Anybody know vacuum pumps?

whipped · Post by **whipped** » Thu Aug 17, 2006 9:45 pm

I have an Ulvac 2(?) stage rotary vacuum pump. You run the thing for more than 10 minutes, and somehow oil works it's way into the vanes, and it hydrolocks. Disassembly to drain it fixes it... Any ideas? I don't know how this thing works, but it goes have an oil pump. I'm guessing it's pumping too much or it's sucking in oil somewhere else?

It would come in handy for an A/C evacuation... or fiberglassing... just need it to work dammit!

Post by **eHoward** » Thu Aug 17, 2006 10:02 pm

I think you just put it on there and squeeze the bulb

http://www.babeland.com/penis-pump.html

whipped · Post by **whipped** » Thu Aug 17, 2006 10:15 pm

If it had one of those attachments, it would probably tear it off or turn me inside out.

rube · Post by **rube** » Thu Aug 17, 2006 10:18 pm

Must be a seal. Didn't see any support info on their website but here's an MSDS sheet in case you swallow it:
http://www.ulvac.com/msdssheets/R2.PDF# ... vac%202%22

Post by **eHoward** » Thu Aug 17, 2006 10:19 pm

Do you have $150 to spend on a pump that is designed for vacuum bagging?

whipped · Post by **whipped** » Thu Aug 17, 2006 10:20 pm

It looka-lika dis:

Ulvac GVD-050A
60 L/min
6.7*10^-2 Pa

I've read on the net that the gas valve on top there might have to be open or closed when you power it on, then shut it? Or you're supposed to follow some procedure?

whipped · Post by **whipped** » Thu Aug 17, 2006 10:22 pm

eHoward wrote:Do you have $150 to spend on a pump that is designed for vacuum bagging?

Between my dash, AC install, and quarter panel fiberglassing woes.... no.

I figure if I can get it to run for 30 minutes straight vs 10 minutes, I'll be golden for just about anything.

whipped · Post by **whipped** » Thu Aug 17, 2006 10:24 pm

rube wrote:
Must be a seal.

That's the wierd part... it has no seals. The pump is made of like 2" Dia x 1/2" thick blocks stacked on each other (total of maybe 10 blocks). It makes up the vane housings and the oil pump. They're just bolted together, metal on metal.

txf · Post by **txf** » Thu Aug 17, 2006 10:48 pm

Sounds like there's too much or too thick oil in it. I've used many and the only time I've seen one lock up it was either spinning the pump the wrong direction or had too much oil in it.

whipped · Post by **whipped** » Thu Aug 17, 2006 10:50 pm

hmm... I just filled it between the red lines (you can see on the clear plastic thing above)... I assumed those were min/max lines, but I don't have a manual...

whipped · Post by **whipped** » Fri Aug 18, 2006 7:18 pm

Would pictures help at all? :thumbleft:

whipped · Post by **whipped** » Fri Aug 18, 2006 7:48 pm

Teh outside:

Inside, the pump assembly:

Other side, showing the gas ballast valve, and tubing full of oil ( :scratch: )

As I understand it, the valve is used as a bypass(?) for the first stage? So I guess if you open the valve, the compressed air from the first rotary stage will just get exhausted out the valve instead of moving to the next stage.

Shot of the oil pickup screen on the bottom:

Any thoughts yet? The oil in the ballast line probably indicates the problem is with the first stage?

p8ntman442 · Post by **p8ntman442** » Fri Aug 18, 2006 8:55 pm

too much oil, or wrong viscosity. I say tap the housing and put on a petcock, then drain it as needed. Thats the fiero owners fix.

rube · Post by **rube** » Fri Aug 18, 2006 11:26 pm

Leak at the air line fitting? What is the oil for? It appears that the actual pump assembly is surrounded by oil. It looks like there are plenty of places for oil to leak in. Take apart the stack and give the mating surfaces a very thin layer of locktite blue.

whipped · Post by **whipped** » Fri Aug 18, 2006 11:50 pm

Correct

the air line is under pressure so if it were leaking it wouldn't do anything.

The oil is for lubrication and cooling. I'll post more pics tomorrow, my batteries died

whipped · Post by **whipped** » Sat Aug 19, 2006 2:29 pm

More pics...

The oil pump:

Behind that block:

Removed that block:

As soon as I pulled that off, the thing was able to turn smoothly. Thoughts? Need any pics of something specific?

(Click reload if the pics don't load, the server seems to be slow/intermittant today)

whipped · Post by **whipped** » Sat Aug 19, 2006 2:48 pm

I wonder if the seal behind this bearing is leaking:

You can see the oil feed groove, and presumably the oil is under pressure...