A parametric study of bogie rotation friction management utilising vehicle dynamic simulation

In 1999 QR introduced a fleet of 2500 new coal wagons with nylon bogie centre bowl wear liners into service in Central Queensland. Within months wheel wear on these wagons and other wagons were exceeding 5mm per 100,000km. Initial investigations focused on traditional causes of increases in wheel and rail wear such as badly profiled rail and poor rail/wheel lubrication. Wagon bogie rotational resistance was not considered until later following concerns raised regarding the possible additional rotational resistance created by the constant contact side bearers. Rotational resistance testing was undertaken by QR's Rollingstock Engineering Division in conjunction with Coal & Freight Services Group and some interesting results were found. The constant contact side bearings were not the source of major rotational resistance under the loaded wagon as first thought. Also the rotational resistance of the polymer liners was found to be excessive and concluded to be the root cause of the high wheel wear. A centre bowl lubrication programme was initiated and wheel wear was under control within two measurement periods with wheel life wear improved on all wagons, old and new. Since that time QR has undertaken extensive trials of different centre bowl types and found several more suitable materials which are now in use. In keeping with the above thrust, the Rail CRC Australia’s Bogie Rotation Friction Management project (Project 82) is investigating a range of factors that affect bogie rotation friction, including centre bowl friction, curve transition design and side bearer type. An extensive simulation-based parametric study was performed to determine the effects of varying side bearer type, centre bowl friction level, wagon loading conditions and speed on the wear characteristics of the wheelsets of a rail vehicle that runs on a selected track system. A 62 degree-of-freedom vehicle model was used for the simulations; the model was developed using the VAMPIRE® simulation package. New wheel and new rail profiles were used for the analysis to give an indication of the initial wear characteristics of the wheelsets. In this paper, an analysis of the results obtained is presented and conclusions are drawn based on the findings.