Influence of yaw dampers on vertical vibration of railway car body induced by wheels rotation and its countermeasures

Abstract

Vertical vibrations in railway vehicles are not only induced by track irregularity but also affected by the rotation of wheelsets with small mass imbalance. It is known that the excitation force generated by the rotation of wheelsets is transmitted from bogies to car bodies through longitudinal connecting members such as traction devices and yaw dampers. In this research, we first investigated the influence of yaw dampers on the vertical car body vibration induced by the rotation of wheelsets. Roller rigs rotation tests were performed using a full-scale vehicle with/without yaw dampers. In cases where there was no yaw damper, the vertical vibration of the car body was lower than that of cases where yaw dampers were equipped. This result indicates that vibration transmissibility from bogies to car bodies via yaw dampers should be reduced. In order to suppress this vibration transmission, we developed two vibration reduction devices: a new mounting structure for yaw dampers having a moving beam, and displacement-dependent rubber bushes for yaw dampers. The results of roller rigs rotation tests show that the developed devices reduced the car-body vertical vibrations caused by the excitation forces via yaw dampers. Moreover, we conducted running tests on a commercial track, and the results show that the vertical car body vibrations were reduced by applying displacement-dependent rubber bushes for yaw dampers.

Keywords

• railway
• yaw damper
• vibration of car body
• forced vibration
• vibration isolation
• ride comfort