Effects of Axle Box Lateral Clearance and Friction Coefficient on Dynamic Stability and Wear of 3-Piece Bogies

Three piece bogies are commonly used in worldwide as freight wagons. Manufacturing and maintaining expenses are noticeably less than other types of freight wagons. Therefore many investigators have focused on optimization of these bogies in order to improve their performance. These bogies have been reported to have bad performance both in curved and straight pads. High number of wear in both contact points has been observed. In this investigation, a freight wagon equipped with a pair of three piece bogies is simulated in Universal Mechanism software to observe its hunting and wear behaviour. Parameters of lateral clearance and coefficient of friction are investigated to see their effects on vehicle behaviour. The results show that as the lateral clearance or coefficient of friction increase, the nonlinear critical speed would decrease and this would lead to encounter different nonlinear critical speeds for rear and front bogies. The lateral clearance has little effects on decreasing friction work in both contact points in transient section of curves due to the considered wheel-rail profiles.