Journal Bearing Design - Does anyone use Raimondi & Boyd?
Journal Bearing Design - Does anyone use Raimondi & Boyd?
(OP)
I've been teaching ME students the use of Raimondi & Boyd's Sommerfeld number -> dimensionless variable charts for years. The method is in every machine design text, but I am curious as to if anyone actually uses it in practice. It doesn't appear to have changed much since 1958. I would appreciate hearing from folks who use it, and also from current alternative methods of journal design - even if it is commercial or proprietary software.





RE: Journal Bearing Design - Does anyone use Raimondi & Boyd?
RE: Journal Bearing Design - Does anyone use Raimondi & Boyd?
I'm just trying to find out if anyone actually uses these!
RE: Journal Bearing Design - Does anyone use Raimondi & Boyd?
I just checked out that link and it is a good summary. It has the same information as in Shigley, but the equation for temperature rise is different. They both give different answers. I don't know which is right, but the one in the link contains density and specific heat which do not appear to be included in Shigley's equation. Do you have any thoughts on this?
PS- I learned this method from an old timer that used to work at GM so it must have been used for engines. Of course today everything is programmed and nobody knows how to do anything. Are you familiar with journal orbit analysis? I will look up the name of the paper if you want it.
Thanks,
John Woodward
RE: Journal Bearing Design - Does anyone use Raimondi & Boyd?
RE: Journal Bearing Design - Does anyone use Raimondi & Boyd?
I looked at Shigley (5th Ed) on page 504, and it looks like equations a. and c. when combined will give the same deltaT equation in the link's Step 13. Shigley uses C sub H for specific heat, while the UTM equation uses C sub p. And Shigley uses gamma for weight per unit volume, while the UTM equation uses rho. Finally, Shigley explicitly shows J as the mechanical equivalent of heat (9336 lb.in. per BTU) in his equation, while the UTM method just "quietly" includes the factor - but says that they use it.
It looked to me that both methods were really the same and should give the same answer. Let me know what you think.
To TZSiR -
It sounds like you may be practicing "intuitive" design. I have seen students use this method on exams, but without the success that you seem to have had!