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Journal of Failure Analysis and Prevention

, Volume 11, Issue 6, pp 631–635 | Cite as

Case Study on Failure of Ball Bearing of an Aeroengine

  • R. R. Bhat
  • Vaisakhi Nandi
  • V. Manohara
  • S. V. Suresh
Case History---Peer-Reviewed

Abstract

Heavy damage was reported on the outer race and rolling elements of a ball bearing belonging to jet engine of a military aircraft. Flaking type of damage was noticed only at one particular location on the outer race of the bearing and on almost all the balls of the bearing. The inner race and the cage of the bearing were free from any damage. The chemistry, hardness, and microstructure of the bearing components met the specification requirements. In the actual engine assembly, the bearing was mounted on shaft of bevel gear. Careful examination of the inner diameter (ID) of the inner ring of the bearing revealed nonuniform contact marks. The contact marks were observed in the form of discoloration of the ID surface. The nonuniform contact was attributed to eccentricity caused by improper mounting of the bearing onto the shaft of the bevel gear. This resulted in preferential loading, causing flaking at one particular location on the raceway of the outer ring and damage to the balls of the bearing. Hence, it was concluded that the ball bearing had failed because of assembly error after the last repair of the engine.

Keywords

Aircraft Bearing failure Failure analysis Spalling Scanning electron microscope 

Notes

Acknowledgments

The authors express their sincere gratitude to Shri S.P. Singh, General Manager (Foundry & Forge Division) for his constant encouragement and support in conducting failure analysis work in the laboratory and for permitting us to publish the case study.

References

  1. 1.
    Failure of rolling element bearings. In: Failure Analysis and Prevention, vol. 11, ASM Handbook, pp. 501, 503–504. ASM International, Materials Park, OH (1995)Google Scholar
  2. 2.
    Failure of rolling element bearings. In: Failure Analysis and Prevention, vol. 11, ASM Handbook, pp. 494, 502–503. ASM International, Materials Park, OH (1995)Google Scholar
  3. 3.
    SKF Product Information 401: Bearing Failures and Their Causes, p. 28. Palmeblads Tryckeri AB, Sweden (1994)Google Scholar
  4. 4.
    Ball & Roller Bearings: Failures, Causes and Countermeasures, JTEKT Corporation, Cat. No. B3001E, pp. 4–5. Soy Ink, Japan (2009)Google Scholar

Copyright information

© ASM International 2011

Authors and Affiliations

  • R. R. Bhat
    • 1
  • Vaisakhi Nandi
    • 1
  • V. Manohara
    • 1
  • S. V. Suresh
    • 1
  1. 1.Central Materials and Processes Laboratory, Foundry and Forge DivisionHindustan Aeronautics Limited (HAL)BangaloreIndia

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