A Newly Designed Coupled-Bogie for the Straddle-Type Monorail Vehicle: Calculation Method for the Key Parameter and Dynamic Performance

This study aimed to propose a newly designed bogie, called the automatic radial coupled-bogie (ARC-bogie) that could achieve the radial state automatically on the circular curve. Rotary stiffness was set between the two adjacent single-axle bogies beneath two adjacent car bodies, and the two bogies were coupled as the new type of articulated bogie. The theoretical model of linear steady-state curve negotiation of the ARC-bogie was established to analyze the passive radial adjustment mechanism of the ARC-bogie, and the calculation method for the optimal coupling parameter required for achieving the radial state was proposed. To validate the theoretical model, a dynamic model of the straddle-type monorail vehicle equipped with ARC-bogies was established. The dynamic performance of the ARC-bogie was simulated and analyzed. The result showed that the ARC-bogie could 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. The adaptability of the ARC-bogie to the surplus/deficient superelevation was quite good. Finally, a scheme for the coupling mechanism of ARC-bogie was proposed.