Technical Reports

Performance of Degraded Roller Bearings

  • 18
  • Dec
  • 1989
AUTHOR: Kevin Kesler and Chris Tinto
OFFICE: RPD
SUBOFFICE: RPD-30
REPORT NUMBER: DOT/FRA/ORD-90/12
KEYWORDS: Roller Bearings; Bearing Thermal Performance; Degraded; Cone Rotation
ABSTRACT: Concerns over railroad bearing failure prompted a test to be conducted to measure the rate at which degraded bearings overheat under service conditions. A test consist which included a locomotive, a data collection car and four test cars containing 24 subject bearings was utilized. The bearings under test had all been removed from railroad service due to overheating. Two bearings were grooved and the remaining had differing interference fits. By monitoring t:he thermal performance of the bearings, the maximum heating and cooling rat:es associated with roller bearing failure were determined to be 12.8 deg/min and 7.2 deg/min, respectively. It was found that significant thernlal gradients can exist across a given bearing, with temperature differences of 30 deg F between inboard and outboard races. In addition, the cones associated with bearings that had minimal interference fit were observed to rotate at rates varying from •04 to 1.6 percent slip •

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