Dual Planetary EV Transaxle Layout for High Torque Packaging

The transmission system is divided into two separate planetary gearsets (first and second planetary gearsets) with different gear ratios, allowing each gearset to be optimized for specific torque requirements. This segmentation enables the use of smaller individual gearsets that collectively provide the full torque range, resolving the contradiction between torque output capability and packaging space.

The system dynamically switches between different gearsets and gear ratios based on real-time torque demands and operating conditions. The controller selectively engages the first planetary gearset for high-torque scenarios and the second planetary gearset for lower-torque scenarios, enabling the system to achieve high peak torque capability without requiring permanently large gearsets, thus resolving the packaging contradiction.

Instead of using a single complex high-ratio gearset, the system segments torque multiplication into two separate planetary gearsets with moderate gear ratios. Each gearset performs partial torque multiplication, and their combined effect achieves the desired overall torque multiplication. This segmentation simplifies each individual gearset design while maintaining the required torque multiplication capability.

Each planetary gearset is designed to provide partial torque multiplication rather than attempting to achieve the full torque multiplication in a single stage. The first planetary gearset provides torque multiplication for high-demand scenarios, while the second planetary gearset provides additional multiplication or direct drive for lower-demand scenarios, avoiding the need for an overly complex single-stage high-ratio system.