How Do You Free a Friction Welded Shaft Coupling?

Apply heat and a big hammer to the outer part.

Big fan of big hammers...unfortunately about zero room to fit even a small one.

Given the "small" gap have you considered wedges (large cold chisels may work for you) and heat.

1. Set the wedges (shim if necessary) load bearing on the pump and motor housings as close to the pump as possible.

2. heat sleeve

3. drive in wedges with an engineers mall (2#) using alternating blows

4. reheat or reset (with shims as necessary) wedges

Another possibility: make longitudinal cuts into the sleeve that stop just short of impinging on the shaft. Spread apart with a chisel or pry bar.

Maybe I should have explained the situation a little better. The gap between the motor and the pump is small - very small.

Who was it who said, "A negative person is one who finds a problem for every solution."?

Any chance you could post a photo? You may get better suggestions if we can see the thing!

what diameter is the shaft? coupling?

Could you get in with a dremel?

I don't know what you have available by way of a lathe, or if you have the skills, but if you or a friend could mount the whole thing on a lathe bed (securely), Use the motor of the pump assy to turn the shaft & the tool post of the lathe to turn down the collar in till there is nothing left of it, it would mean bridging the tool post mechanism to allow it to move along the length of the collar.

Bazzer

Pack the shaft in ice and heat the sleeve with a torch.

It's WELDED! Something I've done in the past is to hacksaw around the sleeve forming a spiral cut if that is possible, you have to have the room to be able to angle the saw but if the sleeve is close to the motor or pump then it can't be done that way, so back to using a lathe.

Bazzer

He has a new pump and motor - problem has been solved.

A replacement is on its way, order sent, but it's Chinese New Year over here and no bugger works (or so it seems)

Would that be before or after I strangle him?

Normally I tend to agree with solar eagle, but in this instance, " they " , who muffed up the thing in the first place, just might muck up any tools you let them use to unmuck the shaft.

I was going to suggest using a Milwaukee Sawzall . There are a variety of blades available, especially long skinny ones.

Or you take a carbide drill bit and drill into the sleeve, just don't drill all the way through it. Then use a electric solder iron ( the big ones used to solder sheet metal ) or a Bernz o Matic ( Lynn has one you could borrow ) . Get it good and hot, squirt some penetrant into the hole and yank them suckers apart.

(usual disclaimer)

If you have room for a split sleeve or muff coupling, you might install one and use some type of pry bar between this and the sleeve to break the shaft loose.

Grind a slot along the length of the tube, use a pair of pry bars to force the tube apart enough to remove the shaft, if it doesn't grind another slot on the opposite side & repeat with the bars, Before you try any of the above is there any way to,( Using the motor ) to reduce the diameter of the tube, maybe by running the motor and using a hand held grinding stone to take off the material. It's worth noting that they use spin welding to join big pipes in the oil industry & it is very strong, what you've done by accident is to spin weld the shaft to the sleeve so don't do anything unless you look at all the options or you could be looking at a new unit.

Bazzer

Perhaps you could spray one side of the coupling with something like Freon then use a drift punch and hammer to shatter it.

If the shaft has galled/seized/welded to the coupling, material will necessarily need yo be separated, cut or otherwise divided. No way around that.

After that, the shaft will need to be machined/repaired. So why avoid metal cutting processes, those will be required eventually.

you could take a cutting torch and heat the coupling red then wash the coupling off with the oxygen at a low psi (10 lbs). biggest tip as possible. the idea is to wash it off . no velocity to cut through. put a wet rag around he pump shaft at seal and the motor shaft near seals.

The assembly is now welded together. There is no option but cutting and one or both halves of the pump/motor is going to need a replacement part. For short term, put a drip pan with drain under it to milk out the pump as long as justifiable. Long term, replace one or both. Although hard to cost justify, modify operating procedures to require immediate investigation and repair next time a performance blip is noted. Modify maintenance procedures to add registration marks to shafts and couplings and visually verify them periodically.

I would assume this is a one time occurrence and it's actually not catastrophic. It's hard to justify an even mildly expensive maintenance program unless the pump and motor are really expensive, since it didn't seem to affect operations much. Is it safe to assume you are not doing acoustic bearing monitoring? This might have shown up as something really weird.

Had a manager friend who believes that managers should be allowed one hit per year. Specifically, the manager should be able to select that one special employee who is the biggest thorn on his side and take out a contract on this worthy recipient. Thus, the workplace becomes better and society is protected from the ravages of the recipient. Probably won't happen, but the thought vacation keeps my friend from developing ulcers.

I once worked with a kid named Timmy. Gangly kid fresh out of high school who couldn't walk and walk at the same time. You've seen 'em. He tried hard, but couldn't get past basic coordination issues. He went to work in shipping. He was single-handedly responsible for the removal of all nail guns from shipping as a safety measure. After stuffing the forks of a lift truck through a closed 10' wide door, he was moved to assembly and was put on an automatic packaging machine where he was to set open cartons on a conveyor and remove closed cartons from another conveyor. He left employment after accidentally strapping his head to a box at the end of the automatic packager, earning the nickname "gator" (The foreman observed the occurrence and commented, "It looks like a gator got him) and joined the army where he finally grew up and filled out. After two years he was a corporal in charge of a 50 cal machine gun crew. Folks at the factory were amazed the army had given gator a machine gun. He turned out good. Happy ending.

