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

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.

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1972
Accession Number
AD0752579

Entities

People

  • H. Sternfeld
  • J. Schairer
  • R. Spencer

Organizations

  • Boeing Rotorcraft Systems

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Absorption
  • Aircraft Equipment
  • Aircrafts
  • Airframes
  • Contracts
  • Data Acquisition
  • Flight Crews
  • Frequency Bands
  • Helicopters
  • Measurement
  • Military Aircraft
  • Noise Reduction
  • Resonant Frequency
  • Rotary Wing Aircraft
  • Test Methods
  • Transmission Loss
  • Wear Resistance

Fields of Study

  • Engineering

Readers

  • Polymer Science and Engineering.
  • Structural Dynamics.
  • Tribology (the study of the boundary interaction between sliding surfaces, lubrication, wear and friction).