Delaval 73 spun shaft

[Bricklayer]

Lost all vacuum yesterday. Took pump apart this morning and the pulley turns but the drum with the vanes dosnt. I'm assuming the shafts are pressed in.
Anybody know of a way to fix this.

[Brian]

Is the key way twisted off between the pulley and shaft? Or is the shaft twisted off next to the drum? Check those things. Good luck.

[Bricklayer]

They only keyway is the one on the shaft to connect the pully. It's fine. The shaft turns in the drum. It takes some effort but it will turn. No play back and forth so that's good.
Wonder if I can get it welded?

[Haynes Forest Products]

I know this doesn't solve the problem but when I was contemplating a dairy pump set up CDL was redoing DeLaval pumps. The internal shaft was strengthened to take the strain of hard starts having heaver oil and more of it. I would look there first.

[Bricklayer]

I think what caused it is when the pump runs out of gas. It just stops basically dead. I have a check valve on the vac line so it won't cause the pump to spin backwards but the pump still stops pretty quick.
When I shut pump off I open valve on vac line until vac is 0 then I shut pump off. Same thing when I start it. I open valve and wait until motor is running then slowly close the valve over a 5 minute span.
This happening maybe 30 times this season is probley the culprit. I think a couple good set screws into the shaft will do the trick. But if they ever come loose and start chinging around in pump that will be the end of the pump for sure.
What I did notice on the drum is there is holes drilled in the drum behind the vane slots. 2 holes in each slot. I can see the shaft through these holes. What I don't know is if these holes are supposed to line up with holes in shaft. The holes aren't threaded for a set screw. But are they meant for oil to run through?

[BreezyHill]

The 73 and 75 are pressed shafts with a common rail oiling system. If you cant get the drum to the correct and precise location of drum to shaft aliment then just redrill the hole behind the # 1 vein.

Failing to do this will destroy the pump in less than 1/10 way thru the next run.

Use a single led light to shine down the common rail and rotate the drum til you see light.

Spot weld ezch section of the drum to the shaft so as to not warp the shaft.

Good Luck!

[Bricklayer]

I am able to line the holes up. I'm assuming I can use the holes as a guide to make sure it's aligned and shaft isn't in drum to far before I get it welded ? Should drum be pre heated before it's welded since its cast?

[Brian]

If the holes line up,could you use roll pins to hold it in place? They are hollow so oil could go through.

[BreezyHill]

I have welded several and never preheated them. I use a mig, straight polarity, high temp setting of 4 of 7 and around 55 on the spoil feeder speed.

If the hole is plugged the unit will not suck oil thru the common rail oil system and the bushing will run dry and be toasted in a couple minutes, then the drum hits the housing and the pump is junk.

A simple NO is not the best teaching method. An explanation of why not; is more enlightening.

[Bricklayer]

Should the bearing be pulled off to weld that side or just weld the end without the bearing.
Getting it welded hopefully tomorrow morning.

[BreezyHill]

I only weld one side so that in the future it will be easier to remove the shaft for a new one.

[Bricklayer]

It's in the welders hands now. Dropped it off this morning. So fingers crossed he will be able to make it like new. I was able to line up the oil holes and put some screw drivers right through holes to hold it. They were exact size as holes so it worked out great. He's going to TIG weld it. He said he would be more comfortable doing it TIG to control heat. I didn't argue. So I'll have it back together tonight and running so I'll post how it turned out.
By adding the welds will it throw the balance of the drum off a bit? Hopefully not. But thought I'd ask.

[Wanabe1972]

Tig welding will add little to no weight and being in the center of that big drum I highly doubt you'll notice it. I have access to a full machine shop so when I spun the shaft out of my 74 I made a new shaft with a flange on one side i taper pinned to the drum. The tig weld should be a fine fix. Jeff

[Bricklayer]

Just put pump back together with welded shaft. He welded it on both sides and checked it for balance.
He told me if it spins loose again they can knurl the shaft and re press it in drum.
I i wouldn't even know how you'd line up those super small oil rail holes while pressing it in.
But at least it's an option.
Pump is running now so all seems good.
Fingers crossed.

[BreezyHill]

If repressing, just redrill the shaft where it is aligned at. The old hole will be plugged off by the drum.