Sintered Bush bearing design

...we know! Telling the truth as a joke!!

Sintered bronze bushings are not generally recommended for stainless steel shafts. The failure mode is galling and locking up. Hardening the stainless steel will help a little. Note that a sintered bronze bearing will not develop as strong a load carrying film as a plain leaded bronze bearing with the right lubricant supply and good alignment and size control.

Are you dealing with a turbocharger application? There's a lot of well proven art in that area and you would do well to respect that.

What is your shaft diameter? If you get into really high DN numbers you may be looking at tri-lobe bearings. That's far out.

Ed Weldon

Hardening SS?

I don't think that will work, just as a side comment.

Regarding the original question and given rpm, we sure need to know the shaft diameter as it is the velocity that counts. Just too skimpy info provided in the question. Load? Ratio of width to diameter? running 24 hours / day? what is life expectancy, environment, oil supply, etc, etc.

RE: stainless steel shafting for a bronze oil lubricated bearing (sintered or solid)

I agree. Stainless steels of any kind are inferior to a carbon or low alloy steel. Hardness in stainless steel is not the answer although there are some indications that high hardness 440C as well as nitrided 304 help a little to deter galling. 17-4 ph, even with its greater hardness than 304 or 316, is a particularly poor choice.

There is one possible exception, Nitronic 60. One of the few stainless steels that has high strength and good anti galling properties. Readily available in bar stock form, even on ebay.

Here's a post from another forum, "Engineering Tips Forum"
http://www.eng-tips.com/viewthread.cfm?qid=144638&page=1

"haze10 (Electrical) 13 Jan 06 17:50
I am trying to select a sleeve and bushing material. Operation is a bottom auger for a large chemical vat processing paint pigment, 50% solids and water, somewhat abrasive. There is a large universal joint at the bottom that drives the auger. ........."

Way down at near the last answers Rorschach makes the comment: "Your best bet would be toughmet or Ampco 45 (aluminum nickel bronze) mated to N60 IMHO."

This fellow, Rorschach, rates pretty high in credibility in my book.

Anyhow, are we on the right track here? We still need to hear from vckswamy about more details on his application. Why does he consider the use of stainless steel for a shaft? Does he really have a corrosion problem or is the material selection simply one of convenience?

Ed Weldon

Not a good idea!

If stainless steel, then 13 to 18%chromium and low nickel - non austenitic- for example 440C as used in stainless ballbearings.

SIntered : no, not suitable for high velocity.

Hydrodynamic: yes.

RHABE