Time-varying transient EHL behaviors of spur gear pairs considering tooth waviness extracted by gaussian filter

Tooth waviness has been experimentally proven to be the main cause of “ghost order” noise in high-speed gear transmission systems, which affects vibration and noise through meshing contact or transmission errors. However, most studies have focused on the influence of tooth surface roughness on the gear lubrication contact characteristics, ignoring the effects of mesoscopic tooth waviness. Furthermore, there is a lack of an effective method for extracting tooth waviness from measured tooth topographies. To fill this gap, a novel method for extracting tooth waviness based on the Gaussian filter is proposed. A three-dimensional transient line contact elastohydrodynamic lubrication (EHL) model coupling rolling, sliding, and elastic deformation is established. The effects of tooth waviness and its parameters on the lubrication characteristics and contact mechanical properties are analyzed. Results show that tooth waviness alters the overall stability of the gear meshing lubrication regime. Compared to smooth tooth surface, waviness has a more significant effect on rolling friction than on sliding friction and film damping. The effects of waviness order and amplitude on the tooth meshing contact mechanical properties exhibit opposite trends. This research establishes a theoretical foundation for understanding the dynamic service behavior under the influence of tooth waviness and holds significant guidance and engineering value for controlling the tooth surface machining quality.