Newly developed Cam-Roller follower Tester (CRT) with self-aligning mechanism in a line contact configuration and ways of simulating, detecting, and measuring surface initiated RCF cracks

Rolling contact fatigue damage represents the end life of all rotating machinery e.g. rolling bearings, gears, camshaft-roller followers, rail wheels etc. Typically, such components can operate under wide operating conditions from full film lubrication to boundary lubrication, depending on the application. For this study, focus is given on boundary conditions, where load is caried mainly via asperity-asperity interaction and less via lubricant. As such, two damage modes are competing with each other e.g. wear and surface/subsurface initiated rolling contact fatigue. In order to understand and predict these two complex damage/failure mechanisms, firstly a cam-roller follower tester was developed to experimentally reproduce such damages under laboratory controlled conditions. The newly developed tester is unique as it utilizes self-aligning mechanism in a line contact configuration and it truly resembles the dynamics of most rotating machinery i.e. one specimen is driven and the other one is follower. The main feature of the tester is to measure traction force under very low partial slip conditions. Secondly, two non-destructive testing (NDA) techniques are selected to detect and measure initiation (Electromagnetic Testing - ET) and propagation (Computed Tomography – CT) of surface initiated rolling contact fatigue cracks. Finally, the results from NDAs will be used to validate undergoing semi-analytical model being under development to
simulate the synergetic effect of wear and rolling contact fatigue on the end life of the component.