“Tribological solicitations” of piezoelectric inertia motors by means of in situ tribotesting and 3 rd body flow framework

In piezoelectric inertia motors, friction is not a synonymous of energy loss but is the source of motion. Their performances are thus prone to wear and friction coefficient variation. To address these issues, this paper first aims at improving the understanding of tribological solicitations by means of a dedicated in situ tribotesting while exploiting the 3 rd body flow framework. Beyond the introduction of transparent glass pins to see inside the contact in operation, the key of this work is to consider both the mechanism effect and the friction couple. As a result, a solution has been proposed to multiply the motor lifetime by more than ten while keeping stable speed performances, and, above all, without multiplying tests with numerous friction materials.