Hub motor tuning

[avandalen]

I tried to make an overview of all parameters that are available to tune a hub motor. The goal is to increase the efficiency and power of a hub motor. Formulas are derived to show the relationships. The challenge is to build an efficient (> 90%) and light (<2kg) hub motor.

http://www.avdweb.nl/solar-bike/hub-motor/permanent-magnet-dc-hub-motor-tuning.html

Tuneable motor variables are for instance:

• Stronger magnets
  Improve the fill factor
  Increase the speed

The question is what is feasible in practice?

Here's another article, about the weight of hub motors. Generally, hub motors too heavy and too large for the power they deliver:

http://www.avdweb.nl/solar-bike/hub-motor/ebike-hub-motor-selection.html

If something is missing or wrong please let me know!

 

[fechter]

For best efficiency, you need to minimize losses wherever you can.

The iron laminations in the motor should be chosen for the least loss, which usually means using a special alloy and thinner laminations.

The gap between the rotor and stator plays an important role. This should be optimized. Too large or too small will increase losses.

Getting the timing optimized seems to be an issue with many cheap motors. Its not adjustable (easily) and probably should be.

The losses in the overall drive train need to be considered. A direct drive hub motor may be less efficient by itself, but has no gearing losses, so may be close to a more efficient geared motor.

 

[Miles]

Here's another article, about the weight of hub motors. Generally, hub motors too heavy and too large for the power they deliver:

http://www.avdweb.nl/solar-bike/hub-motor/ebike-hub-motor-selection.html

It would be more interesting to see a comparison of continuous torque density

 

[Miles]

Did you see this topic, Albert? http://www.endless-sphere.com/forums/viewtopic.php?f=30&t=23109

Also: http://www.endless-sphere.com/forums/viewtopic.php?f=30&t=25527

 

[avandalen]

Did you see this topic, Albert? http://www.endless-sphere.com/forums/viewtopic.php?f=30&t=23109

Also: http://www.endless-sphere.com/forums/viewtopic.php?f=30&t=25527

Miles, thanks for the Motor Excellence link. I have requested the factory for information!