Failure Analysis of a Helicopter's Main Rotor Bearing

Abstract:

Presented results report some of the findings of a detailed failure analysis carried out on a main rotor hub assembly, which had symptoms of burning and mechanical damage. The analysis suggests environmental degradation of the grease which causes pitting on bearing-balls. The consequent inefficient lubrication raises the temperature which leads to the smearing of cage material (brass) on the bearing-balls and ultimately causes the failure. The analysis has been supported by the microstructural studies, thermal analysis and micro-hardness testing performed on the affected main rotor bearing parts.

• Periodical: Key Engineering Materials (Volumes 510-511)
• Pages: 399-405
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.510-511.399
• Online since: May 2012
• Authors: M. Shahzad, A.H. Qureshi, H. Waqas, N. Hussain, L. Ali
• Keywords: Ball Bearing, Failure Analysis, Pitting, Smearing

References

[1] Bearing failures and their causes, Document ID 401, SKF.

[2] J. Cappel, M. Weinberg, R. Flender, Steel Grips, 2 (2004) 261–268.

[3] Precision cages for spindle, turbine, miniature and instrument ball bearings, Barden Corporation, 200 Park Avenue, Danbury, CT, USA.

[4] H.K.D.H. Bhadeshi, Progress in materials science, 57 (2012) 268-435.

[5] E. N. Bamberger, Status of understanding for bearing materials (n–84–25047 15–37). in Tribology in the 80's, volume 2, pages 773–794, Cleveland, Ohio, USA, (1984).