One of the most important factors in a belt driving system is tension acting on the belt because it affects significantly the life of the belt as well as the efficiency and quality of power transmission. The tension in a flexible belt consists of both static and dynamic components, meaning that it contains every information of the state of power transmission. The static component corresponds to the steady state power transmission while noncircularity or eccentricity of the pulley system, surface irregularity of belt and pulley, dynamic loading, etc. are responsible for the dynamic component. For the purpose of quality control of belt driving systems, so far only the static tension has been used. But, because the dynamic component contains useful information of the total system as mentioned above, it would be very beneficial for the quality control and diagnosis of the overall system to have a handy tool which can provide both of the static and dynamic components of the tension.
A method of identifying both components of the tension under operating conditions is introduced in this work. The method is based on the analysis of the transverse vibrations of axially moving belt under the condition of time varying tension. Frequency characteristics of the transient vibrations of the belt caused by an impact on it are analyzed and related to the static and dynamic components of the tension. Therefrom appropriate parameters representing the overall quality of the belt driving systems is proposed. The method is confirmed by comparing the tension identified by the proposed procedure with the actual measurements of the tension.