Kia Corporation and Hyundai Motor Company have unveiled the Universal Wheel Drive System — called ‘Uni Wheel’ — at ‘Uni Wheel Tech Day’ in Seoul, Korea.
This paradigm-shifting vehicle drive system will revolutionise the design of future mobility devices.
Uni Wheel is a functionally integrated wheel drive system that dramatically improves available space inside an electric vehicle (EV) by moving the main drive system components to the vacant space within the wheel hub. In doing so, Kia and Hyundai Motor have designed a completely new structure for the drive system.
In internal combustion engine (ICE) vehicles power is transmitted from the engine through the transmission and to the wheels via drive shafts and constant velocity (CV) joints. In EVs, the engine and transmission are replaced by a motor and reduction gear, but the final method of transmission to the wheels is the same.
Uni Wheel opens new possibilities and enables a flat-floor configuration by moving an EV’s reduction gear inside the wheel hub, locating a compact individual motor close to each wheel, reducing the length of the drive shafts.
The system frees up significantly more interior space compared with conventional drive systems, enabling future mobility products optimised for various applications, such as Purpose Built Vehicles (PBVs).
Until now, the in-wheel motor hub has been used only on specialist vehicles requiring high maneuverability, usually at lower speed and some purely mechanical systems were tested in the middle of the last century to ease parking in city street using a ‘jockey’ wheel concept which dropped down from the chassis.
Hyundai and Kia have not said when their new system will first appear in a road vehicle.