Modeling, calculation, and analysis of torsional vibration characteristics of the hydrodynamic transmission system in engineering vehicle

Abstract

According to the typical working conditions of a loader and considering the complexity of the working conditions, the hydrodynamic transmission powertrain system was modeled in this study. Because the hydrodynamic torque converter is a flexible fluid transmission component in the transmission system, this study proposes and establishes equivalent variable damping and equivalent variable stiffness models of the hydrodynamic torque converter. Based on this, a torsional vibration simulation model of the loader with variable damping and stiffness is proposed, and the frequencies and amplitudes of the torsional resonance modes of the transmission system varying with engine speed and hydrodynamic torque converter speed ratio are obtained. It is determined that the variable stiffness of the hydrodynamic torque converter has little effect on the natural frequency of the vehicle, and taking variable damping and stiffness as input, the natural frequency and resonance points of the transmission system can be calculated more accurately. The simulation modeling and calculation approach are experimentally verified, and the simulation results are valid and closer to the real resonance.