Cooling Motors

[Sylvestre]

Hi,

I have question about the best way to cool motors.  The blue part is the motor and the black part on top of it is the fan.

Would it be better to enclose the motor with an aluminum shell so all the heat is contained and pulled through the fan?  OR Would it be better to keep the casing open (as it is now)?

Thanks

[waltr]

Does this setup cool the motor enough?
In that setup the air will not flow completely around the motor. Most of the cooling will be at the top of the motor and the air then gets diverted away from the motor so that there is little cooling on the bottom of the motor.
An enclosure that directs the air flow completely around the motor would be better.

[Sylvestre]

Does this setup cool the motor enough?

I have know way of knowing with the given specs the motor manufacturer gave.  The fan I picked out was one of the largest fans (in terms of CFM) surpluscenter.com offered.  102 CFM. 

An enclosure that directs the air flow completely around the motor would be better.

I'm not sure if I understand exactly what you mean by directs the airflow.  Is is what you mean?  (see image below)

[waltr]

That enclosure will help cool the motor better than no enclosure since all of the air flow is forced to stay close to the motor. In you first drawing most of the air will be deflected by the motor so that the lower sides and the bottom of the motor does not get air flow.


Any reason why you think the motor needs additional cooling?

[Sylvestre]

Alright thanks for the advice.  This motor is going to be operating in hot environments for a long duration.  That is why I decided it will need cooling

[jkerns]

I assume this is a brushless DC motor as commonly found in electric RC applications?

Remember that they do run a lot hotter at low speed /high current operating points than at higher speeds where the current is reduced.  They will run all day at full power if you let them spin quickly, but pull down the speed and they can overheat or overload the motor controller.

Forgive me if I am pointing out the obvious, but I have seen students burn out motors / controllers because they didn't consider this.

[Sylvestre]

They are actually brushed motors.  Thanks for the pointer.  The motor controller I am using is a Sabertooth 2x60 so it has a active cooling system and a thermal protection system.

[Full HD]

If you are still worried about overheating maybe you can use special rounded heatsinks designed for motors . You can find them in hobby shops .
Also you can try using a peltier module to cool it , if it's an inrunner that is

[Sylvestre]

If you are still worried about overheating maybe you can use special rounded heatsinks designed for motors . You can find them in hobby shops .

I couldn't find any for the size of the motor I'm using, which is a 24v 900w scooter motor.   Thats what I was trying to accomplish with the image you see above, a heatsink that encases the motor.

Also you can try using a peltier module to cool it , if it's an inrunner that is

Wow! I have never heard of peltier modules.  They look very useful.  Thanks for bringing them to my attention.

[jwatte]

Peltiers are really nice, but also use a fair bit of juice...

You could conceivably machine or cast appropriate-size round heat sinks yourself, using thermal compound to fill in the slight gaps, but that seems like a lot of work :-) If you can enclose the motor and move a bunch of air over the extent of it, that will probably work well (as long as you don't overtorque the motor way too much!)