Redefining The Boundaries of Power: How Axial Flux Motors Are Disrupting Traditional E-Drive Systems

As new energy vehicles, eVTOL aircraft, and even humanoid robots advance at breakneck speed, engineers face an eternal challenge: How to extract extreme power from a limited space?

Traditional radial flux motors (the familiar cylindrical machines) seem to be approaching their physical limits. At this moment, a next-generation core technology—the axial flux motor—is quietly taking center stage. Not only was it the original form of the electric motor invented by Faraday in 1821, but it is also today’s optimal solution to the paradox of “lightweight vs. high power.”

1. Anatomy: From “Cylindrical Can” to “Pancake” – A Form Factor Revolution

To understand the axial flux motor, the easiest way is through a visual comparison:

• Traditional radial motor: Shaped like a “cylindrical can.” The stator surrounds the rotor, and the magnetic flux radiates vertically along the radial direction (radius) of the rotor. This structure gives the machine a long axial length, making it bulky.

•  Axial flux motor: Shaped like a “pancake” or a “compact disc.” The stator and rotor are stacked flatly face-to-face, and the magnetic flux travels straight along the axial direction (parallel to the shaft). This face-to-face layout makes it inherently flat and compact.

If you think of a radial motor as a spinning barrel, an axial motor is like two grinding wheels rotating opposite each other.

2. Core Advantages: Smaller Yet Stronger

Why are high-end supercars (e.g., Ferrari, Mercedes-AMG) and aerospace giants abandoning traditional solutions for axial flux technology? The answer lies in its “game-changing” physical characteristics.

A. Ultra-High Power & Torque Density

Because the rotor diameter can be made larger than the stator (split ratio up to 100%) and the magnets are located farther from the rotational axis, the leverage principle (Torque = Force × Radius) means that for the same current input, it delivers significantly higher torque.
Data shows that advanced axial flux motors can achieve a torque density of 115 Nm/kg – comparable to a traditional V8 engine, but much lighter. Compared to conventional radial motors, power density typically improves by more than 30%, with some designs reaching 14.9 kW/kg.

B. Compact “Space Magic”

In vehicle chassis design, axial space is often at a premium. The extremely short axial length of an axial flux motor allows it to fit directly inside a wheel (as a hub motor) or be seamlessly embedded into gaps in the chassis. This frees up front and rear storage space and provides the physical foundation for distributed drive.

C. Extended Range via High Efficiency

With a shorter flux path and lower iron losses (hysteresis and eddy current losses), these motors often achieve efficiencies exceeding 96% or even 97%. For the same battery capacity, that translates directly into longer driving range.

3. Topologies: “Sandwich” Configurations of Rotors and Stators

Axial flux motors come in several forms. To balance performance and cooling, engineers have mainly developed two “sandwich” structures:

• Single-Rotor / Double-Stator (Middle rotor): The rotor sits between two stators. Magnetic attraction forces cancel each other, solving the unbalanced axial force issue. Robust and suitable for high-performance drives.

• Single-Stator / Double-Rotor (Middle stator): The stator sits between two rotors. This configuration has higher rotational inertia and makes it easier to cool the stator directly with oil, making it a favorite for extreme performance applications.

4. Manufacturing Challenges: Why Is It Taking Off Only Now?

Since the axial flux motor was invented in 1821 – earlier than the radial motor – why hasn’t it become mainstream for the past 200 years? The answer lies in process and material bottlenecks.

• Extreme precision requirements: Because of the planar air gap, even a slight rotor tilt or warpage can cause the rotor and stator to touch (“rubbing”). This imposes precision and assembly demands far more stringent than those for conventional motors.

• Heat dissipation difficulties: The compact “sandwich” structure means a small surface area for heat rejection; heat tends to accumulate rapidly. To solve this, manufacturers like YASA have introduced submerged oil cooling, directly immersing the stator windings in cooling oil.

• New materials revolution: Traditional silicon steel laminations are difficult to shape into the complex, non-circular geometries required by axial motors. The maturity of soft magnetic composites and amorphous alloys now enables 3D magnetic circuit design. Meanwhile, carbon-fiber wrapping technology addresses the issue of rotor integrity under high-speed centrifugal forces.

5. Applications: The Future Is Here

With these challenges gradually being overcome, axial flux motors are moving from laboratories to mass production:

• New energy vehicles: This is the largest growth market. Whether as the main traction motor in high-performance supercars or as a highly efficient generator in range-extender systems, axial flux motors are redefining e-drive performance. Manufacturers such as Zhixin Technology have announced plans to mass-produce relevant powertrains by 2026.

• Electric aviation: eVTOL aircraft are extremely weight-sensitive, demanding motor power densities exceeding 8 kW/kg. Axial flux motors are one of the few solutions capable of fulfilling the dream of flight.

• Humanoid robots: Robot joints require extremely high torque density and a flat shape – making axial flux motors ideal for actuator joints.

The axial flux motor is not merely a retro revival; it is a performance revolution driven by new materials and new processes. It shatters the century-old mindset that “motors must be long and cylindrical.”

For engineers and manufacturers, this is not just an update to the powertrain – it is a liberation of chassis architecture and overall vehicle design philosophy. With Mercedes-Benz acquiring YASA and supply chains in China aggressively entering the field, 2026 is poised to be the first year of large-scale axial flux motor adoption. The era of smaller, lighter, and more powerful e-drive systems is arriving at full speed.