Hyundai and Kia have applied for and registered patents for a universal wheel drive system (Uni Wheel) that the automakers say could create an entirely new vehicle cabin structure.
The automakers presented the new system — which uses a special planetary gear configuration — Wednesday in Seoul, South Korea. The system consists of a sun gear in the center, four pinion gears in each corner, and a ring gear.
“Power generated by the motor is transmitted to the sun gear, which in turn engages the pinion gears to rotate the ring gear. This is connected to the wheel to drive the vehicle,” Hyundai said in a press release. “Uni Wheel’s pinion gears are connected to each other to form two linkages and this multi-link mechanism enables Uni Wheel’s multi-axis movement to allow a wide range of suspension articulation.”
According to Hyundai, the system saves space inside an electric vehicle (EV) by moving the main drive components to the empty space within the wheel hub. The OEM said this approach has led to a “completely new structure” for the drive system.
In internal combustion engine (ICE) vehicles, Hyundai said the power is transmitted from the engine through the transmission and to the wheels via drive shafts and constant velocity 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,” Hyundai said. “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.”
Hyundai said the system frees up more interior space compared to conventional drive systems. By moving drive system compartments to the wheel hub and downsizing the motor, the extra space can be used as extra cargo room or to increase passenger space in the cabin, it added.
“It’s also possible to move away from conventional seating arrangements designed around the driver, creating new interior layouts and designs for the era of fully autonomous driving,” Hyundai said. “Utilizing this space to improve battery capacity can also improve driving range, meaning users can achieve the range of a large EV without the physical size of the vehicle growing.”
Jongsool Park, senior fellow at the Hyundai Motor Group Institute of Advanced Technology Development, said the design could be a “game changer” for the automotive market.
“We will perfect the technology so that customers can experience mobility in a completely different and new way,” Park said.
Hyundai said patents for the system have been applied for and registered in the U.S., South Korea, and Europe.
All images courtesy of Hyundai