Tribo-dynamic analysis of high-speed roller bearings for electrified vehicle powertrains

Roller bearings are critical components in electrified powertrains. At high speeds, the critical role of the elastohydrodynamic lubrication (EHL) cannot be ignored, necessitating a tribo-dynamic analysis. This paper investigates the behaviour of roller bearings under operating conditions present in high-speed electrified powertrains. The bearing motion is obtained experimentally using a novel experimental rig. The bearing centre’s orbital motion is acquired from the experiment and used as the boundary conditions for tribological analysis. Results reveal that the EHL film thickness increases from 0.2 to 1.9 micrometres across a speed range of 0 - 15 000 rpm. A comparison with conventional dry contact analysis shows that roller load can be underestimated if the lubricant film is neglected in the roller-race contact deformation.