Synergistic vibration control in heavy-duty helical gear systems through gravity compensation and coupled SCES-SFD dynamics

Heavy-duty helical gears in high-power transmission systems face critical vibration challenges arising from thin-walled web designs for enhancing power density. This study proposes a hybrid vibration control strategy integrating a squirrel cage elastic support (SCES) and squeeze film damper (SFD). A dynamic modeling framework employs quadratic hexahedral elements for flexible gear shafts and quadratic tetrahedral elements for efficient SCES parametric analysis. Component mode synthesis (CMS) is used to balance computational efficiency and accuracy, while nonlinear oil-film forces of the SFD are calculated via the finite difference method. The model is validated through SCES modal testing (errors <4 %) and system-level finite element analysis of deformations, stresses, and modal characteristics. Key findings reveal that the SCES effectively regulates shaft-related vibrations without altering web-dominated high-order modes, reducing the 7th-order umbrella mode frequency by 5.5 %. Gravity-induced eccentricity degrades SFD damping performance, which is mitigated by a pre-offset SCES configuration that reduces SCES dynamic stresses by 5.4 % and maintains vibration suppression under gravitational loads. This methodology establishes a systematic framework for optimizing the structural-dynamic performance of heavy-duty gear systems, enhancing durability and operational stability.