Additive manufactured and topology optimized flexpin for planetary gears

This paper shows how the interdisciplinary use of additive manufacturing (AM) and topology optimization (TO) lead to a better load distribution and a related increase in performance within a planetary gearbox. For this, it has been investigated how to use TO for designing the flexible support of the planets pin and to reduce thereby the load sharing factor (Kγ). 18 digital experiments were performed to evaluate the best setting for this TO. A completely new shape for a “flexpin” design was found which offers significant advantages in terms of compliance and misalignment for the flexible support structure of planet gears. Because of AM, the focus can stay on the main function of the flexpin including the component reduction. Critical interfaces are no longer necessary. This allows a much better definition of the compliance, an improved assembling, and a safer operation. The best TO-design concept was selected and edited for additive manufacturing. The final validation by FEM showed an increase in load capacity by 13% and an additional reduction of the misalignment of 77%