Bearing Friction

Nov. 15, 2002
The frictional properties of any plain bearing depend on the lubrication system.

The frictional properties of any plain bearing depend on the lubrication system. Either hydrodynamic or hydrostatic lubrication can provide low friction. Gas bearings have the lowest friction levels.

Friction in hydrodynamic and hydrostatic bearings is a function of lubricant viscosity and shear rate. Shear rate increases with increasing rotational speed and decreasing film thickness. Friction coefficient is generally below 0.001.

Self-lubricated bearings vary widely. It is difficult to predict performance for a given bearing/lubricant system. The range of coefficients of friction is 0.01 to 0.10 for boundary lubrication and 0.01 to 0.3 for self-lubrication.

Caution must be used when applying friction coefficient handbook data. Conditions under which the values were measured should be known and duplicated in the application. Coefficient of friction tends to increase with increasing surface roughness, dryness, and cleanliness of surfaces, and decreasing temperature.

Sponsored Recommendations

June 27, 2025
Ensure workplace safety and compliance with our comprehensive Lockout/Tagout (LOTO) Safety Training course. Learn critical procedures to prevent serious injuries.
June 27, 2025
Join our expert webinar to discover essential safety control measures and best practices for engineering a truly safe and compliant industrial environment.
June 25, 2025
An innovative aircraft with electric drives combines the best of both worlds. The cross between drone and helicopter could mean significantly faster and more efficient air emergency...
June 25, 2025
Effective when other materials fail, ceramics are particularly suitable for applications requiring wear and chemical resistance, sliding characteristics or biocompatibility. Discover...

Voice your opinion!

To join the conversation, and become an exclusive member of Machine Design, create an account today!