Overheating Ezee vs Bafang Bpm/Cst

[1boris]

From ebikes.ca simulator it shows that the Ezee motor can take about twice the time of an Bpm/Cst motor before it overheats.Why is that?.The motors are about the same size.Both have 22mm stator widht.Is the simulator correct?

 

[motomech]

Maybe because Justin constructed the sim :lol:
Compare the BPM to the MACs.

 

[spinningmagnets]

The eZee has thinner laminations, which produce less eddy-current waste-heat. that may not sound like much, but geared hubs have a 5:1 ratio between the motor RPMs and the wheel RPMs, so a 360 RPM 26 inch wheel at 28-MPH would have a motor spinning at 1800 RPMs.

If thinner laminations help on direct drive hubmotors, they help 5 times as much on the geared hubmotors.

That being said, you can take the cheaper BPM geared hub, swap-in fatter phase wires, add ATF while sealing the sidpelate edges with goop, add a tiny sideplate vent, use a sensorless 12-FETcontroller...and it will likely run on 2000W fairly reliably.

https://endless-sphere.com/forums/viewtopic.php?f=16&t=51237

 

[rumme]

The eZee has thinner laminations, which produce less eddy-current waste-heat. that may not sound like much, but geared hubs have a 5:1 ratio between the motor RPMs and the wheel RPMs, so a 360 RPM 26 inch wheel at 28-MPH would have a motor spinning at 1800 RPMs.

If thinner laminations help on direct drive hubmotors, they help 5 times as much on the geared hubmotors.

That being said, you can take the cheaper BPM geared hub, swap-in fatter phase wires, add ATF while sealing the sidpelate edges with goop, add a tiny sideplate vent, use a sensorless 12-FETcontroller...and it will likely run on 2000W fairly reliably.

https://endless-sphere.com/forums/viewtopic.php?f=16&t=51237

I'm gonna chime in on this, since I experimented with it. I used a Bafang 750 watt geared hub motor, filled it with ATF fluid and pumped around 2300 watts max into it. I was unhappy with its performance and also the motor got very hot. The problem is the ATF fluid, still traps the heat inside the motor casing . After experimenting with numerous cooling mods, I still think several properly placed air holes in the side casing, is the best method Ive done. It allows the heat to actually escape the inside of the hub motor, quicker , better and with no mess seen with ATF fluid.