Yeah the were doing acoustic bearing monitoring - "..it was making a loud racket then stopped ...so never mind..."
Replacement coming and fairly cheap.

It was that it has chosen the worst fortnight of the year to die - every bugger is on CNY holiday so getting the replacement is a problem.
I could quite like your manager friend...

Why did the seal fail? Did the shaft parts over heat as they welded themselves together? Did the coupling fail because one of the bearings, either on the motor or the pump wore out and allowed the shaft to wobble? Did the heating of the shaft reduce the strength of the shaft to the point that it will fail anyway soon after a new seal is in place? Some times it's just cheaper to start with a new pump. If the replacement is not readily available, can you get a substitute? It could be an opportunity to upgrade the pump, get more performance or longer life between replacements.

As a rule "stuck together" and "welded together" have very different outcomes...

I suspect there will be no satisfactory repair. After friction welding, the shaft and seals will be damaged.

The motor shaft will need to be machined, and that means taking the motor apart.

At 1.5Hp - you replace both pump and motor. Too small to bother with.

The O P , says that the motor is a 1.5 hp unit. According to Honda parts, that could be a GX 31 or a GX 35 engine. Then again, it may be entirely different.

Both of the GX engines are horizontal shaft, as is shown in the image. Both ends of the shaft are threaded, one side is keyed and one side is not. One side is for magneto and one side is for takeoff.

According to Wikipedia, Honda has produced over five million small utility engines and the 1.5 hp engine, is , was, produced in half a dozen variations.

A replacement GX 1.5 hp motor / water pump unit is approximately $ 500.00 to $ 550.00 usd.

You bring up a good point! When I see the word "motor" (as in the OP), I normally think electric, unless there is context suggesting hydraulic- or air-powered.

If a fuel is burned, then I call it an "engine"

But the name "Honda" does suggest a fueled engine, rather than a motor.

I just discovered that Honda makes a submersible pump, that is similar to a little giant pump.

Awhile back I replaced a little giant pump in a port a cool unit. The shaft seal had failed and the reservoir basin was sorta full of oil.

That is the only other electric Honda unit I know of.

What say you ?

tomatoe - tomato

potatoe - potatoe - spud... I'm Australian in Malaysia
Yep Honda 1.5 petrol power thingy

Thanks. That changes the mental images significantly.

I have no idea why someone marked your reply OT, except that they probably hadn't read the entire thread; at least not my post that you were replying to. Here's a GA to counter that.

Someone recommended using a sawzall (reciprocating saw), and I agree. I happen to have the Milwaukee brand mentioned, and have been really happy with it, but there are others. One thing I'd add is to use a triangular file to make a starting groove. otherwise the blade will tend to walk all over the place. One or two wooden sticks could also be used to keep the blade in one spot until you get a groove started.

Since you said that the key had fallen out, the coupling is probably not centered on the gap between the two shafts. If the shaft inside the point where you cut is hardened, you may have to cut down 'till you touch the shaft, rotate the shaft a bit, cut again, etc., until you have cut the coupling in two. If cutting all the way around does not free the pump from the engine, at least you will have a place to use a couple of screwdrivers or cold chisels to pry further.

The reasons I marked that post as OT are:

1. "tomatoe/tomato" does not convey the pronunciation difference between tomayto/tomahto.

2. No one ever says "potahto" except when mistakenly characterizing "tomahto".

3. Moreover, "potatoe/potatoe" conveys no distinction whatsoever.

4. "Petrol power thingy" scarcely means anything at all.

Lets saw the whole thing off.

I think they skated around the issue.

".... Moreover, "potatoe/potatoe" conveys no distinction whatsoever. ..."

Are you sure about that? It conveys a very distinct 'Dan Qual-ish' flavor of spelling...twice, just in case you missed it the first time.

Everything might begin with an 'e' and indeed any vegetable ends with an 'e', an 'e' goes after the final 'o' in potato or tomato is cases such as plural when additional letters with then follow.

Potato Potatoes Potatoe

Tomato Tomatoes Tomatoe

This should be true even for an Aussie living in the wild Wild East, or anywhere else in the land of Malay.

Yep dead right . Just delivery because of holidays.
BTW the motor pump unit here is about 2k so pretty much the same price.

Drill a suitable hole, insert a grease nipple and pump it off with a high pressure grease gun.

That would require drilling into the shaft, in order to allow tapping, before the nipple could be placed, and one or both shafts may be hardened. There may or may not be a gap between the two shafts, but even if there is one, there is probably no way to know where that gap is located. Then, even if the two shaft lengths are known, it would be difficult to measure accurately in the small space between the engine and the pump.

Just as an observation :

The answers that appear, " silly " get a 1 score for Good Answer.

While the answers that even have a hint of good sense get an, " Off Topic " , or nothing at all.

You just provided an exception! ...but I see what you are saying...

Explosives?

Under the worker? Considered but apparently it's illegal....

New one arriving tomorrow so thanks to all.

It sounds as though this thing doesn't need to be freed off now, then. Oh, well..