Accession Number:

AD0752579

Title:

An Investigation of Helicopter Transmission Noise Reduction by Vibration Absorbers and Damping

Descriptive Note:

Final rept.

Corporate Author:

BOEING VERTOL CO PHILADELPHIA PA

Personal Author(s):

Report Date:

1972-08-01

Pagination or Media Count:

174.0

Abstract:

A test program was conducted to evaluate the effect of dynamic absorbers and damping on the noise generated by a CH-47 rotor transmission. Comparison was made between predicted and measured results, and a method for comparing the efficiency of various methods of transmission noise reduction was developed. Gear damping was achieved by filling the gear shafts with Viton, and by a ring of Viton on the spiral bevel ring gear. Constrained layer damping was also used on the outside of the planetary ring gear.

Subject Categories:

  • Helicopters
  • Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE