FUTURE AHEAD +33 (0)5 65 10 12 00

New Era of (Axial Flux) Electric Motors

Hyper compact design at low-cost

Market Situation

  • Electric car market growth gets beyond the expectation, and it continues the trends

  • Electric motor and instrumentation have huge demands in coming years

Everyone are seeking new technology that can make electric motor:


Axial motor flow can provide more torque and power per mass using the same amount energy (current), while smaller


Better and Feasible

Axial motor flow is in any aspects better than radial flow motor

A Global Mathematical Approach

Let us consider a general case in which a moving charge
is submitted to an Electromagnetic Field (E, B )



‘E’– ‘B/‘t’

‘B’‘0’ ‘0’ ‘E/‘t’

‘F’q (E-V-B)


This is the (E, B)force acting on the moving part per unit volume

Field Electromagnetic (Green) exchanges in the Radial Air Gap

Field Electromagnetic (Green) exchanges in the Axial Air Gap

In any case of a Cylindrical Electric Machine (either radial or axial topology), the force depends only on the interaction between the magnetic field produced by the rotor and the stator.

Influence of the geometry

Influence of the geometry

of the rotor on the

value of the torque

Radial Case

Axial Case


What are the geometrical conditions that generate the same torque for the 2 geometries? Supposing we use the same



(same magnets, same iron…. ) so we have the same



in the air gap on optimized machine.


Conclusions on Expression

The geometrical variation generates a higher torque for an axial-flux machine than a radial-one, in other Words, for a given required torque, we can use less magnets and less windings for the axial-flux machine as the magnetic pressure can be diminished.

Case study

The real meaning of this formula, is that For a given Torque

, if we canslightly adapt the axial motor flow, the overall volume and the mass of final machine will be less

than a radial-flux-One, even in cases where radial flow machine are considered better!

Case One

From radial motor to axial motor, if d5′ could be 10 higher, we can achieve L5′ divided by 2,and save 30 volume.

Case Two

From radial motor to axial motor, though d6′ is 50′ higher, we can achieve L6′ divided by 3 even 4,still save 30 volume.

The real Interest of an axial-Flux Machine lies in the fact that its torque produced requires less magnetic volume than a radial-flux machine. The mass of the machine will be lower in most applications! The other global parameter to consider is the centrifugal effect: experimental background and studies show that the range speeds of an axial-flux machine is about 15,000 rpm for a diameter of 300 mm

Global system must be analyzed in order to achieve this improvement, but It worth it! Implementing an axial flux machine over a radial one, even some adjustment may be needed, the outcomes are still significant as the global Mass, the global Volume and the global cost of the system can be dramatically reduced.

That is why axial flux machine is better than radial flux machine in most cases scientifically speaking.

Axial Flux Motor: Why So Late?

Despite the benefits on axial flow, at present radial flux motor occupies 99% of market share, as axial flow is challenging

Very high linear speed

Demand on mechanical strength of incorporated magnets can be high


Rotor heats up

Cooling system complex and expensive, Magnet can be demagnetized

Stator structure non-optimized

  • Stator is difficult to manufacture at high cadence on production line
  • Assembling process should be easily industrialized in production.

Future Ahead


Better rotor

Conventional axial rotor flow provides high linear speed for some parts on it, and heats up at high power output, the whole system becomes unstable or even under-power. The need for a better rotor design is obvious.

Composite material

  • Easy to manufacture
  • No excited heat from magnetic field
  • Strong and durable

Inspired from nature

  • Honeycomb grid hold magnet
  • No heat, no loss!
  • Verified and tested in prototype

Shape naturally

  • Egg magnets fit perfectly in the grid
  • No heat, no demagnetization
  • Verified in simulation

Better stator

Non-optimized stator is difficult to manufacture at high cadence on production line.

Modular Structure

  • Easy to proceed winding
  • Maintain mechanic performance
  • Suitable for mass production

Guided Alignment

  • Remove magnetic force difference
  • No power loss
  • Easily implementation and operation

Two stators one rotor

  • Double excitement on rotor
  • Less magnets for same performance!
  • Cost reduce

You have a project?

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Quercypole 2
Cambes, 46100 France


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