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Rolling Element Bearings - Advanced Modeling for Multibody Simulations
ISSN: 0148-7191, e-ISSN: 2688-3627
To be published on April 14, 2020 by SAE International in United States
The electrification of vehicles, together with the ever-increasing need for more lightweight and durable designs, is putting the NVH performances of the transmission in the spotlight since the generated noises are not masked by the internal combustion engine. To correctly estimate the performances of the transmission while still in the design-phase, predictive models for the main components of the gearbox are of paramount importance. This paper focuses on the modeling of rolling element bearings, a key component that is responsible of transmitting the vibrations from the gear pairs to the surrounding structure while introducing additional excitation frequencies. The modeling techniques use the relative displacement of the rings to compute the corresponding reaction forces by calculating the equilibrium of each rolling element. To do so, the interaction between the rolling elements and the raceways can be modeled employing two different contact models depending on the level of accuracy required. The contact models are, respectively, a Hertz-Based approach that allows for fast computations, and an EHL (Elasto-Hydrodynamic Lubricated) contact model which accounts for the effects of lubrication. The procedure to calculate the equilibrium of the rolling elements allows for grasping the main effects, including centrifugal loads and misalignments. Thanks to the presented approach, this element is capable of correctly estimating the response of rolling element bearings on its 6-dof accounting for the coupling terms between different directions and to describe the load distribution over the rolling elements. These fast but accurate models for bearings are available in the portfolio of Siemens Digital Industry Software within the Simcenter 3D platform and complement the available advanced gear simulation technology recently released. To conclude, simulation results are carried out and validated against a full multibody model of a deep groove ball bearing to assess the accuracy and the efficiency of the proposed technique.