Механика машин, механизмов и материалов (Sep 2022)
Method for Assessing the Modal Parameters of Planetary Reducers of Mining Dump Trucks Motor Wheels during their Operational Vibration Diagnostics
Abstract
Technical condition diagnostics of the planetary reducers of motor wheels in mining dump trucks electromechanical power units requires the study of dynamic processes caused by shock pulses in gearings when tooth remating. The levels of the occurring vibrations are determined by the natural frequencies and natural modes of reducer. The article describes calculation method based on the study of the developed dynamic model of a two-row planetary reducer of a motor wheel, describing the torsional vibrations of its elements and differing from the known ones by taking into account the compound motion of the planetary row satellites, the axes of which rotate together with the carrier. The calculation of natural frequencies and modes of vibrations is reduced to the computation of eigenvalues and eigenvectors of a matrix of special form based on the application of the iterative numerical method of Jacobi rotations. As an example, the calculation is given for gears of the motor wheel reducer of BELAZ mining dump trucks of the 7530 and 7531 series with a load capacity of 220 and 240 tons, respectively. The calculation of the natural frequencies of reducer performed makes it possible to determine those harmonic components of vibration-inducing disturbances in the form of shock pulses which cause resonance phenomena in the mechanism contributing to a significant increase of dynamic loads levels and accelerating the processes of lifetime expense of gear trains. In addition, the analysis of natural modes parameters makes it possible to determine the reducer elements with the highest vibration activity and monitor during vibration monitoring the technical condition of gear trains that limit the reliability of the mechanism.
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