Hyundai and Kia present Uni Wheel, a new flexible and adaptable “universal drive system” to increase the autonomy of electric cars

The global mobility market is moving slowly but inexorably towards a 100% electric future. This brings modifications to design techniques and mechanical components, many of them reduced to a minimum. However, one component that has remained relatively unchanged in the transition from internal combustion engine vehicles to electric vehicles is the powertrain.

In cars with an internal combustion engine, power is transmitted from the engine through the transmission and to the wheels via driveshafts and CV joints. In electric vehicles, the motor and transmission are replaced by a motor and gearbox, but the final method of transmission to the wheels is the same.

To solve this problem, Hyundai Motor Company and Kia Corporation have introduced a new universal drive system called “Uni Wheel” which can create even more platform space while maintaining the efficiency necessary for effective electric vehicle range.

Presented at the “Uni Wheel Tech Day” in Seoul, The Uni Wheel is a functionally integrated drive system that dramatically improves the space available inside an electric vehicle by moving the main components of the drive system to the free space of the wheel hub. To achieve this, Kia and Hyundai Motor have designed a completely new structure for the drive system.

Uni Wheel’s innovative design allows for a flat-floor configuration by placing the electric vehicle’s reduction gear inside the wheel hub. This means that the compact single motor can be located close to each wheel, thus reducing the length of the drive shafts.

As a result, Uni Wheel creates more interior space compared to conventional propulsion systemsproviding greater flexibility for future mobility products optimized for different applications, including purpose-built vehicles (PBV).

Uni Wheel features a unique planetary gear system that includes a central sun gear, four pinion gears on each side and a surrounding ring gear. The motor produces energy that is sent to the sun gear, which in turn meshes with the pinions. These pinions, in turn, rotate the ring gear connected to the wheel, which propels the vehicle forward. The sprockets of the Uni Wheel are linked together, forming two links, and this multi-link mechanism allows multi-axis movement of the Uni Wheel, which enables a wide range of suspension articulation.

Besides, Uni Wheel can transmit power with little change in efficiency, regardless of wheel movement, which guarantees great durability and driving comfort even when driving on uneven and undulating surfaces. In contrast, a conventional drive system using a normal CV joint suffers from decreased efficiency and durability as the driveshaft deflection angle increases.

By moving most of the drivetrain to the wheels, the high reduction ratio of Uni Wheel provides significant torque output and allows for a more compact electric motor. With independent control of up to four efficient electric propulsion units, Uni Wheel also enables unprecedented levels of torque vectoring to increase dynamic capability and deliver high levels of steering and handling stability.

The Uni Wheel concept frees up space inside a vehicle that can be used as additional cargo space, like a larger trunk or a “frunk.” The extra space could also be used for more battery, thus improving the range of electric vehicles without making them physically larger.

Uni Wheel is a very flexible and easily adaptable system that can be integrated without problems into different types of electric vehicles. It offers the same powertrain and reduction gear functions as traditional electric vehicles, making it compatible with both regular passenger cars and high-performance electric vehicles. Uni Wheel can also be applied to other mobility devices, such as wheelchairs, bicycles and delivery robots, and can be scaled to work with wheels ranging from 4 to 25 inches or larger.

Via www.hyundai.com