motor cooling

[Sharkboat]

I have only just begun to drive my trike and i decided it needs more power.

I started looking into additional cooling. It is a astro 3220 with a fan and open case. The Davinci Drive is aluminum and also absorbes and dissipates heat. So far i have only been running low power, 1000W and the motor doesn't even get warm. I want to take this motor to 10,000 W and beyond eventually, so planning for the future.

I figure i have 2 main options, liquid or air cooling. I have only looked into air cooling so far. I was thinking about adding a small copper heat-sink to the other half of the motor, not held by the reduction drive. Before adding the heat sink, it might be beneficial to remove the black paint on the can of the motor. This small insulation from the paint might be negligible. I was also thinking that a thin film of the heat-sink adhesive used in computers might help in-between the motor and the heat-sink. From the research i did, a matt or dull black paint, not thicker than 0.002 in. thick works best to covert the heat-sink. I also found research articles detailing the optimum fin spacing for different velocities. I also found an interesting article describing how adding a baffle around the heat sink increases the airflow to the back of the cylinder.

Fin info:
http://www.jstage.jst.go.jp/article/jsmeb/49/3/869/_pdf
Baffle info:
http://x-jets.com/Design_for_optimum_cooling_efficiency.pdf

The astro 3220 has a relatively low thermal mass to absorb the heat. Would that effect a decision to use either air or liquid cooling?
Pros and Cons of Air vs. Liquid?
I know air cooling will be lighter and more reliable. Liquid will be more expensive, but offer greater heat transfer.

 

[John in CR]

The Astro's are such small motors that the limited surface area is going to be your Achilles' Heel for air cooling.

 

[Sharkboat]

started reading a lot about water cooling. There is tons of info out there. The only commercial product for RC cars that i could find was tcs
http://www.tcscooling.com/order.html

It is really small and probably couldn't handle very much heat at all. The design isn't perfect and there is not enough info about it on their website. I think a custom set up would have to be used.

 

[lostrack]

I was wondering exactly the same thing this weekend!

Astro 3220 and davinci.

I think a heatsink will get snapped after regular use, if you're looking at the CPU cooler types.

Water cooling in a sleeve outside the motor may work well, you can always upgrade the motor from a pc overclocking kit?

 

[Thud]

I want to take this motor to 10,000 W and beyond eventually, so planning for the future.

That is a lofty goal for a motor only rated for 4.5kw cont.

Do you have info regarding the maximum amps before stator saturation? Pushing past that point will yeild zero return for performance. It is the 1st number you need to base the rest of the cooling calculations on.

This is really a huge step outside of that motors efficancy ranges. I do like the idea of active cooling for stressed applications (racing & experimenting) After that its counter intuitive for any thing other than fun.
Looking foward to the results.

 

[lostrack]

I want to take this motor to 10,000 W and beyond eventually, so planning for the future.

That is a lofty goal for a motor only rated for 4.5kw cont.

Do you have info regarding the maximum amps before stator saturation? Pushing past that point will yeild zero return for performance. It is the 1st number you need to base the rest of the cooling calculations on.

This is really a huge step outside of that motors efficancy ranges. I do like the idea of active cooling for stressed applications (racing & experimenting) After that its counter intuitive for any thing other than fun.
Looking foward to the results.

OP probably means peak values, I think you'd run out of road/gears with that value continuous. 10k is do-able on these motors under peak

If he does mean continuous, then yes, no heatsink will sort you out there. Get a bigger motor.

 

[lostrack]

Actually,

It is a astro 3220 with a fan and open case.

You're using the new fan cooled 3220? With holes and stuff?

I doubt you're going to get better cooling than that. They designed it specifically for that purpose -

To be honest, I'd stop there and if you need it to be cooler, change your riding style.

 

[Sharkboat]

I was thinking about what point of the vehicle would be the weakest link when increasing power. I think first, my battery capacity is way too small to supply that much power for any great length of time. Second, I will fry my 2 stock front disk breaks. After that, who knows. The motor temps might be the last thing i have to worry about.

I find the technology of cooling a motor very interesting.

 

[hjns]

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