Radial adjustment mechanism of a newly designed coupled-bogie for the straddle-type monorail vehicle

Abstract

ABSTRACT The bogies of the Hitachi and Bombardier straddle-type monorail vehicles could not be in the radial state on the circular curve because of the constraints of their own structure or secondary suspension system. Therefore, a large load always existed on the guiding wheels, restricting the curve negotiation speed of the vehicle. Taking this as the starting point, this study aimed to propose a newly designed bogie, called the automatic radial coupled-bogie (ARC-bogie). The theoretical model of linear steady-state curve negotiation of the ARC-bogie was established to analyse the passive radial adjustment mechanism of the ARC-bogie, and the calculation method for the optimal coupled parameters required for achieving the radial state was proposed. To validate the theoretical model, the dynamic performance of the ARC-bogie and the influence of coupled parameters were analysed by dynamic simulation. The result showed that the coupled rotary stiffness could make the ARC-bogie achieve the radial state automatically on the circular curve under reasonable matching between the secondary suspension system and the coupling mechanism. Moreover, the maximum radial force of the guiding wheels decreased obviously, and the curve negotiation safety of the vehicle improved remarkably. Finally, a scheme for the coupling mechanism of ARC-bogie was proposed.