How to ensure bundle installed without drag on oring overlay area ?

[rQuestionEngineering]

Referring to the centrifugal compressor attached.
How to ensure bundle installed without metal to metal dragging on oring overlay area ?
Diametric clearance is about 0.2 to 0.5 mm when fully seated.

 

[GregLocock]

lasers, levels, cameras. You need a laser on each end of the core at the shackle, and a target on a wall somewhere.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[3DDave]

a) Drop in vertically?

b) Put the housing on rails and hold the rotor still? That way the housing can be moved to position, inspected with laser theodolites, and then moved along the rail to intermediate positions, confirmed with laser theodolites. Then introduce the rotor and confirm that none of it will interfere with the positions verified for the movement of the housing.

Go for the bonus and apply heaters to the housing to get a bit more room, but do the inspection at the raised temperature.

 

[desertfox]

Hi bayan1999
If you can't drop it vertically, is it possible to provide a central guide rod from the opposite end of the compressor casing for the bundle to pushed onto.



“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[JJPellin]

We have many barrel pumps and compressors. None of them have one straight bore as your drawing suggests. They have a series of machined steps. Each o-ring has an associated bore with a close clearance that engages an inch or so before the o-ring reaches its bore. These other pilot fits lift the bundle up close to center so there is little or no drag on the o-ring sealing bores. When I get back to work I can post a drawing.

Johnny Pellin

 

[JJPellin]

The larger bundles on machines like this have built in rollers that hold the bundle up off the bottom of the casing and reduce the drag during insertion. Close clearance fits pick the rollers up off the bottom of the case once fully inserted so that they do not leave indentations in the bottom of the casing.

Johnny Pellin

 

[Compositepro]

Is "drag on the o-rings" even an issue? The o-rings are in a groove that limits how much they can be compressed. The weight of the compressor bundle is never supported by the o-rings.

 

[rQuestionEngineering]

@ Johnny Pellin
The roller can roll over the oring overlay area, but after it passed, the heavy bundle is not supported anymore.

 

[JJPellin]

That would be a very strange design. I made this sketch when I was adjusting a set of rollers in 2012. This also shows a representation of how the o-ring sealing surface at the nose of this bundle is protected. Use lots of grease and you will not have a problem. I have done dozens of these insertions and have never had an issue.

Johnny Pellin

 

[JJPellin]

There are usually certain bores along the length of the casing where the weight of the bundle is supported. These areas are generally not where an o-ring seals. In our bundle. The area marked in RED is the main support for the nose of this bundle. There is another area at the opposite end. And, in many of these machines, the head has a fit that lifts the back end of the bundle up to center as the head is installed.

Johnny Pellin