Special-shape ring dampers for thin-walled gears subjected to traveling-wave vibration

•A complete design methodology is developed for the novel special-shape ring damper.•The damper can effectively suppress traveling wave vibrations of thin-walled gears.•The damper can get the desired contact pressure by designing its shape.•The damper has superior contact performance, contacting gears fully and uniformly.•The high-speed transmission experiments support the proposed method. Ring dampers are solutions to the traveling-wave vibration (TWV), a threat to high-speed thin-walled gears. But a complete design method for them is lacking, and normal dampers have contact problems, which make TWV mitigation less effective. So, a novel design method is proposed for the special-shape ring damper (SSRD), which is an improved type that aims to have good energy dissipation and contact performance. The methodology starts by estimating the optimal contact pressure, which acts on the SSRD to achieve the maximum frictional dissipation. Then its deformation is calculated based on the stress function method to get the shape that can perform the desired pressure. Furthermore, high-speed experiments are made to validate the TWV attenuation of the experimental SSRD. And its contact features are investigated by light transmission tests and finite element models. The results show that the SSRD can maintain almost complete contact with the gear, avoiding energy dissipation loss due to uncontacted parts. It also makes the contact pressure more even, which fits better with the uniform pressure assumption in the design methodology. Moreover, the SSRD effectively suppresses the TWV, and after damper installation, the strain peak reduction for the experimental gear exceeds 67.5%. The proposed methodology provides a theoretical basis for the ring damper design, and can be applied to ensure safe operation of aero-engine gears by suppressing their harmful dynamics behavior, TWV. [Display omitted]