Utilization of Synchronous Averaging for Inspection of Tooth Surface Undulations on Gears (Localization of Nonmesh Harmonic Components to Individual Gear)

Cyclic undulation of the gear tooth surface is one of the important sources of gear noise and vibration. It has been known that vibration caused by this source can appear at the nonmesh harmonic frequency components (ghost components). As there are no relationships between the frequency of this vibration and any gear specifications, the gear noise source is hard to detect. This paper proposes the utilization of the synchronous averaging technique for diagnosis of the source of nonmesh harmonic vibration components on a gear pair, and shows the possibility of using this technique for inspection of tooth surface undulation. The method for practically applying this technique is discussed in detail. Results demonstrated in the form of spectrum showed good agreement with the undulation assessed from precise tooth surface measurement over the whole surface of every tooth. The effect of the direction of the arrangement of cyclic undulation on tooth surface and gear vibration is also discussed in this paper. Finally the limitation to the synchronous averaging technique was discussed with respect to gear ratio.