Abstract

The investigation discusses the analysis of bearing seat wear in aluminium housings of electric drive units. The primary focus was on utilizing finite element simulations in Abaqus to analyse the slippage between outer bearing ring and housing as a basis for wear. A main challenge was to build up an accurate 3D bearing model with moving rolling bodies that runs within an acceptable simulation time. With this respect, the main focus was on the very complex behaviour of deep groove ball bearings.

The study concentrates on the relative tangential slippage of the outer bearing ring relatively to the housing and the according contact pressure. The simulated slippage between coincident points of the outer ring and the housing can be summarized as a rotational movement superposed by a forward/backward slipping of sinusoidal type.

The Frictional Energy Density parameter (FED) was introduced as a measure for bearing seat wear and describes the energy dissipated through slipping. Various factors influencing the FED parameter and hence bearing seat wear were examined, including different radial loads, oversize at the outer ring, stiffness of the housing, friction coefficient, number of rolling bodies etc.

The FED parameter is computed within a postprocessing tool and displayed similarly to a contact pressure on the contact surface and correlates well to wear pictures from tests. The main contribution to the FED is coming from the forward/backward slipping occurring each time a rolling body is passing by. The global rotation of the outer ring has a lower effect.

Slide deck

Presenter Bio

Andreas Häubl, born in 1989 in Austria, is a dedicated technical engineer with a passion for climbing and mountain sports. His technical education began in Steyr (secondary school), where he specialized in automotive engineering. He furthered his education at the University of Applied Sciences Upper Austria (campus Weis) focusing on mechanical engineering with a specialization in simulation.

In 2014, he began his journey in the field of mechanical engineering with a diploma thesis on the development and strength analysis of a measurement rim at Magna Powertrain (Engineering Center Steyr). From 2015 to 2021, he worked as a calculation engineer at hofer forschungs- und entwicklungs GmbH close to Steyr. During this period, he concentrated on strength calculations in gearbox development in the automotive field performing detailed FE analysis.

Since 2022, Andreas has been employed at Magna Powertrain (Engineering Center Steyr), within the Structural Analysis Department. In his current role as a strength and fatigue calculation engineer, he conducts both linear and non-linear finite element analyses with Abaqus. Generally, his work involves durability analysis and structural optimizations for various automotive components including electric drive units and chassis and frame components. Due to the increasing relevance of e-mobility, the simulation tasks changed over the last years. One example is the increased shaft speed of e-drives, which has an influence on bearing wear at the aluminium bearing seat. Therefore, a detailed simulation model is currently investigated and an according evaluation method established, to reproduce bearing slippage at the aluminium housing with FE simulation.