Anti-impact performance of an STF-based shock absorber with countersink damping holes for gearbox

Shear thickening fluid (STF) is a non-Newtonian fluid known for its exceptional impact resistance and energy absorption capabilities. In this study, an STF-based shock absorber with countersink damping holes was developed to enhance the energy absorption capacity of shock absorber under impact. Initially, the viscous medium of the shock absorber was characterized through microstructure and rheological property analyses. Furthermore, the energy absorption mechanism of an STF-based shock absorber was investigated by the compressive and impact experimental study. The impact energy was absorbed and dissipated by the STF itself and the friction between STF and damping holes of the piston. Finally, the developed STF-based shock absorbers were applied to the impact isolation of the gearbox, and their isolation effectiveness was verified by drop-weight impact tests. The results demonstrated that the maximum isolating efficiency of STF-based shock absorber against impact loads on a gearbox could reach 86%, exhibiting outstanding impact resistance performance. This remarkable efficiency underscores the promising potential for improving impact isolation in gearbox gear systems.