Accession Number : ADA266538


Title :   Face-Gear Drives: Design, Analysis, and Testing for Helicopter Transmission Applications


Descriptive Note : Technical memo.


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


Personal Author(s) : Litvin, F L ; Wang, J C ; Bossler, R B , Jr ; Chen, Y J ; Heath, G


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a266538.pdf


Report Date : Oct 1992


Pagination or Media Count : 16


Abstract : The use of face-gears in helicopter transmissions was explored. A light-weight, split-torque transmission design utilizing face-gears is described. Face-gear design and geometry were investigated. Topics included tooth generation, limiting inner and outer radii, tooth contact analysis, contact ratio, gear eccentricity, grinding, and structural stiffness. Design charts were developed to determine minimum and maximum face-gear inner and outer radii. An analytical study showed that the face-gear drive is relatively insensitive to gear misalignment with respect to transmission errors, but the tooth contact is affected by misalignment. A method of localizing the bearing contact to permit operation with misalignment was explored. Two new methods for grinding of the face-gear tooth surfaces were also investigated. The proper choice of shaft stiffness enabled good load sharing in the split-torque transmission design. Face-gear experimental studies were also conducted. These tests demonstrated the feasibility of face-gears in high-speed, high-load applications such as helicopter transmissions.... Transmissions (Machine Elements), Gears, Design, Helicopters.


Descriptors :   *HELICOPTERS , *TRANSMISSION GEARS , TEST AND EVALUATION , VELOCITY , COMPUTERIZED SIMULATION , COMPUTER AIDED DESIGN , WEIGHT , GEOMETRY , BEARINGS , GEARS , DRIVE SHAFTS , GEAR TEETH , ECCENTRICITY , GRINDING , RADIUS(MEASURE) , TORQUE , MISALIGNMENT , MACHINES , MECHANICAL ENGINEERING , ERRORS , STIFFNESS , SENSITIVITY , SURFACES


Subject Categories : Aircraft


Distribution Statement : APPROVED FOR PUBLIC RELEASE