The Axial Flux Motor: A Guide to Pancake Power

An axial flux motor is a type of electric motor where the magnetic flux travels parallel to the axis of rotation. Imagine a flat, disc-shaped motor, and you're pretty much there. This "pancake" design is a world away from the common radial flux motor, where the flux radiates outwards from the centre, much like a traditional tin can. This fundamental difference in architecture gives it a huge advantage in power and torque density for its size.

Right then, let's cut through the jargon. You've likely heard the term "axial flux motor" being bandied about, probably by someone trying to sound like they know their stuff at a car meet. It sounds fiendishly complicated, but the concept is actually quite straightforward. Most electric cars on the road today use what’s known as a radial flux motor . Picture a chunky tin can spinning on its side – that’s your standard EV motor in a nutshell.

The axial flux motor, however, completely rips up that design. Instead of a long cylinder, it’s shaped more like a stack of pancakes. It’s flat, compact, and packs an incredible punch for its weight. This isn't just a quirky design choice; it fundamentally changes how the motor creates force and puts power to the road.

This diagram offers a clear visual breakdown of the two motor concepts.

As you can see, the core difference is the direction of the magnetic field. This one change dictates the motor's entire shape, size, and performance profile.

So, why does the shape make such a difference? In a radial 'tin can' motor, the magnetic flux travels outwards from the central rotor to the surrounding stator. It's a reliable, well-understood design, but it leads to a longer and heavier motor. A lot of that bulk comes from the stator yoke—a hefty chunk of metal that's necessary to complete the magnetic circuit but doesn't actually help produce torque. It's essentially dead weight.

The axial 'pancake' motor takes a different tack. Here, the magnetic flux travels along the axis of rotation—hence 'axial'—across flat, disc-shaped rotors and stators. This creates a much shorter, more direct path for the magnetic force to do its work.

This clever design philosophy has some brilliant consequences for electric vehicles:

• Higher Power Density: You get more power from a smaller, lighter package. This is the holy grail for performance cars, where every kilogramme counts.
• Superior Torque: The flat discs allow for a larger diameter where the magnets and coils interact. It’s a bit like using a longer spanner to turn a stubborn bolt – you get more turning force. The result is instant, massive torque.
• Compact Form Factor: Its flat shape opens up creative packaging options, like fitting a motor directly inside a wheel hub or building incredibly slim powertrain units.

In essence, the axial flux motor is a more elegant and efficient way to build an electric motor. It trims the fat, focusing purely on the components needed to generate performance. This is precisely why it’s graduating from a lab experiment to become the tech of choice for hypercar manufacturers and, before long, maybe even the car on your driveway.

To make it even clearer, here’s a no-nonsense breakdown of how the pancake stacks up against the traditional tin can.

As you can see, while the radial flux motor is the established workhorse, the axial flux design offers some compelling advantages, especially when performance and packaging are top priorities.

So, it's shaped like a pancake. Big deal, right? Absolutely. That seemingly simple design choice is a complete game-changer for electric vehicles, and it’s all down to a few key performance metrics that genuinely matter when you're behind the wheel. We're not talking marketing fluff here; we’re talking proper engineering advantages.

The two most important terms to get your head around are power density and torque density . In simple terms, this is about how much grunt you can squeeze out of a motor of a certain size and weight. A motor with high power density gives you more shove without adding more bulk.

This is precisely where the axial flux motor trounces its radial cousins. Because of its short, direct magnetic path and clever, yoke-less design, it can be significantly smaller and lighter for the same power output. Think of it as the difference between a heavyweight boxer and a featherweight martial artist—both pack a punch, but one is far more agile and efficient.

This superior power density has a massive knock-on effect on vehicle design. When the motor is lighter, other components can be too: the subframe it's mounted on, the suspension holding it up, even the brakes needed to stop it. It creates a virtuous circle of weight reduction, leading to a car that's not just faster in a straight line, but nimbler and more responsive through the corners.

The practical benefits are enormous:

• Blistering Acceleration: High torque density means instant, neck-snapping acceleration from a standstill.
• Improved Handling: Less weight, particularly unsprung weight if motors are placed near the wheels, makes for a much more engaging drive.
• Increased Range: A lighter car requires less energy to move, stretching every last electron from the battery pack.

