Rotational Vibration Response of Power Transmission Systems

The main goal of monitoring systems for rotary machinery is to provide sufficient time between warning and failure of machine elements so that safety procedures can be implemented. The present study investigates the dynamics of transmission systems by interpreting the interaction dynamic loads of the elements of the system. This phase of the effort concerns itself with the determination of the relationship of the dynamic tooth loads to the crack size of a single cracked tooth of a spur gear pair. A mathematical model of the test rig used for the general study is proposed. In addition to accounting for the time-varying stiffness of the meshing tooth pair, the model also includes gear errors and damping. A Newmark-Beta numerical integration scheme is used to solve the system of non-linear coupled equations. Results for the dynamic tooth loads as a function of crack size are presented for a wide range of rotational speeds. Simulated and experimental vibrational signals are also presented.