Accession Number : ADA293059

Title :   Spur, Helical, and Spiral Bevel Transmission Life Modeling.

Descriptive Note : Technical memo.,

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

Personal Author(s) : Savage, Michael ; Rubadeux, Kelly L. ; Coe, Harold H. ; Coy, John J.

PDF Url : ADA293059

Report Date : APR 1994

Pagination or Media Count : 13

Abstract : A computer program, TLIFE, which estimates the life, dynamic capacity, and reliability of aircraft transmissions, is presented. The program enables comparisons of transmission service life at the design stage for optimization. A variety of transmissions may be analyzed including: spur, helical, and spiral bevel reductions as well as series combinations of these reductions. The basic spur and helical reductions include: single mesh, compound, and parallel path plus reverted star and planetary gear trains. A variety of straddle and overhung bearing configurations on the gear shafts are possible as is the use of a ring gear for the output. The spiral bevel reductions include single and dual input drives with arbitrary shaft angles. The program is written in FORTRAN 77 and has been executed both in the personal computer DOS environment and on UNIX workstations. The analysis may be performed in either the SI metric or the English inch system of units. The reliability and life analysis is based on the two-parameter Weibull distribution lives of the component gears and bearings. The program output file describes the overall transmission and each constituent transmission, its components, and their locations, capacities, and loads. Primary output is the dynamic capacity and 90-percent reliability and mean lives of the unit transmissions and the overall system which can be used to estimate service overhaul frequency requirements. Two examples are presented to illustrate the information available for single element and series transmissions.

Descriptors :   *COMPUTER PROGRAMS, *LIFE EXPECTANCY(SERVICE LIFE), *COMPARISON, *AIRCRAFT EQUIPMENT, *TRANSMISSIONS(MECHANICAL), FREQUENCY, INPUT, OUTPUT, REQUIREMENTS, ANGLES, WEIBULL DENSITY FUNCTIONS, OPTIMIZATION, AIRCRAFT MAINTENANCE, CAPACITY(QUANTITY), DYNAMICS, PARAMETERS, MESH, REDUCTION, TRANSMITTANCE, FORTRAN, RELIABILITY, CONFIGURATIONS, DRIVES, WORK STATIONS, PLANETARY GEARS, SHAFTS(MACHINE ELEMENTS), BEARINGS, MICROCOMPUTERS, STATISTICAL DISTRIBUTIONS, RINGS, COMPUTER FILES, LIFE TESTS, GEARS, HELIXES.

Subject Categories : Computer Programming and Software
      Aircraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE