Optimization-based dynamic modeling considering thread and gear coupled mesh stiffness and vibration analysis of planetary roller screw mechanism

The planetary roller screw mechanism (PRSM), as an efficient and precise transmission device, is a transmission component with coupled motion of thread and gear. Due to the complex meshing relationships, the mesh stiffness between the different components and the dynamic responses of each component remains unclear. In this paper, based on the energy method, the mesh stiffness of the thread, gear, and their coupling is calculated. Then, by considering the meshing error, a coupled dynamic model including the thread drive and gear drive is established using the lumped mass method. For uncertain parameters in the model, such as supporting stiffness and supporting damping, parameter optimization is performed using the particle swarm optimization (PSO) with experimental data as a reference, and the contribution coefficients of each component on the overall vibration are analyzed. Subsequently, the dynamic model is solved with the optimized parameters, and the effectiveness of the coupling dynamic model is verified through experimental data under different operating conditions. Finally, the vibration responses of each component are analyzed in detail, revealing their impact on the system's dynamic behavior, which can provide references for structural optimization design. Overall, by accurately calculating the mesh stiffness between different components of PRSM, an accurate dynamic model is obtained using optimization algorithms and experimental data. This model offers critical insights for designing and manufacturing high-performance PRSM, enabling effective vibration reduction and facilitating fault diagnosis.