TY - GEN
T1 - A metallurgical and experimental investigation into sources of warm bearing trending
AU - Tarawneh, Constantine M.
AU - Cole, Kevin D.
AU - Wilson, Brent M.
AU - Reed, Martin
PY - 2008
Y1 - 2008
N2 - In the railroad industry, bearing hot-box detectors are the primary tools utilized for the removal of distressed bearings from service. Current technology has expanded the role of these detectors to monitor bearings that appear to "warm trend" relative to the average temperatures of the remainder of bearings on the train. Several bearings set-out for trending and classified as non-verified revealed that a common feature was discoloration of rollers within a cone assembly. A number of laboratory tests were performed to determine a minimum temperature and environment needed to reproduce these discolorations. In addition, a metallurgical examination concluded that microhardness profiles from discolored rollers exhibited evidence of heating, which lead to softening of the case microstructure, and a reduction in case depth. In order to determine a cause for the internal heat leading to the discoloration of rollers, selected laboratory experiments were carried out in a simulated service environment. Testing focused on exploring certain defects or hypothetical scenarios that may raise the bearing cup temperature above that of normal operating conditions. None of the examined cases resulted in similar roller discolorations to those observed in the trended set-outs. The studies presented in this paper comprise the initial work aimed at determining the root cause of warm bearing trending that some tapered roller bearings experience during service.
AB - In the railroad industry, bearing hot-box detectors are the primary tools utilized for the removal of distressed bearings from service. Current technology has expanded the role of these detectors to monitor bearings that appear to "warm trend" relative to the average temperatures of the remainder of bearings on the train. Several bearings set-out for trending and classified as non-verified revealed that a common feature was discoloration of rollers within a cone assembly. A number of laboratory tests were performed to determine a minimum temperature and environment needed to reproduce these discolorations. In addition, a metallurgical examination concluded that microhardness profiles from discolored rollers exhibited evidence of heating, which lead to softening of the case microstructure, and a reduction in case depth. In order to determine a cause for the internal heat leading to the discoloration of rollers, selected laboratory experiments were carried out in a simulated service environment. Testing focused on exploring certain defects or hypothetical scenarios that may raise the bearing cup temperature above that of normal operating conditions. None of the examined cases resulted in similar roller discolorations to those observed in the trended set-outs. The studies presented in this paper comprise the initial work aimed at determining the root cause of warm bearing trending that some tapered roller bearings experience during service.
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M3 - Conference contribution
AN - SCOPUS:69949147096
SN - 0791848124
SN - 9780791848128
T3 - Proceedings of the ASME/IEEE/ASCE Joint Rail Conference, JRC 2008
SP - 99
EP - 107
BT - Proceedings of the ASME/IEEE/ASCE Joint Rail Conference, JRC 2008
T2 - ASME/IEEE/ASCE Joint Rail Conference, JRC 2008
Y2 - 22 April 2008 through 24 April 2008
ER -