This is why hypercar manufacturers, who obsess over every single gram, are ditching the old soup-can-style motors. They need the most performance from the smallest possible package, and the pancake design delivers exactly that.

Another often-overlooked but critical advantage is cooling. Traditional radial motors have their heat-generating components buried deep inside the 'tin can', making it a real challenge to get the heat out effectively. The flat, open structure of an axial flux motor, however, gives it a much larger surface area, making it far easier to keep cool.

This superior thermal management is a massive deal. Better cooling means the motor can run at its peak for longer without overheating—a phenomenon known as thermal throttling, which can seriously sap power during a track day or a spirited B-road blast.

In fact, some analyses show their design offers 30% to 40% better cooling than conventional motors. This efficiency, combined with their compact nature, is enabling powertrains that are 20-30% lighter than older designs, a crucial factor in high-performance applications. You can find more insights about these motor market trends in recent industry reports. It's why you see them not just in cars, but in high-powered drones and other demanding bits of kit where performance and reliability are non-negotiable.

Right, let's get down to brass tacks. If axial flux motors were the perfect, no-compromise solution for electric cars, every EV on the road would already have one. But the real world, with its inconvenient truths about physics and economics, always has the final say. This technology comes with some serious trade-offs.

On one hand, you have a motor that’s ridiculously power-dense, weighs a fraction of its conventional rivals, and is generally more efficient across the board. Think of it as swapping a heavy, cast-iron engine block for a compact, high-performance racing unit – a much bigger kick from a much smaller package.

But on the other hand, there’s a rather large, expensive elephant in the room. Historically, building these "pancake" powerhouses at any real scale has been an absolute nightmare, sending costs into the stratosphere. It's time to cut through the marketing fluff and look at the unvarnished truth.

The main reason your family EV doesn't have an axial flux motor is pure manufacturing complexity. Building a standard radial motor is a well-oiled, highly automated process that we’ve been perfecting for decades. Assembling an axial flux motor, however, is a much more delicate and fussy affair.

The entire design hinges on the incredibly precise alignment of its flat stator and rotor discs. The air gap between them – that tiny space where all the magnetic magic happens – has to be perfectly uniform and often measures less than a millimetre . Any tiny deviation creates enormous magnetic forces that try to slam the discs together, which, as you can imagine, is a very bad thing.

This level of precision demands engineering and assembly processes that are simply a fortune to automate for mass production. Until very recently, it was a technology best suited to low-volume, high-performance applications where cost is a distant second to outright performance. We're talking hypercars and motorsport, not the weekly shop.

While the open "pancake" structure of an axial flux motor generally makes it easier to cool, there’s a catch. When you push these things to their absolute limits – think hypercar-levels of punishment – managing the immense heat they generate becomes a serious engineering headache.

The stator, being the stationary part packed tight with copper windings, is where most of the heat builds up. Pulling that thermal energy away efficiently from the flat, sandwiched components is a tricky problem to solve. The solution often involves complex liquid cooling channels and exotic materials, which just adds more cost and complexity to the equation. It's one thing to be efficient on a gentle cruise; it's quite another to survive a flat-out lap of the Nürburgring without melting into a puddle.

Despite all these hurdles, the fundamental advantages are just too compelling for the industry to ignore. The potential for lighter, more agile, and longer-range electric vehicles is simply massive. This is precisely why companies are now pouring millions into cracking the mass-manufacturing nut.

A few key developments are changing the game:

• Cost Reduction Through Automation: New, highly sophisticated automated assembly techniques are finally being developed to handle the precise alignment needed, with the goal of slashing production costs.
• Material Innovation: Intense research is underway to find more effective and cheaper materials for both the permanent magnets and the advanced cooling systems.
• Economies of Scale: As more carmakers begin to adopt the technology, the sheer volume of production will inevitably start to drive down the cost per unit.

This transition won't happen overnight. But the journey from an eye-wateringly expensive piece of boutique engineering to a mainstream component has well and truly begun. The axial flux motor might still be in its pricey, exclusive phase, but its future looks decidedly more democratic.

