Spicerack
10 kW
Ok, so here’s my story. I cooked my poor little MAC by putting way too many amps through it. It still works, but gets hot real quick so whilst waiting for another stator to rebuild it, I decided to try oil cooling as a band aid solution.
Without oil, the motor gets up to 120 celcius and is rising by 10kilometers (6 miles). This is running 60V, 20amps. In real terms it tends to be cruising at WOT around 1300W on the CA.
I sealed the motor up with silicone on the covers, drilled a little pressure relief vent hole hear the axle on one of the covers and put 1-200ml of transmission fluid in it. I didn’t want too much as it would leak out of the axle- which I also sealed as best as I could from the outside. It’s a very basic closed oil-splash system just like most lawnmower engines.
I rode it to work today, which is 22km. The hottest it got was around 90 celcius. It was very interesting to see the temperature on the windings go up by a degree or two a second whilst accelerating from standstill, then drop almost as fast once up to speed and on WOT. Most of the time it was running at 75 celcius.
It was also very interesting to note that cruising at say ¾ throttle resulted in the temps going up- but as soon as I went to WOT at the same speed, the temperature started coming down again and quite rapidly.
I know that people have always said that it’s better to run at WOT but have never seen the results as plain as this today.
So there you have it. A simple oil cooling setup can drastically cool your motor- in my case although my windings are knackered, at least I can still use it until the new bits turn up. I would definitely recommend this over air cooling- certainly for the geared hubs as it takes the heat to the outer covers of the hub.
Without oil, the motor gets up to 120 celcius and is rising by 10kilometers (6 miles). This is running 60V, 20amps. In real terms it tends to be cruising at WOT around 1300W on the CA.
I sealed the motor up with silicone on the covers, drilled a little pressure relief vent hole hear the axle on one of the covers and put 1-200ml of transmission fluid in it. I didn’t want too much as it would leak out of the axle- which I also sealed as best as I could from the outside. It’s a very basic closed oil-splash system just like most lawnmower engines.
I rode it to work today, which is 22km. The hottest it got was around 90 celcius. It was very interesting to see the temperature on the windings go up by a degree or two a second whilst accelerating from standstill, then drop almost as fast once up to speed and on WOT. Most of the time it was running at 75 celcius.
It was also very interesting to note that cruising at say ¾ throttle resulted in the temps going up- but as soon as I went to WOT at the same speed, the temperature started coming down again and quite rapidly.
I know that people have always said that it’s better to run at WOT but have never seen the results as plain as this today.
So there you have it. A simple oil cooling setup can drastically cool your motor- in my case although my windings are knackered, at least I can still use it until the new bits turn up. I would definitely recommend this over air cooling- certainly for the geared hubs as it takes the heat to the outer covers of the hub.