Applications of the Shock Pulse Technique to Helicopter Diagnostics.
Abstract
An investigation has been carried out on the feasibility of shock pulse techniques in the detection of failures in helicopter power trains. A standard off-the-shelf SKF Industries model MEPA-10A was employed to construct shock emission envelopes of shock rate versus shock level. Data was collected from the hanger bearings of the tail rotor drive shaft assembly, the 42 deg and 90 deg gear box assemblies, and the transmission and mast assemblies as installed on operational UH-1 series helicopters. Further data was obtained on the OH-58 as well as from helicopters at Fort Rucker, Alabama with implanted bearings of known condition. The correlation between the shock emission envelopes and degree of degradation as revealed by teardown analysis is described. Laboratory tests were conducted to determine the condition of the gears in the 42 deg gear box through the use of shock emissions. The shock pulse meter shows promise for its ability to separate those components with normal wear, or the onset of damage, from those with severe damage.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 24, 1975
- Accession Number
- ADA040130
Entities
People
- Edward F. Covill
- J. Thomas Harrington
- John A. George
- Timothy C. Mayer