Method for estimating vibration responses of belt drive systems with a nonlinear tensioner

A friction-type tensioner is widely used in a belt drive system for maintaining belt tension constantly and reducing vibration. Owing to friction dampings, the curve of the reaction torque and the imposed angle of tensioner arm is a hysteretic loop. Here, the hysteretic behavior of tensioner is considered in dynamic analysis of a belt drive system. A hysteretic model for describing the applied torque versus the imposed angle of tensioner arm is established. And an iterative algorithm is proposed for estimating the nonlinear equivalent viscous damping of tensioner under a varying excitation frequency. A timing belt drive system is taken as an example. Based on the existing research, the dynamic models for a belt, an automatic tensioner and rotational pulleys of system are also given. The vibration responses of a belt system, such as the oscillation angle of tensioner arm, the transmission error between pulleys and the hub load applied on pulley, are calculated and compared with the measurements, which are validated the presented method. The influence of damping ratio of tensioner on dynamic responses of system is investigated, and the influence of iteration parameters on the iterative efficiency is discussed. The presented method is beneficial to modifying the existing method for calculating the vibration responses of a belt drive system.