Dynamic characteristics of a high-speed shaft-bearing-helical gear transmission system based on full-degree-of-freedom dynamics

To accurately evaluate the dynamic characteristics of helical gear transmission systems under high-speed operating conditions and to address the problem that the lumped parameter model fails to accurately reflect the system’s dynamic performance because its degrees of freedom are imperfectly considered, the full-degree-of-freedom dynamic model of the high-speed shaft-bearing-helical gear transmission system was established. The system’s dynamic equations were derived, and the natural frequencies calculated from the theoretical model, as well as the corresponding mode shapes for each degree of freedom, were compared with the finite element model simulation results. The relationship between the critical rotational speed within the system’s 3 × 104 rpm range of rotational speed and the system frequency was analyzed. The dynamic characteristics of the driving wheel and driven wheel in terms of amplitude and motion trajectory were investigated, and the influence of eccentricity on these characteristics was discussed. Results indicate that the relative deviation of the first six natural frequencies between the proposed model and finite element model ranges from 0.09 % to 13.1 %, and the deviations of the higher-order modes are within 1 %. This effectively validates that the full-degree-of-freedom model can accurately reflect the dynamic characteristics of the system, providing a theoretical basis for the design of high-speed-helical gear transmission system.