In a groundbreaking announcement poised to reshape the landscape of vehicle propulsion, Hyundai Motor Group has unveiled a pioneering drive system named the ‘Universal Wheel Drive System’ (Uniwheel). The revelation, made during the ‘Uniwheel Tech Day’ held in Myeongdong, Seoul on November 28, introduces a structural revolution by integrating essential vehicle components within the wheel.
Traditionally, the space between wheels has been reserved for components such as the engine, transmission, drive shaft, and constant-velocity (CV) joint. Even with the advent of electric vehicles (EVs), the basic drive system structure has remained relatively unchanged. Uniwheel, however, disrupts this norm by embedding the functions of the reducer, drive shaft, and CV joint into the wheel itself.
The Uniwheel design not only liberates valuable space between the wheels but also enhances vehicle ride comfort and durability. This breakthrough is positioned as a technological ‘game-changer’ in the era of electrification, marking a departure from the conventional limitations imposed by the layout of traditional components.
One of Uniwheel’s key advancements lies in its planetary gear structure and multi-link mechanism design. The system incorporates a centrally located sun gear, four pinion gears on both sides, and an outer ring gear. Power generated by the motor is transmitted to the sun gear, initiating the rotation of the ring gear connected to the wheel.
Unlike conventional CV joint-equipped drive shafts, the Uniwheel maintains consistent power transmission efficiency under various movements, ensuring durability and ride comfort. The multi-link mechanism of the pinion gears enables smooth vertical and horizontal movements, adapting to different surfaces and terrains.
Hyundai and Kia are actively developing a Uniwheel with an increased gear ratio to achieve high torque with smaller motors. This innovation will allow for independent control of driving power for each wheel, resulting in superior steering, driving stability, and torque vectoring.
The flexibility of Uniwheel extends beyond its mechanical advantages. The liberated space between wheels can be repurposed, potentially serving as additional cargo space in the trunk and front. Incorporating additional batteries can significantly enhance driving range, opening avenues for purpose-based vehicle (PBV) designs tailored to customer needs.
The Uniwheel’s adaptability makes it suitable for various types of electric vehicles, including standard sedans, high-performance EVs, wheelchairs, bicycles, and robots. Hyundai and Kia are committed to refining the Uniwheel further by adjusting the gear ratio and enhancing the lubrication cooling system, aiming to maximize its market potential.
Park Jong-sool, a senior researcher at the Hyundai and Kia Research and Development Center, expressed enthusiasm, stating, “This is an innovative idea that can be a game-changer in the future mobility market.”
