sleeve bearing design

[rewindr]

I am interested in finding information on bearing designs. In particular I have found several cases where the oil wedge or side pocket in a sleeve bearing was inadequate and allowed the bearing to run hotter than normal. Making the wedge larger and deeper solved the problem. Are there any rules of thumb for oil wedge dimensions?

 

[electricpete]

Are you talking about the oil distribution groove? (The one that runs axially along the upper edge of the lower-half of the bearing.)

 

[jbartos]

Suggestions:
1. Visit

http://www.reliabilitydirect.com/appnotes/jb.html

etc. for more info
2. This Forum has some detailed postings pertaining to bearings. It is possible to search for them by a keyword under advanced search
3. This posting appears to be on the mechanical side. It may also appear under mechanical engineers in this Forum

 

[electricpete]

There is some discussion of oil distribution grooves in the "Tribology Handbook" by MJ Neale 1973

Section A11 for cranshaft sleeve bearings, and section B7 for other sleeve bearings. If you can get hold of that reference it may answer your questions.

The crank-case section states:
"Any hole, slot, or groove in the housing behind a bearing is dangerous because it promoates undesirable delection, fretting, and cracking."
I interpret this to mean you should be very careful if your groove goes beyond the babbit.

One thing I gather is that an axial groove should not extend the full length of the bearing (although it looks like it can come very close).

Partial circumferential grooves and axial grooves will both have an edge that lies in the axial direction. That edge should be smooth transition to avoid erosion of the surface downstream of the groove end.

There are 9 figures illustrating various aspects in the crankshaft sleeve bearing section and several more in the general sleeve bearing section. Tough for me to convey the whole thing to you without the figures. Also copyright restrictions would prevent me from copying it directly.

Maybe a bearing or equipment manufacturer or large motor rewind shop can provide some more info.

 

[rewindr]

Yes I am talking about the axial wedge that is usually in the lower half of the bearing. Typically I have seen it 1" wide on a 4" journal or so and is not quite as long as the bearing. Several times I have cured hot (160F) running bearings by making this groove a little deeper and a little wider. What I am looking for is any published data, rules of thumb or calculations I could make that would confirm that the groove detail is adequate.

 

[jbartos]

Suggestion to the previous posting. The above postings may need the addition of the tech support of your bearing manufacturer to be on the safe side.