Four-point contact slewing bearing dynamics. Guidelines for FE modelling and mechanistic model correlation

Abstract

The vibrational response of mechanical systems including four-point contact slewing bearings is heavily influenced by the stiffness and damping properties of the bearing joint itself. As an initial approach to study the dynamic response of these components, in this work several aspects are addressed. With a view toward dynamic modelling, first, a FE-based modification of the force-deflection Hertz formula is proposed to simulate more accurately the ball-raceway contact, including the effect of the conformity, and thus providing a more accurate formula that can be used also for solving static load distribution problems. Then, novel guidelines regarding the dynamic FE modelling of these components are provided for two complexity levels: an accurate one and a simplified one. Simultaneously, a mechanistic model to simulate the dynamic response of these bearings under axial loads is proposed. This latter model is validated against an ad-hoc developed FE model, demonstrating its efficiency. Finally, the energy dissipation due to material hysteresis is implemented into the mechanistic model through different damping models, and their performance is compared with results provided by a FE accurate model with a view toward implementing them in FE simplified modelling techniques for future experimental correlation.