Solid EV Axle With Hub Motors for Selective Torque Transfer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric vehicle axles lack efficient torque transfer and traction management between wheels, particularly in low-traction conditions, limiting their performance in all-wheel-drive configurations.
Innovation Solution
The implementation of a solid axle with interconnected wheel assemblies and a clutch system that allows selective coupling of electric machines to an axle shaft, enabling torque transfer and traction distribution between wheels, with modes for independent operation, locked rotation, and slipping engagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If independent electric machines power each wheel independently, then each wheel can operate autonomously, but torque transfer between wheels is inefficient limiting all-wheel-drive performance
Solution Approach 1:
An idle electric machine is introduced as an intermediary component between the two powered wheel assemblies. This idle machine serves as a torque transfer medium, enabling efficient torque distribution between wheels while maintaining the capability for independent wheel operation when needed.
Solution Approach 2:
The idle electric machine performs multiple functions: it can remain inactive to allow independent operation of powered wheels, or it can be engaged to transfer torque between wheels during low-triction conditions, effectively serving both independent operation and torque transfer roles.
2Reliability
If a clutch system selectively couples electric machines to the axle shaft, then torque transfer is improved, but device complexity increases
Solution Approach 1:
The clutch system provides dynamic coupling and decoupling capabilities, allowing the electric machines to be selectively connected or disconnected from the axle shaft based on operating conditions. This enables the system to adapt between independent wheel drive mode and torque transfer mode.
Solution Approach 2:
The drivetrain is segmented into independent controllable units with clutches positioned at strategic locations. This segmentation allows selective engagement of torque transfer paths without requiring a completely integrated system, managing complexity through modular control.
Data Source
AI summary
An electrified vehicle axle includes a first wheel assembly having a first electric machine configured to power a first wheel and a second wheel assembly having a second electric machine configured to power a second wheel. A beam has a first end connected to the first wheel assembly and second end connected to the second wheel assembly. An axle shaft is supported for rotation within a hollow center of the beam and is configured to transfer torque between the first and second electric machines. At least one clutch selectively couples at least one of the electric machines to the axle shaft.