Elastohydrodynamic film thickness and acoustic emission for meshing of spur and helical gears

This paper presents experimental evidence of the correlation between Acoustic Emission (AE) activity and the specific film thickness (lambda) for operational spur and helical gears. Whilst recording AE activity for a range of test conditions the specific film thickness was varied during operation by spraying liquid nitrogen onto the rotating gear wheel. It was noted that the AE activity reduced significantly as the theoretically estimated specific film thickness increased. It is concluded that the measurements of AE activity may offer an opportunity to quantify the level of asperity contact for meshing gears under a range of operating conditions.