FWM Project

Ball Bearing Study- Steel Balls –vs- Ceramic Balls

FWM Project- Surface

Ball Bearing Contact SurfacesSurface Roughness:Raceway~ 3AABall ~ 0.1- 1.0 AA

Surfaces are ground, honed and lapped.

FWM Project- ContactGeneralized Hertz Contact Case

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Steel-Steel Cermic-Steel

• Ball Bearings are referred to as “anti-friction” bearings because of the small amount of friction.

• Discuss sources of friction and relative amounts (effect of lubrication)

• Wear will not occur if there is proper lubrication• Discuss contact fatigue, Weibul charts and

method to calculate the L10 life of ball bearings

FWM Project- Friction, Wear, Contact Fatigue

• Discuss the differences in the minimum film thickness required for each material (based on composite surface roughness)

FWM Project- Elastohydrodynamic Lubrication

• Discuss the differences found between steel-steel and ceramic-steel contacts

• Compare with industry test results

• Make determinations on why the predictions do or do not match test results

FWM Project- Summary