The National Transport University Bulletin

Abstract

This article depics the mobile continuous earth-moving machine dynamic model with a chain-type trenching equipment in order to determine the effect of changes in the elastic-inertial system parameters on its own resonant frequencies. The object of the research: natural resonant transmission frequencies of the soil-working working equipment drive in the mobile earth-moving continuous action machine with a chain-beam working body. The purpose of the work: to determine the system elements, in which the elastic-inertial parameters affect the lower natural resonant frequencies. To give practical recommendations on the parameter choice of such elements in order to deviate from the resonant frequency. Creation of strong, reliable and durable machines depends on the dynamic load accuracy and ways to reduce it. Modern earthmoving machine structure formation can be realized using the modular principle, but always with taking into account the full picture of possible machine loads and their drives in the process, these load magnitude and their dynamic characteristics. In accordance with the dynamic synthesis conditions, the dynamic system machine parameters should be selected so that the external load machine change frequency in its maximum productivity mode doesn’t coincide with the dynamic system natural frequency. According to the theoretical and strain gauge research results, it is established that the frequency of the first form of earth-moving machine drive torsional oscillations is close to 9 Hz. The first frequency oscillation shape has a node between the gearbox masses, which can lead to fatigue shaft destruction, joints or gears of the base tractor transmission part destruction. The frequency of the natural oscillation system is close to the traction chain link engagement frequency with the sprocket teeth in the earth-moving machine maximum productivity mode. The study results of the inertia mass change moments and the connection stiffness indicate that the system first natural frequency is influenced by the engine mass parameters, the machine unloading device and the engine damper elastic parameters, base chassis cardan gears. The machine parameter change leads to the first natural frequency change by 5 – 20%.

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