Structural Damping in the Isolation Path of Electric Drive Units in Electric Vehicles
2022-01-0731
03/29/2022
- Event
- Content
- Electric Vehicles (EV) pose special challenges for isolating structure borne noise and vibration originating from the electric drive unit. The characteristics of the tonal noise and the frequency range of the source vibration make conventional isolation devices not adequate or appropriate for EV applications. For example, internal combustion engine powertrains have a primary frequency of concern up to 800 Hz., while electric drive unit frequency of concern can be up to 3000 Hz. In addition to the elastomer-based components in the isolation system, structural components have become even more critical for vibration transmissibility given the tonal nature and the high frequency range of the source energy. A novel approach to mitigating high frequency vibration isolation by utilizing new grade of PA66 glass-filled nylon resin with high structural damping will be discussed. The new grade resin was specifically developed for the all-new Cadillac LYRIQ EV drive unit mount structural support brackets where the brackets are tuned along with the elastomeric bushings to provide broad band vibration filter. This resulted in mass- and cost-efficient solution for electric drive unit isolation. It is contemplated that comprehending structural damping in the isolation path has broader impact in the field of vibration control. Requirements for the new nylon resin, specialized testing, design and tuning strategy of the brackets, and component and vehicle level vibration and sound pressure level improvements will be discussed. In addition, special considerations for durability loads and structural strength were critical part of the material development and component design and will also be discussed.
- Citation
- Jomaa, S., Balaceanu, A., and quaggiotto, M., "Structural Damping in the Isolation Path of Electric Drive Units in Electric Vehicles," SAE Technical Paper 2022-01-0731, 2022, .