Camille JEANNOT : "Considering rings waviness and flexibility to model static behaviour of ball bearings with thin rings"

Abstract : The study of high precision ball bearings requires the development of more and more complete models. Taking into account shape defects, and more specifically rings waviness, is a major issue. These have an impact on the performance of the bearing. They can affect the stability of the bearing's axis of rotation and generate a residual moment, impossible to determine with classical equilibrium methods. To address this problem, a highly modular energy formulation has been developed. It allows to quantify the impact of races waviness on the geometrical and mechanical parameters of the bearing, at the macroscopic and mesoscopic scales. This is possible thanks to the implementation of a contact model allowing the calculation of both normal and tangential forces, based on Hertz and Dahl theories.
The second issue of this thesis concerns the consideration of the flexibility of the rings, especially for the study of annular bearings with very thin section. For this, a modeling of the rings using continuous elements has been proposed. The static equilibrium of the bearing is then solved with an energetic approach to which constraints are added, such as the suppression of rigid body movements, an essential condition formulated analytically while taking care not to modify the shape of the deformation. Some experimental validations of the models are also proposed through the measurement of the wobble, the friction torque and the radial deformation of the rings.

Jury Composition  :

Daniel NELIAS, Professeur des Universités, LaMCoS, INSA Lyon, Reporter

Alain DAIDIE, Professeur des Universités, ICA, INSA Toulouse, Reporter

Jean-Baptiste CASIMIR, Professeur des Universités, Quartz, SUPMECA, Reviewer

Pierre-Alain BOUCARD, Professeur des Universités, LMPS, ENS Paris Saclay, Reviewer

Gaël CHEVALLIER, Professeur des Universités, FEMTO-ST, Université de Franche-Comté, PhD Director

Emeline SADOULET-REBOUL, Maître de Conférence HDR, FEMTO-ST, Université de Franche-Comté, Co-PhD Director

Stéphane DUFRENOY, Docteur ingénieur R&D, ADR, PhD Supervisor

Cyrille LEBRETON, Directeur technique, ADR, PHD Supervisor

Localization : Amphithéâtre J-J Gagnepain- Institut FEMTO-ST  - 15B, Avenue des Montboucons - Besançon