The Hyundai Motor Group has unveiled the Universal Wheel Drive System (Uni-Wheel), a new wheel design that’s claimed to revolutionize the design of future mobility products, particularly electric vehicles.

In a nutshell, the Uni-Wheel integrates an EV’s reduction gear (its transmission) inside the hollow part of the wheel. It eliminates the need to engineer ways to package CV joints and drive shafts neatly while ensuring the motor can transmit power more efficiently to the wheel. So, by using the Uni-Wheel design, EVs may get more interior room and more space for batteries.

The Uni-Wheel compromises a special planetary gear configuration made out of a central “sun gear,” orbited by four pinion gears and a ring gear. The power generated by an EV motor is sent to the sun gear, which turns the pinion gears, which then engages the outer ring gear.