Configuration design and kinematic analysis of compound power-split mechanisms for in-wheel motor-driven electrical vehicles
Year: 2025
Type: article
Abstract: This paper presents a systematic approach for configuration design and kinematic analysis of two-input compound power split mechanisms (CPSMs), specifically designed for electric vehicles powered by in-wheel motors. Motivated by growing demand for compact, highly efficient, multi-mode electric propulsion systems, the study addresses the challenge of achieving high torque using lightweight, high-speed electric motors constrained by in-wheel motors. The proposed methodology synthesizes CPSMs by modeling two-degree-of-freedom compound planetary gear trains (PGTs), integrating dual electric motors and a one-way clutch (OWC) into a compact transmission unit. A generalized speed-ratio framework is developed to analyze all possible gear coupling combinations, derive operating conditions, and evaluate torque-speed relationships across six major operating modes, including engine drive, regenerative braking, and continuously variable transmission (CVT). Using sequence-based speed analysis and gear ratio ranges, its identified 11 candidate CPSM configurations and 18 speed-ratio ranges that meet all three design requirements necessary for high-power-density operation: (1) ensuring at least one motor rotates faster than the output to maintain torque amplification at power mode; (2) maintaining feasible speed ratios; (3) achieving appropriate power flow direction. Selected configurations were validated against patented benchmarks from literature, confirming the accuracy of the derived kinematic models and speed ratios. This work contributes to a precise and scalable CPSM design framework applicable to electric vehicle architectures. It enables early synthesis of multi-mode in-wheel drive transmissions without the need for detailed gear dimensions and supports highly efficient operation using compact motor technologies. Future expansions include dynamic modeling, real-time control strategies, and experimental prototyping.
Source: Results in Engineering
Institution: University of Al-Qadisiyah
Language: English
Subfield: Automotive Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,940
OpenAlex ID: W4416552782