Selection of fundamental period components of vibration modeling for non-faulty planetary gearboxes

Planetary gearboxes are `hearts' of transmission train among heavy industrials. The health condition of planetary gearboxes is the key to maintain reliable operation of industrial and promote harmonious social development. Frequency spectrum analysis of vibration measurements is a popular way for condition assessing. As prior guidance for spectrum analyzing, phenomenological modeling emerges as a simple and effective mathematical description of the vibration measurements referring to the sensor. A reasonable model of a non-faulty planetary gearbox is the essential work, either in understanding the motion behavior, or in condition monitoring and even for fault diagnosis. In this paper, traditional models are reexamined and investigated: we found the contradicting results from two classical references on the selection of fundamental period components when constructing models. The rationality of the traditional models is mathematically and experimentally studied, the more reasonable one is indicated.