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Splitting the Crosshead, k582 Separation of Piston Rod
https://www.rypn.org/forums/viewtopic.php?f=1&t=39033		 Page 1 of 2
Author:  softwerkslex [ Sun Jan 24, 2016 11:17 am ]
Post subject:  Splitting the Crosshead, k582 Separation of Piston Rod
We are trying to separate the piston rod and crosshead, and not having a good time. This is a tapered rod secured by a tapered key or wedge. We tried a three piece assembly that looked like it had been used in the past. It has two pieces and a wedge designed so that hammering the wedge forces the rod out of the crosshead. It fits into the taper wedge slot in the crosshead.

Well, we hammered this thing solid with a sledge hammer, and the rod did not budge. And it is jammed in tight now. Trying to hammer out the wedge from the other side just bent it and peened over the end. Part of the problem is we can not get a straight blow at the wedge from below because the truck interferes.

I have seen some pictures that show the crosshead being heated with torches for this operation. Does everyone do this?

I have seen pictures of a tool that forces the rod out with a threaded screw from the bearing side. This requires removing the main rod.

Pictures of your tools and methods would be appreciated.
Author:  G. W. Laepple [ Sun Jan 24, 2016 11:38 am ]
Post subject:  Re: Splitting the Crosshead, k582 Separation of Piston Rod
Assuming you have the key out, take a torch and warm the crosshead, not hot, just warm to the touch, and then try your wedge thingy again. It should pop the piston rod right out. My father-in-law, a PRR steam machinist, told me this trick some years ago, and i've used it successfully several times.
Author:  Rick Rowlands [ Sun Jan 24, 2016 11:57 am ]
Post subject:  Re: Splitting the Crosshead, k582 Separation of Piston Rod
When I split the crossheads on J&L 58, I heated the crosshead casting up considerably before even trying to force them apart. I don't see them coming apart without heat.
Author:  10stewi [ Sun Jan 24, 2016 1:44 pm ]
Post subject:  Re: Splitting the Crosshead, k582 Separation of Piston Rod
Well that helps with deciding what to do next time! Now with that answered, what is the best way to get it all back together so it is nice and snug?
Author:  Dave [ Sun Jan 24, 2016 2:44 pm ]
Post subject:  Re: Splitting the Crosshead, k582 Separation of Piston Rod
The tapered key should draw it up tight when it is driven into place.
Author:  Kelly Anderson [ Sun Jan 24, 2016 3:40 pm ]
Post subject:  Re: Splitting the Crosshead, k582 Separation of Piston Rod
.
Author:  jasonsobczynski [ Sun Jan 24, 2016 4:12 pm ]
Post subject:  Re: Splitting the Crosshead, k582 Separation of Piston Rod
I used to do that also, until I read through the part of the "Advisory Mechanical Committee" (AMC consisted of the CMO's of the Erie, NKP, C&O, and Pere Marquette) expressly states that no lubricant of any type should be utilized in these sorts of fits including those of wrist and knuckle pins.
I was intrigued by this and consulted with G.Mark Ray, he explained why this is a must (or must not I suppose) from an engineering standpoint. I honestly don't remember the specifics but perhaps he may chime in.

And absolutely yes, heat helps! At all cost, avoid hitting the side, front or any part of the crosshead with a hammer of any type. Doing so may well be effective in getting the rod out but it accomplishes this by moving metal and effectively enlarging your piston rod fit. This then results in your piston rod fit A) being out of round and B) means your rod will seat further into the crosshead changing the position of your piston in the piston bore.

Cheers, Jason
Author:  Dave [ Sun Jan 24, 2016 7:17 pm ]
Post subject:  Re: Splitting the Crosshead, k582 Separation of Piston Rod
I've also had good experience applying pressure on the stub of the piston rod with a hydraulic jack through the crosshead or against the crosshead on both above and below the piston rod then applying heat to the entire area of the crosshead with a torch gradually until it simply pops loose. This makes for a good one man job of it.
Author:  Frisco1522 [ Sun Jan 24, 2016 7:21 pm ]
Post subject:  Re: Splitting the Crosshead, k582 Separation of Piston Rod
I always found that when using a big hammer, it always helped to invoke a curse on the final blow. Worked every time.
My favorite was "MOTHER IN LAW". Make sure you are a good shot with the hammer.
Author:  dinwitty [ Mon Jan 25, 2016 9:19 am ]
Post subject:  Re: Splitting the Crosshead, k582 Separation of Piston Rod
Reminds me of the tender pin on 765, it would not come out, air hammering broke the bit, WD40 tried...it took a power hydraulic ram lifting to do it. Heating could not work, just tooo big.

