Drive train

Critical torsional vibrations in the electric drive train

Critical torsional vibrations in the electric drive train

In its current case study, Rotec is investigating torsional vibrations in the electric drive train. Torsional vibration effects were found in the transmission and e-motor, which influence the acoustic driving comfort. In addition, critical torsional vibrations occurred due to feedback, which caused dynamic loads on the drive. The case study can be downloaded from the company website.

The shift to electric mobility is gathering pace. Already today, 10.9 million e-cars (2020) are rolling across the globe worldwide and this number will increase to 34 million by 2030 (Ceresana forecast). In the development of e-drive trains, the focus is on electric storage capacity, the weight and size of the e-machine, as well as on durable drivetrain components, driving comfort, and the ability to drive.

powertrain components, driving comfort and thus silent driving. Standard NVH analysis systems use airborne and structure-borne sound signals to investigate the generated noise, vibrations and their transmission paths. However, these usually ignore the mechanism of how these effects are generated.

In Rotec's case study, it is clear that the acoustic behaviour of the drive is influenced by, among other things, torsional vibration effects from gear components and the electric motor. In addition, increased torsional vibrations due to feedback effects such as bumps in the road or driving safety systems (ABS) were found to lead to dynamic loads on the electric drive train. Investigated parameters and recommended solutions are explained in the case study.

The case study can be downloaded here.