PERFORMANCE OF RAIL VEHICLES WITH INDEPENDENTLY ROTATING WHEELS

Abstract

A conventional railway wheelset is comprised of two coned/profiled wheels rigidly connected to a common axle. The solid axle wheelset has been successfully used for many years, principally because it has the ability of natural (self) curving and centering. But the conventional wheelset suffers from "hunting". The existence of wheelset hunting is due to the coupling present between the lateral and yaw motion of the rigid axle. By using independently rotating wheelset the constraint on the rotational motion of the two wheels is removed and the wheels are decoupled from the wheelset to enable them rotate freely on the axle so that the hunting is eliminated. The performance characteristics such as stability, curving behaviour and ride comfort are compared and analyzed by using these •independently rotating wheelsets. The vehicle with IRW has shown better ability in stability, curving behaviour and ride comfort than the vehicle with conventional wheelsets. But due to the decoupling of the wheels the IRW lacks the guiding ability. The guiding ability is provided by using partial couplings between wheels which provide some torsional rigidity and torsional damping, but with decreased good performance of vehicle with IRW but still better than the vehicle with conventional wheelsets. Vehicles with partial coupling between wheels and axles have shown an intermediate performance of vehicles with conventional wheelsets and IRW's