Simulative Investigation of Rubber Damper Elements for Planetary Touch-Down Bearings

Designing touch-down bearings (TDB) for outer rotor flywheels operated under high vacuum conditions are a challenging task. Due to the big diameters conventional TDB are not suited and a planetary design is applied consisting of a number of small rolling elements distributed around the stator. Since the amplitude of the peak loads during a drop-down lies close to the static load rating of the bearings, it is expected that the service life can be increased by reducing the maximal forces. Therefore, this paper investigates the influence of elastomer rings around the outer rings in the TDB using simulations. For this purpose, the structure and the models used for the contact force calculation in the simulation software ANEAS are presented, especially the modelling of the elastomers. Based on the requirements for a TDB in a flywheel application three different elastomers (FKM, VMQ, EPDM) are selected for the investigation. The results of the simulations show that stiffness and material strongly influence the maximum force. The best results are obtained using the material FKM. Leading to a reduction of the force amplitude in a wide stiffness range.