Adjusting Surface Integrity of Gears Using Wire EDM to Increase the Flank Load Carrying Capacity

High performance gears require high geometrical qualities. For these aspects expensive grinding processes are indispensable as finishing processes. This paper deals with the investigation of wire EDM (WEDM) as a technological substitution to grinding from part functionality point of view. Geometrical gear quality, surface integrity and load carrying capacity for WEDM and ground gears were analyzed and compared. No difference regarding gear shape was found for both processes. Residual stress and hardening profiles did not show significant differences. The topography features the process typical characteristics. Following, load carrying capacity of the tooth flank surfaces was investigated. The WEDM finished gears last three times longer than the ground gears due to a beneficial running-in topography formation with increased tribological characteristics.