Thrust bearing for a marine application

Lowlysubaruguy

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Im getting ready to build a Furling for my buddies sail boat. It will require one possibly two thrust bearings or washers on its internal cone. The thrust load will be moderately high but RPMS will be low. It will see direct ocean spray rain and elements.
If you dont know a Furling is a basically a caged spool that rope allowing a sail to roll in and out ( open or closed) so its a pulley that allows this rope to move freely at a sail.

It will be made out of aluminum and the assembly will be about 8” long and 6 or 7 “ in diameter the spool will live inside this. id love it if I could find a needle or ball bearing thrust bearing assembly that salt water will not harm but it seems to be harder to accomplish than I had hoped. I still have yet to find a bearing that is made of the appropriate stainless to survive. There is possibly a supplier in the UK but im hoping to find something id see in a week. I could machine brass washers for this or even just utilize a thrust washer for a propeller but a roller bearing would allow for much less friction. I am thinking if I have to make a flat thrust washer id drill through the hub and create a greaseable fitting for it so it could be lubed periodically.

Any thoughts are appreciated
 
Im getting ready to build a Furling for my buddies sail boat. It will require one possibly two thrust bearings or washers on its internal cone. The thrust load will be moderately high but RPMS will be low. It will see direct ocean spray rain and elements.
If you dont know a Furling is a basically a caged spool that rope allowing a sail to roll in and out ( open or closed) so its a pulley that allows this rope to move freely at a sail.

It will be made out of aluminum and the assembly will be about 8” long and 6 or 7 “ in diameter the spool will live inside this. id love it if I could find a needle or ball bearing thrust bearing assembly that salt water will not harm but it seems to be harder to accomplish than I had hoped. I still have yet to find a bearing that is made of the appropriate stainless to survive. There is possibly a supplier in the UK but im hoping to find something id see in a week. I could machine brass washers for this or even just utilize a thrust washer for a propeller but a roller bearing would allow for much less friction. I am thinking if I have to make a flat thrust washer id drill through the hub and create a greaseable fitting for it so it could be lubed periodically.

Any thoughts are appreciated

I don't know about a thrust bearing, but I think ceramic bearings will survive. But they are very expensive.
 
Need to look for some 454 navel bronze. don't recall the British Standard number for this, just Google Navel bronze. Be the only material I would recommend for bearing material exposed to salt water.
 
Oops, that should be 464 Navel Bronze. Sorry.
Ken
 
I hope you are doing this for the build because you can and not to save money . It would be a waste of time to do all of this and then not anodize , and as I'm sure you know hard coat anodize is $$$! Also how would you make the forstay spar ? If you must pursue this Harken makes Torlon ball bearings , they used to sell a complete race . http://www.harken.com/productdetail.aspx?id=4943&taxid=1610 I'm interested in this because I love all things sailboats , what is the size of the boat ? re read your post about grease , forget about it . We have a furling unit on our boat called a Pro Furl . It works well , but we use the boat lightly (although I bought it 20 yrs. ago) . I have been reading of people that have this rig and they have converted over to Trolon bearings . Original Pro Furl rig came with grease packed SS bearings .
 
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If you happen to have any more questions, a good friend of mine has done a LOT of sail boat building from scratch. He just sold his last motor sail boat for $80K. I helped him with a few of the machining projects. be glad to get you in touch with him.

Karl
 
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