New EV motor invention could cut 1,000 pounds from future vehicles, making them much lighter while boosting their range
A new in-wheel motor for electric vehicles (EVs) delivers enormous torque in a lightweight package, its developers say.
The engine – made by YASA, a Mercedes-Benz subsidiary that also supplies engines to Ferrari – weighs just 28 pounds (12.7 kilograms) but can develop up to 1,000 horsepower at a time or a sustained output of 469 to 536 horsepower over longer durations. This new mark breaks YASA’s previous unofficial record, a 29-pound engine producing 738 horsepower, company representatives said in a statement. statement.
The ability to pack so much power into such a compact and lightweight engine is due in part to YASA’s axial flow technology. Traditional radial flux motors are longer, tube-shaped structures with a stator (the stationary part of a motor that creates a magnetic field used to produce motion) surrounding a cylindrical rotor. A magnetic field passes 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 passes along the axis parallel to the shaft (hence its name). Axial flow technology allows for much smaller designs than traditional radial designs, according to YASA.
Much lighter electric vehicles in the future
The company emphasized that the design is scalable and does not rely on any rare or exotic materials to function.
The design also paves the way for massive weight reduction in electric vehicle design. YASA said deploying in-wheel motors instead of traditional power and transmission could save about 440 pounds (200 kg). And for vehicles designed from the ground up to incorporate the new engine, the savings could be closer to 1,100 pounds (500 kg).
This is partly because the system also incorporates advanced regenerative braking, the process by which electric vehicles capture energy that would normally be lost as heat when braking and use it to recharge the battery.
Instead of energy being derived from the battery to turn the wheels, energy from the wheels is captured to turn the motor, which generates electricity rather than consuming it. The motor resists rotation while generating power, slowing the car and powering the battery. YASA claims that effective regenerative braking could reduce the need for traditional friction brakes, saving weight and space.
While the current iteration is clearly geared toward 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, lighter components. Reducing the space required for traditional powertrain components also offers manufacturers the opportunity to streamline aerodynamics or provide more interior space for cargo or passengers.
