Increasing Bearing Life-Time of Mobile Flywheels by Using Bearing-Less Drive Methods

Fully electric and hybrid electric power trains enable reuse of braking energy. This decreases the amount of lost energy dramatically, especially for discontinuous operation. Good examples are urban traffic, public transportation or delivery services. Mobile flywheels provide an excellent potential for the emerging market of electrified power trains, but they are currently only used in a few applications such as motor sports (Formula 1, Le Mans, GT3 car racing). To enable a wider use in personal or public transportation, the life-span of the flywheel’s bearings have to be increased significantly. This paper presents an alternative approach to extend the life-span of the rolling element bearings by using bearing-less drive methods.