THE PRODUCTION OF PLASTIC LUBRICANTS BASED ON REGENERATED SYNTHETIC MOTOR OILS USED IN UZBEKISTAN

The purpose of the study is to increase the efficiency of using used engine oils as a dispersion medium for plastic lubricants. It has been established that the removal of resins, carbenes, carbides and asphaltenes from used synthetic motor oils makes it possible to obtain an oil base close to commercial base oils in terms of basic characteristics; refined oils also have a high margin of operational properties. The composition of lubricants for analogues of Lithol-24 and Solidol-Z based on refined used engine oils has been determined. Anticorrosive, adhesive and strength properties of lubricant compositions are considered.

Application of nanofluids on various performance characteristics of hydrodynamic journal bearing—A review

Bearings are designed to support the loads normally applied to the shaft, while allowing relative movement between two machine elements. Journal or sliding bearings are perhaps the most well-known sorts of hydrodynamic bearings. The journal bearings contain no rolling elements and these bearings’ design and construction are simple, but their operation and theory are complex. Due to this and other advantages, journal bearings are much preferred in engineering applications. Simultaneously, the associated research and development have resulted in reasonable progress and therefore, a thorough review of these is earnestly felt. The static and dynamic characteristics of hydrodynamic journal bearings mainly depend on the lubricant viscosity and other factors such as load, speed, friction, and eccentricity. The review analysis focused on nanofluid lubricated hydrodynamic journal bearings are one of the rare topics of interest among tribologists. The use of a nanofluid as a lubricant is very important as it significantly improves the performance characteristics of the investigated bearing. The aggregation of nanoparticles in lubricants available commercially can cause a sharp increase in pressure drop and significantly improve the lubricant viscosity, which leads to an increase in load-carrying capacity. The tribological properties of various lubricants/base oils can be augmented by nanoparticles containing the lubricant. Studies have shown that compared to other conventional engine oils the load-carrying capacity is increased with nanoparticles containing the lubricant.

Assessment of the intensity of engine oil contamination during operation

The acceleration of internal combustion engines leads to an increase in thermal and mechanical loads on the most critical parts. To ensure the required resource indicators in conditions of increased loads, it is necessary to use high-quality lubricants, the requirements for the operational properties of which are also steadily increasing. In order to ensure the necessary physical and chemical characteristics of engine oils, additives are introduced into their composition, but during operation the quality of engine oil decreases, the reasons for this are both the destruction of additives, and the accumulation of dirt particles in the oil and the ingress of fuel and coolant into the oil. The conducted studies are devoted to determining the intensity of engine oil contamination under operating conditions in the Wärtsilä 6L20 engine lubrication system and the effectiveness of the dispersing additives contained in the oil. Samples of Petro Canada and TARO oils brands were used as prototypes at the beginning of the operational period, at the time of average operating time and at the time of oil change. The dispersing ability of the oil was determined by the method of assessing the oil stain. According to the results of the research, it is concluded that when the properties of the oil change as a result of contamination, their dispersing ability remains satisfactory. This result can serve as a justification for extending the service life of engine oil, provided that its properties are monitored during operation.

Changes in the kinematic viscosity of engine oil during the operation of marine diesel engines

A prerequisite for the long-term and safe operation of marine diesel engines is the high quality of operational materials, which include engine oils and coolants. The required quality of operational materials is ensured by the introduction of additives into their composition, which are now increasingly used as nanoparticles. During operation, as a result of the destruction of additives, the operational properties of coolants and engine oils deteriorate. The conducted studies allowed us to evaluate the change in the lubricating ability of engine oils of two brands that are used in marine diesels during operation. As a characteristic of the lubricating ability of the oil, its kinematic viscosity was used. The experimental determination of the kinematic viscosity of engine oil samples having different periods of operation, and the subsequent mathematical processing of the experimental results made it possible to determine the dependencies characterizing the change in the kinematic viscosity of engine oil during its operation. The research results confirm the possibility of scientific justification for extending the use of marine diesel engine oils, which reduces operating costs and increases the environmental safety of marine diesel engines.