Investigating the Effects of Lubrication on Wheel-Track Dynamic Interaction via Experiments on a Twin Disc Test Rig

Abstract

Lubrication is widely used to reduce wear of wheel and rail profiles by decreasing the friction between the wheel flange and rail. The effects of wheel flange lubrication on the dynamic response of the wheel were investigated in this study, by analysing the responses of the adjoining bearing housing. The experiments were conducted on a 1/3rd scale twin disc rig, with a single wheel and a rail disc, which can have various speeds, loads and creepage. First, the theoretical modal parameters of the wheel were calculated by constructing a finite element model in order to obtain the shapes of interested modes. Then, Frequency Response Function (FRF) tests were conducted by exciting the rail disc on the laboratory rig and measuring the response of the bearing house. It shows that the FRF has a good agreement with the frequency domain signals of bearing housing responses when the rig is running under varying speeds. Last but not least, the responses of the bearing housing were measured when the rig was under four different constant speeds and three different loads. The tests were repeated for the wheel flange with and without lubricating grease. The results show that lubrication of wheel flange will result in a decrease of vibration amplitudes of the bearing housing in the frequency range of 6,000 Hz to 8,000 Hz when the rig under relative high loads. In addition, the lubrication will also lower some of the resonant frequencies of the wheel because of the oil film between the wheel and rail disc which was generated when the wheel flange was lubricated with grease.