How Does Fluid Viscosity Affect Bearing Wear in Lubricated Systems?

Click For Summary

Discussion Overview

The discussion revolves around the relationship between fluid viscosity and bearing wear in lubricated systems, specifically focusing on how viscosity may influence fatigue wear in carbon bearings under varying pressure conditions. The scope includes theoretical considerations, potential formulas, and practical implications in engineering contexts.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant inquires about a formula that relates viscosity, pressure difference, and bearing wear, suggesting a need for a quantitative approach.
  • Another participant expresses uncertainty, indicating that while hydrodynamic equations can describe lifting forces based on pressure and viscosity, linking these to fatigue wear is complex and likely requires experimental validation.
  • A different participant notes that lubricant selection typically focuses on load factors and shear strength rather than directly quantifying wear, mentioning existing formulas for bearing and lubricant life without providing specific connections to viscosity.
  • A follow-up question asks how the viscosity of the fluid affects the force on the bearings, emphasizing the perpendicular force acting on the shaft.

Areas of Agreement / Disagreement

Participants do not reach a consensus on a specific method to quantify the relationship between viscosity and bearing wear. Multiple viewpoints exist regarding the complexity of establishing this relationship, with some suggesting experimental approaches while others focus on existing theoretical frameworks.

Contextual Notes

Limitations include the lack of specific formulas that directly relate viscosity to fatigue wear, the dependence on experimental data for validation, and the potential variability in lubricant performance based on different operational conditions.

Who May Find This Useful

Mechanical engineers, researchers in tribology, and professionals involved in bearing design and lubrication systems may find this discussion relevant.

meterman
Messages
5
Reaction score
0
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
 
Engineering news on Phys.org
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.
 
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
 
Last edited by a moderator:
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?
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
4K
  • · Replies 5 ·
Replies
5
Views
6K
Replies
0
Views
3K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 28 ·
Replies
28
Views
5K
  • · Replies 15 ·
Replies
15
Views
3K
  • · Replies 3 ·
Replies
3
Views
3K
Replies
9
Views
4K
Replies
5
Views
5K