Accelerated Testing of UH-60 Viscous Bearings for Degraded Grease FaultAn accelerated aging investigation of critical aviation bearings lubricated with MIL-PRF- 81322 grease was conducted to derive an understanding of the mechanisms of grease degradation and loss of lubrication over time. The current study focuses on UH-60 Black Hawk viscous damper bearings supporting the tail rotor driveshaft, which were subjected to more than 5800 hours of testing in a heated environment to accelerate the deterioration of the grease. The mechanism of grease degradation is a reduction in the oil/thickener ratio rather than the expected chemical degradation of grease constituents. Over the course of testing, vibration and temperature monitoring of bearings was conducted and trends for failing bearings are presented.
Document ID
20150002701
Acquisition Source
Glenn Research Center
Document Type
Conference Paper
Authors
Dykas, Brian (Army Research Lab. Aberdeen Proving Ground, MD, United States)
Hood, Adrian (Army Research Lab. Aberdeen Proving Ground, MD, United States)
Krantz, Timothy (NASA Glenn Research Center Cleveland, OH United States)
Klemmer, Marko (Bundeswehr Technical and Airworthiness Center for Aircraft Manching, Germany)
Date Acquired
March 10, 2015
Publication Date
February 23, 2015
Subject Category
Mechanical EngineeringAircraft Design, Testing And Performance
Report/Patent Number
GRC-E-DAA-TN19830
Meeting Information
Meeting: Australian International Aerospace Congress (AIAC)
Location: Melbourne, Australia
Country: Australia
Start Date: February 23, 2015
End Date: February 26, 2015
Sponsors: Institution of Engineers, Defence Science and Technology Organisation