Journal of Failure Analysis and Prevention

, Volume 6, Issue 6, pp 25–31 | Cite as

Failure analysis of an aero engine ball bearing

  • N. Ejaz
  • I. Salam
  • A. Tauqir
Case Histories


An aero engine failed due to the misalignment of the ball bearing fitted on the main shaft of the engine.

The aero engine incorporates two independent compressors: a six-stage axial flow low-pressure compressor and a nine-stage axial flow high-pressure compressor. The bearing under consideration is a high-pressure-location bearing and is fitted at the rear of the nine-stage compressor. It was supposed to operate for at least 5000 h but failed catastrophically after 1300 h of operation and rendered the engine unserviceable.

Unusually high stresses caused by misalignment and uneven axial loading resulted in the generation of fatigue crack(s) in the inner race. When the crack reached the critical size, the collar of the race fractured, causing subsequent damage. The cage also failed due to excessive stresses in the axial direction, and its material was smeared on the steel balls and the outer race.


aero engine component ball bearing bearing steel fatigue misalignment tool steels 


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Copyright information

© ASM International - The Materials Information Society 2006

Authors and Affiliations

  • N. Ejaz
    • 1
  • I. Salam
    • 1
  • A. Tauqir
    • 1
  1. 1.KRLRawalpindiPakistan

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