On the running-in nature of metallic tribo-components: A review

Fierce rivalry in the transport market raises serious reassessment and implementation of new approaches to logistics companies and trade enterprises in marketing of goods. To maintain the volume of domestic sales and output to the external one, producers and trading firms are forced to expand their trade and economic relations that occur in other regions. The integration of the world economy and policy orientation of foreign trade to free trade greatly simplify the task of setting up the free trade and economic connections, but the question is how quickly and efficiently, with the least costs, it is necessary to put the goods in the right region to the customer.In modern market conditions, international container transportation of goods between Ukraine and the European Union countries has a prospect of development, as each year the number of orders in transport and logistics enterprises increases. After analyzing the status of orders, the problem has been detected and widely connected with the method of organization of container cargo delivery in international communication and the formation of rational technology of serviced. To solve this problem a method of logistic approach to the system of containers transportation has been proposed based on the cybernetic model „white box“. The initial stage of its implementation involves formation of the limitation system of input parameters and factors that are consistent with the needs of the customer firm and the company performing transportation. Ten alternative order services schemes, each of which takes into account the possible combinations of operations, has been proposed.Based on the company „Inter Trans Logistic“, which serviced the order of the company „Agricultural Holding August“ for the transportation of rape seeds, 10 tons of corn on demand and a portion of sunflower oil 20,000 liters, according to their applications for transportation, a logistic approach using a cybernetic model „white box“ has been implemented. Based on the mathematical models of changes in the total costs of the international container cargo shipping company of the customer, it has been shown that the maximum expenses are occurring in the implementation of the scheme 1 service order. In that case, the costs have been in the range of 848.72 to 7455.41 US $, according to a certain series of experiments. Based on the condition of the minimum cost function for container transportation, scheme 1 has been chosen as limiting scheme of service order against which the assessment carried out changes of the total costs in the implementation of other schemes. In percentage display according to Scheme 1, the following percentage intervals have been deducted for the reduction of sales costs: Scheme 2 - 12.70 to 34.98%; Scheme 3 - 2.93 to 12.00%; Scheme 4 - 2.06 to 10.88%; Scheme 5 - 1.69 to 4.25%; Scheme 6 - 0.87 to 3.28%; scheme7 - 0.97 to 2.58%; Scheme 8 - 1.64 to 4.45%; Scheme 9 - 2.66 to 11.77%; scheme 10 - 2.33 to 9.94%.The results of experimental studies indicate that when the proposed methodology of the logistic approach, using the „white box“ based on the company „Inter Trans Logistic“ to international container transportation of goods in relation to the application of the company „Agricultural Holding August“ for transportation, the scheme 2 sequence of transport operations has been effective. In its realization the costs for 12.70 to 34.98% has been decreased in comparison with the marginal service scheme.

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Realization of the logistic approach in the international cargo delivery system

A possibility has been investigated to diagnose the condition of a cylinder-piston group in the diesel engine KamAZ-740.63-400 for trucks KamAZ-6460 after a 60,000 km run. The following diagnosing parameters have been selected: a crankcase gas pressure, the compression and vacuometric properties of a cylinder-piston group. A special feature of these mated parts is that they maintain the normal combustion process in the diesel engine cylinders, as well as its resource. We have determined the boundary limits for diagnosing a crankcase gas pressure ‒ 2.39‒2.41 KPa. Based on data about the crankcase gas pressure, the examined trucks revealed malfunctions on the runs of 36,000 km, 48,000 km, 60,000 km. Given the rules for assessing the characteristics of compression-related faults, the minimum compression value for the diesel engines was 30.05 MPa or its difference among the cylinders did not exceed 10–12 %. The data on compression helped detect faults after 48,000 km run and 60,000 km run. We have determined the boundaries of wear based on the vacuometric parameters: maximum vacuum – 69–86 KPa; residual vacuum – 26–41 KPa. Control of the vacuometric properties of a cylinder-piston group has revealed faults in the diesel engines over their run interval of 36,000–60,000 km. An entropy approach has been applied to estimate the informativeness of the appropriate diagnosing parameters in bits. The informativeness level of a crankcase gas pressure is 0.329 bits, compression in cylinders – 0.249 bits, vacuometric indicators – 0.582 bits. This study allows the rational formation of the diesel engine condition diagnosing complexes during technical operation, as well determining the prerequisites for malfunctions. The data acquired are important for transportation and service enterprises and companies that manage freight vehicles

