Shaft seal

[dand0_4]

I know this has probably been addressed, but I couldnt find much about it. I am building a flat bottom aluminum boat with a trimmable surface drive, but I am not sure what to use for a shaft seal. Since the shaft will move up and down and mostly be above water level, I want to use the right part. The transom is 90degr. and the shaft will be running straight out the back to a cutlass bearing. It is a 1" shaft with a chevy 350 for power. Thanks

[fishon91]

mcmaster carr will have what you need.
any type of oil seal will work, but of course there are different ones for different applications. find one that suits your needs.

im not sure what to tell ya cuase im not sure how youre designing it.
if i was doing it, i'd put the shaft inside a housing, exactly like a car axle. there will be just a little bit of rotating shaft at the end of the tube, behind the prop.

[gonzo]

If it is out of the water, it will probably need to be lubricated and cooled with water. A dripless would work well

[CaptBill]

How about a high tech solution.
Make a ferrofluid bearing. No friction, no contacting parts, no wear, waterproof seal, no heat either. Plus this stuff has great dampening characteristics. Got access to a milling machine? They look simple enough to DIY.

I think what you might need would be a pivot joint like here
http://machinedesign.com/article/the...-bearings-1103

Gotta see this.....
http://www.youtube.com/watch?v=ULSG3pkjoT4

[CDK]

That would be the 1st ferrofluid bearing around a 1" shaft that runs at just a few thousand rpm.

I agree it looks simple, but that goes for a lot of things.

[CaptBill]

How about a ferrofluid chainplate deck opening/mounting. Imagine being able to pass a coin from the cabin to the outer deck. Could you MAKE water come below? Might be tricky. May not enen be possible. Dont know but shure would like to know.

[fishon91]

the shaft is coming out the transom, right? i see a lotta mudboats with the shaft comin out the bottom, not a true SD. i dont see the point in all the watercooled/ferrofluid design. whats wrong with keepin it simple and doing grease seals, bronze bushings, and marine grade grease? a pressure lunricator thing like godevil uses are pretty nice too. harder to find, just drill and weld nut to housing to install

i would definitely like to see more of your project cause i have plans to build a mudboat later in life, and i'm nosey..... ; )

[gonzo]

Poluting the waterways and breaking the Law

[fishon91]

illegal?? i've never heard that before.... thats how all the longtails and surface drive are done here in the south, actually all over the U .S. by mud motor companies.

i don't mean to sound like a J.A. know it all, but this isn't soundin realistic to me.