Hyundai Mobis Develops In-Wheel System... "Electric Motor Inside Car Wheel"

Hyundai Mobis announced on the 19th that it has succeeded in developing a '4-wheel independent drive in-wheel system' where each wheel of the vehicle is directly controlled by a motor. The in-wheel system's core components are the drive motor and control technology. Hyundai Mobis developed all related technologies in-house. This is a new technology with no mass production cases worldwide. Hyundai Mobis is currently configuring a development vehicle based on the Ioniq 5 and is conducting reliability verification work for mass production together with Hyundai Motor Company.

The in-wheel system is applied to electrified vehicles. To respond to the electrification market, Hyundai Mobis began developing in-wheel technology in 2010. The in-wheel concept involves placing the electric vehicle powertrain inside the vehicle wheel, making the design process complicated. It is regarded as a technology with many challenges to overcome, such as securing power performance and durability.

The main features of the in-wheel system are ▲improved power efficiency and energy consumption ▲extended cruising range ▲enhanced driving performance ▲implementation of special motions. First, when the in-wheel system is applied to a vehicle, separate power transmission components such as the drive shaft (a mechanical part that transmits driving force to the wheels) are not required. This can maximize driving efficiency and is expected to improve energy consumption.

The e-corner system equipped with Hyundai Mobis' in-wheel technology. The e-corner system is an integrated solution that combines electronic steering, braking, and suspension technologies centered around the in-wheel. Photo by Hyundai Mobis

The in-wheel system also helps increase the driving range of electrified vehicles. Since the existing drive system is integrated inside the wheel, the space can be utilized to increase battery capacity. Because each of the four wheels is directly controlled by its own motor, the in-wheel system can efficiently distribute driving force to provide optimal cornering performance and vehicle posture control.

The 4-wheel in-wheel system developed by Hyundai Mobis can improve cornering performance through efficient torque distribution front, rear, left, and right, and achieve more than approximately 20% improvement in energy consumption. Applying the in-wheel system also enables the implementation of special motions such as zero-turn and crab driving.

The core technology of the Ioniq 5-based e-Corner system showcased by Hyundai Mobis at CES 2023 held in Las Vegas, USA, earlier this year can also be considered in-wheel technology. The e-Corner system is an integrated solution that combines electronic steering, braking, and suspension technologies centered on the in-wheel drive unit. Hyundai Mobis is currently developing the e-Corner system for actual vehicles and aims to complete development within the next five years.

Oh Heung-seop, Executive Vice President and Head of the Electrification BU at Hyundai Mobis, said, “We plan to complete durability and reliability development by the end of this year to enable actual mass production of the in-wheel system,” adding, “We will continue to enhance the technological completeness to respond to future mobility.”