Hyundai Motor Company and Kia Corporation have introduced the ‘Uni Wheel’ drive system, at the ‘Uni Wheel Tech Day’ in Seoul, Korea. This system intends to transform the design of future mobility devices, offering improved space utilisation and enhanced driving capabilities.
Space-Efficient Uni Wheel System
The Uni Wheel is a functionally integrated wheel drive system that redefines the structure of electric vehicles (EVs). By relocating the main drive system components within the wheel hub, Hyundai Motor and Kia have created a new design that increases the available interior space of an EV.
Flat-Floor Configuration and Reduced Drive Shaft Length
Traditional EVs rely on a drive system similar to internal combustion engine (ICE) vehicles, using drive shafts and constant velocity (CV) joints. However, Uni Wheel’s design opens up new possibilities by moving the reduction gear inside the wheel hub, reducing the length of drive shafts. This enables a flat-floor configuration, freeing up more interior space compared to conventional drive systems.
Multi-Axis Movement and Improved Suspension Articulation
The Uni Wheel incorporates a unique planetary gear configuration, allowing multi-axis movement with a wide range of suspension articulation. Unlike conventional drive systems, Uni Wheel maintains power transmission efficiency regardless of wheel movement, ensuring high durability and ride comfort, especially on uneven surfaces.
Torque Vectoring and Driving Stability
With independent control of up to four efficient electric drive units, Uni Wheel offers unprecedented torque vectoring capabilities. This enhances dynamic ability and provides high levels of steering and driving stability. The high reduction ratio of the Uni Wheel delivers substantial torque output, enabling a more compact electric motor.
Efficiency, Interior Space, and Adaptability
The Uni Wheel concept not only optimises efficiency but also liberates additional space within the vehicle. By downsizing the electric motor without sacrificing performance, the extra space can be utilised for cargo, contributing to a larger trunk or a ‘frunk.’ Uni Wheel’s adaptability extends beyond passenger vehicles, making it suitable for various EVs, including high-performance models, as well as mobility devices like wheelchairs, bicycles, and delivery robots.
Enhanced Battery Packaging and Range
Uni Wheel’s innovative battery packaging minimises the impact on passenger space, a common challenge in conventional EVs. This feature is particularly valuable for Purpose Built Vehicles (PBVs), allowing for a low, flat-floor design that maximises interior space. Uni Wheel can be scaled to work with wheel sizes as small as 4 inches and as large as 25 inches or more. The flexibility of the Uni Wheel also facilitates the improvement of driving range by optimising battery capacity.
Continuous Testing and Patent Applications
Hyundai Motor and Kia are rigorously testing the stability, efficiency, and durability of the Uni Wheel through various trials. Additionally, they have applied for and registered eight patents related to Uni Wheel in South Korea, the United States, and Europe.