neptronix said:
ps, if you want more stator teeth, the magic pie is the way to go.
The leaf has a 51N46P design, but 56P would have same winding factor according to this simulator:
http://www.bavaria-direct.co.za/scheme/calculator/
So if someone would swap out the magents for 56pcs it would lower the kV by around 20% which means that it would have 20% less copper losses at given torque as the winding (turn count) stays the same
With more poles, the back iron in the rotor can be made thinner so they could reduce the weight.
However, the big downside of more poles would be the higher iron losses due to the higher ERPM, but in most sitauation where you need torque, the ETA would be higher.
Unfortunately, golden motor no longer publishes a dyno graph for the magic pie. The previous magic pie with 0.5mm lams barely hit 79% efficiency, whereas the power equivalent crystalyte HS35xx was boasting 84% peak efficiency with 0.5mm lams. My guess would be that it peaks at 87-89% efficiency these days.
I think this all goes back to the narrow stator and end turn losses problem.
...and also because of the high pole count which really needs thinnest laminations and other things like segmented magnets and back iron to keep iron losses low.
my 2C for a possible future Leafmotor:
- higher pole count for lowering copper losses and weight improvements on the rotor (like grin tech motor).
- thinner lams and segmented magnets to compensate for the higher iron losses
They even could make a 46P speed version and a 56P torque version, which would be really a torque version then and not just marketing bs**** as those lower kV versions are often advertised^^