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Development of a system for determining the informativeness of the diagnosing parameters for a cylinder­piston group in the diesel engine during operation

Development of technical maintenance of transport means consists in providing their technical state at a significant level of functional operability for which the use of quality lubricants is a key requirement. Therefore, determination of technical state of truck transmission oils by the method of thermal-oxidative stability during their operation is an urgent problem. This problem was solved and technical state of the transmission oil was studied on the basis of operational tasks and the results of their chemotologic studies. These results can be used in development of a system of vehicle maintenance and when substantiating feasibility of using concrete oil grades during operation. A procedure for studying, determining state and compliance of the working oils by their thermal-oxidative stability with operating conditions during vehicle operation has been developed. State of transmission oils was studied during vehicle operation in gearboxes of KamAZ 6520 and MAN TGA 6×4 trucks. The study of working transmission oils was conducted at following parameters: light transmission, evaporability, viscosity. The results of studies of light transmission through an oil sample and evaporability after application of the temperature regimes used in testing working oils were used in graphical and analytical representation of the coefficient of thermal-oxidative stability. Variation of the coefficient of thermal-oxidative stability of oils of respective grades depending on their relative viscosity was determined. Analysis of the obtained functions will enable development of recommendations on conformity of working oils to the conditions of their operation. It was found that the Tedex Gear GL-4 80W90 transmission oil, used in MAN TGA 6×4 trucks, corresponds by its thermal-oxidative stability characteristics to the operating conditions. At the same time, the study of use of YUKO TО-4 80W-85 transmission oil in KamAZ 6520 trucks has shown that the oil did not demonstrate its functional capacity at runs of 8‒30 and 45 thousand kilometers. This was confirmed by analysis of the mathematical model of variation of thermal-oxidative stability of oils depending on relative viscosity, namely, by overshoot of some numerical values of the function beyond the level of 0.85 un. for the vehicle runs under study. It was established that the study data can be applied to substantiation of further operation and selection of transmission oils for the studied vehicle models in transportation activities of the enterprise

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Studying truck transmission oils using the method of thermal-oxidative stability during vehicle operation

Our research into the formation of a functional copper-containing surface layer on parts of automobile engines by using an alignment tribotechnology has established a decrease in the wear of parts during their operation. It was found that the formed coating creates an elastic layer that reduces strains in a material of engine parts. Our experimental study of the coercive force of parts' working surfaces has confirmed a decrease in the accumulation of destructive stresses in the near-surface layers of a components' material. In turn, a comparative analysis of the obtained results by using a coercimetric method confirms that the proposed aligning tribotechnology leads to reduction of the stressed-strained state and makes it possible to improve wear resistance and enhance the technical condition of diesel engine cylinder liners: the magnitude of coercive force reduces by 7.5 %, while operating time increases by 16 %. In this case, at larger operating time: 254.8 thousand km against 220.5 thousand km, according to data on the coercive force (14.2…9.1) A/cm and (13.2…9.0) А/cm, it is almost in the same condition.The functional surface layer forms when introducing a composite oil to the tribotechnology of cold alignment of an automobile powertrain. We have proposed and implemented a circuit to connect electric current to components at an engine's cylinder-piston group as a result of studying the developed tribotechnology of alignment. The features of this scheme are that the constant electric current is supplied by the plus polarity, through the brush-collector node, to the crankshaft, and by the minus polarity, through the clamping contact, to the crankcase block.The research results suggest a possibility to control the internal strains and the subsequent magnitude of wear in a material of working heavily-loaded components of automobile powertrains provided they are serviced properly. The proposed tribotechnology of alignment could be of interest for both service departments at trucking companies and for car service stations.

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Exploring a possibility to control the stressed­strained state of cylinder liners in diesel engines by the tribotechnology of alignment

We have conducted a selection of diagnostic parameters to control technical condition of the gear box. Development of technical operation of transportation vehicles is aimed at examining and predicting a technical condition with the formation of a rational diagnostic base being a key direction. Solving the tasks in a given scientific-technical field was based on the theory of relative sensitivity. This involved a theoretically substantiated relationship between diagnostic parameters and the indicators of reliability for the assemblies of transportation vehicles based on their parametric dependence that we proposed. The implementation of theoretical research was conducted by determining a technical condition based on the express diagnosis of transmission oil in the gear box of the family of trucks KamAZ. We have performed express control and examined the working transmission oil for the following parameters: alkaline number, the content of mechanical impurities, dielectric permittivity. The dependences of their change on the run of transportation vehicles were obtained, as well as the corresponding criteria of sensitivity over different intervals of the run. We selected diagnostic parameters and formed a rational base using the criterion of relative sensitivity, establishing the run and the required diagnostic parameters. Control over diagnostical parameters of the gear box should be executed for the following indicators: the content of mechanical impurities in transmission oil – within intervals of 0…12 and 48…60 thousand km of the run; the dielectric permittivity of oil should be controlled within 48…60 thousand km of the run; the alkaline number of transmission oil should be controlled within 12…24 and 48…60 thousand km of the run of the examined transportation vehicles. Based on the compiled rational diagnostic base, it is possible to run an analysis and predict technical condition of the gear box, as well as establish supporting operations in technical operation.

