Accession Number : ADA318758

Title :   A Method to Analyze and Optimize the Load Sharing of Split Path Transmissions.

Descriptive Note : Technical memo,

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

Personal Author(s) : Krantz, Timothy L.

PDF Url : ADA318758

Report Date : SEP 1996

Pagination or Media Count : 21

Abstract : Split-path transmissions are promising alternatives to the common planetary transmissions for rotorcraft. Heretofore, split-path designs proposed for or used in rotorcraft have featured load-sharing devices that add undesirable weight and complexity to the designs. A method was developed to analyze and optimize the load sharing in split-path transmissions without load-sharing devices. The method uses the clocking angle as a design parameter to optimize for equal load sharing. In addition, the clocking angle tolerance necessary to maintain acceptable load sharing can be calculated. The method evaluates the effects of gearshaft twisting and bending, tooth bending, Hertzian deformations within bearings, and movement of bearing supports on load sharing. It was used to study the NASA split-path test gearbox and the U.S. Army's Comanche helicopter main rotor gearbox. Acceptable load sharing was found to be achievable and maintainable by using proven manufacturing processes. The analytical results compare favorably to available experimental data.

Descriptors :   *TRANSMISSIONS(MECHANICAL), OPTIMIZATION, AIRCRAFT MAINTENANCE, HELICOPTERS, DYNAMIC LOADS, AIRCRAFT DESIGN.

Subject Categories : Helicopters

Distribution Statement : APPROVED FOR PUBLIC RELEASE