Research Topic
| Short Title | E-Mobility in Lager2/LFP |
| Start of Project | Q4/2024 |
| Funding | FVA-Nr. 701/V Research Association for Drive Technology e.V., FVA |
| Project Partner | Institut für Maschinenkonstruktion und Tribologie, IMKT, Leibniz Universität Hannover |
| Contact | Dr.-Ing. M. Otto |
Project Description
Due to the steadily increasing market share of electric vehicles, solutions are increasingly needed that make it possible to computationally investigate aspects particular to the field of e-mobility, in particular high-speed phenomena, friction losses, and possible damage caused by parasitic electric currents. An electric automotive drivetrain that can reach high speeds of over 30,000 RPM was developed within the scope of Speed2E and Speed4E, significantly reducing engine mass. At these speed ranges, the assumptions of existing bearing calculation methods are limited in their validity. Corresponding improved calculation approaches were developed as part of FVA 914 I. In this project, these methods will be extended to other bearing types and their applicability to entire e-drive trains will be investigated by means of a calculation study using the Speed4E transmission. The use of electric motors with frequency converters places electrical stress on bearings and damage mechanisms such as grey frosting or electrically-induced fluting can occur. In order to estimate the electrical load on a bearing, models of the bearing impedance originally developed in FVA 863 I (capacitance and resistance) are to be considered.
The Fortran-based calculation program LAGER2 represents the central tool within the FVA for the theoretical determination of bearing stiffness and lifetime. The newest methods and research results relating to bearing calculations are continually integrated. LAGER2 also provides the bearing calculation methods for the transmission calculation software RIKOR. Thus, LAGER2 is an essential tool for transmission developers and is crucial for the exact calculation of shaft positions or the load distribution as gear teeth contact. As part of the "Low Friction Powertrain" (LFP) research project and the “Efficiency-optimized gearbox" subproject, calculation models for rolling bearing friction were developed at the Institute for Machine Design and Tribology at the Leibniz University in Hanover. These models were comprehensively validated using extensive experimental data under varied bearing designs and sizes typically found in the automotive sector. These friction torque estimation methods were groundbreakingly based on real, experimentally determined rheological fluid properties and empirically showed good predictive power.