This whole pancake motor business isn't just a concept dreamed up in a university lab. Real companies, staffed by engineers who get their hands dirty, are actually building these things. And some of them are doing it right here in Britain, which makes for a refreshing change. Consider this your field guide to the movers and shakers in the axial flux world.

You can't really talk about axial flux motors without mentioning the home-grown hero, YASA . What started as research at the University of Oxford quickly became the poster child for the technology. They proved these motors weren't just a theoretical curiosity but a genuine performance powerhouse, famously finding their way into hypercars like the Koenigsegg Regera.

Their success, naturally, didn't go unnoticed. In 2021, the automotive giant Mercedes-Benz swooped in and acquired the company. This wasn't just a casual purchase; it was a clear signal that the big German marques were finally taking this technology seriously for their next generation of high-performance AMG electric models.

While YASA often grabs the headlines, they're not the only ones in the game. The UK has quietly become something of a hub for this kind of high-end engineering. Other specialist firms are beavering away, supplying motors for everything from motorsport to aerospace applications.

This strong local presence is part of a much bigger European picture. By the end of 2021, Europe's axial flux motor market, with the UK as a key driver, commanded a whopping 37% global revenue share . This growth is being propelled by increasingly strict government mandates on EV adoption and energy efficiency. You can find more detail on the UK's role in the axial flux motor market.

Beyond our shores, other key players are making waves:

• Magnax (Traxial): This major Belgian player is aggressively pushing the boundaries of what these motors can do. They're focused on improving power density and perfecting manufacturing techniques to bring costs down.
• Saietta Group: Another British firm, Saietta is tackling the market from a different angle. They're making the technology more accessible for lighter vehicles like electric motorbikes and delivery vans, proving it's not just for hypercars.
• Legacy Automakers: Giants like Renault are also getting in on the act. They're developing their own axial flux designs for future models, aiming to make their EVs lighter and more efficient from the ground up.

So, which car brands have actually bolted these pancake powerhouses into something you can (at least theoretically) buy? For now, it remains an exclusive club—a who's who of the obscenely fast and expensive.

Ferrari is a key adopter, using axial flux technology in its SF90 Stradale and 296 GTB plug-in hybrids to provide a potent electric boost with a minimal weight penalty. Lamborghini has also integrated them into its new Revuelto hybrid. And as mentioned, Koenigsegg was an early pioneer, demonstrating the incredible performance potential.

The real shift will happen when this tech trickles down from the million-pound hypercar segment to more attainable performance cars. With Mercedes-AMG now having YASA in its arsenal and other major players investing heavily, it’s not a question of if , but when. The pancake revolution is well underway, even if it's starting at the very top of the automotive food chain.

Right, let's get to the important bit. All this talk of pancake power and hypercar performance is fascinating, but when can you actually get this technology in a car parked on your own driveway? You know, without needing to sell a kidney or win the lottery first. Let’s take a slightly cynical tour of the UK market and see where things stand.

At this exact moment, if you’re dead set on buying a brand-new car powered by an axial flux motor , your options are… limited. And by limited, I mean eye-wateringly expensive. We’re talking about the rarefied air of supercar royalty, a world of seven-figure price tags and two-year waiting lists.

The Ferrari SF90 Stradale and 296 GTB, the Lamborghini Revuelto—these are the current flag-bearers. They use compact axial flux units to provide immense electric power boosts without adding much weight. It’s brilliant engineering, but hardly relevant to anyone whose budget doesn’t stretch to a small private island.

So, is it all just a fantasy for the super-rich? Not quite. The technology is on a slow but steady march from the pit lane to the high street, and there are a few key factors accelerating its journey. The first, and most obvious, is the UK government’s looming ban on new petrol and diesel car sales.

This policy has lit a fire under manufacturers, forcing them to find every possible efficiency gain to make their EVs more appealing. An axial flux motor, with its potential for lighter cars and thus longer range, is an incredibly attractive solution. It’s no longer just a performance toy; it’s a genuine competitive advantage.

This trickle-down effect is already in motion. With Mercedes-Benz now owning YASA, it's a certainty we'll see this tech in their high-performance AMG models very soon. Renault is also publicly developing its own, more cost-effective axial flux motor, specifically aiming for its mainstream family cars.

