@Vito - have you guys followed the cooling threads of hub motors here on ES?
Some good news is coming. It seems Ferro Fluid will keep the magnetic oil (FF) stuck'd to the magnets. Even during motor rotations. Nice clean no-leak solution to give effective cooling to hubmotors without drilling holes into the side covers. Keeping the motor shielded and closed is good to prevent dirt, debris and water to get inside the motor.
I am so excited about the Ferro Fluid as cooling fluid for hubmotors and it seems the FF cools really good so that should mean longer lasting motors even when run @ higher power then standard. It seems FF will keep motor cool and thereby avoid demagnetization cause by overheating the hubmotor.
The reason for posting this in your thread is that I was thinking you could maybe check with your engineers to see if there is anything inside the QS motors that might react in a negative way on Ferro Fluid. I am thinking; adhesive, copper, magnets, stator lams, wire isolation, and of course the Hall sensors.
If you could check with them engineers if they have any knowledge of anything that might lead to early failure of parts do to contact with Ferro Fluid oil. And if they think contact with FF might lead to premature failure of any internals, will coating of the inside of the hub with the now well known red coating someone already has done one the internal help to better shield the motors internal components? Here is Roadrash's red internals:
I am thinking probably the only thing needed to remove vast amount of heat from hubmotors is flat black paint to aid radiation heat removal and Ferro Fluid oil inside the motor. And for me it seems that these steps taken will be well worth taken for those who plan on overvolting or dumping vast amount of current from controller during OVS for 25-30% extra top speed.
Read more about the latest tests (now done while running a home made wind tunnel to simulate real world air flow during rides) done here:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=48753&start=725#p1106508
An overview over how Ferro Fluid affects internal temperature of hubmotors:
Thx to Justin for the tedious work; testing, calibrating and more testing over and over again.