Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Bearings and bushings.

  1. Jul 12, 2012 #1
    I'm currently finding a bearing or bushings that can work underwater without a housing with minimal rust. Do anyone have an idea if it can? If there is, pls give me the details of the bearings or bushings?
     
  2. jcsd
  3. Jul 12, 2012 #2

    Mech_Engineer

    User Avatar
    Science Advisor
    Gold Member

    It's hard (or impossible) to give you really useful feedback without some sort or information about the application... but I'll wager a guess at stainless steel bearings? I think oxidation will be less of a problem than lubrication under water though.
     
  4. Jul 12, 2012 #3
    But won't stainless steel still rust that fast? I resesrched and found that it still rust. My application would be using a bearing or bushing that is attached to a shaft for a motor tp run underwater. The equipments will be placed underwater for quite a long time
     
  5. Jul 12, 2012 #4

    Mech_Engineer

    User Avatar
    Science Advisor
    Gold Member

    It depends on what stainless you're using, and what the "water" is (I'm assuming you mean salt water?). Stainless 316 is a marine-grade stainless steel and pretty tough stuff. It could give you a pretty high resistance to corrosion, but no stainless is 100% corrosion proof.

    Of course if you're talking salt water (or any electrolyte), you also need to worry about Galvanic Corrosion. Are you aware of the difference?

    http://en.wikipedia.org/wiki/Galvanic_corrosion
     
    Last edited: Jul 12, 2012
  6. Jul 12, 2012 #5
    Is there a known bearing that is made up from stainless steel 316? Btw bearings needs oil to be lubricated..So is it impossible to place it under sea water? Is there a way to use bearings underwater
     
  7. Jul 12, 2012 #6

    Mech_Engineer

    User Avatar
    Science Advisor
    Gold Member

    Bearings are of course used underwater in all kinds of applications, as far as I know the "best practice" way to do it is to seal them from the water using o-rings and gaskets. This also allows retention of lubrication.
     
  8. Jul 12, 2012 #7
    I'm seriously becoming desperate. I need a bushing or bearing that is able to work without sealing it. Is there really nothing that can work underwater just like that?????
     
  9. Jul 13, 2012 #8
    Shaft and bushing underwater

    Recently i found a polyacetal bushing from Misumi and planning to use it for my underwater application(please do tell me if it can't be use when submerged in sea water). I'm planning to a attach it to a stainless steel shaft which will be rotated by a motor. Do u think it will work? Enlighten me pls.
     
  10. Jul 13, 2012 #9

    Bobbywhy

    User Avatar
    Gold Member

    Re: Shaft and bushing underwater

    malek340, To discover if your polyacetal bushing will survive the stainless steel motor shaft and the saltwater environment it seems to me the logical place to find out is Misumi Customer Service. If you are in the USA you might call them and ask:
    MISUMI USA
    1717 Penny Lane, Suite 200
    Schaumburg, IL60173
    USA
    Phone 1: (847) 843-9105
    Phone 2: (800) 681-7475

    Cheers,
    Bobbywy
     
  11. Jul 13, 2012 #10

    Bobbywhy

    User Avatar
    Gold Member

    There are lots of mechanisms already rotating shafts underwater through a saltwater-impervious bushing. Ships, boats, outboard motors, pumps, directional sonar arrays are just a few examples. What do they use?
     
  12. Jul 13, 2012 #11
    I just recently found out about polyacetal bushing but am not too sure yet. Any thoughts?
     
  13. Jul 13, 2012 #12

    Mech_Engineer

    User Avatar
    Science Advisor
    Gold Member

    There's just no way to give you any more specific information without knowing SOMETHING about your application...
     
  14. Jul 13, 2012 #13
    Have you thought about Lignum Vitae?
     
  15. Jul 14, 2012 #14

    etudiant

    User Avatar
    Gold Member

    Ceramic bearings are becoming pretty routine and should be quite salt water resistant.
    However, I believe they are currently offered primarily in small sizes.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Bearings and bushings.
  1. Bearings question (Replies: 2)

  2. Strange bearings (Replies: 1)

  3. Bearing preload (Replies: 4)

  4. Bearing Stresses (Replies: 5)

Loading...