Tribological investigation of truncated thermo-elastohydrodynamic elliptical point contacts in high performance transmissions

In high performance cars, light-weighting is a major development driver. Consequently, the transmission can be particularly compact whilst being subject to large variations in torque and power. Pitch line velocities of up to 52 m/s and contact pressures of up to 3 GPa are routinely encountered under race conditions. Contact patch asymmetry due to angular misalignments between input and output shafts leads to the generation of high contact edge pressures, with the potential of inducing fatigue spalling, which can be exacerbated by observed and yet unexplained contact footprint truncation. Crowning is widely used as a palliative measure for these undesired conditions. The paper provides a time-efficient analytical method to solve the non-Newtonian mixed thermo-elastohydrodynamic (TEHD) problem under the extreme prevalent conditions in such high performance vehicle transmission systems. The approach expounded in this paper for the extreme tribological conditions has not hitherto been reported in literature.