Nidec's prototype of a traction motor is designed to be fitted inside the wheel hubs of electric vehicles (EVs). Commonly, regular EV traction motors occupy the engine compartment. In-wheel motors, as their name implies, are incorporated directly into the wheels of the automobile.
Benefits of this set-up include higher efficiency because of driving the wheels directly and bypassing the need for conventional power transmission mechanisms. In turn, this allows for lighter and more compact designs. Additionally, independent control of the wheels opens the possibility of making further improvements to electronic stability control and traction control systems.
Notable features of the in-wheel motor prototype are its high power and torque density and its lightweight properties. The prototype consists of a motor with integrated reduction gears and an oil cooling system. By leveraging the technology developed for the soon-to-be-mass-produced E-Axle, a single in-wheel motor can achieve a power output of over 100 kW (135 PS). That’s equivalent to an 1,800-cc class gasoline engine—while weighing 32 kg and being compact enough to fit inside a 20-inch wheel.
The motor is compatible with all the common car layouts: RWD, FWD and 4WD. The company aims to start mass-producing the motor around 2023. For more details, visit Nidec.