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Substantiation of diagnostic parameters for determining the technical condition of transmission assemblies in trucks

Increase of wear resistance of different types of tribomating which are functioning in fluid lubrication is possible due to: choosing more expensive and high quality material of samples that is not always sensible; applying some wear resistant coatings on them; selection and formation of complex composition of oil additives. Due to nanomaterials development there is a possibility of efficient use of functional additives such as geo modifiers in tribology. Due to geo modifier-based oil composites use it’s not necessary to make any structural changes of machines mated parts though their wear resistance is increased. It requires the conducting of some experimental tribological research. It was found that oil media modified by a geo modifier increase the wear resistance of working surfaces of different types of tribomating. The use of geo modifier КGМF-1 (Katerynivka friction geo modifier -1 (patent of Ukraine No69657)) has been suggested. Lubrication quality of oil compositions based on М-10Г2К (M-10G2K) (motor oil of 10th viscosity grade, of group Г2К (G2K), for the CIS countries the oil grade conforms SAE 30) + КGМF-1 (4.0 4.5%) has been studied on a computer modernized four-ball friction testing machine ЧШМ-К1 (CHMK-К1). To evaluate the lubrication quality of the oil composite with the suggested geo modifier and to use the comparative analysis of the obtained results the research was conducted on commercial samples of base oil M-10G2K and oil composites M-10G2K + XADO Maximum for Diesel Truck (2.0 2.3%) (agent 2D sliding revitalization factor (RF) 100, revitalizant 1 Stage RF 100, metal conditioner RF 5.5), M-10G2K + cuprum glycerate (3.7 4.5%). Some average indices of wear, critical load, and welding load have been found. Samples division into 4 types of mating according to the following characteristic features: mobility, material hardness and friction area has been suggested for more accurate picture of wear resistance changes of samples tribomating which are functioning in base and modified oil. Lower friction torque of different samples couplings in modified oil by geo modifier КGМF1 in comparison with base oil M-10G2K was recorded while using Friction machine 2070 SMT-1 with add-on module "ring-ring". The samples wear rate in modified oil by geo modifier КGМF-1 in comparison with base oil M10G2K was studied by method of acoustic signal amplitude measurements directly from the friction zone by a commercially produced instrument of Brüel & Kjear company. Corresponding author: V. Aulin Central Ukrainian National Technical University, 8 Universytetskyi ave., 25006 Kropyvnytskyi, Ukraine. E-mail: AulinVV@gmail.com R E SE A R C H V. Aulin et al., Tribology in Industry Vol. 41, No. 2 (2019) 156-165 157 It was found that efficiency increase of the oil compositions under investigation is taking place in the following order: M-10G2K + XADO Maximum for Diesel Truck, M-10G2K + cuprum glycerate, M-10G2K + КGМF-1. Wear index due to the use of modified oil M-10G2K + КGМF-1 was 19 20 % lower comparing to the obtained data of the base oil, critical load value was 27 29 % larger, and welding load – 24 25% larger respectively. Moreover, it was recorded that the maximum wear rate of samples in their functioning in modified oil M-10G2K + КGМF-1 was 3 times lower, and friction torque change law is similar to the wear rate change depending on the time of testing. © 2019 Published by Faculty of Engineering

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Wear resistance increase of samples tribomating in oil composite with geo modifier КGМF-1

Methodological approach to estimating the efficiency of the stock complex facing of transport and logistic centers in Ukraine

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A. Hrinkiv

Papers

Substantiation of diagnostic parameters for determining the technical condition of transmission assemblies in trucks

Wear resistance increase of samples tribomating in oil composite with geo modifier КGМF-1

Methodological approach to estimating the efficiency of the stock complex facing of transport and logistic centers in Ukraine

Improved tribotechnology of running-in