Dynamic Modeling and Structural Angle Dynamic Characteristic Analysis of a Non-Circular Planetary Gear Train

This study investigates the dynamic response of non-circular gear planetary trains in transplanting mechanisms, focusing on variable transmission effects. A time-varying mesh stiffness model was developed for non-circular gears using pitch curve parameters, incorporating pressure angle, contract ratio, and equivalent teeth number as dynamic variables. A dynamic model of the planetary gear train was established to analyze component vibration characteristics. Comparative analysis reveals that non-circular gears’ variable-speed transmission significantly amplifies gear train vibrations compared to that of circular gears. Structural angle effects were examined, demonstrating the structural angle’s critical role in modulating vibration energy distribution between sun and planet gears. Frequency-domain analysis identified optimal structural angle ranges that minimize resonance risks by controlling component center vibrations. This work clarifies the coupling mechanisms between geometric parameters and transmission characteristics in non-circular gear systems. A design criterion based on frequency–energy distribution is proposed to optimize high-speed transplanting mechanisms. These findings advance the understanding of vibration modulation in variable-ratio gear trains and provide theoretical guidance for enhancing operational stability in agricultural machinery.