Independently Rotating Wheels for High Speed Trains

The results of an analysis of the dynamics of individually rotating wheel systems for use on high speed rail vehicles are presented in this paper. The objective of the system is to remove the hunting stability problems of conventional rail-wheel systems and thus improve ride comfort and safety. The analysis indicates that the use of independently rotating wheel systems eliminates the standard hunting instability, but it introduces a lightly damped but stable oscillation of its own. However, by increasing the yaw stiffness between the wheels and the vehicle body the frequency of this oscillation can be moved beyond the low point in the human vibration tolerance limit. When this is done the ride response is improved over that for an integral wheel system.