A novel low-stiffness blade gear for micro-vibration isolation: Design, modeling, and verification

The space pointing mechanism serves as a critical component along with high-precision pointing, positioning, and stable tracking, which has been widely used in space payloads such as antennas. Micro-vibrations, stemming from internal defects within the mechanism or external disturbances, can significantly disrupt the normal operation. Therefore, isolating micro-vibrations is of great importance for high-precision space payloads. This paper proposes a novel low-stiffness gear with replaceable blades, which could effectively isolate micro-vibrations owing to its inherent low-stiffness characteristics. Using the second-order deformation theory of cantilever beams, a nonlinear transmission stiffness model of the low-stiffness gear and the vibration transmission model of the system were established, which could be applied even when the blade undergoes significant deformation. We constructed experimental setups for testing the static loading characteristics of the gear, and evaluating its vibration isolation performance. A static loading device was built, and the transmission stiffness model was verified through static testing. Based on the equivalent criterion of rotational stiffness and vibration transmissibility, a ground equivalent test method was proposed and a ground test device for isolation performance was established. Multiple sets of isolation performance revealed that the design method of the low-stiffness gear was reasonable, which exhibited the predictable and positive capabilities of vibration isolation when integrated into the target Solar Array Drive Assembly. This study provides quantifiable guidance for the parametric design and optimization of the low-stiffness gear.