quote:
Originally posted by 1911:
I'll look in one of my Mech E text books at work this week and perhaps give a more comprehensive answer but I can tell you the following off of the tip of stainless 1911 barrel:
If you look at film thickness equations you will not see the bearing clearance mentioned.
You cannot simply lower the clearnce a ton and then use water thin oil and expect to get an oil wedge to form. Each bearing has a characteristic number which is related to the lube viscosity times the rotational speed divided by the radial load. This number relates directly to the tendency or ability for a hydrodynamic film to develop. IF this number is not at a certain value, you can kiss a good stable protective film goodbye.
Thus I believe the low clearance statement justifications for the use of thin oils are utterly ridiculous. A film will not develop unless there is sufficient speed and viscosity whether the clearance is low or high.
1911