Help with a Delaval 75

[jnarmstrong]

Good Evening!
I was just given a Delaval 75 with a working motor. He said it wasn't getting any vacuum so I took one of the face plates off and I noticed a couple of problems. First off, when I turned the pulley by hand, the drum would not turn with it. The shaft just turned inside the drum. I don't know much about these pumps, but I couldn't find a set screw or a keyway or anything to keep those turning together. Secondly, and I think more of a problem, is that the housing on the pump is pretty well banged up. I noticed somebody mentioned using a cylinder honing tool, but I think I would have to take out a fair amount. I am not sure how much you can take off. The gouge looks to be between a 1/16 and 1/8 of an inch. Is this too much to try to fix? I would appreciate any input. Thank you very much!

[Bricklayer]

You have a spin shaft. I use Delaval 73 pumps and it’s common. There is no set screw between the drum and shaft. It’s pressed on.
I’ve never seen a 75 but I assume it’s similar to the 73.
What I have done to mine is
remove shaft and clean. Remember what way it goes in because it’s important. The shaft is hollow and should have a couple holes in it that line up with holes in the drum. This is where the oil flows through to lubricate the drum and vanes.
I have a heavy gauge wire that is exactly the same size as the holes in the shaft and drum that I use to line up the shaft and drum. Put a wire in each hole to make sure they all line up and hold everything together exactly where it should be.
Take to machine shop and get them to weld shaft onto drum. The drum is cast. So you will have some pushback but it is possible. Just have to be careful not to give it too much heat or it will warp the shaft and drum won’t turn in housing.
Option 2.
Drill a set screw into drum. I did this on one of the pumps and ended up putting 2 set screws in. One at each end of the drum. Also put a little notch in the shaft to get a good hold. Can not go too big or it will impede on the oil. Just enough to hold it right on the shaft.
Just make sure all oil holes in the shaft line up perfectly before you install set screw.
Honing the inside of pump housing works well and is never a bad idea. As long as it’s done properly

[jnarmstrong]

Great input! Thanks so much!
In order to hone this properly, it has to be done all the way until it is perfectly cylindrical, correct? No gouges or scoring.
Thanks again!

[maple flats]

If you leave even a small scratch, it will work, but will shorten the lifespan of the vanes. When you say the gouges are up to 1/8", is that the width or the depth? If depth, check how much extra thickness is available on the housing. It likely has enough, unless maybe the bore has been honed too much already. Unless you are experienced doing this, I suggest you take it to a machinist and get it turned on a lathe. Those gouges sound like a little too much to just use a hone.
Where in the Adirondacks are you? My brother does machine work and has a lathe that can do up to 12" outside diameter I think. He is in Canastota. PM me if you want his contact info. If he can't do it, I have a buddy who rebuilt my front idlers on my excavator. He turned them, (about 13") O.D. I can also get his info if you need it. Back when I needed it my brother didn't have a lathe big enough. He now has the huge lathe and a big vertical milling machine.

[jnarmstrong]

It looks like something was out of round in there for a while and there is a part of the housing that has a longer diameter than the rest. It is in pretty bad shape. I am not explaining it very well. I will try to upload a picture of it.
Thanks a lot of your offer for your brother's help, but that is about 2 and a half hours away. We do have a local guy with a machine shop that I will try first. If that is a strike out, I may try to contact you. I do think there is enough housing to get the problems out of it and still have enough "meet" left.
All good input and much appreciated!

[maple flats]

OK, if it measures out of round I think machining is a better option. Hopefully the local machine shop can handle it. Also, check Hamby Dairy Supply, they might have vanes if you need them. If not just do a google search, you should be able to find new vanes if needed. The vanes should be free moving in and out and the surface towards the housing being machined should be free of nicks and pieces missing. When a vane pump runs, centrifugal force pushes the vanes out to make a seal and the air being moved is pushed out the out port. The system having vacuum put to it, ties to the pump inlet.