Rate of Freeze-fitting shrinkage
Rate of Freeze-fitting shrinkage
(OP)
Hi
I work for an excavator bucket manufacturing company and we do a lot of Freeze-fitting on the bushes. I have come across a continuous issue regarding the fitting of some of the bushes as we can't work out how the bushings behave when frozen i.e. how much they shrink by, using liquid Nitrogen. Most of the bushes are made out of phosphor bronze or steel
I was wondering if there is a way to predict/work out the shrinkage rate of such material over a given diameter and wall thickness so that we could work out the tolerances accordingly.
I work for an excavator bucket manufacturing company and we do a lot of Freeze-fitting on the bushes. I have come across a continuous issue regarding the fitting of some of the bushes as we can't work out how the bushings behave when frozen i.e. how much they shrink by, using liquid Nitrogen. Most of the bushes are made out of phosphor bronze or steel
I was wondering if there is a way to predict/work out the shrinkage rate of such material over a given diameter and wall thickness so that we could work out the tolerances accordingly.





RE: Rate of Freeze-fitting shrinkage
http:
http://www.ameritherm.com/PDFs/shrinkfitcalcs.pdf
http://www.tribology-abc.com/calculators/e6_2.htm
RE: Rate of Freeze-fitting shrinkage
Look at a first year course in statics, deformation for example, and you will come across the equation: d=a(T')L. Deformation is a function of temperature change and length of the member. The linear coefficient is a number particular to the material properties in question.
Good luck with it.
Regards,
Cockroach
RE: Rate of Freeze-fitting shrinkage