While you can't walk into a showroom and buy a Ford Focus with an axial flux motor today, the next five years will see a significant shift. Here’s what to look out for:

• Premium Performance EVs: Expect to see the technology first in high-end electric saloons and SUVs from brands like Mercedes-AMG, Porsche, and potentially Jaguar. These cars will bridge the gap between hypercars and regular family transport.
• Specialist British Brands: Don't be surprised if smaller, more agile UK carmakers start adopting these motors to give their vehicles a performance edge. Their lower production volumes make them a perfect fit for this kind of advanced component.
• Commercial Vehicles: Oddly, the humble delivery van could be a dark horse. The high torque and compact size of an axial flux motor are ideal for urban logistics vehicles, where space and efficiency are paramount.

The shift is being supported by serious investment. Projects across Europe are focused on securing the supply chains for the rare-earth magnets these motors need and on perfecting the automated manufacturing that will finally bring costs down. The path is being laid for the pancake motor to become a common sight, even if it takes a few more years to get here.

The journey from a Koenigsegg to a family crossover is well and truly underway.

Right, you’ve stuck with us this far. You should now have a pretty good idea of why the axial flux motor is getting so much attention. But, as with anything this clever, a few questions are probably still rattling around in your head.

Let's tackle the common queries that always seem to pop up. Think of this as your cheat sheet for sounding like you know what you’re talking about next time the topic comes up. No more nodding along blankly; it’s time for some straight answers.

This is the big one, isn't it? If these ‘pancake’ motors are so brilliant, why isn't every electric car from a Renault Zoe to a Rolls-Royce Spectre already using one? The answer, as is often the case, comes down to two grimly predictable hurdles: manufacturing complexity and cold, hard cash.

For decades, carmakers have perfected the art of churning out traditional radial motors by the million. Their production lines are a well-oiled, highly automated machine. Building an axial flux motor, however, requires a level of precision that makes a Swiss watchmaker look clumsy. That tiny, consistent air gap between the stator and rotor discs is absolutely critical – get it wrong, and you’re in for a world of trouble.

This finicky assembly process has historically made them a nightmare to mass-produce cheaply. It's one thing to hand-build a few for a Koenigsegg, but quite another to make thousands a week for a family hatchback. Things are changing, though.

This is a common point of confusion, so let's clear it up. The short answer is no, an axial flux motor doesn't strictly need special ancillary kit. It will happily work with the same sort of batteries and inverters you’d find in any current EV.

However, that’s a bit like putting cheap remoulds on a Ferrari. Sure, the car will move, but you're leaving a huge amount of performance on the table. To truly unleash its potential, you need to pair it with the right gear.

The ideal partner for an axial flux motor is a high-performance inverter, typically one using silicon carbide (SiC) technology. These advanced inverters can switch power far more efficiently and at higher frequencies, allowing the motor to deliver its full potential for both power and efficiency. It’s not a mandatory requirement, but it’s essential if you want to wring out every last drop of performance.

While hypercars and screaming track weapons get all the attention, it’s a massive mistake to think axial flux motors are a one-trick pony. Their unique talents make them incredibly versatile, with applications that stretch far beyond just making cars go very, very fast.

The key thing to remember is that this technology is a perfect fit for any application where space is tight and weight is critical, but you still need a colossal amount of torque on demand. The high-performance car is just the most glamorous example.

Here are a few other places these powerhouse motors are starting to pop up:

• Heavy-Lift Drones: For industrial drones that need to lift heavy payloads, the high torque-to-weight ratio is a game-changer, allowing for longer flight times and bigger cargo.
• Electric Aircraft: In the burgeoning world of electric vertical take-off and landing (eVTOL) aircraft, every single gram counts. The compact, lightweight nature of these motors is essential.
• Marine Propulsion: Their flat shape makes them ideal for designing sleek, efficient electric outboard motors or integrated pod drives for boats.
• Advanced Robotics: For robots that need to be both powerful and nimble, the compact design allows for more sophisticated and less bulky joint mechanisms.

So, while you might first encounter the axial flux motor in a high-end EV, its influence is quietly spreading across numerous other industries. It's a fundamental improvement in electric motor design, proving its worth wherever power, weight, and size are the most important parts of the equation.

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