Car enthusiasts lament the commoditization of propulsion. In the past, motor enthusiasts would have chosen a BMW for its sonorous inline six-cylinder engine or a Mercedes-AMG for its thunderous V8. Now many believe that distinctiveness is rapidly diminishing. Electric cars can provide crazy, quiet thrust, but a common complaint is that they are mostly indistinguishable by the character of their drivetrains.
Car manufacturers worry about this too. Their engineering DNA is less evident in the era of electric vehicles, making them more reliant on design, brand power and other types of technology to differentiate their cars and retain their customers. There’s no point in trying to out-power the competition when the fastest Teslas and Lucids already have so much more than you’ll ever be able to deploy on public roads. More is not better when you already have too much.
But soon there will be a choice again: between the conventional radial flux motors that have powered almost every electric vehicle so far and something radically different.
Axial flux motors won’t necessarily offer more power, but they are so much lighter and smaller that their proponents say they have the potential to transform almost every other key measure of an electric vehicle’s performance and the entire architecture of a car designed around them. .
When fitting axial flux motors At wheels, spaces in a car’s body currently occupied by motors could be largely unoccupied, clearing the way for more batteries, people or things, and allowing the kind of design exuberance that electric vehicles have long promised. time but which they have never fulfilled.
More importantly, this new engine design could help address the growing public backlash against expensive and overweight electric vehicles. They could reduce the weight of a typical electric vehicle by around 200 kilograms (440 pounds), half in the motors themselves and the other half through the mass composition effect that, as a result, allows the weight of other systems, such as batteries and brakes. .
By sending mass into a virtuous downward spiral, automakers could increase range, lower costs and perhaps even preserve the agile handling of lightweight cars, which enthusiasts also worry could disappear with the arrival of the electric vehicles.
Flow capacity
The principle is not new. The axial flux motor was first demonstrated by Michael Faraday in 1821, but in the intervening two centuries no one had figured out how to reliably mass produce one.
British academic Tim Woolmer, however, likes a challenge. He dedicated his PhD at Oxford to designing the optimal motor for an electric car. He decided that an axial-flux engine would make more sense than the nearly ubiquitous and easy-to-mass-produce radial-flux design. But not only had the chosen design barely left the lab in almost 200 years, there was simply no market for it when it started in 2005: GM’s. EV1 It had been in the can for a long time and the Tesla Roadster was still three years away.
In an axial flux “pancake” motor, the stator (the stationary part of an electric motor) and rotors are discs, placed side by side less than a millimeter apart, the flux flows through the stator axially or parallel to the axis, and acting on the permanent magnets of the rotors on each side to rotate them.