What kind of hub motor is this?

Today I decided to open up my "500w" ebay hub motor to coat the stator in some SPRAYON EL601 to waterproof it. I live in Michigan, so water getting into the motor is a real concern. But while we are in here, I would like some feedback about what kind of motor this actually is. Is this a 9C, golden motor, or some generic thing?

A little background on my bikes specs:

52v 20AH battery built from old power tool cells.

Gary fisher mountain bike

36v "500w" ebay hub motor kit.

With zero modifications to the wiring, I currently run this hub motor at 1500w continuously. I performed a shunt mod on the stock controller to get me 30A and replaced the capacitors so I could go to a 52v battery (FETs were already rated at 75v). So far i've done a few hundred miles on 1500w with no ill effects as far as I can see.

Anyway here's what we got. The hub motor has written on it "9x6" and "12" (or is it 9x6 and 21?). I'm not sure what these numbers mean so enlighten me.

First the link to the ebay page:
https://www.ebay.com/itm/26-Rear-Wheel-36V-500W-Electric-Bicycle-Ebike-Conversion-Kit-Hub-Motor/321679232957?epid=1580882108&hash=item4ae5938fbd:g:OikAAOSwb9BatNFP

Pictures:



Questions:

Since I have been running this motor at 1500w, how far do you think we can go? Could I possibly run this hub motor at 2000 or even 3000w at 72v if I drilled holes in the cover places or added statorade to the motor before i close the thing back in again (I can't do both because then the statorade will just make it's way out through the holes)?

Also which is better for cooling? Statorade or drilling holes in the cover?

Since I already have the motor open, I would like to beef up the phase wires to 12AWG and add either statorade or vent holes Just in case I want to run this thing at even higher power later on. Knowing me, I probably will inevitably do just that, so might as well prepare for the future now.

One more thing:

I believe statorade is just ferrofluid. Couldn't I just buy a can of ferrofluid from amazon for less money than the statorade? It seems like it's the same thing.

https://www.amazon.com/CMS-Magnetics-Magnetic-Ferrofluid-Projects/dp/B000VAZKQI/ref=sr_1_fkmr0_2?s=industrial&ie=UTF8&qid=1525505850&sr=1-2-fkmr0&keywords=10mm+ferrofluid

Its a six turn "9 continent type" motor. 6 turn is the semi fast wind, vs the 7 turn wind that will be legal for the 20 mph rule in the US, when run 36v.

Who knows who made the motor, 9 continent type just came into use because at one point Grin was using that brand, and it was considered a better finished product than some of the other brands. There are literally thousands of factories in china making copies of the same basic design, with 28 mm wide stator.

I have no experience with statoraide, but a few relatively small holes will help the motor cool when you stop. I have found that when you cook the halls in your motor, its when you stop and the motor temp spikes like hell because you are not going 35 mph anymore. Letting that hot air convect out through small ish holes when you stop helps.

But at 1500w, unless your total load is over 400 pounds, or you are hammering it with many many stops and corners, I see no need for cooling that motor. At full gallop, it will actually have a fairly low load, and easily go 10 miles at a time non stop, full boogie.

Go to 72v 40 amps, then that motor will struggle, and need to stop at 8-10 miles, and need the holes to cool the halls.

The one thing I like about holes, even tiny ones to let water out, they also let you smell the winding when you stop. Hot butter smell ok, burnt popcorn smell bad.

Beef up your wires, but outside the hub. The shorter length of the wire inside will resist less than the whole wire did, and the fat wire outside will heat sink the little bit left inside.

If you are going big, budget for the bigger motor you need. meanwhile have fun till this one melts.

As long as the motor is apart, buy a temp sensor and insert it inside the hub near the stator (the hottest part), regardless of whatever else you do. Id recommend trying Statorade first, because once you cut ventilation holes into the sideplates, you might as well get a new hubmotor if you want to try something else.

The generic 28mm wide stator hubmotors like this usually have the more affordable 0.50mm thick laminations (I enlarged the pic you provided and counted, and 0.35mm lams run cooler), so there will be some eddy-current waste-heat at higher RPM's. How bad? it depends, and that's why the temp sensor will tell you everything you need to know during experiments. My hills might not be as frequent or as steep as your hills, so...

Wire is pretty cheap, and as long as you have the motor apart, maybe boost the thickness of the phase wires as much as possible (even a little will help, maybe go to 12-ga?) and just as dogman said...as soon as the wires exit the axle, "fatten them up" even more.

"Temp sensor that's too cool not to share" (Auraslip, 4 pages)
https://endless-sphere.com/forums/viewtopic.php?f=1&t=25502

"DIY 10awg phase leads through axle in 9C hubmotor." (liveforphysics, 5 pages)
https://endless-sphere.com/forums/viewtopic.php?f=2&t=14580

I too, find ferrofluid better than cooling holes. Dissipation of the heat is good, and it doesn’t let salted slush in during the winter, or muddy water in the summer.

Many on ES, had got away feeding those small motors 10 Kw bursts in acceleration.

Many stops and starts and long steep hills will heat up the motor very fast cruising on a flat Street is a lot easier on a motor plus how much luggage you're caring and how much you weigh. Yes those Motors are meltable. Next should a 35mm or 40mm stator motor

Thanks for the help everyone, a 10ml syringe of ferrofluid is currently on order from lunacycle as we speak.

My riding style is nearly all flat road. I basically never encounter hills here. I think the highest grade hill within a 50 mile radius is 1% where I live.

I met this dude who had a moped today and he smoked me in acceleration. Maybe now I can beat him after everything is said and done, who knows?

One more thing:

Ferrofluid + a hubsink apparently does wonders for cooling off hub motors. While I'm not willing to spend $70 on what is effectively just a chunk of aluminum, I do have plans to make my own. Maybe if the price was something like $25-35 shipped I would bite, but $70 is too much. I live near a scrap metal yard filled with bins and bins of aluminum heatsinks so if I cut those up and thermally glue them onto the hub motor, that might just work almost as well.

Expect to see more threads with questions later on. I live in Michigan where many people here (including bike shops) don't even know electric bikes exist, so this is my only option for support.

Up the voltage and the amps to 72v 40 amps, and you should be able to smoke just about any moped off the line. And that is about the practical limit of that motor, because of that lamination, it will start getting real hot if you push it higher rpm. Though as said, for a short enough duration, you can do more.

3000w will do er, right now you are running about 2000.

The fluid will help your run time to melt for sure, but not make the motor able to run efficient above 72v. Like I said, start saving for the big motor, and meanwhile have fun! Sounds like your typical ride won't melt it to me, even without ferro fluid or holes. It will get hot, but it can stand a lot. Just keep it under 250f inside.