of industrial enterprises. However, using them is not economically feasible for small amounts of shunting. Both sheave-type and capstan shunting winches are often used to move individual cars or groups of cars along the freight front. In the capstan shunting winches, a frictional drum of infinite coiling length is used, which rotates around a horizontal axis. It is established that the known sources give only the theoretical principles of the operation of drums of infinite coiling length and do not contain any practical recommendations for the design and operation of capstan shunting winches. The article provides a theoretical study of the forces of friction that occur between the drum and the cable, as well as between the cable lines when drums with different profiles of working surfaces are used. It was found that in shunting winches, the coefficient of friction of the rope along the drum can increase by 2.5 times, as a result of which it is necessary to increase the curvature of the profile of the drum. Also, friction forces between adjacent branches of a cable wound on a winch drum are considered. On the basis of the conducted study, recommendations on the type and geometrical parameters of cable drums of capstan shunting winches are proposed, which are aimed at extending the service life of traction cables of these mechanisms.

The use of various types of plastic lubricants (such as LZ-TsNII, ZhRO, etc.) in the axle boxes of locomotives, cars and track machines in the Ukrainian railway network causes technological inconveniences at the stage of procurement, supply and regulation of this process, moreover, their operational capabilities do not quite satisfy modern operating conditions of axle boxes of the railway rolling stock. The paper proposes to solve this problem by using a single brand of modern multi-purpose lubricant on lithium complex basis (k-Li) – MZT – in axle boxes of all types of railway rolling stock. The presented results of the comparative analysis of the physical and chemical properties of the mentioned lubricants demonstrate that the MZT lubricant completely meets the operating conditions of the axle bearings and can provide their high-quality lubrication under any conditions of operation. The tribological studies of lubricants on frictional testing machines, with simulation of their operation with rolling friction and sliding friction, demonstrated that anti-wear, antifriction and anti-cuffing properties of the MZT lubricant are much better than those of LZ-TsNII and ZhRO lubricants. It has been found out that the properties of the MZT lubricant are most effectively used under high load in friction pairs. The paper presents the results of testing the MZT lubricant in the actual conditions of operation of locomotives, railway cars and multiple unit rolling stock, which demonstrated its high efficiency and operation capacity.