plastic in place of sae 660 bronze?
plastic in place of sae 660 bronze?
(OP)
Hi
I am hoping someone may be able to help
I have a shaft on the end of a roller that is 100 mm
in diameter and I need a bearing/pillow block to fit it.
The problem is the area where the bearing goes is
8" wide by 8" high by 4" thick.
I have been throught most of the books and all are
too big.
Fairly heavy load,slow turning,near salt water and sea mud.
(sea wall roller on the back of a deep sea dragger)
We are now using SAE 660 bushings* in split blocks, but only getting 4-6 months out of the bushings
** Wondering if some type of PLASTIC would work**
*bushing are 100 mm x 120mm x 95mm
take care
eddie
I am hoping someone may be able to help
I have a shaft on the end of a roller that is 100 mm
in diameter and I need a bearing/pillow block to fit it.
The problem is the area where the bearing goes is
8" wide by 8" high by 4" thick.
I have been throught most of the books and all are
too big.
Fairly heavy load,slow turning,near salt water and sea mud.
(sea wall roller on the back of a deep sea dragger)
We are now using SAE 660 bushings* in split blocks, but only getting 4-6 months out of the bushings
** Wondering if some type of PLASTIC would work**
*bushing are 100 mm x 120mm x 95mm
take care
eddie






RE: plastic in place of sae 660 bronze?
Nylon, Acetal, Polyester or UHMWPE or Xlinked PE could all work depending on load and speed and lubrication/cooling.
Fairly heavy and slow turning is no where near a good enough description to hazard a decent guess.
You should be able to buy any of the above as rod or block form big enough to machine your bearings, some with things like silicone oil or Teflon or carbon fibre or Kevlar pup or graphite powder or molybdenum di sulphide powder or bronze powder or some combination of whatever works for the particuar plastic.
If the pressure and speed is high enough to melt some plastics, you will need a higher melting point plastic.
If they pound out, you will need a better creep resistance and tensile strength.
If they are cut up by grit, you will need a softer tougher polymer.
How many do you need, if there are commercial volumes (like 100s at a time) there might be better methods of production, like a small run in an existing pipe fitting mould or having a mould made. Moulds are very expensive, but parts from it will be cheaper.
Regards
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.
RE: plastic in place of sae 660 bronze?
Try TriStar http://www.tstar.com/default.asp or Professional Plastics http://www.professionalplastics.com/
RE: plastic in place of sae 660 bronze?
Try PEEK (PolyEtherEtherKetone) - if that does not work you are probably out of plastics to choose from.
Here is a random site off a Google search for "PEEK Machined parts" Halfway down is mention of a bearing grade. Plenty of hits.
I have assumed you are in the USA: http://tinyurl.com/5td5hd
Cheers
Harry
RE: plastic in place of sae 660 bronze?
The link says he is in Canada.
I keep discounting PEEK on a cost basis, even though I sold it for ICI back when. Do you still even remember ICI.
For an application like this it is a valid consideration as material cost is probably a very small portion of the total bearing replacement cost.
Regards
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.
RE: plastic in place of sae 660 bronze?
For these sort of postings I always assume "one off" as the op does not state otherwise, and "the back of a deep sea dragger" implies low volume (e.g 1)
After my posting above I did some searching and 2" is about the biggest diameter available in PEEK. Looks like a segmented bearing with a retainer cage might do the job.
Attached is a TIFF file of such cage. (I think!)
Cheers
Harry
RE: plastic in place of sae 660 bronze?
Oops, TIFF file attached...
H
RE: plastic in place of sae 660 bronze?
Regards
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.