Mechanism of track random irregularity affecting dynamic characteristics of rack vehicle

The track random irregularity not only worsens the running stability and smoothness of the rack vehicle, but increases the vibration and impact of the gear-rack system. To reduce the influence of track random irregularity on the dynamic characteristics of rack vehicle, the sensitivity of rack vehicle to track irregularity is studied based on the rack vehicle-track(rack)-coupled dynamic model (RVTM). Firstly, the effectiveness and accuracy of RVTM are verified through engineering tests. Then, according to the generation principle of track irregularity, the influence mechanism of irregularity on the dynamic meshing behavior of gear-rack system is analyzed. The results show that the track random irregularity has a great influence on the vibration of the rack vehicle. The vibration of the rack vehicle mainly comes from the track random irregularity. The vertical and longitudinal vibration of the gear-rack system is less affected by the irregularity excitation, while the lateral vibration is significantly affected. The gear-rack system is less sensitive to irregularity I (vertical irregularity and roll irregularity) and has a strong response to irregularity II (lateral irregularity and gauge irregularity). Therefore, it is suggested to improve the stability of the gear-rack system by reducing the track irregularity II to ensure the safe and smooth operation of the rack vehicle. RVTM is validated in this paper, which can be effectively used in the dynamics research of rack railway and optimizes the running performance of rack vehicle. The research on the dynamic response of the rack vehicle to the track irregularity provides an important theoretical basis for improving the stability of the rack vehicle and can provide a reference for the design and evaluation of the rack railway.