In-wheel motor technology, also known as wheel-mounted motor technology, is characterized by integrating the power, transmission, and braking systems into the wheel hub, thus greatly simplifying the mechanical components of electric vehicles. In-wheel motor technology is not new; as early as 1900, Porsche was the first to manufacture an electric vehicle equipped with in-wheel motors in the front wheels. In the 1970s, this technology was applied in fields such as mining vehicles. For in-wheel motors used in passenger cars, Japanese manufacturers began research and development earlier and currently hold a leading position. International automotive giants, including GM and Toyota, have also ventured into this technology. Currently, some domestic Chinese automakers have also begun developing this technology.
For traditional vehicles, clutches, transmissions, drive shafts, differentials, and even transfer cases are all essential. These components are not only heavy and complex, making the vehicle's structure more intricate, but also require regular maintenance and have a high failure rate. However, in-wheel motors effectively solve this problem. While meeting current space requirements, future vehicles powered by in-wheel motors can be much smaller, helping to alleviate urban congestion and parking issues. Furthermore, independent in-wheel motors offer greater flexibility in driving the vehicle, enabling functions and driving characteristics that are difficult to achieve in traditional vehicles.
In-wheel motors significantly increase unsprung mass and wheel hub rotational inertia, which negatively impacts vehicle handling. Furthermore, in-wheel motors operate in harsh environments, exposed to water, dust, and other contaminants, requiring high levels of sealing and requiring separate design considerations for heat dissipation.
Currently, Ford Motor Company and auto parts manufacturer Schaeffler are jointly developing in-wheel motor drive technology, which they will use to create the first "rear-wheel drive" Fiesta.
