Does anyone have any comments as far as how I have designed the lower bearing assembly that I plan on installing on my home built longtail? Any better components to use comments would be appreciated.

This is a DRAFT copy. Revisions will have to be made for proper function

What CAD are u using?

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Autodesk Inventor 2012

Neat. It seems pretty legit. Any reason you used a single tapred roller bearing? Typically you see 2 where they oppose each other to keep a balance. I see you have the lock collar to push the bearing against on the back side so that will keep it all in check and preload that bearing a little bit. Wouldnt it be easier to just use a straight needle roller bearing?

Not sure why you would want two bearing opposing each other, but it may be a good idea in case you jam the shaft from the aft end. I don't have much experience with bearings, etc. It would be easy enough to revise. I think I saw someone mention tapered roller bearing somewhere.

The Prop is on the right side.

so put another tapered bearing at the upper part of the shaft near the engine pointed the opposite direction, and adjust the compression of the bearings with a nut pushing on another collar, also at the top?

Think of the shaft as the moving part and the bearing housing as the non moving. With prop thrust, you'll have force against the shaft which is "unloading" the tapered bearing per this design. The tapered bearing needs to be flipped which will change the current design. You also don't have a way to set the tension on the tapered bearing (like a spindle nut on a trailer bearing).

No need for a tapered roller bearing. Simply use 2 single row ball bearings or a single needle bearing with an inner race. Do not try to use needle bearing directly on the shaft, unless you are using hardened, centerless ground stock. Why have 2 pieces to the housing? Simply make a housing that can be welded or threaded to the drive housing tube and then insert the bearings and seals from the prop side. Use your cap that you have already desinged to retain everything. You can add a step or reatining collar to the shaft to take some of the thrust load but I have never had any problems transfering that energy into the u-joint and engine output shaft. Steps in the shaft just add stress concentrations. If you feel you need it, it may be easier to lock the thrust force at the top bearing by using an extended inner race bearing and a set screw.

Mag10

Hmmmmm. Let me see ehat parts I can find in Mcmaster

The problem I am having is that the bearings are larger diameter than the seals, which means the bearings must be locked into place with a second housing aft for the seals.

second try

Timken P/N 470390
NATIONAL Part # 470390 Nitrile Seal, Shaft Size=0.75", Housing Bore=1.874, Outer Diameter=1.878, Width=0.25in
$5.50 ea at www.rockauto.com

Also your bearings are only $4.01 at RockAuto.com
TIMKEN Part # SET2 Wheel Race; Qty 1 Required Per Wheel, 3/4" bore 1.781"OD

http://www.rockauto.com (my favorite parts house!)
1.png
Select Parts Number Search
2.png
Type in SET2 as your bearing part number
3.png
voila!

OK, here is where I am at now. Thanks all for the help with the seals. I have more to do, but this is now much simpler

as long as youhave another bearing like that on the TOp of the shaft where the Cones FACE each other like 50hptiller posted earlier you have something simple that will work.

You will have a solid setup.

Looks pretty good actually

Might do that to mine now...

Turn down a nut into a sleeve, It can act as the collar to hold the bearing in place on the shaft as well and give you a surface to run the seals on. Try to make the housing large enough so you can run a real spring loaded double lip seal. They seal a lot better and will keep water out your bearing.

beavertail has a similar setup without tapered bearings. The problem I see is the nuts trying to loosen or tighten as the shaft turns. I think the seals should be in the outer cap like beavertail does.

Ok, total re-design based on the beavertail diagram. Easier to machine also I think. Whadda y'all think?

You need that retaining ring on the shaft, not the housing. The thrust from the prop is not being supported anywhere. Also I would look for a larger bearing rather than three skinny ones.

Have you ever bored or internally threaded 316? Not gonna be an easy task.

Here is my set up. I have not finished yet though.
MM Front.jpg
MM rear.jpg

Yall are way over-thinking this. Find a ball bearing with a 1.625" OD to match the 1.625" OD seals. I have just purchased some of these from Fastenal in the last 2 months. I believe they were Fit (brand) bearings. Create a single bore that will house 2 bearings and 2-3 seals. The cap will simply thread into that same bore and retain these components. The thrust will be absorbed as a side load into the bearings and bearing housing and also into the u-joint. If your u-joint will take the rpm it will be more than adequate to take this thrust force unless you are planing on putting 60 hp or more to this outdrive.

Sandor27, you may want to re-think the hollow drive shaft. There is a reason that most people and businesses are using 80 + KSI material in their mud motor drive shafts.

This is my current Rev E design. 3 sets of Bearings are probably overkill, LOL. But it should work. The small groove just aft (to the right) of the bearings is for a retaining ring.

get rid of zerk add 1 more seal turned the other way to keep water out. Put a 1/6 inch nylon thrust washer between seal cap and threads.

sorry 1/16 thrust washer

So get rid of the o-ring and add a nylon washer? Also add one more seal to total 3?

If you do not own a machine shop you can not build the bearing seal houseing cheaper than buying from beavertail.

Keep in mind if you are threading your bottom housing onto the drive tube you need to use left hand threads or the bearing housing can unscrew while you are running. I had this happen years ago. If you dont want to use LH threads you could tack weld the bearing housing to the drive tube