Balance and low-frequency vibration of two-cylinder two-shaft engines

Abstract

Introduction. One of the main requirements for piston engines of low and moderate power is their high balance, which conditions their low vibroactivity. The purpose of the study was to conduct a numerical analysis of the balance and low-frequency vibration of a two-cylinder two-shaft engine with a Neander Motors mechanism. A criterion based on the root-mean-square values of the vertical vibration displacements was used to determine the quantity of the imbalance and low-frequency vibration of this engine. Methodology and research methods. An engine solid-state spatial model with the Neander Motors mechanism, including a two-shaft conversion mechanism and body parts, was created in accordance with the numerical analysis method in the environment of the software product Autodesk Inventor Professional. The dynamics problems of the mechanical and mechatronic systems were solved with the automatic formation of links motion equations on the basis of the Lagrange equations followed by their numerical integration. Scientific novelty and results. The numerical results analysis of low-frequency vibration caused by unbalance and gas forces in a two-cylinder two-shaft diesel engine have been given according to the Neander scheme. Its advantages over two-cylinder engines with a crank mechanism were shown. The conclusion was drawn concerning the expediency of this scheme for low and moderate power engines. Practical significance. The analysis of the comparative data of the Neander 2ЧН 8/8 and КШМ 2ЧН 10,5/12,7 engines allowed to conclude that the Neander engine had a high balance and low vibroactivity, and therefore its further practical study seems reasonable, including its application in ground vehicles.