PDA

View Full Version : Bearing wear calculation


meterman
Oct1-04, 10:57 AM
Is there a way to relate the viscosity of a liquid to the fatigue wear of a bearing. The bearings are lubricated with the flow of liquid through the metering devise. The flow of liquid creates a perpendicular force on a shaft with carbon bearings on each end. Is there a formula that I can use that will incorporate the pressure difference in the flow of liquid and the viscosity of the liquid to help me figure out the wear on the carbon bearings

Clausius2
Oct1-04, 02:49 PM
I really don't know. Usually mechanical engineers tends to write down these subjects (and a lot of others) in tables or graphics adjunted with the bearings.

An analytical formulation has to involve the pressure, viscosity and wear to fatigue. Hidrodinamic equations can give you the lifting force exerted as a function of P and the viscosity, but relating this force with fatigue is more complex. It would to be done experimentally.

Sorry, I cannot help you so much. Maybe try to contact with the bearing manufacturer.

Chronos
Oct2-04, 12:56 PM
I am not aware of any method to quantify bearing wear on such a basis. Lubricant selection is typically based on the load factor which will tell you how much shear strength [viscosity] is needed to prevent metal to metal contact. This may not be helpful, but, there are formulas for calculation bearing and lubricant life.
http://www.noria.com/learning_center/category_article.asp?articleid=537&relatedbookgroup=OilAnalysis
http://www.bearingsindustry.com/aboutbearing/life.htm

meterman
Oct4-04, 01:44 PM
How does the viscosity of the fluid being pumped through the meter affect the force on the bearings, if the force is perpendicular to the shaft with bearings on each end?