Is it better to mount cooling fan on comm. end or opposite comm. end?
It seems that if the fan is mounted on the comm. end, carbon from brushes, would travel through motor and possibly cause tracking to ground. Have seen fans mounted on either end , is there standard rule of thumb?

Also want to add a tip. 3 years ago we added fresh air ducts to bring in outside air to all our DC motors and our brush life has increased 300% and motors run cooler plus air exiting motors is cooler. Money savings has been huge!!! Bean

Bean440:

Yes, that should be expected. Heat is the enemy of all dielectrics (including carbon brushes). You will probably note that bearing life is extended and torque response is better because the field resistance is a little lower (more current) by just a bit.

If the air is properly filtered, then you should not have a problem. Internal fans and the way banding is placed on the commutator are used to move air around internally. These cause carbon to collect in interesting areas. My experience is that the incoming air tends to keep the carbon away from the windings and commutator due to the air velocity and, if the air is given a direction to escape...

I generally found that bringing the air through the commutator keeps the commutator cooler - which tends to be one of the hotter spots within a DC machine - and clean. Also keeps the carbon dust away from the brush rigging.

Sincerely,
Howard

Hi Bean..

It has been a long time before you posted this, but now only i got the chance to read it!!

By the way i'm interested to know more about the way you people could add fresh air ducts into your motors!!We have lots of DC motors here and heat is a real problem...We have the cooling fans installed on the commutator end,but sometimes it will blow the carbon dust into the windings and some times the cooling is not sufficient!!

If you have any drawings or pictures about the modification done on the motors,it would be better for us to try the same!!

Or else we are planning to have heat exchangers instead of these blowers..Will it helps or not?

Thanks in advance!!

Have a nice day!!

quote:

ducts

Sometimes when It´s hot water air cooler is the best way to cool Dc motors that my experiance
BR