Mechanism and performance of a passive auxiliary steering device for low-floor light rail vehicle

Abstract

For low-floor light rail vehicles, a passive auxiliary steering device (ASD) is developed aiming at relieving the independently rotating wheelset (IRW) excessive wear and improving IRW bogie system running safety on curve line. The ASD can be briefly seen as some longitudinal springs arranged between a carbody with IRW and a carbody ahead or behind it to increase the vehicle horizontal flexural stiffness. Consequently, the vehicle will possess the characteristics of both single-type vehicle and traditional vehicle. When passing curved track, the yaw angle between the adjacent carbodies deforms the springs to generate moment which will reduce the unbalanced centrifugal force of the carbody with IRW. As a result, the centering ability of the IRW bogie is improved. The vehicle-track coupled dynamics model for a 6-module single-type low-floor light rail vehicle is developed and the simulations of vehicle passing through tangent and curve lines with and without ASD are carried out. The results indicate that the ASD can improve the IRW restoring capability on tangent track and the IRW negotiation performance on medium and large curved tracks. Besides, larger spring preload, larger steering stiffness and smaller steering clearance are preferred to guarantee the higher performance of this ASD.