Failure Mechanisms of Ball Bearings Under Lightly Loaded, Non-Accelerated Usage Conditions

Tribology International, Vol. 81, pp. 291-299, 2015, DOI: http://dx.doi.org/10.1016/j.triboint.2014.09.014

Failure Mechanisms of Ball Bearings Under Lightly Loaded, Non-Accelerated Usage Conditions

Hyunseok Oh ¹, Michael H. Azarian ¹, Carlos Morillo ¹, Michael Pecht ¹, and Edward Rhem ²
¹CALCE, Center for Advanced Life Cycle Engineering, Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20740, USA
²Dell Inc., One Dell Way, Round Rock, TX, 78682, USA

Abstract:

This paper identifies the failure mechanisms of ball bearings in low-power motors for electronics cooling. This study contrasts with previous studies on bearing life in its precipitation of failures under lightly loaded,non-accelerated usage conditions that are more representative of electronics cooling applications. Life tests were conducted on bearings composed of steel balls,steel inner and outer races, and a glass-fiber reinforced polyamide cage.Failure analysis of the ball bearings indicated that lubricant loss, transfer film formation,and wear particle generation were the failure mechanisms.Severe wear was found in the glass-fiber reinforced polyamidecages after failure.Several features extracted from the acoustic emission signals were identified as indicators of bearing degradation.

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