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Hollow shaft advice needed

We have a hollow shaft 1.5"OD (38.1mm) turned down on part of its length to 35mm to fit the ID of a ball bearing. This leaves a *very* shallow shoulder up agianst which the bearing inner race will press. We wish to beef this up with a short (about 3/4" long) piece of 1.5"ID tube and have thought of three methods to fix this sleave on the shaft: 1) Pin it with a 1/4" to 3/8" roll pin. Which size? 2) Four generous tack welds (TIG - 309SS filler) spaced evenly around the shaft on the end away from the bearing. 3) Shrink the sleave on. 500F difference should give us about

0.0075" expansion of the sleave. 4) some combination of the above.

Question: Which of these will do the least harm to the integrity of the shaft?

Other suggestions?

Ted

Reply to
Ted Edwards
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What are you trying to achieve with the shoulder you plan on adding there - if you want to stabilize the bearing from rocking, I would not worry about it, because if the bearing is a snug (shrink) fit on the shaft, it won't rock. If the aim is to provide extra strength to prevent the bearing from shearing the shoulder and sliding down the shaft, I think there's already enough meat there to do that.

So I could not really pick one of the above without knowing the overall goal in mind.

The tack welds will probably distort the shaft, and if you are machining for the bearing bore to a reasonable degree of accuracy, that will mess that up. Unless you turn it after welding.

The roll pin option will of course occlude the bore of your hollow shaft.

The shrink fit option would be the least intrusive, but would be a bit of a hassle to implement. Also consider that if the wall of the shaft is thin enough, and you machine the bearing seat before shrinking the sleeve on, and the interference is large, you may wind up having to correct for the bearing seat being undersized by a few tenths near the shoulder, because of the shrink force.

Jim

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Reply to
jim rozen

Silver solder

Dan

Reply to
Dan Caster

Go to

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and get a free sample snap ring, the kind without ears. Don Warner

Reply to
Don Warner

You want a piece of tubing to go inside the tubing that you have. Do a plug of at least 2x the width of the bearing and shrink it in is going to be the best. Another choice is to go for a different bearing if possible that is larger ID and use that. You may end up making a shim piece and only turning the end a little bit and thus getting the full strength of the tubing without problems. Taking .010" off of the tube and then using a .006" shim stock between the bearing and the tubing will give a nice bit of interference fit and the bearing shouldn't come off.

-- Bob May Losing weight is easy! If you ever want to lose weight, eat and drink less. Works evevery time it is tried!

Reply to
Bob May

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