Accession Number : ADA180364

Title :   Vibration Characteristics of OH-58A Helicopter Main Rotor Transmission.

Descriptive Note : Technical paper,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER

Personal Author(s) : Lewicki,David G ; Coy,John J

PDF Url : ADA180364

Report Date : Apr 1987

Pagination or Media Count : 18

Abstract : Experimental vibration tests covering a range of torque and speed conditions were performed on the OH-58A helicopter main rotor transmission at the NASA Lewis Research Center. Signals from accelerometers located on the transmission housing were analyzed by using Fourier spectra, power spectra, power spectral density functions, and averaging techniques. Most peaks of the Fourier spectra occurred at the spiral bevel and planetary gear mesh harmonics. The highest level of vibration occurred at the spiral bevel and planetary gear mesh harmonics. The highest level of vibration occurred at the spiral bevel meshing frequency. Transmission speed and vibration measurement location had a significant effect on measured vibration; transmission torque and measurement direction had a small effect.

Descriptors :   *VIBRATION, *HELICOPTER ROTORS, AIRCRAFT NOISE, ACCELEROMETERS, FOURIER ANALYSIS, FUNCTIONS(MATHEMATICS), HOUSINGS, MEASUREMENT, POWER SPECTRA, RESEARCH FACILITIES, SPECTRA, SPECTRAL ENERGY DISTRIBUTION, TEST METHODS, TORQUE, TRANSMISSIONS(MECHANICAL), TRANSMITTANCE, VELOCITY

Subject Categories : Mechanics
      Helicopters

Distribution Statement : APPROVED FOR PUBLIC RELEASE