Damage mechanisms and tooth flank load capacity of oil-lubricated peek gears

Plastic gears are increasingly being utilized in higher performance ranges. Operating under oil lubrication can reduce friction and heat input. By running under oil-lubricated conditions, tooth damage such as abrasive wear recedes into a secondary role, and fatigue damage such as pitting becomes relevant for the durability of the gears. Polyether ether ketone (PEEK) is suitable for use in demanding operating conditions due to its very high strength properties, even at higher temperatures. In this work, the stress conditions affecting the tooth flank and the damage behavior of oil-lubricated PEEK gears are investigated and tooth flank strength parameters were determined for different temperature levels. Theoretical studies on the stress distribution on the tooth flank show the necessity to apply adapted profile modifications in order to reduce undesired stress conditions in the extended meshing area. In experimental investigations, the damage behavior of oil-lubricated PEEK gears is examined and the influence of temperature on the gear load capacity is discussed.