The British company Yasa Motors, controlled by the Mercedes group, has developed an electric motor weighing just over 13 kilograms and delivering 738 horsepower, achieving a power-to-weight ratio of 56 horsepower per kilogram
That electric motors are optimal propulsion units for self-propelled vehicles is an indisputable fact. With equal power output, they are lighter and more compact than internal combustion engines, boast more than double the energy efficiency, and require almost no maintenance. Two confirmations of this come to mind. The first is the widespread—indeed monopolistic—use of electric motors wherever they can be continuously powered through dedicated lines. The second is the development in England of a unit weighing just over thirteen kilos, capable of delivering 543 kilowatts (about 738 horsepower), for a power-to-weight ratio of 56 hp/kg. This figure is more than double the industry benchmark of 20 hp/kg, and even surpasses the current sector record held by the Australian company Equipmake with its “Hpm-400” motor/inverter system designed for aerospace applications, which has a ratio of 54 hp/kg.
The author of this new achievement is the British company Yasa Motors, a Mercedes-Benz subsidiary specialized in the design and production of axial flux electric motors. The company stressed that the performance has not yet been officially certified by external bodies, but it nevertheless represents a historic milestone in electric motor engineering—especially considering that the prototype was built without exotic materials or 3D printing. Should the result be officially confirmed and replicated in mass-produced units, Yasa Motors expects to manufacture up to 50,000 motors per year, initially intended for use in supercars by AMG, Ferrari, Lamborghini, and Mercedes—all already Yasa Motors clients
Axial is Better
Axial flux electric motors, also known as disc motors, are units in which the magnetic flux moves parallel to the axis of rotation, rather than radially as in traditional motors. Compared to radial technology, axial flux offers several advantages: higher torque density, a more compact and lighter design, and greater efficiency. These motors are also easily scalable and, if properly cooled, capable of handling heavy loads. Unsurprisingly, they are used in today’s most high-performance hybrid supercars, including the Ferrari SF90 Stradale.
On the downside, challenges include the difficulty of manufacturing magnet-free motors, the rotor diameter which prevents exceeding 10,000 rpm, and the need for sophisticated and costly cooling solutions. Nonetheless, axial flux electric motors are undoubtedly set to become the standard in all applications demanding compact and high-performance units.
Translation with ChatGPT
