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EN
The mathematical model for calculating the response time of the compression ratio of the mechanism for compression ratio changing (MCRC) is presented in this article. This revealed the influence of various engine factors with the connecting rod and crank mechanism (CRCM) on the operation of the MCRC (for example, the rate of the compression ratio change). The results of the study of the operation of the MCRC indicate a strong influence of the values  (relative area of flow passage of channels) and р (pressure) on the response time τ in the field of their small values. This indicates that with insignificant changes of the area of flow passage of channel of the hydraulic lock and the minute oil pressure in the cavities, a significant response rate of the MCRC is ensured. The results demonstrate the possibility of speedy compression ratio change in the engine with the MCRC. Calculation studies showed that the mechanism full operation occurs quickly (0.02 s per unit εx), which indicates the expediency of using such a high-pressure pump in a four-stroke gasoline engine with CRCM. The mechanism movable body complete movement (S = 4 mm) at the oil temperature in the hydraulic system of 45°C and pressure on the body of p = 60 bar are stated to occur for 0.2 s.
EN
To estimate the effect of the axial movement of piston rings in the piston grooves on the blow-by in the internal combustion engine (ICE) by an experiment- calculated method. This contributes to the development of practical recommendations for the further improvement of the engine ring seal designs. Abstract theorems were used when modelling the effect of the axial movement of piston rings in the piston grooves on the blow-by in an ICE. They are based on the fundamental theory of heat engines, thermodynamics and hydraulics. The ICE running was analysed using design-theoretical research methods. The effect of the axial movement of piston rings in the piston grooves on the blow-by in the ICE was established. This creates prerequisites for a more accurate assessment of their sealing capacity and for ways to further improve them. Calculated dependences for computing the blow-by depending on the positional relationship of the rings in the piston grooves were obtained. The dependences of gas escapes on the engine crankshaft speed were obtained, which is especially important for idling modes by which one can judge the dynamic stability of the ring seal and solve the problems of improving its service properties. The calculated dependences for evaluation of the blow-by depending on the positional relationship of the rings in the piston grooves and their respective possible gas flows in the ring seal were obtained for the first time. The practical method for estimating the dynamic stability of the ring seal by decencies of gas escape on the crankshaft rotation speed in ICE was proposed.
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