I'm reminded of the film Last Of The Giants about the big boy, they used a ring around the driver lit up to heat the tread to remove it. Perhaps propane so not to bring it to weld heat. You don't want red hot or you might work out the steel hardness.

You could fashion some piping shaping it around the crosshead with holes drilled aimed at it hooked to the propane, light it up. The heat may nudge the parts around freeing things a bit.

old lube may only cake and inhibit your purpose, heating might mini-explode making pits.

I wouild not slam it anymore with a hammer, might deform parts. An air tool ram of some sort sounds key to me. or an auto jack (them spin turn things or pump hydraulic design)

throwing ideas out to try.
Author:  softwerkslex [ Mon Jan 25, 2016 9:26 am ]
Post subject:  Re: Splitting the Crosshead, k582 Separation of Piston Rod
Thanks all
Next work day is Saturday
Author:  Bobk [ Mon Jan 25, 2016 12:10 pm ]
Post subject:  Re: Splitting the Crosshead, k582 Separation of Piston Rod
We had that same problem and no matter what we did could not get the tapered end out of the crosshead. We finally made a new wrist pin with a flat on one side. Inserted into the crosshead the flat was towards the taper. Between the tapered end and flat we placed a porta power hydraulic piston and pumped it up to many tons. Nothing happened however we left it to sit under pressure. It took a few days and one day we heard the porta power fall out. The rod moved a few thousands letting the porta power slide out. Then the other side was done the same way.
Author:  RaA [ Mon Jan 25, 2016 5:03 pm ]
Post subject:  Re: Splitting the Crosshead, k582 Separation of Piston Rod
I think Your K 582 have a similar design like our norwegian crosshead/piston rod. Wedge system installed and tight - then wrap an old rag wet/(or snow in between) round the rod close to the krosshead. Then heat fast and furios ( large acy/oxy) and the parts will split with a loud bang. Some hammerblows to the wedge at the same time can help, need more arms.
We dont have the wedge system. Crosshead pin with large acmetreads. Thighten up the screw, Three blows with the five kgshammer an tightening at the same time. Then same heat procedure and five kgshammer. (10 pound hammer for those not so metric :-))

Regards
Ragnar Andenæs, NJK/UHB.
Author:  thunda [ Tue Jan 26, 2016 1:59 am ]
Post subject:  Re: Splitting the Crosshead, k582 Separation of Piston Rod
Had the same issue on a loco here in Australia where we were splitting the rods/crossheads for the first time since it's last running repair in the 1960's.

We had a threaded tool for applying pressure to the end of the rod but even with 6 people hanging off a 15' bar on the end of a 1" ratchet it still wouldn't budge.

So out came the oxy set and we heated one side of the crosshead where it rod sits into it (just a long thin strip) to cherry red. Tried again on the ratchet and it moved with just 1 person pulling..... Same method was required for the other side. The localised heat was enough to release some of the tension on the rod taper, without having to heat the entire crosshead/get to much heat transferred into the rod.
Author:  John Ezovski [ Wed Jan 27, 2016 3:49 pm ]
Post subject:  Re: Splitting the Crosshead, k582 Separation of Piston Rod
The CTRC group experienced the same problem separating X-SP-2479's cross heads from its piston rods. We tried many of the processes described in earlier posts with no success. One of our concerns was inducing to much heat into the cross head.

Our mechanical adviser remembered seeing an example of a cross head grease press. Images of the press are included. We were careful to ensure that the press would fit both cross heads as they were not the same.

Our first attempt with a light grease failed as it was excreted between the piston and its walls. We switched to material used as journal grease for the main drivers. This worked really well. There was a very loud report when sufficient pressure was applied.

I've included several photos of what the press looks like.

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