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The work is aimed at increasing the reliability, accuracy, information content and depth of the process of diagnosing the cylinder-piston engine group. For this, an automated diagnostic system has been developed, which includes a system unit with a monitor, special software for measuring and processing information, a measuring analog-to-digital module, adapters for connecting to the engine. The diagnostic system allows you to record the change in pressure of the cylinder for every degree of rotation of the crankshaft with an error that does not exceed 1.7%. Measurements are performed in test mode, when the crankshaft of the engine is scrolled with a starter, and strain gauges are screwed in place of spark plugs. The measurement results are presented in the form of diagrams, text and digital values. The system also allows you to save, reproduce and transmit diagnostic information in digital, graphic and text form.

This paper describes research focused upon improved the quality of automobile engine quality. Methods and models were developed for estimating and predicting the technical condition of internal combustion engine (ICE), which provides usage of the decision support making in the search for minimum fuel consumption regimes. We developed models of multi-criterion, multiparametric optimization of energy and material-material characteristics of ICE according to the system approach. The developed methods and models for estimating and predicting the technical state of the functionally interconnected and interacting ICE components are performed taking into account their hierarchy and topologies, energy resource used and the fuel. The cognitive methodology has been used to make engine models researches and analysis. The paper focuses on the fuzzy logic approach applying, considering the indeterminacy, incompleteness and unclear information in the engines operation processes.

Problems of reducing emissions of harmful substances and fuel consumption of the engine are interrelated, since they are mainly determined by the work process. Measures aimed to reducing fuel consumption cause changes, often upwards, toxic compound formation. The fuel and environmental criterion is proposed taking into account the engine operating conditions for a reasonable choice of technical solutions for the comprehensive improvement of fuel economy and toxic level indicators of the exhaust gases. This criterion allows assessing the effectiveness of solutions to improve combustion efficiency, the use of alternative fuels, exhaust gas aftertreatment systems, and other measures.

The bulk of automobiles are equipped with ABS currently. Having of automatic devices that prevent vehicle wheels from locking and skidding does not require consideration of the normal reactions on the front and rear vehicle axles wheels’ changes dynamics. However, ABS malfunction is possible for various reasons, and in this case the braking system must provide the safety vehicle braking. To provide this, it is necessary to return to the problem of choosing the rational braking forces distribution between the wheels of the front and rear axles.

Plane bearings are used as rotating bearings for gear wheels of vehicles transmissions. The design of these units provides for the operation of bearings in two main loading modes: sliding mode (without load transfer) and rolling mode with slipping motion (with load transfer). The mode of sliding bearings operation in the rolling and slipping mode is not sufficiently studied, which makes it impossible to quantify at the design stage the influence of the operating conditions of the vehicle on wear processes, and, therefore, on their reliability. It is necessary to take into account the fact that the condition of the bearing coupling affects the conditions of the gearing. The results of statistical studies of wear and accelerated wearing tests of sliding bearings of gears of a wheeled tractor show the low reliability values of both gear wheels and sliding bearings.

In the design of gearboxes and transfer boxes of heavy-duty vehicle`s transmissions, sliding bearings are often used as supports for gear wheels. Analysis of the results of statistical processing of gearbox parts failures and transfer boxes of wheeled tractors with a pulling force of 30 kN indicates the need to improve the reliability of the sliding bearings of the gear wheels. Such plain bearings ensure free rotation of the gear wheels in case of the torque transmission absence, and when locked by a clutch, the radial load of the gear wheel is sensed, while operating in the slipping rolling mode. Such units are poorly understood and in the technical literature sources there are no recommendations for their engineering, which often leads to errors when selecting operation gaps and press fitted in gear wheels. The manufacturers of the transmissions assemblies replaced the plain bearings, which in this case are made of metal-ceramic bushes, for roller bearings.

In connection with the tightening of environmental standards, the leading manufacturers of marine low-speed engines are carrying out intensive work on their conversion to gas fuels. Due to the design features in this class of engines, only internal mixture formation is possible. For the organization of which two different approaches are possible. To date, only two are currently implemented. MAN started production of engines with gas fuel supply to the working cylinder under high pressure at the end of the compression stroke, and WinGD under low pressure at the beginning of the compression stroke. The analysis, performed by the authors, showed, that increasing the pressure before the gas supplying mechanisms to 3.5...6.0 MPa can reduce the residence time of the gas-air mixture in the working cylinder and reduce the likelihood of detonation combustion.