Radial cylinder four-stroke moderate power engine

Introduction. Radial cylinder engines have satisfactory mass-dimensional characteristics, though the use of a crank drive transducer mechanism (CDTM) with trailed connecting rods complicates the design significantly. Residual unbalance of vibroactivity caused by the use of crankshafts with hook-on connecting rods in radial cylinder engines is possible to eliminate by the application of the ship Pancake engine design. The purpose of the study was to analyze: links loading of the mechanism similar to the Pancake engine design by forces corresponding to a four-cycle cycle; stress-strain state of the connecting rods clips and crank heads; the engine balance and vibroactivity. Methodology and research methods. To carry out a computational research, a solid-state engine model was created in the Autodesk Inventor Pro software product environment. During the simulation of the crankshaft movement and its operating under the gas forces action, vibration displacement, vibration velocity and vibration acceleration of the engine mounts were determined. The finite element method was applied to study the stress-strain condition. Scientific novelty and results. The specialists of FSUE “NAMI” have developed projects of engines with spark ignition 3Ч 3.9 / 3 and 3Ч 7.6 / 5 on the basis of the same trimmer dimension serial parts of a single-cylinder four-stroke engine. Mass inertial characteristics of the links were defined. The values of specific pressures on the necks and bearings did not exceed those for engines with a conventional crank. Dimensions and shape of counterweights allowed to locate the center of the system mass “Crankshaft -connecting rod bearing - crank connecting rod masses - holders” on the axis of the rotation shaft. As a result of it the centrifugal force developed by these masses was not transmitted to the main bearings. It was established that the Pancake design scheme could be successfully used in four-stroke engines with modern boost levels. Practical significance. The developed three-cylinder engines can be of practical interest for light-engine aircraft, mobile electric generators, motor-compressors, combined power plants for road transport and other devices (including special-purpose ones).

crank mechanism, star-shaped engine, steadiness, stress-strain state

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