The new in-wheel motor for electric vehicles (EVs) delivers enormous torque at low weight, according to its developers.
The engine, made by YASA, a subsidiary of Mercedes-Benz that also supplies engines to Ferrari, weighs only 28 pounds (12.7 kg) but can produce up to 1,000 horsepower at a time or a sustained output of 469 to 536 hp. during long-term work. This new brand breaks YASA's previous unofficial record of a 29-pound engine producing 738 horsepower, company officials said in a release. statement.
The ability to pack so much power into such a compact and lightweight engine is due in part to YASA's axial flux technology. Traditional radial flux motors are longer tubular structures with a stator, the stationary part of the motor that creates magnetic field used to create movement around a cylindrical rotor. The magnetic field is transmitted perpendicular to the shaft through the cylinder to rotate the rotor.
In contrast, an axial flux motor is more like a pancake with a disc-shaped rotor and stator. The magnetic flux runs along an axis parallel to the shaft (hence the name). According to YASA, axial flow technology allows for much smaller structures than traditional radial designs.
Much lighter electric vehicles in the future
The company emphasized that the design is scalable and does not require the use of any rare or exotic materials to function.
The design also paves the way for significant weight savings in electric vehicle design. YASA said using in-wheel motors instead of a traditional powertrain and transmission could save about 440 pounds (200 kg). And for vehicles designed from the ground up to accommodate a new engine, the savings could be about 1,100 pounds (500 kg).
That's partly because the system also includes advanced regenerative braking, a process by which electric vehicles capture energy that would normally be lost as heat during braking and use it to recharge the battery.
Instead of energy from the battery being shunted to turn the wheels, energy from the wheels is captured to turn the motor, which generates electricity rather than consuming it. The motor resists turning, generating energy, thereby slowing the car and powering the battery. YASA claims that effective regenerative braking can reduce the need for traditional friction brakes, saving both weight and space.
While the current version is clearly aimed at high-performance electric vehicles and supercars, axial flux motor technology opens the door to longer-range electric vehicles capable of generating more power with fewer and lighter components. Reducing the space required for traditional powertrain components also gives manufacturers the opportunity to optimize aerodynamics or provide more interior space for cargo or passengers.
