surface treatmetn for stator

[leslie2000]

We are facing a problem about the anti-corrosion of stator:
We use silicon steel and punch it to the shape we need. And then we will weld them together to form a stator about OD200mmx180mm Length.

Because there are many deep grooves on ID, we tried several coatings to protect the stator: Zn coating and black oxidation; but the results of both are bad. There are corrosion on ID and grooves. The reason is 1. For Zn coating, it could not be plated on the groove,2. For black oxidation, because we need to remove the oil before assembly, so it is corroded quickly in application.

We considered to paryline coating, but at present there seems no factory who can work on such large part.

We are wondering if someone can help us with this? We want to find a way or coating to protect the stator. Thank you in advance.

 

[UKpete]

A wound stator is normally dipped or impregnated with a resin such as an oven-curing epoxy, and this suffices to protect the stator laminations.

It is also common to apply a polymer coating, usually referred to as an anti-tracking varnish (because of its resistance to electrical tracking across its surface), to both the end windings and the exposed surfaces of the laminations. I am in the UK and the one I have come across is from U372 from AEV (

http://www.aev.co.uk),

which I think is available in both brush on and aerosol spray form. But similar products should be available from any supplier to the electric motor manufacturing or repair trade.

 

[electricpete]

Threre is an interlaminar insulating coating on the individual laminations before assembly, isn't there? You didn't mention it. I think that should help prevent corrosion.

The deep grooves you mention would be the stator slots I assume. So apparently the corrosion you are talking about occurred after core assembly but before the stator was wound?

I agree with Scotty, the stator vpi resin should do the trick once the stator is wound and vpi'd. I wouldn't think there is need to manufacture cores long before they are wound.

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[ScottyUK]

ePete,

It's your UK-based namesake you should be agreeing with!



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

 

[electricpete]

Whoopsie. Guess I must have been confused by the fact that you guys both have uk in your name. Doesn't take much (to confuse me, that is)


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[UKpete]

Pete, I'll let you off - it was after all my first post for about three years. I've been away you see.

 

[electricpete]

Thanks. And by the way...
Welcome back!


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[sreid]

I would think that a silicone conformal coating from Humiseal would work.

http://www.humiseal.com/

 

[leslie2000]

Thanks all for your help. Sorry for my bad English. Electricpete, your assumption is correct that "the corrosion you are talking about occurred after core assembly but before the stator was wound?
", because we will ship the core assembly to our customer who will wind it at their end. And the shipment will take about 40-50 days. So when they receive it, the slot began corrosion.

So we want to find a way to protect stator (before winding) during the shipment. Can you suggest how to do?

Thank you!

 

[sreid]

Could one wrap the stators in corrosion inhibiting paper for shipment?

 

[UKpete]

You could also try something like Castrol Rustilo DWX30 (or similar), which is a very thin brush-on rust prevention fluid that I have seen used, this would get into the slots. I believe there are also spray-on rust preventers, although I have no experience of them.