Non-magnetic Retaining Rings removal from 2 pole generator rotor

[edison123]

Looking to any of the eng-tips pros who have the experience of removing the rotor retaining rings from 2 pole generators (scottyuk, epete....)

What is the temperature for removal of the retaining rings from the rotor ?

What is the temperature for fixing of the retaining rings ?

Muthu

http://www.edison.co.in

 

[byrdj]

I've only watched, but the notes I have;
Do not exceed 325C,
if 18-5, do not exceed 300C
doing so damages the heat treatment

at 90C delta, apply jacks and contine heating till free, maximum 288C expected

reassembly 288C with differitial less than 50C
wait 10 minutes, the mic to verify
then go for it

 

[rmw]

If you are going to ask Scotty, you are going to have to refer to them as "end caps".

BTW, how do you plan to heat the end caps/retaining rings.

I have worked for companies that thought that the only way was induction heating and for companies that thought that the only way it could be done was with flame. Neither would be confused by the fact that others did it the other way.

rmw

 

[waross]

Hello Muthu. It's nice to see you again. It's been awhile since we have heard from you. Welcome back.
Yours
Bill

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[edison123]

byrdj - Thanks so much. That's close to what I have been doing for many years now. 230-250 deg C for removal and 280-290 deg C for fitting. But I am now stuck with a rotor where even heating up to 300 deg C didn't release the sucker. Wondering what I am doing wrong. Checked for all locks. None present.

rmw - I have been always the induction heating kinda guy. Clean elegant heating. . Flame heating of RR ? Gahhh. What other way is there is do it ? Or is it a trade secret ?

Bill - Thank you so much. Growing business. Travelling everywhere. Yeah, I know. Weak sauce.



Muthu

http://www.edison.co.in

 

[byrdj]

again, just what I've seen/read. when you say checked for locks, does that enclude the type where you have to rotating the ring.

 

[ScottyUK]

rmw,

After a few years on here I am becoming bi-lingual.

On this question I'll defer to the mechanical trades. Sorry Edison.

 

[Addy71]

There is no way that the rotor retaining rings don't have locks, just need to find them. Some have external nuts; other have circlips. Some have both. Often; the circlip won't release till you cross 200 C. I've always used gas torches, work just fine. Induction heating equipment is a lot more expensive! I assume you are using jacks too; I once had to use two 50 ton jacks + pulling studs to get the ring off. What make & MW rating is this machine, by the way?

Regards,

Aditya

 

[edison123]

Finally removed both the rings. Turned out my heat rate was too high. Dialed it down and got them out rather easily.

Addy171 - No locks/nuts/circlips were found. It's a 30 year old Brush machine that was never overhauled. You can imagine the end winding condition.

Thanks for your tips, gentlemen. Much appreciated.

Muthu

http://www.edison.co.in

 

[byrdj]

Thanks for letting know the results
I guess I should have added this note I read in the GEK
"— heating time 1/2 hour to 1 hour"

 

[rmw]

See,

It was a Brush rotor and it knew that it should have been heated with flame heat and not induction heating (or so the Brush lads would tell you.)

I got back to this thread too late to tell you that I thought you might be heating the rotor teeth as well as the end caps with the induction method.

Which machine is it? And, if it is that old, it is probably 18-5 metallurgy. Are you going back with 18-18? If you are getting them from Brush, you better start planning a bank robbery somewhere.

I do have a good mental picture of what the end windings look like. Good luck.

rmw