Review on Design and Structural Analysis of a Differential Gearbox and Casing for Electric Vehicles

Abstract

The rapid growth of electric vehicles (EVs) necessitates innovative approaches to improve power transmission efficiency, reduce weight, and enhance overall vehicle performance. A critical component in EV drivetrains is the differential gearbox, which transfers torque from the electric motor to the drive wheels while allowing differential wheel speeds during cornering. Conventional gearboxes, typically constructed from heavy cast iron or steel, significantly increase vehicle weight, adversely affecting energy efficiency and battery range. This study focuses on the design, modeling, and structural analysis of a single-speed, two-stage reduction compound differential gearbox and its casing, specifically optimized for EV applications. Finite Element Analysis (FEA) is employed to evaluate stress distribution, deformation, and thermal behavior under varying torque loads. The study explores alternative lightweight materials to replace traditional metals without compromising mechanical strength or durability. The proposed design aims to optimize structural performance, reduce overall weight, and ensure reliability under operational conditions. Results from this research provide valuable insights for developing advanced, lightweight differential gearboxes that enhance EV efficiency, improve driving range, and meet modern performance and durability requirements.

Introduction

The text presents a detailed study on the design, modeling, and analysis of a lightweight differential gearbox specifically tailored for electric vehicles (EVs). As EV adoption accelerates, conventional internal combustion engine (ICE) gearboxes—typically made of heavy cast iron or steel—are increasingly unsuitable due to their excessive weight, which negatively affects battery efficiency, driving range, and overall vehicle performance. The differential gearbox is a critical EV component, responsible for torque distribution and smooth wheel rotation during cornering, making weight reduction and efficiency key design priorities.

The study focuses on developing a single-speed, two-stage reduction differential gearbox optimized for EV drivetrains. A two-stage reduction system enables compact design and effective torque multiplication while accommodating the wide speed range of electric motors. Emphasis is placed on the gearbox casing, which must withstand mechanical loads, thermal stresses, and vibration while ensuring proper lubrication, noise reduction, and structural integrity.

To achieve these goals, the research employs CAD modeling and Finite Element Analysis (FEA) using ANSYS to evaluate static stress, deformation, modal behavior, thermal performance, and dynamic loading conditions. Modal analysis is used to identify natural frequencies and avoid resonance, which is crucial for reducing noise, vibration, and harshness (NVH). The study also explores topology optimization to eliminate low-stress regions and further reduce weight without compromising strength.

The literature review highlights significant advancements in EV gearbox design, particularly the use of lightweight materials such as aluminum, magnesium, and hybrid composites, which have demonstrated weight reductions of 25–50% while maintaining structural performance. Prior studies emphasize the importance of FEA, modal analysis, thermal-structural integration, and material substitution. However, most existing research lacks a holistic approach that simultaneously integrates structural, thermal, vibrational, and dynamic analyses tailored specifically to EV operating conditions.

Identified research gaps include limited exploration of advanced composites, insufficient multi-objective optimization, lack of real-world dynamic load simulations, and minimal experimental validation. The proposed methodology addresses these gaps by combining advanced material selection, integrated FEA (static, modal, thermal, and dynamic), and design optimization for EV-specific requirements.

Conclusion

The reviewed literature underscores the growing emphasis on designing lightweight, efficient, and reliable differential gearboxes for electric vehicles (EVs). Studies consistently demonstrate that substituting conventional materials like cast iron and steel with aluminum, magnesium, or hybrid composites significantly reduces weight while maintaining structural integrity. Finite Element Analysis (FEA), combined with modal, harmonic, and thermal analyses, has emerged as a critical tool for optimizing gearbox design, ensuring durability, minimizing vibration, and enhancing NVH performance. Topology optimization and geometry refinement further improve weight-to-strength ratios and operational efficiency. However, most studies focus on individual aspects—material selection, structural analysis, thermal management, or vibration control—rather than adopting an integrated, multi-objective approach. Additionally, real-world dynamic loading and manufacturability considerations are often underexplored. This review highlights the need for comprehensive methodologies that simultaneously address structural, thermal, and vibrational performance using advanced materials tailored specifically for EV differential gearboxes. Implementing such holistic approaches can significantly enhance EV efficiency, reliability, and driving range, guiding future research and design strategies in this domain.

References

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Copyright

Copyright © 2026 Ms. Sneha Siddharth Sahare, Dr. M. Shakebuddin, Dr. Akash M. Langde. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.