Electric Motor Mounting System Validation with Subsystem and Powered e-Axle Tests

Abstract

<div class="section abstract"><div class="htmlview paragraph">As more and more electric vehicles on dedicated platforms are being developed and launched, motor mounting systems evolve to focus on the specific requirements of the electric drive units (EDUs) – especially the partially opposing targets of controlling powertrain motion under torque and enhancing high frequency isolation. The initial layout of the EDU mounting system, such as the number, position and orientation of the motor mounts as well as their linear and non-linear stiffness properties, during the quotation phase as well as its continuous optimization after business nomination are the foundation for an optimal NVH performance. To support early-stage model validation, Vibracoustic analyzes the modal properties of the EDU or the EDU / subframe assembly to ground. For more comprehensive investigations, Vibracoustic has devised unique axle test rigs to analyze and optimize the NVH of entire axles without the surrounding vehicle. Load cells at all interface points, acceleration sensors and other signal sources permit a comprehensive NVH characterization of an axle. Upgrading the axle test rig with a battery simulator, external liquid cooling and an automation system has enabled the NVH investigation of electric axles under their own power – an industry first. A recently added optical kinematic measurement system now allows the tracking of all 6 DOF motions of any axle and driveline component, e.g. under EDU torque or due to wheel excitations. In this paper, we will share a first correlation study of measurements with multi-body simulations for both test approaches – the simplified experimental modal analysis and the optical kinematic measurement of a full powered e-axle test on a chassis dyno.</div></div>