An engineering deep dive into axial flux motors. Learn about torque density, 10kW/kg power density, and the stackable AXM architecture by Beyond Motors.
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An engineering deep dive into axial flux motors. Learn about torque density, 10kW/kg power density, and the stackable AXM architecture by Beyond Motors.
For decades, the radial flux motor has been the undisputed "workhorse" of the industry. However, as the 2026 propulsion landscape shifts toward the rigorous demands of eVTOLs, high-performance marine vessels, and long-range EVs, the traditional radial architecture is hitting a physical ceiling.
At Beyond Motors, we believe that the transition to Axial Flux motor technology is not just an upgrade—it is a fundamental architectural shift. For CTOs and lead engineers, understanding the "why" behind this transition is essential to maintaining a competitive edge in power density and system efficiency.
The primary differentiator between these two architectures is the direction of the magnetic flux path. In a radial motor, flux travels perpendicularly to the axis of rotation. In an axial flux machine, the flux travels parallel to the axis.
In radial motors, torque is proportional to the square of the diameter multiplied by the length ($T \propto D^2 \times L$). In an axial flux motor, however, torque is proportional to the cube of the diameter ($T \propto D^3$).
Because the active magnetic material is positioned at a greater average radius from the center, the lever arm is inherently longer. This geometric advantage allows the Beyond Motors AXM series to deliver 30-40% higher torque density than radial counterparts of the same mass.
By utilizing a grain-oriented electrical steel or yokeless segment armature (YASA) topology, axial flux designs significantly reduce the iron mass in the stator. This reduction in "dead weight" is what enables our high-performance e-motors to achieve a power-to-weight ratio of up to 10 kW/kg, a benchmark that was once considered impossible for production-grade machinery.
One of the most persistent challenges for engineers is the "thermal trap" inherent in radial motors, where heat-generating windings are buried deep within the stator.
We have engineered a patented water cooling system that addresses this head-on. By placing the cooling interface in direct proximity to the stator windings, we maximize heat extraction. This allows for:
For engineers, scalability usually means a complete redesign of the powertrain. Beyond Motors has simplified this through a fully stackable design.
The hollow-center architecture of our rotors allows for an internally splined hub. This means you can stack up to three full motors on a single shaft to multiply torque and power by 3x—without increasing the diameter of the motor housing. Whether you are scaling from a single-seat UAV to a heavy-lift cargo drone, or a luxury sedan to a heavy-duty truck, the integration process remains consistent.
If your project requires custom specs, sizing, or specific project requirements, this modularity ensures that the R&D cycle is measured in weeks, not years.
The industry data is clear. As battery energy density increases, the motor becomes the new bottleneck for system weight.
The shift toward axial flux is driven by the immutable laws of physics. For projects where volume is a premium and weight is the enemy, the Beyond Motors AXM series provides the architectural freedom to build faster, lighter, and more efficient systems.
Are you ready to simulate your next drivetrain?We invite you to use the Beyond Motors Configurator to input your specific torque and RPM requirements and receive a personalized data sheet for your project.
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