These slides were presented at the NAFEMS World Congress 2025, held in Salzburg, Austria from May 19–22, 2025.

Abstract

This paper explores the mechanical and NVH (noise, vibration, and harshness) challenges in developing high-performance electric drive systems, with a focus on the design, simulation, and physical testing of transmission housing. As a key component in modern electric vehicles (EVs), the transmission housing is essential for meeting stringent NVH standards while ensuring structural integrity under demanding dynamic conditions. A key challenge in transmission housing design is ensuring it can withstand high forces, particularly during sport or deceleration modes when the e-motor generates significant torque. Simultaneously, minimizing NVH emissions is crucial to meet the performance expectations of electric vehicles. A specific NVH issue addressed in this study is gear whining, a high-pitched noise generated by the meshing of gears under certain driving conditions. This noise, often perceived as intrusive, is particularly noticeable during specific load conditions and needs to be mitigated to improve the overall driving experience. The engineering process begins by translating vehicle-level NVH targets into specific component-level requirements, enabling a focused approach to solving individual challenges. High-fidelity digital twins model the mechanical and NVH characteristics of the transmission housing, allowing for early-stage testing and optimization. This reduces reliance on costly prototypes and accelerates development. However, physical testing remains essential to validate digital models and ensure their accuracy. Comprehensive NVH testing campaigns at both the component and system levels help calibrate the models and confirm the design'™s effectiveness in mitigating noise, including gear whining. A case study on the e-drive gearbox housing demonstrates the effectiveness of this integrated approach. Experimental data from pre-test and validation phases refine the digital twins, ensuring accurate predictions of vibro-acoustic and structural behavior. The iterative process ensures the transmission housing meets NVH, durability, and mechanical performance targets while adhering to budget and timeline constraints. By combining advanced simulation techniques, digital twin technology, and rigorous physical testing, this approach streamlines the development process, minimizes risks, and reduces costs. The results show significant reductions in noise, including the reduction of gear whining, along with improved structural performance. In conclusion, this paper highlights the importance of integrating testing and simulation in the development of electric drive systems. The combined use of virtual and physical testing helps meet the demanding NVH standards of the electrified mobility market, ensuring optimal performance.