A new collaboration between Hyundai Motors and KIA may help free up space in future EVs. The net result of this new design is redesigning the drive system structure as a whole, as the reduction gear and motor now lives in the wheel hub, freeing up space in the body of the car.
The Uni Wheel works by moving the main drive system components to the vacant space within the wheel hub, which includes the reduction gear to regulate the power that comes out of the electric motor.
Uni Wheel uses a special planetary gear configuration consisting of a sun gear in the centre, four pinion gears on each side and a ring gear surrounding this arrangement. 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. The pinion gears inside are connected to form two linkages, and this multi-link mechanism enables Uni Wheel’s multi-axis movement to allow a wide range of suspension articulation.
This new linkage system can transmit power to the wheels with almost no change in efficiency when compared to the traditional method of transmitting power from the motor to the wheel. When used in tandem with electronic air suspension that can adjust ride height according to the driving situation, the vehicle can be adjusted according to the driving situation. So if rough roads ahead, the height can be adjusted accordingly and if high-speed driving is in the books, the car can be lowered for better power and stability – all without any significant loss of energy.
By moving an EV’s reduction gear inside the wheel hub, the Uni Wheel will help free up space in the cabin of the car, which can lead to a roomier interior as well as a flatter floor. EV manufacturers can create optimized designs such as Purpose-Built Vehicles (PBVs).
Uni Wheel is highly flexible and easily adaptable to all types of EVs, including regular passenger and high-performance EVs, as the system can implement the same powertrain and reduction gear functions required for conventional EVs.
Another interesting idea that can utilize Uni Wheel is a next-generation motorized wheelchair, as the Uni Wheel can be installed in wheels with a diameter as small as 4 meters.
Neither Hyundai nor KIA shared when the first production cars with Uni Wheels will be made available to the public, but we hope that it can come to market pretty soon.
