Keywords: automatic tensioner, dynamic characteristics, experimental analysis, modelling, hysteresis, pulley–belt drive systems, dynamic stiffness, loss angle, pre–torque, excitation amplitude, excitation frequency, spring stiffness, damping coefficient, moment of inertia, tensioner arm, torque, angular displacement, least–squares method
Experimental and modelling analysis of dynamic characteristic for automatic tensioner in a two pulley–belt drive system
Experimental methods and parameters to evaluate the dynamic performances of an automatic tensioner in engine front end accessory drive (FEAD) system are discussed. The dynamic performances of a tensioner include dynamic stiffness and loss angle. The influences of the pre–torque, excitation amplitude and excitation frequency on the dynamic characteristics of tensioner are measured and investigated. Considering the pre–torque, spring stiffness and damping coefficient of tensioner, and the moment of inertia for the tensioner arm, a hysteretic model used for modelling the relations between the torque and angular displacement of a tensioner is proposed. Parameters of the model are identified using least–squares method. Then, a two pulley–belt drive system with two pulleys, a tensioner and a serpentine belt is taken as an example to demonstrate the proposed models. The dynamical properties of a tensioner, and the rotational vibrations of driven pulley and tensioner arm for the drive system are calculated and compared well with experimental data, which validates the presented hysteretic model.