Solving the Tight Fitting Annulus Problem at Work

[kieren12345]

I have a problem at work!

We have a large annulus that we need to fit a shaft into. I have calculated the tonnage required and it is outside of our workshop facilities.

Any ideas, Lub, etc?

 

[Ranger Mike]

i would not comment on this post if i had too!

 

[kieren12345]

Its a real tricky problem in my line of work. I am worried about damaging the shaft.

 

[dr dodge]

could the shaft be cooled with LN2 and the outer piece be heated? If you know what the interference fit of the 2 would be, simple expansion contraction formula would tell if its doable

dr

 

[FredGarvin]

Heat the outer and chill the inner. That is about all you can do. Like was mentioned, use the materials to find out the CTE of each component and find out the delta T required to give you the clearance required for assembly.

 

[hhn2002]

i guess this is one of those questions you have to be really careful in how you word it.

 

[turbo]

Some of the equipment on the paper-machine had interference-fit sleeves on shafts, and the millwrights fit them by putting the sleeve/collar/etc in a large portable induction heater until it had swelled sufficiently, then quickly pressing it on the shaft. I don't recall them ever cooling the shafts, but the sleeves were plenty hot when they went on.

 

[kieren12345]

Thanks for all the help with this one guys. Yes I see your point with the wording, there are a lot of terms in engineering that can be considered something else if you have a dirty mind. Anyway, I heated the annulus and slowly tried to press the shaft in, however the shaft has buckled on insertion. :(

 

[dr dodge]

too much interference at ambient conditions
or
too big a hammer
sorry it didn't work

dr