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# New Era of (Axial FLUX) Electric Motors

Hyper compact design at low-cost

## Market Situation

• Electric car market growth gets beyond expectations, and it continues the trends
• Electric motor and instrumentation will have huge demands in the next coming years

# Everyone is seeking for new technology to make next-gen electric motor:

SMALLER, LIGHTER, ECONOMIC, LOSSLESS, OPTIMIZED for collaborating systems, INDUSTRIALIZABLE, POWERFUL and COST-EFFICIENT

## Axial motor flow provides more torque and power per mass using the same amount of energy (current)

IT’S A SCIENCE FACT

## Better and Definitly Doable

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

##### A Global Mathematical Approach

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

‘E’/’0’

B-0

‘E’– ‘B/‘t’

‘B’‘0’ ‘0’ ‘E/‘t’

‘F’q (E-V-B)

‘Fe’S-J-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 rotor shape on the torque

What are the geometrical conditions that generate the same torque for those 2 geometries? Supposing we use the same magnetic materials (same magnets, same iron…. ) so we have the same magnetic pressure in the air gap on optimized machine.

where

##### 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:

For a given Torque, if we slightly adapt the axial motor flux, the overall volume and the mass of the final machine will be less than a radial-flux-one, even in cases where radial flux machine were 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! Indeed, implementing an axial flux machine over a radial one requires some adjustements, however the outcomes are significants: the global mass, the global volume and the global cost of the system will 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, radial flux motor actually occupies 99% of market share. Axial flow is a challenge to accomplish.

#### Very high linear speed

Demand on mechanical strength of incorporated magnets can be high

s

#### 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.

## WE HAVE SOLUTIONS

Conventional axial flux rotor provides high linear speed and heats up at high power output, the whole system becomes unstable and suffers from power loss. The need for an improved 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

#### Optimal Shape

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

Non-optimized stator is difficult to manufacture at high rate 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!
• Reduced cost

## You have a project?

15 + 2 =

#### office

Quercypole 2
Cambes, 46100 France

#### Hours

M-F: 8:30am – 5:45pm
S-S: Closed

(33) 0565101200