DC Motor _ Needed

[lukin1977]

Dear Sirs

I am writing from outside US and I am asking to you if anyone knows where can I buy a DC Motor - 60 HP (see picture) in the US. Used or new. Best if is near to Miami

Any link?

Thanks

lukin1977

 

[rasevskii]

Try Belyea Equipment, they have used motors and other electrical items. Google them. I think they are in Pennsylvania.

what happened? did you burn it. what are the specs, what is the driven machine...Maybe you only need to change the brushes and clean up the commutator.

Otherwise go to the OEM. It looks like a European design, was it Siemens, ABB...see their service departments if so.

regards, rasevskii

 

[lukin1977]

We have some major wear between the commutator and the brushes. We found that 2 brushe´s holders broke and the brushes were not in good contact with the commutator so it generates a lot of heat and sparks (see pictures attached)

The armature coils are fine

This commutator was already rectified several times. So I dont know if we can rectify it one more time. Hopefuly we
could

Rectify is when we put the rotor on a lathe and ground it to a cylindrical shape

Another asociated problem is that recently we replaced some normal weared brushes awith brushes that we bought localy (poor quality for sure) because here we do not have any good supplier of DC motor´s brushes. By the way, I need a good brushes supplier too

Like I said, we will probably fix this problem but we want to have a spare motor just in case because I dont see much more life for this one

Spec are:

P: 56,6 kW
U: 440 V
I: 142 A

Field
Ue: 190 V
Ie: 4 A

Tachometer:

2 volt/krpm

 

[TurbineGen]

Ouch! looks like softer brushes were in order. When you replace brushes, it is best to replace ALL of the brushes at the same time. Ask me how I learned this with my 200 MW generator exciter

It looks like you might be able to true the comm back out, but that's going to be the last time you can do it.

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If it is broken, fix it. If it isn't broken, I'll soon fix that.

 

[ScottyUK]

When you reground the commutator did you undercut the mica insulation between segments? From my limited understanding it's a task which requires a fair degree of skill to accomplish successfully, although it's something I have only ever watched and never tried. Failing to undercut will lead to brush wear and sparking at the commutator because the contact pressure between the copper and the brush is reduced as the brush rides on the mica.


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If we learn from our mistakes I'm getting a great education!

 

[lukin1977]

TurbineGen: Yes, we need softer brushes next time and yes we will replace the whole set from now on.

ScottyUK: Yes, we always undercut the hard mica. It is a slow work but it is a "must do"

I just found the Original Manufacturer of our motor and ask them to quote an Armature rotor, brushes and spring holders for stock. Maybe with buy this spare parts and one more DC motor. Depending on the cost

This is the OM :

http://www.magnetic.it

 

[rasevskii]

lukin1977:

Is there any possibility of dirt or abrasive materials entering the motor via the forced air cooling fan? In other words is this a machine shop environment where cutting and grinding are going on nearby? Or sand or other pollutants.

Just some possible reasons as well as what the others have said.

rasevskii

 

[ozsalty]

Looks like you have "slung" alot of solder as well...

 

[lukin1977]

Rasevskii

The DC motor has an independent fan with an air filter that blows fresh air into the DC motor. We change this filter very often. So I dont think dirt caused the problem. In fact we deassembly the motor and look very clean

Ozsalty. I dont undertand what "slung" means

Thanks